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J M Pearson

Publications and source records attributed to J M Pearson.

At least 37 records · Page 2Linked to original sources
PubMed1994

Platelets and alpha-naphthylisothiocyanate-induced liver injury.

Administration of alpha-naphthylisothiocyanate (ANIT) to rats results in periportal cholangiolitic hepatopathy. Inflammation is a hallmark of the liver injury, and expression of toxicity is dependent on blood neutrophils. The role of other cellular mediators of inflammation in ANIT-induced hepatic insult is unknown. We hypothesized that platelets participate in the expression of ANIT hepatotoxicity. To test this, circulating platelets were decreased by administration of anti-rat platelet serum (PAb) prior to treatment of rats with ANIT. The PAb treatment regimen effectively reduced circulating thrombocytes over the course of the experiment. Twenty-four hours after oral ANIT administration, rats were euthanized and liver injury was estimated by increases in serum alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) activities. Cholestasis was assessed by measurement of serum total bilirubin concentration and bile flow. Reduction in platelet numbers was associated with attenuation of the increases in plasma ALT activity and bilirubin concentration seen after ANIT administration. However, PAb treatment did not attenuate the increase in plasma GGT, a marker of biliary epithelial cell injury. ANIT-induced changes in platelet function were assessed by evaluating platelet aggregation responses in platelet-rich plasma from rats treated with ANIT in vivo. ANIT treatment modestly decreased ex vivo platelet aggregation in response to ADP and collagen stimuli. To address further the role of platelet-derived cyclooxygenase products in ANIT hepatotoxicity, rats were treated with aspirin or ibuprofen. Neither pretreatment ameliorated ANIT-induced hepatic insult. These results suggest that platelets contribute to the expression of ANIT-induced liver injury, but they do not appear to act through the production of cyclooxygenase metabolites.

1-Naphthylisothiocyanate↗
PubMed1994

An evaluation of five different methods for estimating proliferation in human colorectal adenocarcinomas.

Five different methods of determining cell proliferation have been compared in samples taken from a group of 125 human colorectal tumours labelled in vivo with iododeoxy-uridine (IUdR). The labelling index (LI) was obtained immunocytochemically using monoclonal antibodies against proliferating cell nuclear antigen (PCNA), the Ki67 antigen and IUdR (IUdRimm). Incorporation of IUdR was also determined flow cytometrically (IUdRfcm) and PCNA expression was measured in both formalin- and methanol-fixed tissue (PCNAf and PCNAm respectively). There was significant variation in the results obtained both within and between the different assays. Paired analysis of the data showed that the correlation between the different methods of determining the LI was poor. However, the IUdRfcm LI was significantly correlated with both IUdRimm (r = 0.39; n = 78; P < 0.001 by Spearman's test) and Ki67 LIs (r = 0.32; n = 87; P < 0.001). The IUdRimm LI was also significantly related to the Ki67 LI (r = 0.44; n = 60; P < 0.001). The median IUdRfcm and IUdRimm LIs were significantly higher in the aneuploid vs. the diploid tumours (17.4% vs. 6.2% for IUdRfcm; 23.2% vs. 18.9 for the IUdRimm; P < 0.001 and P = 0.014 respectively by Mann-Whitney U-test) but none of the other proliferative indices showed this relationship. Finally, none of the LIs showed a significant association with the clinical characteristics of the tumours such as stage, grade, age, sex or fixity. The findings of this investigation highlight the need for carefully controlled studies when assessing the value of proliferation markers in solid human tumours.

Adenocarcinoma↗
PubMed1994

Value of electron microscopy in diagnosis of renal disease.

AIMS: To assess the role and value of electron microscopy in the diagnosis of renal disease. METHODS: Retrospective evaluation of 88 renal biopsy specimens received for primary diagnosis by assessment of the contribution of electron microscopy to the final diagnosis in the knowledge of the light microscopy and immunofluorescence findings. RESULTS: Electron microscopy had an important diagnostic role in 75% of cases and was essential or necessary for diagnosis in 25%. In 25% of cases electron microscopy was considered unhelpful in diagnosis. CONCLUSION: Electron microscopy has an integral role in the diagnosis of renal disease, and tissue should be taken for electron microscopy in all cases if possible. In some selected cases once the light microscopy and immunofluorescence findings are known it may be possible to forego electron microscopic examination. Electron microscopy is particularly useful in the differential diagnosis of minimal change disease and the nephrotic syndrome.

Adolescent↗
PubMed1993

Divergent differentiation in small round-cell tumours of the soft tissues with neural features--an analysis of 10 cases.

A series of 10 small round-cell tumours, having in common evidence of neural differentiation, were investigated by immunohistochemistry and electronmicroscopy. In seven, evidence of divergent muscle and/or epithelial differentiation was found. This phenomenon thus appears more common than previously appreciated and suggests that there may be a continuous and overlapping phenotypic spectrum from Ewing's tumour of soft tissue to intra-abdominal desmoplastic small cell tumour.

Adolescent↗
PubMed1992

Endometrium in in-vitro fertilization cycles: morphological and functional differentiation in the implantation phase.

Secretory differentiation of endometrium after multiple follicular stimulation using gonadotrophin releasing hormone and human menopausal gonadotrophin has been studied both histologically and immunohistochemically in 30 women undergoing in-vitro fertilization treatment. None had embryo transfer. Patients were randomly allocated to receive luteal phase support with a single dose of human chorionic gonadotrophin. The latter failed to produce any significant enhancement of endometrial structure or secretions. Appropriate glandular morphology was present in a greater proportion of those who were successfully stimulated than those who responded poorly. However, defective secretion of the cycle-dependent component studied, using monoclonal antibody D9B1, was demonstrated in two-thirds of cases regardless of the ovarian response. Early vascular maturation in the stroma was a common finding, and was thus considered as a feature of structural modulation of these endometria.

Antibodies, Monoclonal↗
PubMed1986

Episodic edema in type 2 lepra reaction can be caused by transient lymphatic obstruction in the lymph node.

Fourteen patients with lepromatous leprosy developed attacks of edema of the hands and/or feet associated with attacks of type 2 lepra reaction (erythema nodosum leprosum). The regional lymph nodes were enlarged and often tender when edema was present. Lymph node biopsies in five cases showed compression of the subcapsular sinus against the thickened fibrotic capsule of the inflamed node. It is suggested that this obstructs the inflow of lymph into the regional nodes, thereby causing the edema.

Adolescent↗
PubMed1986

Convenience food use in households with male food preparers.

Data from the household portion of the 1977-78 USDA Nationwide Food Consumption Survey were used to determine expenditures for convenience and nonconvenience foods and nutrients from those foods. Households with male food preparers accounted for approximately 15% of the survey population, frequently included only one person, and had a larger proportion of young and elderly heads of household than households with a female food preparer. As a group, the foods most frequently reported in households with male food preparers were quite similar to those used by households with female food preparers. Male food preparers spent less of the food dollar on nonconvenience items than did other food preparers, and conversely they spent more on complex and manufactured convenience foods. Total food energy and nutrient levels per nutrition unit of the foods used by households with male food preparers were significantly higher than those in households with female food preparers for all nutrients except thiamin and riboflavin. However, the values were more than 100% of the Recommended Dietary Allowance values except for vitamin B-6 for both sample groups.

Adult↗