50 results on '"Slavik, T"'
Search Results
2. Pharmaceutical management of bone catabolism: the bisphosphonates
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Raubenheimer, EJ, Noffke, CEE, Lemmer, LB, Slavik, T, van Heerden, WFP, and Miniggio, HD
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bone metastases ,glucocorticoid bone disease ,jaw bone necrosis ,osteogenesis imperfecta ,Paget's disease of bone ,bisphosphonates ,osteoporosis - Abstract
BACKGROUND: Conditions associated with catabolism of bone are common and progress sub-clinically with devastating skeletal consequences. Over the past two decades, bisphosphonates have become increasingly popular for the preventative management of the skeleton in these conditions METHODS: Recent literature pertaining to the mechanisms of action, clinical indications and complications of bisphosphonate therapy was retrieved using Google Scholar and Pubmed. AIMS OF STUDY: To provide an overview of the mechanisms of action, indications, contraindications and complications of the bisphosphonates available for clinical use in South Africa. RESULTS: Despite the availability of alternative management regimens, bisphosphonates remain the pharmaceuticals of choice for the management of hypercalcaemia and generalised catabolic skeletal disorders such as osteoporosis, skeletal metastatic disease, Paget's disease of bone, glucocorticoid bone disease and osteogenesis imperfecta. Although adverse complications such as tachycardia, bowel and oesophageal irritation, pain, jawbone necrosis and atypical femur fractures are well documented, information remains limited on the long-term effects of bisphosphonate therapy on skeletal health. This manuscript provides an update on the mechanisms of action, principles applied to the selection of the most appropriate management regimen, monitoring of the response and complications of the bisphosphonates marketed in South Africa Level of evidence: Level 5
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- 2019
3. Superficial spreading cervical squamous cell carcinoma in situ with extensive endomyometrial infiltration masquerading as a primary endometrial cancer.
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Olivier, H. J., Snyman, L. C., Oliva, E., and Slavik, T.
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PAPILLOMAVIRUSES ,MYOMETRIUM ,VAGINAL discharge ,HYSTERECTOMY ,BIOPSY ,IMMUNOHISTOCHEMISTRY ,CERVICAL cancer ,DIFFERENTIAL diagnosis ,DISEASES ,CERVICAL intraepithelial neoplasia ,CERVIX uteri ,ADJUVANT treatment of cancer ,CHEMORADIOTHERAPY ,ENDOMETRIAL tumors ,POSTMENOPAUSE ,CYTOLOGY ,POLYMERASE chain reaction ,SQUAMOUS cell carcinoma ,CARCINOMA in situ ,HEMORRHAGE ,ENDOMETRIUM - Abstract
The presence of squamous cell carcinoma (SCC) on endometrial histology raises the possibility of a primary endometrial carcinoma, as well as secondary endometrial involvement by SCC from another site, especially the cervix. This distinction relies on numerous cardinal clinical and pathologic findings and may occasionally be problematic. We document an unusual tumour in a postmenopausal woman who presented with clinical and radiologic features of a primary endometrial cancer, confirmed on endometrial histology as a keratinising SCC. Subsequent pathologic evaluation of the hysterectomy specimen, however, demonstrated an exclusively in situ cervical SCC, with extensive endometrial intramucosal spread and widespread infiltration of the myometrium, macroscopically mimicking a primary endometrial neoplasm. We review the pathologic distinction between primary endometrial SCC and secondary corpus involvement of cervical SCC, as well as the broader differential diagnosis when SCC is identified on endometrial histology. [ABSTRACT FROM AUTHOR]
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- 2022
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4. EXPRESSION OF THE INTERMEDIATE FILAMENT PERIPHERIN IN FETAL MELANOCYTES
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Prieto, V G, Slavik, T, Reed, J A, Burchette, J L, and Shea, C R
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- 1998
5. An unusual case of abdominal mycobacterial infection: Case report and literature review.
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Ekermans, P., Gama, R. de, Kock, C., Hoosien, E., Slavik, T., Marshall, T., Corcoran, C., Ingen, J. van, Ekermans, P., Gama, R. de, Kock, C., Hoosien, E., Slavik, T., Marshall, T., Corcoran, C., and Ingen, J. van
- Abstract
Contains fulltext : 208844.pdf (publisher's version ) (Open Access), This article presents a case of an HIV-infected paediatric patient with an unusual Mycobacterium genavense infection with predominantly abdominal organ involvement.
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- 2019
6. Retrospective determination of HIV-1 status by a PCR method on paraffin wax embedded sections
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Slavik, T., Wolfaardt, M., van Zyl, H., and Simson, I. W.
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- 1995
7. Pharmaceutical management of bone catabolism: the bisphosphonates
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Raubenheimer, EJ, primary, Noffke, CEE, additional, Lemmer, LB, additional, Slavik, T, additional, van Heerden, WFP, additional, and Miniggio, HD, additional
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- 2019
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8. Recent advances in the pharmaceutical manipulation of bone remodelling: the quest for a healthy skeleton
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Raubenheimer, EJ, primary, Miniggio, HD, additional, Lemmer, LB, additional, Slavik, T, additional, and van Heerden, WFP, additional
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- 2018
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9. Quantitative PCR and IHC staining for HER-2/neu. Retrospective comparative case study of breast cancer specimens selected for chromosome 17 aneusomy by FISH
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Simonic, I., Manasse, B., Smocilac, S., Stipinovich, G., Lombard, P., and Slavik, T.
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Human genetics -- Research ,Breast cancer -- Genetic aspects ,Aneurysms -- Genetic aspects ,Biological sciences - Published
- 2001
10. 3 ACTIVATED INTESTINAL MACROPHAGES IN LIVER CIRRHOSIS PRODUCE NITRIC OXIDE AND DISRUPT INTESTINAL BARRIER FUNCTION
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du Plessis, J., primary, Roos, L., additional, Slavik, T., additional, Stivaktas, P.I., additional, Nieuwoudt, M., additional, van Wyk, S.G., additional, Vieira, W.A., additional, Pretorius, E., additional, Beukes, M., additional, and van der Merwe, S.W., additional
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- 2012
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11. Prophylactic human papillomavirus vaccination against cervical cancer: a summarised resource for clinicians
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Lindeque, B G, primary, Dreyer, G, additional, Botha, H, additional, Moodley, T, additional, Mouton, A, additional, Moodley, M, additional, Soeters, R., additional, Smith, T, additional, Cooreman, N, additional, Guidozzi, F, additional, Hoosen, A, additional, Koller, B, additional, Turner, C, additional, Moodley, J, additional, Godi, N P, additional, Voyi, K, additional, Slavik, T, additional, Whittaker, J, additional, Williamsen, A, additional, and Rogers, L, additional
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- 2011
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12. Pathology of gestational trophoblastic neoplasia: a review with recent insights
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Slavik, T, primary
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- 2010
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13. Triple negative, basal-like and BRCA1-associated breast cancers – what’s the difference and should anyone care?
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Slavik, T, primary
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- 2009
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14. Thermoanalytical studies of organic compounds
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Domagalina, E. and Slavik, T.
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- 1979
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15. Pregnancy rate after the transfer of sheep embryos originated from randomly chosen oocytes matured and fertilized in vitro
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Slavik, T., primary, Fulka, J., additional, and Goll, I., additional
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- 1992
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16. Effect of recombinant bovine somatotropin on follicular growth and quality of oocytes in cattle
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Pavlok, A., Koutecka, L., Krejor, P., Slavik, T., Cerman, J., Slaba, J., and Dorn, D.
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- 1996
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17. Effect of glycerol on the penetrating ability of fresh ram spermatozoa with zona-free hamster eggs
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Slavik, T., primary
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- 1987
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18. In vitro fertilization of intact sheep and cattle oocytes with goat spermatozoa
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Slavík, T. and Fulka, J.
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- 1992
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19. Impaired CD4+ T-cell restoration in the small versus large intestine of HIV-1-positive South Africans receiving combination antiretroviral therapy
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Robert P. Bond, Schalk Van der Merwe, Christopher J. Seebregts, Sharon Cassol, Susan Malfeld, Tomas Slavik, Theresa M. Rossouw, Edana Cassol, Phetole Walter Mahasha, Guido Poli, Cassol, E, Malfeld, S, Mahasha, P, Bond, R, Slavik, T, Seebregts, C, Poli, Guido, Cassol, S, van der Merwe, Sw, and Rossouw, T.
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Adult ,CD4-Positive T-Lymphocytes ,Male ,medicine.medical_specialty ,T cell ,Biopsy ,Ileum ,HIV Infections ,Biology ,CD38 ,CD8-Positive T-Lymphocytes ,Gastroenterology ,Jejunum ,South Africa ,Young Adult ,Internal medicine ,Antiretroviral Therapy, Highly Active ,Intestine, Small ,medicine ,Immunology and Allergy ,Humans ,Large intestine ,Intestine, Large ,Intestinal Mucosa ,Middle Aged ,Flow Cytometry ,Small intestine ,Infectious Diseases ,medicine.anatomical_structure ,Treatment Outcome ,Anti-Retroviral Agents ,Duodenum ,Female ,CD8 - Abstract
BACKGROUND Human immunodeficiency virus type 1 (HIV-1) infection is associated with a massive depletion of intestinal CD4(+) T cells that is only partially reversed by combination antiretroviral therapy (cART). Here, we assessed the ability of nucleoside reverse-transcriptase inhibitor/nonnucleoside reverse-transcriptase inhibitor treatment to restore the CD4(+) T-cell populations in the intestine of South African patients with AIDS. METHODS Thirty-eight patients with advanced HIV-1 infection who had chronic diarrhea (duration, >4 weeks) and/or unintentional weight loss (>10% decrease from baseline) of uncertain etiology were enrolled. Blood specimens were collected monthly, and gastrointestinal tract biopsy specimens were collected before cART initiation (from the duodenum, jejunum, ileum, and colon), 3 months after cART initiation (from the duodenum), and 6 months after cART initiation (from the duodenum and colon). CD4(+), CD8(+), and CD38(+)CD8(+) T cells were quantified by flow cytometry and immunohistochemistry analyses, and the HIV-1 RNA load was determined by the Nuclisens assay. RESULTS CD4(+) T-cell and HIV-1 RNA levels were significantly lower, whereas CD8(+) T-cell levels, including activated CD38(+)CD8(+) T cell levels, were higher in the duodenum and jejunum, compared with the colon. After 6 months of cART, a significant but incomplete recovery of CD4(+) T cells was detected in the colon and peripheral blood but not in the duodenum. Failed restoration of the CD4(+) T-cell count in the duodenum was associated with nonspecific enteritis and CD8(+) T-cell activation. CONCLUSIONS Strategies that target inflammation and immune activation in the small intestine may be required to expedite CD4(+) T-cell recovery and improve therapeutic outcomes.
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- 2013
20. Esophageal lymphocytosis: exploring the knowns and unknowns of this pattern of esophageal injury.
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Coady LC, Sheahan K, Brown IS, Carneiro F, Gill AJ, Kumarasinghe P, Kushima R, Lauwers GY, Pai RK, Shepherd NA, Slavik T, Srivastava A, and Langner C
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- Humans, Diagnosis, Differential, Esophageal Mucosa pathology, Esophagus pathology, Esophagoscopy, Lymphocytes immunology, Deglutition Disorders etiology, Deglutition Disorders diagnosis, Lymphocytosis pathology, Lymphocytosis diagnosis, Lymphocytosis etiology, Esophagitis diagnosis, Esophagitis pathology, Esophagitis immunology
- Abstract
Introduction: Lymphocyte-rich inflammation of the esophageal mucosa has gained increased awareness among pathologists and clinicians recently. Patients usually present with symptoms of esophageal dysfunction, including dysphagia and food bolus impaction. Endoscopy may show changes similar to eosinophilic esophagitis but may also be entirely normal ('microscopic esophagitis'). Three morphological subtypes or variant forms have been described which include lymphocytic, lichenoid and lymphocyte-predominant esophagitis. These need to be discriminated against other distinct causes of esophageal lymphocytosis, such as gastro-esophageal reflux disease and Candida infection., Areas Covered: This review provides an overview of diagnostic criteria and clinical associations of the disorder and presents an algorithmic approach to diagnosis. A comprehensive literature review was conducted using PubMed, Medline and Google Scholar databases to identify articles related to lymphocyte-rich esophageal inflammation, published up to March 2024., Expert Opinion: Lymphocyte-rich inflammation needs to be included in the differential diagnosis and clinical work-up of patients with esophageal dysfunction. There is currently considerable morphological overlap among published subtypes or variant forms. Follow-up studies of affected individuals are needed to formalize diagnostic parameters and identify the clinical course of disease in order to optimize treatment modalities.
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- 2024
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21. Interobserver agreement of estimating the extent of intestinal metaplasia in patients with chronic atrophic gastritis.
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Lerch JM, Pai RK, Brown I, Gill AJ, Jain D, Kővári B, Kushima R, Sheahan K, Slavik T, Srivastava A, Lauwers GY, and Langner C
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- Humans, Metaplasia, Observer Variation, Gastritis, Atrophic diagnosis, Gastritis, Atrophic pathology, Helicobacter Infections pathology, Helicobacter pylori, Precancerous Conditions pathology, Stomach Neoplasms pathology
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The extent of gastric intestinal metaplasia (GIM) can be used to determine the risk of gastric cancer. Eleven international gastrointestinal expert pathologists estimated the extent of GIM on haematoxylin and eosin (H&E)- and Alcian blue-Periodic acid Schiff (AB-PAS)-stained slides of 46 antrum biopsies in 5% increments. Interobserver agreement was tested with the intraclass correlation coefficient (ICC). Correlation between standard deviation and extent of GIM was evaluated with the Spearman correlation. The interobserver agreement was very good (ICC = 0.983, 95% confidence interval (CI) 0.975-0.990). The use of AB-PAS did not increase the agreement (ICC = 0.975, 95% CI 0.961-0.985). Cases with a higher amount of metaplastic epithelium demonstrated a higher standard deviation (rs = 0.644; p < 0.01), suggesting lower diagnostic accuracy in cases with extensive GIM. In conclusion, estimating the extent of GIM on H&E-stained slides in patients with chronic atrophic gastritis can be achieved satisfactorily with high interobserver agreement, at least among international expert gastrointestinal pathologists., (© 2021. The Author(s).)
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- 2022
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22. Subtyping intestinal metaplasia in patients with chronic atrophic gastritis: an interobserver variability study.
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Lerch JM, Pai RK, Brown I, Gill AJ, Jain D, Kővári B, Kushima R, Sheahan K, Slavik T, Srivastava A, Lauwers GY, and Langner C
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- Biopsy, Humans, Metaplasia, Observer Variation, Gastritis, Atrophic diagnosis, Gastritis, Atrophic pathology, Precancerous Conditions pathology, Stomach Neoplasms pathology
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Incomplete gastric intestinal metaplasia (GIM) is associated with an increased risk of gastric cancer. We aimed to examine the interobserver variability of GIM subtyping (incomplete vs complete) in histological diagnosis of patients with chronic atrophic gastritis and to identify factors with potential impact on agreement. Nine international gastrointestinal expert pathologists assessed 46 cases with complete, incomplete or mixed-type GIM on scanned haematoxylin and eosin (H&E)-stained slides. Results were compared with the consensus diagnosis driven by two experts. Interobserver variability was evaluated by kappa statistics. Focusing on the predominant pattern, the agreement between each observer and the consensus diagnosis ranged from 78% to 98%. The level of agreement was moderate to almost perfect (weighted kappa=0.464-0.984). The participating pathologists reached substantial overall agreement (Fleiss' kappa=0.716, 95% confidence interval 0.677-0.755). Misclassification with potential impact on clinical decision making occurred in 5.7% of case ratings. The pattern of GIM (pure GIM versus mixed-type GIM) differed significantly between cases with high and low agreement (p=0.010), while the number of biopsy pieces per sample and the portion of mucosal surface involved by GIM did not. Pathologists who apply subtyping in daily routine performed better than those who do not (p=0.040). In conclusion, subtyping GIM on H&E-stained slides can be achieved satisfactorily with high interobserver agreement. The implementation of GIM subtyping as a risk stratifying tool in current practice guidelines by the European Society of Gastrointestinal Endoscopy (ESGE) and the American Gastroenterological Association (AGA) carries a low rate of misclassification, at least among gastrointestinal expert pathologists., (Copyright © 2022 Royal College of Pathologists of Australasia. Published by Elsevier B.V. All rights reserved.)
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- 2022
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23. The diagnosis of clinically significant oesophageal Candida infections: a reappraisal of clinicopathological findings.
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Hissong E, Schechter S, Mowers J, Yantiss RK, Slavik T, Cheng J, and Lamps LW
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- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Esophagus microbiology, Female, Humans, Infant, Male, Middle Aged, Retrospective Studies, Young Adult, Candidiasis diagnosis, Esophagitis diagnosis, Esophagitis microbiology
- Abstract
Aims: Distinguishing true oesophageal Candida infections from oral contaminants is a common diagnostic issue. Historically, histological features believed to indicate true infection included epithelial invasion by pseudohyphae and intraepithelial neutrophils. Whether or not these features correlate with endoscopic lesions, symptoms and response to therapy has never been tested in a large cohort. The aim of this study was to determine whether specific histological features correlate with clinical and endoscopic findings when Candida is found in oesophageal biopsies., Methods and Results: We reviewed 271 biopsies in which Candida was detected. Cases were evaluated for the presence of desquamated epithelial cells, location/type of fungal forms, neutrophils, and ulceration. Medical records were reviewed for clinical history, endoscopic lesions, and response to antifungal therapy. Statistical analysis was used to determine whether any histological features significantly correlated with clinical variables. There were 120 males and 151 females with a mean age of 42 years. Fifty-nine per cent had symptoms referable to the oesophagus, particularly dysphagia (36%). Most (73%) patients had abnormal endoscopic findings, with plaques, ulcers, or macroscopic evidence of oesophagitis. Seventy-one per cent of patients with documented antifungal therapy showed symptomatic improvement. Overall, there was no statistically significant correlation between any histological feature and presenting symptoms, endoscopic findings, or response to therapy. Importantly, the lack of pseudohyphae, demonstrable invasion of intact epithelium or neutrophilic infiltrates did not exclude clinically significant infection., Conclusions: We conclude that detection of Candida in oesophageal biopsies is always potentially clinically significant. Treatment decisions should be made on the basis of an integration of clinical, endoscopic and histological findings., (© 2020 John Wiley & Sons Ltd.)
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- 2020
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24. A de novo 2.2 Mb recurrent 17q23.1q23.2 deletion unmasks novel putative regulatory non-coding SNVs associated with lethal lung hypoplasia and pulmonary hypertension: a case report.
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Karolak JA, Gambin T, Honey EM, Slavik T, Popek E, and Stankiewicz P
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- Fatal Outcome, Female, Humans, Hypertension, Pulmonary pathology, Infant, Newborn, Lung pathology, Chromosome Deletion, Chromosomes, Human, Pair 17 genetics, Hypertension, Pulmonary genetics, Polymorphism, Single Nucleotide, Exome Sequencing
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Background: Application of whole genome sequencing (WGS) enables identification of non-coding variants that play a phenotype-modifying role and are undetectable by exome sequencing. Recently, non-coding regulatory single nucleotide variants (SNVs) have been reported in patients with lethal lung developmental disorders (LLDDs) or congenital scoliosis with recurrent copy-number variant (CNV) deletions at 17q23.1q23.2 or 16p11.2, respectively., Case Presentation: Here, we report a deceased newborn with pulmonary hypertension and pulmonary interstitial emphysema with features suggestive of pulmonary hypoplasia, resulting in respiratory failure and neonatal death soon after birth. Using the array comparative genomic hybridization and WGS, two heterozygous recurrent CNV deletions: ~ 2.2 Mb on 17q23.1q23.2, involving TBX4, and ~ 600 kb on 16p11.2, involving TBX6, that both arose de novo on maternal chromosomes were identified. In the predicted lung-specific enhancer upstream to TBX4, we have detected seven novel putative regulatory non-coding SNVs that were absent in 13 control individuals with the overlapping deletions but without any structural lung anomalies., Conclusions: Our findings further support a recently reported model of complex compound inheritance of LLDD in which both non-coding and coding heterozygous TBX4 variants contribute to the lung phenotype. In addition, this is the first report of a patient with combined de novo heterozygous recurrent 17q23.1q23.2 and 16p11.2 CNV deletions.
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- 2020
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25. An unusual case of abdominal mycobacterial infection: Case report and literature review.
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Ekermans P, de Gama R, Kock C, Hoosien E, Slavik T, Marshall T, Corcoran C, and van Ingen J
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This article presents a case of an HIV-infected paediatric patient with an unusual Mycobacterium genavense infection with predominantly abdominal organ involvement., Competing Interests: The authors have no conflict of interests.
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- 2019
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26. Uterine PEComas: A Morphologic, Immunohistochemical, and Molecular Analysis of 32 Tumors.
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Bennett JA, Braga AC, Pinto A, Van de Vijver K, Cornejo K, Pesci A, Zhang L, Morales-Oyarvide V, Kiyokawa T, Zannoni GF, Carlson J, Slavik T, Tornos C, Antonescu CR, and Oliva E
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- Adult, Aged, Basic Helix-Loop-Helix Leucine Zipper Transcription Factors genetics, DNA-Binding Proteins genetics, Female, Gene Fusion, Genetic Predisposition to Disease, Humans, Middle Aged, Mitosis, Phenotype, Predictive Value of Tests, Reproducibility of Results, Tumor Burden, Biomarkers, Tumor analysis, Biomarkers, Tumor genetics, Epithelioid Cells chemistry, Epithelioid Cells pathology, Immunohistochemistry, In Situ Hybridization, Fluorescence, Perivascular Epithelioid Cell Neoplasms chemistry, Perivascular Epithelioid Cell Neoplasms genetics, Perivascular Epithelioid Cell Neoplasms pathology, Perivascular Epithelioid Cell Neoplasms surgery, Uterine Neoplasms chemistry, Uterine Neoplasms genetics, Uterine Neoplasms pathology, Uterine Neoplasms surgery
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Uterine perivascular epithelioid cell tumors (PEComas) are rare neoplasms that may show overlapping morphology and immunohistochemistry with uterine smooth muscle tumors. In this study, we evaluated the morphologic, immunohistochemical, and molecular features of 32 PEComas, including 11 with aggressive behavior. Two distinct morphologies were observed: classic (n=30) and those with a lymphangioleiomyomatosis appearance (n=2). In the former, patients ranged from 32 to 77 (mean: 51) years and 13% had tuberous sclerosis. Tumors ranged from 0.2 to 17 (mean: 5.5) cm with 77% arising in the corpus. Epithelioid cells were present in 100% and a spindled component was seen in 37%. Nuclear atypia was low (53%), intermediate (17%), or high (30%). Mitoses ranged from 0 to 36 (mean: 6) and 0 to 133 (mean: 19) per 10 and 50 high-power fields, with atypical mitoses present in 30%. Thin and delicate vessels were noted in 100%, clear/eosinophilic and granular cytoplasm in 93%, stromal hyalinization in 73%, necrosis in 30%, and lymphovascular invasion in 10%. All tumors were positive for HMB-45, cathepsin K, and at least one muscle marker, with most expressing melan-A (77%) and/or MiTF (79%). A PSF-TFE3 fusion was identified in one while another showed a RAD51B-OPHN1 fusion. Follow-up ranged from 2 to 175 (mean: 41) months, with 63% of patients alive and well, 20% dead of disease, 13% alive with disease, and 3% dead from other causes. In the latter group (n=2), patients were 39 and 49 years old, one had tuberous sclerosis, while the other had pulmonary lymphangioleiomyomatosis. Both tumors expressed HMB-45, cathepsin K, and muscle markers, but lacked TFE3 and RAD51B rearrangements. The 2 patients are currently alive and well. Application of gynecologic-specific criteria (≥4 features required for malignancy: size ≥5 cm, high-grade atypia, mitoses >1/50 high-power fields, necrosis, and lymphovascular invasion) for predicting outcome misclassified 36% (4/11) of aggressive tumors; thus, a modified algorithm with a threshold of 3 of these features is recommended to classify a PEComa as malignant.
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- 2018
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27. Thymoma-associated multiorgan autoimmunity with exclusive gastrointestinal tract involvement: case report and review of the literature.
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Slavik T, Potgieter FM, and Brittain D
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- Aged, Humans, Male, Skin pathology, Thymus Neoplasms diagnosis, Autoimmune Diseases immunology, Autoimmunity, Gastrointestinal Tract pathology, Thymoma pathology, Thymus Neoplasms pathology
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Thymoma-associated multiorgan autoimmunity (TAMA) is a recently delineated and rare paraneoplastic syndrome reported in patients with thymoma. The disorder is characterized by graft-versus-host disease-like pathology affecting the skin, gastrointestinal tract (GIT), and liver, and is usually associated with a poor outcome. We document a case of TAMA with exclusive GIT involvement which included the stomach, small and large bowel, presenting in a 66-year-old male patient 5 years after complete resection of a type B2 thymoma. A brief review is provided of this scarce syndrome, the GIT pathology described in the 21 TAMA cases reported to date, and the unique characteristics of patients with exclusive GIT involvement by this acquired autoimmune disorder.
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- 2018
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28. Navigating the jungles of tropical infectious gastrointestinal pathology: a pattern-based approach to the endoscopic biopsy.
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Slavik T and Lauwers GY
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- Biopsy, Communicable Diseases parasitology, Communicable Diseases pathology, Cytodiagnosis methods, Endoscopy, Digestive System, Gastrointestinal Diseases pathology, Humans, Communicable Diseases diagnosis, Gastrointestinal Diseases diagnosis, Gastrointestinal Diseases parasitology, Tropical Medicine methods
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International travels and global human migration have had the unforeseen consequence of increasing the exposure of histopathologists in developed countries to the pathology of tropical infectious disease. The gastrointestinal tract (GIT) is often the primary site of infection due to the faecal-oral route of transmission and the high risk of exposure to contaminated water, food or soil when travelling to these regions. Whilst current microbiologic techniques are far more sensitive than histology in detecting infectious pathogens, the histopathologist nonetheless retains a pivotal role in diagnosing tropical GIT disease. This role entails evaluating endoscopic biopsies for any characteristic inflammatory pattern, identifying pathogens which may be present and excluding other look-alike pathologies. Recent advances in commercially available diagnostic modalities, including molecular techniques, have further broadened the scope of the histopathologist's armamentarium. This review outlines a practical pattern-based approach to diagnosing tropical GIT infections in endoscopic material, so as to assist pathologists less familiar with this spectrum of pathology.
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- 2018
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29. Early biotic stress detection in tomato (Solanum lycopersicum) by BVOC emissions.
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Kasal-Slavik T, Eschweiler J, Kleist E, Mumm R, Goldbach HE, Schouten A, and Wildt J
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- Animals, Aphids metabolism, Ascomycota metabolism, Botrytis metabolism, Solanum lycopersicum microbiology, Oxidative Stress, Volatile Organic Compounds chemistry, Solanum lycopersicum metabolism, Volatile Organic Compounds metabolism
- Abstract
We investigated impacts of early and mild biotic stress on Biogenic Volatile Organic Compounds (BVOC) emissions from tomato in order to test their potential for early (biotic) stress detection. Tomato plants were exposed to two common fungal pathogens, Botrytis cinerea and Oidium neolycopesici and the sap-sucking aphid Myzus persicae. Furthermore, plants were exposed to methyl jasmonate (MeJA) in order to identify BVOC emissions related to activation of jasmonic acid (JA) signalling pathway. These emissions where then used as a reference for identifying active JA signalling pathway in plants at early stages of biotic stress. After infection by the necrotrophic fungus B. cinerea, changes in BVOC emissions indicated that tomato plants had predominantly activated the jasmonic acid (JA) signalling pathway. The plants were able to modify their defence pathways in order to overcome fungal infection. When tomato plants were infected with the biotrophic fungus O. neolycopersici, only minor changes in BVOC emissions were observed with additional emissions of the sesquiterpene α-copaene. α-copaene emissions allowed the identification of general biotic stress in the plants, without pinpointing the actual triggered defence pathway. BVOC emissions during M. persicae attack had changed before the occurrence of visual symptoms. Despite low infestation rates, plants emitted methyl salicylate indicating activation of the SA-mediated defence pathway., (Copyright © 2017 Elsevier Ltd. All rights reserved.)
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- 2017
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30. CD14(+) macrophages that accumulate in the colon of African AIDS patients express pro-inflammatory cytokines and are responsive to lipopolysaccharide.
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Cassol E, Rossouw T, Malfeld S, Mahasha P, Slavik T, Seebregts C, Bond R, du Plessis J, Janssen C, Roskams T, Nevens F, Alfano M, Poli G, and van der Merwe SW
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- Acquired Immunodeficiency Syndrome immunology, Adult, Antigens, CD metabolism, Antigens, Differentiation, Myelomonocytic metabolism, Chemokines genetics, Chemokines metabolism, Coinfection pathology, Colon microbiology, Colon pathology, Cytokines genetics, Female, Flow Cytometry, Humans, Immunohistochemistry, Inflammation, Inflammatory Bowel Diseases pathology, Lipopolysaccharides toxicity, Macrophages drug effects, Macrophages metabolism, Male, Middle Aged, Mucous Membrane metabolism, RNA, Messenger metabolism, Th1 Cells immunology, Th1 Cells metabolism, Tumor Necrosis Factor-alpha, Acquired Immunodeficiency Syndrome pathology, Colon immunology, Cytokines metabolism, Lipopolysaccharide Receptors metabolism, Macrophages immunology
- Abstract
Background: Intestinal macrophages are key regulators of inflammatory responses to the gut microbiome and play a central role in maintaining tissue homeostasis and epithelial integrity. However, little is known about the role of these cells in HIV infection, a disease fuelled by intestinal inflammation, a loss of epithelial barrier function and increased microbial translocation (MT)., Methods: Phenotypic and functional characterization of intestinal macrophages was performed for 23 African AIDS patients with chronic diarrhea and/or weight loss and 11 HIV-negative Africans with and without inflammatory bowel disease (IBD). AIDS patients were treated with cotrimoxazole for the prevention of opportunistic infections (OIs). Macrophage phenotype was assessed by flow cytometry and immuno-histochemistry (IHC); production of proinflammatory mediators by IHC and Qiagen PCR Arrays; in vitro secretion of cytokines by the Bio-Plex Suspension Array System. Statistical analyses were performed using Spearman's correlation and Wilcoxon matched-pair tests. Results between groups were analyzed using the Kruskal-Wallis with Dunn's post-test and the Mann-Whitney U tests., Results: None of the study participants had evidence of enteric co-infections as assessed by stool analysis and histology. Compared to healthy HIV-negative controls, the colon of AIDS patients was highly inflamed with increased infiltration of inflammatory cells and increased mRNA expression of proinflammatory cytokine (tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IFN-γ, and IL-18), chemokines (chemokine (C-C motif) ligand (CCL)2 and chemokine (C-X-C) motif ligand (CXCL)10) and transcription factors (TNF receptor-associated factor (TRAF)6 and T-box (TXB)21). IHC revealed significant co-localization of TNF-α and IL-1β with CD68(+) cells. As in IBD, HIV was associated with a marked increase in macrophages expressing innate response receptors including CD14, the co-receptor for lipopolysaccharide (LPS). The frequency of CD14(+) macrophages correlated positively with plasma LPS, a marker of MT. Total unfractionated mucosal mononuclear cells (MMC) isolated from the colon of AIDS patients, but not MMC depleted of CD14(+) cells, secreted increased levels of proinflammatory cytokines ex vivo in response to LPS., Conclusions: Intestinal macrophages, in the absence of overt OIs, play an important role in driving persistent inflammation in HIV patients with late-stage disease and diarrhea. These results suggest intensified treatment strategies that target inflammatory processes in intestinal macrophages may be highly beneficial in restoring the epithelial barrier and limiting MT in HIV-infected patients.
- Published
- 2015
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31. Diagnosis and predictive molecular analysis of non-small-cell lung cancer in the Africa-Middle East region: challenges and strategies for improvement.
- Author
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Slavik T, Asselah F, Fakhruddin N, El Khodary A, Torjman F, Anis E, Quinn M, Khankan A, and Kerr KM
- Subjects
- Africa, Animals, Biomarkers, Tumor metabolism, Expert Testimony, Humans, Middle East, Pathology, Molecular methods, Precision Medicine, Predictive Value of Tests, Prognosis, Quality Improvement, Carcinoma, Non-Small-Cell Lung diagnosis, Lung Neoplasms diagnosis
- Abstract
The identification of tumor biomarkers provides information on the prognosis and guides the implementation of appropriate treatment in patients with many different cancer types. In non-small cell lung cancer (NSCLC), targeted treatment plans based on biomarker identification have already been used in the clinic. However, such predictive molecular testing is not currently a universally used practice. This is the case, in particular, in developing countries where lung cancer is increasingly prevalent. In September 2012 and November 2013, a committee of 16 lung cancer experts from Africa and the Middle East met to discuss key issues related to diagnosis and biomarker testing in NSCLC and the implementation of personalized medicine in the region. The committee identified current challenges for effective diagnosis and predictive analysis in Africa and the Middle East. Moreover, strategies to encourage the implementation of biomarker testing were discussed. A practical approach for the effective diagnosis and predictive molecular testing of NSCLC in these regions was derived. We present the key issues and recommendations arising from the meetings., (Copyright © 2014 Elsevier Inc. All rights reserved.)
- Published
- 2014
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32. Cronkhite–Canada syndrome six decades on: the many faces of an enigmatic disease.
- Author
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Slavik T and Montgomery EA
- Subjects
- Humans, Prognosis, Syndrome, Intestinal Mucosa pathology, Intestinal Polyposis pathology, Intestinal Polyps pathology, Stomach pathology
- Abstract
Cronkhite–Canada syndrome is a rare gastro-enterocolopathy of uncertain aetiology first described almost 60 years ago. It is characterised by diffuse gastrointestinal polyposis sparing only the oesophagus, ectodermal abnormalities and an unpredictable but often fatal clinical course. The disease may demonstrate extremely diverse clinical and endoscopic features, which often leads to a delay in diagnosis. A high index of suspicion and recognition of the characteristic histological findings frequently facilitate a correct diagnosis, but the distribution of the gastrointestinal pathology and its microscopic features may be atypical. The pathologist thus requires a thorough knowledge of both the typical and many atypical faces of this disease, for which various documented therapies often still prove ineffective. Close correlation with clinical findings, including any pertinent ectodermal abnormalities, and careful examination of biopsies derived from polypoid and endoscopically spared mucosa will ensure a timely and correct diagnosis in patients with this enigmatic syndrome.
- Published
- 2014
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33. Polymerase chain reaction amplifying mycobacterial DNA from aspirates obtained by endoscopic ultrasound allows accurate diagnosis of mycobacterial disease in HIV-positive patients with abdominal lymphadenopathy.
- Author
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Nieuwoudt M, Lameris R, Corcoran C, Rossouw TM, Slavik T, Du Plessis J, Omoshoro-Jones JA, Stivaktas P, Potgieter F, and Van der Merwe SW
- Subjects
- Abdomen, Adult, Biopsy, Fine-Needle, Cohort Studies, DNA, Female, Flow Cytometry methods, Humans, Male, Prospective Studies, Sensitivity and Specificity, Endosonography methods, HIV Infections complications, Lymphatic Diseases complications, Mycobacterium Infections complications, Mycobacterium Infections diagnosis, Polymerase Chain Reaction methods
- Abstract
Abdominal lymphadenopathy in human immunodeficiency virus (HIV) infection remains a diagnostic challenge. We performed a prospective cohort study by recruiting 31 symptomatic HIV + patients with abdominal lymphadenopathy and assessing the diagnostic yield of endoscopic ultrasound fine-needle aspiration (EUS-FNA). Mean age was 38 years; 52% were female; and mean CD4 count and viral load were 124 cells/μL and 4 log, respectively. EUS confirmed additional mediastinal nodes in 26%. The porta hepatis was the most common abdominal site. Aspirates obtained by EUS-FNA were subjected to cytology, culture and polymerase chain reaction (PCR) analysis. Mycobacterial infections were confirmed in 67.7%, and 31% had reactive lymphadenopathy. Cytology and culture had low sensitivity, whereas PCR identified 90% of mycobacterial infections. By combining the appearance of aspirates obtained by EUS-FNA and cytologic specimens, we developed a diagnostic algorithm to indicate when analysis with PCR would be useful. PCR performed on material obtained by EUS-FNA was highly accurate in confirming mycobacterial disease and determining genotypic drug resistance., (Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)
- Published
- 2014
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34. Duodenal gastrointestinal stromal tumor with epithelioid and neural features mimicking a primary pancreas head neuroendocrine tumor.
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Slavik T, du Plessis J, Sparaco A, and van der Merwe SW
- Subjects
- Anoctamin-1, Antigens, CD34 metabolism, Chloride Channels metabolism, Chromogranin A metabolism, Diagnosis, Differential, Duodenal Neoplasms metabolism, Epithelioid Cells metabolism, Epithelioid Cells pathology, Female, Gastrointestinal Stromal Tumors metabolism, Humans, Middle Aged, Neoplasm Proteins metabolism, Neuroendocrine Tumors metabolism, Neurons metabolism, Neurons pathology, Pancreatic Neoplasms metabolism, Proto-Oncogene Proteins c-kit metabolism, Duodenal Neoplasms diagnosis, Gastrointestinal Stromal Tumors diagnosis, Neuroendocrine Tumors diagnosis, Pancreatic Neoplasms diagnosis
- Published
- 2014
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35. Impaired CD4+ T-cell restoration in the small versus large intestine of HIV-1-positive South Africans receiving combination antiretroviral therapy.
- Author
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Cassol E, Malfeld S, Mahasha P, Bond R, Slavik T, Seebregts C, Poli G, Cassol S, van der Merwe SW, and Rossouw T
- Subjects
- Adult, Antiretroviral Therapy, Highly Active methods, Biopsy, CD8-Positive T-Lymphocytes immunology, Female, Flow Cytometry, Humans, Male, Middle Aged, South Africa, Treatment Outcome, Young Adult, Anti-Retroviral Agents therapeutic use, CD4-Positive T-Lymphocytes immunology, HIV Infections drug therapy, HIV Infections immunology, Intestinal Mucosa immunology, Intestine, Large immunology, Intestine, Small immunology
- Abstract
Background: Human immunodeficiency virus type 1 (HIV-1) infection is associated with a massive depletion of intestinal CD4(+) T cells that is only partially reversed by combination antiretroviral therapy (cART). Here, we assessed the ability of nucleoside reverse-transcriptase inhibitor/nonnucleoside reverse-transcriptase inhibitor treatment to restore the CD4(+) T-cell populations in the intestine of South African patients with AIDS., Methods: Thirty-eight patients with advanced HIV-1 infection who had chronic diarrhea (duration, >4 weeks) and/or unintentional weight loss (>10% decrease from baseline) of uncertain etiology were enrolled. Blood specimens were collected monthly, and gastrointestinal tract biopsy specimens were collected before cART initiation (from the duodenum, jejunum, ileum, and colon), 3 months after cART initiation (from the duodenum), and 6 months after cART initiation (from the duodenum and colon). CD4(+), CD8(+), and CD38(+)CD8(+) T cells were quantified by flow cytometry and immunohistochemistry analyses, and the HIV-1 RNA load was determined by the Nuclisens assay., Results: CD4(+) T-cell and HIV-1 RNA levels were significantly lower, whereas CD8(+) T-cell levels, including activated CD38(+)CD8(+) T cell levels, were higher in the duodenum and jejunum, compared with the colon. After 6 months of cART, a significant but incomplete recovery of CD4(+) T cells was detected in the colon and peripheral blood but not in the duodenum. Failed restoration of the CD4(+) T-cell count in the duodenum was associated with nonspecific enteritis and CD8(+) T-cell activation., Conclusions: Strategies that target inflammation and immune activation in the small intestine may be required to expedite CD4(+) T-cell recovery and improve therapeutic outcomes.
- Published
- 2013
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36. Activated intestinal macrophages in patients with cirrhosis release NO and IL-6 that may disrupt intestinal barrier function.
- Author
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Du Plessis J, Vanheel H, Janssen CE, Roos L, Slavik T, Stivaktas PI, Nieuwoudt M, van Wyk SG, Vieira W, Pretorius E, Beukes M, Farré R, Tack J, Laleman W, Fevery J, Nevens F, Roskams T, and Van der Merwe SW
- Subjects
- Aged, Female, Humans, Intestinal Mucosa metabolism, Lipopolysaccharide Receptors analysis, Macrophages metabolism, Male, Middle Aged, Nitric Oxide Synthase Type II metabolism, Permeability, Interleukin-6 metabolism, Intestines immunology, Liver Cirrhosis immunology, Macrophage Activation, Macrophages immunology, Nitric Oxide metabolism
- Abstract
Background & Aims: Bacterial infections commonly occur in decompensated cirrhosis resulting from bacterial translocation from the intestine. We studied the role of intestinal macrophages and the epithelial barrier in cirrhosis., Methods: Forty-four patients with NASH/ASH cirrhosis (decompensated n=29, compensated n=15) and nineteen controls undergoing endoscopy were recruited. Serum was obtained and LPS and LBP levels determined. Intestinal macrophages were characterized by flow cytometry, immunohistochemistry, and nitric oxide (NO) production measured in supernatant of cultured duodenal samples. Quantitative RT-PCR was performed on duodenal biopsies assessing 84 inflammatory genes. Protein levels of cytokines/chemokines were assessed in serum and supernatant. The duodenal wall was assessed by electron microscopy, tight junction protein expression determined by RT-PCR, immunohistochemistry, and Western blot and, functional analysis performed by transepithelial resistance measurement and permeability studies., Results: Increased plasma LPS, LBP levels and higher numbers of duodenal CD33(+)/CD14(+)/Trem-1(+) macrophages, synthesizing iNOS and secreting NO were present in decompensated cirrhosis. Upregulation of IL-8, CCL2, CCL13 at the transcriptional level, and increased IL-8, and IL-6 were detected in supernatant and serum in cirrhosis. IL-6 and IL-8 co-localised with iNOS(+) and CD68(+), but not with CD11c(+) cells. Electron microscopy demonstrated an intact epithelial barrier. Increased Claudin-2 was detected by Western blot and immunohistochemistry, while decreased transepithelial resistance and increased duodenal permeability were detected in decompensated cirrhosis., Conclusions: Our study shows the presence of activated CD14(+)Trem-1(+)iNOS(+) intestinal macrophages, releasing IL-6, NO, and increased intestinal permeability in patients with cirrhosis, suggesting that these cells may produce factors capable of enhancing permeability to bacterial products., (Copyright © 2013. Published by Elsevier B.V.)
- Published
- 2013
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37. Human immunodeficiency virus-related gastrointestinal pathology: a southern Africa perspective with review of the literature (part 1: infections).
- Author
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Slavik T
- Subjects
- Africa, Southern, Bacterial Infections complications, Humans, Immunocompromised Host, Mycoses complications, Parasitic Diseases complications, AIDS-Related Opportunistic Infections complications, Acquired Immunodeficiency Syndrome complications, Gastrointestinal Diseases complications, Gastrointestinal Tract pathology
- Abstract
Context: Human immunodeficiency virus infection is rife in sub-Saharan Africa and in southern Africa in particular. Despite the increasing availability of antiretroviral therapy in this region, opportunistic infections remain common and frequently involve the gastrointestinal tract., Objective: To review the histopathologic findings and distinguishing features of human immunodeficiency virus-associated gastrointestinal infections in southern Africa and relate those findings to the documented international literature., Data Sources: The available literature on this topic was reviewed and supplemented with personal experience in a private histopathology practice in South Africa., Conclusions: In southern Africa, the range of gastrointestinal, opportunistic infectious pathology in human immunodeficiency virus afflicted patients is diverse and includes viral, bacterial, fungal, and parasitic infections. This infectious pathology is sometimes a manifestation of systemic disease. In profoundly immunocompromised patients, unusual histologic features, involvement of uncommon gastrointestinal tract sites, and more than one pathogen may be seen.
- Published
- 2012
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38. Human immunodeficiency virus-related gastrointestinal pathology: a southern Africa perspective with review of the literature (part 2: neoplasms and noninfectious disorders).
- Author
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Slavik T
- Subjects
- Africa, Southern, Esophageal Diseases complications, Humans, Immune Reconstitution Inflammatory Syndrome complications, Ulcer complications, AIDS-Related Opportunistic Infections complications, Acquired Immunodeficiency Syndrome complications, Gastrointestinal Neoplasms complications, Gastrointestinal Tract pathology
- Abstract
Context: Human immunodeficiency virus (HIV) infection is rife in sub-Saharan Africa and in southern Africa in particular. Despite the increasing availability of antiretroviral therapy in this region, HIV-associated neoplasms remain common and frequently involve the gastrointestinal tract, which may also demonstrate other noninfectious, HIV-related pathology., Objective: To review the histopathologic findings and distinguishing features of neoplastic and noninfectious, HIV-associated gastrointestinal disorders in southern Africa and relate those findings to the documented international literature., Data Sources: The available literature on this topic was reviewed and supplemented with personal experience in a private histopathology practice in South Africa., Conclusions: In southern Africa, a diverse range of HIV-related neoplasms and noninfectious gastrointestinal disorders is seen, but published data for the region are scarce. The gastrointestinal disorders include drug-associated pathology, gastrointestinal manifestations of the immune reconstitution inflammatory syndrome, idiopathic chronic esophageal ulceration, and the controversial entity of HIV enteropathy.
- Published
- 2012
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39. Toothy craniopharyngioma: a literature review and case report of craniopharyngioma with extensive odontogenic differentiation and tooth formation.
- Author
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Muller C, Adroos N, Lockhat Z, Slavik T, and Kruger H
- Subjects
- Child, Preschool, Craniopharyngioma surgery, Diagnosis, Differential, Humans, Pituitary Neoplasms surgery, Teratoma pathology, Cell Differentiation, Craniopharyngioma pathology, Pituitary Neoplasms pathology, Tooth pathology
- Published
- 2011
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40. Infantile fibrosarcoma of the ileum presenting with congenital bowel obstruction.
- Author
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van Niekerk ML, Nel WA, and Slavik T
- Subjects
- Fibrosarcoma surgery, Humans, Ileal Diseases pathology, Ileal Diseases surgery, Ileal Neoplasms surgery, Ileum pathology, Infant, Newborn, Intestinal Obstruction surgery, Male, Rare Diseases, Fibrosarcoma pathology, Ileal Neoplasms pathology, Intestinal Obstruction pathology
- Published
- 2010
- Full Text
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41. Primary chondroid melanoma of the nasal skin: a rare melanoma variant at a previously undocumented site.
- Author
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Slavik T, Hannah M, and Schroder RA
- Subjects
- Carcinoma, Basal Cell pathology, Diagnosis, Differential, Female, Humans, Melanoma metabolism, Middle Aged, Skin Neoplasms metabolism, Melanoma pathology, Nose pathology, Skin Neoplasms pathology
- Abstract
Heterologous differentiation is exceedingly rare in melanoma. Only four cases of melanoma demonstrating exclusive cartilaginous differentiation have been documented, all having occurred on the lower extremity. We report a chondroid melanoma involving the nasal skin and presenting clinically as a basal cell carcinoma. Both Melan-A and microphthalmia transcription factor protein immunoperoxidase stains were positive in our case, demonstrating the potential utility of these two stains in chondroid melanoma. We also provide a succinct review of the literature on this rare melanoma variant.
- Published
- 2007
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42. DNA methylation pattern in pig in vivo produced embryos.
- Author
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Fulka J, Fulka H, Slavik T, Okada K, and Fulka J Jr
- Subjects
- Animals, Blastocyst metabolism, Chromatin metabolism, Embryo, Mammalian embryology, Female, Swine, Zygote metabolism, DNA Methylation, Embryo, Mammalian metabolism
- Abstract
DNA methylation/demethylation pattern, determined by 5-methylcytosine (5-MeC) immunostaining, was evaluated in porcine "in vivo" produced embryos from zygote up to the blastocyst stage. In one-cell stage embryos, only the maternal pronucleus showed a positive labeling whilst the paternal pronucleus showed almost no labeling. The intensity of labeling is high until the late morula stage. Blastocysts containing less than 100 cells showed the same intensity of labeling in both the inner cell mass (ICM) nuclei and the trophectodermal (TE) cell nuclei. Interestingly, with further cell multiplication, cells of the ICM became more intensively labeled when compared to TE cells. This distinct methylation pattern is even more profound in blastocysts containing about 200-300 cells and is not caused by the difference in the cell volume of ICM and TE cells.
- Published
- 2006
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43. Effect of rapamycin on hepatic osteodystrophy in rats with portasystemic shunting.
- Author
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van der Merwe SW, Conradie MM, Bond R, Olivier BJ, Fritz E, Nieuwoudt M, Delport R, Slavik T, Engelbrecht G, Kahn D, Shephard EG, Kotze MJ, de Villiers NP, and Hough S
- Subjects
- Animals, Body Mass Index, Bone Density physiology, Bone Resorption pathology, CD8-Positive T-Lymphocytes drug effects, CD8-Positive T-Lymphocytes physiology, Carrier Proteins genetics, Cytokines blood, Cytokines metabolism, Eating physiology, Gene Expression Regulation, Lymphocyte Activation drug effects, Lymphocyte Activation physiology, Male, Membrane Glycoproteins genetics, Osteoclasts pathology, Osteoclasts physiology, Osteoporosis etiology, Osteoporosis metabolism, RANK Ligand, Rats, Rats, Sprague-Dawley, Tumor Necrosis Factor-alpha analysis, Tumor Necrosis Factor-alpha genetics, Tumor Necrosis Factor-alpha metabolism, Bone Resorption etiology, Bone Resorption physiopathology, Carrier Proteins metabolism, Immunosuppressive Agents pharmacology, Membrane Glycoproteins metabolism, Osteoclasts drug effects, Osteoporosis prevention & control, Portasystemic Shunt, Surgical adverse effects, Sirolimus pharmacology
- Abstract
Aim: To study if T-cell activation related to portasystemic shunting causes osteoclast-mediated bone loss through RANKL-dependent pathways. We also investigated if T-cell inhibition using rapamycin would protect against bone loss in rats., Methods: Portasystemic shunting was performed in male Sprague-Dawley rats and rapamycin 0.1 mg/kg was administered for 15 wk by gavage. Rats received powderized chow and supplemental feeds to prevent the effects of malnutrition on bone composition. Weight gain and growth was restored after surgery in shunted animals. At termination, biochemical parameters of bone turnover and quantitative bone histology were assessed. Markers of T-cell activation, inflammatory cytokine production, and RANKL-dependent pathways were measured. In addition, the roles of IGF-1 and hypogonadism were investigated., Results: Portasystemic shunting caused low turnover osteoporosis that was RANKL independent. Bone resorbing cytokine levels, including IL-1, IL-6 and TNFalpha, were not increased in serum and TNFalpha and RANKL expression were not upregulated in PBMC. Portasystemic shunting increased the circulating CD8+ T-cell population. Rapamycin decreased the circulating CD8+ T-cell population, increased CD8+ CD25+ T-regulatory cell population and improved all parameters of bone turnover., Conclusion: Osteoporosis caused by portasystemic shunting may be partially ameliorated by rapamycin in the rat model of hepatic osteodystrophy.
- Published
- 2006
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44. Incidence of Helicobacter felis and the effect of coinfection with Helicobacter pylori on the gastric mucosa in the African population.
- Author
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Fritz EL, Slavik T, Delport W, Olivier B, and van der Merwe SW
- Subjects
- Adolescent, Adult, Bacterial Proteins genetics, Base Sequence, Child, Child, Preschool, DNA, Bacterial genetics, Female, Genes, Bacterial, Helicobacter Infections epidemiology, Helicobacter Infections transmission, Humans, Male, Membrane Transport Proteins genetics, Pedigree, South Africa epidemiology, Gastric Mucosa pathology, Helicobacter Infections microbiology, Helicobacter Infections pathology, Helicobacter felis genetics, Helicobacter felis isolation & purification, Helicobacter felis pathogenicity, Helicobacter pylori genetics, Helicobacter pylori isolation & purification, Helicobacter pylori pathogenicity
- Abstract
Helicobacter pylori and Helicobacter felis are two of the Helicobacter spp. that infect humans. H. pylori has been linked to significant gastric pathology. Coinfection with Helicobacter spp. may influence infectious burden, pathogenesis, and antibiotic resistance; however, this has not been studied. The aims of this study were to identify the incidence of H. felis and to analyze the effects of coinfection with both organisms on gastric pathology in a well-characterized South African population. Biopsy samples from the gastric corpora and antra of volunteers (n = 90) were subjected to histological examination and PCR for the identification of H. pylori and H. felis. We further investigated the effect of global strain type on the occurrence of precursor lesions by assigning nucleotide sequences derived from PCR amplification of three genes to global groupings (ancestral Africa1, ancestral Africa2, ancestral Europe, ancestral Asia, and mixed). H. pylori was detected in 75 (83.3%), H. felis in 23 (25.6%), and coinfection in 21 (23.3%) of the volunteers by PCR. H. felis was randomly distributed among adults and children but clustered within families, suggesting intrafamilial transmission. Analysis of histopathology scores revealed no differences in atrophy, activity, and helicobacter density between H. felis-positive and H. felis-negative volunteers. H. pylori substrains common to southern Africa showed no differences in inflammation or atrophy scores. The incidences of H. felis and coinfection with H. pylori in the African population are high. H. felis infection, however, does not influence specific gastric pathology in this population.
- Published
- 2006
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45. Absence of Helicobacter pylori within the oral cavities of members of a healthy South African community.
- Author
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Olivier BJ, Bond RP, van Zyl WB, Delport M, Slavik T, Ziady C, Terhaar Sive Droste JS, Lastovica A, and van der Merwe SW
- Subjects
- Adolescent, Adult, Aged, Biopsy, Child, Child, Preschool, Dental Plaque microbiology, Female, Helicobacter Infections epidemiology, Helicobacter Infections microbiology, Humans, Male, Middle Aged, Polymerase Chain Reaction methods, Prevalence, South Africa epidemiology, Stomach microbiology, Helicobacter Infections transmission, Helicobacter pylori isolation & purification, Mouth microbiology, Rural Population
- Abstract
Our study aimed to evaluate the oral cavity as a reservoir from where Helicobacter pylori may be transmitted. Histology and PCR amplification were performed. Eighty-four percent of the stomach biopsies tested positive; however, H. pylori was not detected in dental samples, indicating the absence of H. pylori within the oral cavity.
- Published
- 2006
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46. Antitumor activity and other biological actions of oligomers of ribonuclease A.
- Author
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Matousek J, Gotte G, Pouckova P, Soucek J, Slavik T, Vottariello F, and Libonati M
- Subjects
- Animals, Cattle, Cell Division drug effects, Dimerization, Embryo, Mammalian drug effects, Female, Humans, Melanoma drug therapy, Mice, Protein Conformation, Ribonuclease, Pancreatic isolation & purification, Spermatogenesis drug effects, Structure-Activity Relationship, Transplantation, Heterologous, Tumor Cells, Cultured, Antineoplastic Agents pharmacology, Peptide Fragments pharmacology, Ribonuclease, Pancreatic chemistry, Ribonuclease, Pancreatic pharmacology
- Abstract
Dimers, trimers, and tetramers of bovine ribonuclease A, obtained by lyophilization of the enzyme from 40% acetic acid solutions, were purified and isolated by cation exchange chromatography. The two conformers constituting each aggregated species were assayed for their antitumor, aspermatogenic, or embryotoxic activities in comparison with monomeric RNase A and bovine seminal RNase, which is dimeric in nature. The antitumor action was tested in vitro on ML-2 (human myeloid leukemia) and HL-60 (human myeloid cell line) cells and in vivo on the growth of human non-pigmented melanoma (line UB900518) transplanted subcutaneously in nude mice. RNase A oligomers display a definite antitumor activity that increases as a function of the size of the oligomers. On ML-2 and HL-60 cells, dimers and trimers generally show a lower activity than bovine seminal RNase; the activity of tetramers, instead, is similar to or higher than that of the seminal enzyme. The growth of human melanoma in nude mice is inhibited by RNase A oligomers in the order dimers < trimers < tetramers. The action of the two tetramers is very strong, blocking almost completely the growth of melanoma. RNase A dimers, trimers, and tetramers display aspermatogenic effects similar to those of bovine seminal RNase, but, contrarily, they do not show any embryotoxic activity.
- Published
- 2003
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47. Bovine seminal ribonuclease attached to nanoparticles made of polylactic acid kills leukemia and lymphoma cell lines in vitro.
- Author
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Michaelis M, Matousek J, Vogel JU, Slavik T, Langer K, Cinatl J, Kreuter J, Schwabe D, and Cinatl J
- Subjects
- Animals, Apoptosis drug effects, Cattle, Cell Division drug effects, Dose-Response Relationship, Drug, Drug Carriers, Fibroblasts drug effects, Humans, Lactic Acid, Male, Mice, Mice, Inbred ICR, Microspheres, Polyesters, Polymers, Spermatozoa drug effects, Testis drug effects, Tetrazolium Salts metabolism, Thiazoles metabolism, Antineoplastic Agents pharmacology, Endoribonucleases pharmacology, Leukemia drug therapy, Lymphoma drug therapy, Tumor Cells, Cultured drug effects
- Abstract
Bovine seminal ribonuclease (BS-RNase) is a protein with a number of biological effects. It shows antitumoral, aspermatogenic, antiembryonic, immunosuppressive and antiviral properties. The cytotoxic effects appear to be specific for tumor cells as non-malignant cells seem to be unaffected in vitro. Unfortunately, the in vivo application of BS-RNase so far was successful only when it was administered intratumorally. Therefore, the objective of the present investigation was to improve the properties of BS-RNase by attachment to nanoparticles made of polylactic acid (PLA-NP) using an adsorption method. This preparation was tested in vitro against leukemia (MOLT-4) and lymphoma (H9) cell lines sensitive and resistant to cytarabine. No difference between the nanoparticle preparation and pure BS-RNase was found in these tests. To examine the in vivo effects, the preparations were tested for their aspermatogenic and antiembryonal efficacy compared to the pure BS-RNase as a rapid test for antitumoral activity. The aspermatogenic and antiembryonal effects were enhanced by the nanoparticle preparation. Consequently, BS-RNase loaded adsorptively to PLA-NP holds promise for the in vivo use as an antitumoral agent. Further research will investigate the efficacy of this preparations in an in vivo tumor model.
- Published
- 2000
- Full Text
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48. Solitary fibrous tumor of the meninges occurring after irradiation of a mixed germ cell tumor of the pineal gland.
- Author
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Slavik T, Bentley RC, Gray L, Fuchs HE, and McLendon RE
- Subjects
- Child, Combined Modality Therapy, Diagnosis, Differential, Endocrine Gland Neoplasms radiotherapy, Germinoma radiotherapy, Humans, Immunohistochemistry, Magnetic Resonance Imaging, Male, Antineoplastic Agents therapeutic use, Endocrine Gland Neoplasms therapy, Germinoma therapy, Meningeal Neoplasms etiology, Pineal Gland
- Abstract
Twenty-nine months after surgery, irradiation, and systemic chemotherapy for a pineal mixed germ cell tumor, an 11-year-old Caucasian male developed a 3 cm dural based nodule in the occipital lobe that proved to be a solitary fibrous tumor by immunohistochemical and ultrastructural examination. Differential diagnosis included fibrous meningioma, neurofibroma, Schwannoma, cranial fasciitis of infancy, and solitary fibrous tumor. A Masson trichrome stain revealed a prominent collagenous stroma and reticulin staining exhibited strong pericellular positivity. Immunohistochemical staining demonstrated diffuse vimentin and focal CD34 positivity of tumor cells. Ultrastructural examination revealed fibroblastic differentiation. These features are consistent with solitary fibrous tumor. Although we favor a radiation-induced origin for the neoplasm, alternative explanations for the tumor's origin include cerebrospinal fluid spread from the original germ cell tumor or a de novo neoplasm.
- Published
- 1998
49. HIV-1 infection in patients with tuberculous lymphadenitis.
- Author
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Slavik T, Wolfaardt M, van Zyl H, and Simson IW
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Child, Child, Preschool, Cross-Sectional Studies, Female, HIV Seropositivity epidemiology, Humans, Male, Middle Aged, Polymerase Chain Reaction, Retrospective Studies, HIV Infections epidemiology, HIV Seroprevalence, HIV-1, Tuberculosis, Lymph Node complications
- Published
- 1996
50. The use of transvaginal ultrasonography in the diagnosis of ectopic pregnancy.
- Author
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Timor-Tritsch IE, Yeh MN, Peisner DB, Lesser KB, and Slavik TA
- Subjects
- Diagnosis, Differential, Female, Humans, Laparotomy, Ovarian Cysts diagnosis, Pregnancy, Pregnancy, Ectopic surgery, Sensitivity and Specificity, Ultrasonography standards, Vagina, Pregnancy, Ectopic diagnosis, Ultrasonography methods
- Abstract
Despite advances in diagnosis made by the introduction of serum beta-subunit of human chorionic gonadotropin determinations and transabdominal ultrasonography, ectopic gestations still present a major diagnostic challenge. The increased resolution of the transvaginally introduced high-frequency ultrasound transducer probes seems to solve this diagnostic problem. In this study 145 patients were referred for ultrasonographic workup because of a suspected ectopic gestation. In 38 patients a diagnosis could be made with classical transabdominal scanning. One hundred seventeen patients required additional transvaginal scanning with a 5.0 and a 6.5 MHz probe. In 98 patients a diagnosis was made during the first transvaginal scan; nine patients were rescanned within 3 days for the final diagnosis. In 56 patients, ectopic pregnancy was successfully ruled out by transvaginal scanning. Thirty-nine ectopic pregnancies were diagnosed. Only one false-positive identification was made. The sensitivity of diagnosing ectopic pregnancy by high-frequency transvaginal sonography was 100%; the specificity was 98.2%. The positive predictive value of this method was 98%, and the negative predictive value was 100%. The rate of the beating fetal heart was seen in the tube (23%). The high number of unruptured tubal pregnancies in this series (66%) suggests the possibility of an early diagnosis that may have therapeutic implications. The use of higher-frequency transvaginal transducer probes improves the diagnosis of the ectopic gestation.
- Published
- 1989
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