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Y Jojima

Publications and source records attributed to Y Jojima.

10 recordsLinked to original sources
PubMed2005

Optimal dose and target trough level in cyclosporine and tacrolimus conversion in renal transplantation as evaluated by lymphocyte drug sensitivity and pharmacokinetic parameters.

We evaluated the relative clinical potency of cyclosporine (CyA) and tacrolimus (Tac) using pharmacodynamic and pharmacokinetic parameters of the drug to obtain the most suitable converting dose and target trough level. The relative pharmacodynamic potency was examined by the mean ratio of drug concentrations giving 50% inhibition of blastogenesis of lymphocytes (IC50) in 66 chronic renal failure patients. The relative potency estimated from clinical pharmacokinetic parameters was examined by the mean ratio of each pharmacokinetic parameter value of CyA versus Tac. The pharmacokinetic parameters were estimated by 12-hour monitoring of drug blood concentrations in seven CyA patients and seven Tac patients. The mean IC50 ratio of CyA and Tac (CyA/Tac of IC50) was 25.1. The mean area under the concentration-time curve (AUC) ratio (CyA/Tac of AUC) was 25.5, the mean trough level (C(min)) ratio (CyA/Tac of C(min)) was 13.2, and the mean dose per body weight ratio was 25.2. The relative potency estimated from AUC that is the most reliable pharmacokinetic parameter for the estimation of clinical efficacy of calcineurin inhibitors appeared to agree with the relative pharmacodynamic potency estimated from IC50. The data suggest that TAC 25-fold more potent than CyA, which represents a suitable converting dose ratio, and that target trough level of CyA is about 13-fold greater than Tac based on CyA/Tac of C(min). We conclude that these relative values may be useful to estimate the suitable dose and target trough levels to convert between CyA and Tac.

Area Under Curve↗
PubMed2005

Evaluation of appropriate blood level in continuous intravenous infusion from trough concentrations after oral administration based on area under trough level in tacrolimus and cyclosporine therapy.

The target blood concentrations of tacrolimus (TAC) and cyclosporine (CYA) during continuous intravenous infusion (C(ss)) have been determined based on clinical experience. However, it is desirable that C(ss) should be set so that the AUC after intravenous infusion is equal to the AUC after oral administration (AUC(po)). Accordingly, we performed 12-hour monitoring of blood concentrations to calculate C(ss) from the blood trough levels (C(TL)) on 15 kidney recipients administered TAC and 12 recipients administered CYA (Neoral). We used an area under the trough level (AUTL) as a new pharmacokinetic parameter. The C(ss) was evaluated from C(TL), AUC(po), and AUTL was calculated to be C(ss) = C(TL) x (AUC(po)/AUTL). In addition, AUTL/AUC(po) ratio and blood peak/trough level ratio (C(max)/C(min)) were examined to compare pharmacokinetics of TAC and CYA. The formula for TAC was C(ss) = C(TL) x 1.40 and that for CYA, C(ss) = C(TL) x 2.55. The calculated target C(ss) of TAC was 1.40 times that of C(TL), which was similar to the present clinical C(TL). In contrast, the calculated target C(ss) of CYA was 2.55 times the C(TL), and therefore an extremely high C(ss) was necessary to obtain a sufficient AUC that will be available after oral administration. Consequently, intravenous administration of CYA twice a day was considered to be more appropriate to obtain sufficient CYA pharmacokinetics, rather than a continuous intravenous administration. We conclude that the formula, C(ss) = C(TL) x (AUC(po)/AUTL) was useful to calculate the target blood concentration of calcineurin inhibitors when changing from continuous intravenous infusion to oral administration of these drugs.

Administration, Oral↗
PubMed2004

Successful case of adult ABO-incompatible liver transplantation: beneficial effects of intrahepatic artery infusion therapy: a case report.

BACKGROUND: In Japan ABO-incompatible liver transplantation has been done on >100 occasions up to 2003. However, <30% are cases involving adults. The difficultly of ABO-incompatible liver transplantation is associated with the high frequency of humoral rejection and local disseminated intravascular coagulation (DIC), leading to many postoperative complications. We report a successful case of adult ABO-incompatible liver transplantation with the use of an intrahepatic artery infusion. METHODS: A 36-year-old man with Wilson disease, underwent living donor liver transplantation from an ABO-incompatible donor. The immunosuppressive therapy included multiple perioperative plasmaphereses, splenectomy, and treatment with tacrolimus, methylprednisolone, and cyclophosphamide. The dose and blood level of tacrolimus were the same as in ABO-compatible cases. In addition to these therapies, we administered an intrahepatic arterial infusion with prostaglandin (PG) E1 alone. RESULTS: After perioperative plasmapheresis and cyclophosphamide, antidonor blood group antibody titers remained undiluted and without vascular complications throughout the postoperative course, but there was a tendency for bleeding that continued for 10 days after transplantation. On postoperative day 10, a reexploration was performed for intraabdominal bleeding. During another operation on postoperative day 59 a biloma was found and drained. The patient has now survived for 120 days after transplantation with normal liver function. CONCLUSIONS: Beneficial effect of intrahepatic artery infusion with PGE1 seems to be useful in adult ABO-incompatible liver transplantation.

ABO Blood-Group System↗
PubMed1998

Isolation of myxobacteria from the marine environment.

In an attempt to isolate indigenous marine myxobacteria from coastal samples, we obtained two swarm forming bacteria. Both isolates formed cell aggregates which, at least in one isolate, developed to fruiting body-like structures consisting of a mass of myxospore-like cells. The optimum NaCl concentrations for their growth were between 2 and 3%, comparable to the NaCl concentration of seawater. This growth characteristic strongly suggests that the two isolates are specific marine bacteria. The 16S rDNA sequence studies indicated that the two isolates were related to the genus Nannocystis. Based on the phylogenetic distances between branches, we concluded that the isolates should be assigned to two new myxobacterial genera.

Culture Media↗
PubMed1996

Floating gallbladder associated with histologically distinct double cancers.

A case of unusually hypermobile floating gallbladder in a 79-year-old woman with histologically distinct double cancers of the gallbladder is described. The patient presented with an abdominal cystic mass, which was palpable with easy mobility from the right lower quadrant practically to the left upper quadrant. Exploratory laparotomy was performed and the cystic mass was found to be a floating gallbladder. The cystic duct was elongated and obstructed, and had a long mesentery. After the operation, latent double cancers of the gallbladder were discovered on histopathological examination. The obstruction of the cystic duct was due to chronic inflammation and had resulted in hydrops of the gallbladder. This was suspected to have played an important role in the carcinogenesis. We believe that this is the first report of a floating gallbladder associated with double gallbladder cancers.

Adenocarcinoma↗
PubMed1992

[Effect of gastric mucosal denervation on gastric carcinogenesis].

Numerous nerve fibers containing various neuropeptides are found in gastric mucosa. They play an important role not only in regulation of gastric secretion, motility and microcirculation but also in regeneration and differentiation of gastric mucosa. These nerve fibers are reduced in chronic atrophic gastritis which is considered a lesion closely related to carcinogenesis. We investigated the effect of gastric gastric mucosal denervation (vagotomy) on gastric carcinogenesis by using two experimental rat models in which chronic atrophic gastritis is induced by duodenogastric reflux. At first, following administration of MNNG, vagotomy with duodenogastric reflux enhanced gastric carcinogenesis compared to reflux only. At second, in the model of gastric remnant in which no carcinogenic agent was given, both B-I and B-II gastrectomy with vagotomy showed an increase of carcinoma and/or adenoma at the anastomotic site compared to those without vagotomy. Moreover, in vagotomized groups, there were an increase of labeling index of PCNA positive cells in gastric mucosa and a marked reduction of intramucosal neutral mucin in PAS-Alcian blue staining. These results indicate that the lack of gastric mucosal innervation not only induces the decrease of gastric mucosal cell function and cytoprotection but also enhances the increase of immature cell regeneration.

Animals↗
PubMed1977

Clinical significance of preoperative liver scintigraphy in gastric cancer.

The surgical and liver scintigraphic findings were compared for evaluation of preoperative diagnostic value in 146 cases of gastric carcinoma. Correct diagnosis was found in 95% with a false negative rate of 2.7% and a false positive rate of 27%. In all the false negative cases, the size of all space-occupying lesions within the liver was less than 3 cm. in diameter. In view of the high percentage of correct diagnosis (95%), we believe that the preoperative liver scintigraphy is very useful clinically. Furthermore, we documented that liver metastasis is a late complication of gastric cancer and suggest that new diagnostic tools are needed to assess the presence of nodal metastasis, serosal infiltration and peritoneal dissemination.

Adult↗
PubMedDate not supplied

Radiofrequency ablation of unresectable hepatic malignancies.

Since radiation and chemotherapy have little impact on survival and no prospect for cure, surgery offers the best potentially option in patients with liver tumors. However, a lot of patients with liver tumors is not resectable due to stage combined with health problems, or poor liver function reserve. In this study, our preliminary clinical reports in patients with unresectable liver tumors treatment with RFA have demonstrated radiologic evidence of tumor necrosis and complications. Multielectrode, radiofrequency probes were supplied by RITA Medical Systems (Mountain View, California). This study involved a total of 28 liver tumors in 19 patients (including 17 patients with hepatomas and 2 patients with metastases). The mean age was 68.9 years old. The size of tumor was more than 3 cm in 15 patients. The approaches to the tumor were laparoscopic in 1 patients and open surgical in 18 patients. Hepatic vascular occlusion was combined with RFA in 5 cases. The reasons for unresectable were defined as total bilirubin, ICGR 15, cardiopulmonary function and multiplicity. The efficacy of this RFA therapy was evaluated by preoperative and follow-up CT scans or tumor makers. There tumor necrosis was shown in 15 patients (78.9%). The survival rates at the time up to 12 months were 84.2% in 16 patients. The present study has demonstrated that the RFA is able to provide a safe and effective means in controlling liver tumors.

Aged↗