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J W Schneider

Publications and source records attributed to J W Schneider.

At least 19 recordsLinked to original sources
PubMed2006

Fibroblastic rheumatism.

We report the first known South African case of fibroblastic rheumatism, a rare dermatoarthropathy. Our patient presented with the typical clinical features of a sudden-onset, erosive polyarthritis with cutaneous nodules and sclerodactyly. Significant functional loss occurred within a period of 3 to 4 months. X-rays of the hands showed a single erosion, whereas magnetic resonance imaging showed further erosions as well as soft tissue and synovial enhancement. The unique histologic findings of fibroblastic proliferation, thickened collagen, and dermal fibrosis confirmed the diagnosis of fibroblastic rheumatism. Our patient was treated with a combination of methotrexate and oral prednisolone with subsequent resolution of her synovitis/arthritis and no further progression of her sclerodactyly and associated functional loss. The course of fibroblastic rheumatism is known to vary and although multiple therapeutic options have been tried, the question remains whether any of the therapies alters the natural course of the disease. However, considering the probable role of lymphocytes and fibrogenic cytokines, an increased awareness with early diagnosis and treatment in the initial inflammatory stage may prevent the development of incapacitating joint sequelae.

Arthralgia↗
PubMed2004

A new type of minocycline-induced cutaneous hyperpigmentation.

Pigmentary disorders are recognized adverse effects of the semi-synthetic tetracycline derivative antibiotic, minocycline. Three distinct types of minocycline-induced cutaneous pigmentation have been described. Type I, blue-black pigmentation confined to sites of scarring or inflammation on the face; Type II, blue-grey circumscribed pigmentation of normal skin of the lower legs and forearms; and Type III, diffuse muddy brown pigmentation of normal skin accentuated in sun-exposed areas. We report two patients with acne vulgaris with a fourth type of minocycline-induced cutaneous pigmentation. They presented with circumscribed blue-grey pigmentation within acne scars confined to the back. Histology showed pigment within dendritic cells, and extracellularly throughout the dermis. Histochemistry identified a calcium containing melanin-like substance. Iron was absent. Immunohistochemistry confirmed some pigment-containing cells to be macrophages. Electron microscopy demonstrated electron-dense granules, free and membrane-bound, within macrophages and fibroblast-like cells. Energy-dispersive X-ray analysis confirmed the presence of calcium. Iron was absent. This fourth type of cutaneous minocycline hyperpigmentation may be a variant of Type I, but based on clinical, pathological and microanalytical differences, appears to be a new entity. The pigment may be a drug metabolite-protein complex chelated with calcium, or an insoluble minocycline-melanin complex. We propose a classification of cutaneous minocycline pigmentation based on clinico-pathological criteria.

Acne Vulgaris↗
PubMed2003

Diagnostic aspects of cervical lymphadenopathy in children in the developing world: a study of 1,877 surgical specimens.

Chronic cervical lymphadenopathy is a common clinical problem frequently requiring surgical biopsy. To evaluate the characteristics of surgically excised cervical lymph nodes (LN) in children in a developing country, we studied 1,332 children less than 15 years old (1,877 surgically removed cervical LNs) over a 23-year period (1976-1999). Indications for biopsy included failure to respond to antibiotic therapy, rapid increase in size, hard, matted LNs in the preauricular, supraclavicular, and posterior triangle of the neck, and difficulty in diagnosis. Clinical and pathological characteristics investigated included age, malignancy, and granulomatous disease such as tuberculosis (tbc). The mean age was 7 years (tbc 5.8/neoplastic disease 8.5 years). Twenty LNs (1.5%) were histologically normal. There were 637 (47.8%) with nonspecific reactive lymphoid hyperplasia and 484 with chronic granulomatous changes (36.3%). Tuberculous lymphadenitis was confirmed in 332 of these (25%). In 181 (54.5%) Mycobacterium tuberculosis was cultured and a further 149 had acid-fast bacilli. Other granulomatous diseases identified included sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfmann disease) (3), syphilis (4), yaws (2), and toxoplasmosis (1). No mycobacteria other than M. tuberculosis were encountered. More than two-thirds (108) of 154 patients with neoplastic LN involvement had a lymphoma; in a further 10 lymphadenopathy was associated with leukemia. Pyogenic organisms were identified in 32, and 5 were positive for human immunodeficiency virus, 1 of whom had Kaposi's sarcoma. A second pathology was identified in 18 of the 637 cases of reactive lymphoid hyperplasia (3 with tuberculosis); in 15 (1.3%) a diagnosis of lymphoma was made from other sites (pleural fluid, etc.) within 6 months of initial biopsy. This represents a diagnostically difficult subgroup requiring further investigation. Chronic lymphadenopathy in children in developing countries has a high incidence of infective causes, including a significant incidence of M. tuberculosis. The incidence of serious pathology in more than one-half of the cervical LNs examined justifies aggressive surgical investigation.

Biopsy, Needle↗
PubMed2002

Non-familial visceral myopathy: clinical and pathologic features of degenerative leiomyopathy.

Degenerative leiomyopathy (DL) is a distinctive form of acquired degenerative visceral myopathy of uncertain etiology that occurs largely in Africa and results in intestinal pseudo-obstruction (IP). In this review of 39 patients from the Western Cape region of South Africa, the mean age at presentation was 9.5 years (range 6 months to 16 years). Characteristic clinical features included a chronic, insidious history of repeated attacks of abdominal distension, abdominal pain, and vomiting. Marked gaseous distension with atony and IP, especially of the colon, was noted on X-ray films. Megacolon was the most common radiologic feature, but pseudo-obstruction extended proximally into the small intestine in some patients with advanced disease. In the majority of cases the condition was progressive and eventually affected the entire gastrointestinal (GI) tract.

Abdominal Pain↗
PubMed2002

Unusual variations of gastrointestinal smooth muscle abnormalities associated with chronic intestinal pseudo-obstruction.

The clinicopathological spectrum of gastrointestinal (GI) smooth-muscle abnormalities associated with chronic intestinal pseudo-obstruction (CIPO) includes numerous heterogeneous conditions that are often ill-defined and poorly understood. Primary GI smooth-muscle abnormalities include familial and sporadic forms. Secondary involvement of GI smooth-muscle may result from associated GI and systemic conditions, but is less frequent than in adults. This study documents the clinicopathological findings observed in 12 South African patients with unusual forms of visceral smooth-muscle abnormalities not conforming to the diagnostic criteria of known primary visceral myopathies at the Tygerberg and Red Cross Childrens' Hospitals over a 14-year period (July 1985 through January 1999). Congenital muscle defects occurred in 5 patients where layers of bowel-wall muscle were absent or attenuated. Idiopathic fibrosis and ultrastructural features of perinuclear and mitochondrial vacuolisation were noted in 2 patients. A 21-year-old female with long-standing pseudo-obstruction demonstrated diminished immunohistochemical expression of enteric alpha-smooth-muscle actin without associated muscular degeneration or fibrosis. A secondary complication of dermatomyositis (bowel perforation) occurred twice in 1 patient. In 3 further patients (1 each with anorectal malformation, long-segment Hirschsprung's disease, and intestinal neuronal dysplasia), muscle fibrosis appeared during progression of the pre-existing disease. Visceral myopathies are poorly understood conditions that may present with CIPO. Unusual variations occur that do not conform to the usual recognised histological patterns. Secondary involvement may also be more common than anticipated in children. The challenge to further understanding these uncommon conditions lies in timely diagnosis and identification of early, subtle signs. Optimal and extensive application of various diagnostic modalities, including the development of new diagnostic tools, is of considerable importance in identifying hitherto unexplained CIPO due to GI smooth-muscle abnormalities.

Adolescent↗
PubMed2001

Cardiotoxicity in signal transduction therapeutics: erbB2 antibodies and the heart.

Cardiotoxicity is a common and potentially devastating side effect of antineoplastic drug therapy. This empiric observation is seen as paradoxical given that the cardiomyocyte is considered to be a terminally differentiated cell. Despite the fact that these cells do not divide after birth, adult cardiomyocytes may become "innocent bystander" targets of anticancer drugs designed to interfere with cell signaling pathways in rapidly proliferating cells. In breast cancer clinical trials, treatment with the erbB2 receptor antibody trastuzumab combined with anthracyclines has been associated with an increased risk for the development of cardiac pump failure. Trastuzumab/anthracycline cardiomyopathy may be the first clinically significant cardiotoxicity to emerge from signal transduction therapeutics. The erbB2 receptor tyrosine kinase is known to have a critical role in cardiac development. In addition, erbB2 is thought to participate in an important pathway for growth, repair, and survival of adult cardiomyocytes as part of a signaling network that involves neuregulins and the neuregulin receptor erbB4. However, erbB2 levels in the adult heart are low when compared with the levels found in erbB2-overexpressing breast cancer cells that are the intended targets of trastuzumab therapy. Thus, trastuzumab-associated cardiotoxicity must be explained by some alternative mechanism. After confirming that trastuzumab is capable of inducing tyrosine phosphorylation of the human cardiomyocyte erbB2 protein, a novel system for culturing human myocardium was developed in our laboratory. We used this system to study the effects of trastuzumab on human cardiomyocytes in vitro and observed trastuzumab-induced structural and functional changes in human cardiomyocytes that were at least partially reversible with the addition of recombinant neuregulins. The results obtained in these experiments support a direct action of trastuzumab on human cardiomyocytes. In addition, these data provide insight regarding potential molecular mechanisms. Most importantly, these data draw attention to the inherent risk of cardiotoxicity associated with a newly emerging class of antineoplastic drugs that interfere with signal transduction pathways.

Animals↗
PubMed2001

Health-related quality of life and functional outcome measures for children with cerebral palsy.

The aim of this study was to examine measures of health-related quality of life (HRQL) in children with cerebral palsy (CP) by comparing scores of a generic HRQL measure, the Child Health Questionnaire (CHQ); a disease-specific HRQL measure for children with CP, the Caregiver Questionnaire (CQ); and a pediatric functional measure, the Wee-Functional Independence Measure (WeeFIM). Participants included 30 caregivers of children with CP. The caregivers' children were a mean age of 8 years 6 months (17 females, 13 males). The ethnic origin of the children was 18 African-American, 8 white, 3 Hispanic, and 1 Middle Eastern. Significant correlations were found between the CQ and WeeFIM total and subscale scores (r=0.388 to 0.641). There was no correlation between the CHQ and CQ total summary scores, but significant correlations were found between the CHQ subscales related to parent time and family cohesion and the CQ total and subscale scores (r=0.386 to 0.481). The lack of correlation between the CHQ and WeeFIM indicates HRQL and function are different constructs that cannot be inferred from each other. The fair relationship found between the CQ and WeeFIM suggests that the constructs measured in these two assessments overlap. The lack of correlation between the total summary scores of the CHQ and CQ suggests the CQ may be a more specific measure of HRQL for this population that reflects the impact of the child's condition on the caregiver.

Adolescent↗
PubMed2001

Clinicopathological features of Meckel's diverticula in 32 patients, with emphasis on the presence of Helicobacter pylori.

Meckel's diverticula (MD) with areas of gastric heterotopia (metaplasia) are more likely to become symptomatic than those that contain mucosa of purely an intestinal type. Helicobacter pylori has been associated with the pathogenesis of various diseases. The aim of the study was to evaluate whether H. pylori could be identified within metaplastic gastric mucosa in MD. A retrospective evaluation of the histopathological features and the clinical presentation of patients with MD was undertaken. The study group included 32 cases (20 paediatric and 12 adults). The commonest modes of presentation were acute pain (25%), obstruction (19%), bleeding (12.5%) and hernias (9%). On histological examination, heterotopic gastric mucosa was noted to be present in 12 cases. Of these, 3 specimens were noted to have H. pylori organisms present using a specific immunostaining technique. Two patients had concurrent gastric biopsies; one stained positively for H. pylori but the second (1 mm biopsy) was rapid urease-test positive only. In conclusion, the study provides strong evidence that H. pylori may colonise heterotopic gastric mucosa in a minority of MD. H. pylori is apparently not involved in the pathogenesis of most cases of complicated MD. Nonetheless, all 3 patients who had evidence of H. pylori were symptomatic.

Adolescent↗
PubMed2000

Elevated tissue immunoglobulins in Hirschsprung's disease--indication of early immunologic response.

Hirschsprung's disease is of multifactorial origin including genetic as well as other region-specific neuroenvironmental factors as well as focal contact with the extracellular matrix. Immunological activity is elevated in patients with enterocolitis associated with Hirschsprung's disease suggesting an immunological role in HD. Increased expression of major histocompatibility complexes (MHC) class II antigens and ICAM-1 in the aganglionic segments of bowel further strengthen this association and suggest early immunologic involvement. In this study, immunoglobulin activity was biochemically assessed in surgically resected specimens of 23 patients with Hirschsprung's disease in whom there was no clinical or histological evidence of enterocolitis. IgG and IgM were significantly increased in segments of bowel histologically identified as aganglionic or transitional zone, suggesting an area of maximal immunological activity in the transitional zone. The lack of an increase in IgA immunoglobulin activity in the same bowel segments suggests that IgA response may be related to associated enterocolitis in HD. Elevated tissue IgG and IgM levels were observed in 5 neonates presenting within the first week of life and older patients did not have significantly higher immunoglobulin levels, suggesting that the immunological response was not part of an ongoing infection or progressive condition. Increased IgM in the neonatal period suggests an early immune response in Hirschsprung's disease and strengthens the hypothesis that the immune system may be involved in its pathogenesis. Possible causes include the effects of an antenatal infection or local microenvironmental influences on the differentiation or maturation of migrating neuroblasts of the enteric nervous system.

Age Factors↗
PubMed1999

Axillary lymph node involvement in stage III breast cancer: treatment implications.

BACKGROUND AND OBJECTIVES: The introduction of multimodal therapy has improved the prognosis in stage III breast cancer. A knowledge of the likely axillary lymph node status at presentation is important, both to plan surgical therapy to the axilla and to establish the effect of induction therapy on the axillary nodes. METHODS: The study involved a chart review of 114 patients with stage III breast cancer who were treated by modified radical mastectomy without prior systemic therapy. A standard method was used for axillary dissection and numbers and levels of pathologically involved lymph nodes were recorded. The incidence of lymph node metastases was correlated with tumour size, grade, and clinical T stage. The accuracy of clinical axillary staging and the relationship between level III invasion and the number of level I and II nodes invaded was also assessed. RESULTS: Overall, 96 of 114 (84%) patients had axillary nodal metastases, and 37 of 114 (32%) patients had level III metastases. Eighteen of 43 tumours (42%) 30 mm or less had level III metastases and 27% of larger tumours had level III metastases (6/25 31-49-mm tumours, and 12/42 50+-mm tumours). Of 98 gradable cancers, only 1 out of 10 well-differentiated tumours had level III metastases, but the rate in moderately and poorly differentiated tumours was 36% (19/53) and 37% (13/35), respectively. Clinical node staging was unreliable. A group of patients with a low likelihood of level III metastases who might benefit from an axillary procedure less than level III dissection could not be identified preoperatively. CONCLUSIONS: Patients with stage III breast cancer have a high incidence of level III axillary lymph node metastases. A subgroup with a low incidence of level III metastases could not be identified in this study. Until axillary downstaging has been convincingly demonstrated with induction therapy, a less than complete axillary procedure may leave the patient at high risk of axillary relapse.

Axilla↗
PubMed1999

Neuroblastoma in southern Africa: epidemiological features, prognostic factors and outcome.

We retrospectively analysed the epidemiological features and the importance of biochemical, histological and genetic parameters in predicting survival in 14 Namibian and 34 South African children treated for neuroblastoma (NB) from 1983 to 1997. Curative treatment consisted mainly of total (13%) or partial (44%) resection after chemotherapy (cyclophosphamide and doxorubicin x6 courses or carboplatin, etoposide, epirubicin and cyclophosphamide x6 courses). Localized radiotherapy with curative intent was given to 33% of patients. The male:female ratio was 0.9. The median age was 18 months (range 1-116) and was comparable in white, black and mixed ethnic patients. Primary disease was located in the abdomen (75%), thorax (15%), pelvis (5%) or elsewhere (5%). Evans stage distribution was: stage I, 2%; stage II, 19%; stage III, 21%; stage IV, 50%; and stage IVS, 8%. Stage III/IV disease was more common in black than in white children (p = 0.0001). Urinary vanillyl mandelic acid was elevated in 63% of those tested. Survival after 5-163 months' follow-up was 90% for stages I and II combined (median 2983, range 798-4661 days), 51% for stage III (median 367, range 61-5001 days), 6% for stage IV (median 227, range 20-4379 days) and 50% for stage IVS (median 532, range 54-1543 days). All seven children with para-spinal tumours survived. Individual factors associated with significantly poorer survival were elevated serum lactate dehydrogenase (p < 0.001), Joshi histological risk categorization adapted for age (p = 0.039), n-myc amplification (p = 0.006) and diploidy or tetraploidy (p = 0.006). All seven children with serum ferritin exceeding 149 ng/ml at the time of diagnosis died and survival was 33% in children with 1p deletion and 67% in those without, but the numbers were too small to achieve significance. These findings confirm the benefit of simple biochemical tests and histology in identifying those who are likely to respond favourably to conventional chemotherapy and surgery. Supportive genetic tests on formalin-fixed paraffin-embedded tumour tissue contributed to predicting outcome in 21 patients.

Abdominal Neoplasms↗
PubMed1998

Detection and subtyping of human herpesvirus-8 in renal transplant patients before and after remission of Kaposi's sarcoma.

BACKGROUND: Kaposi's sarcoma (KS) is a complication of renal transplantation. If the human herpesvirus-8 (HHV-8) causes KS, the virus should be present in all KS lesions and be drastically reduced or cleared from involved tissue on remission of the KS. METHODS: Fourteen renal transplant patients with cutaneous KS, including autopsy material from two cases, were investigated for the presence of HHV-8. A second skin biopsy was taken from 11 survivors, after remission of KS, from normal skin in the same anatomical region as the first biopsy. Remission was induced by reduction or cessation of immunosuppression. A peripheral blood sample was collected simultaneously with the repeat biopsy. A nested polymerase chain reaction assay was used to detect HHV-8 DNA in the biopsy tissue and peripheral blood mononuclear cells followed by direct sequencing of polymerase chain reaction product to detect any nucleotide changes. RESULTS: HHV-8 DNA was detected in all the cutaneous KS and all the visceral KS samples, as well as a number of KS-free organs including the thyroid, salivary gland, and myocardium that have not been described before. Mutations in the viral DNA could be demonstrated in all patients. The mutations found were related more to that seen in AIDS-KS cases than that found in African endemic KS cases. HHV-8 sequences could be detected in follow-up frozen skin biopsies of five patients but were negative in the equivalent formalin-fixed specimens. Viral DNA was also detected in 2 of 11 peripheral blood mononuclear cell samples collected at the time of the follow-up skin biopsies. CONCLUSION: Reduction or withdrawal of immunosuppression allows the immune system to recover sufficiently to reduce viral replication with subsequent viral persistence and low grade viral replication that coincides with clinical remission of the KS lesions. This provides further evidence for the important etiological role played by HHV-8 in the pathogenesis of posttransplant KS.

Adult↗
PubMed1998

Characterization of the physical properties of model biomembranes at the nanometer scale with the atomic force microscope.

Interaction forces and topography of mixed phospholipid-glycolipid bilayers were investigated by atomic force microscopy (AFM) in aqueous conditions with probes functionalized with self-assembled monolayers terminating in hydroxy groups. Short-range repulsive forces were measured between the hydroxy-terminated probe and the surface of the two-dimensional (2-D) solid-like domains of distearoyl-phosphatidylethanolamine (DSPE) and digalactosyldiglyceride (DGDG). The form and range of the short-range repulsive force indicated that repulsive hydration/steric forces dominate the interaction at separation distances of 0.3-1.0 nm after which the probe makes mechanical contact with the bilayers. At loads < 5 nN the bilayer was elastically deformed by the probe, while at higher loads plastic deformation of the bilayer was observed. Surprisingly, a short-range repulsive force was not observed at the surface of the 2-D liquid-like dioleoylphosphatidylethanolamine (DOPE) film, despite the identical head groups of DOPE and DSPE. This provides direct evidence for the influence of the structure and mechanical properties of lipid bilayers on their interaction forces, an effect which may be a major importance in the control of biological processes such as cell adhesion and membrane fusion. The step height measured between lipid domains in the AFM topographic images was larger than could be accounted for by the thickness and mechanical properties of the molecules. A direct correlation was observed between the repulsive force range over the lipid domains and the topographic contrast, which provides direct insight into the fundamental mechanisms of AFM imaging in aqueous solutions. This study demonstrates that chemically modified AFM probes can be used in combination with patterned lipid bilayers as a novel and powerful approach to characterize the nanometer scale chemical and physical properties of heterogeneous biosurfaces such as cell membranes.

Diglycerides↗
PubMed1997

TAL-1 protein expression in vascular lesions.

The distribution of TAL-1 protein, an important vascular promoter in mice, has been examined immunohistochemically in a range of human vascular lesions and normal tissues. Formalin-fixed, paraffin-embedded vascular lesions including granulation tissue, haemangiomas, Kaposi's sarcomas, spindle cell haemangioendotheliomas, and angiosarcomas, were examined using a monoclonal antibody to recombinant TAL-1. Endothelial cells in all lesions gave positive immunostaining of variable intensity. Granulation tissue and spindle cell areas of the vascular tumours gave the strongest staining (nuclear and cytoplasmic). The better-differentiated endothelial cells within the tumours and resident well-formed vessels were less positive and some cells were in fact negative. The malignant endothelial cells in angiosarcomas showed less intense positive staining than KS cells. This study has shown TAL-1 protein expression in a range of reactive, benign, and malignant vascular lesions. Protein expression appears to be stronger in the spindle cell areas, perhaps reflecting greater expression in less-differentiated endothelial cells.

Adult↗
PubMed1997

Hepatocellular carcinoma in children.

Hepatocellular carcinoma (HCC) occurs more frequently in subsaharan Africa and the Orient than in other geographical regions, but remains an uncommon tumour of childhood. We review six children with HCC (mean age 13 years) treated by the paediatric oncology unit at Tygerberg Hospital in Cape Town over an 8-year period (1983 - 1990). Patients presented with epigastric and right upper quadrant discomfort and hepatomegaly. The hepatitis B serum antigen (HbsAg) was positive in three patients; serum alpha-fetoprotein (AFP) levels were markedly elevated in three (range 100 - 453,000 microg/l). Age and sex did not differ significantly and all patients initially had irresectable advanced-stage tumours. Morphologically, three were highly malignant adult-type pleomorphic HCCs, two were differentiated tumours, and one a fibrolamellar subtype. The mean 2-year survival was 33% and the 5-year survival 16.6%. The biological behaviour and response to treatment of the tumours varied. Whereas three patients had a poor response to therapy, two with poorly-differentiated tumours, negative HbsAg, and normal serum AFP levels responded to doxorubicin/cisplatinum chemotherapy. This facilitated radical surgical excision. One patient of this group has survived for more than 75 months following surgical resection and remains well. HCC remains an uncommon tumour of childhood with a high mortality. Aggressive chemotherapeutic regimes in combination with surgical resection may lead to improved survival in some cases. Prevention of hepatitis B remains a priority.

Adolescent↗