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The pozzolanic effect of perlite powder (PP) added to concrete can be determined quantitatively with strength indices: specific strength ratio (R), index of specific strength (K), and contribution percentage of pozzolanic effect to strength (P). Besides compressive strength, these indices indicate that perlite powder has a high pozzolanic effect and is an active mineral admixture (MA) for concrete. [Copyright &y& Elsevier]

Deals with the magnetic media for 10 gigabyte per square inch hard disk storage. Recording format and magnetic requirements; Status of media development as of April 1996; Discussion of media structure preparation approach.

Presents a study that investigated substrate bias effects on composition and coercivity of cobalt chromium tantalum/chromium thin films on canasite and glass. Details of the experiment; Results and discussion; Conclusions.

Objective: To evaluate the relationship between antenatal pelvic floor biometry and levator ani muscle (LAM) injury in Chinese women.Methods: Three-dimensional transperineal ultrasound was performed in nulliparous Chinese women with a singleton pregnancy at 9-12 weeks, 26-28 weeks and 36-38 weeks of gestation and again at 12 months after delivery. Hiatal anteroposterior (AP) diameter, transverse diameter and area were measured on the antenatal ultrasound volumes obtained at rest, on Valsalva maneuver and during pelvic floor muscle contraction (PFMC). LAM injury was evaluated using ultrasound volumes obtained during PFMC at 12 months after delivery.Results: In total, 328 women completed the study. At 12 months after delivery, 38 (14.8% of those who delivered vaginally) women had LAM injury; 28 were unilateral (14 right- and 14 left-sided) and 10 were bilateral. In all three trimesters there was smaller hiatal AP diameter and hiatal area in women with LAM injury when compared with women without injury. On multivariable analysis of the three factors, hiatal AP diameter at rest, hiatal area at rest and operative vaginal delivery, only hiatal AP diameter at rest in all three trimesters was an independent factor of LAM injury. A larger hiatal AP diameter at rest in the first, second and third trimesters reduced the likelihood of LAM injury with odds ratios of 0.21, 0.15 and 0.21, respectively.Conclusions: A smaller antenatal hiatal AP diameter at rest is a risk factor for LAM injury. The hiatal AP diameter is relatively simple to measure and the error in measurement is relatively small. A prospective study to confirm this relationship and to explore whether this measurement, performed in the midsagittal plane, is repeatable should be performed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

ABSTRACT Objectives To evaluate pelvic floor biometry in Chinese women 1 year following childbirth and to explore factors that affect it. Methods Translabial ultrasound examination was performed at rest, on Valsalva maneuver ( VM) and on pelvic floor muscle contraction ( PFMC) in the first, second and third trimesters of pregnancy and at 8 weeks, 6 months and 12 months after delivery in a cohort of women delivering at term their first child. Offline analysis was undertaken to measure the position of the bladder neck, cervix, anorectal junction and hiatal dimensions at each posture and at each visit, and to detect levator ani muscle ( LAM) injury on PFMC 8 weeks and 12 months after delivery. Results were analyzed according to mode of delivery. Results We recruited 442 women, of whom 328 (74.2%) completed the study; there was LAM injury in 48 women at 8 weeks and in only 38 women at 12 months. When comparing first-trimester biometry to that at 12 months after delivery, the bladder neck was more distal on VM and bladder neck displacement was increased, and the cervix was lower at rest and on VM in the vaginal delivery group. In the Cesarean section group, bladder neck and anorectal junction were more distal on VM, the cervix was lower at rest, on VM and on PFMC, and the hiatal area was increased on VM. There was a greater increase in hiatal area after vaginal delivery. Overall, 34.8% had irreversible hiatal distension (> 20% increase in hiatal area after delivery as compared to first trimester). LAM injury was significantly associated with irreversible hiatal distension (odds ratios, 5.2-9.5 at different postures). Conclusions Pregnancy beyond 35 weeks of gestation has an effect on the pelvic floor of Chinese women, irrespective of mode of delivery. The pelvic organs remain more mobile after delivery when compared to in the first trimester, and there is no clear difference between the findings observed following vaginal delivery or Cesarean section, except in hiatal distension, which is greater after vaginal delivery. LAM injury is the factor most strongly associated with irreversible hiatal distension. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Objectives To assess the prevalence of levator ani muscle injury in Chinese women after their first delivery and investigate associated factors. Methods A prospective observational study was conducted involving Chinese nulliparous women recruited in the first trimester of pregnancy. Translabial ultrasound was performed at 35-38 weeks' gestation and 8 weeks postpartum and three-dimensional volume datasets were obtained. Offline analysis to detect levator ani muscle injury was performed by investigators blinded to the delivery details. Results 339 women, with a mean age of 30.6 ± 3.9 years, completed the study. Overall, 201 (59.3%) had a spontaneous vaginal delivery, 62 (18.3%) an operative vaginal delivery (48 ventouse extraction and 14 forceps delivery), 14 (4.1%) an elective Cesarean section and 62 (18.3%) an emergency Cesarean section. No levator ani muscle injury was detected in any woman antenatally. After vaginal delivery, 57 (21.7% (95% CI, 16.7-26.7%)) women had levator ani muscle injury. The rates of injury for spontaneous vaginal delivery, ventouse extraction and forceps delivery were 15.4%, 33.3% and 71.4%, respectively. There was no levator ani muscle injury in the Cesarean section groups. Logistic regression analysis showed that only operative vaginal delivery (odds ratio, 3.09) was associated with an independent increase in the likelihood of levator ani muscle injury. Intrapartum epidural analgesics, duration of second stage of labor and infant birth weight were not independently associated with levator ani muscle injury. Conclusions The prevalence of levator ani muscle injury in Chinese women after their first vaginal delivery was 21.7% (95% CI, 16.7-26.7%). Operative vaginal delivery was found to increase the likelihood of women suffering such injury. A longer follow-up of these women and future studies on the effects of episiotomy are proposed. Copyright © 2012 ISUOG. Published by John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

We studied the isoprostane level, a well-recognised biomarker of oxidative stress, from women with uterine prolapse and age-matched female controls without prolapse. Cardinal ligament-derived fibroblasts explanted from women with prolapse showed a significant increased level of isoprostane production ( P < 0.05) compared with those derived from controls. This concurs with elevated urinary isoprostane levels identified among women with prolapse ( P < 0.001) compared with controls. In addition, the matrix metalloproteinase 2 mRNA was significantly increased ( P= 0.004) among women with uterine prolapse. Parallel findings of increased isoprostane in cardinal ligament and urine sample among women with prolapse suggest that oxidative stress might be involved in the development of uterine prolapse. [ABSTRACT FROM AUTHOR]

A thermal system is developed to rapidly characterize the linewidth sensitivity of advanced resists to process temperature variations in the photolithographic manufacturing sequence. This thermal array consists of a 7×7 grid of individually programmable heating zones distributed within a thermal cycling apparatus. It is used to improve the quality and quantity of data for determining the optimal thermal conditions by effectively producing equivalent operating conditions besides the spatially controlled temperature. The system is demonstrated for the optimization of the post-apply and post-exposure thermal-processing conditions for chemically amplified photoresists used in the fabrication of quartz photomasks . [ABSTRACT FROM AUTHOR]

Introduction: The Hospital Authority of Hong Kong Special Administrative Region established a coronavirus disease 2019 (COVID-19) temporary test centre at the AsiaWorld-Expo from March 2020 to April 2020, which allowed high-risk individuals to undergo early assessment of potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. This study reviewed the characteristics and outcomes of individuals who attended the centre for COVID-19 testing., Methods: This retrospective cross-sectional study collected epidemiological and clinical data. The primary outcome was a positive or negative SARS-CoV-2 test result, according to reverse transcription polymerase chain reaction analyses of pooled nasopharyngeal and throat swabs collected at the centre. The relationships of clinical characteristics with SARS-CoV-2 positive test results were assessed by multivariable binary logistic regression., Results: Of 1258 attendees included in the analysis, 86 individuals tested positive for SARS-CoV-2 infection (positivity rate=6.84%; 95% confidence interval [CI]=5.57%-8.37%). Of these 86 individuals, 40 (46.5%) were aged 15 to 24 years and 81 (94.2%) had a history of recent travel. Symptoms were reported by 86.0% and 96.3% of individuals with positive and negative test results, respectively. The clinical characteristics most strongly associated with a positive test result were anosmia (adjusted odds ratio [OR adj ]=8.30; 95% CI=1.12-127.09) and fever OR adj =1.32; 95% CI=1.02-3.28)., Conclusion: The temporary test centre successfully helped identify individuals with COVID-19 who exhibited mild disease symptoms. Healthcare providers should carefully consider the epidemiological and clinical characteristics of COVID-19 to arrange early testing to reduce community spread., Competing Interests: All authors have disclosed no conflicts of interest.

Introduction: Obstetric anal sphincter injuries (OASIS) may be underdetected in primiparous women. This study evaluated the prevalence of OASIS in primiparous women after normal vaginal delivery or instrumental delivery using endoanal ultrasound (US) during postnatal follow-up., Methods: This study retrospectively analysed endoanal US data collected during postnatal follow-up (6-12 months after vaginal delivery) at a tertiary hospital in Hong Kong. Offline analysis to determine the prevalence of OASIS was performed by two researchers who were blinded to the clinical diagnosis. Symptoms of faecal and flatal incontinence were assessed with the Pelvic Floor Distress Inventory., Results: Of 542 women included in the study, 205 had normal vaginal delivery and 337 had instrumental delivery. The prevalence of OASIS detected by endoanal US was 7.8% (95% confidence interval [CI]=4.1%-11.5%) in the normal vaginal delivery group and 5.6% (95% CI=3.1%-8.1%) in the instrumental delivery group. Overall, 82.9% of women with OASIS on endoanal US did not show clinical signs of OASIS. Birth weight was significantly higher in the OASIS group (P=0.012). At 6 to 12 months after delivery, 5.5% of women reported faecal incontinence and 17.9% reported flatal incontinence, but OASIS was not associated with these symptoms., Conclusions: Additional training for midwives and doctors may improve OASIS detection., Competing Interests: As an editor of the journal, JPW Chung was not involved in the peer review process. Other authors have disclosed no conflicts of interest.

Introduction and Hypothesis: To evaluate the effect of levator ani muscle (LAM) injury on pelvic floor disorders and health-related quality of life in Chinese primiparous women during the first year after delivery., Methods: At 8 weeks and 12 months after delivery, 328 women were assessed for symptoms of pelvic floor disorders and quality of life using the standardised questionnaire, POP-Q; and translabial ultrasound to detect LAM injury. Descriptive analysis, independent sample t test, non-parametric testing, Chi-squared test and two-sided Fisher's exact test were used., Results: At 8 weeks after delivery, 48 (19.0% [95% CI, 14.2-23.8%]) women with vaginal delivery had LAM injury; 38 women (79.2%) had persistent LAM injury at 12 months. At 8 weeks, LAM injury was associated with prolapse symptoms, descent at Pelvic Organ Prolapse Quantification (POP-Q) Aa and Ba points and a higher Pelvic Organ Prolapse Distress Inventory (POPDI) general and Urinary Distress Inventory (UDI) Obstructive subscale score. At 12 months, it was not associated with prolapse symptoms, Pelvic Floor Distress Inventory (PFDI) or Pelvic Floor Impact Questionnaire (PFIQ). There was also no association between stress urinary incontinence (SUI), urge urinary incontinence (UUI), mixed urinary incontinence (UI), faecal incontinence (FI) with LAM injury at both time points., Conclusions: Seventy-nine per cent of women who had LAM injury at 8 weeks after vaginal delivery had persistent LAM injury at 12 months. LAM injury was associated with prolapse symptoms, lower POP-Q Aa and Ba points at 8 weeks after delivery and a higher POPDI general and UDI Obstructive subscale scoring. However, we are not able to confirm the association between LAM injury and SUI, UUI, mixed UI, FI at 8 weeks or 12 months after delivery; or prolapse symptoms, PFDI or PFIQ scores at 12 months after delivery.

Objective: To assess pelvic floor biometry during pregnancy and the correlation with symptoms of pelvic floor disorders in women., Design: A prospective observational study., Setting: Antenatal clinic between August 2009 and May 2011., Population: Nulliparous women in their first pregnancy., Methods: Pelvic floor was assessed by translabial ultrasound and symptoms of pelvic floor disorders were explored with a standardised questionnaire at each trimester., Main Outcome Measures: Pelvic floor biometry during pregnancy., Results: A total of 405 (91.6%) women completed the study. As the pregnancy advanced, there was significant descent of the bladder neck (BN), cervix, and anorectal junction. The hiatal area (HA) was significantly enlarged, with a mean increase of 15.1 ± 24.8% at rest, and 24.7 ± 28.5% at Valsalva, at third trimester when compared with first trimester. Risk factors for stress urinary incontinence (SUI) were: descent of BN at Valsalva (OR 3.2, 95% CI 1.2-8.5), increase in HA at pelvic floor contraction (PFMC; OR 1.3, 95% CI 1.0-1.6), and increase in maternal age (OR 1.1, 95% CI 1.0-1.2), at first trimester; increase in HA at PFMC (OR 1.3, 95% CI 1.1-1.5) at second trimester; and descent of BN at rest (OR 2.3, 95% CI 1.1-4.9) and increase in maternal age (OR 1.1, 95% CI 1.02-1.2) at third trimester. Descent of anorectal junction (OR 1.5, 95% CI 1.1-1.9) and increase in HA at rest (OR 1.2, 95% CI 1.0-1.3) were factors for prolapse symptoms at second and third trimester, respectively., Conclusions: Pelvic floor changes begin during pregnancy. There was significant descent of the BN, cervix, and anorectal junction, and enlargement of the hiatal area, as the pregnancy advanced. SUI was associated with descent of the BN, and prolapse symptoms were associated with an increase in the hiatal area., (© 2013 Royal College of Obstetricians and Gynaecologists.)

Introduction and Hypothesis: This study evaluated factors and their prevalence associated with urinary (UI) and fecal (FI) incontinence during and after a woman's first pregnancy., Methods: Nulliparous Chinese women with no UI or FI before pregnancy were studied with a standardized questionnaire for UI and FI from early pregnancy until 12 months after childbirth. Maternal characteristics and obstetric data were analyzed using descriptive analysis, independent sample t test, chi-square test, and logistic regression., Results: Three hundred and twenty-eight (74.2 %) women completed the study. The prevalence of antenatal UI increased with gestation. Overall, 192 (58.5 %), 60 (18.3 %), and 76 (23.1 %) had normal vaginal delivery, instrumental delivery, and cesarean section, respectively. Twelve months after delivery, prevalence of stress urinary incontinence (SUI) and urge urinary incontinence (UUI) was 25.9 % [95 % confidence interval (CI) 21.5-30.6] and 8.2 % (95 % CI 5.2-11.2), respectively. In those who delivered vaginally, the prevalence was 29.7 % and 9.1 %, respectively. Prevalence of FI was 4.0 % (95 % CI 1.9-6.1). On logistic regression, vaginal delivery [odds ratio (OR) 3.6], antenatal SUI (OR 2.8), and UUI (OR 2.4) were associated with SUI. Antenatal UUI (OR 6.4) and increasing maternal body mass index (BMI) at the first trimester (OR 1.2) were associated with UUI. Antenatal FI was associated with FI (OR 6.1)., Conclusions: The prevalence of SUI, UUI, and FI were 25.9 %, 8.2 %, and 4.0 %, respectively, 12 months after delivery. Vaginal delivery, antenatal SUI, and UUI were associated with SUI; antenatal UUI and increasing maternal BMI at the first trimester were associated with UUI. Antenatal FI was associated with FI. Pregnancy, regardless of route of delivery and obstetric practice, had an effect on UI and FI.

The Health Promotion Board (HPB) has updated the clinical practice guidelines on Treating Tobacco Use and Dependence to provide health professionals in Singapore with evidence-based interventions for smoking cessation. This article reproduces the introduction and executive summary of key guideline recommendations (with recommendations from the guidelines) from the HPB-MOH Clinical Practice Guidelines on Treating Tobacco Use and Dependence, for the information of SMJ readers. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Health Promotion Board website: http://www.hpb.gov.sg/cpg-smoking-cessation. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Background: For ablation of atrioventricular nodal reentrant tachycardia (AVNRT), cryoablation has been shown to be a safe alternative to radiofrequency ablation. However, previous studies have shown a higher recurrence rate with cryoablation compared to radiofrequency ablation., Objective: This study reviewed our experience using cryoablation for typical AVNRT using stringent endpoint criteria for slow pathway ablation, yet preserving the desirable safety profile of cryoablation., Methods: Seventy-five consecutive cases of typical AVNRT underwent cryoablation. Ablation of the AV nodal slow pathway was performed with the goal of eliminating tachycardia, AH jump, and retrograde atrial echo beats. The primary efficacy endpoint was freedom of recurrent supraventricular tachycardia at follow-up. Analysis of AVN characteristics, number of lesions, and complications was performed., Results: Seventy-two (96%) patients met the primary efficacy endpoint over an average follow-up of 34.6 (12.6-68.3) months. In patients who had complete elimination of the slow pathway, there were no recurrences. The presence of an AH jump with a single retrograde echo was highly associated with a recurrence (P = 0.0001). There were no complications, including AV conduction block., Conclusion: The efficacy of cryoablation for management of AVNRT can be comparable to radiofrequency energy if the suggested endpoint of elimination of tachycardia, AH jump with retrograde atrial beats, is met. Prior studies evaluating cryoablation in this setting did not require this endpoint, which could have contributed to the relatively higher rate of late recurrences., (© 2012 Wiley Periodicals, Inc.)

Background: The Inter-facility Transport (IFT) service provided by the Emergency Department (ED) is a vital service in Hong Kong. Patients need to be rapidly transported over distances to access appropriate healthcare facilities., Methods: This study aims 1. to examine the resource utilisation of IFT accompanied by ED staff and 2. to analyse the crude, fixed and variable costs of IFT. A retrospective review was conducted of all IFT from Alice Ho Miu Ling Nethersole Hospital in the New Territories of Hong Kong where ED staff accompanied patients from 1 January 2006 to 31 December 2008. Descriptive analysis was used to evaluate the crude, fixed and variable costs per year for providing an ED-based IFT service., Results: There were 337 transports accompanied by either medical or nursing staff from the ED that accounted for around 2% of all IFT. The most common indication for mobilising the transport team was an unstable clinical condition that required neurosurgical care. The average transport service time was 57.7 min per transport (SD 11.0). Resource utilisation consisted of fixed and variable costs that summed up to a cost of HKD $87,224.3 (USD $11,182.6) per year and the crude cost of providing IFT service by the ED was HKD$852.2 (USD $109.3) per patient., Conclusion: The crude cost of providing IFT service by the ED was reasonable and acceptable.

The aim of this paper is to examine the prescribing patterns and cost of various formulations of metronidazole in a hospital setting over a 3-month period. Oral metronidazole has high bioavailability (98.9%) with peak plasma concentrations averaged at 2.3 h after dosing. Despite the high bioavailability of oral metronidazole, many patients continue to receive metronidazole intravenously when they are suitable for oral preparation. An audit of 120 consecutive patients prescribed metronidazole was conducted at the Liverpool Hospital, NSW, from March to July 2005. There were 65 men and 55 women (age 18-93). Of the 120 patients, 16 were on oral, 1 on rectal and 103 were on intravenous metronidazole. Treatment was initiated based on clinical diagnoses. Potential pathogens were subsequently identified on only 21 occasions. The use of metronidazole as an oral preparation was contraindicated in 27 patients (22.5%) who were nil-by-mouth. Of these, rectally administered metronidazole was contraindicated in only eight patients. The average course of intravenous metronidazole was 8.0 +/- 9.7 days (mean +/- SD). The total number of intravenous metronidazole treatment days was 824. Oral metronidazole would have been possible in 618 out of the 824 days. The estimated cost to administer each dose of oral, suppository and intravenous forms of metronidazole is $A0.11, $A1.34 and $A6.09 respectively. Thus, substantial savings could be achieved if oral metronidazole were to be administered whenever possible. The early use of oral or rectal metronidazole should be encouraged when there are no clinical contraindications.

Objective: To evaluate the risk factors for breast cancer among women in Midwestern and Southeastern Nigeria., Design: A case control study., Setting: University of Benin Teaching hospital, Benin City and University of Port Harcourt Teaching Hospital, Port Harcourt in Nigeria., Subjects: Fifty one women with diagnosis of breast cancer and their age- and sex matched controls were included in the study., Interventions: Data was collected during a 30 minute period after obtaining written informed consent using interviewer-administered questionnaires., Results: Parity > 4 (OR = 0.50, 95% Cl 0.17, 1.46) and duration of breast feeding > 60 months (OR = 0.58, 95% Cl 0.23, 1.48) were associated with reduced risk of breast cancer while birth order > 3 (OR = I.50, 95% Cl 0.25, 8.98), age at first full term pregnancy>20 years (OR = 2.50, 95% Cl 0.78, 7.97) and longer duration of reproductive period (OR = 1.25, 95% Cl 0.34, 4.66) were associated with increased risk of breast cancer., Conclusion: The study has shown that high parity and long duration of breastfeeding are associated with reduced risk while high birth order and late age at first full-term pregnancy are associated with increased risk of breast cancer.

We present a self-consistent integral equation theory for a binary liquid in equilibrium with a disordered medium, based on the formalism of the replica Ornstein-Zernike (ROZ) equations. Specifically, we derive direct formulas for the chemical potentials and the zero-separation theorems (the latter provide a connection between the chemical potentials and the fluid cavity distribution functions). Next we solve a modified-Verlet closure to ROZ equations, which has built-in parameters that can be adjusted to satisfy the zero-separation theorems. The degree of thermodynamic consistency of the theory is also kept under control. We model the binary fluid in random pores as a symmetrical binary mixture of nonadditive hard spheres in a disordered hard-sphere matrix and consider two different values of the nonadditivity parameter and of the quenched matrix packing fraction, at different mixture concentrations. We compare the theoretical structural properties as obtained through the present approach with Percus-Yevick and Martinov-Sarkisov integral equation theories, and assess both structural and thermodynamic properties by performing canonical standard and biased grand canonical Monte Carlo simulations. Our theory appears superior to the other integral equation schemes here examined and provides reliable estimates of the chemical potentials. This feature should be useful in studying the fluid phase behavior of model adsorbates in random pores in general.

A number of epidemiological studies have suggested that cigarette smoking is a risk factor for osteoporosis. Benzo(a)pyrene (BaP) and 7,12-dimethylbenz(a)anthracene (DMBA) are polycyclic aromatic hydrocarbons (PAHs) found in the tar fraction of cigarette smoke, as well as in car exhaust and furnace gases. We hypothesized that BaP and DMBA are responsible, through interaction with the aryl hydrocarbon receptor (AhR), for the bone loss and fragility seen in smoking-related osteoporosis. In this study four groups of 9-month-old Sprague-Dawley rats were examined. An intact group served as controls. A second control was the ovariectomized (ovx) group. The third group (ovx + E(2)) were ovariectomized and also given a continuous basal dose of estrogen by implanted estrogen pellet (0.085 mg of 17beta-estradiol per rat). The fourth group (ovx + E(2) + BaP/DMBA) was ovariectomized with an estradiol pellet, and received subcutaneous injections of 250 microg/kg of BaP/DMBA weekly for 15 weeks. The loss of ovarian function allowed the study of a direct effect of BaP/DMBA on bone while the concomitant estrogen repletion prevented ovx-related bone loss. Dual-energy X-ray absorptiometry (DEXA), histomorphometry, image analysis, and mechanical testing were used to determine the effect of the treatments on bone. The DEXA results showed a significant (p < 0.05) decrease in bone mineral density compared with intact controls with both ovx alone and with ovx + E(2) + BaP/DMBA treatment. The ovx + E(2) rats were similar to the intact controls. The osteoid parameters showed a significant increase (p < 0.05) with BaP/DMBA addition vs. intact controls, mimicking the ovx rats. The ovx + E(2) rats had osteoid parameters comparable to those of intact rats. Bone connectivity was decreased in the ovx and ovx + E(2) + BaP/DMBA animals. Connectivity of the ovx + E(2) rats was comparable to that of intact animals. A decrease in failure force was seen in three-point bending for the ovx + E(2) + BaP/DMBA group and in vertebral compression in both the ovx and ovx + E(2) + BaP/DMBA groups vs. intact controls. The mechanical properties of the ovx + E(2) rats were similar to those of intact rats. These results demonstrate that BaP/DMBA causes a loss of bone mass and bone strength, possibly through an increase in bone turnover. This is the first in vivo study linking environmental toxicants, found in the tar fraction of cigarette smoke and in urban air pollution, to loss of bone mass and strength in estrogen-replete ovx rats.

Purpose: Epidemiological data indicate a sharp increase in urinary calcium stone formation after menopause. We investigated the role of menopausal estrogen replacement therapy on the urinary constituents and characteristics that may influence recurrent calcium oxalate stone disease., Materials and Methods: Urinary constituents in 28 postmenopausal women on estrogen replacement therapy for more than 6 months were compared with those in 41 women who had never been exposed to estrogen after menopause. These 2 groups had a history of recurrent calcium oxalate urolithiasis. A group of age matched, nonstone forming volunteers who were and were not on estrogen served as controls., Results: The 24-hour urine collection revealed significantly higher mean calcium plus or minus standard deviation (188.8 +/- 101.5 versus 129.2 +/- 80.9 mg./24 hours, p <0.01), citrate (576.6 +/- 237.9 versus 306.2 +/- 209.9 mg./24 hours, p <0.001) and agglomeration inhibition (203 +/- 106 versus 159 +/- 81 minutes, p <0.05) in stone forming women who were versus were not on estrogen., Conclusions: Higher urinary citrate and higher agglomeration inhibition in women exposed to estrogen may decrease the risk of subsequent calcium stone formation.

Background: To study the differences in the health status of rural and urban ambulatory elderly in Taipei County., Method: Non-compulsory general health check-up for elderly people over 65 years old in rural and urban areas. The content of the health examination included past medical history, health behavior, physical examination, laboratory examination, electrocardiogram and x-ray. Chi square test, t-test and logistic regression were applied for analysis. Risk factors relating to the cardiovascular system were included in the study. Gender differences affecting the prevalence of diseases and health behavior were also considered in the analysis., Results: Significantly higher proportions of the rural elderly men smoked, drank alcohol, and had hypertension and impaired renal function. On the other hand, higher proportions of rural elderly women were obese and had diabetes, hypertension and renal impairment. The mean plasma glucose level of newly-diagnosed diabetic patients in the rural area was significantly higher than that in the urban area (p < 0.05). Diabetes, obesity, hypercholesterolemia and smoking were significantly associated with hypertension. The odds ratio for hypertension between rural and urban areas was 1.45 (p < 0.0001). The cardiovascular risk-rating score of rural elderly was statistically higher than that of urban elderly (p < 0.001)., Conclusion: There were some minor differences in health status between urban and rural elderly. Health promotion should be varied according to the needs of various communities and various risk groups. Further studies should concentrate on prospective cohort research with well-defined determinants to evaluate whether cost-effective biopsychosocial intervention is necessary.

This study investigated the influence of professional commitment on turnover intentions of nurses. The study also examined the relationships between demographic data, work-related variables and the professional commitment. The self-administered questionnaires were distributed to one fifth of Southern Taiwan's population of nurses (n = 4,000). A total of 2,543 subjects completed the questionnaires with a 63.6% response rate. The nurses exhibited a medium-high degree of overall professional commitment. Age, salary, years in profession and years in organization were correlated significantly with professional commitment by Pearson's correlation. There were significant correlations between professional commitment and marital status, educational level, status of the youngest child, level of position, and family support in Spearman's correlations. Family support, age, level of position and status of hospital were the significant predictors in the final regression analysis model. The discriminant analysis showed that 45.4% of nursing professional commitment was correctly classified in predicting intention to leave the profession and 33.1% in predicting the intention to leave the organization. The study recommended that nursing professional commitment is an important moderator to affect the turnover intention of staff nurses.

Objective: To determine how the magnitude of myopia and its method of correction influence visual field testing., Design: Prospective observational case series, including comparison of spectacles and contact lenses., Participants: One hundred forty-six ophthalmologically normal males 19 to 24 years of age with myopia (spherical equivalent from -0.50 to -14.0 diopters)., Methods: Participants performed automated static threshold perimetry. Refractive errors were corrected using trial lenses and soft contact lenses. Subjects were tested with both methods of correction, the order of which was randomized., Main Outcome Measures: Threshold sensitivity and global indexes., Results: Only one subject (0.7%) had a significant reproducible visual field defect on both methods of correction. Six subjects (4.1%) had a focal visual field defect on one method of correction but not the other. For myopia greater than -4.0 diopters, the mean defect decreased significantly as axial length and degree of myopia increased (P: < 0.01). Similar results were obtained with either method of correction., Conclusions: Threshold sensitivity is reduced in moderate and high myopia, regardless of the method of correction. The surprisingly low prevalence of visual field defects in this myopic population disputes the widely held view that myopia is associated commonly with visual field abnormalities. If field defects are found in myopes on automated perimetry, it is advisable to repeat the test with another method of optical correction to check that such defects are genuine and not related to the method of refractive correction.

The effect of soil moisture on the distribution of Steinernema riobrave in a sand column was determined. Larvae of Pectinophora gossypiella were used to detect S. riobrave infective juveniles (IJ) in each 2.5-cm section of 30-cm-long soil columns. Soil moisture was determined for each section and related to the numbers of nematodes recovered from infected insect baits. Infective juveniles of S. riobrave applied on the sand column surface showed some degree of positive geotaxis. IJ in soil columns with a consistent moisture gradient grouped in the upper 12.7 cm within a water potential range of 40 to 0.0055 MPa (2% to 14% moisture). Nematodes in sand columns that were gradually dehydrating moved down the soil column, aggregating on the 28th day between 15-23 cm in depth. Nematode redistribution over time allowed IJ to remain within a water potential range of 0.1 to 0.012 MPa (5.2% to 9.5% moisture).

Various methods of continuous intracranial pressure (ICP) monitoring during experimental procedures in the rat have been described. However, no systematic comparison of ICP monitoring in the ventricle, brain parenchyma, and cisterna magna has been reported. Since accurate and reliable ICP measurements are important in experimental models of traumatic brain injury, the present study was conducted to compare simultaneous ICP measurements from ventricular, cisterna magna, and intraparenchymal monitors during ICP changes. Subdural hematoma was produced by infusion of 0.3 ml of autologous blood into the subdural space over 6 min. The ventricular and the intraparenchymal fiberoptic catheter produced reliable and comparable pressure recordings, that did not statistically differ (p = 0.4), throughout the one hour monitoring time. In contrast, the cisterna magna catheter was less reliable and produced significantly lower readings throughout the monitoring time (p<0.001). The intraparenchymal device produced greater cortical damage than the ventricular catheter. In conclusion, ventricular ICP monitoring is the preferred method under these circumstances, since it is accurate and induces least brain damage.

Objectives: Analysis of national surveillance data and a seroepidemiologic investigation were conducted to elucidate the causes and epidemiologic characteristics of a measles outbreak in Taoyuan, Taiwan, 1994., Methods: Measles cases were identified through a national surveillance system. Reported cases and their physician or school nurses were interviewed to trace additional suspect cases and were sampled for serologic diagnosis. Measles-specific IgG and IgM were assayed. A confirmed case was defined as being positive for measles IgM test but not having received measles vaccination within the previous 3 months., Results: The outbreak began in Taoyuan City in December 1993 and continued to spread in primary schools and kindergartens, but caused only sporadic cases in neighboring towns. Among 42 confirmed cases, 15 (38%) were primary school children and 16 (38%) were kindergarten children. Among 24 confirmed cases with a vaccination record, 7 had one dose of vaccination, 4 had two doses of vaccination, and 13 (54%) were unvaccinated. The overall measles susceptible proportion at a kindergarten before the outbreak was 8.1% (17/209) and the overall measles cumulative incidence among susceptibles was 0.65 (11/17)., Conclusions: A measles vaccination coverage of 82% with the first dose at 9 months of age and 63% with the second dose (measles, mumps, and rubella) at 15 months was inadequate to block measles virus circulation in Taoyuan City in 1994. The city center, with a growing population, represents a high risk as an epicenter for measles outbreaks. Measles outbreaks may occur in a school population with 92% herd immunity.

A sensitive high-performance liquid chromatographic (HPLC) method was developed and validated to separate and quantitate the levels of L-696,229 (I), a novel human immunodeficiency virus type I non-nucleoside reverse transcriptase inhibitor, and its hydroxy metabolites (II and III) in plasma samples. The procedure involves the addition of a constant known quantity of internal standard to the biological specimen followed by extraction of the compounds of interest into methyl tert.-butyl ether. The organic phase is evaporated to dryness under a gentle stream of nitrogen. The residue is then dissolved in methanol and water and injected onto a reversed-phase HPLC column. A gradient HPLC method is used to elute the compounds which are monitored using UV detection at 319 nm. Absolute calibration factors (from the standard curve) were calculated by analyzing standards, and these factors were used to determine the concentration of drug (I) and its hydroxy metabolites (II and III) in the samples using the internal standard method. The method was linear using a standard concentration range of 50 to 20,000 ng/ml. The limit of quantitation was 50 ng/ml using 200 microliters plasma. The procedure was utilized to monitor plasma levels of I, II and III in acute and chronic toxicity studies in several animal species.

Previous developmental and reproductive toxicity studies in rats with losartan, a potent AT1-selective angiotensin II (AII) receptor antagonist, correlated maternal treatment during gestation day (GD) 15-20 with irreversible renal abnormalities in the F1 generation (Spence et al., '95a,b). Continued treatment through lactation was also associated with increases in pup mortality and decreases in pup body weights that persisted through weaning. The studies presented here were undertaken to quantify fetal and neonatal exposure to losartan when administered to the dam by oral gavage during early gestation, late gestation, and lactation. Following daily oral dosing of 135 mg/kg/day on GD6-15, fetal drug levels were negligible. However, losartan and its active metabolite, EXP3174 (L-158,641) were readily detectable in fetal plasma on GD 20 (estimated AUC values, 50.70 and 167.70 micrograms/hr/ml, respectively) and maternal milk during lactation (1.61 and 1.67 micrograms/ml, respectively). These studies suggest that the relative increased sensitivity of the fetus as compared to the neonate for losartan-induced renal lesions is related to the degree of exposure which is dependent on the time of administration (early gestation vs. late gestation/lactation) and the route of exposure (transplacental or through the milk). Furthermore, the maximum exposure to losartan and EXP3174 correlates with the ontogeny of the renin angiotensin system on approximately GD 17 and the critical period for losartan-induced renal lesions (GD15-20). The data support the hypothesis that the observed adverse fetal and neonatal effects are pharmacologically mediated, presumably through the lack of AT1 receptor stimulation.

Background: Follow-up studies from the mid-1980s showed that 1 to 5 percent of blood donors testing reactive in anti-human immunodeficiency virus type 1 (HIV-1) enzyme immunoassay (EIA) and testing indeterminate in Western blot were infected with HIV-1 and were in the process of seroconverting. The present study was conducted to establish the rate of HIV infection among contemporary anti-HIV-1/HIV type 2 (HIV-2) EIA-reactive, Western blot-indeterminate donors., Study Design and Methods: Donations (n = 607) with indeterminate HIV supplemental test results were identified by screening 3,021,342 donations given from November 1990 through August 1993 at five participating blood centers. Consenting donors were enrolled and samples taken 4 to 8 weeks after donation. Follow-up sera were tested by EIA and Western blot for anti-HIV-1 seroconversion and by type-specific peptide assays for antibodies to HIV-2 and HIV-1 subtype O. Peripheral blood mononuclear cells and/or plasma from the follow-up samples were tested for HIV-1 DNA and/or RNA by polymerase chain reaction. The rate of HIV-1 infection among Western blot-indeterminate donors was also estimated by multiplying the incidence rate of HIV-1 seroconversion in this donor population by the estimated duration of the EIA-reactive and Western blot-indeterminate window during seroconversion (8.5 days)., Results: Supplemental test-indeterminate donors (n = 355) enrolled a median of 38 days after donation; 265 (75%) of these donors were identified as indeterminate after an anti-HIV-1/2 EIA-reactive donation. Enrolled and non-enrolled donors had similar distributions of demographic characteristics and band patterns. Follow-up samples from all 355 donors tested negative for HIV-1 in polymerase chain reaction. Follow-up sera tested Western blot-negative in 54 cases (15%) and Western blot-indeterminate in 299 (84%). Two follow-up sera (0.6%) were interpreted, according to manufacturer's package insert criteria, as Western blot positive with p24 and gp41 bands and/or gp120/160 bands; however, paired testing of index and follow-up sera from these two cases showed identical Western blot and EIA reactivity, and polymerase chain reaction was negative for HIV RNA and DNA, which ruled out HIV infection. The absence of HIV infection in 355 Western blot-indeterminate donors was consistent with our incidence-based model analysis, which yielded an estimate of one HIV-1 infection for every 215 Western blot-indeterminate donations (95% CI, 1/39-1/8333)., Conclusion: Contemporary blood donors classified as indeterminate in supplemental HIV testing are infrequently infected with HIV. Donors whose follow-up samples test negative in anti-HIV-1/2 EIAs and negative or persistently indeterminate in Western blots should be considered eligible for reinstatement.

Background: Almost all human immunodeficiency virus (HIV) transmission via blood or tissues that has occurred since anti-HIV screening was implemented in 1985 is traceable to blood given after infection but before antibody seroconversion, a time that is referred to as the window period. In this study, the performance of newer assays designed to detect viral and serologic markers soon after infection is assessed, and the reduction in the window period achieved by these assays is estimated., Study Design and Methods: Three cohort studies of persons at high risk for acquiring HIV infection were identified. These studies included well-controlled HIV type 1 (HIV-1) polymerase chain reaction (PCR) analyses of serial preseroconversion specimens from HIV-1-seroconverting homosexual men or intravenous drug users. Of 81 enrollees with anti-HIV-1 seroconversion documented by a viral lysate anti-HIV-1 enzyme immunosorbent assay (EIA) available in 1989, 13 (16%) had PCR-positive preseroconversion specimens. In the present study, sera from these 13 PCR-positive samples were further tested for anti-HIV by 10 contemporary EIAs and 6 supplemental assays, as well as being tested for plasma p24 antigen and HIV-1 RNA. Preseroconversion sera from 38 HIV-1 DNA PCR-negative cohort participants were also tested by selected anti-HIV EIAs and tested for p24 antigen and HIV-1 RNA. On the basis of these laboratory data and the intervals between blood drawing in all 81 men, the reduction in the preseroconversion window period achieved by these new assays was estimated with a mathematical model developed to analyze seroconversion data., Results: Nine (69%) of the 13 preseroconversion PCR-positive samples had anti-HIV that was detectable by one or more contemporary anti-HIV-1 or anti-HIV type 2 EIA. Supplemental antibody assays were negative on all four EIA-nonreactive preseroconversion samples and negative or indeterminate on a high proportion of the nine EIA-reactive PCR-positive samples. Eight (61%) of the 13 samples were p24 antigen-positive, and 11 (85%) were HIV-1 RNA-positive. The estimated reductions in the window period (relative to the index viral lysate-based anti-HIV EIA) were as follows: contemporary anti-HIV-1/2 EIAs, 20.3 days (95% Cl, 8.0-32.5); p24 antigen and DNA PCR, 26.4 days (95% Cl, 12.6-38.7); and RNA PCR, 31.0 days (95% Cl, 16.7-45.3)., Conclusion: Recent improvement in the sensitivity of anti-HIV assays has resulted in significant shortening of the preseroconversion window period. Consequently, the incremental reduction in the window period that could be achieved by implementing direct virus-detection assays has diminished significantly.

Previously we demonstrated that the contraction of collagen fibrillar matrices (CFM) by fibroblasts was significantly reduced when high concentrations (> 1 mg/ml) of hyaluronan were present in the media. This highlights the prominent role of hyaluronan in preventing scar formation during fetal wound healing. In the present study, we covalently crosslinked different concentrations of CNBr-activated hyaluronan to CFM and investigated the ability of fibroblasts to contract these matrices. Matrices are not contracted when optimal concentrations of CNBr-activated hyaluronan are crosslinked to collagen. Biochemical and cytological analysis of these matrices suggests that hyaluronan strengthens the collagen fibrils and blocks direct communication between fibroblasts and the collagen fibrils. Based on current evidence we are able to propose two molecular crosslinking models, multiple point attachment and simple point attachment between CNBr-activated hyaluronan and collagen molecules, hypotheses supported by the susceptibility of these matrices to digestion by collagenase.

Hyaluronan, found in high concentrations in fetal tissues, appears to have a major role in preventing scar formation in fetal wounds. Nevertheless, its role in inhibiting wound contractures associated with scar formation has not been clearly demonstrated. Our current study evaluated the effects of hyaluronan using an in vitro floating collagen fibrillar matrix (CFM) contraction model. The results demonstrated that the contraction of CFM by fibroblasts was significantly reduced when high concentrations (> 1 mg/mL) of hyaluronan were present in the media. This phenomenon is unique to hyaluronan, because chondroitin sulfate was ineffective in this connection. Fibroblast migration and proliferation studies indicated that high concentrations of hyaluronan stimulated cell migration and had no cytotoxic effects. Some possible mechanisms by which high concentrations of hyaluronan reduced CFM contraction by fibroblasts were proposed. Because the viscosity of a hyaluronan solution is much greater than that of chondroitin sulfate, and this increases with concentration, we investigated whether this property in itself was an important factor in inhibiting CFM contraction. No direct correlation was found between the viscosity of glycosaminoglycans and their ability to reduce CFM contraction.

We examined changes in the patterns of the rates of smoking initiation in the United States by gender for 1950, 1965, and 1980. Data from National Health Interview Surveys on the ages people started smoking (survey years 1970, 1978, 1979, 1980, 1987, and 1988) were used to construct age-specific rates of smoking initiation for males and females 10 to 24 years of age for 1950, 1965, and 1980. We used information from 87,483 white respondents who were between 20 and 50 years of age when surveyed. In 1950, initiation was higher for males of all ages than for females, and smoking initiation rates were higher among those age 18 years and older compared to those younger. Although still somewhat higher, the rates for males in 1965 had declined much more than those for females, and the tendency for higher rates in older youth was still evident. In 1980, no gender difference was seen and most initiation clearly took place in those younger than 18 years of age. We concluded that the public health campaign has been successful in convincing older youth not to smoke. However, smoking initiation rates in younger adolescents have changed little, indicating that new approaches to tobacco control are necessary if smoking prevalence in the United States is to be further reduced.

Hyaluronan, which is found in high concentrations in fetal tissues, has been suggested to play a major role in preventing scar formation in fetal wounds. We have developed a floating collagen fibrillar matrix (CFM) made out of reconstituted type I collagen for the purpose of evaluating the ability of hyaluronan to inhibit the fibroblast induced contraction of the matrix. When hyaluronan is covalently bound to collagen it appears to better support fibroblast proliferation and matrices are less contractible by these cells than when hyaluronan interacts only ionically. When hyaluronan is bridged between collagen fibrils by a network of extensive covalent crosslinks, contractibility by fibroblasts is abolished. These modified collagen matrices may prove to be very useful in the development of bioprostheses and implants.

Arterial post-stenotic dilatation (PSD) is a fusiform swelling immediately down-stream to a stenosis. It is characterized by the presence of turbulent blood flow and wall vibration which has been claimed by others to be causal by producing structural weakening. We tested the hypothesis that vibration causes PSD in vivo by attaching electromagnetic and pneumatic vibrators to the aortic wall in chronic rabbits. We also observed whether mechanical vibration of the aorta in vivo influenced the distribution of oil-red-O lesions during one percent dietary cholesterol feeding. Low mass vibration gauges were developed to measure the vibration. Electromechanical vibrators having a ceramic magnet slug within a coil supplied with 50 Hz were glued to the aorta of chronic rabbits and the vibration maintained for an average of 8 weeks. Despite greater amounts of energy imparted to the wall there was no dilatation or difference in oil-red-O staining from the controls. Five weeks vibration at 100 Hz and an amplitude equal to the normal diameter pulse also produced no dilatation. We conclude that vibration does not cause PSD in vivo and suggest that its cause is likely to involve the vascular muscle stimulated by the effect of turbulent flow on the endothelium.

A stereospecific HPLC bioanalytical method was developed for quantitation of the enantiomers of MK-0571, a leukotriene D4 receptor antagonist. The procedure involves the addition of an internal standard analog to the biological matrix followed by extraction of the free acids into ethyl acetate. The acids are subsequently reacted with the homochiral reagent, (+)-(R)-alpha-(1-naphthyl)ethylamine (NEA) to form diastereomers. Following removal of excess reagent and side products by a dilute acid wash, the NEA-MK-0571 diastereomers are separated on a phenyl urea chiral column using a mobile phase containing hexane, isopropanol, and acetonitrile and are detected with a fluorescence detector. The sensitivity of the method is such that 50 ng of each enantiomer can be quantitated. In the 0.05 to 10 micrograms range the recoveries of the enantiomers of MK-0571 from plasma were 100.4 +/- 7.9% and 100.0 +/- 7.2%. NMR and mass spectral data confirmed the structure of the derivative. The method has been utilized in drug safety evaluation studies to demonstrate enantioselectivity in disposition of the enantiomers of MK-0571 in rats and monkeys but not in mice.

The reversibility of glutaraldehyde crosslinks has been suggested as a reason for failure of long-term bioprosthetic implants. The stability of such crosslinks was investigated in tendons and model compounds. Small but cytotoxic levels of glutaraldehyde were still released from crosslinked tendons even after these tendons were extensively rinsed for up to 6 months. The toxic effect was evidenced by the death of fibroblasts surrounding a midsection piece of rinsed crosslinked tendon, while the end section pieces did not show toxic effects. The formation and stability of glutaraldehyde modified [14C]-L-lysine derivatives were investigated. The polymerization of glutaraldehyde with amino compounds was initially fast but continued to proceed slowly for months. Degradation of high-molecular-weight soluble polymers was detected by gel filtration chromatography. Low-molecular-weight soluble materials were also released from insoluble products which were formed when high concentrations of glutaraldehyde and radioactive lysine were reacted. These chemical and biological studies suggest that local cytotoxicity of glutaraldehyde crosslinked bioprostheses may be due to unstable glutaraldehyde polymers that persist in the interstices of crosslinked tissues.