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Biomedical subjects

B K Rao

Publications and source records attributed to B K Rao.

At least 55 records · Page 3Linked to original sources

Color flow Doppler sonography of the abdomen.

This paper reviews recent developments in color flow Doppler sonography of the abdomen reported from October 1989 to September 1990. Areas of focus include instrumentation and technical considerations, and current clinical applications.

Abdomen↗

An immunohistochemical study of fibrous papule of the nose: 25 cases.

Twenty-five cases of fibrous papule of the nose were studied by light microscopy and by immunohistochemistry using a panel of 4 cell markers. These included polyclonal antibodies against S100 protein and Factor XIII-a (FXIII-a), and 2 monoclonal antibodies, MAC 387 which labels monocyte derived macrophage cells and Ulex Europaeus Agglutinin-1 (UEA-1) a pan endothelial cell marker. An increase in the number of S100 protein positive cells, particularly in the upper dermis, was observed in 3 lesions. Melanin was identified in phagocytes in the superficial dermis in 6 lesions, including those with S100 protein positive cells. In all of the papules there was a marked increase in FXIII-a labelling of dendritic connective tissue cells, including spindle, stellate and multinucleate stellate cells. Immunoreactivity with FXIII-a was especially strong in the increased mononuclear dendritic cell population (greater than 80%) seen in the mid- and upper dermis. However, only 15% of the larger multinucleate stellate cells were immunostained with FXIII-a. The results achieved with markers to the macrophage cell series (MAC 387) or endothelial cells (UEA-1) showed no significant increase in labelling of the dermal cell population compared to normal skin taken from the nose. Our study suggests that fibrous papule of the nose, a lesion of uncertain histogenesis, probably represents a proliferative reactive process consisting mainly of dermal dendritic cells as identified by FXIII-a in most of the lesions. There is some evidence that a small percentage of the dendritic cells may represent involuted naevi and be of melanocytic origin.

Antibodies, Monoclonal↗

Massive jugular and dural sinus reflux associated with cerebral death.

Radionuclide cerebral angiograms demonstrated massive jugular venous reflux in two children with clinical and electroencephalographic evidence of cerebral death. With an antecubital injection, the tracer flowed up the jugular vein, through the transverse dural sinus, and down the contralateral jugular vein. No arterial flow was seen. We hypothesize that this unusual pattern reflects the absence of normal antegrade flow through the venous system. The appearance of jugular reflux is distinct from arterial flow and should not be confused with it. These cases illustrate communication between the systemic venous system and the dural sinuses. Although this pattern in not diagnostic of cerebral death, the appearance of radiotracer in the dural sinuses does not establish the presence of cerebral perfusion.

Brain Death↗

Correlative radiographic, scintigraphic, and histological evaluation of exostoses.

We reviewed the cases of twenty-four patients with solitary or multiple exostoses to correlate their radiographic, scintigraphic, and histological evaluations. We studied twenty-five excised lesions, two of them exostotic chondrosarcomas, from twenty-two patients. There were two patterns of bone-scan activity and there was a direct correlation between enchondral bone formation and radionuclide uptake in all patients, both skeletally immature and mature. So-called quiescent lesions--those with inactive scans--were those that lacked histological evidence of enchondral bone formation. Those with increased uptake--active exostoses--all demonstrated active formation of enchondral bone. Evidence of active exostotic growth could be demonstrated on bone scans well beyond the time of skeletal maturity. The bone scan did not qualitatively differentiate the benign active exostoses from the two lesions with malignant degeneration. Increased uptake related to enchondral bone formation was a feature of both. An inactive scan, however, seemed to exclude the possibility of malignant degeneration in the exostosis.

Adult↗

Dual radiopharmaceutical imaging in congenital asplenia syndrome.

Asplenia was suspected in one patient with combined immunodeficiency syndrome and 5 with congenital cardiac anomalies who had Howell-Jolly bodies on peripheral blood smears. 99mTc-sulfur colloid scans were equivocal for absence of the spleen. When they were compared with the 99mTc-PIPIDA hepatobiliary images, a discrepancy in organ morphology between the two scans indicated that the spleen was present, whereas similarity of the two images suggested asplenia. This procedure was useful in establishing asplenia in 4 patients and confirming the presence of a rudimentary or ectopic spleen in 2 others. Unequivocal demonstration of the spleen on the sulfur colloid scans makes the hepatobiliary study unnecessary, while unequivocal demonstration of a normal-appearing liver without splenic activity may warrant a tagged red-cell study for a more complete evaluation.

Erythrocyte Inclusions↗

Hepatic and splenic scintigraphy in idiopathic systemic amyloidosis.

Technetium-99m sulfur colloid (SC) and Technetium-99m pyrophosphate (PYP) scintigrams in a patient with idiopathic systemic amyloidosis were abnormal. Hepatic SC distribution was nonhomogeneous. Spleen showed reduced SC uptake and a large focal defect at its upper pole. Splenic localization of PYP was seen on a bone scan. On histologic examination the abnormal scintigraphic sites showed heavy amyloid deposition. Splenic localization of skeletal radiotracer due to amyloidosis has not been previously reported.

Amyloidosis↗

Influence of respiratory maneuvers on jugular venous reflux.

The cause of jugular venous reflux during a radionuclide cerebral angiogram is uncertain. The authors describe a patient in whom physiologic respiratory maneuvers had a profound influence on the jugular venous reflux during cerebral radionuclide angiography. The massive jugular reflux was abolished by intravenous injection of a radiotracer bolus during inspiration. When brain blow data are difficult to interpret because of reflux, the authors suggest that radiotracer be administered intravenously during inspiration.

Cerebral Angiography↗

Dissociation of reticuloendothelial cell and hepatocyte functions in alcoholic liver disease: a clinical study with a new Tc-99m-labeled hepatobiliary agent.

Tc-99m-sulfur colloid scintigrams were abnormal in four patients with hepatic dysfunction due to chronic alcohol abuse. Minimal uptake of radiocolloid in the liver suggested local reticuloendothelial (RE) cell failure. Imaging with a new hepatobiliary agent, Tc-99m-PIPIDA, revealed rapid hepatic accumulation and excretion of radiotracer with adequate visualization of the organ. Scintigraphic findings in these patients indicated a dissociation of hepatocyte and RE cell functions. Demonstration of adequate hepatocyte function with severe RE failure in alcoholic liver disease using a Tc-99m-labeled hepatobiliary agent has not been previously reported.

Adult↗