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Biomedical subjects

H Takagi

Publications and source records attributed to H Takagi.

At least 415 records · Page 23Linked to original sources
PubMed1996

Transient hepatofugal portal blood flow after hepatectomy in a patient with cirrhosis: report of a case.

We report herein the case of a 60-year-old man who developed hepatic failure with simultaneous transient hepatofugal portal blood flow after undergoing hepatectomy for hepatocellular carcinoma accompanied by cirrhosis with a splenorenal shunt. The transient hepatofugal portal blood flow was detected by color Doppler ultrasonography. Following this case report, the possibility of a relationship between hepatofugal portal blood flow, portal-systemic shunts, and postoperative hepatic failure is discussed.

Carcinoma, Hepatocellular↗
PubMed1996

Liberation of vasoactive substances and its prevention with thromboxane A2 synthase inhibitor in pig liver transplantation.

There are multiple causes of liver graft nonfunction in the early post-transplant period. Since a severe microcirculatory disturbance based on ischemia-reperfusion liver injury is considered to be the main underlying pathophysiology, it is suspected that various vasoactive substances are liberated after reperfusion of the graft. In order to investigate this matter, we conducted an experimental study with pig liver allotransplantation. Two groups of animals received donor grafts with or without thromboxane synthase inhibitor (sodium ozagrel), 1.25 mg/ kg body weight intravenously, given at the time of liver harvesting. All of the recipient animals in the treatment group (n = 10) survived longer than 7 days whereas three of ten animals in the control group died within 7 days. Serum lactate dehydrogenase (LDH) in the recipient serum at 1 h after reperfusion was significantly lower in the treatment group (915.1 +/- 167.3 U/l) than in the control group (1264.4 +/- 134.7 U/l). Serum thromboxane B2 (2261.7 +/- 1055.7 pg/ml) and endothelin-1 (6.3 +/- 2.2 pg/ml) after reperfusion in the treatment group were significantly lower than those in the control group (4220.0 +/- 1711.0 pg/ml and 11.2 +/- 3.1 pg/ml, respectively). Although serum angiotensin II after reperfusion tended to be lower in the treatment group than in the controls serum renin activity was less than 3 ng/ml in both groups of animals. There were no differences in the plasma endotoxin levels between the two groups. We conclude that the administration of sodium ozagrel to the donor animals provided better graft function in recipients than no such treatment. We speculate that the inhibition of thromboxane A2 production suppresses the liberation of other vasoconstrictive substances, preventing microcirculatory disturbance and, thereby, contributing to improved graft function after liver transplantation.

Angiotensin II↗
PubMed1996

High sensitivity to streptozotocin in herbivorous voles, Microtus arvalis, compared to mice.

Herbivorous voles, Microtus arvalis, have characteristics similar to herbivores in that their hepatic glycolytic enzyme activities are relatively low. The effects of a single low dose (100 mg/kg body weight) of streptozotocin (STZ) in voles were studied and the difference in sensitivity to or toxicity of STZ in voles and C57BL/6 mice was compared. In voles which received STZ, the cumulative incidence of glycosuria reached 53% by 4 weeks after administration. The diabetic voles showed marked increases in their blood glucose and plasma free fatty acid concentrations and a significant decrease in plasma immunoreactive insulin concentrations. Their hepatic hexokinase, glucokinase, glutathione peroxidase and glutamate dehydrogenase activities decreased significantly and lesions were widely observed in the liver, kidney and pancreas. The activities of glutathione peroxidase, a scavenger of H2O2, decreased significantly in their liver and pancreas. These changes were not observed in C57BL/6 mice which received STZ. The higher sensitivity to and toxicity of STZ in voles than in mice are considered to be caused by the characteristically low activities of glycolytic enzymes and glutathione peroxidase in the tissues of voles. Voles may be a good model for studying the mechanisms of cytotoxicity by STZ in herbivorous animals.

Animals↗
PubMed1996

Differentiation of species in the Bacillus brevis group and the Bacillus aneurinolyticus group based on the electrophoretic whole-cell protein pattern.

Ninety strains of eleven Bacillus species in the Bacillus brevis group and the Bacillus aneurinolyticus group were compared with the electrophoretic whole-cell protein pattern. The strains were separated into two clusters at the similarity of 55%. One cluster (cluster 1) was consisted of strains from the B. brevis group, and another cluster (cluster 2) was composed of strains from the B. aneurinolyticus group. The cluster 1 was separated into eight subclusters. Out of eight subclusters, seven subclusters contain strains from B. brevis, B. laterosporus, B. agri, B. reuszeri, B. choshinensis, B. formosus, and B. borstelensis. Another subcluster was further separated into two related clusters, which corresponded to B. centrosporus and B. parabrevis, and they were fused at the similarity of 76%. Cluster 2 was separated into two subclusters, which corresponded to B. aneurinolyticus and B. migulanus. The above eleven species showed characteristic patterns distinct from one another, and this correlated well with the published DNA relatedness data. The comparison of the electrophoretic whole-cell protein pattern proved to be useful for evaluation of taxonomic relationships among these taxa.

Bacillus↗
PubMed1996

Causes of rectal incontinence after sphincter-preserving operations for rectal cancer.

PURPOSE: Low anterior resection (LAR) is the treatment of choice for middle and high rectal tumors. Even though the rectal sphincter is preserved, some patients show a postoperative loss of rectal continence that may be recovered during follow-up. The purpose of this study was to collect clinical and manometric data before and after LAR to find possible explanations for incontinence. METHODS: Seventeen continent patients with rectal tumors located 10 cm above the anal verge were selected. Manometry was performed before and three months after surgery and when stable frequency of bowel movement was achieved (mean, 7 months). RESULTS: Immediately after the operations, 14 of 17 patients showed a certain degree of incontinence but recovered during follow-up; at the end of the study, only two patients reported minor soiling. Resting and squeeze pressures were moderately reduced after surgery and increased during the following six months without regaining preoperative levels. Rectoanal inhibitory reflex was present in 94.4 percent of patients before the operations and in 25 percent of them after surgery, but it was not associated with incontinence. Rectal sensation was significantly reduced, and its recovery was well correlated with decrease in the frequency of bowel movements. CONCLUSIONS: After LAR, there is a reduction in rectal pressures, suggesting damage to sphincter muscle fibers or innervation. There is also a reduction in rectal sensation related to loss in reservoir capacity, all of which may contribute to incontinence.

Adenocarcinoma↗
PubMed1996

Extrapancreatic nerve plexus invasion by carcinoma of the head of the pancreas. Diagnosis with intraportal endovascular ultrasonography.

CONCLUSION: The intraportal endovascular ultrasonography (IPEUS) could diagnose the second portion of the extrapancreatic nerve plexus invasion and provide precise information in operative strategy. But, the first portion was not visualized clearly owing to poor tissue penetration of the ultrasound beam, which may have reduced diagnostic accuracy. Improvement of the scanning area is expected to make intraportal endovascular US even more useful. BACKGROUND: Pancreatic cancer easily invades the retroperitoneal tissue, especially the extrapancreatic nerve plexus. We evaluated the extrapancreatic nerve plexus invasion of the pancreatic cancer with IPEUS. IPEUS was performed intraoperatively in 20 consecutive resected cases with carcinoma of the head of the pancreas. METHODS: IPEUS was performed with an 8-French, 20 MHz intravascular ultrasound catheter. IPEUS visualized the inferior pancreaticoduodenal artery (IPDA) in the extrapancreatic nerve plexus. The high-echoic area around the IPDA corresponds to the second portion of the extrapancreatic nerve plexus. The sonographic criterion for detection of the extrapancreatic nerve plexus invasion is low-echoic infiltration around the IPDA. RESULTS: Extrapancreatic nerve plexus invasion was confirmed with resected specimens in 10 patients. The IPDA could not be visualized in two patients. In 18 patients, the diagnostic accuracy of invasion was evaluated. For diagnosis of extrapancreatic nerve plexus invasion with intraportal endovascular US, the sensitivity, specificity, and overall accuracy were 87.5, 90, and 88.7%, respectively.

Adult↗
PubMed1996

Clonal analysis of nodular parathyroid hyperplasia in renal hyperparathyroidism.

Although it is well known that chronic renal failure induces parathyroid hyperplasia, the pathogenesis and development of this parathyroid lesion in this disease are poorly understood. Histopathologically, there is progression from diffuse to nodular hyperplasia, and each nodule consists of a single cell type with aggressive proliferative potential. Pathophysiologic and clinical investigations have suggested that neoplastic tumors may emerge from nodular hyperplasia. In this study the clonality of parathyroid tissue in nodular and diffuse hyperplasia in renal hyperparathyroidism was analyzed by a method based on restriction fragment length polymorphism of the X chromosome-linked phosphoglycerokinase gene and on random inactivation of the gene by methylation. DNA of peripheral lymphocytes was screened in 43 women undergoing parathyroidectomy for advanced renal hyperparathyroidism, and 10 of these patients appeared to be heterozygous. Fourteen specimens from these patients were available for clonal analysis. The analysis showed that all four specimens of diffuse hyperplasia were polyclonal, whereas all seven specimens from nodules in nodular hyperplasia and all three samples representing parathyroid tissue removed from forearm because of graft-dependent recurrence were revealed to be monoclonal. It is likely that the clonal origin of each nodule is independent. These results suggest that in renal hyperparathyroidism parathyroid glands initially grow diffusely and polyclonally, and then the cells in the nodules are later transformed monoclonally and proliferate aggressively. From the present study it can be concluded that nodular hyperplasia represents monoclonal parathyroid neoplasia, which might explain why patients with nodular hyperplasia in renal hyperparathyroidism are refractory to medical treatment, requiring parathyroidectomy. To prevent recurrences, nodular hyperplastic tissue should not be left at surgery.

Adult↗
PubMed1996

Adrenalectomy for treatment of Cushing syndrome: results in 122 patients and long-term follow-up studies.

Patients with Cushing syndrome (n = 122) who underwent adrenalectomy from 1957 through 1993 were reviewed for survival and complications. Of the 122 patients, 70 had adrenocortical adenoma, 30 Cushing's disease, 6 primary pigmented nodular adrenocortical disease (PPNAD), 7 other types of primary nodular hyperplasia, 5 adrenocortical carcinoma, and 4 ectopic ACTH syndrome. Sixty-five patients with adrenocortical adenoma are alive, and the survival rate was equal to the age-matched control population, when patients who died of the postoperative complication were excluded. Of the patients with Cushing's disease, 20 are alive; and 10 of 16 patients (63%) who were followed-up and evaluated had skin pigmentation. Four of sixteen patients (25%) developed Nelson's syndrome. Four PPNAD patients and five with other types of nodular hyperplasia are alive. Most of these patients underwent bilateral total adrenalectomy, but some patients remitted after unilateral adrenalectomy. All of five adrenocortical carcinoma patients and four with ectopic ACTH syndrome died within 2 years after operation. The prognosis for patients with adrenocortical adenoma after unilateral adrenalectomy is excellent, though it is important to avoid operative complications. The rapid cure of signs and symptoms of glucocorticoid excess after total adrenalectomy is ensured, and prognosis is satisfactory under careful glucocorticoid replacement, making total adrenalectomy an alternative treatment for Cushing's disease.

ACTH Syndrome, Ectopic↗
PubMed1996

Kyotorphin synthetase activity in rat adrenal glands and spinal cord.

Kyotorphin, an endogenous [Met5]enkephalin-releasing antinociceptive dipeptide (L-Tyr-L-Arg), is formed by kyotorphin synthetase from its constituent amino acids, L-Tyr and L-Arg, in the brain in an ATP-Mg(2+)-dependent manner. To elucidate the physiological role of kyotorphin in organs other than the brain, we examined the activity of kyotorphin synthetase in the rat adrenal glands and spinal cord. By Sephacryl S-300 gel-filtration chromatography of the soluble extracts from both the organs, the enzyme activity forming immunoreactive kyotorphin from L-Tyr and L-Arg in the presence of ATP and MgCl2 was detected in the fractions with the molecular mass of 200-300 kDa, being drastically reduced by the omission of ATP and MgCl2 from the reaction medium. The Km values of the partially purified adrenal and spinal kyotorphin synthetase for L-Tyr, L-Arg, ATP, and MgCl2 were close to those of the brain enzyme. The activity of adrenal kyotorphin synthetase was inhibited by some L-Arg analogues. NG-nitro-L-arginine methyl ester, alpha-methyl-L-ornithine and D-Arg, but not by NG-nitro-L-arginine and N-iminoethyl-L-ornithine. In the crude soluble extracts from the adrenal glands and spinal cord, kyotorphin was formed by kyotorphin synthetase, and also by the enzymatic processing of the precursor proteins, in the presence of physiological concentrations of L-Tyr and L-Arg in addition to ATP and MgCl2. Thus, kyotorphin synthetase resembling that in the brain is present in the rat adrenal glands and spinal cord. The present findings may predict a functional role of the L-Arg-kyotorphin pathway in these organs.

Adrenal Glands↗
PubMed1996

Analgesic effect of L-threo-3,4-dihydroxyphenylserine (L-DOPS) in patients with chronic pain.

Previous pharmacological studies using animals indicated that a systemic administration of L-threo-3,4-dihydroxy-phenylserine (L-DOPS), a precursor of noradrenaline, induces an antinociceptive effect and an increase in the CNS level of noradrenaline which serves an inhibitory role at the spinal dorsal horn and the supraspinal pain afferent system. The aim of the present study was to investigate the analgesic effect of L-DOPS in patients with chronic pain. We selected 18 patients with various kinds of pain. In nine patients, L-DOPS (tablets) was orally administered and pain was assessed by the visual analogue scale (VAS) before and after the L-DOPS administration. Administration of L-DOPS resulted in dose-dependent analgesia. The maximum analgesia (VAS change: from 10 to 4.1 +/- 0.9) was observed 60 min after an administration of 100 mg and it lasted for 2-5 h depending on the patient. In the other nine patients, oral administration of placebo tablets produced only a slight analgesia (VAS change: from 10 to (9.2 +/- 0.3). The difference between the L-DOPS-induced effect and the placebo-induced one was statistically significant. After repeated administration of L-DOPS for 4-5 weeks, neither tolerance nor side effects were observed.

Administration, Oral↗
PubMed1996

Coronary arterial perfusion during venoarterial extracorporeal membrane oxygenation.

The effects of venoarterial extracorporeal membrane oxygenation on left ventricular performance have not been studied in detail. Coronary arterial flow obtained by direct measurement with an electromagnetic flowmeter and blood gas analysis from the aortic root were tabulated during venoarterial extracorporeal membrane oxygenation 14 puppies, and these parameters were evaluated with respect to changes in the venoarterial extracorporeal membrane oxygenation flow. Unique automatic blood pumps generating pulsatile flow were used for the venoarterial extracorporeal membrane oxygenation bypass. Coronary arterial flow decreased as the extracorporeal membrane oxygenation flow increased (106 +/- 26 ml/min per 100 gm of left ventricle at 20 ml x min(-1) x kg bypass flow to 71 +/- 17 ml/min per 100 gm of left ventricle at 100 ml x min(-1) x kg bypass flow, p < 0.01). There were no significant changes in the mean or diastolic pressures in the ascending aorta despite changes in the extracorporeal membrane oxygenation flow. Arterial oxygen tension in the ascending aorta was not increased even under high-flow venoarterial extracorporeal membrane oxygenation. This result indicates that oxygenated blood from the extracorporeal membrane oxygenation circuit does not pass in a retrograde fashion into the aortic root and thus does not perfuse the coronary arteries. The diastolic aortic pressure did not correlate with the changes in extracorporeal membrane oxygenation flow. The decrease in coronary arterial flow is therefore predominantly caused by increased coronary arterial resistance. Tension-time index, an indicator of myocardial oxygen consumption, did not decrease with venoarterial extracorporeal membrane oxygenation. In conclusion, high-flow venoarterial extracorporeal membrane oxygenation causes undesirable hemodynamic effects on the left ventricle.

Analysis of Variance↗
PubMed1996

Preoperative embolization of gastric arteries for esophageal cancer.

BACKGROUND: We developed a novel treatment of preoperative embolization therapy in an attempt to prevent anastomotic leakage after esophageal resection. We report the results of this new treatment. METHODS: Preoperative embolization therapy (PET) was performed in 24 cases of esophageal carcinoma. The femoral artery was punctured, and celiac angiography was performed. The left gastric artery and splenic artery underwent embolization. The right gastric artery then underwent embolization at a site beyond the second or third branch to the gastric wall. With a laser flow meter the stomach tissue blood flow was measured before and after construction of the gastric tube, and the change in blood flow was compared. RESULTS: The average decrease in gastric blood flow was 23% in patients with PET and 65% in patients without PET. Twenty-one (88%) of 24 cases maintained more than 50% tissue blood flow in patients with PET and in 1 (8%) of 12 in patients without PET (p < 0.001 by t test). No serious complications occurred. CONCLUSIONS: Preoperative embolization therapy is a safe and uncomplicated technique, and tissue blood flow in the stomach was better preserved. This new technique is expected to reduce the frequency of anastomotic leakage after esophageal operation.

Adult↗
PubMed1996

Thrombocytopenia associated with hepatitis C viral infection.

BACKGROUND/AIMS: We investigated whether chronic hepatitis C infection is associated with thrombocytopenia. METHODS/RESULTS: Thrombocytopenia (<15 x 10(4) platelets/mu l) was diagnosed in 151 of 368 patients (41.0%) with chronic hepatitis C, a significantly higher proportion than that observed in patients with chronic hepatitis B (18.9%, p < 0.01). Elevated titers of platelet-associated immunoglobulin G were observed in 88.1% of patients with chronic hepatitis C and in 47.1% of patients with chronic hepatitis B. Platelet-associated immunoglobulin G titers were significantly higher in patients with chronic hepatitis C (87.3 +/- 10.1 ng/10(7) cells) vs. those with chronic hepatitis B (30.3 +/- 6.4) or the control subjects (p < 0.01). There was a significant negative correlation between platelet-associated immunoglobulin G titers and platelet counts in both chronic hepatitis C and B cases. Platelet-associated immunoglobulin G titers were significantly higher in patients with type C cirrhosis than in those with type B cirrhosis. Interestingly, HCV-RNA was detected by RT-PCR in the platelets from 11 of 14 patients with hepatitis C virus. CONCLUSIONS: These data indicate that chronic infection with hepatitis C virus may produce a significant autoimmune reaction to platelets, leading to thrombocytopenia.

Adult↗
PubMed1996

Intracaval endovascular ultrasonography for preoperative assessment of retrohepatic inferior vena cava infiltration by malignant hepatic tumors.

The accurate diagnosis of inferior vena cava infiltration is important not only for preoperative staging but also for performing surgery for hepatic tumor involving the inferior vena cava (IVC). We investigated the diagnostic value of intracaval endovascular ultrasonography (ICEUS) in the diagnosis of invasion of the IVC by a prospective study of 30 consecutive patients with hepatic tumors with possible invasion of the IVC. The procedure was performed using an 8F, 20-MHz intravascular ultrasonography (US) from the right femoral vein. Twenty-nine of the 30 patients underwent surgery, and the tumor was resected in 25 cases, including 3 cases of combined resection of the IVC. The diagnostic criterion for IVC infiltration with ICEUS was obliteration of a single echogenic layer of the IVC wall or intracaval tumor mass. The results of ICEUS were compared with those of computed tomography (CT), cavography, conventional US, and intraoperative US. Vascular invasion was identified in 7 of 30 cases and was subsequently confirmed by pathological examination of four resected specimens, including one autopsy and two operative findings. The sensitivity, specificity, and overall accuracy of ICEUS for the diagnosis of the IVC invasion was 100%, 95.8%, and 96.7%, respectively, against 85.7%, 60.8%, and 66.7% for CT, and 71.4%, 73.9%, and 73.3%, respectively, for cavography. The sensitivity, specificity, and overall accuracy of conventional US was 87.5%, 59%, and 66.7%, respectively; those of intraoperative US were 100%, 81.8%, and 86.2%, respectively. ICEUS is a useful technique that can precisely evaluate the IVC for possible hepatic tumor invasion.

Aged↗
PubMed1996

Severe acute metabolic acidosis and Wernicke's encephalopathy following chemotherapy with 5-fluorouracil and cisplatin: case report and review of the literature.

A 28-year-old woman with inoperable gastric carcinoma was given continuous infusion of 5-fluorouracil (5-FU) and low-dose cisplatin (CDDP) for 4 weeks while receiving intravenous hyperalimentation (IVH). Eleven days after her last treatment, she developed acute diplopia, deafness and gait ataxia, followed by severe confusion. She became markedly acidotic and hypotensive with a systolic blood pressure of 60 mmHg, necessitating intubation, dopamine treatment and hemodialysis for 7 h. She was also given thiamine. Thereafter, her blood pressure stabilized, the acidosis improved, and her deafness, diplopia, and confusion were resolved. This case suggests that FP (5-FU/CDDP) therapy toxicity, manifested as acute metabolic acidosis and Wernicke's encephalopathy, may be associated with IVH and thiamine deficiency.

Acidosis↗
PubMed1996

Identification of the chlB gene and the gene product essential for the light-independent chlorophyll biosynthesis in the cyanobacterium Plectonema boryanum.

We cloned a 6.0-kb HindIII fragment from the cyanobacterium Plectonema boryanum using the chloroplast chlB (ORF513) gene of the liverwort (Marchantia polymorpha) as a probe. An open reading frame (ORF508) encoding a polypeptide of 508 amino acid residues was found within the nucleotide sequence of the 4,437-bp HindIII-EcoRV subfragment. The deduced amino acid sequence of ORF508 shows very high similarity to that encoded by the liverwort chlB gene (72.7%). A mutant, YFB14, in which ORF508 was inactivated by the insertion of a kanamycin-resistance cartridge, was unable to synthesize chlorophyll, accumulating protochlorophyllide in darkness while synthesizing chlorophyll normally in the light. Thus, the chlB gene is the third gene that is essential for the light-independent reduction of protochlorophyllide. The other two genes are chlL and chlN, and the results suggest that the light-independent protochlorophyllide reductase consists of at least three subunits, which are encoded by chlL, chlN and chlB. Using an antiserum prepared against a ChlB-6xHis fusion protein expressed in Escherichia coli, we detected a protein with an apparent molecular weight of 58,000 in the membrane fraction of the cyanobacterium. These results indicate that either the cytoplasmic or thylakoid membranes could be the site of the light-independent reduction of protochlorophyllide.

Algal Proteins↗
PubMed1996

The involvement and sources of active oxygen in experimentally induced acute pancreatitis.

The involvement of active oxygen has been suggested in the development of cerulein-induced acute pancreatitis in rats. Previously, we directly detected pancreatic active oxygen (O2-) production in rats with cerulein-induced pancreatitis by using a supersensitive photon counter and a cypridina luciferin analogue (MCLA) that reacts specifically with O2- by emitting luminescence. In the present study, with the specific aim of determining the source of O2-, we prepared two groups of animals with cerulein-induced pancreatitis: those treated with allopurinol, a xanthine oxidase inhibitor; and those treated with nitrogen mustard, a leukopenia-inducing substance. In each of these two groups, pancreatic O2- production and the severity of pancreatic injuries were comparatively studied. In the leukopenic animal group, decreases in O2- dependent chemiluminescence and improvement in the pancreatic condition coincided. This suggests that neutrophils might be involved in experimentally induced pancreatitis as a source of active oxygen.

Acute Disease↗