39 results on '"Andreas Constantopoulos"'
Search Results
2. Immunization of Preterm Infants With 10-Valent Pneumococcal Conjugate Vaccine
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Andreas Constantopoulos, Antigoni Tsirka, Nancy François, Vassiliki Papaevangelou, Dorota Borys, Marina Anagnostakou, Jose Manuel Merino, Dimitrios Kafetzis, Juan-Carlos Tejedor, Fani Athanassiadou, Lode Schuerman, and Felix Omeñaca
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Male ,Immunization, Secondary ,Booster dose ,medicine.disease_cause ,Pneumococcal Infections ,Haemophilus influenzae ,Pneumococcal Vaccines ,Conjugate vaccine ,Humans ,Medicine ,Vaccines, Conjugate ,biology ,business.industry ,Immunogenicity ,Vaccination ,Infant, Newborn ,Infant ,Titer ,Immunization ,Pediatrics, Perinatology and Child Health ,Immunology ,biology.protein ,Female ,Antibody ,business ,Infant, Premature - Abstract
OBJECTIVE: The safety and immunogenicity of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine (PHiD-CV) in preterm infants were assessed in this study. METHODS: Three parallel groups of infants received 3-dose primary immunization with PHiD-CV at 2, 4, and 6 months of age and a booster dose at 16 to 18 months: preterm I (gestation period ≥ 27 and RESULTS: The incidence of solicited general symptoms was similar across groups, and the frequency of grade 3 general symptoms was low. Incidences of redness and swelling were generally lower in preterm infants. PHiD-CV was immunogenic for each of the 10 vaccine pneumococcal serotypes (postprimary, ≥92.7% of infants reached enzyme-linked immunosorbent assay antibody concentrations ≥ 0.2 μg/mL and postbooster, ≥97.6%) and for protein D, with a trend for lower postprimary geometric mean antibody concentrations and opsonophagocytic activity (OPA) titers in preterm infants for some pneumococcal serotypes. Postbooster, ≥91.9% of subjects in each group had an OPA titer ≥ 8 for each of the vaccine serotypes. Pneumococcal antibody concentrations and OPA titers after priming and booster vaccination were comparable between the 2 preterm groups. CONCLUSIONS: PHiD-CV was well tolerated and immunogenic in preterm infants when given as a 3-dose primary vaccination, with robust enzyme-linked immunosorbent assay antibody and OPA booster responses in the second year of life.
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- 2011
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3. Adolescents Dealing with Sexuality Issues: A Cross-Sectional Study in Greece
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Elena Critselis, Despoina Tounissidou, Ioannis Deligiannis, Artemis Tsitsika, Eleftheria Konstantoulaki, Vana Papaevagelou, Marisa Tsolia, Andreas Constantopoulos, Vasiliki Dimitrakopoulou, Donald E. Greydanus, Dimitrios Kafetzis, and Vasiliki Bountziouka
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Male ,Health Knowledge, Attitudes, Practice ,Adolescent ,Cross-sectional study ,Sexual Behavior ,media_common.quotation_subject ,Population ,Psychological intervention ,Human sexuality ,Choice Behavior ,Developmental psychology ,Humans ,Medicine ,Girl ,education ,Contraception Behavior ,media_common ,education.field_of_study ,Greece ,business.industry ,Data Collection ,Obstetrics and Gynecology ,General Medicine ,Sexual intercourse ,Cross-Sectional Studies ,Family planning ,Pediatrics, Perinatology and Child Health ,Female ,business ,Psychosocial ,Demography - Abstract
To evaluate the prevalence of sexual activity and contraception methods used by Greek adolescents. To assess the effect of various factors in the decision making on sexual activity.A cross-sectional study design was applied. SETTING-PARTICIPANTS: The population (N = 1538) consisted of a random sample, stratified according to locality and population density, of 20 public junior high and high schools located in the urban district of Athens, Greece.Anonymous self-completed questionnaires were used to assess sexual practices, contraception methods, and factors affecting sexual activity choices.Spearman association calculations and chi-square were used, while regression analysis models were also applied.We examined the sexual practices among Greek adolescents, and indicated the psychosocial factors that may influence adolescents' sexual behavior.16% of the adolescents have had sexual intercourse, while the boy/girl ratio was 3/1 (P0.05). Mean age of sexual debut was 14 +/- 1.5 years. An additional 20% have had any other sexual experience at a mean age 13.5 +/- 1.5 years. Although sexually active adolescents generally use condoms (90.6%), only 32% use them properly (at every and throughout sexual contact). At least half of them do not have adequate protection (no method used or unreliable methods applied), while 8.2% of the girls have used emergency contraception. Adolescents with unstable home environment (divorce, recent death, not living with mother) or sexually experienced peers, as well as those that seek sexual education from siblings or friends have higher possibilities of being sexually active.Greek adolescents can be sexually active at a young age and they need sexual education on safe sex practices.
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- 2010
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4. Adolescent Obesity is Associated with High Ambulatory Blood Pressure and Increased Carotid Intimal-Medial Thickness
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S. Stabouli, Andreas Constantopoulos, Christos Papamichael, Vasilios Kotsis, and Nikos Zakopoulos
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Male ,Risk ,medicine.medical_specialty ,Ambulatory blood pressure ,Adolescent ,Hemodynamics ,Statistics, Nonparametric ,Internal medicine ,medicine ,Humans ,Obesity ,Ultrasonography ,Greece ,business.industry ,Case-control study ,Blood Pressure Monitoring, Ambulatory ,Tunica intima ,medicine.disease ,Carotid Arteries ,Cholesterol ,Endocrinology ,medicine.anatomical_structure ,Blood pressure ,Case-Control Studies ,Hypertension ,Pediatrics, Perinatology and Child Health ,Ambulatory ,Cardiology ,Female ,Tunica Intima ,business ,Body mass index - Abstract
To investigate 24-hour ambulatory blood pressure, lipid profiles, and carotid artery intimal-medial thickness (IMT) in adolescents with and without obesity.Ambulatory blood pressure data from 93 consecutive adolescents referred to our hypertension center for possible hypertension were analyzed. Fasting serum glucose and lipid concentrations were measured in all subjects. Carotid artery IMT was also measured by B-mode ultrasound imaging in all patients. Obesity was defined as body mass indexor =95(th) percentile for age and sex. Twenty-two of the subjects were obese and 71 nonobese.Mean 24-hour, daytime, and nighttime systolic blood pressures were significantly higher in obese subjects compared with nonobese subjects (P.002). Twenty-four-hour, daytime, and nighttime pulse pressures were also significantly higher in obese subjects (P.001). The magnitude of systolic white coat effect was significantly higher in obese subjects (P.006) and white coat hypertension was significantly more frequent in obese subjects (P.0001). Obese subjects had higher triglycerides (P.001) and lower HDL cholesterol (P.01) than nonobese subjects. Finally, obese adolescents had thicker mean IMT of internal carotid arteries than nonobese adolescents (P.005).Obese adolescents have higher ambulatory blood pressure and higher carotid artery IMT, possibly indicating an early course of obesity-related hypertension and carotid artery structural alterations.
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- 2005
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5. Human metapneumovirus as a causative agent of acute bronchiolitis in infants
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Maria Tsolia, Dimitrios Gourgiotis, Dimitrios Kafetzis, Stelios Psarras, Nikolaos G. Papadopoulos, Georgia Liapi-Adamidou, Apostolos Bossios, Andreas Constantopoulos, and Paraskevi Xepapadaki
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Paramyxoviridae ,viruses ,RTI, respiratory tract infection ,Respiratory syncytial virus ,Polymerase Chain Reaction ,Article ,Pneumovirinae ,PCR, polymerase chain reaction ,Human metapneumovirus ,Virology ,Nasopharynx ,Diagnosis ,Medicine ,Bronchiolitis, Viral ,Humans ,Mononegavirales ,hMPV, human metapneumovirus ,Paramyxoviridae Infections ,biology ,Respiratory tract infections ,business.industry ,Viral Epidemiology ,virus diseases ,NPW, nasopharyngeal wash ,Infant ,Pneumovirus ,medicine.disease ,biology.organism_classification ,respiratory tract diseases ,RV, human rhinovirus ,Infectious Diseases ,Bronchiolitis ,Immunology ,Acute Disease ,RSV, respiratory syncytial virus ,Metapneumovirus ,Seasons ,business - Abstract
Background: Human Metapneumovirus (hMPV), has been recently isolated from children with acute respiratory tract infections (RTIs), including bronchiolitis, and classified in the Pneumovirinae subfamily within the Paramyxoviridae family. Objectives: Since most bronchiolitis studies fail to detect any viral pathogen in part of the samples, we sought for the presence of hMPV in a well characterized bronchiolitis cohort. Study design: Nasal washes were obtained from 56 children admitted to the hospital for acute bronchiolitis. RNA extraction and subsequent RT-PCR were used to detect hMPV, and correlated the presence of the virus with clinical characteristics of the disease. Results and conclusions: PCR revealed the presence of hMPV in 16% of bronchiolitis cases, whereas respiratory syncytial virus (RSV; 67.9%) was the most frequently encountered viral pathogen. hMPV was identified either as a unique viral pathogen or co-existed with RSV, with whom they shared a similar seasonal distribution. There were no differences in disease characteristics, either clinical or laboratory, between bronchiolitis cases where hMPV was present and those caused by RSV or other viral pathogens. These findings suggest that hMPV is a common and important causative agent in infants with bronchiolitis, with clinical characteristics similar to that of RSV.
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- 2004
6. Is peptic ulcer a common cause of upper gastrointestinal symptoms?
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Eleftheria Roma, Yota Kafritsa, Roula Liakou, Andreas Constantopoulos, and Joanna Panayiotou
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Male ,medicine.medical_specialty ,Adolescent ,Spirillaceae ,Gastroenterology ,Endoscopy, Gastrointestinal ,Helicobacter Infections ,Internal medicine ,Humans ,Medicine ,Medical history ,Stomach Ulcer ,Family history ,Child ,Retrospective Studies ,Helicobacter pylori ,medicine.diagnostic_test ,biology ,business.industry ,Infant ,Retrospective cohort study ,biology.organism_classification ,digestive system diseases ,Endoscopy ,El Niño ,Child, Preschool ,Duodenal Ulcer ,Pediatrics, Perinatology and Child Health ,Cohort ,Female ,business - Abstract
The aim of the study was to investigate retrospectively a cohort of children with peptic ulcer disease during a period that covers the recent changes in diagnosis and management of the disease. Over a period of 9 years, 2550 children underwent upper gastrointestinal endoscopy for various reasons. All children, in whom a diagnosis of primary peptic ulcer was established, were included in the study. Previous and current medical history, family history, endoscopic and histological outcome were evaluated and the children were regularly followed-up on an out-patient basis. Primary peptic ulcer was diagnosed in 52 (10 gastric and 42 duodenal, 2%) out of 2550 children. The median age of children with gastric ulcer was 6.5 years, whereas of those with duodenal ulcer was 10.5 years (P=0.04). With regard to clinical symptoms no significant difference was found between children with and without ulcer. The prevalence of Helicobacter pylori infection was significantly higher in children with duodenal ulcer (62%) compared to those with gastric ulcer (20%; P0.001). At first follow-up visit, 1 month after the end of treatment, 19 symptomatic children underwent a repeat endoscopy, which showed ulcer healing in 95% and failure in H. pylori eradication in 27%. During the long-term follow-up (median 3.5 years), six children became symptomatic. Two of them had duodenal ulcer associated with positive H. pylori.Peptic ulcer disease is an uncommon disorder in childhood with non specific clinical features; it seems that efficient treatment and successful Helicobacter pylori eradication result in clinical improvement and cure as well as in long-term healing of ulcers.
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- 2001
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7. Seasonal Variation of Neonatal and Infant Deaths by Cause in Greece
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Nikolaos Kalpoyannis, Klea Katsouyanni, Ipatia A. Apostolidou, Dimitrios Trichopoulos, Andreas Constantopoulos, and Giota Touloumi
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Rural Population ,Pediatrics ,medicine.medical_specialty ,Urban Population ,Population ,Poison control ,Risk Factors ,Cause of Death ,Infant Mortality ,Injury prevention ,medicine ,Humans ,education ,Cause of death ,education.field_of_study ,Greece ,business.industry ,Mortality rate ,Age Factors ,Infant, Newborn ,Public Health, Environmental and Occupational Health ,Infant ,Seasonality ,Sudden infant death syndrome ,medicine.disease ,Infant mortality ,Population Surveillance ,Seasons ,business ,Demography - Abstract
The seasonal variation of neonatal and infant deaths in Greece was analyzed for nine consecutive years (1979-1987) by cause of death, age of death and urbanization of permanent residence. Data were supplied by the National Statistical Service of Greece. Statistical analysis was done using the Edward's method. The seasonal patterns of the number of deaths and death rates were similar. Neonatal deaths in total did not show significant seasonality but postneonatal deaths showed seasonal variation with a peak in the winter, more evident in rural areas. Neonatal deaths from prematurity showed statistically significant seasonal variation with a peak in May. Postneonatal deaths from infections and mainly those from pneumonia showed very significant seasonal variation with a peak in February that was more prominent in rural areas. Seasonal pattern with peak in late winter was also found for postneonatal deaths from injuries. The seasonal patterns for neonatal and postneonatal deaths from sudden infant death syndrome were suggestive of an increased occurrence during the winter months mainly in urban areas.The data were provided by a search in the National Statistical Service of Greece (NSSG), and covered the period from January 1, 1979 through December 31, 1987, for all infant deaths in Greece. Data on live births were taken from the annual statistical reports of NSSG. Statistical analysis was done by means of the Edward's method. The seasonal patterns of the number of deaths and death rates (per 1000 live-born) were almost identical for the 2 parts of the period studied, for the years 1979 and 1987. 1979-83 and 1984-87 were treated separately for the neonatal period and for the postneonatal period. The number of neonatal and early neonatal deaths did not show significant seasonality in the total period, in either the urban or the rural areas, although the peaks for early neonatal deaths in 8 out of 9 studied years were in the spring and summer. The maximum number of postneonatal deaths was observed during January-February, representing a 60-90% increase compared to the minimum number of deaths, and the difference was more evident in the rural areas of residence in 1979-83. Neonatal deaths from prematurity showed statistically significant seasonal variation with a peak in May, more prominent in urban areas. Postneonatal deaths from infections showed statistically significant seasonal variation with a peak in February more prominent in rural areas and in the 1979-83 period. Postneonatal deaths from pneumonia showed very significant seasonal variation, with a peak in February more prominent in rural areas and in the 1979-83 period. Neonatal deaths from sepsis showed increased occurrence in May, whereas postneonatal deaths from sepsis and from enteric infections did not show significant seasonality. Deaths from injuries showed a statistically significant peak during January-February, in both urban and rural areas, in the postneonatal period. Neonatal and postneonatal deaths from sudden infant death syndrome were more common during the winter (December-January-February) in urban areas.
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- 1994
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8. Impact of influenza infection on children's hospital admissions during two seasons in Athens, Greece
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P. Drossatou, Andreas Constantopoulos, V. Georgiou, M. Mavrikou, Nikolaos G. Papadopoulos, Z. Sakkou, Dimitris A. Kafetzis, M. Tsolia, Fotini Stripeli, and Elena Critselis
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Male ,Pediatrics ,medicine.medical_specialty ,Adolescent ,Urban Population ,Acute otitis media ,medicine.drug_class ,Antibiotics ,Population ,Athens greece ,Influenza season ,Seizures ,Nasopharynx ,Epidemiology ,Influenza, Human ,Prevalence ,Medicine ,Humans ,Prospective Studies ,education ,Child ,education.field_of_study ,General Veterinary ,General Immunology and Microbiology ,Greece ,business.industry ,Reverse Transcriptase Polymerase Chain Reaction ,Public Health, Environmental and Occupational Health ,virus diseases ,Routine immunization ,Infant ,Hospitalization ,Otitis Media ,Infectious Diseases ,Child, Preschool ,Molecular Medicine ,RNA, Viral ,Female ,business - Abstract
A prospective epidemiologic surveillance of hospitalizations associated with influenza was conducted in order to calculate population-based hospitalization rates. Eligible children were 6 months to 13 years of age and were admitted to one of the two large children's hospitals in the Athens area during two influenza seasons. Nasopharyngeal aspirates were tested for influenza by a polymerase reaction assay. Influenza accounted for 9.9-11.8% of all admissions during the influenza season and the overall annual rate of hospitalizations was 13.6-16.8 cases per 10,000 children being highest for children under 5 years of age (26-31.2/10,000 children). Febrile seizures and acute otitis media were the two most common complications associated with influenza and antibiotics were administered to 61% of flu positive patients. Influenza is associated with high hospitalization rates among young children and these may be substantially reduced with the introduction of routine immunization.
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- 2010
9. Left ventricular mass in normotensive, prehypertensive and hypertensive children and adolescents
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Andreas Constantopoulos, Stella Stabouli, Savvas Toumanidis, Nikos Zakopoulos, Christince Karagianni, Zoe Rizos, and Vasilios Kotsis
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Nephrology ,Male ,medicine.medical_specialty ,Ambulatory blood pressure ,Adolescent ,Heart Ventricles ,Standard score ,Left ventricular hypertrophy ,Prehypertension ,Left ventricular mass ,Internal medicine ,Prevalence ,Medicine ,Humans ,Child ,Ultrasonography ,business.industry ,Organ Size ,medicine.disease ,Obesity ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Hypertension ,Cardiology ,Female ,Hypertrophy, Left Ventricular ,business ,Body mass index - Abstract
The purpose of this study was to investigate differences in left ventricular mass index (LVMI) and the prevalence of left ventricular hypertrophy (LVH) in children and adolescents classified as normotensives, prehypertensives and hypertensives by ambulatory blood pressure (BP) levels. A total of 124 consecutive children and adolescents aged 5 to 18 years were analysed. Patients underwent 24 h ambulatory blood pressure monitoring (ABPM) and echocardiography. Hypertensive and prehypertensive subjects had significantly higher LVMI than normotensives (36.8 +/- 8.4 g/m(2.7) and 34.1 +/- 3.4 g/m(2.7) vs. 29.5 +/- 8.3 g/m(2.7), P0.01 and P0.05, respectively). In multivariate analysis predictors for LVMI were body mass index (BMI) z score and hypertension (R-squared = 0.31). LVMI values in hypertensive subjects were significantly higher than those of normotensives even after adjustment for age, sex and BMI z score. The prevalence of LVH was significantly higher in the prehypertensive compared to normotensive subjects, and was equal to that of the hypertensive subjects. Hypertension and prehypertension in children and adolescents were associated with pathologically elevated LVMI values. If confirmed in a larger group prehypertensive children may be at risk for target organ damage similar to the condition of established hypertension.
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- 2008
10. Human rhinoviruses in otitis media with effusion
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M. Xatzipsalti, Andreas Constantopoulos, T. Bairamis, F. M. Chantzi, Dimitris A. Kafetzis, G. Liapi, M. Tsiakou, N. Bournousouzis, and Nikolaos G. Papadopoulos
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Male ,medicine.medical_specialty ,Rhinovirus ,medicine.medical_treatment ,Immunology ,medicine.disease_cause ,Gastroenterology ,Asymptomatic ,Myringotomy ,Atopy ,Risk Factors ,Internal medicine ,Surveys and Questionnaires ,otorhinolaryngologic diseases ,medicine ,Immunology and Allergy ,Humans ,Family history ,Child ,Enterovirus ,Skin Tests ,Picornaviridae Infections ,Respiratory tract infections ,business.industry ,Otitis Media with Effusion ,medicine.disease ,Otitis ,Cross-Sectional Studies ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,RNA, Viral ,Female ,medicine.symptom ,business - Abstract
Frequent viral upper respiratory tract infections (URTI) are considered to be risk factors for otitis media with effusion (OME). Atopy has also been associated with both OME and viral infections. The aim of this study was to evaluate the presence of viruses in middle ear effusions (MEE) in children 2-7 yr old with OME, and to determine risk factors for virus detection in the MEE. MEE samples, collected at the time of myringotomy from 37 children with OME were assessed. Physical examination, skin prick tests and a standardized questionnaire on OME and allergy were also performed. Viral RNA was detected by the use of reverse transcription PCR (RT-PCR). Fifteen samples (40.5%) were positive for rhinovirus (RV). One enterovirus and no other respiratory viruses were detected. Two out of five (40%), 3/7 (43%) and 10/25 (40%) were positive for RV in acute, subacute and chronic cases, respectively. Children with frequent episodes of OM, with early onset of OM (
- Published
- 2006
11. Vascular endothelial growth factor-mediated induction of angiogenesis by human rhinoviruses
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Apostolos Bossios, Eleni Volonaki, M. Xatzipsalti, Nikolaos G. Papadopoulos, Dimitrios Gourgiotis, Photini Saxoni-Papageorgiou, Andreas Papapetropoulos, Harris Pratsinis, Stelios Tsigkos, Andreas Constantopoulos, Stelios Psarras, and Chrysanthi Skevaki
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Hypersensitivity, Immediate ,Male ,Vascular Endothelial Growth Factor A ,Umbilical Veins ,Adolescent ,Rhinovirus ,Angiogenesis ,viruses ,Immunology ,Inflammation ,Bronchi ,Biology ,medicine.disease_cause ,Cell Line ,Neovascularization ,chemistry.chemical_compound ,Multiplicity of infection ,stomatognathic system ,Nasopharynx ,medicine ,Immunology and Allergy ,Humans ,Child ,Picornaviridae Infections ,Neovascularization, Pathologic ,Endothelial Cells ,Epithelial Cells ,respiratory system ,Asthma ,respiratory tract diseases ,Up-Regulation ,Vascular endothelial growth factor ,Endothelial stem cell ,chemistry ,Respiratory epithelium ,Female ,medicine.symptom ,HeLa Cells - Abstract
Background Human rhinoviruses, major precipitants of asthma exacerbations, infect the lower airway epithelium inducing inflammation. The possibility that viral infection may mediate angiogenesis, thus contributing to airway remodeling, has not been evaluated. Objective To investigate whether epithelial infection with rhinovirus mediates angiogenesis in vitro , evaluate possible modulation by an atopic environment, and confirm angiogenic factor induction after in vivo rhinovirus infection. Methods Bronchial epithelial cells were infected with rhinovirus and levels of vascular endothelial growth factor (VEGF), and angiopoietins were measured. The angiogenic effect of epithelial products was assessed in in vitro models of angiogenesis. PBMCs, obtained from patients with atopic asthma and normal controls, were exposed to rhinovirus; the ability of supernatants from these cultures differentially to affect rhinovirus-mediated epithelial VEGF production was evaluated. VEGF levels were measured in respiratory secretions from patients with asthma, before and during rhinovirus-induced exacerbations. Results Epithelial infection with rhinovirus specifically stimulated mRNA expression and release of VEGF, but not angiopoietins, in a time-dependent and dose-dependent manner. Supernatants from these cultures were able to induce angiogenesis in vitro , significantly inhibited by a neutralizing anti-VEGF antibody. When bronchial cells were exposed to supernatants of rhinovirus-infected mononuclear cells from normal subjects or atopic patients with asthma, VEGF induction was significantly higher under the influence of the atopic environment. VEGF was elevated during rhinovirus-associated asthma exacerbations. Conclusion Rhinovirus infection, a frequent event, induces VEGF production in bronchial epithelial cells and human airways, an effect enhanced in an atopic environment. Rhinovirus-associated, VEGF-mediated angiogenesis may contribute to airway remodeling in asthma.
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- 2005
12. White-coat and masked hypertension in children: association with target-organ damage
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Christos Papamichael, S. Stabouli, Andreas Constantopoulos, Savvas Toumanidis, Nikos Zakopoulos, and Vasilios Kotsis
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Nephrology ,Male ,medicine.medical_specialty ,Ambulatory blood pressure ,Adolescent ,White coat hypertension ,Muscle hypertrophy ,Internal medicine ,medicine ,Prevalence ,Humans ,Child ,business.industry ,Blood Pressure Monitoring, Ambulatory ,medicine.disease ,Target organ damage ,Masked Hypertension ,Blood pressure ,Carotid Arteries ,Pediatrics, Perinatology and Child Health ,Ambulatory ,Hypertension ,Cardiology ,Female ,Hypertrophy, Left Ventricular ,business ,Tunica Intima - Abstract
White-coat hypertension (WCH) and masked hypertension have been associated with increased cardiovascular risk in adults. In the current study, we investigated: (a) the prevalence of WCH and masked hypertension in pediatric patients and (b) the association of these conditions with target organ damage. A total of 85 children underwent office blood pressure measurements, 24-h ambulatory blood pressure monitoring, echocardiography and ultrasonography of the carotid arteries. Subjects with both office and ambulatory normotension or hypertension were characterized as confirmed normotensives or hypertensives, respectively; WCH was defined as office hypertension with ambulatory normotension and masked hypertension as office normotension and ambulatory hypertension. WCH was found in 12.9% and masked hypertension in 9.4% of the subjects. WCH was significantly more prevalent in obese subjects, while masked hypertension was only present in non-obese ones. Confirmed and masked hypertensives had significantly higher left ventricular mass index than confirmed normotensives (34.0+/-5.8 g/m(2.7), 31.9+/-2.9 g/m(2.7) and 25.3+/-5.6 g/m(2.7), respectively, P
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- 2005
13. Etiology of community-acquired pneumonia in hospitalized school-age children: evidence for high prevalence of viral infections
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Dimitris A. Kafetzis, Maria Tsolia, Nikolaos G. Papadopoulos, K. Kallergi, Andreas Constantopoulos, Dimitrios Gourgiotis, Apostolos Bossios, M. Paldanius, Stelios Psarras, and H. Audi
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Microbiology (medical) ,Male ,Mycoplasma pneumoniae ,Atypical bacteria ,Adolescent ,Rhinovirus ,viruses ,Pneumonia, Viral ,medicine.disease_cause ,Major Articles ,Community-acquired pneumonia ,Pneumonia, Mycoplasma ,medicine ,Pneumonia, Bacterial ,Prevalence ,Humans ,Child ,Chlamydophila Infections ,Picornaviridae Infections ,business.industry ,Viral Epidemiology ,Chlamydophila pneumoniae ,medicine.disease ,Virology ,Community-Acquired Infections ,Pneumonia ,Infectious Diseases ,Child, Preschool ,Immunology ,Coinfection ,RNA, Viral ,Female ,Viral disease ,business ,Child, Hospitalized - Abstract
Background. Community-acquired pneumonia (CAP) in young children is most commonly associated with viral infections; however, the role of viruses in CAP of school-age children is still inconclusive. Methods. Seventy-five school-age children hospitalized with CAP were prospectively evaluated for the presence of viral and bacterial pathogens. Nasopharyngeal washes were examined by polymerase chain reaction for viruses and atypical bacteria. Antibody assays to detect bacterial pathogens in acute-phase and convalescent-phase serum samples were also performed. Results. A viral infection was identified in 65% of cases. Rhinovirus RNA was detected in 45% of patients; infection with another virus occurred in 31%. The most common bacterial pathogen was Mycoplasma pneumoniae, which was diagnosed in 35% of cases. Chlamydia pneumoniae DNA was not detected in any patient; results of serological tests were positive in only 2 patients (3%). Mixed infections were documented in 35% of patients, and the majority were a viral-bacterial combination. Conclusions. The high prevalence of viral and mixed viral-bacterial infections supports the notion that the presence of a virus, acting either as a direct or an indirect pathogen, may be the rule rather than the exception in the development of CAP in school-age children requiring hospitalization.
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- 2003
14. BEHAVIORAL PROBLEMS IN CHILDREN WITH LEARNING DIFFICULTIES ACCORDING TO THEIR PARENTS AND TEACHERS
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John Gardelis, Georgia Koltsida, Katerina Nikolaou, Andreas Constantopoulos, Panagiotis Diakakis, Styella Tsitoura, and Kiriaki Ventouri
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Pediatrics ,medicine.medical_specialty ,business.industry ,Irritability ,medicine.disease ,Comorbidity ,Pediatrics, Perinatology and Child Health ,Stress (linguistics) ,medicine ,Anxiety ,medicine.symptom ,Social isolation ,business ,Depression (differential diagnoses) ,Clinical psychology - Abstract
INTRODUCTION: Learning difficulties (LDs) are associated with increased comorbidity, especially depression and anxiety. Studies have shown that 24% to 52% of children with LDs present with behavioral problems (BPs). OBJECTIVE: The aim of our study was to evaluate whether parents' and teachers' opinions concerning BPs in children with LDs are identical. METHODS: For this purpose, 658 students (aged 7–10 years) in elementary schools were evaluated by specialized questionnaires for parents and teachers. Of those students, 102 (15.5%) were identified as having LDs according to their teachers. The questions regarded symptoms of depression, anxiety/stress, irritability, and other BPs. RESULTS: Our findings in children with LDs are summarized in Table 1. CONCLUSIONS: BPs resulting from reduced self-confidence and anxiety/stress were observed at a higher rate by the teachers than by the parents, who more often acknowledged symptoms of social isolation and aggressive behavior. Stress was the BP about which parents and teachers gave identical replies. TABLE 1.Behavioral Problems in Children With LDsTeachers and Parents Agree That There Are No BPs, %Teachers and Parents Agree That There Are BPs, %Only the Teachers Consider That There Is a BP, %Only the Parents Consider That There Is a BP, %Reduced self-confidence24.626.342.17.0Complains of headache/bellyache19.428.437.314.9Feeling tired frequently13.624.256.16.1Other children tease him/her42.613.216.227.9Being alone, without friends37.111.335.516.1Being unreliable48.412.510.928.1Often fights with other children48.520.613.217.6Increased irritability36.820.611.830.9
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- 2008
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15. Juvenile chronic arthritis profile in Greek children
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Christine Dracou, Nikki Constantinidou, and Andreas Constantopoulos
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musculoskeletal diseases ,Male ,Anti-nuclear antibody ,Adolescent ,Arthritis ,Fluorescent Antibody Technique ,Enzyme-Linked Immunosorbent Assay ,Human leukocyte antigen ,Uveitis ,Antigen ,Medicine ,Humans ,Age of Onset ,Child ,Retrospective Studies ,Chi-Square Distribution ,Greece ,business.industry ,Incidence (epidemiology) ,Autoantibody ,Infant ,medicine.disease ,Arthritis, Juvenile ,Antibodies, Antinuclear ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Immunology ,Female ,Age of onset ,business - Abstract
Background: Juvenile chronic arthritis (JCA) is the commonest autoimmune rheumatic disease in childhood and presents different clinical subtypes. Juvenile chronic arthritis is considered to be of a polygenic nature and its genetic background is still under investigation. The clinical profile of JCA in the Greek population has not been studied completely. This study retrospectively analyzed the clinical and immunological features of JCA in Greek children presented between 1989 and 1994. Human leukocyte antigen (HLA)-positive or -negative associations in the different clinical subtypes were also detected. The findings of this study were correlated with those reported from other populations. Methods and results: Antinuclear antibodies (ANA) anti-ds DNA and anti-extractable nuclear antigen antibodies were estimated by immunofluorescent and ELISA assays. Human leukocyte antigen typing was performed by microlymphocytotoxicity. using immunobeads. The peak ages of JCA onset were between 2 and 5 years and also between 9 and 12 years. There was a high female predominance in pauciarticular and polyarticular groups. The most common disease was pauciarticular (58.7%) followed by systemic (25%) arthritis. The incidence of eye involvement was 12.5% and presented only in the pauciarticular group. Overall, ANA positivity was 53.7%, increasing to 90% in pauciarticular cases associated with chronic uveitis. In the early-onset (EOPA) pauciarticular subtype, positive-HLA associations with alleles DR11 and DR8 were shown. In the late onset pauciarticular (LOPA) group only B27 allele was increased. Conclusions: The results of this retrospective study did not reveal major differences between JCA in Greek children compared with other Caucasian series.
- Published
- 1999
16. Colitis induced by interaction of cyclosporine A and non-steroidal anti-inflammatory drugs
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Andreas Constantopoulos
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Diclofenac ,business.industry ,Anti-Inflammatory Agents, Non-Steroidal ,Indomethacin ,Drug interaction ,Pharmacology ,medicine.disease ,Colitis ,Arthritis, Rheumatoid ,Non steroidal anti inflammatory ,Rheumatoid arthritis ,Pediatrics, Perinatology and Child Health ,medicine ,Cyclosporine ,Humans ,Drug Interactions ,Female ,business ,Child ,Immunosuppressive Agents - Published
- 1999
17. Seventeen years of experience with chronic idiopathic thrombocytopenic purpura in childhood. Is therapy always better?
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Helen Platokouki, A Mitsika, Stavros Haidas, Andreas Constantopoulos, and S Aronis
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Male ,medicine.medical_specialty ,Pediatrics ,medicine.medical_treatment ,Splenectomy ,Thrombotic thrombocytopenic purpura ,Spontaneous remission ,Hemorrhagic Disorders ,Asymptomatic ,Adrenal Cortex Hormones ,hemic and lymphatic diseases ,Sepsis ,Medicine ,Humans ,Life Tables ,Child ,Cerebral Hemorrhage ,Retrospective Studies ,Purpura, Thrombocytopenic, Idiopathic ,Greece ,business.industry ,Incidence (epidemiology) ,Mortality rate ,Incidence ,Remission Induction ,Immunoglobulins, Intravenous ,Retrospective cohort study ,Hematology ,medicine.disease ,Thrombocytopenic purpura ,Combined Modality Therapy ,Surgery ,Oncology ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Female ,medicine.symptom ,business - Abstract
Between 1975 and 1992 450 children with idiopathic thrombocytopenic purpura (ITP) were diagnosed, and of those 100 (22%) developed the chronic form of the disease. Approximately half the patients with chronic ITP presented with mild to moderate hemorrhagic manifestations at the onset of purpura (30 cases) and/or later during the course of the disease (25 cases). The incidence of intracranial hemorrhage was 1%, and the mortality rate due to overwhelming septicemia after splenectomy was also 1%. Overall one-third of the patients received no therapy; two-thirds of them went into spontaneous remission within 8 months to 8 years from the onset of ITP. Steroids given in conventional or high doses (51 cases) achieved a transient (if any) rise in platelet count, but in no case were steroids curative. Remission related to intravenous immune globulin (IVIG) therapy was noticed in 38.5% of the children (10 of 26) after variable courses. The response rate to splenectomy was 95.0%. Ultimately the long-term outcome in children with chronic ITP was as follows: remission, 58 cases (spontaneous, 30; after IVIG therapy, 10; after splenectomy, 18); hemostatic platelet values, 22 cases (spontaneous, 16; after IVIG, 5; after splenectomy, 1). Thirteen children were lost in follow-up, and 7 remain thrombocytopenic but asymptomatic. These data indicate that chronic ITP in childhood runs a benign course in most cases and may remit with or without therapy even several years from onset. Therefore, therapeutic intervention has to be individualized, and splenectomy, which is not always safe, should be reserved for problematic cases that fail to respond to conventional therapeutic modalities.
- Published
- 1994
18. LEFT-VENTRICULAR MASS INDEX IN HYPERTENSIVE CHILDREN AND ADOLESCENTS
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Christine Karagianni, Andreas Constantopoulos, Nikos Zakopoulos, Savvas Toumanidis, Stella Stabouli, and Vasilios Kotsis
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medicine.medical_specialty ,Pediatrics ,Percentile ,Ambulatory blood pressure ,business.industry ,Diastole ,Prehypertension ,Left ventricular mass ,Internal medicine ,Pediatrics, Perinatology and Child Health ,Ambulatory ,Cardiology ,Medicine ,business - Abstract
OBJECTIVE: Our aim was to investigate differences in left-ventricular mass corrected for height2.7 (LVMI) in children and adolescents according to 24-hour ambulatory blood pressure (BP) levels. METHODS: A total of 67 consecutive children and adolescents aged 5 to 20 years were analyzed. Patients underwent 24-hour ambulatory BP monitoring and echocardiography. LVMI was calculated by using the Devereux equation. All subjects underwent 24-hour ambulatory blood pressure monitoring on a usual school day. Ambulatory hypertension was defined as mean daytime systolic BP and/or diastolic BP at ≥95th percentile for gender and height (n = 22). Prehypertension was defined as mean daytime systolic BP and/or diastolic BP at ≥90th percentile and RESULTS: LVMI was 28.3 ± 9.4 g/m2.7 (mean ± SD) in the normotensive subjects (n = 32), whereas it was 35.1 ± 8.7 g/m2.7 in the hypertensive subjects (n = 22), a difference that was significantly higher (P < .001, Mann-Whitney test). LVMI was 32.4 ± 5.4 g/m2.7 in prehypertensive subjects (n = 13), values that tended to be lower than the values of hypertensive subjects (P = .275) and significantly higher than the values of normotensive subjects (P < .05, Mann-Whitney test). CONCLUSIONS: Children and adolescents characterized as hypertensive or prehypertensive using the ambulatory blood pressure criteria exhibited significantly higher LVMI than normotensive subjects. Prehypertensive children may be at a similar risk for cardiovascular target-organ damage as that established for hypertensive children.
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- 2008
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19. Internet Use and Abuse in an Adolescent Population in Athens: Associations with Psychological Profile and Lifestyle of Users
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Andreas Constantopoulos, Georgios Kormas, Georgios Nassis, Maria Sfiri, Elli Sophia Tripodaki, Eleftheria Konstantoulaki, Helen Georgouli, Elisabeth K. Andrie, Aliki Freskou, and Artemis Tsitsika
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medicine.medical_specialty ,Internet use ,Nonsteroidal ,Suicide attempt ,business.industry ,education ,Clinical state ,Toxic substance ,Adolescent population ,chemistry.chemical_compound ,chemistry ,Pediatrics, Perinatology and Child Health ,medicine ,Epidemiologic data ,Medical prescription ,Psychiatry ,business - Abstract
INTRODUCTION: Use of the Internet has become very popular among youth, but phenomena of Web abuse with negative physical and psychosocial consequences have emerged. OBJECTIVE: The researchers' goal was to study Internet use and abuse by Greek adolescents and to identify the psychological profile and lifestyle of users. Intervention attempts will also be designed and discussed. METHODS: An Athens adolescent population representative sample of 315 (164 boys, 151 girls) high school students (mean age: 15 years) were included in the study. For Internet-addiction diagnosis, an international tool (Young's Internet Addiction Test questionnaire) was used. The Strengths and Difficulties Questionnaire was applied to screen for emotional and behavioral problems. Physical activity and physical fitness were also assessed with appropriate questions. Correlation and x2 statistics were performed by using SPSS (SPSS Inc, Chicago, IL). RESULTS: According to the results, 167 (53.4%) of 315 adolescents were using the Internet for >1 year, 82 (26%) of 315 reported daily use, and 25 (8%) of 315 reported >20 hours' use weekly. Boys were spending significantly more time using the Internet than girls (P < .05). According to Young's Questionnaire scoring, no youngster in our sample was addicted. However, in 28 (9.4%) of 315 adolescents, Young's Questionnaire scoring was suggestive of occasional or frequent problems of Internet overuse. The most frequent reason for using the Internet was games (P < .05), and 18 (5.8%) of 315 children in our sample were cyberbullying victims. There was a positive correlation of Internet use and hyperactivity according to the Strengths and Difficulties Questionnaire results (P < .05). Positive correlations were also noted for Internet use and delinquency (P < .001) as well as dysfunctional peer relationships (P < .001). CONCLUSIONS: Use of the Internet is popular among Greek youth, and it can be related to psychosocial problems if overused.
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- 2008
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20. MEASURING QUALITY OF LIFE IN GREEK CHILDREN: FIRST PSYCHOMETRIC RESULTS OF THE GREEK VERSION OF THE PEDIATRIC QUALITY OF LIFE INVENTORY (PEDSQL) 4.0 GENERIC CORE SCALES
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Vassiliki Papaevangelou, Andreas Constantopoulos, Konstantina Gkoltsiou, and Yannis Tountas
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medicine.medical_specialty ,education.field_of_study ,business.industry ,Population ,Construct validity ,Conjugate gaze ,Quality measurement ,humanities ,Quality of life (healthcare) ,Pediatrics, Perinatology and Child Health ,Physical therapy ,medicine ,Pilot test ,education ,business ,Socioeconomic status ,Reliability (statistics) ,Clinical psychology - Abstract
INTRODUCTION: Health-related quality of life concerning children is a growing field of research. The Pediatric Quality of Life Inventory (PedsQL) is a promising instrument that is available in age-appropriate versions and parallel forms for both children and their parents. OBJECTIVE: The purpose of this study was to evaluate the psychometric properties of the Greek translation of the PedsQL 4.0 generic core scales in a sample of healthy children. METHODS: After a successful pilot test, the Greek PedsQL was used in a cross-sectional study of 645 healthy 8- to 12-year-old schoolchildren and 567 of their caregivers within the framework of the European project (KIDSCREEN). Reliability of the instrument was assessed by Cronbach's α. Construct validity was assessed by exploring the intercorrelations between the 4 PedsQL subscales and between self- and proxy-report subscales. Impact of gender, health status, and socioeconomic class was detected. RESULTS: All PedsQL scales showed satisfactory reliability (>.70). Correlations among self-report subscales and between self- and proxy-report subscales were significant. Girls reported lower health-related quality of life than boys on the emotional-functioning subscale. There were significant differences in scores between low and high socioeconomic groups. Healthy children scored significantly higher on all self- and proxy-report scales. CONCLUSIONS: The PedsQL Greek version for children 8 to 12 years old is a valid and reliable instrument, replicating some of the earlier findings of the original version. The Greek PedsQL 4.0 version will be a valuable tool that can be used effectively in quality-of-life measurement in Greek clinical trials and population-based exercises.
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- 2008
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21. Rhinovirus infection induces cytotoxicity and delays wound healing in bronchial epithelial cells
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Apostolos Bossios, Andreas Constantopoulos, Nikolaos G. Papadopoulos, Photini Saxoni-Papageorgiou, Dimitrios Gourgiotis, Stelios Psarras, and Chrysanthi Skevaki
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Pulmonary and Respiratory Medicine ,Time Factors ,Vascular Cell Adhesion Molecule-1 ,Bronchi ,Respiratory Mucosa ,Biology ,Flow cytometry ,Cell Line ,medicine ,Cytotoxic T cell ,Humans ,Cytotoxicity ,lcsh:RC705-779 ,Wound Healing ,Picornaviridae Infections ,medicine.diagnostic_test ,Cell growth ,Research ,Epithelial Cells ,lcsh:Diseases of the respiratory system ,Epithelium ,Proliferating cell nuclear antigen ,medicine.anatomical_structure ,Cell culture ,Immunology ,Cancer research ,biology.protein ,Wound healing ,HeLa Cells - Abstract
Background Human rhinoviruses (RV), the most common triggers of acute asthma exacerbations, are considered not cytotoxic to the bronchial epithelium. Recent observations, however, have questioned this knowledge. The aim of this study was to evaluate the ability of RV to induce epithelial cytotoxicity and affect epithelial repair in-vitro. Methods Monolayers of BEAS-2B bronchial epithelial cells, seeded at different densities were exposed to RV serotypes 1b, 5, 7, 9, 14, 16. Cytotoxicity was assessed chromatometrically. Epithelial monolayers were mechanically wounded, exposed or not to RV and the repopulation of the damaged area was assessed by image analysis. Finally epithelial cell proliferation was assessed by quantitation of proliferating cell nuclear antigen (PCNA) by flow cytometry. Results RV1b, RV5, RV7, RV14 and RV16 were able to induce considerable epithelial cytotoxicity, more pronounced in less dense cultures, in a cell-density and dose-dependent manner. RV9 was not cytotoxic. Furthermore, RV infection diminished the self-repair capacity of bronchial epithelial cells and reduced cell proliferation. Conclusion RV-induced epithelial cytotoxicity may become considerable in already compromised epithelium, such as in the case of asthma. The RV-induced impairment on epithelial proliferation and self-repair capacity may contribute to the development of airway remodeling.
- Published
- 2005
22. Treatment of Chronic Idiopathic Thrombocytopenic Purpura
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Andreas Constantopoulos, Stavros Haidas, Angelika Mitsika, S Aronis, and Helen Platokouki
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medicine.medical_specialty ,Oncology ,business.industry ,Pediatrics, Perinatology and Child Health ,Chronic idiopathic thrombocytopenic purpura ,Medicine ,Hematology ,business ,Dermatology - Published
- 1995
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23. Decrease of ex vivo expression of costimulation molecules during virus-induced asthma exacerbations in peripheral blood mononuclear cells of atopic asthmatic children
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M. Xatzipsalti, Photini Saxoni-Papageorgiou, Apostolos Bossios, Nikolaos G. Papadopoulos, E. Manousakis, Dimitrios Gourgiotis, Andreas Constantopoulos, and Fotis Psarros
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Asthmatic children ,Asthma exacerbations ,business.industry ,Immunology ,Immunology and Allergy ,Medicine ,business ,Peripheral blood mononuclear cell ,Ex vivo ,Virus - Published
- 2003
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24. Serum Pepsinogen I(Pgi) in Children With Gastritis 64
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E Loutsi, C Barbati, A Charissiadou, Christos Kattamis, Joanna Panayiotou, Andreas Constantopoulos, and E Roma
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medicine.medical_specialty ,Pathology ,biology ,business.industry ,Histology ,Helicobacter pylori ,biology.organism_classification ,Gastroenterology ,Asymptomatic ,Internal medicine ,Pediatrics, Perinatology and Child Health ,medicine ,biology.protein ,Upper gastrointestinal ,Analysis of variance ,Serum pepsinogen ,medicine.symptom ,Gastritis ,Antibody ,business - Abstract
Gastritis, associated or not by Helicobacter Pylori (HP) infection, consists a common cause of upper gastrointestinal symptomatology in children. The aim of the present study was to investigate a possible correlation of serum PGI levels to gastritis in children. The studv comprised 98 symptomatic and 41 asymptomatic children divided in 5 groups. A: 54(10.5±2yrs) with HP gastritis, B: 13(11±1.2yrs) after eradication of HP, C: 25 (10±2.2yrs) with gastritis without HP, D: 19 (9.4±2yrs) with normal gastric biopsy and E: 41 asymptomatic (9.1±1.5yrs). Children of groups A, B, C, D underwent upper endoscopy and HP detection by histology, CLO test and serum antibodies to HP. Serum PGI was estimated once in all groups, while it was repeated in group B. Statistics were performed by analysis of variance. Results are as follow:Table
- Published
- 1997
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25. Prevalence of β0and β+Thalassemia Genes in Greek Children with Homozygous β-Thalassemia
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Andreas Constantopoulos, Katerina Karambula, A. Metaxotou-Mavromati, Vasilios Ladis, and Christos Kattamis
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medicine.medical_specialty ,Genotype ,Thalassemia ,Clinical Biochemistry ,Biology ,Gene Frequency ,Internal medicine ,medicine ,Humans ,Child ,Gene ,Homozygous beta thalassemia ,Fetal Hemoglobin ,Genetics (clinical) ,Genetics ,Greece ,Double dose ,Homozygote ,Biochemistry (medical) ,Infant, Newborn ,Infant ,Beta thalassemia ,Hemoglobin A ,Hematology ,Chromatography, Ion Exchange ,medicine.disease ,Endocrinology ,Child, Preschool - Abstract
In an attempt to estimate the prevalence of β0 and β+thalassemia genes in Greece chromatographic analysis of hemoglobins was performed in 30 children with homozygous β-thalassemia prior to any transfusion. In 13 (43%) no HbA was detected, suggesting the presence of β0 gene in the homozygous state (β0/β thal). In the remaining 17, HbA showed a bimodal distribution with values ranging from 4–36%. The detection of HbA suggests the presence of β+ gene, while the bimodal distribution could be explained by the assumption that the β+ gene in single dose and in combination with β0 gene (β0/β+ thai) results in the production of small amounts of HbA ranging from 4–11%, (first curve), while in double dose (β+/β+ thal), in the production of higher amounts of HbA ranging from 24–36% (second curve). The β0/β+ thai was observed in 11 (37%), and the β+/β+ thai in 6(20%). It is concluded that both β0 and β+genes are common in Greece and chromatographic analysis helps to determine the genotype of patients with homozygous β...
- Published
- 1978
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26. Augmentation of uridine diphosphate glucuronyltransferase activity in rat liver by adenosine 3′,5′-monophosphate
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Nicholas Matsaniotis and Andreas Constantopoulos
- Subjects
medicine.medical_specialty ,Bilirubin ,Stimulation ,Glucagon ,chemistry.chemical_compound ,Mediator ,Internal medicine ,medicine ,Animals ,Nucleotide ,Glucuronosyltransferase ,chemistry.chemical_classification ,Hepatology ,biology ,Gastroenterology ,Adenosine ,Adenosine Monophosphate ,Stimulation, Chemical ,Enzyme assay ,Rats ,Enzyme Activation ,Uridine diphosphate ,Endocrinology ,Bucladesine ,Liver ,chemistry ,biology.protein ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
The role of cyclic adenosine 3′,5′-monophosphate (cAMP) in the regulation of rat liver bilirubin uridine diphosphate glucuronyltransferase (UDP-GT) was studied. Augmentation of UDP-GT activity was obtained by cAMP, but not by 3′-AMP. A single administration of glucagon initiated a rapid but limited increase in enzyme activity, which reached a maximum after 2 hr. Similar augmentation of the hepatic enzyme was produced by injection of N 6 ,O 2 -dibutyryl cAMP. The nucleotide is the mediator for UDP-GT augmentation by glucagon. The injection of glucagon led within 20 min to a 40-fold increase in the concentration of cAMP. The augmentation of UDP-GT activity by glucagon or dibutyryl cAMP was fully inhibited by actinomycin D. A second stimulation of liver by glucagon or dibutyryl cAMP 4 hr after the first injection, produced a new increase of UDP-GT activity.
- Published
- 1978
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27. Effect of Ascorbic Acid on Guinea Pig Adrenal Adenylate Cyclase Activity and Plasma Cortisol
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Andreas Constantopoulos, Basil Litsios, and Nicholas L. Doulas
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Male ,medicine.medical_specialty ,Hydrocortisone ,Guinea Pigs ,Medicine (miscellaneous) ,Adenylate kinase ,Ascorbic Acid ,Cyclase ,Guinea pig ,chemistry.chemical_compound ,Basal (phylogenetics) ,In vivo ,Internal medicine ,Adrenal Glands ,Sodium fluoride ,medicine ,Animals ,Nutrition and Dietetics ,Ascorbic acid ,surgical procedures, operative ,Endocrinology ,chemistry ,Ascorbic Acid Deficiency ,Sodium Fluoride ,Cyclase activity ,Adenylyl Cyclases - Abstract
Intra-adrenal ascorbic acid (AsA) concentrations exert a braking or modulating effect upon steroid release. Because changes in steroidogenesis are mediated through alterations in adenylate cyclase activity (ACL), the effect of varied AsA plasma concentrations on guinea pig adrenal ACL activity and plasma cortisol was studied. Forty-two male guinea pigs were randomly allocated to the following seven groups: controls, scorbutic, and groups given 0.1, 5, 10, 20 or 100 mg ascorbic acid/100 g body weight, respectively. Scorbutic animals had very low levels of AsA in comparison to control animals. Plasma AsA levels increased as AsA dose increased. The levels of AsA in the group given 0.1 mg AsA were higher than in controls. Basal adenylate cyclase activity did not vary significantly among animal groups. In contrast, values for NaF-stimulated ACL activity showed a progressive decrease with increasing AsA doses. A highly significant correlation was found between decreasing ACL activity and increasing plasma AsA concentrations. On the other hand, NaF-responsive ACL activity was higher in scorbutic animals than in any other group. Higher mean cortisol values were found in the scorbutic group than in the controls, correlating with high levels of NAF-stimulated ACL activity. Higher mean cortisol values were also found in the group given 0.1 mg AsA although ACL activity in this group was not affected. This finding, coupled with reduced ACL activity in these groups, is consistent with the inhibitory effect of a megadose of AsA on production of cortisol from the adrenal. The above data may suggest that differing plasma concentrations of AsA regulate in vivo steroidogenesis by altering the activity of the membrane-bound enzyme adenylate cyclase.
- Published
- 1987
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28. The characteristics, isolation and synthesis of the phagocytosis stimulating peptide tuftsin
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Paul S. Satoh, Kenji Nishioka, Andreas Constantopoulos, and Victor A. Najjar
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Threonine ,Chemical Phenomena ,Formates ,Proline ,Arginine ,Butanols ,Phagocytosis ,Guinea Pigs ,Lysine ,Tuftsin ,Biophysics ,Peptide ,Biology ,Biochemistry ,Mice ,chemistry.chemical_compound ,Dogs ,Cricetinae ,Leukocytes ,medicine ,Animals ,Humans ,Trypsin ,Amino Acid Sequence ,Molecular Biology ,Peptide sequence ,Dansyl Compounds ,chemistry.chemical_classification ,Macrophages ,Cell Biology ,Chromatography, Ion Exchange ,Chemistry ,chemistry ,Chromatography, Gel ,Chromatography, Thin Layer ,Rabbits ,gamma-Globulins ,Peptides ,medicine.drug - Abstract
Summary The phagocytosis stimulating peptide present in γ-globulin has been isolated and its amino acid sequence shown to be L-threonyl-L-lysyl-L-prolyl-L-arginine. It was synthesized by the solid phase technic.
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- 1972
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29. The activation of adenylate cyclase: II. The postulated presence of (A) adenylate cyclase in a phospho (inhibited) form (B) a dephospho (activated) form with a cyclic adenylate stimulated membrane protein kinase
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Andreas Constantopoulos and Victor A. Najjar
- Subjects
Blood Platelets ,Time Factors ,Biophysics ,Adenylate kinase ,Tritium ,Biochemistry ,Cyclase ,Fluorides ,Cytosol ,Dogs ,Cyclic AMP ,Leukocytes ,Animals ,Protein kinase A ,Molecular Biology ,Kinase ,Chemistry ,Cell Membrane ,Phosphotransferases ,Phosphorus Isotopes ,Cell Biology ,Enzyme Activation ,Kinetics ,Membrane ,Membrane protein ,Prostaglandins ,Phosphorylation ,Rabbits ,Protein Kinases ,Cyclase activity ,Adenylyl Cyclases ,Subcellular Fractions - Abstract
Membrane adenylate cyclase (AC) from polymorphonuclear (PMN) leucocytes and platelet membranes are activated several fold by fluoride and prostaglandin E1 (PGE1) respectively. Incubation of such activated membranes in a phosphorylating system inhibits cyclase activity. The inhibition can now be relieved by further treatment with fluoride and PGE1 respectively. These findings suggest that AC exists in an inhibited phospho- and activated dephospho-form. This is supported by the finding that membrane preparations from both sources contain a cyclic adenylate (cAMP) stimulated protein kinase and points to the existence of an adequate membrane phosphorylating system.
- Published
- 1973
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30. The Requirement for Membrane Sialic Acid in the Stimulation of Phagocytosis by the Natural Tetrapeptide, Tuftsin
- Author
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Andreas Constantopoulos and Victor A. Najjar
- Subjects
chemistry.chemical_classification ,biology ,Phagocyte ,Tetrapeptide ,Phagocytosis ,Tuftsin ,Stimulation ,Cell Biology ,Biochemistry ,Microbiology ,Sialic acid ,chemistry.chemical_compound ,Enzyme ,medicine.anatomical_structure ,chemistry ,biology.protein ,medicine ,Molecular Biology ,Neuraminidase - Abstract
The presence of sialic acid on the polymorphonuclear (PMN) phagocyte is necessary for maximal stimulation of its phagocytic activity by the tetrapeptide, tuftsin, Thr-Lys-Pro-Arg. Treatment of polymorphonuclear cells with bacterial neuraminidases, purified by affinity chromatography, completely abolishes stimulation of phagocytic activity by free tuftsin or by tuftsin bound to the carrier leukokinin molecule. These enzymes cleave sialic acid at both 2-3' and 2-6' glycosidic bonds. By contrast, treatment of cells with influenza virus neuraminidase, which cleaves predominantly the 2-3' linkage, reduces the tuftsin effect by approximately 50%. Enzyme-treated cells remain viable and capable of phagocytosis. Cells treated with any of the neuraminidases and cells of the untreated controls show comparable levels of phagocytosis in the absence of tuftsin. While membrane sialic acid is necessary for stimulation of phagocytosis, it may function only as a binding site for the three positively charged residues of the tetrapeptide. Neuraminidases from Vibrio cholerae or Clostridium perfringens, in excess amounts, released in 2 hours a maximum of about 135 million molecules of sialic acid per polymorphonuclear cell. Under similar conditions, treatment with influenza virus released approximately 30 million molecules per cell.
- Published
- 1973
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31. TUFTSIN DEFICIENCY SYNDROME A Report of Two New Cases
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Andreas Constantopoulos and Victor A. Najja
- Subjects
Adult ,Male ,Immunodiffusion ,Pathology ,medicine.medical_specialty ,Recurrent infections ,Adolescent ,Phagocytosis ,Liver Abscess ,Tuftsin ,medicine.disease_cause ,chemistry.chemical_compound ,Pneumonia, Staphylococcal ,medicine ,Humans ,Skin Diseases, Infectious ,Child ,Immunoglobulin Fragments ,business.industry ,General Medicine ,Staphylococcal Infections ,medicine.disease ,Tuftsin Deficiency ,Pneumonia ,chemistry ,Staphylococcus aureus ,Child, Preschool ,Pediatrics, Perinatology and Child Health ,Immunology ,Female ,gamma-Globulins ,business ,Skin lesion ,Oligopeptides - Abstract
SUMMARY Two families with deficiency in the phagocytosis stimulating peptide, tuftsin, are reported. Both cases gave a history of recurrent infections. In the first case, (D. I.) all infection involved only external surfaces. The second patient (W. M.) showed involvement of internal organs with septicimia pneumonia and liver abcess in addition to skin lesions. In both cases, Staphylococcus aureus was the infecting organism.
- Published
- 1973
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32. Demography of adolescent health care delivery and training in Europe
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Pavel Kabicek, Ethem Erginöz, Mehmet Vural, Oya Ercan, Andreas Constantopoulos, Mujgan Alikasifoglu, Jan Janda, Armido Rubino, and Özdemir İlter
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medicine.medical_specialty ,Adolescent ,Context (language use) ,Subspecialty ,Pediatrics ,Adolescent medicine ,Adolescent Medicine ,Nursing ,Surveys and Questionnaires ,medicine ,Humans ,Outpatient clinic ,Pediatrics, Perinatology, and Child Health ,Practice Patterns, Physicians' ,Demography ,Education, Medical ,business.industry ,Public health ,Mortality rate ,Age Factors ,Physicians, Family ,Europe ,Gross national income ,Adolescent Health Services ,Family medicine ,Pediatrics, Perinatology and Child Health ,Family Practice ,business ,Delivery of Health Care ,Adolescent health - Abstract
We aimed to determine the status of and factors associated with adolescent health care delivery and training in Europe on behalf of the European Paediatric Association—UNEPSA. A questionnaire was mailed to the presidents of 48 national paediatric societies in Europe. For statistical analyses, non-parametric tests were used as appropriate. Six of the countries had a paediatric (PSPCA), 14 had a combined and nine had a general practitioner/family doctor system for the primary care of adolescents (GP/FDSA). Paediatricians served children 17 years of age or older in 15 and 17, up to 16 years of age in three and six, and up to 14 years of age in six and six countries in outpatient and inpatient settings, respectively. Fifteen and 18 of the countries had some kind of special inpatient wards and outpatient clinics for adolescents, respectively. Twenty-eight of the countries had some kind of national/governmental screening or/and preventive health programmes for adolescents. In countries with a PSPCA, the gross national income (GNI) per capita was significantly lower than in those with a GP/FDSA, and the mean upper age limit of adolescents was significantly higher than in those with the other systems. In the eastern part of Europe, the mortality rate of 10–14 year olds was significantly higher than that in the western part (p=0.008). Training in adolescent medicine was offered in pre-graduate education in 14 countries in the paediatric curriculum and in the context of paediatric residency and GP/family physician residency programmes in 18 and nine countries, respectively. Adolescent medicine was reported as a recognised subspecialty in 15 countries and as a certified subspecialty of paediatrics in one country. In countries with a PSPCA, paediatric residents were more likely to be educated in adolescent medicine than paediatric residents in countries with a GP/FDSA. The results of the present study show that there is a need for the reconstruction and standardisation of adolescent health care delivery and training in European countries. The European Paediatric Association—UNEPSA could play a key role in the implementation of the proposals suggested in this paper.
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33. Congenital Tuftsin Deficiency
- Author
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Andreas Constantopoulos
- Subjects
Male ,Adolescent ,Tuftsin ,Mutant ,Peptide ,Infections ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,History and Philosophy of Science ,Medicine ,Humans ,Respiratory system ,Skin Diseases, Infectious ,Child ,Respiratory Tract Infections ,chemistry.chemical_classification ,Tetrapeptide ,business.industry ,General Neuroscience ,Infant, Newborn ,Infant ,Tuftsin Deficiency ,chemistry ,Child, Preschool ,Humoral immunity ,Immunology ,Female ,Lymph ,Lymph Nodes ,gamma-Globulins ,business ,Infant, Premature - Abstract
The serum tuftsin activity in four different pediatric groups has been studied: (a) 20 premature infants, (b) 20 full-term infants, (c) 20 normal children (controls), and (d) 5 patients with recurrent and severe infections of the respiratory system, skin, and lymph nodes. The normal children as well as the premature and full-term infants had normal tuftsin activity. Tuftsin activity in the serum of the 5 patients in group (d) was absent. Cellular and humoral immunity in these patients was normal. All patients have been shown to have a mutant peptide that is strongly inhibitory to the normal tetrapeptide tuftsin. The clinical response of these patients to gamma-globulin was excellent.
- Published
- 1983
34. Breast milk jaundice; the role of lipoprotein lipase and the free fatty acids
- Author
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Andreas Constantopoulos, J. Messaritakis, and N. Matsaniotis
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medicine.medical_specialty ,Time Factors ,Fatty Acids, Nonesterified ,Internal medicine ,medicine ,Humans ,chemistry.chemical_classification ,Lipoprotein lipase ,Prolonged neonatal jaundice ,Milk, Human ,business.industry ,Infant, Newborn ,Breast Milk Jaundice ,Fatty acid ,Jaundice ,Normal limit ,Jaundice, Neonatal ,Lipoprotein Lipase ,Endocrinology ,Breast Feeding ,chemistry ,Pediatrics, Perinatology and Child Health ,Female ,medicine.symptom ,business ,Breast feeding ,Lipoprotein lipase activity - Abstract
Lipoprotein lipase activity and free fatty acid concentrations were measured in samples of milk collected from mothers of infants without and with prolonged neonatal jaundice. The lipoprotein lipase and free fatty acid values in the milk from mothers of infants without jaundice were found to increase with the duration of breast-feeding until the 12th post-partum day, and then to fall to the original levels. In the group of mothers with jaundiced infants both lipoprotein lipase and free fatty acid values were found within normal limits when measured between 15th and 37th days post-partum. These findings indicate that increased values of lipoprotein lipase and free fatty acids in the milk are not responsible for the development of breast-milk jaundice.
- Published
- 1980
35. Defective phagocytosis due to tuftsin deficiency in splenectomized subjects
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Thomas H. Necheles, Jay B. Wish, Andreas Constantopoulos, Leo L. Stolbach, and Victor A. Najjar
- Subjects
Adult ,medicine.medical_specialty ,Phagocytosis ,Chronic lymphocytic leukemia ,Tuftsin ,Spleen ,Anemia, Sickle Cell ,Spherocytosis, Hereditary ,chemistry.chemical_compound ,Defective phagocytosis ,hemic and lymphatic diseases ,Internal medicine ,medicine ,Humans ,Immunoglobulin Fragments ,Gaucher Disease ,Hyperplasia ,business.industry ,Chronic granulocytic leukemia ,Tuftsin Deficiency ,medicine.disease ,Hodgkin Disease ,Leukemia, Lymphoid ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Leukemia, Myeloid ,Pediatrics, Perinatology and Child Health ,Immunology ,Splenectomy ,Thalassemia ,Wounds and Injuries ,Lymph Nodes ,business ,Oligopeptides - Abstract
The activity of the phagocytosis stimulating peptide, tuftsin, was decreased in the serum of 18 of 23 splenectomized patients. Three of the splenectomized subjects with normal or near-normal tuftsin activity had had traumatic rupture of the spleen. Decreased tuftsin activity was also demonstrated in three patients with sickle-cell disease and in two adults with chronic granulocytic leukemia. Intermediate activity was measured in three patients with chronic lymphocytic leukemia and one patient with β-thalassemia.
- Published
- 1973
36. The physiological role of the lymphoid system. The binding of autologous thrombophilic gamma-globulin to human platelets
- Author
-
Victor A. Najjar and Andreas Constantopoulos
- Subjects
Blood Platelets ,Immunodiffusion ,Sucrose ,Binding Sites ,Goats ,Receptors, Drug ,Osmolar Concentration ,Fluorescent Antibody Technique ,Biology ,Chromatography, Ion Exchange ,Fluoresceins ,Biochemistry ,Lymphatic system ,Sucrose solution ,Immunology ,Isotonic ,Animals ,Humans ,Platelet ,Electrophoresis, Paper ,Spectrophotometry, Ultraviolet ,gamma-Globulins ,Protein Binding - Abstract
Blood thrombocytes are shown to bind specific fractions of autologous γ-globulin in isotonic low-ionic-strength sucrose solution. Thrombocytes in freshly drawn blood that were prepared in their plasma not exposed to sucrose solution were found coated with the same specific thrombophilic γ-globulin fractions. Judging by the active physiological role of erythrophilic and leucophilic γ-globulin, it is proposed that thrombophilie γ-globulin may have an equally important role, the nature of which is yet to be determined.
- Published
- 1974
37. The activation of adenylate cyclase. I. A postulated mechanism for fluoride and hormone activation of adenylate cyclase
- Author
-
Victor A. Najjar and Andreas Constantopoulos
- Subjects
Blood Platelets ,Time Factors ,Clinical Biochemistry ,Adenylate kinase ,Cyclase ,Models, Biological ,chemistry.chemical_compound ,Fluorides ,Leukocytes ,Animals ,heterocyclic compounds ,Molecular Biology ,chemistry.chemical_classification ,Binding Sites ,Mechanism (biology) ,Cell Membrane ,Cell Biology ,General Medicine ,Enzyme Activation ,Kinetics ,Enzyme ,chemistry ,Biochemistry ,Prostaglandins ,Phosphorylation ,Rabbits ,Fluoride ,Phosphorus Radioisotopes ,Protein Kinases ,Hormone ,Adenylyl Cyclases ,Protein Binding - Abstract
Two postulated mechanisms for the activation of adenylate cyclase are presented. Both require that the enzyme exist in an inhibited phosphorylated form and an activated dephosphorylated form.
- Published
- 1973
38. The occurrence of fluoride stimulated membrane phosphoprotein phosphatase
- Author
-
John F.X. Judge, Porter P. Layne, Richard Rauner, Victor A. Najjar, and Andreas Constantopoulos
- Subjects
Blood Platelets ,Phosphoric monoester hydrolases ,Time Factors ,Biophysics ,Endogeny ,Biochemistry ,Cell membrane ,chemistry.chemical_compound ,Enzyme activator ,Fluorides ,medicine ,Leukocytes ,Animals ,Molecular Biology ,Peritoneal Cavity ,chemistry.chemical_classification ,fungi ,Cell Membrane ,Glucosephosphates ,Phosphorus Isotopes ,Cell Biology ,Phosphoproteins ,Molecular biology ,Phosphoric Monoester Hydrolases ,Enzyme Activation ,medicine.anatomical_structure ,Enzyme ,Membrane ,chemistry ,Phosphoglucomutase ,Prostaglandins ,Rabbits ,Fluoride - Abstract
Membrane preparations from rabbit peritoneal granulocytes and dog blood platelets possess an active phosphoprotein phosphatase. The enzyme is stimulated by fluoride and to a lesser extent by prostaglandin E1 (PGE1). It dephosphorylates 32P labeled, catalytically active phosphoglucomutase (PGM) and labeled endogenous membranes to yield, in both cases, inorganic phosphate. It is inactive towards denatured PGM, denatured endogenous membranes and thymus histone labeled with 32P.
- Published
- 1973
39. The chemical synthesis of the phagocytosis-stimulating tetrapeptide tuftsin (Thr-Lys-Pro-Arg) and its biological properties
- Author
-
Paul S. Satoh, Andreas Constantopoulos, Kenji Nishioka, and Victor A. Najjar
- Subjects
Erythrocytes ,Stereochemistry ,Phagocytosis ,Tuftsin ,Biochemistry, Genetics and Molecular Biology (miscellaneous) ,Chemical synthesis ,Pentapeptide repeat ,chemistry.chemical_compound ,Structure-Activity Relationship ,Dogs ,Biological property ,Leukocytes ,Animals ,Amino Acid Sequence ,Amino Acids ,Chromatography ,Autoanalysis ,Tetrapeptide ,Natural compound ,Cell migration ,Chromatography, Ion Exchange ,Biochemistry ,chemistry ,Chromatography, Thin Layer ,Oligopeptides - Abstract
Tuftsin, the phagocytosis-stimulating tetrapeptide Thr-Lys-Pro-Arg, has been synthesized using the Merrifield solid-phase method. A strongly inhibitory analog Thr-Lys-Pro-Pro-Arg was similarly synthesized. Synthetic tuftsin has all the properties of the natural compound, physical, chemical and biological. It stimulates phagocytosis and cell migration with similar specific activities. Both properties are inhibited by the pentapeptide analog. Thr-Lys-Pro and Lys-Pro-Arg are inactive at comparable dosage.
- Published
- 1973
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