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Biomedical subjects

D Kumar

Publications and source records attributed to D Kumar.

At least 145 records · Page 8Linked to original sources
PubMed1998

Apocrine metaplasia: mammographic and sonographic appearances.

OBJECTIVE: Our objective was to evaluate the mammographic and sonographic appearances of apocrine metaplasia and correlate imaging and histopathologic findings. MATERIALS AND METHODS: Retrospective review of 408 lesions in 318 consecutive patients undergoing core needle biopsy (n = 370) or fine needle aspiration (n = 38) revealed 46 cases of apocrine metaplasia. In 17 of these cases, apocrine metaplasia represented more than 50% of the lesion sampled; these 17 lesions formed the basis for analysis. RESULTS: On mammography, all 17 cases appeared as new or enlarging equal-density (n = 15) or low-density (n = 2) masses with an average size of 12.8 mm. Borders were microlobulated in 59% (10/17), macrolobulated in 29% (5/17), and circumscribed or oval in 12% (2/17). Sonography revealed a lobulated mass containing a cluster of small (2- to 5-mm) anechoic foci and intervening septae in 77% (10/13) of cases. A discrete hypoechoic solid component was seen in 23% of cases (3/13). Posterior acoustic enhancement was seen in 85% of cases (11/13). In 65% of lesions (11/17), we noted a decrease in size or total resolution during biopsy or fine needle aspiration. Histopathologic examination showed the typical appearance of dilated cystic acini lined by apocrine metaplastic epithelium. CONCLUSION: On mammography, the combined findings of an equal- or low-density microlobulated or lobulated mass that corresponds on sonography to a cluster of small (2- to 5-mm) anechoic foci with intervening septae should suggest the diagnosis of focal apocrine metaplasia. With radiologists' increasing experience, follow-up, rather than biopsy, of such typical-appearing lesions may be adequate.

Adult↗
PubMed1998

Predictive value of specimen radiography for core needle biopsy of noncalcified breast masses.

OBJECTIVE: Our objective was to determine the predictive value of specimen radiography for large core (14-gauge) needle biopsy of noncalcified breast masses. SUBJECTS AND METHODS: Eighty-four biopsies of 83 breast masses yielded 403 specimens. Specimens showing dense material on specimen radiography were predicted to be diagnostic; specimens showing intermediate- or low-density material were predicted to be nondiagnostic. Specimen radiographic and histopathologic findings were correlated for each specimen using vital dyes to mark individual specimens. RESULTS: Of the 403 specimens, 307 (76%) contained diagnostic material representative of the lesion, with a specific diagnosis achieved for 82 (99%) of 83 lesions (62 benign, 20 malignant). Of the 293 passes containing dense material, 268 (91%) proved to be diagnostic; 11 (18%) of 62 specimens containing only low-density material proved to be diagnostic. Of the 25 (9%) of 293 specimens containing radiographically dense but nondiagnostic material, 18 (72%) showed focal fibrosis and had missed the lesion; 15 (83%) of 18 such specimens were obtained in dense parenchyma. The positive predictive value of specimen radiography was 13 (100%) of 13 in fatty breasts; 77 (96%) of 80 in breasts with minimal scattered fibroglandular elements; 91 (94%) of 97 in heterogeneously dense breasts; and 35 (70%) of 50 in breasts with extremely dense parenchyma. Of the 16 lesions sampled stereotactically, specimen radiography helped assess the inadequacy of initial sampling in three (19%). In six (9%) of 68 sonographically guided biopsies, only one or two specimens could be obtained; specimen radiography helped us predict whether material was adequate for diagnosis. CONCLUSION: Radiography of core specimens obtained from noncalcified breast masses accurately reveals the adequacy of sampling unless the breast parenchyma is extremely dense. Such immediate assessment can help ensure adequate material from lesions that are difficult to biopsy and can thereby improve the diagnostic yield of large core needle breast biopsy.

Adolescent↗
PubMed1998

Diabetic peripheral neuropathy. Effectiveness of electrotherapy and amitriptyline for symptomatic relief.

OBJECTIVE: To evaluate the efficacy of combining electrotherapy with amitriptyline for the management of chronic painful peripheral neuropathy in patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Patients (n = 26) with peripheral neuropathy were treated with amitriptyline. After 4 weeks, those patients (n = 23) who failed to respond to amitriptyline or who only had partial relief were randomized between a sham treatment group (control) or an electrotherapy group. Transcutaneous electrotherapy was given for 12 weeks by a portable unit (H-wave machine) that generated a biphasic exponentially decaying waveform (pulse width 4 ms, 25-35 V, > or = 2 Hz). The degree of pain and discomfort was graded on a scale of 0-5. An analog scale was used to record the overall change in symptoms. RESULTS: Amitriptyline produced some degree of symptomatic relief in 15 (60%) of the 26 patients by the 4th week; pain scores decreased from 3.8 +/- 0.1 to 2.9 +/- 0.2 (P < 0.1) and the overall reduction in pain was 26 +/- 5% on an analog scale. In the amitriptyline plus sham treatment group (n = 9), pain scores declined from 2.8 +/- 0.3 to 1.9 +/- 0.5 (P < 0.03) and the overall reduction in pain was 55 +/- 12%, suggesting a procedure-related placebo effect. In the group receiving combined electrotherapy and amitriptyline (n = 14), symptomatic improvement occurred in 12 (85%) patients. Five (36%) of the patients in this group became asymptomatic. Pain scores declined from 3.2 +/- 0.2 to 1.4 +/- 0.4 (P < 0.01) and the overall reduction in pain was 66 +/- 10%. The degree of reduction in pain scores and the incremental relief (above the amitriptyline effect) were significantly greater (P < 0.03) with electrotherapy as compared with sham treatment. The outcomes indicate a substantial beneficial effect of electrotherapy over and above any placebo influence. CONCLUSIONS: Our clinical observations suggest that transcutaneous electrotherapy is effective in reducing the pain associated with peripheral neuropathy. This form of therapy may be a useful adjunctive modality when it is combined with a pharmacological agent, such as amitriptyline, to augment symptomatic relief.

Adult↗
PubMed1998

Primary hepatic low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) associated with primary biliary cirrhosis.

We describe a case of low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) arising in the liver of a patient with early-stage primary biliary cirrhosis (PBC). The patient, a 62-year old woman, presented with abnormal liver function tests, a positive antimitochondrial antibody titer (1:160), and a liver mass. The resected mass, 6.0 x 5.0 x 4.0 cm, had the features of MALT-type lymphoma. The neoplastic cells were small lymphoid cells of B-cell lineage that surrounded reactive lymphoid follicles and infiltrated bile ductules to form lymphoepithelial lesions. The uninvolved liver had histologic evidence of early stage PBC, characterized by segmental duct destruction with granulomata and an inflammatory infiltrate in the portal triads composed of lymphocytes, plasma cells, and occasional eosinophils. A periportal lymph node showed histologic features of the hyaline-vascular type of Castleman's disease, without evidence of malignant lymphoma. Low-grade B-cell lymphomas of the MALT type rarely arise in the liver and, to our knowledge, have not been reported previously in association with PBC. The association in this case suggests that chronic antigenic stimulation as a result of PBC induced the accumulation of acquired MALT, which subsequently transformed to low-grade B-cell lymphoma.

Female↗
PubMed1998

An easy method for detection of rheumatic antigen(s) in rheumatic fever/rheumatic heart disease patients by dot-ELISA.

BACKGROUND: Various monoclonal antibodies developed against human B cell alloantigen have different positivity in different population groups around the world. Thus, monoclonal antibody D8/17, found to be 100% specific for rheumatic fever/rheumatic heart disease (RF/RHD) patients from New York, identified only 62% to 68% in the north Indian population. PATIENTS AND METHODS: A battery of monoclonal antibodies against B cell alloantigen was developed in Indian RF/RHD patients. A total of 50 patients and 25 controls were studied. RESULTS: These antibodies, named PG-12A, -13A and -20A, demonstrate more specificity in north Indian patients. In dot-ELISA, these antibodies correctly show the presence of the marker in 84% of RHD and 90% of recurrence of rheumatic activity patients. CONCLUSIONS: It is suggested that different alloantigens are expressed in the north Indian population. This standardized dot-ELISA is low cost and simple to use, and has a very high percentage of sensitivity, specificity and positive predictive value for this population.

Antibodies, Monoclonal↗
PubMed1998

Mammographic-histopathologic correlation of large-core needle biopsies of the breast.

Large-core (14g) needle biopsy (CNB) of the breast is a new diagnostic modality increasingly being used to evaluate patients with mammographic abnormalities. Two hundred twenty-four CNBs were performed on 198 patients. Surgical follow-up was available in 64 cases (28.6%). Overall concordance rate was 93.8% (60 of 64 cases). Of the four discordant cases, two were diagnosed as atypical ductal hyperplasia (ADH) on CNB; on excision, these cases showed cribriform ductal carcinoma in situ (DCIS); two remaining cases, diagnosed on CNB as ADH versus DCIS, showed invasive carcinoma (DCIS with invasive component and infiltrating cribriform carcinoma, respectively) on excisional biopsy. Malignancy, primary (52) or metastatic (5), was identified in 57 cases (25.4%); 47 of these patients underwent surgical excision, and the diagnosis was confirmed in all of these cases. Of 51 cases with radiographic evidence of microcalcifications, 48 (94%) had microcalcifications in the CNB: 30 (62.5%) were benign, 11 (22.9%) were malignant, and 7 (14.6%) were diagnosed as ADH. In the remaining three cases (1.3%), only benign breast tissue without microcalcifications was seen, and the lesion was considered to have been missed. Biopsy specimens were obtained from 173 lesions because of the presence of a mass: 125 (72.3%) were benign, 45 (26%) were malignant, and 3 (1.7%) were diagnosed as ADH. Follow-up was available in 118 patients with benign lesions: all were mammographically stable or decreased at 6 or 12 months; no follow-up was available for the remaining patients. CNB of the breast is a highly sensitive (96.9%) and specific (100%) technique for management of patients with mammographic abnormalities. The histologic findings should be correlated with the mammographic appearance, and an attempt should be made to achieve a specific diagnosis in all lesions, particularly masses. The diagnosis of ADH should always prompt excisional biopsy because of a high frequency of false-negative results caused by sampling errors or underestimation.

Adolescent↗
PubMed1997

Recombinant Mycobacterium aurum expressing Escherichia coli beta-galactosidase in high throughput screening of antituberculosis drugs.

Mycobacterium aurum is considered a surrogate of M. tuberculosis and recently has been proposed as test organism in high throughput screening of antituberculosis drugs (3). In this investigation, we suggest use of a recombinant M. aurum expressing E. coli lacZ gene, in which beta-galactosidase production is the reporter system as recently reported by us (6). The assay is based on production of beta-galactosidase in presence of drugs during growth. Enzyme production was inhibited within 4 h by frontline antimycobacterial drugs like streptomycin, rifampicin, isoniazid, ethambutol, ofloxacin, and sparfloxacin at their MICs. The assay could be performed conveniently in 96-well microtiter plate format.

Antitubercular Agents↗
PubMed1997

beta-Galactosidase reporter system in mycobacteria and its application in rapid antimycobacterial drug screening.

Pathogenic mycobacteria are generally slow growing organisms and it takes several weeks to evaluate inhibitors of growth. Therefore, for rapid screening of the inhibitors of mycobacterial growth, a beta-galactosidase reporter system has been described which utilises a recombinant Mycobacterium smegmatis mc(2)155 expressing E. coli lacZ gene as the test organism. The assay is based on production of beta-galactosidase in presence of drugs during growth. A correlation between beta-galactosidase production and colony forming ability of mycobacteria was obtained. beta-galactosidase production was inhibited within 6 h by front line standard antimycobacterial drugs like streptomycin, rifampicin, isoniazid, ethambutol, pyrazinamide and ofloxacin at their reported MICs. The assay was performed on mycobacterial cells permeabilized with chloroform and sodium dodecyl sulfate.

Anti-Bacterial Agents↗
PubMed1997

Familial aplasia/hypoplasia of pelvis, femur, fibula, and ulna with abnormal digits in an inbred Pakistani Muslim family: a possible new autosomal recessive disorder with overlapping manifestations of the syndromes of Fuhrmann, Al-Awadi, and Raas-Rothschild.

We describe four affected children belonging to a large, highly inbred Muslim family originating from the North West Frontier Province of Pakistan. All children have a similar pattern of skeletal abnormalities, including aplasia/hypoplasia of the ulnae, hypoplasia of the pelvis, aplasia/hypoplasia of the femora, fibular aplasia, and variable digital abnormalities and absent/dysplastic nails. The phenotype overlaps with the syndromes of Fuhrmann, Al-Awadi, and Raas-Rothschild. The present and previously reported families probably share the same geographic and racial origin, indicating a common genetic basis of the reported skeletal abnormalities in these limb-pelvis aplasia and hypoplasia syndromes. A possibility of a new autosomal recessive syndrome in the present family cannot be excluded. Further delineation and molecular studies are required to clarify the genetic cause and phenotypic variation in Fuhrmann, Al-Awadi, and Raas-Rothschild syndromes.

Abnormalities, Multiple↗
PubMed1997

Parenteral gene therapy with p53 inhibits human breast tumors in vivo through a bystander mechanism without evidence of toxicity.

Mutations of the p53 tumor suppressor gene are the most frequently observed genetic lesion in human cancer. Previously, we found that multiple intravenous injections of a liposome:p53 complex inhibited the growth of a malignant human breast cancer cell line that was implanted into nude mice. In the present study, we evaluated the toxicity of the liposome:p53 complex and the mechanism of this in vivo treatment in reducing tumor growth. Intravenously delivered liposome:p53 complex at dosages sufficient to inhibit human breast cancer in nude mice showed no evidence of toxicity. Clinical chemistries, complete blood counts, and histopathologic examination of various organs from the p53-treated groups did not demonstrate any difference from the control groups. To elucidate the mechanism by which the liposome:p53 complex inhibits cancer, the transfection efficiency of a liposome:chloramphenicol acetyltransferase (CAT) complex into the tumor was determined. Interestingly, less than 5% of the tumor was transfected with a liposome:CAT complex. A mechanism that could account for p53 reduction of tumor size and a low transfection efficiency is inhibition of angiogenesis. After one treatment, we found that the liposome:p53 complex reduced the number of blood vessels in the p53-treated group by approximately 60% compared to the control group (p < 0.001). The close correlation between the antitumor effect of p53 and the reduction of blood vessel density in the tumor suggests that p53 effects are mediated, at least in part, by an antiangiogenesis mechanism.

Animals↗
PubMed1997

Coronary artery bypass graft surgery in Ontario and New York State: which rate is right? Steering Committee of the Cardiac Care Network of Ontario.

BACKGROUND: Previous studies have shown that the rate of coronary artery bypass graft (CABG) surgery is much higher in New York State than in Ontario. OBJECTIVE: To compare the service context and clinical characteristics of patients having CABG surgery in New York and Ontario. DESIGN: Retrospective analysis of data from cardiac surgery registries in New York and Ontario. PATIENTS: All 16,690 patients in New York and 5517 patients in Ontario who had isolated CABG surgery in 1993. MEASUREMENTS: Clinical characteristics of patients having CABG surgery and rates of CABG surgery by coronary anatomy. RESULTS: The overall age-adjusted rate of isolated CABG surgery was 1.79 times (95% CI, 1.74 to 1.85) greater in New York than in Ontario. Patients who had CABG surgery in New York were more likely to be elderly and female and to have recently had myocardial infarction (P < 0.001), whereas patients who had CABG surgery in Ontario were more likely to have had left ventricular dysfunction and severe coronary artery disease (two-vessel disease with proximal left anterior descending disease, three-vessel disease, or left main disease) (P < 0.001). The relative rate of CABG surgery for left main disease was 2.53 times (CI, 2.35 to 2.73) greater in New York than in Ontario but was 8.97 times (CI, 8.01 to 10.06) greater for patients with limited coronary artery disease (one-vessel or two-vessel disease without proximal left anterior descending disease). CONCLUSIONS: The higher rates of CABG surgery in New York are associated with higher rates of CABG surgery among the elderly, women, and patients who recently had myocardial infarction. Potential underservicing in Ontario is suggested by a lower rate of CABG surgery for left main disease; however, the higher rate of CABG surgery in New York is also associated with a strikingly higher rate of surgery in patients with limited coronary disease. Such trade-offs highlight the difficulty of defining an optimal rate of CABG surgery.

Adult↗
PubMed1997

Elevated cytosolic calcium and impaired proliferation of B lymphocytes in type II diabetes mellitus.

Patients with diabetes mellitus have increased susceptibility to infection attributable, at least in part, to defective function of polymorphonuclear leukocytes (PMNLs) and B cells. Certain data suggest that cytosolic calcium ([Ca2+]i) is elevated in various cells in diabetes, and high [Ca2+]i adversely affects cell function. Indeed, the [Ca2+]i of PMNLs of diabetic patients is elevated, and phagocytosis of the PMNLs is impaired. The current study examines whether the [Ca2+]i of B cells is also elevated in diabetes and whether this derangement impairs B cell function. We studied 32 patients with non-insulin-dependent diabetes mellitus (NIDDM) and eight normal subjects. All patients had hyperglycemia (11.6 +/- 0.80 mmol/L) and elevated HbA1c (13.2% +/- 0.99%). The basal levels of [Ca2+]i of the B cells (113 +/- 3.3 nmol/L) were significantly (P < 0.01) higher than the values in normal subjects (85 +/- 1.7 nmol/L). There was a direct and significant correlation (r = 0.88; P < 0.01) between the [Ca2+]i of B cells and the blood levels of glucose. Proliferation of B cells in response to Staphylococcus aureus Cowan I (SAC) was significantly impaired in these patients (7.3 +/- 0.48 x 10(3) cpm v 12.5 +/- 0.61 x 10(3) cpm in normal subjects). Normalization of blood glucose with the hypoglycemic agents, glyburide, was associated with the return of both [Ca2+]i of B cells and their proliferation in response to SAC to normal. The results show that hyperglycemia in type II diabetes mellitus is associated with a significant increase in [Ca2+]i of B cells and with a decrease in their proliferation in response to mitogen. These derangements are reversed after the correction of the hyperglycemia. The data of the current study and those previously reported in PMNLs provide for a new pathogenetic process underlying the dysfunction of these cells in diabetes mellitus.

Adult↗