background: acute upper gi bleeding (ugib) is a common medical emergency situation. in the past years, important changes have taken place that might have influenced the incidence, etiology, and outcome for patients with acute ugib. the aim of this study was to determine current time trends in the incidence, management, and prognosis of patients with ugib in 14 years period in a region in center...

We formulate a control problem for GI/GI/N+GI queue, whose objective is to trade off the long-run average operational costs with server utilization costs. To solve problem, we consider an asymptotic regime in which arrival rate and number of servers grow large. The solution associated fluid motivates that non-idling service disciplines are not general optimal, unless some arrivals turned away. ...

background: it is thought that the transmission of hepatitis b virus (hbv) through the endoscopic procedures is a very rare event. the aim of this study is to evaluate the effect of the standard disinfection procedure of the endoscopes and accessories versus conventional disinfection in the transmission of hbv. materials and methods: a prospective survey, comprising 520 consecutive upper gastro...

background: colonoscopy is used for both diagnostic as well as therapeutic purposes in patients with lower gi symptoms. the aim of this study was to assess the clinical manifestations and to determine the colonoscopic findings of children with lower gi symptoms attending a pediatric hospital in tehran. materials and methods: during a 5-year period (1996-2001), all children less than 16 years of...