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Biomedical subjects

A Hayashi

Publications and source records attributed to A Hayashi.

554 records · Page 31Linked to original sources
PubMedDate not supplied

Cerebroside of the dimorphic human pathogen, Candida albicans.

Structural studies on the cerebroside isolated from the yeast form of a dimorphic pathogen, Candida albicans were carried out using fast atom bombardment mass spectrometry (FAB/MS), proton magnetic resonance spectrometry, gas chromatography-mass spectrometry and usual chemical methods. The component sugar was only glucose attached to ceramide in a beta-configuration. The major fatty acid was 2-hydroxystearic acid (62%). The predominant long chain base was identified as 9-methyl-C18-sphinga-4,8-dienine which is widely distributed in fungi and reported to be essential to the fruit-inducing activity of fungi. Therefore, the structure of the main molecular species of the cerebroside was determined to be N-2-hydroxystearoyl-1-O-beta-glucosyl-9-methyl-C18-sphinga-4 ,8-dienine. Cerebroside prepared from the mycelial form of C. albicans has the same structure.

Candida albicans↗
PubMedDate not supplied

Pancreas retransplantation: outcomes of 20 cases.

The objective of this paper was to evaluate our initial experience with pancreas retransplantation. From January 26, 1996 to February 2005, 285 pancreas transplantations were performed, including 20 (7%) retransplants. The causes of primary graft loss were graft thrombosis in 11 (55%, 7 venous and 4 arterial); 4 (20%) chronic rejections; 2 (10%) ischemia/reperfusion injury; 1 severe graft pancreatitis; 1 primary nonfunction; and 1 sepsis. Venous drainage was placed in the iliac vessels in 14 (70%), vena cava in 5 (25%), and portal drainage in 1. The exocrine drainage was vesical in 16 (80%) and enteric in 4 (20%). In 14 cases (70%), the primary graft was removed before and in 6 (30%) at the time of retransplantation. Immunosuppression was based on antilymphocyte induction, tacrolimus, mycophenolate mofetil, and steroids in all patients. One-year patient and graft survivals were 95% and 85%. In conclusion, pancreas retransplants were feasible with results comparable to a primary pancreas transplantation.

Diabetes Mellitus, Type 1↗
PubMedDate not supplied

Influence of pancreas transplantation alone on native renal function.

Pancreas transplantation alone (PTA) has become an accepted treatment of nonuremic diabetic patients, when the risks of secondary complications of diabetes mellitus are greater than those of the surgical procedure and the posttransplant immunosuppression. As a decrease in native renal function is expected, we followed this parameter among patients who underwent PTA. From January 1997 through January 2005, we performed 69 PTA in 66 patients. All patients showed glucose hyperlability with hypoglycemic unawareness, or two or more diabetic complications as well as creatinine clearance (CrCl) > or = 45 mL/min. Immunosuppression was based on tacrolimus, mycophenolate mofetil and prednisone. Twenty-four hour CrCl were performed after all successful PTA. We divided patients in two groups according to the pretransplant CrCl: group 1, CrCl < or = 70 mL/min (n = 20) and group 2, CrCl > 70 mL/min (n = 25). The data were analyzed using Student's t-test (P < or = .05 was considered significant). Twenty-one patients were excluded from the analysis because of death (n = 5) or graft loss (n = 8) during the first year or follow-up shorter than 1 year (n = 8). The mean value of CrCl decreased 28.8% (85.0 +/- 31 versus 60.5 +/- 36 mL/min; P < .001). There was also a 39.3% reduction among group 1 subjects (P = .003), including 10 who displayed CrCl < or = 30 mL/min. There was also a 24.4% reduction among group 2 (P = .008), but no patient developed end-stage renal disease. In conclusion, native renal function decreased significantly after PTA, but was well tolerated among patients with CrCl > 70 mL/min. Patients with CrCl < 70 mL/min show a significant risk of worsened renal function.

Adult↗
PubMedDate not supplied

Magnifying prismatic lenses for vitrectomy.

PURPOSE: Viewing the fundus at higher magnification during vitrectomy makes surgical procedures much safer; however, the scope of magnification of the peripheral fundus has been limited. For better visualization of the periphery of the fundus, we have developed two new contact lenses called magnifying prismatic lenses. METHODS: The magnifying 15 degrees and 30 degrees prismatic lenses are made of a glass with a high index of refraction (n = 1.883). The lenses have a convex upper surface to provide a magnified view of the peripheral fundus. RESULTS: These magnifying 15 degrees and 30 degrees prismatic lenses provide an approximately 2x magnified view of the peripheral fundus. They also provide a more extensive view of the peripheral fundus than a regular (plano-concave) prismatic lens when the eye is tilted. CONCLUSION: The magnifying prismatic lenses are useful for viewing into the peripheral fundus with higher magnification.

Fundus Oculi↗
PubMedDate not supplied

Maternal stress induces synaptic loss and developmental disabilities of offspring.

Mild prenatal stress affects the serotonergic system in the hippocampus of rat offspring. Pregnant rats were daily exposed to mild stress treatments (consisting of crowding and saline injection) during days 15 to 21 of pregnancy. Their offspring were assessed by a series of biochemical, histological and behavioral tests. On 35 days after birth, 5-hydroxytryptamine (5-HT) level was decreased by 17% (P < 0.05), whereas 5-hydroxyindolacetic acid (5-HIAA) level was increased by 18% (P < 0.05) in the offspring of prenatally stressed rats. The metabolic rate (5-HIAA/5-HT) was increased by 49% (P < 0.01). Synaptic density in the hippocampus of prenatally stressed offspring was also decreased by 32% (P < 0.0001) on postnatal day 35. There was no significant group difference in the spatial learning acquisition test of the Morris water maze; however, in the reversal task, prenatally stressed 5-week old rats spent more time than control animals searching for the platform of the pool. Escape latency in the cued test showed no significant difference. Together with data in our previous studies, that have shown 5-HT to facilitate synapse formation and maintenance in the central nervous system, synaptic loss is suggested to occur in relation to changes of 5-HT system in the hippocampus of prenatally stressed offspring. This may be associated with reported changes in behavior and learning ability in prenatally stressed offspring.

Animals↗
PubMedDate not supplied

Experimental gene therapy against subcutaneously implanted glioma with a herpes simplex virus-defective vector expressing interferon-gamma.

We investigated the feasibility of local treatment or tumor vaccination with a herpes simplex virus (HSV) type 1-defective vector. The vector was engineered to express murine interferon-gamma (IFN-gamma) for experimental gene therapy against mouse glioma Rous sarcoma virus (RSV). The murine IFN-gamma gene was driven by the cytomegalovirus promoter. The helper virus (tsk) was thermosensitive; consequently, this vector could only proliferate at 31 degrees C. A high level of murine IFN-gamma expression was confirmed in vitro and in vivo by immunohistochemistry using anti-mouse IFN-gamma monoclonal antibody. This engineered vector (dvHSV/MulFN-gamma) inhibited the proliferation of mouse glioma RSV cells in vitro, and an intratumoral (i.t.) local injection of the vector caused i.t. necrosis in vivo. The immunological effect of dvHSV/MulFN-gamma was also examined in a mouse glioma RSV cell implantation model. A subcutaneous (s.c.) implant of 1 x 10(6) mouse glioma RSV cells after treatment with dvHSV/MulFN-gamma was rejected. However, the implant after treatment with an engineered HSV-defective vector containing an antisense nucleotide sequence of the murine IFN-gamma gene was not rejected. In addition, in another group of mice in which RSV cells treated with dvHSV/MulFN-gamma were implanted into a femoral (s.c.) region and nontreated RSV cells were implanted into a contralateral femoral (s.c.) region, the implanted RSV cells were rejected. The rejection of the implanted mouse glioma RSV was blocked by anti-asialo GM1, which was known to inhibit natural killer cell activity. These results revealed that the HSV-defective vector could realize a high efficiency of transfection to glioma cells through short-time treatment, and that the IFN-gamma gene transferred to the cells had the effect of tumor vaccination, which was suggested be related to natural killer cells. In conclusion, dvHSV/MulFN-gamma may be useful for the gene therapy of malignant glioma through either i.t. local injection or a practical tumor vaccination with ex vivo gene transfer.

Animals↗
PubMedDate not supplied

Immunoglobulin G subclass distribution of human anticolon antibodies in ulcerative colitis.

Immunoglobulin G (IgG) subclasses of anticolon antibodies were studied in patients with ulcerative colitis (UC) using enzyme-linked immunosorbent assay (ELISA). The concentrations of total serum IgG subclasses were also measured by ELISA. The values for total serum IgG subclasses in patients with UC were not significantly different from those in normal controls, while the ratio of IgG1 to IgG2 in the patients was significantly higher than that in normal controls. All four IgG subclasses of autoantibodies were demonstrated in the sera of the patients. IgG4 anticolon antibodies were detected most frequently (15 out of 18 patients, 83%). IgG2 was the next most prevalent (9 of 18 patients, 50%). The activity of anticolon antibodies in each subclass did not correlate with the concentration of the corresponding serum IgG subclass. Seven cell lines producing anticolon antibodies were obtained from the colonic mucosa of the patients by Epstein-Barr virus (EBV) transformation. IgG subclasses of anticolon antibodies secreted by these cell lines were also varied. IgG4 subclass was secreted by three EBV transformed cell lines, all of which produced IgG4 anticolon antibodies. These results suggest that all four different IgG subclasses could respond to the colon antigens and that various antigens in colonic mucosa or lumen may contribute to the induction of those autoantibodies. In addition, the prominence of IgG4 anticolon antibodies may support the pathogenic role of this subclass in UC as in other autoimmune diseases.

Adult↗
PubMedDate not supplied

Role of the lymphatic circulatory system in shock.

That the lymphatic vessel participates in the regulation of interstitial dynamics through its ability to contract and propel fluid and protein from the extravascular tissues back to the bloodstream has not been fully appreciated. The "lymph pump" appears to be regulated by local physiologic forces as well as neurogenic and humoral factors. We have assessed the effects of hemorrhage and endotoxin on the ability of the lymph vessel to propel fluid in sheep using a model system that permits the quantitation of lymphatic pumping in vivo without the complication of variable lymph inputs. A major blood loss was found to enhance lymphatic contractile activity and fluid pumping. Considering the large reservoir of fluid and protein in the interstitium and lymph, we speculate that stimulation of the "lymph pump" after hemorrhage might help to re-expand the vascular space. On the other hand, the intravenous administration of endotoxin inhibited lymphatic pumping, suggesting that impaired lymph propulsion in sepsis may contribute to edema by reducing the ability of the lymphatic vessel to remove extravasated protein from the tissues.

Animals↗
PubMedDate not supplied

Lack of rearranged Tpr-met mRNA expression in human gastric cancer cell lines and gastric mucosa and carcinoma.

The met protooncogene was activated by a rearrangement involving the fusion of tpr (1q25) and met (7q21-31) gene sequence in a human osteosarcoma cell line (HOS) incubated in vitro with N-methyl-N-nitro-N-nitrosoguanidine (MNNG). We examined the expression of tpr-met mRNA by means of the reverse transcription-nested polymerase chain reaction (RT-nested PCR) in human two gastric cell lines (MKN-1 and MKN-45), T-cell acute lymphocytic leukemia cell line (MOLT-4), and in gastric tissue samples including normal mucosa, intestinal metaplasia and carcinoma from three surgical specimens. A DNA fragment of 88-bp was amplified in MKN-1 and MOLT-4, 96-bp in MKN-45 and of 58-bp in all nine tissue samples including gastric carcinomas. The amplified DNA sequences were not homologous with the rearranged tpr-met gene. Our study indicated that rearranged tpr-met mRNA is not expressed either in human gastric carcinoma cell lines or in gastric mucosa and carcinoma.

Adenocarcinoma↗