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Biomedical subjects

K C Rao

Publications and source records attributed to K C Rao.

At least 19 recordsLinked to original sources
PubMed1995

Intratentorial lipomas with Meckel's cave and cerebellopontine angle extension.

An unusual case of bilateral intratentorial lipomas with extension into Meckel's caves and the cerebellopontine angle is described. Surgical and histopathologic correlation demonstrate that the lipoma encased the trigeminal nerve in Meckel's caves. The origin of the lipoma from the anteromedial margins of the tentorium is discussed and correlated with a recently proposed theory for the development of intracranial lipomas.

Adult↗
PubMed1993

Bacterial aerosol emission rates from municipal wastewater aeration tanks.

In this report we describe the results of a study conducted to determine the rates of bacterial aerosol emission from the surfaces of the aeration tanks of the Metropolitan Water Reclamation District of Greater Chicago John E. Egan Water Reclamation Plant. This study was accomplished by conducting test runs in which Andersen six-stage viable samplers were used to collect bacterial aerosol samples inside a walled tower positioned above an aeration tank liquid surface at the John E. Egan Water Reclamation Plant. The samples were analyzed for standard plate counts (SPC), total coliforms (TC), fecal coliforms, and fecal streptococci. Two methods of calculation were used to estimate the bacterial emission rate. The first method was a conventional stack emission rate calculation method in which the measured air concentration of bacteria was multiplied by the air flow rate emanating from the aeration tanks. The second method was a more empirical method in which an attempt was made to measure all of the bacteria emanating from an isolated area (0.37 m2) of the aeration tank surface over time. The data from six test runs were used to determine bacterial emission rates by both calculation methods. As determined by the conventional calculation method, the average SPC emission rate was 1.61 SPC/m2/s (range, 0.66 to 2.65 SPC/m2/s). As determined by the empirical calculation method, the average SPC emission rate was 2.18 SPC/m2/s (range, 1.25 to 2.66 SPC/m2/s). For TC, the average emission rate was 0.20 TC/m2/s (range, 0.02 to 0.40 TC/m2/s) when the conventional calculation method was used and 0.27 TC/m2/s (range, 0.04 to 0.53 TC/m2/s) when the empirical calculation method was used.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1992

Action of hydrazine drugs in tumor-free and 1,2-dimethylhydrazine-treated male rats.

In order to evaluate possible carcinogenesis, young adult male Sprague-Dawley rats were fed diets of hydralazine, phenelzine, and isoniazid at levels of 0.020-0.035% for 87 weeks. Hydralazine and isoniazid were also tested by the subcutaneous (sc) route at weekly dosages of 17 and 83 mg/kg, respectively, in both intact and partially hepatectomized rats, but many succumbed after 7 to 49 weeks of treatment. Gastrointestinal lesions were absent and, of the miscellaneous changes, sc lesions occurred sporadically among the control and drug-treated groups. As a further criterion, male weanlings were placed on the diets and, starting on day 15, 1,2-dimethylhydrazine (DMH) was injected sc at 9.0 mg/kg once weekly for the first 7 weeks and twice per week for a total of 23 treatments. The rats were killed 22 weeks after the last injection, at which time colon adenocarcinomas were observed in over 80% per group, the total number being significantly greater for the isoniazid group due to heightened tumor occurrence at the distal colon. The tumor number in the descending colon for phenelzine was also increased but the overall score, as with the hydralazine group, was in the range of the DMH injected controls. Small intestinal adenocarcinomas were lower in number and involved fewer rats on the hydralazine and phenelzine diets as compared to the isoniazid and control groups. Based on the current data, it is concluded that on long term exposure of DMH treated rats to the monoamine oxidase inhibitors, hydralazine and phenelzine are not cocarcinogenic, whereas isoniazid enhances colon carcinogenicity.(ABSTRACT TRUNCATED AT 250 WORDS)

1,2-Dimethylhydrazine↗
PubMed1988

Carcinoid tumor with intradural spinal metastases.

A case of spinal intradural metastasis from a carcinoid tumor is reported. The case is of interest due to the rarity of central nervous system involvement by these tumors and the long latency period of the patient's presentation.

Carcinoid Tumor↗
PubMed1988

Quantitation and pattern of parenchymal lung injury in blunt chest trauma. Diagnostic and therapeutic implications.

Sixty-nine patients with nonpenetrating pulmonary trauma were studied by chest computed tomography (CT) within 24 hours of admission. The percentage of air-space filling was quantitated and compared with the requirement for ventilatory support. Pulmonary intraalveolar hemorrhage always is gravity dependent originating at the site of injury. Utilizing CT, the patients' pulmonary status was classified into three separate clinicoradiologic groups: Grade I injury (less than 18% air-space filling, no ventilator support required), Grade II injury (18-28% air-space filling, ventilator support sometimes required), and Grade III injury (greater than 28 air-space filling, ventilator support always required). The CT quantitation correlated with clinical functional studies and was useful in the therapeutic management of nonpenetrating lung injury.

Adolescent↗
PubMed1987

Computed tomography of Toxocara canis endophthalmitis.

Many lesions, termed pseudogliomas, may mimic the appearance of retinoblastoma, both clinically and on computed tomography. The appearance of Toxocara canis endophthalmitis on computed tomography is presented. The role of computed tomography in the evaluation of patients presenting with leukokoria is discussed.

Ascariasis↗
PubMed1985

Imaging modalities of craniosynostosis with surgical and pathological correlation.

Premature fusion of the sutures of the skull has been extensively analyzed and several diagnostic imaging modalities have been proposed. Radiographic, scintigraphic and computed tomographic features of craniosynostosis have been reported. This study was initiated (a) to determine the value and accuracy of plain skull radiography, skull scintigraphy and cranial CT; and (b) to determine the optimal imaging modality for the evaluation of a clinically suspected craniosynostosis. The study is based on 36 patients with clinical suspicion of craniosynostosis who underwent craniectomy and cranioplasty. One hundred and three sutures were pathologically and/or surgically evaluated. The overall accuracy rate for skull radiography was 89%, skull scintigraphy, 66%, and cranial CT, 94%. Routine skull series are adequate in the majority of cases of craniosynostosis. Skull scintigraphy is less accurate, more costly, and has a limited role in the evaluation of craniosynostosis. Cranial CT should be reserved for those cases in which the findings in the routine skull series are not clearly positive or negative, or in cases of more complex craniofacial anomalies.

Craniosynostoses↗
PubMed1985

Cholesterol granuloma of the petrous apex and sphenoidal sinus: a case report.

A case of a cholesterol granuloma located in the petrous apex and eroding into the sphenoidal sinus is reported. Cholesterol granuloma is thought to occur when pneumatized cells in the temporal bone become obstructed. Although usually occurring in the middle ear, it can occur in the petrous apex. The diagnosis and surgical management are discussed.

Cholesterol↗
PubMed1985

Regression analysis of total fatty acids from human whole brain according to age and sex.

Total fatty acids processed from whole brain samples removed at autopsy from men and women, 26-87 years of age, were esterified, the methyl esters analyzed by gas chromatography, and the respective profiles deduced. In the study of the effect of age and sex in relation to the fatty acid levels, regression analysis was applied to smoothened data to take care of extraneous effects or variables. Toward this end, five age groupings were formed and the regression relationships explored for each group per sex. Generally, the saturated homologs occurred in higher amounts among males of advancing age but decreased with age among females. This effect stemmed from the even-carbon acids. For the unsaturated fatty acids, the reverse behavior appeared evident. For the prominent acids, 16:0 and 18:0, the differences were moderately significant for cases 50 years and older, for 18:2, significance based on either sex was noted with all age groups.

Adult↗
PubMed1984

Vascular studies in the preoperative evaluation of pituitary adenomas before transsphenoidal surgery.

The transsphenoidal approach is being increasingly utilized in the surgical treatment of pituitary microadenoma. Even with high-resolution and dynamic computed tomography (CT) scanning, subtle vascular anatomic variants and other vascular anomalies involving the parasellar carotid arteries cannot always be clearly defined. Five cases are described in which evaluation by digital intravenous subtraction angiography or standard carotid arteriography provided useful preoperative information before transsphenoidal surgery. The implications of these findings are discussed.

Adenoma↗
PubMed1984

Role of computed tomography in symptomatic vertebral hemangiomas.

Vertebral hemangioma, although a benign lesion, can result in neurologic deficit. Computed tomography is useful in demonstrating the extension of the hemangioma into the posterior neural arch and epidural space. Computed tomography after intravenous contrast administration is useful in evaluating the vascular nature of the lesion and is a useful technique before surgery or spinal angiography.

Female↗
PubMed1984

Intramedullary canine spinal cord tumor model.

The development of a transplantable model brain tumor in the neonatal dog, the adaptation of the tumor to tissue culture, and the successful growth of the tumor in adult mongrel dogs has been adapted to producing similar tumors in the thoracic spinal cord of the adult dog. Ten adult dogs, weighing 4 to 25.4 kg each, were subjected to formal laminectomy. The tumor cell suspension was injected by hand with a Hamilton syringe at two or three sites over a distance of 1 cm; each site received an injection volume to 0.02 to 0.05 cc of the cell suspension after the dura had been opened. Immediately after injection the field was copiously irrigated and the puncture area sealed with a single drop of ethyl cyanoacrylate. Tumor cells for injection were obtained by thawing ampules stored at -195 degrees C in a mixture of 10% dimethyl sulfoxide and RPMI 1640 culture medium. Cells were resuspended in Hank's balanced salt solution and 15% fetal calf serum on ice. Solutions had 90% cell viability, and animals received a dose in the range of 3 to 13 X 10(6) cells. Eight animals developed tumors and became paraparetic on the 9th to 14th postinjection day. Metrizamide myelography in three animals revealed complete blocks; two animals underwent spinal computerized tomography (CT) and demonstrated syringohydromyelia. Histology revealed the tumors to be highly vascular primitive neoplasms that invaded the surrounding cord. This spinal cord tumor model is large enough to be operated on, studied by CT and myelography, and subjected to pharmacological, electrophysiological, and blood flow study.

Animals↗
PubMed1983

Intracranial venous aneurysms: vein of Galen and other similar vascular anomalies.

Aneurysmal dilatation of the vein of Galen is peculiar to arteriovenous malformation around the midbrain. Similar venous aneurysms may rarely occur in other regions. This paper deals with the radiographic findings in three cases of vascular malformation associated with giant venous aneurysms. The pathophysiology resulting in aneurysmal venous dilatation is discussed based on our material and those previously reported.

Brain↗
PubMed1983

Microglioma--unusual computed tomographic appearance and course of neoplasm.

Microglioma accounts for 0.8-1.5% of primary brain tumors. Eight cases of primary lymphoma of brain are presented. 50% of the patients demonstrated unusual computed tomographic appearances. These patients were divided into three groups depending on clinical outcome. Survival seems to be related to treatment modality. Longest survival times were in patients treated with radiation alone or radiation following biopsy.

Adult↗
PubMed1982

Basal ganglia calcification in the neonate.

Calcification of the basal ganglia developed following intracranial hemorrhage in a neonate recovering from severe perinatal asphyxia. Cranial computed tomography is useful in demonstrating the anatomic distribution of dystrophic calcification in regions previously involved by hemorrhage. The demonstration of hemorrhage or hemorrhagic infarction with CT may help to verify the association of basal ganglia calcification with birth anoxia.

Adult↗
PubMed1982

Epidermoid tumor of the fourth ventricle: use of metrizamide-computed tomography.

This report describes two cases of epidermoid tumor of the fourth ventricle diagnosed with metrizamide computed tomography. They both presented as a low-density lesion in the region of the fourth ventricle on computed tomography. They did not show any enhancement after intravenous injection of contrast medium and had no hydrocephalus. Metrizamide-enhanced computed tomography demonstrated the irregular fourth-ventricular filling defect characteristic of epidermoid tumors.

Adult↗