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Biomedical subjects

D Kumar

Publications and source records attributed to D Kumar.

At least 199 records · Page 11Linked to original sources
PubMed1994

Pathogenesis of gall stones in Crohn's disease: an alternative explanation.

The increased prevalence of gall stones in Crohn's disease is thought to be related to depletion of the bile salt pool due either to terminal ileal disease or after ileal resection. This study was designed to examine whether this hypothesis is correct and explore alternative explanations. Two hundred and fifty one randomly selected patients (156 females, 95 males, mean age 45 years) were interviewed and screened by ultrasonography to determine the prevalence of gall stones in a large population of patients with Crohn's disease. Sixty nine (28%) patients had gall stones proved by ultrasonography (n = 42), or had had cholecystectomy for gall stone disease (n = 27). The risk factors for the development of gall stones including sex, age, site, and duration of disease, and previous intestinal resection were examined by multivariate analysis. Age and duration of disease were positive risk factors for gall stones and were covariables. The site of disease and of previous intestinal resection did not predispose to gall stones. Previous surgery was an independent risk factor for the development of gall stones, the risk increasing with number of laparotomies. It is suggested that mechanisms other than ileal dysfunction may predispose to gall stones. Postoperative gall bladder hypomotility with biliary sludge formation may be precursors of gall stone formation in patients with Crohn's disease.

Adolescent↗
PubMed1994

Fistulas in ano: endoanal ultrasonographic assessment assists decision making for surgery.

Eighteen patients with a clinical impression of a complex fistula in ano, had anal endosonography to delineate the anatomy of the fistula track and identify associated areas of sepsis. The clinical impression of a complex fistula was refuted by endosonography and subsequent surgical exploration in two cases. Horseshoe tracks were identified in nine (50%) patients and fluid collections, not evident on clinical examination were identified in eight (45%) patients. Accurate identification of the internal opening with a 7 MHz transducer was possible in two (11%) cases. External sphincter damage was evident in four (22%) patients. Surgical findings matched endosonographic appearances in all but one case (94%). Anal endosonography is an accurate and minimally invasive method of delineating the relation of fistula tracks to the anal sphincters and identifying deep areas of sepsis in relation to such fistulas.

Adult↗
PubMed1994

Simplified method for the measurement of segmental colonic transit time.

Segmental colonic transit has been measured in 101 patients. Two MBq of 111Indium absorbed on resin pellets and encapsulated in an enteric coated capsule was given at 7 00 am. Hourly images during the first day, and three images during each subsequent day were acquired for up to three days. Using all scan and patient data the scans were categorised in one of the five patterns of colonic transit: normal, rapid, right delay, left delay, or generalised delay. The geometric centres and per cent activity at each time point was compared between the five groups of colonic transit patients to find the best time for imaging and so to distinguish the five groups. During the first day, early images did not help in diagnosis of patterns of transit, however, in the later images (six hours onwards after the ingestion of the activity) the rapid transit groups could be identified. Images at 27 and 51 hours were both required to distinguish all five groups of patients from each other. Only in the 'normal' transit patients was there some excretion of the activity during the course of the second day, otherwise there was no difference in the images taken in the course of a day (second or third day). A simplified protocol requires a minimum of three images to distinguish all five patterns of colonic transit. The activity should be ingested in the morning (7 00 am) and the first image taken at the end of the working day (8-10 hours after ingestion), the second image on the morning of the second day, and the third image during the course of the third day. This simple protocol would provide all the clinically relevant information necessary for correct classification of the colonic transit.

Adolescent↗
PubMed1994

Lymphoepithelioma-like carcinoma of the breast.

Lymphoepithelioma describes an undifferentiated carcinoma of the nasopharyngeal region characterized by a pronounced reactive lymphocytic infiltrate, often obscuring the neoplastic epithelial component. In recent years, histologically similar lesions have been reported in a number of other sites. We report such a lesion in the breast of a 65-yr-old woman; this site of involvement has not previously been described. The unusual histologic appearance raised other diagnostic possibilities and was a dilemma on frozen section. Immunostains for epithelial markers were particularly useful in delineating the scant epithelial neoplastic elements among the abundant lymphocytic component. In situ hybridization for Epstein Barr viral DNA was negative.

Aged↗
PubMed1994

Comparison of flow cytometric DNA content analysis of fresh and formalin-fixed paraffin-embedded solid neoplasms.

In an attempt to compare results of fresh and fixed tissue flow cytometric DNA analysis we analyzed paraffin blocks of 87 solid tumors; 67 of these were DNA aneuploid and 20 were DNA euploid by fresh flow cytometric analysis. Forty-two aneuploid tumors and all diploid tumors were concordant (71.3% concordance), whereas 25 of 67 (37%) aneuploid tumors appeared diploid on fixed tissue analysis. Reasons for discordance included loss of small aneuploid peaks, merging of G1/G0 peaks of diploid and aneuploid stemlines giving a broad G1/G0 peak, and masking of near-tetraploid aneuploid peaks by the G2/M peak in fixed tissue. S-phase fraction could be determined in 51 of 67 (76%) aneuploid cases analyzed fresh and 29 of 42 (69%) concordant aneuploid cases analyzed from fixed tissues. All parameters were consistently higher in the fixed tissue: S-phase fraction (mean = 18.29% versus 12.82%), coefficient of variation of diploid G1/G0 peak (5.62% versus 2.11%), and DNA index (1.79 versus 1.69). We conclude that significant differences exist between flow cytometric data obtained from analysis of fresh versus fixed tissues and therefore prognostic correlations made on the basis of results of fixed tissue flow cytometric analysis may not necessarily parallel those of fresh tissue studies.

Aneuploidy↗
PubMed1993

Preventive effects of sodium molybdate in lead intoxication in rats.

The role of sodium molybdate (1 mg/kg, intraperitoneally, once daily) supplementation during the course of lead exposure (0.1% lead acetate in drinking water for 4 weeks) in preventing the accumulation of lead in blood and soft tissues and in restoring altered lead-sensitive biochemical variables and the levels of hepatic glutathione, lipid peroxidation, blood Na, blood K, and serum ceruloplasmin was investigated in rats. The data indicate that sodium molybdate significantly protected the uptake of lead in blood, liver, and kidneys and restored the lead-induced inhibited activity of blood delta-aminolevulinic acid dehydratase, elevation of blood zinc protoporphyrin, hepatic lipid peroxidation, and serum ceruloplasmin. The results suggest a significant role of sodium molybdate in preventing plumbism.

Animals↗
PubMed1993

Scintigraphic defecography: quantitative and dynamic assessment of anorectal function.

PURPOSE: Conventional assessment of anorectal function with defecating videoproctography is semiquantitative and the high radiation exposure precludes prolonged or repeated testing. The aim of this study was to develop a dynamic scintigraphic method of assessing anorectal function. METHODS: Fourteen patients with fecal incontinence, 18 patients with chronic constipation, and 8 control subjects were assessed by scintigraphic defecography. This involves introduction of a technetium-99m-radiolabeled artificial stool into the rectum of the subject and acquisition of gamma camera images during evacuation. RESULTS: Mean evacuation rate was 2.8 percent/second in incontinent patients and 0.9 percent/second in constipated patients (P < 0.001). The mean anorectal angles were 136 degrees and 133 degrees, respectively. There were 18 cases of pelvic floor descent and 6 rectoceles. Scintigraphic defecography provides quantitative information on rectal evacuation. Anorectal angle and pelvic floor movement can be examined. The radiation dose to pelvic organs is significantly less than with videoproctography. CONCLUSION: We believe that scintigraphic defecography is the investigation of choice for objective and dynamic assessment of anorectal function.

Adult↗
PubMed1993

C-peptide and the classification of diabetes mellitus patients in the Early Treatment Diabetic Retinopathy Study. Report number 6. The ETDRS Research Group.

The Early Treatment Diabetic Retinopathy Study (ETDRS), conducted at 22 clinical centers during the period 1980 to 1989, collected baseline data on C-peptide levels after ingestion of Sustacal in 582 patients with diabetes mellitus, prior to enrollment in the trial. Data on several clinical factors associated with diabetes were also collected from all 3711 enrolled patients. C-peptide data were used to develop sets of clinical criteria for the classification of ETDRS patients and to compare and contrast definitions of type of diabetes used in previous studies. The distribution of C-peptide levels was strikingly bimodal, suggesting a division of study participants into two groups--those with levels at 80 pmol/L or less and those with more than 80 pmol/L of C-peptide after Sustacal ingestion. Constellations of clinical characteristics that could serve as proxies for C-peptide level were ascertained. The result was two sets of clinically developed definitions for type of diabetes in the ETDRS. According to the more restrictive set of definitions, three groups were identified, compared to two groups using the "broad" set of definitions. Discriminant analysis was also used to classify ETDRS patients, yielding similar results. A comparison of definitions of type of diabetes used in the ETDRS and in previous studies revealed that even in the absence of C-peptide data, clinically derived definitions provided good discrimination between type I and type II diabetes.

Adult↗
PubMed1993

Insulin antibodies: reduction in various anti-insulin IgG subclasses with human insulin therapy.

The insulin-induced antibodies decrease on substitution of bovine-porcine with human insulin. In order to test whether there is a preferential reduction of certain anti-insulin IgG subclass, we investigated the composition of insulin antibodies. In serum samples collected from 23 bovine-porcine insulin-treated patients with clinical manifestations of insulin-induced immune problems (12 insulin resistant cases, 11 with lipodystrophy and/or local insulin allergy), the amounts of 125I-bovine insulin bound with IgG1, IgG2, IgG3 and IgG4 subclasses were 27.0 +/- 4.7, 7.8 +/- 2.3, 39.0 +/- 11.6 and 55.1 +/- 10.9 ng/ml respectively. Thus, there was an abundance of insulin antibodies of IgG4 subclass, and a relative paucity of IgG2. When the bovine-porcine insulin was changed to rDNA human insulin in 15 patients, the total insulin-binding IgG antibodies decreased by 58.6% with concomitant reductions in IgG1 (from 26.7 +/- 6.6 to 16 +/- 5.3), IgG3 (from 5.9 +/- 3.1 to 4.3 +/- 2.1), and IgG4 (from 46.4 +/- 15.6 to 18.4 +/- 7.9 ng of insulin bound/ml) subclasses. These observations suggest that in a selected subset of patients with insulin-induced immune problems, the bovine-porcine insulin induces antibodies of all four IgG subclasses but the IgG4 response predominates. With the substitution to human insulin, a reduction in the immune stimulus occurs followed with decreases in the IgG1, IgG3 and IgG4 subclasses.

Adolescent↗
PubMed1993

Effects of aging, diet, and sex on plasma glucose, fructosamine, and lipid concentrations in barrier-raised Fischer 344 rats.

We studied the relationships of plasma glucose, fructosamine, triglycerides, and cholesterol as a function of age, gender, and diet in barrier-raised Fischer 344 rats aged 5 to 26 months, fed a diet either ad libitum or restricted to 60% of the ad libitum caloric intake. The complex relationships of these plasma levels to age, gender, and diet led to the development of a model with age, diet, and sex as covariates. Overall, fasting plasma glucose concentrations were reduced by approximately 25% in rats on the restricted diet, compared to ad libitum-fed animals. There was a significant age-dependent decline in glucose levels in male animals, whereas in females there was an increase in plasma glucose with aging. Plasma fructosamine levels in calorie-restricted animals, overall, were reduced by 7% compared to levels in animals fed ad libitum. There was a significant positive correlation between plasma glucose and fructosamine levels. Mean plasma triglyceride content was decreased by 50% in calorie-restricted rats compared to ad libitum-fed animals. A significant decrease in triglyceride levels with increasing age was seen in male animals, and an increase with aging in females. There was a significant positive correlation between plasma glucose and triglyceride levels. Plasma cholesterol levels in calorie-restricted animals were reduced by 7% compared to levels in ad libitum-fed animals. An increase of cholesterol concentration with aging was significant in both males and females. Analysis of the data showed that there were significant differences between male and female Fischer 344 rats in the response of plasma glucose and fructosamine to aging and calorie restriction. Changes of plasma triglyceride and cholesterol with aging and dietary calorie restriction were also different in males and females. Studies of the effect of aging on glycemia and blood lipid content should take into account the contributions of animal sex.

Aging↗
PubMed1993

Recurring phyllodes tumor in aberrant breast tissue of the vulva.

A 20-year-old nulligravida woman presented with bilateral cystic nodules of the vulva, diagnosed after simple excision as benign phyllodes tumor. Breast tissue, which also displayed fibrocystic changes, was also recognized. Follow-up at 2 months revealed no evidence of disease; however, 8 months after surgery she returned with a new mass in the vulva. This was excised and found to be recurrent phyllodes tumor. Although somewhat more cellular than the first lesions, it also was deemed to be benign based on histological features supported by flow cytometric DNA studies.

Adult↗
PubMed1993

Epstein-Barr virus-associated T-cell lymphoma in a renal transplant patient.

Posttransplant lymphoproliferative disorders in organ allograft recipients are most commonly of B cell origin, whereas T cell lymphomas are rarely described. We report a case of T cell immunoblastic large cell lymphoma associated with Epstein-Barr virus (EBV) that occurred in a recipient of a cadaveric renal transplant 7 years posttransplantation. On paraffin immunophenotyping, none of the neoplastic cells stained with the T cell-associated markers used, but did show strong CD30 expression. Flow cytometric studies revealed a predominance of T cells without definite evidence of T cell neoplasia. Frozen section immunophenotyping studies revealed a T cell phenotype with aberrant expression, and genotypic studies demonstrated T cell receptor beta gene rearrangement with germline configuration of immunoglobulin heavy chain and kappa light chain genes, confirming a T lineage. EBV-encoded RNA transcripts were demonstrated within the neoplastic cells by in situ hybridization. Southern blot analysis using probes derived from the terminal repeat region of the virus detected a single restriction band indicating a clonal population. We believe this is the first case of a posttransplant T cell lymphoma in which the EBV genome has been demonstrated. This case also illustrates the pitfalls of paraffin immunophenotyping in the diagnosis of T cell lymphoma.

Adult↗
PubMed1993

Anal sphincter defects. Correlation between endoanal ultrasound and surgery.

OBJECTIVE: This study was performed to (1) correlate and sphincter defects, identified by endoanal ultrasound with operative findings, and (2) define the appearance of such sphincter defects as seen at operation. SUMMARY BACKGROUND DATA: Endoanal ultrasonography is a minimally invasive method of imaging the anal sphincter complex and enables identification of anal sphincter defects. Little is known about the accuracy and limitations of endoanal ultrasound in identifying such defects. Furthermore, there are no data about the appearances of these endosonic sphincter defects as seen at operation. METHODS: Forty-four patients (40 women; age range, 26 to 80 years; mean age, 56 years) with fecal incontinence, undergoing pelvic floor repair, were investigated by endoanal ultrasound before operation. Endosonic findings were correlated with the appearances of external anal sphincter, internal anal sphincter, and intersphincteric space, at operation. Diagnosis of the site and type of defect was made by macroscopic appearances. Uncertainty about the type of sphincter defect was resolved by obtaining muscle biopsies for histology. RESULTS: All external sphincter defects seen by endoanal ultrasound (n = 23) were confirmed at operation. Twenty-one of 22 internal sphincter defects identified by endosonography also were confirmed at operation. In ten patients with a neuropathic anal sphincter complex, the morphology was normal on endosonography, and this was confirmed at operation. (Sensitivity and specificity of 100% for external anal sphincter; 100% and 95.5%, respectively, for internal and sphincter) CONCLUSIONS: These data show that endoanal ultrasound is an accurate method of identifying anal sphincter defects.

Adult↗
PubMed1993

Measurement of colonic transit time using radionuclide imaging: analysis by condensed images.

A polymer-coated capsule has been used in eight volunteer subjects to deliver 111In-resin into the ileocaecal region. The images were acquired for up to 3 days to follow transit through the colon. Expressing the results of individual studies is difficult and time-activity curves for each region are confusing. Calculation of the geometric centre indicates only where the middle of the activity has reached. We describe a new method of presenting colonic transit data as parametric images. The parametric images show the amount of activity in each area of interest as the study progresses. This is readily understood and allows segmental movement of the isotope, either forward or retrograde, to be examined. The geometric mean of activity in four areas of the colon were also calculated. Four hours after reaching the ileocaecal region, 65% (S.D. 24%) of the activity was in the caecum and 26% (S.D. 20%) in the transverse colon. By 24 h three controls had excreted most of the activity, in two the activity was mainly in the rectum and in two there was still some activity in the transverse colon. A protocol for colonic transit studies, problems with analysis and a new method of presentation of data are discussed.

Acrylic Resins↗