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Biomedical subjects

Jayaprakash Sreenarasimhaiah

Publications and source records attributed to Jayaprakash Sreenarasimhaiah.

10 recordsLinked to original sources
PubMed2005

Diagnosis and management of ischemic colitis.

The clinical presentation and outcome of ischemic colitis has a wide spectrum. Impaired perfusion of blood to the bowel from a variety of causes is the underlying pathophysiology. The presence of diarrhea, abdominal pain, and mild lower gastrointestinal bleeding should prompt consideration of ischemic colitis as a cause. Although many laboratory tests and radiographic images may suggest the diagnosis, endoscopic visualization of colonic mucosa with histologic analysis of biopsies is the gold standard for identification of colonic ischemia. Most cases are transient and resolve without any complications. Medical therapy for chronic ischemia has been anecdotally proven but not carefully studied. Complications of ischemic colitis can include bowel perforation, peritonitis, persistent bleeding, protein-losing colopathy, and symptomatic intestinal strictures. Thus, surgical resection of the affected segment should be considered early to minimize adverse outcomes. This review describes the etiology, pathophysiology, clinical features, diagnostic approach, and management of ischemic colitis.

Clinical Trials as Topic↗
PubMed2005

Chronic mesenteric ischemia.

Chronic mesenteric ischemia is an unusual but important cause of abdominal pain. Although this condition accounts for only 5% of all intestinal ischemic events, it can have significant clinical consequences. Among its many causes, atherosclerotic occlusion or severe stenosis is the most common. This disorder has an indolent course that results in extensive collateral vascular formation. Thus, symptoms occur when at least two of the three main splanchnic vessels are affected. Intestinal angina, weight loss, and sitophobia are common clinical features. Diagnosis can often be made by noninvasive methods such as computerised axial tomographic angiography, magnetic resonance angiography, and duplex ultrasonography as well as by invasive catheter angiography. Therapy of chronic mesenteric ischemia depends on the extent and location of vascular disease. Alternatives to traditional surgical bypass are becoming more common including embolectomy, thrombolysis, and percutaneous angioplasty with vascular stenting. Early intervention is vital as the natural course of this illness can be debilitating. Furthermore, this has potential to develop into life-threatening acute mesenteric ischemia with subsequent bowel infarction and death. Long-term studies have shown that the risk of developing symptoms from asymptomatic but significant mesenteric vascular disease is 86% with overall 40% mortality rate. The recognition and management of this unusual but important cause of abdominal pain is discussed in detail in this review.

Abdominal Pain↗
PubMed2005

The emerging role of endoscopic ultrasonography in cancer staging.

The management of solid organ cancers relies on accurate staging. Once distal metastasis has been excluded by conventional radiographic methods, local staging of the tumor and its nodal involvement is essential to determine the most optimal therapeutic approach. Many radiographic imaging modalities are unable to determine subtle tumor involvement. However, the emergence of endoscopic ultrasonography (EUS) has given promise to improved staging with its unique ability to examine tumors from within the gastrointestinal lumen with extremely close proximity. An additional advantage is the ability to perform fine-needle aspiration (FNA) biopsy to confirm or exclude tumor involvement. Many studies have shown superior accuracy in staging with EUS and EUS-FNA for tumors of the esophagus, stomach, pancreas, rectum, and mediastinum, including lung cancer. This review illustrates the principles of EUS and its role in staging of a variety of cancers and particularly its role alongside other imaging modalities.

Biopsy, Fine-Needle↗
PubMed2004

Prevention or Surgical Treatment of Gallstones in Patients Undergoing Gastric Bypass Surgery for Obesity.

It is well known that obesity is a risk for gallstone formation and biliary sludge. Additionally, it has been clearly shown that rapid weight loss following bariatric surgery is a risk factor for cholesterol cholelithiasis. Multiple serious complications from gallstones such as cholecystitis, cholangitis, gallstone pancreatitis, and cholecystenteric fistulae may occur. Thus, it is necessary to employ medical or surgical methods to prevent or treat gallstones in this group. Therapy should be individualized. Although there is a high incidence of gallstones in this group, only a minority of individuals will develop symptomatic disease. When used in patients who are compliant, ursodeoxycholic acid therapy can be effective to prevent gallstone formation during rapid weight loss. The cost effectiveness of routine ursodeoxycholic acid therapy compared with the potential costs of complicated gallstone disease needs to be further investigated. Combined cholecystectomy with Roux-en-Y gastric bypass surgery is a safe and appropriate therapeutic option in those with preoperatively known gallstones, biliary sludge, and prior episodes of cholecystitis. However, routine cholecystectomy at the time of gastric bypass surgery is not warranted for all patients because of the increased time of operation and postoperative hospitalization, as well as all the potential complications after cholecystectomy. The approach of routine cholecystectomy in this setting subjects many patients to an unnecessary procedure because the majority will not develop symptoms or complications of gallstones. Furthermore, cholecystectomy is technically easier to perform after weight loss occurs.

Journal Article↗
PubMed2003

Lack of optimal T-cell reactivity against the hepatitis C virus is associated with the development of fibrosis/cirrhosis during chronic hepatitis.

Chronic hepatitis C virus (HCV) infection develops in 85% of exposed individuals and 20% develop cirrhosis. However, the pathogenesis of this process is not well-understood. The objective of this study was to determine whether HCV-reactive T cells play a role in the process of development of cirrhosis during chronic HCV infection. We analyzed 21 human leukocyte antigen (HLA)-A2 patients with chronic HCV infection (9 with histology of inflammation and 12 with histology of fibrosis/cirrhosis). The frequency of CD8(+) T cells reactive to 12 HCV-derived epitopes was determined by an interferon-gamma enzyme-linked immunospot (ELISPOT) assay. The frequency of CD4(+) Th1 and Th2 cells reactive to the HCV core antigen was determined by interferon-gamma and interleukin-5 ELISPOT assays, respectively. Patients with histology of inflammation showed a significantly higher CD8(+) T-cell response to five HCV-derived epitopes (YLLPRRGPRL [core], CINGVCWTV [NS3], LLCPAGHAV [NS3], ILAGYGAGV [NS4B], and GLQDCTMLV [NS5B]) as compared with patients with histology of fibrosis/cirrhosis. Also, patients with histology of inflammation showed a significantly higher CD4(+) Th1 response to the HCV core antigen as compared to patients with histology of fibrosis/cirrhosis. These results indicate that a lack of an optimal T-cell response to HCV is associated with the development of cirrhosis during chronic HCV infection.

Adult↗
PubMed2003

Concomitant augmentation of type 1 CD4+ and CD8+ T-cell responses during successful interferon-alpha and ribavirin treatment for chronic hepatitis C virus infection.

The combined interferon-alpha (IFN-alpha) and ribavirin (IFN-alpha/ribavirin) therapy for chronic hepatitis C virus (HCV) infection results in sustained viral eradication in 31%-64% of the patients. Previous studies have strongly suggested that HCV-specific T-cell responses maybe modulated during this therapy. The objective of this study was to further define the effect of IFN-alpha/ribavirin therapy on type 1 and type 2 HCV-specific CD4(+) and CD8(+) T-cell responses during IFN-alpha/ribavirin therapy. Toward this, serial CD8(+) T-cell responses to HCV-derived epitopes and CD4(+) T-cell responses to the HCV core antigen were analyzed in four patients before (baseline), during (at 24 weeks), and at the end (at 48 weeks) of IFN-alpha/ribavirin therapy. Therapy-induced viral clearance in three patients was associated with a significant augmentation of HCV-specific type 1 CD4(+) and CD8(+) T-cell responses. In contrast, in a patient who did not respond to therapy, a significant HCV-specific CD4(+) Th2 cell reactivity was observed accompanied by a lack of augmentation of the HCV-specific CD8(+) T-cell reactivity. These results indicate that enhancement of HCV-specific CD4(+) and CD8(+) T-cell responses is an important factor in determining the response to the IFN-alpha/ribavirin therapy and the outcome of the HCV infection.

Antiviral Agents↗