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Biomedical subjects

R Murthy

Publications and source records attributed to R Murthy.

8 recordsLinked to original sources
PubMed1992

Polyamine levels, ornithine decarboxylase (ODC) activity, and ODC-mRNA expression in normal and cancerous human colonocytes.

Ornithine decarboxylase (ODC) and polyamines (putrescine, spermidine, and spermine) are crucial for cell proliferation. Recently, elevated ODC activity and polyamine levels have been suggested as biological markers for human colon cancer. In this study, we measured ODC activity and the levels of polyamines (putrescine, spermidine, spermine, and cadaverine) and acetyl-putrescine in human colonocytes isolated from cancerous areas compared to the adjacent normal colon tissue. In addition, ODC mRNA expression was compared between both groups. We found that colonocytes isolated from cancerous areas had significantly higher mean value of ODC activity, putrescine, spermidine, spermine, and cadaverine levels up to 1480%, 470%, 260%, 380%, and 510% respectively compared to colonocytes isolated from the adjacent normal colonic mucosa. No difference was found in acetyl-putrescine levels between cancerous and normal colonocytes. Steady-state levels of ODC mRNA were slightly elevated in cancerous colonocytes relative to normal colonocytes in two of three paired samples. However, the increase in ODC mRNA levels is not sufficient to account for the increase in ODC activity suggesting that colonocyte ODC activity is regulated post-transcriptionally.

Adult↗
PubMed1991

Isolation of wound-specific cDNA clones from a cDNA library prepared with mRNAs of alkali-burned rabbit corneas.

Alkali burn is one of the most severe corneal injuries. In order to gain a better understanding of the healing of alkali-burned corneas, it is necessary to identify and characterize proteins that are specifically synthesized by the injured corneal tissues. In this study, we developed a useful procedure to identify and isolate cDNA clones that encode messenger ribonucleic acids (mRNAs) that are specific and/or abundant in alkali-burned rabbit corneas (ARCs), but absent in normal rabbit corneas (NRCs). At first, a cDNA library was prepared by cloning cDNA of mRNA isolated from ARCs into the lambda ORF-8 vector. A differential plaque hybridization was used to screen 2.5 x 10(4) plaque-forming units (pfu) from an ARC cDNA library using 32P-labeled cDNAs prepared from mRNA of ARCs and NRCs. Thirty-seven cDNA clones of mRNAs specific for ARCs were identified and isolated in their pureform. The cDNA inserts of these lambda ORF-8 phages were subcloned into the pSM216 vector by in vivo recombination. The cDNA inserts then were characterized by restriction enzyme digestion, i.e., BamHI, HindIII, and EcoRI. The size of the cDNA inserts ranged from 210 to 5,000 base pairs. Using Northern blot hybridization of total RNA prepared from polymorphonuclear neutrophils, mononuclear leukocytes, alkali-burned corneas, and normal corneas, the cDNA clones were divided into three groups. Five cDNA clones encoded mRNA of corneal cells in ARCs. Twenty-four cDNA clones derived from mRNA of inflammatory cells were present in alkali-burned corneas, but Northern blot hybridization failed to identify mRNA of discrete sizes.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkalies↗
PubMed1990

Pseudoepitheliomatous hyperplasia and pyoderma gangrenosum after a brown recluse spider bite.

Brown recluse spider bites may result in extensive soft tissue injury, causing months of disability. We have described a patient who had a series of extensive surgical debridements after envenomation. Despite skin grafting, persistent cutaneous lesions and extensive satellitosis progressed to involve the entire lower extremity. A recent biopsy showed pseudoepitheliomatous hyperplasia and pyoderma gangrenosum complicating the original injury. Although the role of early surgical excision and newer forms of medical treatment including dapsone and antivenom are still in evolution, recent reports suggest that the majority of patients will respond to medical therapy and may not require any surgical intervention.

Animals↗
PubMed1979

Pericardial effusions in sarcoidosis.

A case of sarcoid pericarditis is presented. The associated pericardial effusion was a transudate with a low complement level. Investigating the prevalence of pericardial effusions in sarcoid by echocardiography, we found small effusions in 19 percent of 48 consecutive patients with sarcoid. Additionally, ten previously reported cases of symptomatic parietal pericardial sarcoid are reviewed.

Female↗
PubMed1975

Investigation of alveolar macrophages from rats exposed to coal dust.

Rats were exposed to the inhalation of coal dust from either Utah (low prevalence coalworkers' pneumoconiosis (CWP)) or Pennsylvania (high prevalence CWP). Rats were sacrificed, the lungs removed and lavaged to obtain free cells. The number of alveolar macrophages recovered from rats inhaling these two coal dusts (exposures up to 4 months) was not remarkably different from the number recovered from rats inhaling filtered room air. This is in contrast to results obtained after intratracheal intubation of the dust. The capacity of the lavaged cells to phagocytize and kill bacteria decreased after exposure to either dust. The activity of certain enzymes also decreased.

Acid Phosphatase↗