Biomedical subjects

V Challa

Publications and source records attributed to V Challa.

7 recordsLinked to original sources

PubMed1999

Innervation density of the base of the palm.

Cutaneous nerves of the palm were localized and quantitated by longitudinal axis, proximity to the distal palmar crease, and tissue layer to identify an incision that would avoid injury to the palmar branches of cutaneous nerves. Cadaveric palms (n = 10) harvested en bloc were fixed at physiologic tension and prepared using the celloidin method and hematoxylin-eosin staining. The cutaneous nerves of the palm were counted and classified by their size and location within each tissue layer and longitudinal axis as well as by proximal, middle, and distal locations within each axis. The mean number of large nerves identified within regions of the palm differed by tissue layer and longitudinal axis but not by longitudinal location within axes. The long/ring finger web space was characterized by the lowest innervation density; the index/long finger web space and ring finger axis were characterized by the greatest innervation density. An incision in the long/ring finger web space 2 cm proximal to Kaplan's cardinal line should result in injury to fewer nerves and reduce the incidence of painful neuromas during open carpal tunnel release.

Dissection↗

PubMed1994

Autologous denatured muscle as a nerve graft.

This study examined the use of freeze-thawed muscle as a nerve graft material in Sprague-Dawley rats. In Group 1 (n = 4), the sciatic nerve was isolated and the incision immediately closed. In Group 2 (n = 4), a 5-mm segment of the nerve was removed and immediately replaced. In Group 3 (n = 50), a 5-mm segment of nerve was removed and muscle (2 x 2 x 5 mm, harvested from the gluteus, frozen in liquid nitrogen, and thawed in sterile water) was sutured in place. The short 5-mm segment of muscle provided an ideal situation for regeneration of myelinated nerve. Sciatic functional indices were comparable in all groups after 8 weeks and at 1 year. Histologic analysis showed comparable nerve regeneration in Groups 2 and 3 at 4 months. Group 3 grafts exhibited new axonal growth distal to the repaired gap at 4 weeks; myelinated fibers were present at 10 weeks. At 1 year, Group 3 nerves had almost the same axon count as contralateral nerves. However, myelin-sheath regeneration in the 5-mm muscle graft was incomplete, at 81 percent of normal, at 1 year.

Animals↗

PubMed1991

Angiotropic intravascular large-cell lymphoma (malignant angioendotheliomatosis): report of a case and review of the literature.

We present a case of angiotropic large-cell lymphoma and review the literature in order to define the neurologic features of this rare disorder. This is the first report of gadolinium-DTPA imaging in angiotropic large-cell lymphoma that demonstrates infarcts of multiple ages, as well as striking meningeal enhancement. Angiotropic large-cell lymphoma should be suspected in patients with clinical evidence of small and large cerebral vessel disease and diagnosis requires skin, liver, renal, meningeal, or brain biopsy. Single modality treatment, using either radiation therapy or steroids, has been ineffective, and new findings of a lymphomatous origin of this neoplasm suggest that combination chemotherapy may be indicated.

Brain Neoplasms↗

PubMed1990

Immunohistochemical localization of heat shock protein-70 in normal-appearing and atherosclerotic specimens of human arteries.

Heat shock proteins (HSPs) are synthesized by cells under metabolic stress and are known to enhance a cell's ability to survive life-threatening stress. The authors have begun to examine HSPs in the context of human atherosclerosis. This study demonstrated immunohistochemically the presence of HSP-70 in human and rabbit arteries, and its distribution in relation to necrosis and lipid accumulation, as well as vascular smooth muscle cells and macrophages, in human atherosclerotic plaques. Advanced lesions from 10 human carotid endarterectomy specimens were compared with 11 human aortic specimens from autopsy and 8 rabbit aortas. The immunostaining procedure used a mouse monoclonal antibody specific for the inducible form of HSP-70. Normal rabbit aortas were tested for changes in HSP-70 up to 24 hours after removal, and were used as controls for the human aortas. Representative plaques were examined for lipid content by osmium staining, and for smooth muscle cell and macrophage components using cell-specific monoclonal antibodies followed by immunostaining. The results indicated that HSP-70 was present in human and rabbit arteries and remained unchanged in distribution or concentration up to 15 hours after death. HSP-70 was present weakly throughout the media of normal-appearing arterial specimens. In contrast, HSP-70 was concentrated in the central portions of more thickened atheromas around sites of necrosis and lipid accumulation. Macrophages were coincident with these areas and were observed to be lipid-loaded. In contrast, patches of smooth muscle cells were observed in very complicated plaques, but without consistent association with necrosis or increased HSP-70; plaque smooth muscle cells also were observed to contain lipid. Large, relatively avascular and collagenous areas of plaque also were occasionally positive for HSP-70 staining. The results support the hypothesis that elevated HSPs indicate which plaque cells, particularly macrophages, are more stressed in the depth of atheroma, especially in association with necrosis, and should prompt further investigation of the significance of HSP accumulation to the evolution of atherosclerotic plaques.

Arteries↗

PubMed1982

Hypertrophic neuropathy with spinal cord compression.

The case of a 40-year-old patient with Dejerine-Sottas disease, who developed spinal cord compression from hypertrophic nerve roots, is presented. Six previously reported cases are reviewed. We discuss the characteristic myelographic changes seen in Dejerine-Sottas disease.

Adult↗

PubMed1978

Isolated histiocytosis X of the hypothalamus. Case report.

Failure to consider histiocytosis X in the differential diagnosis of hypothalamic masses may lead to inappropriate empirical radiotherapy. This report concerns a case of histiocytosis X of the hypothalamus, unassociated with systemic histiocytic lesions, in which early biopsy allowed specific therapy with subsequent total regression of the lesion.

Brain Diseases↗

PubMed1977

Extracranial metastases of glioblastoma multiforme confirmed by electron microscopy.

A case of glioblastoma multiforme which metastasized to the pleura and the lymph nodes of the neck is described. The metastases were detected during the life of the patient. The glial nature of the metastases was confirmed by electronmicriscopic demonstration of typical 90-100 angstrom wide glial fibrils occupying the tumor cell cytoplasm. Electronmicroscopy is recommended to prove the astrocytic nature of a metastatic glioblastoma multiforme. A review of the literature of histologically documented extracranial metastases of glioblastoma multiforme reveals an increase in frequency in recent years. Increased efforts at detection and documentation or an increase in occurrence caused by new methods of treatment are the two possible explanations for this trend.

Brain Neoplasms↗