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Biomedical subjects

Y Kishi

Publications and source records attributed to Y Kishi.

At least 55 records · Page 3Linked to original sources
PubMed2003

Left liver grafts for patients with MELD score of less than 15.

Left liver grafts are now seldom used for adult recipients of living donor liver transplantations because the left liver is believed to be insufficient to meet patient metabolic demands. At the University of Tokyo Hospital, left liver grafts have been limited to patients with fulminant hepatic failure or chronic hepatic failure with a model for end-stage liver disease (MELD) score of less than 15. Since 2000 25 adult patients received left liver grafts. The mean graft weight to standard liver volume ratio was 44%. The rates of acute rejection, vascular, and biliary complications were 24%, 0%, and 25%, respectively. All patients survived the operation and are doing well with a mean follow-up of 17 months. The present results suggest that left liver grafts provide acceptable results among patients satisfying our criteria.

Adult↗
PubMed2003

Induction of graft-versus-autoimmune (GVA) disease effect against refractory psoriasis by complete donor-type chimerism and graft-versus-host disease after allogeneic hematopoietic stem cell transplantation.

A 67-year-old man with AML, who had a 21-year history of psoriasis without remission, received a reduced-intensity transplantation from an HLA-identical sibling. The preparative regimen consisted of busulfan and fludarabine. Graft-versus-host-disease (GVHD) prophylaxis was cyclosporine and methotrexate. Psoriasis was completely resolved on day 18. The subsequent clinical course was uneventful until day 42, when psoriasis recurred at the same sites as before RIST. Peripheral blood examined on day 63 showed mixed chimerism with 54% recipient type. Cyclosporine was rapidly tapered off over the next 2 weeks. On day 90, 100% donor-type chimerism was confirmed. Subsequently, psoriasis improved simultaneously with the occurrence of mucositis and rash as a manifestation of GVHD. Scattered erythematous patches of psoriasis disappeared again by day 105. We initiated 0.5 mg/kg prednisolone on day 119, and resumed cyclosporine on day 133. At 7 months after RIST, he still suffers from chronic GVHD, but his psoriasis remains in remission for the first time in 21 years. The anti-psoriasis effect of the conditioning is mild and transient, while the graft-versus-autoimmunity effect, related to the induction of complete donor-type chimerism and GVHD, is more profound and persisting. A graft-versus-autoimmunity effect lies in the delicate balance between alloimmunity and immunosuppressant used for GVHD prophylaxis/treatment.

Aged↗
PubMed2003

Contrasting action of IL-12 and IL-18 in the development of dextran sodium sulphate colitis in mice.

BACKGROUND: Interleukin (IL)-12 and IL-18 are major interferon (IFN)-gamma-inducing factors that collaborate with each other. The present study was conducted to determine the distinct roles of IL-12 and IL-18 in the development of dextran sulphate sodium (DSS) colitis in mice. METHODS: Colitis was induced in IL-12p35(-/-), IL-18(-/-), IL-18 receptor(-/-) and control mice with DSS. Clinical and histopathological analysis was conducted using survival rate, weight loss score, diarrhoea score, bloody stool score and histological score. In addition, cytokine production by lamina propria mononuclear cells (LPMCs) was examined using the specific enzyme-linked immunoassay. RESULTS: IL-12p35(-/-) mice developed only a mild disease associated with no lethality and few histopathological abnormalities. In contrast, IL-18(-/-) and IL-18R(-/-) mice developed more severe colitis associated with high lethality and more histopathological abnormalities compared with control mice. LPMCs from DSS-fed IL-18(-/-) mice produced significantly higher amounts of IFN-gamma, while LPMCs from DSS-fed IL-12(-/-) mice produced lower amounts of IFN-gamma and tumour necrosis factor (TNF)-alpha compared with control mice. CONCLUSION: These results suggest that IL-18 might function with manners different from IL-12 at some pathological conditions in the development of colitis.

Animals↗
PubMed2002

Severe regimen-related toxicity occurring in a patient with XYY syndrome receiving allogeneic peripheral blood stem cell transplantation.

A 23-year-old man with chronic myelocytic leukemia (CML) in the first chronic phase underwent allogeneic peripheral blood stem cell transplantation (PBSCT) from his HLA-identical sibling. Pretransplant evaluations showed that he had a low risk of transplantation-related mortality and that the interval between the diagnosis of CML and PBSCT was only 6 months. However, he developed a variety of complications, including acute renal failure requiring hemodialysis, severe hepatic damage, hemorrhagic cystitis, and gastrointestinal hemorrhage leading to hypovolemic shock. Pathological examination of the colonic mucosa showed vascular endothelial damage and thrombotic lesions, leading to the diagnosis of thrombotic microangiopathy. Later, we found that he had the constitutional abnormality XYY. XYY syndrome is a frequent congenital abnormality, and mental disorders and congenital abnormalities of kidney and liver are common manifestations. Considering his clinical course, it was interesting that complications were severe in the organs which are frequently involved in cases of XYY syndrome. These organs may have poor function or poor reserves and may be more vulnerable to endothelial damage caused by high-dose cytotoxic chemotherapy. Patients with XYY syndrome might have a high risk of transplantation-related mortality.

Adult↗
PubMed2002

The value of the chest computed tomography halo sign in the diagnosis of invasive pulmonary aspergillosis. An autopsy-based retrospective study of 48 patients.

To evaluate the diagnostic value of a halo on computed tomography (CT) in the diagnosis of invasive pulmonary aspergillosis (IPA), we retrospectively reviewed chest CT scans and autopsy reports for patients who had been admitted to our hospitals for the treatment of hematological malignancy. Pulmonary complications were suspected in all patients and chest CT scans were taken within a month of death. We examined the association between autopsy and CT findings in 48 patients who were diagnosed as IPA (n = 17), candidosis (n = 4), zygomycosis (n = 2), infiltration of hematological malignancy (n = 12), bacterial pneumonia (n = 6), cytomegalovirus pneumonia (n = 2), pulmonary hemorrhage (n = 2), or pulmonary congestion (n = 1). Patients with IPA showed a variety of CT findings, including halo (n = 13), nodules (n = 14), granular shadows (n = 3), masses (n = 6), consolidations (n = 9), wedge-shaped consolidations (n = 1), and cavitation (n = 2). In contrast, 0, 11 and two of the 31 patients without IPA showed halo, nodules and masses, respectively. These signs were more frequently observed in IPA patients than in non-IPA patients. The CT halo, especially, seemed to be specific for IPA in hospitalized neutropenic patients with hematological malignancies who developed antibiotic-resistant fever. For CT findings other than these three signs, there were no significant differences between IPA- and non-IPA patients.

Adolescent↗
PubMed2002

Clinical significance of extra-pulmonary involvement of invasive aspergillosis: a retrospective autopsy-based study of 107 patients.

Disseminated aspergillus infection has a poor prognosis, but few reports have been published on extra-pulmonary involvement in aspergillosis. We reviewed 107 autopsy records of patients with invasive aspergillosis. Fifty-five patients had extra-pulmonary aspergillosis. Organs involved included heart, kidney, central nervous system, gastrointestinal tract, spleen, liver, thyroid gland and pancreas. Extra-pulmonary aspergillosis produces different manifestations according to involved organs. Risk factors associated with dissemination included cytotoxic chemotherapy within a month of death (P=0.0087). Lack of response to empiric or preemptive treatment of amphotericin B predicted IA dissemination (P=0.0328). To improve prognosis of IA, it is important to recognize clinical features of extra-pulmonary aspergillosis and to institute the aggressive anti-fungal treatment.

Adult↗
PubMed2001

S-Adenosyl-L-homocysteine hydrolase is sequestered into actin rods in Dictyostelium discoideum spores.

Here we show evidence that S-adenosyl-L-homocysteine hydrolase (SAHH) is linked to the actin cytoskeleton. Actin rods formed in Dictyostelium discoideum spores during the final stage of development are structurally composed of novel bundles of actin filaments. SAHH only accumulates with actin at this stage of development in the life cycle of D. discoideum. Recently SAHH is believed to be a target for antiviral chemotherapy and the suppression of T cells. Our finding may contribute to designing novel antiviral and immunosuppressive drugs.

Actins↗
PubMed2001

Enhanced platelet sensitivity to prostacyclin in patients in an active stage of Takayasu arteritis.

Patients in an active stage of Takayasu arteritis are often complicated with thrombosis in the affected vessels. We investigated whether alteration of platelet sensitivity to prostacyclin is involved in platelet function in these patients. Twelve female patients in an active stage (48.3+/-11.8 years, mean+/-S.D.), diagnosed clinically by a persistently elevated erythrocyte sedimentation rate (>40 mm/h) with typical symptoms, along with 10 gender- and age-matched patients in an inactive stage and 12 control subjects were enrolled. Half-maximal concentration (EC(50)) for platelet aggregation to collagen was determined in the presence and absence of 1 nM iloprost, a stable prostacyclin analog. Sensitivity of platelets to prostacyclin was quantified by the ratio of EC(50) (R) in the presence of iloprost to that in its absence. Patients in an active stage exhibited enhanced platelet aggregation, as demonstrated by significantly lower EC(50) to collagen and increased plasma thromboxane B(2) concentration. However, R values in these patients were significantly higher (4.00+/-1.05; P<.001) than those in the inactive patients or controls (2.58+/-0.62 and 2.43+/-0.68, respectively), suggesting enhanced sensitivity to prostacyclin in patients with active disease. Plasma 6-keto-PGF1 alpha levels were lower in the active patients than those in other groups of subjects. We conclude that platelets in an active stage of TA may be sensitive not only to collagen but also to prostacyclin. The increase in sensitivity of the platelets to prostacyclin could be a compensatory mechanism against a decrease in the prostanoid production, presumably associated with endothelial dysfunction.

6-Ketoprostaglandin F1 alpha↗
PubMed2001

Toward the creation of NMR databases in chiral solvents for assignments of relative and absolute stereochemistry: proof of concept.

[structure: see text] An NMR database approach in a chiral solvent allows us to predict both relative and absolute stereochemistry of an unknown compound without degradation and/or derivatization. N,alpha-Dimethylbenzylamine (DMBA) is a suitable solvent for this purpose. Using the C.5-C.10 portion of oasomycin A, the feasibility and reliability of this approach is demonstrated.

Anti-Bacterial Agents↗
PubMed2001

In vitro and in vivo anticancer activities of synthetic macrocyclic ketone analogues of halichondrin B.

Halichondrin B is a highly potent anticancer agent originally found in marine sponges. Although scarcity of the natural product has hampered efforts to develop halichondrin B as a new anticancer drug, the existence of a complete synthetic route has allowed synthesis of structurally simpler analogues that retain the remarkable potency of the parent compound. In this study, we show that two macrocyclic ketone analogues of halichondrir B, ER-076349 and ER-086526, have sub-nM growth inhibitory activities in vitro against numerous human cancer cell lines as well as marked in vivo activities at 0.1-1 mg/kg against four human xenografts: MDA-MB-435 breast cancer, COLO 205 colon cancer, LOX melanoma, and NIH: OVCAR-3 ovarian cancer. ER-076349 and ER-086526 induce G2-M cell cycle arrest and disruption of mitotic spindles, consistent with the tubulin-based antimitotic mechanism of halichondrin B. This is supported further by direct binding of the biotinylated analogue ER-040798 to tubulin and inhibition of tubulin polymerization in vitro by ER-076349 and ER-086526. Retention of the extraordinary in vitro and in vivo activity off halichondrin B in structurally simplified, fully synthetic analogues establishes the feasibility of developing halichondrin B-based agents as highly effective, novel anticancer drugs.

Animals↗