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Biomedical subjects

V R Challa

Publications and source records attributed to V R Challa.

At least 55 records · Page 3Linked to original sources
PubMed1988

Relationship between flow cytometric features and clinical behavior of meningiomas.

Meningiomas have a wide range of biological potential and clinical behavior. Histological findings are helpful in recognizing the malignant potential of a given tumor, but often fail to correlate with gross features, liability of recurrence, and extent of associated cerebral edema. To find alternate approaches to improve the correlation between biological and clinical behavior, 20 meningiomas were studied by flow cytometry (FC), an assessment that has been applied to meningiomas previously. Such FC features as DNA index (DI) and proliferative index (PI, %G2 + %S) were correlated with size, location, brain invasion, associated edema, and recurrence. Tumors with severe edema had significantly higher PIs (19.5 +/- 4.1) than those with moderate (12.6 +/- 4.5) or minimal (8 +/- 0) edema (P less than 0.05). The PI was greater than 16 in those tumors that recurred (n = 3) or invaded the brain (n = 3). Six tumors were aneuploid (DI, 1.33 +/- 0.17; PI, 17.1 +/- 5.3). These were uniformly large when compared with the diploid tumors, which were more variable in size. All of the aneuploid tumors were associated with moderate to severe cerebral edema. Two partly psammomatous tumors with high PIs and foci of high cellularity suggesting recent growth were associated with severe edema. One of these exhibited brain invasion. These preliminary data indicate that FC may have a potential use in the clinical management of meningiomas.

Aged↗
PubMed1988

Magnetic resonance imaging of the craniovertebral junction in rheumatoid arthritis.

Conventional radiography and magnetic resonance imaging (MRI) of the craniovertebral junction were evaluated in 12 patients with longstanding rheumatoid arthritis (RA) and neck pain with or without other neurologic signs or symptoms of cervical myelopathy. MRI demonstrated abnormal soft tissue masses thought to represent pannus in 9 patients. Three patients showed cord or brainstem compression due to pannus or atlantoaxial subluxation. The 3 patients with MRI evidence of cord or brainstem compression had neurologic signs or symptoms of cervical myelopathy, and appropriate therapy was instituted based on these findings. This study indicates that MRI is able to detect abnormal soft tissue masses which probably represent pannus and their relationship to the spinal cord or brainstem, and confirms the utility of the procedure in the management of craniovertebral involvement in RA.

Adult↗
PubMed1987

Granuloma annulare: a rare occipital lesion in infants and children.

Subcutaneous granuloma annulare is a rare scalp lesion that occurs in infants and children. Occurrence in the occipital region, absence of bone involvement, slow growth, and foci of necrosis of collagen surrounded by palisading granulomatous inflammation are characteristic of this lesion. Although the cause remains unknown, it is not infectious and is more likely due to a defect in cell-mediated immunity. The prognosis after excision is excellent. Increased awareness that this peculiar granulomatous lesion can rarely occur in the soft tissue of the occipital region will help prevent confusion with neoplastic or infectious processes.

Granuloma↗
PubMed1987

Histologic diagnosis of Hirschsprung's disease. The value of concurrent hematoxylin and eosin and cholinesterase staining of rectal biopsies.

False positive and negative results can complicate the diagnosis of Hirschsprung's disease (HD) with the acetylcholinesterase (AChE) stain. To improve the diagnostic value of this test, the authors evaluated the concurrent hematoxylin and eosin (H and E) staining of extra sections after the AChE procedure. Flash-frozen (FF), cryostat-cut (CC) sections of rectal suction biopsies from 96 patients with constipation were evaluated by AChE together with H and E staining of additional unstained sections. In 13 of 15 cases of HD with a diagnostic (positive-A) AChE pattern, the H and E sections confirmed the diagnosis. In five cases with other AChE patterns, the H and E sections were instrumental when the diagnosis was made. Of the 76 non-HD subjects with positive-B (n = 8), equivocal (n = 6), and negative (n = 62) AChE patterns, the H and E sections eliminated the diagnosis in 62 (81%). Neuronal and nerve fiber morphologic characteristics were excellent. Rebiopsies were needed in 14 subjects (19%) when there was failure in finding neurons. Simplicity, quickness, and the high quality of the histologic preparations make this procedure a useful adjunct to the AChE stain.

Acetylcholinesterase↗
PubMed1986

Giant cell tumors of synovium (Pigmented villonodular synovitis) involving the vertebral column.

Giant cell tumors of synovium (pigmented villonodular synovitis) involving the vertebral column recently have been seen in two women: the third and fourth cases to be reported in the English-language literature. Unlike the previously reported cases, both these tumors grew outside the dura and produced symptoms of spinal cord compression. The first case involved lumbar vertebrae 5 and 6; the second, lumbar vertebrae 2 and 3. Even though initial resection of both tumors was incomplete, the patients improved postoperatively. One tumor was known to be unresectable at the time of surgery. In the other patient, a recurrence of symptoms required second and third resections 4 and 8 months after the first, respectively. Although synovial giant cell tumors rarely metastasize, the rate of local recurrence is high, especially if excision is incomplete. For this reason, close follow-up of patients with lesions in the spinal column is indicated. Increased physician awareness that synovial giant cell tumors can occur in the spine will help to ensure that these tumors are not misdiagnosed in this location.

Adult↗
PubMed1986

Chronic vermal herniation in a case of osteosarcoma of the occipital bone.

Upward projection of the cerebellar vermis through the tentorial hiatus is called upward vermal herniation (UVH). UVH is less common in clinical practice than uncal herniation. Even more uncommon is chronic vermal herniation and impaction in the tentorial hiatus. To illustrate this phenomenon, we present the clinical, radiological, and morphological features of vermal impaction in a patient with a postradiation osteosarcoma of the occipital bone. In spite of nearly total excision of the tumor pushing the cerebellum upward, his postoperative course was complicated by respiratory problems and an altered level of consciousness, finally resulting in death. His clinical status paralleled the computed tomographic (CT) demonstration of persistent obliteration of the supramesencephalic cistern. CT makes more reliable the detection and management of UVH, but a high index of suspicion is necessary for prevention of this complication.

Adult↗
PubMed1986

Encephalic microvascular abnormalities in hypertension. A light and X-ray microscopic study.

Brain and cervical spinal cord removed at autopsy from hypertensive humans have been subjected to 4 levels of microscopic study, 3 being first histochemically prepared so as to stain the arterial and capillary system. Thick (100 microns) sections for light microscopy and thicker (500-1000 microns) for x-ray microscopy facilitate the study of long, complex anatomic units. Arterial and arteriolar microaneurysms have not been found. In addition to the usual age related vascular changes in normal people we have found: moniliform capillary dilatations, focal segments of arteriolar narrowing, état pre-criblé, and lacunar infarcts. Few changes have been encountered in the corpus callosum. While the segmental arteriolar narrowing occurs in the cortex as well as deep white matter, the effects of resultant poor perfusion might be expected to be more profound in the deep white matter.

Animals↗
PubMed1985

Pathobiologic study of pituitary tumors: report of 62 cases with a review of the recent literature.

Advances in radioimmunoassay procedures, immunocytochemistry, neuroradiologic imaging, and the surgical and medical treatment of pituitary adenomas have led to reappraisal of their classification as well as refinements in the diagnostic approaches used by pathologists. Sixty-two pituitary adenomas are described, and recent advances in this field are reviewed. Most of the patients were adults, but one of the adrenocorticotropic hormone (ACTH)-producing adenomas occurred in an 11-month-old infant. Endocrine-inactive tumors (43.5 per cent) were less common than hormone-producing tumors (56.5 per cent). Local invasion was most common in the former group, followed by ACTH-producing and other hormone-producing tumors. Ultrastructural features correlated with hormonal levels in the growth hormone(GH)-secreting tumors but not in the prolactin(LTH)- or ACTH-producing tumors. The formation of 7-nm filaments in the cytoplasm of tumor cells, corresponding to Crooke's hyaline change on light microscopy, was characteristic of ACTH-producing tumors. Ultrastructural changes in the ACTH granules suggested that the filaments may be derived from the feedback action of cortisol. Prior to surgery, a Rathke's cleft cyst and a chordoma were mistaken for endocrine-inactive pituitary adenomas. In two additional cases ectopic ACTH-producing tumors of lung clinically mimicked pituitary adenoma. Conversely, one pituitary adenoma mimicked sphenoid wing meningioma. Clinical, hormonal, and radiologic data and immunocytochemical and electron microscopic studies are needed for accurate pathologic interpretation and classification of pituitary adenomas.

Adenoma↗
PubMed1984

ACTH-producing pituitary adenoma in an infant with cysts of the kidneys and lungs.

The light microscopical, electron microscopical and immunohistological features of a rare ACTH-producing chromophobe adenoma of the pituitary gland in an 11-month-old infant are presented. An unusual histological feature was the presence of numerous follicles. These follicles may develop secondary to necrosis of individual tumour cells. There is only one previous report in the literature of a pituitary adenoma occurring in infancy and that tumour also produced ACTH and showed a follicular histological pattern. It is of interest that our patient also had a combination of medullary cysts of the kidneys and congenital peripheral cysts of the lungs. The association of cysts in lungs with cysts in kidneys also has been reported only once previously. We conclude that the occurrence of cysts in kidneys and lungs and a pituitary tumour in infancy represents a bizarre coincidence although an unknown common embryonic insult to these organs cannot be ruled out.

Adenoma↗
PubMed1983

Pathologic alterations in the brain and liver in hyperpipecolic acidemia.

Pipecolic acid is a cyclic secondary imino acid produced in the metabolism of lysine. The metabolic role and fate of pipecolic acid in the human central nervous system are largely unknown. The biochemical defect in two brothers, both less than two years of age, with minor dysmorphic features, progressive neurological dysfunction, and hepatomegaly was identified as hyperpipecolatemia. At autopsy, the older brother's brain weight was increased, with bilateral pallor of the putamen. Distinctive changes included accumulation of 1-1.5 micrometer periodic acid-Schiff (PAS) positive, diastase-resistant, Alcian blue-negative, non-lipid, non-fluorescent granules in astrocytes, satellite cells, and perivascular foot processes. Both light and electron microscopy showed total absence of these granules in neurons. In the older sibling, the liver showed micronodular cirrhosis with distinctive intrahepatocytic accumulation of 0.2-1 micrometer membrane-bound material of low electron density. Pericellular fibrosis and similar cytoplasmic inclusions were present in the liver biopsy from his brother. The distinctive astrocytic storage phenomenon and the liver changes are compared to the findings in Zellweger's syndrome and lysinuric protein intolerance, which are also associated with altered pipecolate metabolism.

Brain↗
PubMed1983

Familial brain tumors: studies of two families and review of recent literature.

We studied two families in each of which three or more individuals were affected by brain tumors. In the first family, which had no evidence of neurofibromatosis or tuberous sclerosis, a man, his sister, and her son developed histologically proven gliomas; the man's great uncle was historically reported to have died from a brain tumor, but the exact nature of the tumor was not known. In this family two of the tumors were low grade astrocytomas of the cerebrum, whereas the third was a mixed glioma of the cerebellum. Karyotypic analysis of this tumor showed no marker chromosomes. A second family had a history of an unusual concentration of brain tumors. In one patient the tumor was a histologically verified glioma. Four other patients had historically reported brain tumors, the descriptions of which suggested gliomas. Both families showed involvement of individuals in adjacent generations, although in both instances there were skipped generations. Twins, siblings, or parents and children are the kindred groups affected in most other reported families with multiple brain tumors. The mode of inheritance of brain tumors in these two families and recent literature on the conditions associated with familial brain tumors are discussed.

Adult↗