Acute lung injury in a rat model of intestinal ischemia-reperfusion: the potential time depended role of phospholipases A(2)

BACKGROUND: A pivotal role of phospholipase A(2) (PLA(2)) and platelet-activating factor-acetylhydrolase (PAF-AcH) as enzymes involved in lung inflammation has recently been suggested. The objective of this study was to elucidate the role and the time dependence of PLA(2) and PAF-AcH fluctuations in the lung relative to the evolution of intestinal ischemia-reperfusion (IIR). MATERIALS AND METHODS: Rats were randomly allocated to five groups of IIR induced by occlusion of the superior mesenteric artery for 45 min followed by 1 min, 2, 4, and 8 h of reperfusion (expGroups) and five corresponding sham groups (sGroups). Bronchoalveolar lavage fluid was obtained from the right lung and its biochemical (protein, PLA(2), PAF-AcH) and cytological characteristics were determined. Plasma malonyldialdehyde was measured as a marker of lipid peroxidation. The 4 and 8 h reperfusion expGroups had significantly (P < 0.05) elevated alveolar-arterial O(2) gradient values compared with the corresponding controls. Total protein, PLA(2) and PAF-AcH levels significantly (P < 0.05) increased in expGroups compared with the corresponding shams after 4 h of reperfusion. Total bronchoalveolar lavage fluid cells and plasma malonyldialdehyde were significantly (P < 0.05) elevated in expGroups compared with the sGroups after 2 h of reperfusion. CONCLUSIONS: PLA(2) could act synergistically or parallel with the reactive oxygen species produced during IIR, resulting in the induction or even in the exacerbation of the inflammatory reaction in acute respiratory distress syndrome. PAF-AcH could play an anti-inflammatory role by reducing the concentration of PAF.     

SAFETY,EFFECTIVENESS AND COST EFFICACY OF DIAGNOSTIC ELECTROPHYSIOLOGY AND RADIOFREQUENCY ABLATION IN A DISTRICT GENERAL HOSPITAL

Electrophysiological studies (EPS) are now being performed in district general hospitals (DGH) in the UK. In order to audit our results, a prospective database was established for all patients undergoing EPS and radiofrequency (RF) ablation at Eastbourne District General Hospital, East Sussex. Between 1 January 1997 and 1 July 2000, 300 EPS procedures were performed, resulting in 155 RF ablations. The average RF ablation procedure time was 119.3 minutes with an average fluoroscopy time of 19.1 minutes. Cost per RF ablation procedure was £1166.79 excluding use of facilities, pacemaker devices, medical nursing and radiography staffing costs. The overall success rate for RF ablation was 93.6% with a major complication rate of 0.6%, a total complication rate of 3.9% and no associated mortality. We have shown that RF ablation can be performed safely, effectively and economically in a DGH setting with a high rate of success and a low complication rate.     

Stromal sarcoma arising on endometriosis. A clinicopathological and immunohistochemical study of 4 cases

The development of stromal sarcomas on the foci of endometriosis is extremely rare and the differential diagnosis from other tumors of myogenic, vascular, hemopoietic or epithelial origin may present great diagnostic difficulties. We investigated the clinicopathological and immunohistochemical characteristics of 4 cases of endometrial stromal sarcoma that developed on endometriotic foci of the uterus, vagina and omentum. Thye were classed as high grade (1/4) or low grade (3/4) malignant potential tumors, according to their mitotic activity. Immunohistochemically these tumors gave a positive reaction to vimentin, but were negative to desmin, smooth muscle actin, factor VIII, EMA and LCA. These characteristics permit their identification and a proper therapeutic approach.     

Splenic abscess. An old disease with new interest

BACKGROUND/AIMS: To study the demographics, signs and symptoms, causes, risk factors, imaging findings, bacteriologic profile, treatment and outcome of patients with splenic abscess. METHOD: The medical records of 17 patients with splenic abscess at two tertiary-care hospitals between 1989 and 1997 were retrospectively reviewed. The demographic data, physical and radiological findings, treatment, bacteriology reports and outcome of treatment were reviewed. RESULTS: The mean age of patients was 43 years (range 7-79 years). Fever and abdominal pain were the most prominent signs. Seven patients were immunocompromised, three had abscessed hydatic cysts, two were drug users and three suffered from splenic trauma, infarction, and endocarditis, respectively. No predisposing factor was identified in 2 patients. In all cases, CT demonstrated the splenic lesion(s). Staphylococcus species and Bacteriodes were the most common microbes, identified in the blood and abscess cultures. Thirteen patients underwent splenectomy, two medical therapy and two no therapy with respective survival rates of 92, 100 and 0%. CONCLUSION: Splenic abscess is a rare surgical entity encountered mostly in immunocompromised patients. CT scan is the gold standard for the definite diagnosis. Splenectomy is the treatment of choice, while medical therapy should be reserved for unusual pathogens provided that an effective antimicrobial agent is available.     

Evaluating patients with renal failure for renal artery stenosis with gadolinium-enhanced magnetic resonance angiography

The incidence and prevalence of end-stage renal disease (ESRD) continues to increase, especially in the elderly population. The role of renovascular disease in contributing to ESRD is still not well defined. The objective of this study was to determine the utility of gadolinium (Gd)-enhanced magnetic resonance angiography (MRA) in evaluating elderly patients with renal insufficiency for renal artery stenosis (RAS). A 7-month prospective study conducted in a tertiary referral center evaluated 40 consecutive patients with progressive renal insufficiency (18 men and 22 women; mean age, 70 +/- 5.6 [standard deviation] years) and high clinical suspicion for renovascular disease with Gd-enhanced MRA. Digital subtraction angiography (DSA) was obtained in only those patients with significant RAS detected by MRA. Twelve patients had significant RAS. Six of these patients had percutaneous transluminal renal angioplasty (PTRA), five patients had renal artery bypass surgery, and one patient had a stent placed after PTRA. Seventy-eight renal arteries were satisfactorily evaluated by MRA. Twenty-two renal arteries were evaluated by both MRA and DSA. Of the 12 significant stenoses detected by the MRA, 11 were confirmed by DSA and 1 was confirmed at the time of surgical revascularization. It is concluded that Gd-enhanced MRA is a useful test for the evaluation of RAS in patients with compromised renal function.     

Cystic tumors of the pancreas: preoperative imaging,diagnosis, and treatment

The objective of this retrospective study was to explore the accuracy of preoperative diagnostic methods and the efficacy of treatment for cystic pancreatic tumors. From 1989 to 1999, 18 patients underwent surgery for cystic tumor of the pancreas, classified as follows: one serous cystadenoma, eight mucinous cystadenomas, six mucinous cystadenocarcinomas, and three nonfunctioning islet cell tumors. Computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and fine needle aspiration were performed and subsequently reviewed retrospectively by two radiologists. Three patients underwent the Whipple procedure and 14 and 1 patients underwent distal and central pancreatectomy, respectively. CT showed cystic pancreatic tumors in all cases. One case was misdiagnosed as a pseudocyst. The diagnosis was accurate in 82%, 53%, 37%, and 60% of cases on CT, ERCP, and angiography, and in the cytologic analysis of the aspirated fluid, respectively. All operative procedures were performed without significant morbidity and there were no postoperative deaths. Preoperative diagnosis of cystic pancreatic tumours is imprecise. CT is the most reliable preoperative imaging method. Resection should be the treatment of choice for these lesions, except in cases of serous cystadenoma.     

Ischemic preconditioning versus intermittent vascular occlusion in liver resections performed under selective vascular exclusion: a prospective randomized study

BACKGROUND: The aim of this study was to compare ischemic preconditioning with the intermittent vascular occlusion technique in liver resections performed under inflow and outflow occlusion. METHODS: Fifty-four patients with resectable liver tumors assigned were randomly to undergo surgery with either ischemic preconditioning (IP group, n = 27) or with intermittent vascular occlusion (IVO group, n = 27). Both groups were compared regarding surgical parameters, aspartate transaminase levels, and apoptosis. RESULTS: For warm ischemic time less than 40 minutes, no significant difference was noticed between the 2 groups apart from caspase-3 activity, which was higher in the IVO group than in the IP group (17.2 +/- 3.4 vs. 10.3 +/- 5.2, P < .05). When warm ischemia exceeded 40 minutes, the IP group showed higher levels in blood aspartate transaminase levels on day 3 (442 +/- 178 IU/L vs. 305 +/- 104 IU/L, P < .05) and higher caspase-3 levels (26.5 +/- 5.7 count/high-power field [hpf] vs. 20.7 +/- 3.6 count/hpf, P < .05) and apoptotic activity (28.5 +/- 7.5 count/hpf vs. 20.2 +/- 4.1 count/hpf, P < .05), as compared with the IVO group. CONCLUSIONS: Although both techniques showed comparable efficacy for short ischemic times, intermittent vascular occlusion provided better cytoprotection when ischemia exceeded 40 minutes.