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Biomedical subjects

A Patel

Publications and source records attributed to A Patel.

At least 325 records · Page 18Linked to original sources
PubMed1995

Differential calcitonin gene-related peptide (CGRP) and amylin binding sites in nucleus accumbens and lung: potential models for studying CGRP/amylin receptor subtypes.

Calcitonin gene-related peptide (CGRP), a 37-amino-acid peptide, is a member of a small family of peptides including amylin or islet amyloid polypeptide and salmon calcitonin. These related peptides have been shown to display similar effects on in vitro and in vivo carbohydrate metabolism. The present study was initiated to identify and characterize the binding sites for these peptides in lung and nucleus accumbens membranes prepared from pig and guinea pig. Both tissues in either species displayed high-affinity (2-[125I]iodohistidyl10)humanCGRP alpha ([125I]hCGRP alpha) binding (IC50 = 0.4-7.7 nM), which was displaced by hCGRP8-37 alpha with equally high affinity (IC50 = 0.4-7.3 nM). High-affinity binding for [125I]Bolton-Hunter human amylin ([125I]BH-h-amylin) was also observed in these tissues (IC50 = 0.2-6.0 nM). In membranes from the nucleus accumbens of both species, salmon calcitonin competed for amylin binding sites with high affinity (IC50 = 0.1 nM) but was poor in competing for amylin binding in lung membranes. Rat amylin8-37 competed for [125I]hCGRP alpha binding with higher affinity (IC50 = 5.4 nM) compared with [125I]BH-h-amylin binding (IC50 = 200 nM) in porcine nucleus accumbens, whereas in guinea pig nucleus accumbens, the IC50 values for rat amylin8-37 were 117 and 12 nM against [125I]hCGRP alpha and [125I]BH-h-amylin, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1995

Disseminated Penicillium marneffei: presenting illness of advanced HIV infection; a clinicopathological review, illustrated by a case report.

BACKGROUND: Until recently Penicillium marneffei rarely caused human disease. It is now a frequently encountered opportunistic mycosis in HIV positive residents of, and travellers to, south-east Asia. AIMS: To review aspects of clinical presentation, pathology, treatment, epidemiology and ecology of P. marneffei. To report a case of disseminated P. marneffei occurring in the Northern Territory which illustrates many typical clinical and pathological features of this infection. CASE PRESENTATION: A Burmese immigrant presented to Royal Darwin Hospital, Australia with a non-specific, subacute, febrile illness and a diffuse papular rash. The etiological agent was Penicillium marneffei, disseminated in association with advanced HIV infection. The typical travel history and umbilicated papular rash were recognized on admission. Fungal stains of skin biopsies and touch smears facilitated rapid diagnosis, and early antifungal therapy resulted in clinical cure. CONCLUSIONS: Early distinction of penicilliosis from other opportunistic mycoses, tuberculosis, Leishmaniasis, and molluscum contagiosum is critical for effective management. The characteristic histological and mycological properties of P. marneffei are easily recognizable if the diagnosis is considered. In view of geographic proximity, travel and immigration from endemic areas, Australia should expect further imported penicilliosis as illustrated by this case report.

AIDS-Related Opportunistic Infections↗
PubMed1995

The prevalence of polycystic ovaries in the hepatic glycogen storage diseases: its association with hyperinsulinism.

OBJECTIVE: There has been much debate concerning the relative contribution of insulin resistance to the development of polycystic ovaries (PCO). We therefore aimed to assess ovarian morphology and insulin/androgen status in females with the hepatic glycogen storage diseases types Ia (GSD-Ia) and III (GSD-III), disorders associated with abnormalities of insulin secretion. DESIGN: A cross-sectional study of ovarian ultrasonography, oral glucose tolerance tests (oGTTs) and single measurements of gonadotrophins and androgens were performed. PATIENTS: Twenty-seven patients were evaluated: 13 with GSD-Ia, median age 11.2 years (range, 3.3-26.7) and 14 with GSD-III, aged 13.2 years (4.2-31.3). None had clinical signs of hyperandrogenism and only two of the 13 adults (15%) had menstrual irregularities. They were compared to 9 normal adult female controls, aged 21-28 years. MEASUREMENTS: Ovarian morphology and volume were measured. Blood glucose and plasma insulin concentrations were measured at the beginning and end of a 2-hour oGTT. Single measures of LH, FSH, testosterone, dehydroepiandrosterone sulphate, androstenedione, IGF-I and SHBG were made on samples taken at the beginning of the oGTT. RESULTS: In both GSD-Ia and III, all those older than 4.8 years of age had a polycystic ovarian appearance. Pre-pubertal GSD-Ia patients had lower basal and 2-hour blood glucose and plasma insulin concentrations than pre-pubertal GSD-III patients. In adults with GSD-Ia and GSD-III, although basal and 2-hour blood glucose concentrations did not differ, both basal and 2-hour plasma insulin concentrations were significantly higher than controls. Serum gonadotrophins, androgens, IGF-I and SHBG were mostly normal. CONCLUSIONS: A polycystic ovarian appearance is a common finding in patients with glycogen storage disease even before puberty. In GSD-III and adults with GSD-Ia, this ovarian appearance was associated with hyperinsulinism, suggesting an aetiological link, but this was not the case in pre-pubertal children with GDS-Ia. Inborn errors of carbohydrate metabolism may act as useful models for examining control mechanisms of ovarian physiology and development.

Adolescent↗
PubMed1995

Cytokeratin 20 expression by non-invasive transitional cell carcinomas: potential for distinguishing recurrent from non-recurrent disease.

Although approximately 50% of patients with non-invasive (Ta) papillary transitional cell carcinoma show no recurrence of their disease, current histopathological approaches cannot distinguish this sub-group from those patients in whom the disease will recur. In this 5 year retrospective study, we have shown that cytokeratin 20 (CK20) was expressed in 19 of 29 (65.5%) of non-invasive papillary tumours of grades 1 or 2. CK20 expression patterns were predictive of disease non-recurrence in a sub-group of eight patients, representing 51.7% of patients with non-recurrent disease. In normal bladder mucosa, CK20 expression was restricted to the terminally-differentiated superficial cell. In eight CK20-positive tumours which showed no recurrence at 5 years, CK20 expression was either restricted to, or most intense in, the luminal cells of the papillae. This pattern of expression was not seen in any of the 15 tumours from the recurrent group. Disruption of normal CK20 expression was highly significantly correlated with recurrent tumours. These results suggest that changes in the expression of differentiation-associated antigens, such as CK20, may be useful in predicting benign versus malignant behaviour and may, therefore, be useful in defining treatment strategies.

Adult↗
PubMed1995

Classification of psychotic symptoms in dementia sufferers.

Little attention has been payed to the classification of psychotic symptoms in dementia sufferers. This article compares the etiology of delusions, visual hallucinations and delusional misidentification and examines the value of factors generated from principal components analysis as a possible classificatory system in a group of 125 patients with DSM-III-R dementia in contact with clinical services who were prospectively evaluated using standardized instruments to describe in detail individual psychotic symptoms. The assessment also included the Geriatric Mental State Schedule, the History and Aetiology Schedule and the CAMCOG. Delusions and visual hallucinations had a distinct cognitive profile as did delusions and delusional misidentification, although there was an overlap between visual hallucinations and delusional misidentification. Four factors were generated from principal components analysis. Three of these closely mirrored the 3 symptom groups delusions, visual hallucinations and delusional misidentification, although the phantom-boarder delusion was correlated with the visual hallucination factor and not delusional misidentification. The fourth factor included visual hallucinations of relatives and delusions that relatives were in the house. This factor was strongly inversely associated with emotional distress and could perhaps best be seen as a comfort phenomena. The pattern of cognitive deficits and etiological associations of each of the factors were independent of one another, supporting the notion that it is useful to consider them as separate entities.

Aged↗
PubMed1995

Recombinant mink cell focus-inducing virus and long terminal repeat alterations accompany the increased leukemogenicity of the Mo+PyF101 variant of Moloney murine leukemia virus after intraperitoneal inoculation.

We recently showed that different routes of inoculation affect the leukemogenicity of the Mo+PyF101 variant of Moloney murine leukemia virus (M-MuLV). Intraperitoneal (i.p.) inoculation of neonatal mice with Mo+PyF101 M-MuLV greatly enhanced its leukemogenicity compared with subcutaneous (s.c.) inoculation. We previously also suggested that the leukemogenicity defect of Mo+PyF101 M-MuLV when inoculated s.c. may result from the inability of this virus to form env gene recombinant (mink cell focus-inducing [MCF]) virus. In this study, virus present in end-stage tumors and in preleukemic animals inoculated i.p. by Mo+PyF101 M-MuLV was characterized. In contrast to s.c. inoculation, all tumors from i.p.-inoculated mice contained high levels of recombinant MCF virus. Furthermore, Southern blot analyses demonstrated that the majority of the tumors contained altered Mo+PyF101 M-MuLV long terminal repeats. The U3 regions from several tumors with altered long terminal repeats were cloned by PCR amplification. Sequence analyses indicated that the M-MuLV 75-bp tandem repeat in the enhancer region was triplicated. This amplification was also previously observed in mice infected s.c. with a pseudotypic mixture of Mo+PyF101 M-MuLV and Mo+PyF101 MCF virus. The enhancer triplication was an early event, and it occurred within 2 weeks postinfection. Recombinant MCF viruses were not detected by Southern blot analyses until 4 weeks postinfection. Thus, the M-MuLV enhancer triplication event was initially important for efficient propagation of ecotropic Mo+PyF101 M-MuLV. The increased leukemogenicity following i.p. inoculation could be explained if the triplication enhances Mo+PyF101 M-MuLV replication in the bone marrow and bone marrow infection is required for recombinant MCF virus formation.

3T3 Cells↗
PubMed1995

Multifocal renal cell carcinoma in sibs from a chromosome 9 linked (TSC1) tuberous sclerosis family.

Multifocal renal cell carcinomas (RCCs), together with angiomyolipomas (AMLs) and renal cysts, were identified in early adult life in two sisters with tuberous sclerosis (TSC). They were members of a multigenerational tuberous sclerosis family showing strong evidence for a mutant TSC causing gene on chromosome 9 (TSC1). Previous reports of multifocal RCC in young patients with TSC suggest that constitutional mutations at the TSC loci may predispose to RCC. In the rat a germline mutation affecting the TSC2 gene is associated with transmission of multifocal RCC as an autosomal dominant trait. However, the cases reported here are the first to suggest a similar role for the TSC1 gene in renal cell carcinogenesis.

Adenocarcinoma, Clear Cell↗
PubMed1995

Effect of time of day of dialysis shift on serum biochemical parameters in patients on chronic hemodialysis.

It is unknown whether predialysis serum biochemical parameters may differ among chronic hemodialysis patients depending on the shift during which they are dialyzed. We studied 115 patients on chronic hemodialysis in our institution for 3 consecutive months and compared clinical and biochemical parameters based on the shift during which they were dialyzed. Predialysis serum potassium was found to be progressively higher for patients dialyzed on later as compared with earlier dialysis shifts, and phosphate was significantly higher for patients dialyzed during the evening shift as well. Regression analysis suggested that higher of potassium and phosphate levels were related to the time of day these sessions and not to patient age, amount of dialysis given or diet. By contrast, serum albumin, creatinine, sodium, and chloride levels were found to differ depending on dialysis shift, though these differences appeared to be accounted for by patient age. We concluded that the time of day of the beginning of the dialysis shift appears to mildly influence the levels of serum predialysis biochemical parameters which are important in monitoring patients on chronic hemodialysis, in particular potassium and phosphate. Further insight into the mechanism of this observed effect might improve our ability to interpret and treat derangements of these serum biochemical parameters in patients on chronic hemodialysis.

Case-Control Studies↗
PubMed1995

Significance of fracture gap in open tibial fracture.

The healing pattern of medial and lateral cortical gap in open transverse or short oblique tibial fractures were retrospectively reviewed in 2 groups; In group A, 16 patients were treated by Judet external fixator in rigid mode. In group B, 6 patients were treated in biocompressive mode, which allowed predominantly longitudinal axial motion. The characteristic healing pattern in group A was gap healing without or with minimal periosteal callus. The healing time and time for consolidation per 1mm gap were significantly longer in medial cortices than lateral ones (p < 0.036, p < 0.024 respectively). In group B, the fractures were healed with periosteal callus. There was no difference in the healing time and the time for consolidation per 1mm gap between the two cortices. The consolidation time per 1mm gap in the medial cortices was significantly longer in group A than group B (p < 0.020). The longitudinal axial motion in open transverse tibial fractures seems to shorten the healing time effectively in the medial cortex.

Adolescent↗
PubMed1995

HCFA's Medicare mortality statistics for a New Jersey hospital.

We assessed the severity of illness in 40 Medicare patients with an acute myocardial infarction to determine whether HCFA's observed-to-predicted mortality ratio was related to quality of care or severity of illness. The authors present a study from a New Jersey hospital.

Acute Disease↗
PubMed1995

Collagen and collagenase mRNAs in normal and sclerotic glomeruli: predictors of progression and response to therapy.

Progressive glomerulosclerosis is associated with decreasing kidney function, eventuating in end-stage renal failure. There are multiple components of the extracellular matrix, and the exact composition in various renal diseases is not known. Thus, we examined some of the major components of the extracellular matrix (ECM) in murine and human glomerular diseases. We studied matrix synthesis and degradation at the level of gene expression and ECM composition in the intact glomerulus. To determine whether the composition of sclerosis was similar among diseases, we examined a normal mouse strain and compared it with strains which spontaneously developed glomerulosclerosis. The baseline levels of matrix components varied between different mouse strains, and this level correlated with their propensity to develop glomerulosclerosis. In addition, when glomerulosclerosis was induced, the baseline ECM mRNA level predicted the subsequent outcome. We studied mice transgenic for bovine growth hormone, since they develop progressive glomerulosclerosis. Treatment with heparin substantially decreased the lesions without changes in type IV collagen mRNAs. However, there was an up-regulation of both the mRNA and enzyme activity for the 92 kD matrix metalloproteinase. In contrast, when these mice were treated with either angiotensin converting enzyme inhibitors or angiotensin II (Ang II) receptor antagonists, the glomerulosclerosis was accentuated histologically and the ECM synthetic and degradative mRNAs were elevated. These data suggest that the mRNA levels reflect response to therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Innovations in non-isotopic DNA sequencing: using an electrotransfer unit to blot sequencing gels and an automated membrane processor for detecting DNA sequences.

As alternatives to radiolabeled DNA sequencing, chemiluminescent and chromogenic sequencing methods can be comparable in both sensitivity and resolution. Chemiluminescent/chromogenic detection procedures are safer because they completely eliminate the handling and use of radioisotopes. One method involves standard dideoxy DNA sequencing reactions that are initiated with biotinylated primers, separated by gel electrophoresis, transferred onto nylon membrane and detected utilizing chemiluminescent 1,2-dioxetane substrates for alkaline-phosphatase. Alkaline phosphatase is linked to the biotinylated sequencing products by a streptavidin/alkaline phosphatase conjugate (SAAP). In this paper we describe an optimized procedure for transferring sequencing gels. The procedure is based on a semidry method developed at Hoefer Laboratories using the GeneSweep Sequencing Gel Transfer Unit. Transfer is rapid, uniform and reliable from gel to gel. We also describe automation of the development process using a fully programmable Gel/Membrane Processor that automates delivery, incubation and disposal of reagents. All crucial points for electrotransfer of sequencing gels and the detection of biotinylated DNA sequencing reaction products are discussed.

Alkaline Phosphatase↗
PubMed1995

Myometrial hyperplasia: proposed criteria for a discrete morphological entity.

Myometrial hyperplasia is not a well-established morphological entity. Technical obstacles regarding uterine weight, myometrial cellularity, and myometrial cell orientation have made it difficult to establish objective criteria for diagnosis. In this study, 15 slides that had been interpreted as within normal limits on routine examination were reevaluated because there were areas of myometrium that stood out as relatively blue on scanning magnification of H&E-stained sections. Morphometrically, they all had increased myometrial cellularity, compared with normal myometrium elsewhere on the same slide (P < 0.05), and an increased nucleus/cell ratio (P < 0.001). They occurred in three patterns. The diffuse inframucosal form and the subserosal plaque-like form sometimes corresponded to grossly detectable inframucosal bulges or subserosal ridges. There was also an occult, microscopic intramural pattern of myometrial hyperplasia, which differed from seedling leiomyomas by its lack of nodularity and compression of adjacent myometrium. We propose that these criteria may permit an objective diagnosis of myometrial hyperplasia. We believe that it will be of interest to explore the clinical significance, cell biology, and pathogenesis of this distinctive variation in myometrial structure.

Adult↗