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Biomedical subjects

Y Kamiyama

Publications and source records attributed to Y Kamiyama.

At least 145 records · Page 8Linked to original sources

Stimulation of glycogen degradation by prostaglandin E2 in primary cultured rat hepatocytes.

Hepatocytes isolated from rats by the collagenase perfusion method were cultured as monolayers at concentrations of 0.4-1.1 x 10(6) attached cells/dish (9 cm2) for 1-3 days and the effect of prostaglandins on their glycogenolysis was studied. By use of [14C]glycogen-labeled cells, prostaglandin E2 (PGE2) was found to have a stimulatory effect on glycogen degradation at high cell density (more than 0.8 x 10(6) cells/dish) in 1-day cultures. PGE2 was maximally effective at 10(-7) M, increasing [14C]release from cellular [14C]glycogen to 2-3 times the basal level after 1 h incubation, and to plateau level within 2 h. PGE1, 16,16-dimethyl PGE2 and PGF2 alpha had similar effects, but PGD2 and dinor-PGE1 (a metabolite of PGE1 and PGE2 in hepatocytes) had no effect. This prostaglandin-induced glycogen degradation was observed in 1-day cultures, with a maximum between 20-30 h, but not in 2-day and later cultures. Treatment of hepatocytes with pertussis toxin potentiated PGE2-stimulated glycogen degradation, indicating that the effect involves a different pathway from that for inhibition of glucagon- and epinephrine-stimulated glycogenolysis by E series prostaglandins reported previously.

Animals↗

Preliminary pharmacokinetics and pharmacodynamics of an ultra-short-acting opioid: remifentanil (GI87084B).

Remifentanil is a newly synthesized 4-anilido-piperidine with an ester side chain susceptible to esterase metabolism. We evaluated the safety, analgesic efficacy, and pharmacokinetics of remifentanil in 48 male volunteers. Volunteers were randomized to receive increasing doses of remifentanil, alfentanil, or placebo. Analgesic efficacy was evaluated by increasing tolerance to a spring-loaded rod measured at the tibia and sternum at multiple time points. Respiratory depression was measured by changes in arterial blood gas tensions and peripheral hemoglobin oxygen saturation. Hemodynamics were continuously monitored by means of an intra-arterial catheter. Both remifentanil and alfentanil produced a dose-dependent increase in analgesia and respiratory depression. Remifentanil was 20 to 30 times more potent (milligram to milligram) than alfentanil when assessed by either analgesic efficacy or respiratory measures. The pharmacokinetics of remifentanil were best described by a biexponential decay curve. Remifentanil had a small volume of distribution of 0.39 (SD, +/- 0.25) L/kg (alfentanil, 0.52 +/- 2 L/kg), with a rapid distribution phase of 0.94 (SD, +/- 0.57) min and an extremely short elimination half-life of 9.5 (SD, +/- 4) min compared with an elimination half-life of alfentanil of 58 (SD, +/- 7.6) min. The t1/2 ke0 (half-time for equilibration between plasma and the effect compartment) of remifentanil for analgesia was calculated as 1.3 min. Thus, remifentanil appears to have a pharmacologic profile similar to other potent mu agonists, but with exceptionally short-lasting pharmacokinetics, which is likely to make it a very useful opioid for clinical practice.

Analgesics, Opioid↗

Clinical evaluation of a low junction of the cystic duct.

The point of the junction of the cystic duct with the common hepatic duct was studied by means of various preoperative and intraoperative cholangiographic procedures and by gross intraoperative examinations in 468 surgical patients with biliary diseases. The cystic duct entered the hepatic duct at a very low position and was consequently long in 39 patients. The clinical significance of this abnormally low junction of the cystic duct was studied in comparison with 358 patients with gallstones with a normal cystic duct-hepatic duct junction. In the low-junction group with a short common bile duct several complications, including gallstone pancreatitis (7 patients), the Mirizzi syndrome (7), confluence stones (2), gallbladder cancer (3), and congenital dilation of the cystic duct (1), were demonstrated preoperatively. The anomalous junction of the cystic duct with the common bile duct may cause stagnation of bile and/or reflux of pancreatic juice into the bile duct, producing a choledochopancreatic ductal junction and posing difficulties at surgery.

Adult↗

An assessment of percutaneous transhepatic biliary drainage in the correction of the metabolic capacity of the jaundiced liver by hippurate-synthesizing test.

Hippurate-synthesizing ability was investigated in patients with jaundice with percutaneous transhepatic biliary drainage (PTBD) in relation to hepatic metabolic capacity. In 16 patients with PTBD because of obstructive jaundice and 11 patients without hepatic disease, 1.77 grams of sodium benzoate was injected and the amount of hippurate synthesized and excreted in the urine collected at 30, 60, 120 and 180 minutes was measured (hippurate test). In patients with jaundice and patients in the control group, an almost linear increase was observed in the level of urinary hippurate after benzoate loading. However, the values of the patients with jaundice at one and two hours after the benzoate loading were significantly lower than those of the patients in the control group. Serum levels of glutamate oxaloacetic transaminase, glutamate pyruvate transaminase, alkaline phosphatase, gamma-glutamyl transpeptidase, total bilirubin and direct bilirubin were significantly decreased during PTBD (p < 0.05). Bilirubin levels were closely correlated with hippurate test values (r = 0.567, p < 0.05). Values were also correlated with the period of PTBD before the hippurate test was performed (r = 0.632, p < 0.05). Recovery in hippurate synthesizing ability was observed when the total bilirubin levels decreased to less than 5 milligrams per deciliter or PTBD was maintained for more than three weeks. Because hippurate synthesis is dependent on adenosine triphosphate supply in the hepatic mitochondria, the value of the hippurate test reflects the metabolic viability of the liver in relation to energy metabolism. It is also suggested that the steady maintenance of PTBD for three weeks or more with a decrease in total bilirubin level less than 5 milligrams per deciliter is necessary for full recovery of the metabolic capacity of the jaundiced liver.

Adult↗

[A case report of condyloma acuminatum of urethral meatus in a boy].

A 4-year-old boy was referred for treatment of papillary tumor at the urethral meatus. He was well until December 1990, when his mother noticed a tumor at the urethral meatus. The tumor was resected elsewhere. However, a similar tumor was noted again at the urethral meatus in May, 1991. The patient was admitted on September 16, 1991. Retraction of the phimotic foreskin revealed a well-demarcated papillary mass, approximately 2 x 2 mm in diameter, at the urethral meatus. There were no tumors on foreskin or glans. Under general anesthesia endoscopy was performed to locate other tumors at the urethra and bladder. No tumors were found elsewhere. Then the meatal tumor was resected surgically. Pathology was condyloma acuminatum. There was no recurrence one year after surgery. We also reviewed 24 boys with condyloma acuminatum, including 13 boys with a solitary condyloma at the urethral meatus, reported in Japan.

Child, Preschool↗

[Influence of epinephrine infusion on the metabolism of exogenous lipid emulsions after 70% hepatectomy in the rat].

We investigated the effects of epinephrine on the metabolism of a lipid emulsion administrated to rats after 70% hepatectomy. Sprague-Dawley rats were underwent 70% hepatectomy and then were given lipid total parenteral nutrition (lipid-TPN) for 96 h. To increase catabolism after hepatectomy, epinephrine (Bosmine) infused continuously with the lipid-TPN. With increasing doses of the epinephrine, weight loss and the increased urinary excretion of nitrogen and 3 methyl histidine were observed. This indicated that administration of epinephrine after hepatectomy produced a model of increased surgical stress. As the epinephrine dose increased the linoleic acid content of the hepatic phospholipids increased and the arachidonic acid decreased at 96 h after hepatectomy. Epinephrine apparently inhibited the activity of the delta 5.6 desaturase involved in the biosynthesis of polyunsaturated fatty acids, leading to changes of the cell membrane fatty acid composition that could possibly influence membrane function. Thus, the fatty acid composition of lipid emulsions for TPN should be tailored according to the severity of surgical stress, because the pattern of secretion of stress hormone is dependent on the degree of such stress.

Animals↗

Influence of mothers on school adjustment of continuous ambulatory peritoneal dialysis children.

In school children on continuous ambulatory peritoneal dialysis (CAPD), school adjustment is regarded as an important indicator for comprehensive medical care. The aim of the present study was to examine the influence of mothers on school adjustment of CAPD children. The children tended to indicate school maladjustment with school absenteeism and poor relationships with friends. The mothers were characterized by poor independence, poor achievement orientation, strong emotional reliance, and lack of social self-confidence, indicating emotional instability. The family environment, including the mother's psychological condition, was strongly associated with the children's maladjustment to school. The results suggested the necessity of comprehensive medical care for these children and their mothers.

Absenteeism↗

Clinical application of arterialization of portal vein in living related donor partial liver transplantation.

Arterialization of the portal vein was employed during hepatic arterial reconstruction in our first few clinical experiences of partial liver transplantation using liver grafts obtained from living related donors. This procedure reduced the time required for revascularization of the grafts to about 25 min, and could in fact reduce the ischemic phase of the grafts. Repeated practice of the clinical transplantation technique has shortened the time needed to complete vascular reconstruction, eliminating the need for this procedure in most of our subsequent cases. In many clinical cases, however, there may be emergency situations which require vascular reconstruction, resulting in a prolongation of ischemic phase and the deterioration of the cellular viability of the graft. In such situations, arterialization of the portal vein can be a useful way to prevent the prolongation of the ischemic phase and to rescue the graft.

Arteriovenous Shunt, Surgical↗

[Disappearance of lung metastases from hepatocellular carcinoma following bronchial arterial infusion of CDDP and MMC].

A 58-year-old man was admitted to our department because he had been diagnosed as hepatocellular carcinoma, which was located at S6 segment, and posterior segmentectomy was performed. After 6 months, right lung metastases of HCC were found and right bronchial arterial infusion of CDDP and MMC was performed twice. Dramatic effects were obtained such as disappearance of lung metastases. We emphasize the useful effect of CDDP and MMC for metastases of HCC.

Antineoplastic Combined Chemotherapy Protocols↗

Metabolic correction of plasma aminogram by pig or baboon liver cross-hemodialysis with an interposed membrane.

Our previous reports have shown that the patients with both grade 4 hepatic coma and arterial blood ketone body ratio (BKBR) of over 0.25 became fully alert after treatment by pig or baboon liver cross-hemodialysis, while those with BKBR below 0.25 died of hepatic coma without increase of BKBR. The present study shows the changes in plasma amino acids (AA) in 8 patients after treatment by cross-hemodialysis and itnravenous infusion of Fisher's solution. In all patients, the ratio of tyrosine plus phenylalanine to total AA concentration decreased (p = 0.012), and the AA molar ratio increased significantly (p = 0.007). In unrecovered patients, total AA and branched chain AA increased after cross-hemodialysis, while in the recovered patients total AA did not increase significantly. It is suggested that this metabolic support is effective in reducing the plasma levels of aromatic AA mainly oxidized in the liver, as long as BKBR remained over 0.25.

Aged↗

[Long-term follow-up study after pylorus-preserving gastrectomy for gastric ulcer].

The long-term follow-up study of pylorus-preserving gastrectomy (PPG) for benign gastric ulcer was described in terms of postoperative subjective symptoms related to gastrectomy and recurrent ulceration. Of 134 patients who underwent PPG, 5 patients died within one month after operation, 33 patients died in the follow-up period and 22 patients have not been traced. Seventy-four patients were available for a 3-24 year follow-up (mean 16.6 years) Recurrent ulcer developed in 4 patients, 1, 2, 9 and 11 years after surgery at the greater curvature of pre-pyloric region in all cases. Two patients underwent reoperation. These patients revealed higher gastric acid secretion as compared with that of one month after primary operation. But gastrin hypersecretion and G-cell hyperplasia were not recognized in these patients. According to detailed questionnaires, no patient showed the symptoms of dumping syndrome. The results indicate that PPG is preferable for the surgical treatment of gastric ulcer.

Adult↗

[Effect of total biliary diversion (cholecysto-jejuno-cystostomy) on gut hormone release and pancreatic structure in dogs].

In order to elucidate the effect to total biliary diversion (TBD) on gut hormone release and pancreatic structure, we performed cholecysto-jejuno-cystostomy (CJC) in 6 mongrel dogs using a small interposed intestinal segment between the gallbladder and the urinary bladder with ligation of the common bile duct. Twelve weeks after CJC, CJC was converted into cholecysto-jejuno-duodenostomy (CJD) to normalize luminal bile flow. Fat rich meal loading tests were carried out before and after these procedures. Plasma concentrations of GI hormones (CCK, PP, GIP) were measured by radioimmunoassay and morphological changes of the pancreas were evaluated by light and electron microscopic study. CJC significantly enhanced the basal levels and fat-stimulated release of both CCK and PP, however after CJD, these changes returned to the normal levels. Following CJC, fat-stimulated GIP release was completely inhibited, but recovered after CJD. Following CJC, hypertrophy of pancreatic acinar cells with profuse and dilated rough endoplasmic reticulum was observed, while after CJD this change returned to the pre-operative state. These results suggest that a feedback regulation may exist between luminal bile flow and CCK secretion, and pancreatic hypertrophy after TBD is, at least partly, due to the increased plasma CCK levels.

Animals↗

[Surgical results in Crohn's disease--an analysis in view of cumulative risk or recurrence and reoperation].

Forty nine cases with Crohn's disease operated at our department were analyzed in view of cumulative risk of reoperation and recurrence. Cumulative risk of reoperation was 22% at five years and 40% at ten years. Cumulative risk of recurrence after "curative" resection in thirty four cases was 53% at five years and 73% at ten years. Both risks were the highest in ileal type and the lowest in colonic type. Cumulative risk of relapse in ileocolic type after non-"curative" resection was 67% at five and ten years, which showed no significant difference with cumulative risk of recurrence after "curative" resection. Cumulative risk of recurrence after "curative" resection with proximal resection margin longer than 10 cm had no significant difference from the group with shorter margin. Cumulative risk of recurrence and reoperation after reoperation was a little higher than after initial operation, but they showed no statistical difference. In conclusion, there is no need to stick to "curative" resection, and it is enough to have the resection margin no longer than 10 cm. It is essential not to spoil the quality of life by excessive resection.

Adult↗

Effect of short-term essential amino acid-containing dialysate in young children on CAPD.

In young children on CAPD, hypoproteinemia and malnutrition are often observed. We used essential amino acid-containing dialysate (EAAD) to assess short-term effectiveness on serum amino acid concentrations in young children undergoing CAPD. EAAD consisted of a 540 ml, 1.5% glucose-containing dialysate and 100 ml of 7.4% essential amino acid (EAA) solution. Aside from methionine, all serum EAA rose during the 6 hour peritoneal dialysis cycle using EAAD, peaking at about 200% of pre-treatment level one hour after start of treatment. They then returned to near pre-treatment levels at the end of the cycle. However, serum methionine increased 680% of pre-treatment level, one hour after start and 390% at the end of the cycle. In the serum non-EAA tyrosine, which showed low levels in patients with chronic renal failure, increased after EAAD treatment. Other non-EAA, most of which showed increased levels in patients with chronic renal failure, decreased after EAAD treatment. These changes in serum amino acids suggest that EAA, absorbed from EAAD, may have increased uptake of non-EAA in protein synthesis. This may improve the nutritional status of young children on CAPD.

Amino Acids, Essential↗

[Effect of obstructive jaundice on the electrophysiological characteristics of the gastric mucosa and gastric acid secretion in rats].

To elucidate the effect of jaundice on the electrophysiological characteristics of the gastric mucosa and gastric acid secretion, gastric mucosal potential difference (PD) and gastric acid secretion were measured in rats with obstructive jaundice. Also transepithelial potential difference (TEPD), short circuit current (Isc) and transepithelial electrical resistance (Rt) were measured in the isolated gastric mucosa of rats with obstructive jaundice. Secondly, to confirm whether the alteration of these parameters were induced by jaundice and increased serum bile acids in the jaundiced rats, the effects of biliary drainage on the electrophysiological characteristics and gastric acid secretion, and the effects of bile acid (TCA) on TEPD, Isc, Rt were evaluated. PD, TEPD, Isc and gastric acid secretion were reduced in the jaundiced rats, and tended to recover after biliary drainage. TEPD and Isc were reduced significantly by TCA administration. These results suggest that active ion transport in the gastric mucosal cells and gastric acid secretion are impaired in jaundiced rats and the increased serum bile acid in jaundiced rats may cause these dysfunctions and the impaired active ionic transport function is improved by biliary drainage.

Animals↗