The role of natural killer T cells in host defense to cryptococcal infection--a bridge from innate to acquired immunity]

Cryptococcosis is an opportunistic fungal infectious pathogen in immunocompromised patients with acquired immunodeficiency syndrome and hematological malignancies. The host defense to this pathogen is mediated mostly by cellular immunity. Th1-type cytokines including IFN-gamma, IL-12 and IL-18 play a pivotal role in this process. Recently, innate immunity mediated by NK, NKT and gammma-delta-T cells has garnered much attention from investigators. NKT cell has been identified as a particular cell population which recognizes glycolipids and participates in the development of tumor immunity and autoimmune diseases. In the present review, the accumulating knowledge on the roles of NKT cells in host defense to infectious pathogens are summarized with our own data on cryptococcal infection.     

Normothermic cardiopulmonary bypass: effect on the incidence of persistent postoperative neurological dysfunction following coronary artery bypass graft surgery

We retrospectively reviewed the records of 250 consecutive patients undergoing coronary artery bypass graft surgery (CABG) from January 1994 through January 1996 to determine the incidence of persistent postoperative neurological dysfunction after CABG and to compare normothermic and moderate hypothermic cardiopulmonary bypass (CPB). Normothermic CPB was used in 128 patients (36°–37°C) and hypothermic CPB (27°–28°C) in 122 patients. Postoperative neurological dysfunction included focal motor deficits, delayed recovery of consciousness (>24h) after surgery, and seizures within 1 week postoperatively. Persistent neurological dysfunction was diagnosed if complete resolution had not occurred within 10 days of surgery. The incidence of persistent postoperative neurological dysfunction was 4.1% in the hypothermic CPB group and 2.3% in the normothermic CPB group. There were no statistically significant differences between the two groups (P=NS). These results suggest that normothermic CPB did not increase the incidence of persistent postoperative neurological dysfunction compared to hypothermic CPB.     

Inhibition of HIV-1 replication and syncytium formation by synthetic CD4 peptides

Summary Only one peptide of CD₄ (amino acid residues 70–132) among 16 synthetic peptide fragments selectively inhibited HIV-1 replication and HIV-1-induced syncytium formation. Several smaller peptides within this region did not show any activity, except for the peptide (86–132) which showed somewhat lower activity.     

NEW METHOD OF STENTING TREATMENT FOR MALIGNANT DUODENAL STENOSIS: USING DOUBLE‐BALLOON ENTEROSCOPY

Recently, a self‐expandable metallic stent has been recognized for treatment of malignant duodenal stenosis. But the complications by stenting are important problems even now. In the present study, we report our new method of duodenal stenting by using of double‐balloon enteroscopy considered safe and effective.     

Iron in the enameloid of perciform fish.

It is known that a high concentration of iron is deposited in the enameloid of some teleostean fish. Previously, Suga et al. (1989) pointed out that the iron concentration in the enameloid is related to the phylogeny of fish rather than to the feeding habits, according to the results of quantitative iron analyses on the teeth of marine teleost fish of the Tetraodontiformes. In the present study, in order for the previous idea to be verified, quantitative iron analysis was made with an electron microprobe on the enameloid of fish belonging to the Perciformes, which is the largest group of teleostean fish in the world and consists of both marine and freshwater species. The enameloid of all the fish examined (57 species) contained high iron concentrations ranging from 0.2% to 10.2% at the surface or middle layer, whereas that of an advanced suborder, Tetraodontoidei, of the Tetraodontiformes was very low in iron, at a level which could not be discriminated from the background value of the emission intensity. The distribution pattern of iron in the enameloid was classified into at least two types, namely, type A, in which a high iron concentration was observed mainly in the surface layer, and type B, in which iron was deposited throughout the entire layer, although there were differences in concentration. There were some differences in the concentration and distribution of iron in the enameloid for the families; for example, those of the Scaridae had a type A distribution, with about 0.2% iron only at the surface layer, whereas those of the Cichlidae, Centrarchidae, and Acanthuridae, which showed a type B distribution, contained iron ranging from 2.9% to 10.5% at the surface or middle layer of enameloid. Such differences seemed to be associated with the difference in timing of the commencement of the iron deposition into the developing enameloid, which is probably related to the phylogeny of fish. There was no evidence to support the idea that the iron concentration in the enameloid is associated with the feeding habits of fish, as proposed by previous investigators.     

Combined aortic and mitral valve repair in active infective endocarditis

We describe a case of successful combined repair of the aortic and mitral valves for an indication of active infective endocarditis involving both valves. Mitral valve repair was achieved by vegetation debridement, fixation of the anterior mitral commissure, resection and suturing of the posterior mitral leaflet, and posterior annuloplasty with autologous pericardium. Aortic valve repair was achieved by vegetectomy and commissural plication. Postoperative clinical course was without signs of recurrent infection, and echocardiogram demonstrated mitral valve competence with trivial aortic regurgitation. We concluded that simultaneous valve repair is a viable option in the context of active endocarditis.     

Investigating endophenotype of endogeneous psychotic disorders]

Accumulated evidence from a number of previous structural MRI studies have revealed 1) the existence of abnormalities even at the brain structural level in subjects at an early stage of endogeneous psychotic illness, including schizophrenia and bipolar disorder, and 2) the existence of similar brain structural abnormalities to the patients even in individuals at high-risk of endogeneous psychotic illness. Recently, an increasing number of studies have investigated the associations between the functional polymorphism of candidate genes for susceptibility to schizophrenia and regional brain volume, a highly heritable trait marker, to uncover the linkage between the candidate genes and endophenotype of schizophrenia. Firstly, this review article overviewed recent literature examining the relationship between the candidate genes for susceptibility to schizophrenia and indices obtained from neuroimaging modalities. In contrast, a relatively limited number of previous studies examined associations between candidate genes for susceptibility to bipolar disorder and regional brain volume, although the high heritability of bipolar disorder has been reported as comparable to that of schizophrenia. Then, we discussed the possibility of endophenotyping of bipolar disorder and introduced our preliminary study. Finally, methodological considerations and future directions of endophenotyping of endogeneous psychosis were suggested.     

High Cell-Density Culture System of Hepatocytes Entrapped in a Three-Dimensional Hollow Fiber Module with Collagen Gel

Abstract: A compact three-dimensional (3D) module is needed for hepatocyte culture in order to develop an effective hybrid artificial liver system that can retain hepa-tocellular structure and differentiated functions. We treated the 3D module with collagen gel to entrap rat hepatocytes. This method yielded a high hepatocellular density (2 times 10⁷ cells/ml) over a period of 14 days and maintained the secretion of albumin and ureogenesis at the same level as the control monolayer method. The ammonia removal remained at 43% of the Day 0 value over 8 days of perfusion. Our data show that this approach may be useful for liver support therapy in an ex-tracorporeal circuit.