Aberrant expression of beta-catenin and mutation of exon 3 of the beta-catenin gene in renal and urothelial carcinomas

The present study attempted to clarify the significance of aberrant expression of beta-catenin protein and mutation of exon 3 of the beta-catenin gene in renal and urothelial carcinogenesis. beta-Catenin expression was examined immunohistochemically and mutation of the beta-catenin gene was analyzed by polymerase chain reaction-single strand conformation polymorphism (SSCP) and direct sequencing. beta-Catenin immunoreactivity was observed at the cell membrane in all 30 renal cell carcinomas (RCC) examined, and no RCC showed a mobility-shifted SSCP band. Of 46 transitional cell carcinomas (TCC) examined, there was reduced expression of beta-catenin, as compared with its expression in non-cancerous transitional epithelium, in 22 cases (48%) and beta-catenin accumulation in the nucleus in five cases (11%). Of four renal pelvis TCC examined, point mutation of exon 3 of the beta-catenin gene at codon 45 resulting in amino acid substitution (Ser to Phe) was detected in one (25%). The incidence of reduced expression of beta-catenin correlated significantly with the growth pattern (superficial type vs invasive type) of TCC (P < 0.05). These data indicate that: (1) aberrant beta-catenin expression may be at least partly involved in urothelial carcinogenesis, but less significantly so in renal carcinogenesis, and (2) it may be associated with the progression of TCC showing invasive growth.     

Normal development of the gut-associated lymphoid tissue except Peyer's patch in MyD88-deficient mice

MyD88 is a key adaptor molecule for signalling via Toll-like receptors (TLRs) and the response to gut commensal microbes. To investigate the role of TLRs/MyD88 pathway in the development of the gut-associated lymphoid tissue (GALT), we examined the development of Peyer's patches (PPs) and cryptopatch (CP), and also one of effector compartment, intraepithelial lymphocyte (IEL) in MyD88-/-, TLR2-/- and TLR4-/- mice. In MyD88-/- mice, the organogenesis of PPs was not disturbed. However, PPs in 2-week-old MyD88-/- mice were significantly smaller than those in MyD88+/- mice. Also, in 2-week-old TLR4-/-, but not TLR2-/- mice, PPs did not develop rapidly. The development of PPs in MyD88-/- and TLR4-/- mice was completely recovered in 10 weeks. PP cells from MyD88-/- mice showed significant decrease in proliferation when stimulated with lipopolysaccharide. The development of CP and IEL was also normal in 10-week-old MyD88-/- mice. These results suggest that the TLRs/MyD88 pathway might be involved in the development of PPs only at early postnatal stage, and TLRs/MyD88-independent signalling is critically involved in the development of GALT in adult mice.     

Predictive value of an enzyme-linked immunosorbent assay (ELISA) for the serodiagnosis of strongyloidiasis

Strongyloides stercoralis is an opportunistic parasite of increasing importance in immunocompromised hosts. Current parasitologic methods for diagnosis are unsatisfactory, and the serologic screening of candidates for immunosuppression and other individuals at risk might prevent fatal disseminated infections. The predictive value of an enzyme-linked immunosorbent assay (ELISA) using S. stercoralis antigens has been evaluated on 268 infected patients, 571 noninfected controls, and 78 individuals with other parasitic infections. A positive test was accurate in predicting the presence of S. stercoralis in 97% of the cases, while a negative test was associated with absence of infection in 95% of the patients. Possible cross-reactivity occurred in some patients with Loa loa filariasis and Ascaris lumbricoides. The authors conclude that the ELISA is a reliable and cost-effective method for the screening of patients at risk, and its results can be used to determine the appropriateness of more in-depth parasitologic evaluation.     

Differentiation of fibrinolysis and fibrinogenolysis by analysis of FDP fragments]

We previously analysed the fragments of fibrin/fibrinogen degradation products (FDP) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) combined with immunoblotting. In this report, we studied the semi-quantitative analysis of fibrinolysis (degradation of cross-linked fibrin) and fibrinogenolysis (degradation of fibrinogen and/or unstable fibrin) of patients' samples by our method. In vitro study of FDP made it clear that an appearance of D fragment confirmed fibrinogenolysis and an appearance of DD fragment and/or high molecular weight fragments which have higher molecular weight than DY or X fragment confirmed fibrinolysis. In addition, a study with mixtures of various concentrations of fibrin degradation products (FbDP) and fibrinogen degradation products (FgDP) demonstrated a dose dependent intensity of band by immunoblot method. These results show that our method is favorable for the semi-quantitative analysis of fibrinolysis and fibrinogenolysis. We applied the method to 6 samples from patients with disseminated intravascular coagulation (DIC). Consequently, fibrinogenolysis was observed in all of 6 samples, in which fibrinogenolysis was more enhanced than fibrinolysis in one sample, and an equivalent degree of fibrinolysis and fibrinogenolysis were observed in 3 of 6 samples. Although our method was probably devoid of the ability to distinguish FgDP from degradation products of unstable fibrin, these findings indicate that fibrinogenolysis is, at any rate, enhanced in the majority of patients with DIC, besides fibrinolysis.     

Exercise-induced cerebral deoxygenation among untrained trekkers at moderate altitudes.

The pathophysiology of altitude-related disorders in untrained trekkers has not been clarified. In the present study, the effects of workload on cardiovascular parameters and regional cerebral oxygenation were studied in untrained trekkers at altitudes of 2700 m and 3700 m above sea level. We studied 6 males and 4 females at each altitude, and their average ages were 31.3+/-7.1 y at 2700 m and 31.2+/-6.8 y at 3700 m, respectively. The resting values of heart rate and mean blood pressure were not significantly different at 2700 m and 3700 m than at sea level. However, increases in these values after exercise were more prominent at high altitudes (heart rate increase = 51.6% at 2700 m and 70.4% at 3700 m; mean blood pressure increase: 19.0% at 2700 m and 17.2% at 3700 m). In addition, post-exercise blood lactate concentration was significantly higher at 3700 m than at sea level or at 2700 m (i.e., 7.6 mM at 3700 m, 3.8 mM at 2700 m, and 4.17 mM at 0 m, respectively). Exercise induced an acute reduction in the arterial oxygen saturation value (SpO2) at 2700 m and 3700 m (i.e., 11.2% reduction at 2700 m and 9.4% at 3700 m), whereas no changes were observed at sea level. The resting values of regional oxygen saturation (rSO2)--measured by a near infra-red spectrophotometer at sea level, 2700 m, and 3700 m-were nearly identical. Exercise at sea level did not reduce this value. In contrast, we observed a decrease in rSO2 after subjects exercised at 2700 m and 3700 m (i.e., 26.9% at 2700 m and 48.1% at 3700 m, respectively). The rSO2 measured 2 min and 3 min after exercise at 3700 m was significantly higher than the preexercise value. From these observations, we concluded that alterations in cardiovascular parameters were apparent only after an exercise load occurred at approximately 3000 m altitude. Acute reduction in cerebral regional oxygen saturation might be a primary cause of headache and acute mountain sickness among unacclimatized trekkers.     

Upward migration of the L-P shunt catheter into the cranial base

A rare complication of upward migration of the L-P shunt catheter into the cranial base is reported. A 59-year-old female with hydrocephalus underwent L-P shunt with a one-piece catheter. The catheter was secured with a clip but migrataed up to the cranial base without the clip becoming detached from the catheter. We assume that the catheter slipped at the position of the clip as the result of a strong force produced by lumbar movements, and that the clip may have acted like an one-way valve to push the catheter into the spinal canal. To prevent such a complication, we should tighten the clip as firmly as possible and use more clips, or use another type of clip which prevents slipping of a one-piece catheter such as the one described by Imaizumi et al.     

Analysis of glycosaminoglycans in rabbit cornea after excimer laser keratectomy

BACKGROUND/AIMS: The biochemical basis for the development of subepithelial opacity of the cornea after excimer laser keratectomy has yet to be fully defined. The aim of this study was to evaluate the alterations of glycosaminoglycans (GAGs) after excimer laser keratectomy. METHODS: Rabbit corneas were harvested on days 5, 10, 20, and 30 after excimer laser photoablation. The amount of main disaccharide units was determined by high performance liquid chromatography (HPLC). In addition, immunohistochemical studies were performed on corneal sections 20 days after the ablation. RESULTS: The concentrations of DeltaDi-0S at 5 and 10 days were significantly lower than before the ablation. DeltaDi-6S showed a significant increase 5 days after the ablation but DeltaDi-4S did not show any significant change. There was a significant increase in DeltaDi-HA at 20 and 30 days after ablation. In immunohistochemistry, the positive staining for DeltaDi-6S and hyaluronic acid was observed in the subepithelial region. These immunohistochemical results were well correlated with the HPLC findings. CONCLUSIONS: The increase in chondroitin-6 sulphate and hyaluronic acid may be related to corneal subepithelial opacity after excimer laser keratectomy.     

Different effects of trypsin inhibitors on intestinal gene expression of secretin and on pancreatic bicarbonate secretion in CCK-A-receptor-deficient rats

The effects of oral administration of two synthetic trypsin inhibitors (camostate and ONO-3403) and soybean trypsin inhibitor (SBTI) on cholecystokinin (CCK), secretin gene expression and pancreatic secretion were examined in CCK-A-receptor-deficient (OLETF) rats. The rats were fed chow containing 0.1% trypsin inhibitors for 7 days. To examine pancreatic secretion, the rats were prepared with cannulae to drain the bile and pancreatic juice separately, a duodenal cannula and an external jugular vein cannula. The animals were maintained in Bollman cages and the experiments were conducted 4 days after surgery. The levels of CCK mRNA were significantly increased by each treatment. The levels of secretin mRNA were significantly increased by camostate and SBTI, but not by ONO-3403. Bicarbonate secretion was significantly increased in rats treated with camostate and ONO-3403, but not SBTI, while protein secretion was not affected by any treatment. These observations suggest that increased bicarbonate secretion produced by synthetic trypsin inhibitors in CCK-A-receptor-deficient rats may not be due to secretin but due to ONO-3403 in the circulation.