Biomedical subjects

Sundaram Challa

Publications and source records attributed to Sundaram Challa.

4 recordsLinked to original sources

PubMed2005

Comparative status of activated ERK1/2 and PARP cleavage in human gliomas.

Gliomas are the most common form of cerebral tumors. Understanding molecular features of glioma will eventually allow for targeted intervention and more promising approaches for treating gliomas. The present study is therefore carried out to check the levels of activated ERK1/2 with respect to phospho-tyrosine and cleavage of poly ADP-ribose polymerase (PARP). Recent experiments support that extracellular signal regulated kinase (ERK), a mitogen activated protein (MAP) kinase might have a critical role in cell proliferation. PARP is a DNA-repair enzyme activated by DNA strand breaks. Overactivation of PARP after cellular insult lead to cell death caused by rapid depletion of cellular ATP. Three glioblastoma multiforme (GBM) and two astrocytoma biopsies (core tumor) and peripheral tissues were analyzed for the expression of p-ERK1/2 and PARP. Results indicate higher p-ERK1/2 in GBM. Cleaved fragments of PARP (89 kDa) were found to be more in core tumor tissue samples as compared to peripheral tumor tissues of both astrocytoma and GBM.

Adult↗

PubMed2005

Congenital giant diverticulum of the left ventricle in an adult.

Congenital diverticulum of the left ventricle is a rare anomaly. Echocardiography, cardiac catheterization, and magnetic resonance imaging of the heart diagnosed a giant left ventricular diverticulum in a 20-year-old male with a history of dyspnea and palpitations. He underwent successful surgical correction of the left ventricular diverticulum.

Adult↗

PubMed2004

Fungal endocarditis: an autopsy study.

Between 1990 and 2002, 237 hearts were examined at autopsy, including 16 with infective endocarditis; 6 showed fungal endocarditis. The preceding pathology was chronic rheumatic heart disease in 2 patients, one of whom had undergone double valve replacement, 2 patients had been treated for acute lymphoblastic leukemia, and one had protein-energy malnutrition. The underlying cause was unknown in one case. The organisms isolated were Aspergillus in 3 patients, Zygomycota in 1, Candida in 1, and both Candida tropicalis and Aspergillus in 1 patient. Immunosuppressed states are a cause of fungal endocarditis in India, although chronic rheumatic heart disease is the preceding pathology in the majority of patients.

Adult↗

PubMed2004

Diagnosis of mitochondrial diseases: clinical and histological study of sixty patients with ragged red fibers.

BACKGROUND: Mitochondrial diseases are caused by mutations in mitochondrial or nuclear genes, or both and most patients do not present with easily recognizable disorders. The characteristic morphologic change in muscle biopsy, ragged-red fibers (RRFs) provides an important clue to the diagnosis. MATERIALS AND METHODS: Demographic data, presenting symptoms, neurological features, and investigative findings in 60 patients with ragged-red fibers (RRFs) on muscle biopsy, seen between January 1990 and December 2002, were analyzed. The authors applied the modified respiratory chain (RC) diagnostic criteria retrospectively to determine the number of cases fulfilling the diagnostic criteria of mitochondrial disease. RESULTS: The most common clinical syndrome associated with RRFs on muscle biopsy was progressive external ophthalmoplegia (PEO) with or without other signs, in 38 (63%) patients. Twenty-six patients (43%) had only external ophthalmoplegia, 5 (8%) patients presented with encephalomyopathy. Specific syndromes were the presenting feature in 8 (13%), Kearns-Sayre syndrome (KSS) in 4 and myoclonus epilepsy with ragged-red fibers (MERRF) in 4. Myopathy was the presenting feature in 5 (8%) and 4 presented with infantile myopathy. Of the 60 patients, 18 (30%) had proximal muscle weakness. Two patients with KSS and one patient with myopathy had complete heart block necessitating pace making. When the modified RC diagnostic criteria were applied, only 26 (43%) patients had one other major criterion in addition to RRFs for the diagnosis of mitochondrial diseases. The remaining 34 (57%) patients with RRFs on muscle biopsy had only some clinical features suggestive of RC disorder but did not fulfill the clinical criteria (of the modified diagnostic criteria) for the diagnosis of mitochondrial diseases. CONCLUSION: In patients with clinical features suggestive of RC disorder, demonstration of RRFs on muscle biopsy helps in confirming the diagnosis of mitochondrial disease in only a subgroup of patients.

Adolescent↗