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Biomedical subjects

S K Chakravarty

Publications and source records attributed to S K Chakravarty.

At least 19 recordsLinked to original sources
PubMed1996

Radiolabeled denatured RBC scintigraphy in autologous splenic transplantation.

An 18-year-old man underwent surgery for blunt abdominal trauma requiring a total splenectomy. Heterotopic splenic autotransplantation was done in the omentum. Immediate platelets counts, cell morphology, and serum immunoglobulin levels were suggestive of impaired splenic function. Radiolabeled denatured RBC splenic imaging showed evidence of functioning autotransplanted splenic tissue in the omentum. The blood parameters were found to be normal 4 weeks after transplant. Radionuclide denatured RBC imaging has been found to be useful in the localization of functional autotransplanted splenic tissue.

Abdominal Injuries↗
PubMed1996

Scintigraphic diagnosis of gastrointestinal bleeding with 99Tcm-dextran.

Intravenously administered dextran is used clinically as a plasma expander. The aim of this study was to assess the use of 99Tcm-dextran in the diagnosis of gastrointestinal (GI) blood leaks. Twenty-one patients with GI blood loss underwent 99Tcm-dextran scintigraphy, 17 of whom were found to be positive. Pathologic or 99Tcm-RBC (red blood cell) blood pool correlation was possible in 15 cases, while 2 were unconfirmed. No case had a positive 99Tcm-RBC blood pool study and a negative 99Tcm-dextran study. Images obtained with 99Tcm-dextran were generally better than those with 99Tcm-RBC. This agent may have several other advantages over 99Tcm-RBC blood pool and 99Tcm-sulphur colloid scintigraphy for detecting GI blood loss.

Adult↗
PubMed1994

Differentiation of malignant and degenerative bone lesions using dexamethasone interventional 3- and 24-hour bone scintigraphy.

Seventy-seven adult patients with suspected skeletal metastases were divided into two groups. In group A (n = 30), following intravenous administration of 20 mCi (740 MBq) of technetium-99m methylene diphosphonate (99mTc-MDP), 3- and 24-h scintigraphy of bone lesions was performed. The 24/3 h lesion to bone background radiouptake ratio (RUR) was calculated for each lesion. In group B (n = 47), the same procedure was followed with dexamethasone intervention (10 mg in 24 h) following the 3-h acquisition. In group A, after determination of the critical point, malignant and degenerative bone lesions could be separated with a sensitivity, specificity and accuracy of 0.76, 0.72 and 0.73, respectively. The mean RUR of the malignant lesions was 1.20 +/- 0.23, and that of the benign lesions, 0.95 +/- 0.15. In group B cases, significantly increased sensitivity, specificity and accuracy of 0.87, 0.94 and 0.92, respectively, were found (P < 0.001). The mean RUR of the malignant lesions was 1.48 +/- 0.34, and that of degenerative lesions, 0.88 +/- 0.19. Dexamethasone interventional bone scintigraphy seems to be a new cost-effective method for differentiating malignant from degenerative bone lesions using the RUR.

Bone Diseases↗
PubMed1990

Differentiation between suppressed thyroid tissue and thyroid hemiagenesis with Tc-99m pertechnetate radionuclide angiography.

Tc-99m pertechnetate thyroid angiography was performed on 62 patients who had unilateral thyroid enlargement and no radionuclide uptake in the contralateral lobe in an attempt to differentiate suppressed thyroid tissue from thyroidal hemiagenesis. In 55 cases of toxic, autonomous functioning thyroid nodules, the suppressed contralateral lobe was unequivocally demonstrated, the flow study showing tracer coursing through this tissue in the sequential arterial images. No arterial flow was demonstrable on the rapid sequence imaging in the agenetic lobe in seven patients who had thyroidal hemiagenesis. Radionuclide thyroid angiography appears a safe, simple, and accurate one-step study for distinguishing between suppressed thyroid tissue and thyroid hemiagenesis and precludes the requirement for additional studies, such as the thyrotropin stimulation test and Tl-201 scintigraphy.

Adult↗
PubMed1989

Technetium-99m radiocolloid scintigraphy, planar and SPECT red blood cell imaging and ultrasonography in diagnosis of hepatic hemangioma.

Technetium-99m planar sulfur colloid scintigraphy, red blood cell imaging and ultrasonography were performed in eighteen patients of hepatic hemangioma to evaluate their diagnostic utility. Radiocolloid scans detected fourteen hemangiomas in 12 patients as focal hepatic defects but missed 9 lesions smaller than 2.5 cm in the other 6 patients, accounting for a 61% sensitivity. All 23 lesions were avascular or normovascular on radionuclide flow study. Serial planar red blood cell scintigraphy showed characteristic gradually increasing focal isotopic accumulation in the 14 hemangiomas which had identifiable cold areas on the radiocolloid study. One of 6 patients with normal radiocolloid scan also showed the typical increasing blood pool pattern of hemangioma, five had normal planar scans till 1 1/2 hours. SPECT red blood cell imaging in these 5 patients detected an additional seven hemangiomas. All 7 lesions were smaller than 2.5 cm. One 1.5 cm hemangioma was missed on both planar and SPECT red blood cell imaging. Region of interest ratios in SPECT transaxial images confirmed gradually increasing concentration of labeled red blood cells in the lesions. Ultrasonography detected 22 of the 23 hemangiomas. Ten were hyperechoic, average size 2.25 cm. Twelve were of mixed pattern, generally larger, average size 7.2 cm. Sonography is useful in the detection of hepatic hemangiomas as a focal mass lesion, but the variable sonographic appearance precludes a definite pathological diagnosis. Technetium-99m red blood cell imaging appears a sensitive technique in detection of hepatic hemangioma, with SPECT being especially useful in locating smaller lesions. The addition of useful in locating smaller lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Seroepidemiological study of Japanese encephalitis in Dimapur, Nagaland.

A seroepidemiological study of Japanese encephalitis (JE) in Dimapur, Nagaland was carried out following an outbreak of the disease between July, 1985 and February, 1986. Altogether 50 persons were affected with 30 (60 per cent) deaths. The attack and death rates per 1000 were more in Nagas viz. 0.55 and 0.34 than non-Nagas viz. 0.33 and 0.20 respectively. All ages and both sexes were affected. Of the nine mosquito species encountered Culex vishnui showed the highest density (44.5/MH). Culture of mosquito pool did not yield any viral agent. A total of 311 serum samples comprising 95 humans, 166 animals and 50 birds were tested for the presence of haemagglutination inhibition (HI) antibodies against Chikungunya and three flavirus antigens, viz. JE, WN and DEN-2. The overall flavivirus HI antibody in humans was positive in 26 (27.3 per cent) almost identical to JE antibody prevalence. The per cent positivity of HI antibodies to JE, WN and DEN-2 were 42.2 per cent, 22.2 per cent and 13.3 per cent in the affected and 14.2 per cent, 10 per cent and 6 per cent in the unaffected area. The activity of Alpha (Chikungunya) virus though very low was significantly higher (chi 2 = 5.57) in the affected area. The prevalence of JE antibody was 77.7 per cent in dogs, 52 per cent in cattle, 34 per cent in pigs and 21.1 per cent in goats. Of the five species of birds, flavivirus and JE antibodies were detected in 21.4 per cent pigeons and 22.2 per cent heron egrettes. Neutralisation test established the distinct role of JE virus over other related flavivirus antigens.

Adolescent↗
PubMed1984

Hypolipidemic effect of garlic and thyroid function.

Male Sprague-Dawley rats were maintained on cholesterol and garlic oil for 12 weeks. Cholesterol induced hyperlipidemia was controlled by garlic feeding. Garlic treatment did not alter the concentrations of circulating thyroid hormones and thyroidal uptake of radioiodine. The results indicate that the hypolipidemic effect of garlic is probably not mediated through the thyroid.

Animals↗
PubMed1979

DEAE-silica gel and DEAE-controlled porous glass as ion exchangers for isolation of glycolipids.

DEAE-silica gel and DEAE-controlled porous glass have been used for the quantitative isolation of gangliosides and neutral glycosphingolipids from animal tissues and cells. A direct comparative study between DEAE-silica gel, DEAE-controlled porous glass and DEAE-Sephadex was made; the results indicated that DEAE-silica gel is preferable to the other two ion exchangers. DEAE-silica gel has also been found to be suitable for the fractionation of ganglioside mixtures.

Adult↗