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Biomedical subjects

A Bhatia

Publications and source records attributed to A Bhatia.

At least 73 records · Page 4Linked to original sources
PubMed1995

Comparison of the effects of exercise and cold pressor test on the vasomotor response of normal and atherosclerotic coronary arteries and their relation to the flow-mediated mechanism.

This study was designed to assess the vasomotor response of coronary arteries to exercise and the cold pressor test, and its relationships with the endothelium-mediated dependent mechanism. Twenty-two patients were entered in the study. Group I was composed of 12 patients with a total cholesterol level < 200 mg/dl associated with angiographically smooth, normal coronary arteries. Group 2 consisted of 10 patients with both a cholesterol level > 240 mg/dl and angiographic luminal irregularities of the left anterior descending coronary artery. Coronary blood flow was assessed by a 0.018-inch tip guidewire during Doppler ultrasonography, and analysis of the coronary arterial dimension of the midportion of the left anterior descending coronary artery was performed by quantitative coronary angiography. Catecholamine concentrations were assessed at the different stages of the protocol. The rate-pressure product increased during both the cold pressure test and exercise (p < 0.001). Coronary blood flow velocity increased during the cold pressor and exercise tests by 24.5 +/- 10% and 72 +/- 42%, respectively (p < 0.001), and by 127 +/- 62% (p < 0.0001) after administration of papaverine. In group 1, the cold pressor test had a more pronounced vasodilating effect on epicardial coronary arteries (+11.2 +/- 16%) compared with group 2 (-2 +/- 9%, p < 0.05). Similarly, exercise had a vasodilating action in group 1 (11.3 +/- 15%) compared with group 2 (-1.9 +/- 8%, p < 0.05). Both responses were highly correlated (r = 0.92, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Surgical correction of pseudo-ainhum in Vohwinkel syndrome.

Vohwinkel syndrome or hereditary mutilating keratodermatitis is a rare condition producing palmoplantar hyperkeratosis and constricting rings of the fingers and toes which can progress to compromise neurovascular function and mobility. Medical treatment with oral retinol derivatives is recommended when its use is not contra-indicated. This paper describes surgical correction of the constricting rings on both hands in a 33-year-old woman affected by this condition.

Adult↗
PubMed1995

The by-pass extensor tendon transfer. A salvage technique for loss of substance of the extensor apparatus in long fingers.

A salvage technique for the treatment of substance loss of the extensor apparatus with some special features is presented. It uses the extensor indicis muscle prolonged with a tendon graft. The tendon is directly attached to the middle phalanx. After surgery, the wrist is immobilized in extension, allowing immediate active mobilization of the PIP joint. The results in five patients are satisfactory.

Adolescent↗
PubMed1995

The posterolateral malleolar flap of the ankle: a distally based sural neurocutaneous flap--report of 14 cases.

The posterolateral malleolar flap is a fasciocutaneous flap designed on the principles of distally based neurocutaneous flaps. It is based distally at the level of the lateral retromalleolar gutter. Elevation of the flap involves the proximal sectioning of the sural nerve, which contributes to its vascularization by reversed flow. This is a very reliable flap, even in patients with distal arterial insufficiency. For this reason, it has emerged, in our experience, as the method of choice in the treatment of heel necrosis. Fourteen cases are reported, of which six were elderly patients.

Adult↗
PubMed1995

Comparison of pleural fluid cytology and pleural biopsy in the evaluation of pleural effusion.

Pleural fluid cytology and pleural biopsy results were studied in 65 cases of pleural effusion. The efficacy of pleural biopsy in diagnosis of neoplastic and non-neoplastic pleural diseases was compared. Of the 24 cases with confirmatory evidence of cancer, 17(70.8%) has positive cytologic findings in pleural fluid, whereas pleural biopsy was diagnostic in only 13 cases (54.1%). For non-malignant pleural effusion in 41 cases 40(97.5%) has a definite diagnosis (tuberculous pleuritis, acute fibrinous pleuritis or hydatid cyst) which could be made by cytology while only 31(75.6%) out of 41 were diagnosed on pleural biopsy. The study indicates that cytologic evaluation of pleural fluid is more efficaceous in the diagnosis of malignant and non-malignant pleural disease than percutaneous pleural biopsy.

Biopsy, Needle↗
PubMed1994

In vitro study of a radiofrequency guidewire aimed at recanalization of totally occluded peripheral arteries.

A novel radiofrequency ablative system (40 msec-train pulses with twenty 200 msec pulses at the carrier frequency of 750 KHz and 1 Hz repetition rate) aimed at recanalizing totally occluded peripheral arteries was investigated by means of in vitro tissue ablation from human postmortem arterial wall samples. The samples were submitted to irradiation with a guidewire 150 cm long, maximum diameter of ceramic tip 0.033 inch positioned perpendicular to the tissue surface in saline, contrast medium or blood using varying generator power. Ablation efficacy was determined as the depth of vaporization per pulse delivered. Electrical current for the train duration was measured as voltage at the 1 ohm-resistor. In saline, the ablation efficacy increased from 8 to 65 microns/pulse with generator power increasing from 11 W to 27.5 W. There was no significant difference in the ablation efficacy between saline and blood. In contrast medium, the ablation efficacy was significantly lower. For the same generator power, the electrical current varied during the ablation procedure from 1.3 +/- 0.2 A at the beginning of the procedure to 1.1 +/- 0.2 A after the first pulses and to 2.0 A before artery wall perforation occurred. Neither tissue ablation nor current variations were observed when radiofrequency energy was emitted on calcified tissue. The diameter of craters was 0.89 +/- 0.1 mm (range: 0.85-0.96 mm). No major thermal injury such as carbonization or charring was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Cadaver↗
PubMed1994

A phase I trial of intrapleural recombinant human interferon alpha (rHuIFN alpha 2b) in patients with malignant pleural effusions.

The use of intrapleural sclerosing agents to control reaccumulation of pleural fluid in patients with malignant effusions has been widely investigated. A phase I trial of intrapleural recombinant human interferon alpha (rHuIFN alpha 2b) was initiated to determine the toxicity and maximal tolerated dose in this group of patients. rHuIFN alpha 2b was instilled as a single dose following chest tube (15/16) or percutaneous (1/16) drainage of cytologically proven malignant effusions. Doses of rHuIFN alpha 2b were escalated from 25 x 10(6) to 200 x 10(6) U/m2 in cohorts of three to four patients. Toxicity was mild to moderate, and included chills, fever and chest pain, and resembled that produced by systemic administration of rHuIFN alpha 2b. Dose-limiting toxicity occurred at 200 x 10(6) U/m2 and consisted of hepatic enzyme elevations and renal failure. Partial control of the effusions was noted in two patients, with two additional patients having stable disease. Phase II trials of rHuIFN alpha 2b should utilize up to 150 x 10(6) U/m2 for intrapleural instillation.

Adult↗
PubMed1994

Molecular cloning, characterization, and expression in Escherichia coli of iron superoxide dismutase cDNA from Leishmania donovani chagasi.

A cDNA corresponding to superoxide dismutase (SOD; EC 1.15.1.1.) was isolated from a Leishmania donovani chagasi (L. d. chagasi) promastigote cDNA library, using PCR with a set of primers derived from conserved amino acids of manganese SODs (MnSODs) and iron SODs (FeSODs). Comparison of the deduced amino acid sequences with previously reported SOD amino acid sequences revealed that the L. d. chagasi 585-bp open reading frame had considerable homology with FeSODs and MnSODs. The highest homology was shared with prokaryotic FeSODs. The coding region of L. d. chagasi SOD cDNA has been expressed in fusion with glutathione-S-transferase, using an Escherichia coli mutant, QC779, lacking both MnSOD and FeSOD genes (sodA and sodB). Staining of native polyacrylamide gels for SOD activity of Leishmania crude lysate and the recombinant SOD revealed that both had SOD activity that was inactivated by 5 mM hydrogen peroxide but not by 2 mM potassium cyanide, which is indicative of FeSOD. The recombinant enzyme also protected E. coli mutant QC779 from paraquat toxicity. This indicated that the glutathione-S-transferase peptide does not interfere with the in vivo and in vitro activities of the recombinant SOD. Cross-species hybridization showed that FeSOD is highly conserved in the Leishmania genus. Interestingly, the hybridization pattern of the FeSOD gene(s) coincided with other classification schemes that divide Leishmania species into complexes. The cloning of FeSOD cDNA may contribute to the understanding of the role of SODs in Leishmania pathogenesis.

Amino Acid Sequence↗
PubMed1994

Functional specificity for salmon gonadotropin-releasing hormone (GnRH) and chicken GnRH-II coupled to the gonadotropin release and subunit messenger ribonucleic acid level in the goldfish pituitary.

GnRH is the key regulator of reproduction in the vertebrates. In this study, we investigated the release and synthesis of maturational gonadotropin hormone (GTH-II) stimulated by native GnRH forms, salmon GnRH (sGnRH) and chicken GnRH-II (cGnRH-II), in the goldfish pituitary. The experimental approach was to study the differences between desensitization induced by sGnRH and cGnRH-II administered in homologous and heterologous fashion. Pulsatile alternate treatments with sGnRH and cGnRH-II (i.e. sGnRH/cGnRH-II or cGnRH-II/sGnRH) at 10(-8) M (every 30 min) resulted in a lower degree of desensitization compared with homologous treatments with either sGnRH or cGnRH-II (sGnRH/sGnRH or cGnRH-II/cGnRH-II), or when combined together (sGnRH+cGNRH-II). We also investigated the effects of continuous treatments with sGnRH and cGnRH-II, administered in a homologous or heterologous fashion. Increasing concentrations of either sGnRH or cGnRH-II (10(-8)-10(-6) M) administered continuously (60 min) in a homologous fashion resulted in significant desensitization of the pituitary GTH-II release. Alternate continuous treatments with sGnRH and cGnRH-II (i.e. sGnRH/cGnRH-II/sGnRH or cGnRH-II/sGnRH/cGnRH-II) resulted in lower degree of desensitization compared to homologous treatments, particularly at lower doses. We further investigated the effects of sGnRH and cGnRH-II on GTH-II beta and GTH-II alpha subunit messenger RNA (mRNA) levels in the goldfish pituitary. In sexually regressed animals, sGnRH treatment (4 micrograms/fish) increased the accumulation of GTH-II beta and GTH-II alpha mRNA, whereas cGnRH-II treatment was without effect. In sexually mature animals, however, both cGnRH-II and sGnRH stimulated accumulation of GTH-II beta and GTH-II alpha mRNA, with cGnRH-II exerting a greater effect on GTH-II subunit mRNA production. These results suggest a differential control of GTH-II subunit gene expression or mRNA stabilization by sGnRH and cGnRH-II in the goldfish pituitary based on the stage of gonadal recrudescence. In general, the present findings support the hypothesis that sGnRH and cGnRH-II regulate the release and synthesis of GTH-II through different receptor-effector mechanisms in the goldfish pituitary.

Animals↗
PubMed1994

Morphological & immunohistochemical spectrum in anorectal malignancies.

The morphological features of 62 anorectal malignancies diagnosed on sigmoidoscopic biopsy were studied. On haemotoxylin and eosin staining the tumours were diagnosed as adenocarcinomas (43), squamous cell carcinoma (12), malignant melanoma (3), carcinoid (2), clear cell carcinoma (1) and poorly differentiated carcinoma (1). PAS Alcian blue, Grimelius silver stain, AgNOR and immunohistochemical stain for carcinoembryonic antigen (CEA) and human papilloma virus (HPV) were done to further categorise these tumours. The ages of the patients varied from 18 to 77 yr (mean 43.7 yr) and the male: female ratio was 2:1. PAS Alcian blue staining was helpful in differentiating mucinous from non-mucinous adenocarcinomas and reclassifying one poorly differentiated carcinoma as mucin secreting adenocarcinoma. Also, it clearly identified pagetoid spread in two cases of adenocarcinomas. Grimelius silver stain was strongly positive in melanomas and neuroendocrine tumours. Basal silver staining was visualised in metaplastic foci but was absent in dysplastic epithelium. AgNOR counts may be considered useful in differentiating melanomas (high counts) from spindle cell variant of squamous carcinomas (low counts). High AgNOR counts and strong Grimelius positivity in clear cell carcinoma suggested its melanotic origin. Immunostaining for CEA and HPV were of limited value. CEA was positive in the majority of the adenocarcinomas while HPV could only be demonstrated in two squamous cell carcinomas.

Adolescent↗
PubMed1994

An evaluation of the S-100 stain in the histological diagnosis of tuberculoid leprosy and other granulomatous dermatoses.

Forty biopsies of granulomatous dermatoses, 12 of which were tuberculoid leprosy (TL), were studied for patterns of nerve twig distribution using an immunoperoxidase technique for S-100 protein. Four distinct patterns of nerve twigs were identified: 1) within granulomas, 2) between granulomas, 3) within and between granulomas, and 4) undetectable nerve twigs in an adequate biopsy. Pattern 4 was seen exclusively in TL (p < 0.05). The other patterns occurred in nonleprosy dermatoses as well, suggesting that pattern 4 is the best indicator toward a diagnosis of TL. The granules of mycetoma and Mycobacterium leprae also stained positively with the S-100 stain.

Diagnosis, Differential↗
PubMed1993

Successful aortic balloon valvuloplasty in critical aortic stenosis with shock.

Emergency balloon valvuloplasty was performed in a 42 year old male with critical aortic stenosis, severe congestive heart failure, and shock. Hemodynamic and clinical improvement occurred and he underwent elective aortic valve replacement. Balloon aortic valvuloplasty may provide a "bridge" to aortic valve replacement in patients with critical aortic stenosis and shock.

Adult↗
PubMed1993

Isolation & cryo-preservation of human foetal articular chondrocytes.

An attempt to determine the ideal temperature and duration of storage of human foetal chondrocytes yielded highly cellular preparations with no alteration in morphology or loss of viability. Initial digestion with activated papain was followed by incubation in 0.5 per cent collagenase. Trypan blue exclusion test revealed a viability count of 95-99 per cent and radioactive thymidine uptake a corresponding labelling index. On TEM no subcellular damage was evident. The isolated viable chondrocytes were further banked at varying temperatures of +4 degrees, -4 degrees, -30 degrees, -79 degrees and -196 degrees C, in Eagles MEM with 10 per cent dimethyl sulfoxide. Post storage morphology and viability of these cells, thawed after durations of 20 h, 1 wk, 1, 2, 3, 4 and 6 months, were compared with prestorage readings in an attempt to define the ideal temperature for banking. Storage in liquid nitrogen at -196 degrees C demonstrated excellent preservation even at the end of six months with minimal subcellular change. Electron microscopy and labelling index were found to be superior to Trypan blue exclusion test in assessing the stored chondrocytes for retention of their functions.

Cartilage, Articular↗
PubMed1993

Fine needle aspiration cytology in the diagnosis of mass lesions of the salivary gland.

Fine needle aspiration was performed on 101 patients with mass lesions of the salivary gland. In 98 patients satisfactory material was obtained. This could be correlated with the histology done in 54 cases. There were 12 inflammatory lesions; 52 benign and 34 malignant tumors. Of the malignant tumors 32 were primary salivary tumors and one case each of lymphoma and leukemia. The overall accuracy was 97 per cent. There were no false positives but one false negative diagnosis. In two cases there was a discrepancy of tumor type between the cytology and histopathology; these were due mainly to sampling errors. This study documents that cytomorphology can characterise a wide range of histologically described lesions including the rare epithelial myoepithelial tumor. The application of stringent criteria in the diagnoses of salivary lesions, even inflammatory conditions like chronic sialadenitis, avoids over-diagnosis. Both inflammatory and neoplastic lesions may be cystic. These cystic lesions may prove to be a pitfall in cytology. Reaspiration of cystic lesions especially from residual solid areas greatly improves accuracy. We suggest that a fore-knowledge of tumor type preoperatively greatly reduces surgery in clinically questionable salivary lesions.

Adolescent↗