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Biomedical subjects

Y Kamiyama

Publications and source records attributed to Y Kamiyama.

At least 91 records · Page 5Linked to original sources
PubMed1998

Preoperative assessment for laparoscopic cholecystectomy: feasibility of using spiral computed tomography.

OBJECTIVE: The authors investigated the preoperative feasibility of using spiral computed tomography (SCT) after intravenous infusion cholangiography (IVC-SCT) for laparoscopic cholecystectomy. SUMMARY BACKGROUND DATA: In laparoscopic cholecystectomy, the aberrant or unusual anatomy of the bile duct and severe inflammation or adhesions around the gallbladder sometimes require a conversion to open surgery. METHODS: Laparoscopic cholecystectomies (LC's) were attempted on 440 patients, and preoperative IVC-SCT also was attempted in all of these patients. Using this spiral scanning technique, the bile ducts, cystic duct, and gallbladder were assessed for contour abnormalities, relative position, and filling defects. Forty-seven patients were diagnosed with having stones in their common bile duct or common hepatic duct. RESULTS: Three-hundred eighty-seven patients out of the 440 patients (88.0%) who were subjected to IVC-SCT had the length and course of their cystic duct successfully determined. Anomalous unions of the cystic duct were seen in 59 (15.2%) of 387 patients with respect to the operative findings, and 48 of 440 patients (10.9%) had severe adhesions to Calot's triangle and the surrounding tissues. In these 48 patients, 45 patients (94%) had a nonvisualized cystic duct on IVC-SCT. The preoperative assessment of the feasibility (dense adhesions obscuring Calot's triangle) of using IVC-SCT demonstrated that the sensitivity, specificity, and accuracy were 93%, 98%, and 94%, respectively. Five patients had to be converted to open surgery, and the overall morbidity rates for patients undergoing laparoscopic cholecystectomy was 0.9% (4 of 440). CONCLUSIONS: The most important factor in assessing the feasibility of using laparoscopic cholecystectomy is not the nonvisualized gallbladder, but the nonvisualized cystic duct on IVC-SCT. IVC-SCT may be of benefit to those patients scheduled to undergo laparoscopic cholecystectomy.

Adolescent↗
PubMed1998

Do intronic mutations affecting splicing of WT1 exon 9 cause Frasier syndrome?

The WT1 gene, one of the genes responsible for Wilms tumour, is thought to play a crucial role in the development of the kidneys and gonads. This gene encodes four protein isoforms resulting from two alternative splicing sites, one of which involves inclusion or exclusion of lysine, threonine, and serine (KTS) between the third and fourth zinc finger domains. WT1 is virtually always mutationally inactivated in patients with Denys-Drash syndrome. We analysed WT1 in eight patients who had been diagnosed as having this syndrome, and identified five previously unknown mutations affecting splicing donor sites of intron 9. These mutations affect alternative splicing. The isoforms retaining KTS are not produced. The clinical features of the patients with these intronic mutations were consistent with those of Frasier syndrome, characterised by a more slowly progressive nephropathy than Denys-Drash syndrome, associated streak gonads, and no Wilms tumour development. Our results indicate that WT1 isoforms, including/excluding KTS, have different functions in tumorigenesis and organogenesis of the kidneys and gonads.

Adolescent↗
PubMed1998

[Imaging studies of excretory urography and computed tomography scan for patients suffering from renal colic].

Renal colic mainly due to urolithiasis is one of the most common morbid conditions in urology and commonly seen in the urology emergency clinic. Imaging studies were performed to evaluate the upper urinary tract of 29 patients suffering from renal colic in the 2 years between November, 1994 and October, 1996. After intramuscular injection of the analgesic (pentazocine, 15 mg), all 29 patients were examined by excretory urography (IVP) at the time of the first visit. In some patients abdominal plain computed tomography (CT) scan was performed consecutively even when extravasation of the contrast medium was not seen. Spontaneous peripelvic extravasation was seen in 14 patients (11 males and 3 females) with urolithiasis; 7 of them were diagnosed by IVP, 5 by IVP plus CT scan and 2 with CT scan only. IVP imaging study followed by plain abdominal CT scan is useful even when the contrast medium is not extravasated on IVP in patients suffering from renal colic.

Adult↗
PubMed1998

[A clinical study of superficial bladder cancer with grade 3 components].

A retrospective study was done on 33 patients treated for superficial bladder cancer, pTa and pT1, with grade 3 components between 1986 and 1995. All patients had undergone transurethral resection of the tumor (TUR-Bt), which was followed by total cystectomy in 7 patients. Three patients died of pulmonary diseases or heart attack and 6 patients subsequently died of bladder cancer. The 2-year and 5-year disease-specific survival rates of these patients were 83% and 75%, respectively, and the mean duration of follow-up was 50 months. Comparison of the disease-specific survival rates for several factors revealed that the configuration and size of the tumors were significantly predictable factors for prognosis. In well-selected patients with grade 3 superficial bladder cancer, bladder preservation seems to be possible by TUR with or without adjuvant therapies. Hence further studies on a larger series are needed to elucidate more feasible and reliable prognostic factors to avoid unnecessary cystectomy and improve the quality of life of the patients.

Adult↗
PubMed1998

[Clinical studies on the quality of life in patients with ileal conduit].

Between August, 1985 and December. 1995 ileal conduit was performed in 36 cases of bladder cancer (30 males, 6 females). A survey based on a questionnaire was carried out on 15 patients to assess their quality of life (QOL) after the surgery. The questionnaire dealt with the working situation, appetite, sleep, defecation, bathing, travel, general health condition, satisfaction, sexual life and erection. Although only 64.0% of the patients returned to work, appetite, hours of sleep and bathing frequency showed only a slight decrease. We performed total cystectomy without using the nerve sparing method. After the operation, three patients could have an erection and enjoy sexual life. Because the ileal conduit resulted in few complications and only a slight reduction in QOL, it was considered an appropriate operation.

Activities of Daily Living↗
PubMed1998

[Significance of percutaneous endoscopic gastrostomy (PEG) in home medical care].

In recent years, reflecting our aging society, the importance of home medical care has been recognized in view of medical economic and patients' needs. We are actively responding to this trend by positioning home medical care as a "new comprehensive medical care" and by organizing home medical care team. Percutaneous endoscopic gastrostomy (PEG) was developed by Ponsky et al. in 1980. While it has been widespread in Europe and America, it has not been much used in Japan yet. PEG does not require complicated hand skills. It is less invasive and sufficiently applicable to severe cases. Also, since the nursing management is easy, it can be carried out at home. It is an enteral feeding method with superb features as described earlier, in view of home medical care that attaches importance to the quality of life (QOL). In this research, we investigated hand skills for PEG and problems with PEG nutrition. Also, we referred to new possibilities for PEG in home medical care. The success of home medical care will depend on the introduction of PEG, which plays a key role in home medical care.

Aged↗
PubMed1997

Extracellular glutamate and dopamine measured by microdialysis in the rat striatum during blockade of synaptic transmission in anesthetized and awake rats.

We investigated the effect of high dose tetrodotoxin (TTX) on microdialysis measurements of extracellular striatal glutamate and dopamine in normal female rats. Both halothane-anesthetized rats with acutely implanted microdialysis probes and awake rats with microdialysis probes implanted for 24 h were tested. Glutamate levels in awake rats were 45% higher than those of anesthetized rats. Extracellular glutamate remained TTX-insensitive regardless of TTX concentration, anesthesia, or time lapsed after probe implantation. In contrast, TTX reduced dialysate dopamine in all TTX concentrations tested. We speculate that the lower glutamate levels in anesthetized rats reflect the effect of anesthesia. Because glutamate is involved, either as a reactant or a product in a variety of reactions critical to intermediary metabolism in the brain, basal dialysate glutamate levels might indirectly reflect brain metabolism. Further, we conclude that extracellular glutamate collected during non-stimulated conditions is TTX-insensitive. The fact that glutamate levels are TTX-independent does not rule out that glutamate is synaptic in origin but rather demonstrates that it is not nerve impulse-dependent. However, the brain interstitial glutamate pool accessible to the microdialysis probe during control conditions is most likely isolated from the synapse, and therefore does not impose a neurotoxic potential.

Anesthesia↗
PubMed1997

Preoperative determination of the surgical procedure for hepatectomy using technetium-99m-galactosyl human serum albumin (99mTc-GSA) liver scintigraphy.

Technetium-99m-diethylenetriaminepentaacetic acidgalactosyl human serum albumin (Tc-GSA) is a new liver scintigraphy agent which binds to the asialoglycoprotein receptors. We evaluated the preoperative assessment for hepatectomy using Tc-GSA liver scintigraphy. Ninety patients with hepatocellular carcinoma were admitted for elective hepatectomy. Tc-GSA scintigraphy was conducted after the intravenous injection of Tc-GSA, and maximal removal rate of Tc-GSA (GSA-Rmax) was calculated using a radiopharmacokinetic model. Measurement of GSA-Rmax, conventional liver function, and 15-minute retention rate of indocyanine green (ICGR15) was carried out preoperatively. The relationships between liver functions, histological activity index (HAI), ICGR15, and GSA-Rmax values were estimated. A significant correlation was obtained between GSA-Rmax and ICGR15 (r = .534, P < .0001). Preoperative discrepancies between GSA-Rmax and ICGR15 values were seen in 15 patients. In these cases, the GSA-Rmax values correlated well with the total HAI scores (r = .595, P < .02), but no significant correlation was seen between the ICGR15 and HAI scores. Two patients died of postoperative liver failure within 2 months of the operation. These two patients were found to have severe discrepancies between their preoperative GSA-Rmax and ICGR15 values. We concluded that GSA-Rmax might be useful for selecting candidates for hepatectomy and that extended hepatectomies (di- and tri-segmentectomy) are high-risk surgical procedures in the case of low GSA-Rmax scores (below 0.35).

Adult↗
PubMed1997

Clinical evaluation of closed suction drainage following hepatectomy.

A prospective randomized study on 186 patients was conducted to determine the influence of closed suction drainage (n = 102) versus open drainage (n = 84) on the incidence of postoperative complications after elective hepatic resection. The patients were randomly allocated between the two groups. A total of 60 complications occurred in 31 of the 84 patients (36.9%) given open drainage, while 24 complications occurred in 15 of the 102 patients (14.7%) given closed suction drainage. The incidence of pleural effusion, postoperative ascites, and infected subphrenic collections was significantly lower in the closed suction drainage group than in the open drainage group, at 31% vs 16% (P < 0.05), 19% vs 3% (P < 0.01), and 17% vs 5% (P < 0.05) respectively. However, both groups showed similar rates of subphrenic hematoma and bile collection. These findings indicate that closed suction drainage significantly reduces the incidence of postoperative complications after elective hepatic resection.

Adult↗
PubMed1997

Assessing the eligibility for liver transplantation of patients with fulminant hepatitis.

The spleen to liver volume (S/L) ratio of 13 patients with fulminant hepatitis was determined using X-ray computed tomography (CT), and the correlation between S/L ratio and prognosis was evaluated. The S/L ratio of 6 patients who died was greater than 0.16, whereas that of the remaining 7 patients who survived was less than 0.15. These findings suggest that determining the S/L ratio using CT may be useful for assessing the eligibility of patients with fulminant hepatitis for liver transplantation.

Adolescent↗
PubMed1997

Stimulation of liver regeneration and function after partial hepatectomy in cirrhotic rats by continuous infusion of recombinant human hepatocyte growth factor.

BACKGROUND/AIMS: Radical resection is accepted as one of the most curative treatments for hepatocellular carcinoma. However, most patients have coexisting cirrhosis and their liver function is usually impaired. It is therefore important to stimulate the regeneration and function of the remnant cirrhotic liver after hepatectomy. Hepatocyte growth factor is a potent mitogen that has been suggested to play a crucial role in liver regeneration. METHODS: In this study, we performed 45% hepatectomy in rats with cirrhosis induced by thioacetamide, and administered recombinant human hepatocyte growth factor (rhHGF) with dextran sulfate by continuous infusion into the jugular vein with an infusion pump. RESULTS: rhHGF stimulated an increase in the wet weight of the remnant liver compared with untreated control rats. The proliferating cell nuclear antigen labeling index showed that this increase resulted from the stimulation of DNA synthesis. Serum levels of liver enzymes increased after hepatectomy, but returned to the prehepatectomy level more rapidly in rhHGF-treated rats than in controls. rhHGF increased hepatic protein synthesis above prehepatectomy levels and also markedly increased the serum levels of hepatic lipid metabolites. CONCLUSIONS: These results demonstrate that continuous intravenous infusion of rhHGF enhances the growth and function of the remnant liver in rats with cirrhosis after partial hepatectomy. Therefore, rhHGF may be useful after hepatic resection in patients with cirrhosis.

Animals↗
PubMed1997

The anti-inflammatory drug sodium salicylate inhibits nitric oxide formation induced by interleukin-1beta at a translational step, but not at a transcriptional step, in hepatocytes.

Recent evidence suggests that nitric oxide (NO) mediates cellular injury under the pathological conditions such as endotoxemia in the liver of rats. Regulation of NO production is crucial for improving the hepatic dysfunction. We have previously reported that, in cultured rat hepatocytes, a single cytokine interleukin-1beta (IL-1beta) stimulated a release of nitrite, an oxidation product of NO, into culture medium dose- and time-dependently. The objective of this study was to investigate an ability of the anti-inflammatory drug NaSA to affect the production of NO in hepatocytes. IL-1beta increased levels of inducible NO synthase (iNOS) messenger RNA (mRNA) with a maximal effect at 8 hours in primary cultures of rat hepatocytes. Nuclear factor-kappaB (NF-kappaB), that is an important nuclear factor protein in iNOS gene transcription in response to inflammatory mediators, also appeared in the nuclear fraction of hepatocytes 1 hour after addition of IL-1beta. Sodium salicylate markedly inhibited the NO formation induced by IL-1beta, but did not affect NF-kappaB activation and iNOS mRNA induction. Western blot analysis revealed that sodium salicylate (NaSA) blocked a step of iNOS protein synthesis. These findings indicate that NaSA may reduce hepatic injury by preventing the induction of NO formation in response to IL-1beta at the posttranscriptional step.

Animals↗
PubMed1997

Immunohistochemical studies of proliferating cell nuclear antigen and cathepsin D in transitional cell carcinoma of the urinary bladder.

Immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and cathepsin D was performed on 60 transitional cell carcinoma (TCC) specimens from 60 patients with bladder cancer. The percentage of PCNA-positive cells (PCNA-labelling index) was determined by counting 500 or 1,000 cells, and cathepsin D expression was graded according to the extent of immunoreactivity to anti-cathepsin D antibody. The PCNA-labelling index was significantly higher in high-grade and high-stage tumors compared to that in low-grade and low-stage tumors. Cathepsin D was highly positive in grade-1 tumors. In contrast, 82% of grade-3 tumors and 76% of advanced tumors showed negative or low reactivity to anti-cathepsin D. Groups of high PCNA-labelling index and negative cathepsin D had significantly poorer prognoses compared to those of the low PCNA group and cathepsin D highly positive group, respectively, in univariate analyses. However, neither of these two factors were independent prognostic factors in multivariate analyses. These results suggest that the PCNA-labelling index and cathepsin D expression may indicate the malignant potential of TCC and may be able to provide additional information for predicting survival when stratifying for grade of bladder cancer.

Adult↗
PubMed1997

Desensitization of the GABAA receptor shifts the dynamic range of retinal horizontal cells due to light and dark adaptation.

The effects of the GABAergic pathway on the dynamic range of the light response of cone-driven horizontal cells (HCs) in the carp retina were investigated using conventional intracellular recordings and computer simulations. The amplitude of the HC responses to repetitive test flashes was altered by background illumination in control Ringer's solution, but was not changed following the application of picrotoxin or bicuculline, which suggests that GABAA receptors mediate the subsequent change in light response. This phenomenon was simulated by introducing the desensitization mechanism of the GABAA receptor into a cone-HC network model. These results suggest that desensitization of the GABAA receptor shifts the dynamic range of the HCs due to light and dark adaptation.

Adaptation, Ocular↗
PubMed1997

A prospective trial of steroid cessation after renal transplantation in pediatric patients treated with cyclosporine and mizoribine.

We conducted a multi-center prospective study to evaluate the safety and efficacy of steroid withdrawal after renal transplantation in children. In 52 children (51 living-related donor transplants and 1 cadaver donor transplant), immunosuppressive therapy was started with cyclosporine (CyA), mizoribine (MZ), methylprednisolone (MPL) and anti-lymphocyte globulin. Administration of MPL was reduced to alternate days more than 6 months after transplantation, and attempts were made to withdraw it. Acute rejection was noted in 19 patients (36.5%) by 1 month after transplantation. The whole-blood CyA trough level using monoclonal antibody was 175.0+/-17.0 ng/ml in patients who developed acute rejection and 282.0+/-25.3 ng/ml in those who did not show acute rejection (p<0.01). During the 37 attempts at alternate-day MPL administration, clinical acute rejection was observed in only 1 patient and chronic rejection in 3. During 10 attempts to withdraw MPL, acute rejection was noted in 3 patients, but graft function recovered to the pre-rejection level after treatment of the acute rejection. At the last observation, graft function was lost in 3 patients, 22 were receiving MPL on alternate days, and MPL had been withdrawn from 7 for a mean period of 16.7 months. The survival rate of the patients and the grafts was 100% and 94% after an average follow-up period of 4 years. Evaluation of growth showed catch-up growth in all patients during the withdrawal period.

Anti-Inflammatory Agents↗
PubMed1997

[Epidural anesthesia for herniorrhaphy in a patient with severe dilated cardiomyopathy (DCM) under pimobendan control].

A 60-year-old man with severe DCM was scheduled for a herniorrhaphy under epidural anesthesia using fentanyl. Three months prior to operation, the patient suffered heart failure associated with life-threatening ventricular arrhythmia. The former was successfully treated with pimobendan as the main constituent of medication, but the latter was not responsive to various antiarrhythmic drugs with the exception of aprindine. On the day of operation and for two days postoperatively, pimobendan was administered daily. A sudden drop in systemic blood pressure and central venous pressure (CVP) during anesthesia, as well as the tendency to hypotensive status in the postoperative period were well regulated with continuous infusion of dopamine and dobutamine via CVP catheter probably due to the effect of up-regulation of pimobendan, together with adjustment of the volume of intravenous fluids. No dangerous ventricular arrhythmia were observed. Thereafter the patient made uneventful progress and was discharged on the 8th postoperative day.

Anesthesia, Epidural↗