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Biomedical subjects

Srinivas Rao

Publications and source records attributed to Srinivas Rao.

5 recordsLinked to original sources
PubMed2003

Segmental jejunal lipomatosis--a rare cause of intestinal obstruction.

A rare case of a segmental small intestinal (jejunal) lipomatosis is described. A 33-year-old male was admitted with a clinical diagnosis of an acute intestinal obstruction. A plain erect abdominal x-ray showed multiple air-fluid levels. On an exploratory laparotomy, a jejunojejunal intussusception was found secondary to a segmental submucosal lipomatosis. This was treated by a segmental resection and anastomosis, which resulted in a complete cure. Here we present this case with a review of the relevant literature.

Adult↗
PubMed2003

Febrile-range hyperthermia augments pulmonary neutrophil recruitment and amplifies pulmonary oxygen toxicity.

Febrile-range hyperthermia (FRH) improves survival in experimental infections by accelerating pathogen clearance, but may also increase collateral tissue injury. We hypothesized that FRH would worsen the outcome of inflammation stimulated by a non-replicating agonist and tested this hypothesis in a murine model of pulmonary oxygen toxicity. Using a conscious, temperature-controlled mouse model, we showed that maintaining a core temperature at FRH (39 degrees C to 40 degrees C) rather than at euthermic levels (36.5 degrees C to 37 degrees C) during hyperoxia exposure accelerated lethal pulmonary vascular endothelial injury, reduced the inspired oxygen threshold for lethality, induced expression of granulocyte-colony stimulating factor, and expanded the circulating neutrophil pool. In these same mice, FRH augmented pulmonary expression of the ELR(+) CXC chemokines, KC and LPS-induced CXC chemokine, enhanced recruitment of neutrophils, and changed the histological pattern of lung injury to a neutrophilic interstitial pneumonitis. Immunoblockade of CXC receptor-2 abrogated neutrophil recruitment, reduced pulmonary vascular injury, and delayed death. These combined data demonstrate that FRH may enlist distinct mediators and effector cells to profoundly shift the host response to a defined injurious stimulus, in part by augmenting delivery of neutrophils to sites of inflammation, such as may occur in infections. In certain conditions, such as in the hyperoxic lung, this process may be deleterious.

3T3 Cells↗
PubMed2002

Structural and functional alterations of the gastrointestinal tract following radiation-induced injury in the rhesus monkey.

A severe and debilitating diarrhea is a dose-limiting toxic result for patients receiving abdominal radiation or chemotherapy. To correlate changes in intestinal structure and function, nonhuman primates were exposed to 9.5 Gy total abdominal x-irradiation. Diarrhea and weight loss were correlated with intestinal crypt and villus histology, in vivo assessed intestinal permeability, and ex vivo functional studies performed in Ussing chamber assays before and at 7, 14, and 35 days after irradiation. Peak gut structural damage occurred early and paralleled functional changes of the intestinal mucosa, including increased epithelial permeability (both in vivo and ex vivo), activation of secretory pathways, decreased nutrient absorption, diarrhea, and weight loss. Recovery of gut integrity and epithelial resistance began thereafter, in spite of incomplete histological recovery. Our integrated approach allowed a comprehensive study of the relationship between postirradiation tissue injury and changes in function over time in the gastrointestinal tract of the nonhuman primate.

Animals↗
PubMed2002

Characterization of a murine model of Ureaplasma urealyticum pneumonia.

Ureaplasma urealyticum respiratory tract colonization in preterm infants has been associated with a high incidence of pneumonia and the development of bronchopulmonary dysplasia. However, study of this human pathogen has been hampered by the absence of animal models. We have developed the first juvenile mouse model of Ureaplasma pneumonia and characterized the histopathology during the month following inoculation. C3H/HeN mice were inoculated intratracheally with a mouse-adapted clinical Ureaplasma isolate (biovar 2) or sham inoculated with 10B broth. Culture of lung homogenates and PCR of DNA from bronchoalveolar lavage fluid (BAL) confirmed the presence of Ureaplasma in 100% of inoculated animals at 1 day, 60% at 2 days, 50% at 3 days, and 25% at 7 and 14 days. Ureaplasma was undetectable 28 days postinoculation. There were marked changes in BAL and interstitial-cell composition with increased number of polymorphonuclear leukocytes 1 to 2 days and 14 days postinoculation and macrophages at 2 and 14 days postinoculation. The Ureaplasma infection caused a persistent focal loss of airway ciliated epithelium and a mild increase in interstitial cellularity. There were no differences in BAL protein concentration during the first 28 days, suggesting that pulmonary vascular endothelial barrier integrity remained intact. Comparison of BAL cytokine and chemokine concentrations revealed low levels of tumor necrosis factor alpha (TNF-alpha) at 3 days and monocyte chemoattractant protein 1 at 7 days in Ureaplasma-infected mice but a trend toward increased TNF-alpha at 14 days and increased granulocyte-macrophage colony-stimulating factor and interleukin-10 at 28 days. These data suggest that Ureaplasma alone may cause limited inflammation and minimal tissue injury in the early phase of infection but may promote a mild chronic inflammatory response in the later phase of infection (days 14 to 28), similar to the process that occurs in human newborns.

Animals↗