Biomedical subjects

R K Moorthy

Publications and source records attributed to R K Moorthy.

5 recordsLinked to original sources

PubMed2004

Uninstrumented ventral surgery for subaxial cervical spine tuberculosis: clinical and radiological outcome.

The clinical and radiological outcomes in 14 patients with subaxial cervical spine tuberculosis following uninstrumented anterior decompression surgery and medical treatment were retrospectively reviewed. All the patients underwent an anterior decompression with bone graft followed by immediate mobilization or a period of bed rest for 4 to 6 weeks. The clinical status and whole spine curvature of the cervical spine were assessed preoperatively and at follow up. There was an improvement in the Nurick's grade from a preoperative mean of 2.4 (range 0 - 5) to 1.2 (range 0 - 4) at follow up (p = 0.004). The whole spine curvature showed an improvement in 5 patients, was maintained in 6 patients and showed a kyphotic change in 1 of the 12 patients at follow up. There was evidence of good bony fusion in 12 of the 14 patients for whom data were available at follow up. Anterior decompression with autologous iliac bone graft led to a good clinical and radiological outcome in patients with subaxial cervical spine tuberculosis.

Adolescent↗

PubMed2003

Isolated ring-enhancing lesion of the brainstem in a patient with cyanotic heart disease: role of stereotactic intervention.

A 23-year-old man with cyanotic heart disease, presented with a ring-enhancing mass in the brainstem. Stereotactic intervention for this clinically and radiologically diagnosed pyogenic abscess, revealed a tuberculoma. Antituberculous therapy led to complete recovery. Stereotactic intervention is an ideal management strategy in patients with cyanotic heart disease and an isolated ring-enhancing mass in the brainstem.

Adult↗

PubMed2002

Skull base chondroblastoma: a case report.

Chondroblastoma is a rare tumor of the skull. Temporal bone is the commonest site of involvement in the skull. We present a thirty one year old man who presented with painless swelling over the left temporal bone, which was near totally excised after preoperative embolization. Management of this unusual tumor and its complications are discussed.

Adult↗

PubMed1993

All three domains of the Epstein-Barr virus-encoded latent membrane protein LMP-1 are required for transformation of rat-1 fibroblasts.

LMP-1, the Epstein-Barr virus latent membrane protein 1, is the only protein encoded by the virus that has been shown to have the properties of a transforming oncogene in rodent fibroblasts such as Rat-1 cells. LMP-1 is phosphorylated and proteolytically cleaved in Rat-1 cells in a manner similar to that seen in human lymphocytes. In this study, we demonstrate that all three major domains of LMP-1 (N-terminal, transmembrane, and C-terminal domains) are required for the ability to transform Rat-1 cells in culture, as assayed by loss of contact inhibition. This study is the first demonstration of a functional role for the C-terminal domain of LMP-1. Our analysis suggests that there are at least three distinct regions of the C terminus involved in signalling. Amino acids 306 to 334, which generate a toxic signal in the absence of amino acids 334 to 364, and the last 23 amino acids, 364 to 386, are essential for transformation. Biochemical analysis of the LMP-1 mutants with the three domains deleted indicate that the mutant N-terminal with the domain deleted is phosphorylated normally but is inefficiently cleaved compared with the wild-type LMP-1. The mutant with the transmembrane domain deleted is also phosphorylated but is not cleaved, showing that phosphorylation of LMP-1 does not require membrane association. The nontransforming mutant with the C-terminal domain deleted that lacks the last 23 amino acids is phosphorylated and cleaved. Therefore, these processing events alone are insufficient to generate a transforming signal.

Amino Acid Sequence↗

PubMed1993

Biochemical, genetic, and functional analyses of the phosphorylation sites on the Epstein-Barr virus-encoded oncogenic latent membrane protein LMP-1.

LMP-1 is the only Epstein-Barr virus-encoded latent protein known to have the properties of a transforming oncogene in rodent fibroblasts and the only latent protein, besides EBNA-1, detected in nasopharyngeal carcinoma and Hodgkin's lymphoma biopsies. LMP-1 is characterized by serine/threonine phosphorylation and rapid turnover (half-life, 2 to 3 h) due to specific proteolytic cleavage, which causes release of a phosphorylated C-terminal fragment (p25) into the cytoplasm. We used biochemical, functional, and mutational analyses to identify sites of phosphorylation. All of the phosphorylation sites detected lie in the C-terminal domain. In particular, we identified S-313 and T-324 as functionally important sites. Prevention of phosphorylation at S-313, by altering it to a glycine, prevented detectable phosphorylation of both LMP-1 and p25, indicating that it is a major site on both forms of the molecule. However, lack of detectable phosphorylation had no effect on p25 cleavage or on the ability of LMP-1 to transform Rat-1 fibroblasts. Alteration of S-313 to an aspartate resulted in a form of LMP-1 that was toxic to Rat-1 cells. Alteration of T-324 to a glycine residue had no detectable effect on the ability of LMP-1 to become serine phosphorylated or transform Rat-1 cells. Alteration of T-324 to a glutamate, however, inhibited all detectable phosphorylation and resulted in a form of LMP-1 that was unable to transform Rat-1 fibroblasts. These results are discussed in the context of a model in which LMP-1 function is modulated by phosphorylation and dephosphorylation at S-313 and T-324.

Amino Acid Sequence↗