Biomedical subjects

A Kanazawa

Publications and source records attributed to A Kanazawa.

At least 73 records · Page 4Linked to original sources

PubMed1997

Concentrations of bile and serum endotoxin and serum cytokines after biliary drainage for acute cholangitis.

Endotoxin contributes to cholangitis. We measured concentrations of bile and serum endotoxin and serum cytokines after biliary drainage for obstructive jaundice with or without acute cholangitis. Patients who underwent percutaneous transhepatic cholangiodrainage (PTCD) in 1995 were classified as having acute cholangitis (group A; n = 11), having a history of acute cholangitis (group B; n = 5), or not having a history of acute cholangitis (group C; n = 13). Bile endotoxin was positive (above the cut-off value) in all patients in groups A and B, and in five patients in group C. The mean concentration of bile endotoxin was significantly higher in groups A and B than in group C. After PTCD, the bile endotoxin level decreased more slowly in group A than in the other groups. Before PTCD, the mean serum levels of IL-1 receptor antagonist (IL-1ra), IL-6, and IL-8 were higher in group A than the other groups. The serum levels of IL-1ra and IL-6 before PTCD were significantly higher when the acute cholangitis was more severe. The mean serum levels of cytokines increased just after PTCD and then decreased. In group A, the serum level of IL-6 at 5 h after PTCD was significantly correlated to the endotoxin level in bile at this time. Increases in cytokines may participate in the pathophysiological changes of acute cholangitis. Biliary drainage for acute cholangitis causes improvement by decreasing the bile endotoxin level addition to decreasing bile-duct pressure, thereby preventing excess production of inflammatory cytokines.

Acute Disease↗

PubMed1996

Postoperative monitoring of the oxygenation state of the graft liver in cases with hepatopulmonary syndrome.

Postoperative changes in the oxygen saturation of hemoglobin in the graft liver (graft SO2) were monitored by near-infrared spectroscopy in four cases complicated by hepatopulmonary syndrome. A plastic cylinder was placed in the abdominal wall, and optical measurements of the graft liver were obtained through this window. Our findings were as follows; (1) graft SO2 decreased after abdominal wall closure, and decreased further 1 day after surgery. (2) Graft SO2 was maintained despite severe hypoxemia, with partial pressure of oxygen in arterial blood as low as 50 mmHg. High hematocrit was beneficial for oxygenating the graft. (3) Graft livers could tolerate hypoxia with a graft SO2 as low as 20%. (4) It may be useful to monitor graft SO2 during the critical period after transplantation for the assessment of graft function.

Adolescent↗

PubMed1996

Donor-side photoinhibition in photosystem II from Chlamydomonas reinhardtii upon mutation of tyrosine-Z in the D1 polypeptide to phenylalanine.

When tyrosine-Z of the D1-polypeptide of the photosystem II from Chlamydomonas reinhardtii was changed to phenylalanine, the rapid donor to P680+ was lost, and P680+ accumulated on illumination. The rapid donation from tyrosine-Z was replaced by a slow electron transfer from an endogenous donor. Spectrophotometric measurements showed that carotenoids and chlorophylls were bleached by the P680+ either directly or indirectly upon illumination. The carotenoid bleaching was inhibited in the presence of SOD or catalase, but the reaction did not require molecular oxygen as an electron acceptor. These observations led us to conclude that active oxygen radicals, possibly hydroxyl radicals, take part in the destruction of carotenoids in the Y161F mutant. Possible mechanisms for the destruction are discussed.

Algal Proteins↗

PubMed1996

Extension of the indication for living related liver transplantation from children to adults based on resolution of graft size mismatch in relation to tissue oxygenation and metabolic load: a case report.

We extended the indication for living related partial liver transplantation from pediatric to adult cases. Our first case was a 49-year-old woman with primary biliary cirrhosis. Her sister's left lobe, weighing 280 g, was employed as a graft, and the graft weight/recipient's body weight ratio was calculated as 0.59%. To decrease the metabolic load to the relatively small graft, the total bilirubin was decreased from a maximum value of 75.0 mg/d1 to the most recent preoperative value of 36.2 mg/dl by plasma exchange. Intraoperative recovery of tissue oxygenation and its heterogeneity were satisfactory due to a relatively high blood supply. A postoperative decrease in bilirubin and increase in cholesterol esterification were facilitated, concomitant with regeneration of the graft, which weighed 280 g, to 860 cm3 at 3 weeks. Linear regression analysis with respect to tissue oxygenation and metabolic capacity obtained in pediatric cases were applied to this adult case.

Child↗

PubMed1996

Postnatal changes in activation of polyunsaturated fatty acid, acylation of lysophosphoglyceride, and phosphorylation of diacylglycerol in cortical gray matter of rat cerebrum.

Activation of polyunsaturated fatty acid, acylation of lysophosphoglyceride, and phosphorylation of diacylglycerol in postnatal developing rat cerebrum were studied in vitro, using cortical gray matter homogenates. The rate of n-3 and n-6 fatty acid activation was maximal at ten days after birth and minimal at adulthood. Acylation of lysophosphoglyceride was most active at the neonatal stage and gradually decreased with age. In addition, the amount of phosphatidic acid formed from 1, 2-dioleoyl-glycerol was also maximum at the neonatal stage, and then gradually decreased. These results suggest that the specific activity of glycerolipid synthesis in cortical gray matter declines during postnatal development.

Acylation↗

PubMed1996

[The dorsal approach in degeneratively changed cervical spine].

The posterior approach to the cervical spine was the only method of access to the spinal canal until the anterior approach was developed by Robinson and Smith, and Cloward. With the accumulation of experience in posterior decompression for cervical spondylotic myelopathy (CSM), successful laminectomy was guaranteed only when lordotic alignment of the cervical spine, wide and extensive laminectomy for adequate posterior shift of the spinal cord, and stability of the spine were ensured after surgery. The thick scar formation occasionally seen subsequent to postlaminectomy hematoma could lead to an unfavorable outcome. The insertion of surgical instruments, such as a Kerrison rongeur or a curette, into the spinal canal without being aware of how narrow the canal is, or uneven decompression of the spinal cord during resection of the laminae can impinge on or distort the spinal cord and result in deterioration of neurological function. Several authors have pointed out that postoperative loss of neural function is a hazard of surgical intervention. Owing to the poor results of conventional laminectomy for cervical compression myelopathy related to the problems mentioned above, Kirita developed extensive simultaneous decompression laminectomy to avoid distortion of the spinal cord by the edges of the resected laminae. Hattori devised an expansive Z-shaped laminoplasty in which the posterior wall of the spinal canal was preserved by Z-plasty of the prepared laminae. This was an attempt to prevent the invasion of scar tissue, i.e., the so-called laminectomy membrane, which was believed to be a cause of late neurological regression. He also expected that the laminae reconstructed by Z-plasty would provide support for the spine. The introduction of high-speed air-drills allowed successful development of this procedure. In 1977, Hirabayashi introduced an epoch-making laminoplasty, the expansive open-door laminoplasty. He described the advantages of this procedure as: possibility of decompressing multiple levels of the spinal cord simultaneously, better postoperative support of the neck, allowing earlier mobilization of the patients, prevention of postoperative kyphotic deformity of the cervical spine, and reduced mobility of the cervical spine postoperatively, which helps to prevent late neurological deterioration and progression of OPLL. Subsequent to the Hirabayashi laminoplasty, various modifications and supplementary procedures have been devised for further improvement of the safety and efficacy of decompression, and for improved stability of the spine. Aims, advantages and disadvantages of laminoplasty: The aims of the laminoplasty are to expand the spinal canal, to secure spinal stability and to spare the protective function of the spine. Preservation of mobility of the spine is also a goal of this procedure for multiple level involvement. Decompression can be extended along the nerve root by facetectomy. Preservation of the posterior spinal structures permits reinsertion of the nuchal muscles and the spinal ligaments after they have been totally or partially detached. This prevents kyphosis or listhesis of the cervical spine, which often develops after laminectomy, particularly in subjects below 50 years of age. Reconstructive procedures for reattaching muscles and/or ligaments to the spinous processes are added to the laminoplasty, improving the dynamic or ligamentous stability of the spine.

Cervical Vertebrae↗

PubMed1996

Clonal identification of Burkitt's lymphoma arising from lymphocyte-predominant Hodgkin's disease.

The occurrence of large cell lymphomas subsequent to, or concurrent with, lymphocyte predominant Hodgkin's disease (LPHD) is a well-documented phenomenon. We present a case of Burkitt's lymphoma of the bladder, occurring after the successful treatment of LPHD of a cervical lymph node. To evaluate the clonal relationship of the two tumours, we amplified the complementarity-determining-region 3 of two samples from paraffin-embedded slides, using the polymerase chain reaction (PCR). The sequences of the PCR products showed 96% homology to each other. These results indicate that the malignant clone of Burkitt's lymphoma arose from the corresponding LPHD.

Aged↗

PubMed1996

Insulin resistance as an independent risk factor for carotid wall thickening.

It has been reported that insulin resistance is associated with essential hypertension and that an aggregation of risk factors-hypertension, dyslipidemia, and glucose intolerance-together with insulin resistance leads to the more frequent appearance of coronary artery disease. We examined the relation between early asymptomatic atherosclerosis and these risk factors in 72 nondiabetic subjects with essential hypertension (41 men, 31 women) aged 50 to 59 years. Intima-media thickness and plaque formation of the carotid artery were assessed by B-mode ultrasonography, and insulin sensitivity was measured by the steady-state plasma glucose method. Lipoprotein profile was analyzed by ultracentrifugation. The intima-media thickness of the common carotid artery significantly correlated with systolic pressure; mean blood pressure; steady-state plasma glucose, indicating insulin resistance; fasting insulin; area under the curve of plasma insulin and glucose; body mass index; apolipoprotein B; apolipoprotein B in low-density lipoprotein; lower ratio of cholesterol to apolipoprotein B of low-density lipoprotein; and decreased high-density lipoprotein cholesterol. By multiple regression analysis, steady-state plasma glucose was the strongest risk, followed by lower high-density lipoprotein and systolic pressure. These three factors accounted for 54.9% of all the risk for increased intima-media thickness of the common carotid artery. In conclusion, insulin resistance was the strongest risk factor for carotid intima-media thickness, followed by lower high-density lipoprotein cholesterol and hypertension. An effort to maintain normal insulin sensitivity is essential for the prevention of early atheromatous lesions in essential hypertension.

Arteriosclerosis↗

PubMed1996

Clinical impact of insulin resistance syndrome in cardiovascular diseases and its therapeutic approach.

In subjects with coronary artery diseases (obstructive and vasospastic angina pectoris (AP)) who have no diabetes, hypertension, obesity and physical inactivity, insulin sensitivity was significantly reduced with compensated hyperinsulinemia on OGTT. Insulin resistance significantly correlated with coronary atherosclerosis score. In vasospastic AP (VAP), those who fulfilled more than 3 risk factors out of 5 (hyperinsulinemia, obesity, glucose intolerance, hypertension, dyslipidemia) consist of 70 and 40% for smokers and nonsmokers respectively. Insulin resistance syndrome who fulfilled all the criteria was 9-10% for VAP. In atherothrombotic brain infarction (ATTI) with the same exclusion criteria, the similar insulin resistance and hyperinsulinemia have been observed, but not in embolic (cardiac origin) or lacunar infarction. In ATTI, high TG and apo B with low HDL-chol were noted in blood. In essential hypertension without diabetes and obesity, hyperinsulinemia was noted in 25-35% and insulin resistance in 56-88%. Reduction of blood pressure with alpha blocker (bunazosin), ACE inhibitor (cilazapril), long-acting Ca++ blocker (amlodipine) significantly improved lowered insulin sensitivity. Insulin resistance rather than hyperinsulinemia is more closely associated with blood pressure. Cardiovascular diseases (vasospastic and obstructive AP, brain cortical artery diseases) are prone to develop diabetes because of insulin resistance and also promote the generation of cumulative risk factors resulting in a vicious cycle. Efforts to alleviate insulin resistance is crucial for the primary and secondary prevention of cardiovascular diseases.

Adrenergic alpha-Antagonists↗

PubMed1996

[Hydroxyl radical generation and post-ischemic reperfusion brain damage implications for neuroprotection].

We report the effects of the free radical scavengers, salicylic acid and bifemerane HC1, on the survival of hippocampal neurons in the Mongolin gerbil model of ischemia-reperfusion brain damage. In addition to performing histological examinations, we used the salicylate-trapping method to measure the amounts of hydroxyl radicals generated in the cerebral cortex and the hippocampus. Ischemia-reperfusion significantly reduced the number of neurons in the CA1 region of the hippocampus. The decrease was largely prevented by pretreating the animals with either salicylate, 20 mg/kg, or bifemerane HC1, 25 mg/kg. Administering salicylate to the animals 30 minutes after reperfusion was also effective, but bifemerane HC1 was ineffective when given after reperfusion. Two minutes after post-ischemic reperfusion, 2,3-dihydroxybenzoic acid levels were significantly elevated in the cerebral cortex and the hippocampus, and 2, 5-dihydroxybenzoic acid levels were significantly elevated in the hippocampus. The increase in 2,5-dyhydroxybenzoic acid in the hippocampus was suppressed by bifemerane HC1 given 30 minutes before exposure to ischemia. These results suggest that hydroxyl radicals are generated in the gerbil model of ischemia-reperfusion brain injury, and that salicylate and bifemerane HC1 partially prevent the loss of neurons in the hippocampus. Hydroxyl radical scavengers may be useful in reducing neuronal damage associated with ischemia-reperfusion injury.

Animals↗

PubMed1996

Anatomical and physiological problems of Segment IV: liver transplants using left lobes from living related donors.

We reviewed the problem of Segment IV in using left lobes from living related donors, in 18 left-lobe transplants performed on pediatric patients who ranged in age from 6.0 to 17.3 yr, and in body weight from 19.8 to 58.0 kg. The separate monitoring of oxygen saturation of hemoglobin in the liver sinusoid of segments, using a spectrophotometric technique, demonstrated a delay in re-oxygenation of Segment IV after the portal reflow, and revealed its return to comparable oxygenation with Segments II and III by the re-arterialization. Hemoglobin content, which was determined by the same technique, occasionally increased in Segment IV during the operation, implying sluggish microcirculation caused by inadequate hepatic venous drainage. These characteristic profiles on tissue oxygenation and hemodynamics in Segment IV should be considered when using left lobes as living related liver grafts.

Adolescent↗

PubMed1995

Lipid profiles of cerebral gray matter and livers of macaque monkeys Macaca fascicularis and Macaca fuscata fuscata: a comparative study during development.

The lipid and fatty acid profiles in cerebral gray matter and livers were studied in macaque monkeys (Macaca fascicularis and M. fuscata fuscata) of different ages. In cerebral gray matter, the phosphatidylcholine/phosphatidylethanolamine (PC/PE) ratio decreased in animals more than 3 years old, while the cholesterol/lipid-phosphorus ratios and the unsaturation indices increased, as compared with those in fetuses and newborns. The level of 22:6n-3 in PE of cerebral gray matter increased up to 3 years old, mainly by replacing 20:4n-6, whereas the level in phosphatidylserine did not change significantly with age. The hepatic lipid-phosphorus levels and PC/PE ratios were lower in newborns than in animals more than 3 years old. The level of 22:6n-3 in liver phospholipid did not change, while that of 20:4n-6 was lower in animals more than 3 years old than in newborns.

Aging↗

PubMed1995

A novel approach to mode of action of cationic biocides: morphological effect on antibacterial activity.

A new concept for the mode of action of cationic biocides is proposed in which the antibacterial activity of cationic disinfectants is ascribed essentially to molecular organizations of cations within aggregates, i.e. the activity is determined by the size of aggregates and number of active molecules comprising the aggregate. On the basis of the new concept, the morphological effect of disinfectants in aqueous solution on the antibacterial activity is discussed for low molecular weight phosphonium salts with single and double long alkyl chains (carbon number 14). The proposed new concept can be applied to all phenomena reported previously in antibacterial activity of cationic biocides and this concept is very important from the viewpoint of molecular design of more active cationic biocides.

Cations↗

PubMed1995

Polymorphic distribution and molecular diversification of mitochondrial plasmid-like DNAs in the genus Oryza.

Four kinds of circular plasmid-like DNA, designated B1, B2, B3 and B4, have been found in the mitochondria of rice (Oryza sativa L.). We analyzed the distribution of families of plasmid-like DNAs homologous to those of O. sativa in 40 strains of the genus Oryza with AA, BB, BBCC, CC, CCDD and EE genomes. Plasmid-like DNAs were observed only strains having AA, CC and CCDD genomes. The distribution patterns of strains with AA genome were highly polymorphic. We amplified the plasmid-like DNAs from strains with the AA genome by PCR and examined restriction fragments length polymorphisms (RFLPs). RFLPs were detected among families of plasmid-like DNA amplified from different strains. This result indicated that some mutations, such as base substitutions and the insertion or deletion of a small fragment of DNA, had occurred and had accumulated during the differentiation of strains with an AA genome.

Base Sequence↗

PubMed1995

Mitochondrial plasmid-like DNAs of the B1 family in the genus Oryza: sequence heterogeneity and evolution.

Four kinds of circular plasmid-like DNA, designated B1, B2, B3 and B4, have been found in the mitochondria of Oryza sativa L. with an AA genome. Three novel B1-homologous mitochondrial plasmid-like DNAs, designated, M1, M2 and M3, were isolated in the present study from strains with CC and CCDD genomes in the genus Oryza. We cloned and sequenced these DNAs and found that the sequences of these molecules have wide regions of homology. B1, M2 and M3 each lack about 300 bp of a region that is present in M1 and small repeats were found at the sites of deleted sequences. Therefore, we propose the hypothesis that the B1 family differentiated from a common ancient molecule that was similar to M1 via, probably, slipped mispairing during DNA replication at several stages in the evolution in the genus Oryza.

Base Sequence↗

PubMed1994

Reversible changes in the composition of the population of mtDNAs during dedifferentiation and regeneration in tobacco.

Differences in the composition of the population of mtDNAs between green plants and calli of tobacco were detected by DNA filter hybridization analysis. The altered composition of the population of mtDNAs observed in calli returned to the composition typical of green plants during the process of regeneration. Quantitative assays revealed that the changes were associated with the differentiation and dedifferentiation of cells since the extent of the change in composition depended on the degree of differentiation of a population of cells. The sequence that accumulated in dedifferentiated cells was shown to be a product of recombination mediated by a 9-nucleotide repeated element, one of which is located at the 5' region of atp6. Although the recombinant sequence was not detected by a hybridization procedure in green plants, its presence was identified by a more sensitive polymerase chain reaction method. The recombination event was shown to result in a deletion that prevents reverse recombination. Therefore, the reversion from the altered composition to the normal state of the population of mtDNAs during regeneration is explained not by recombination but by the preferential amplification of subgenomic mtDNA molecules.

Base Sequence↗

PubMed1994

Synthesis and antimicrobial activity of dimethyl- and trimethyl-substituted phosphonium salts with alkyl chains of various lengths.

Various phosphonium salts possessing single or double alkyl chains of various lengths (C10 to C18) were prepared as cationic biocides, and their antimicrobial activities against 11 typical strains of microorganisms including methicillin-resistant Staphylococcus aureus (MRSA) were evaluated. The phosphonium salts with long alkyl chains were found to show high levels of antimicrobial activity. Their activities depended strongly on the molecular structure, and a correlation between antimicrobial activity and molecular structure was observed. In the alkyltrimethylphosphonium salts, the bactericidal activity against S. aureus and Escherichia coli increased with increasing alkyl chain length, and the compound with the longest alkyl chain (C18) killed all the bacterial cells (ca. 10(7) cells per ml) within 30 min of contact at concentrations of 2.8 and 28 microM, respectively. In contrast, the bactericidal activity of dialkyldimethylphosphonium salts was found to decrease as the chain length of the substituents increased. It is significant that the phosphonium biocide containing double decyl groups exhibited the broadest spectrum of activity against microorganisms tested and showed the greatest bacteriostatic activity against MRSA (MIC = 0.78 micrograms/ml). Furthermore, we systematically investigated differences in bactericidal activity between the phosphonium salts and commonly available ammonium salts with the same hydrophobic structure. It was observed that the phosphonium salts showed an advantage over the corresponding ammonium salts in bactericidal activity and killing rate. For example, tetradecyltrimethyl- and didecyldimethylphosphonium chlorides killed all S. aureus organisms (ca. 10(7) cells per ml) within 60 and 30 min of exposure at 28 and 2.8 microM, respectively, while tetradecyltrimethyl- and didecyldimethylammonium chlorides which are representative of the existing cationic disinfectants did not kill all the bacteria even at the longest exposure time (120 min).

Anti-Bacterial Agents↗

PubMed1994

[A case of angiosarcoma with von Recklinghausen's disease].

We treated a patient with von Recklinghausen's disease and angiosarcoma. This combination has not been reported in Japan to the best of our knowledge. An emergency operation for massive gastrointestinal bleeding was performed on a 68-year-old woman with von Recklinghausen's disease, who had been known to have a retroperitoneal tumor; The bleeding was controlled and the tumor was also resected. Postoperative course was uneventful also but one month after operation intra-abdominal and intrathoracic bleeding developed, and the patient died of respiratory failure. Autopsy showed hemorrhagic lesions, which were diagnosed pathologically metastatic angiosarcoma. The possibility of hemorrhagic lesions in the patients with von Recklinghausen's disease should be kept in mind.

Aged↗