Comparing reconstruction with ileocecal graft to jejunal interposition pouch after total gastrectomy in rats.

After total gastrectomy, the ileocecal graft may act as a reservoir and protect against reflux but give rise to transposition of the ileum and cause possible changes in bile acid metabolism and nutrition. This study compared the ileocecal graft and jejunal pouch. Male Wistar rats weighing 265 +/- 22 g were submitted to sham operation (S), ileocecal interposition graft (IIG), and jejunal pouch interposition graft (JP) after total gastrectomy. Eight weeks later, the esophagus was examined for evidence of esophagitis. Nutritional biochemistry and weight profile were documented preoperatively and 8 weeks after surgery. The oral glucose tolerance test was performed. Thirty-three rats were operated on and 30 survived for 8 weeks. Esophagitis occurred in seven JP rats. Body weight was significantly higher in IIG than in JP rats (p < .05). Normal glucose tolerance to intragastric glucose load was observed in sham and operated rats. JP rats had a significant decrease in serum albumin, glucose, transferrin, hemoglobin, iron, folate, and calcium, compared to sham (p < .05). Cobalamine was significantly lower in IIG rats than in JP rats (p < .05). In the IIG and JP groups, serum/hepatic total bile acid did not differ significantly from preoperative and sham values. In conclusion, the IIG interposition graft in rats prevented esophagitis, preserved nutrition, and did not interfere with enterohepatic total bile acid circulation.     

Peripheral spin exchange nuclear spin resonance angiography: Studies of the effect of blood flow on contrast

Sequential two-dimensional (2-D) inflow MR-angiography (SDSMRA) utilizes the bloodflow-induced changes in the MR-signal for intraluminal vessel contrast. To assess the effect of the peripheral arterial flowpulse on the average intraluminal MR-signalintensity (MIMRSI) seven healthy subjects, mean age 31 +/- 4 years, were studied using color Doppler flow mapping and SDSMRA. In each subject the regional MIMRSI was measured in 21 vascular segments and correlated with the regional flowpulse in a simple regression model. MIMRSI ranged from 915 +/- 299 in the right profunda femoris to 1378 +/- 283 in the distal abdominal aorta: distally, the trifurcation it was, with the exception of the posterior tibial artery in three subjects (MIMRSI = 545 +/- 64), not measurable. The regional differences in the peripheral flowpulse were without statistically measurable effect on MIMRSI. MIMRSI was best correlated to the systolic forward flow in 14, to the backward flow in 3, and to the mean forward flow in 1 vascular segment, respectively. The mean correlation coefficient (r) was 0.56, ranging from r = 0.11 in the right popliteal artery to r = 0.93 in the right superficial femoral artery. In the distal abdominal aorta no positive correlation between the blood flow and MIMRSI was determined. The regional differences in the peripheral arterial flow-pulse have no significant effect on MIMRSI in healthy men. MIMRSI correlates best with the systolic forward flow. However, on the average, 44% of the MIMRSI appear to be related to flow-independent yet unidentified factors. Optimal design of SDSMRA pulse sequences will require a better characterization of flow-dependent and flow-independent MIMRSI parameter.     

Phosphatase activity on the cell wall of Fonsecaea pedrosoi.

The activity of a phosphatase was characterized in intact mycelial forms of Fonsecaea pedrosoi, a pathogenic fungus that causes chromoblastomycosis. At pH 5.5, this fungus hydrolyzed p-nitrophenylphosphate (p-NPP) to p-nitrophenol (p-NP) at a rate of 12.78 +/- 0.53 nmol p-NP per h per mg hyphal dry weight. The values of Vmax and apparent Km for p-NPP hydrolyses were measured as 17.89 +/- 0.92 nmol p-NP per h per mg hyphal dry weight and 1.57 +/- 0.26 mmol/l, respectively. This activity was inhibited at increased pH, a finding compatible with an acid phosphatase. The enzymatic activity was strongly inhibited by classical inhibitors of acid phosphatases such as sodium orthovanadate (Ki = 4.23 micromol/l), sodium molybdate (Ki = 7.53 micromol/l) and sodium fluoride (Ki = 126.78 micromol/l) in a dose-dependent manner. Levamizole (1 mmol/l) and sodium tartrate (10 mmol/l), had no effect on the enzyme activity. Cytochemical localization of the acid phosphatase showed electrondense cerium phosphate deposits on the cell wall, as visualized by transmission electron microscopy. Phosphatase activity in F. pedrosoi seems to be associated with parasitism, as sclerotic cells, which are the fungal forms mainly detected in chromoblastomycosis lesions, showed much higher activities than conidia and mycelia did. A strain of F. pedrosoi recently isolated from a human case of chromoblastomycosis also showed increased enzyme activity, suggesting that the expression of surface phosphatases may be stimulated by interaction with the host.