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Biomedical subjects

T Imamura

Publications and source records attributed to T Imamura.

At least 343 records · Page 19Linked to original sources
PubMed1995

Current status of antimicrobial susceptibility in MRSA isolates typed by coagulase and phage typing in Okinawa.

The incidence of nosocomial infections with methicillin-resistant Staphylococcus aureus is of great concern in Japan and the developed world as a whole. Simple typing techniques like coagulase and phage typing are quick and useful for monitoring and evaluating these organisms. In view of this, the current status of antimicrobial susceptibility in Staphylococcus aureus (S. aureus) isolates in Okinawa typed by coagulase and phage typing was studied. Of 508 isolates, methicillin-resistant S. aureus (MRSA) comprised 54.3% (minimum inhibitory concentration (MIC) > or = 16 micrograms/ml). Coagulase type II and phage group III were the most prevalent, comprising 65.2% and 38%, respectively. These were followed by phage non-typable group and coagulase type III with 36.6% and 12.7%, respectively. Compared to a previous study conducted in 1989, there has been an increase of about 17% in the MRSA isolation rate with a concomitant increase of about 11% in the coagulase type II MRSA isolation rate and a decrease of about 27% in the isolation rate of coagulase type III MRSA. Using a panel of 16 antibiotics, coagulase type II MRSA were resistant to all except Arbekacin and Vancomycin. Arbekacin and Vancomycin were the sole antibiotics to which resistance was not expressed by any of the isolates. With regard to the methicillin-sensitive S. aureus (MSSA), coagulase type III and phase group III were the most prevalent, comprising 25.9% and 32.3%, respectively.

Bacteriophage Typing↗
PubMed1995

Chimeric TLS/FUS-CHOP gene expression and the heterogeneity of its junction in human myxoid and round cell liposarcoma.

Myxoid liposarcomas have a unique and specific t(12;16)q13;p11) chromosomal translocation. The breakpoint has recently been identified and shown to involve the TLS/FUS gene on chromosome 16 and the CHOP gene on chromosome 12. This translocation causes fusion of these genes resulting in the expression of a novel chimeric TLS/FUS-CHOP message. Using the polymerase chain reaction with primer sets derived from sequences of TLS/FUS and CHOP cDNAs, we could amplify three types of the fusion transcripts from seven of seven samples of myxoid and round cell liposarcomas. In six of the seven positive samples, two kinds of chimeric messenger RNAs were found that have been reported previously. However, the last sample had a novel chimeric message that had an extra sequence of 33 bp derived from the TLS/FUS gene. Thus, it was shown that these fusion transcripts had a varying extent of the sequence of TLS/FUS gene incorporated at the site of the fusion. However, the TLS/FUS-CHOP fusion transcripts were not detected in two pleomorphic liposarcomas or in three myxoid variants of malignant fibrous histiocytomas. Our findings indicate that in liposarcomas TLS/FUS-CHOP fusion transcripts have variations at the junction of chimeric messages, which was the case for Ewing's sarcoma. Detection of the chimeric message by reverse transcription polymerase chain reaction was also suggested to be a useful approach for the diagnosis of myxoid and round cell liposarcomas that have (12;16) translocation, and for distinguishing them from pleomorphic liposarcoma and myxoid variant of malignant fibrous histiocytomas.

Adult↗
PubMed1995

Death due to asphyxia linked to antipsychotic drugs.

A 46-year-old man with schizophrenia, died in hospital. Autopsy revealed numerous facial injuries and the direct cause of death was apparently asphyxia as a large amount of coagulated blood was present in the lower part of the trachea and bronchi. The blood derived from a lacerated wound of the mouth. The question was raised as to why expectoration was impossible and a toxicological analysis was directed to the antipsychotic drugs allegedly prescribed by doctors at the hospital. Using gas chromatography and gas chromatography/mass spectrometry, four different antipsychotic drugs including chlorpromazine, levomepromazine, zotepine and haloperidol were identified in the whole blood and tissues with concentrations being 1.91, 0.75, 0.61 and 0.48 micrograms/g in the blood, respectively. These levels were toxic to the extent that he could not expectorate and blood accumulating in the airway led to asphyxia and death.

Antipsychotic Agents↗
PubMed1995

[Statistical analysis of anesthesiologists' thinking patterns concerning regulation of the blood pressure and the concentration of inhaled anesthetics].

During surgery, the anesthesiologists adjust the concentration of inhaled anesthetics according to the change in blood pressure in order to achieve good control of anesthesia. Usually the thinking patterns of individual anesthesiologists differ from one to another. We obtained data from each anesthesiologist's thinking pattern concerning the regulation of blood pressure and the concentration of inhalational anesthesia. These patterns were analyzed statistically and compared for individual anesthesiologist. The results showed that anesthesiologists' regulation rules were formed independently of the 3 drugs and were specific to individuals. Some trends depending on institution were observed, but no statistically significant difference was found.

Anesthesia, General↗
PubMed1995

[A case of remission of recurrent carcinosarcoma of the uterus with massive ascites by carboplatin].

A case of remission of recurrent carcinosarcoma of the uterus with massive ascites by chemotherapy using carboplatin (CBDCA) is reported. A 75-year-old female was diagnosed with cancer of the uterine body. She underwent abdominal total hysterectomy with bilateral salpingo-oophorectomy, which revealed carcinosarcoma of the uterus penetrating the myometrium and reaching the serosa of the uterus. Eight weeks after, she developed abdominal distension, obstruction of bilateral ureters and bleeding tumor measuring 5 cm in diameter at the vaginal cuff ending. Acute retention of bloody ascites of more than 2500 ml was demonstrated. Abdominal centesis, aspiration of ascites and intraperitoneal administration of 600 mg of CBDCA were performed. Two weeks after single use of CBDCA, the ascites completely disappeared and there was recovery from anuria. The remission has lasted more than 4 months, which has suggested the efficacy of CBDCA for uterine carcinosarcoma.

Aged↗
PubMed1995

[A sensitivity of CRP determination of cord blood and neonatal serum for neonatal infection].

CRP was determined for 110 cord bloods and peripheral blood of 36 newborns collected within 72 hours after delivery for the early diagnosis of newborn infection. The determination of CRP was done by a counting immunoassay method using PAMIA-30(Sysmex, Kobe, Japan). Sample volume needed was small and the time for determination was short. Within-run and between-run precisions were satisfactory, with CV values being approximately 6%. The CRP of healthy newborns was lower than that of cord blood, and the mean value was 33.4 +/- 4.2 ng/ml and the value was not significantly different from that obtained from the newborn babies with turbid amnionic fluid or early rupture of a sac. The CRP gradually increased after delivery had a peak at 24 to 48 hours after delivery. This tendency was observed both in healthy and infected newborns. The data were divided into 6 groups depending on the time collected after delivery (6, 12, 24, 48, and 72 hours). The CRP of blood from infected newborns tended to have higher CRP than that of healthy newborns in each group. Increased amount of CRP (ng/ml/hrs) was calculated as ((CRP of peripheral blood at time x)--(CRP of cord blood))/x, and this value was significantly higher (p < 0.05) in infected newborns than in healthy newborns 12hrs and more after delivery. Thus, CRP might be useful for monitoring the newborn infection.

Biomarkers↗
PubMed1995

Brain death diagnosed by forensic analysis of drug distribution in human tissues.

Brain death was diagnosed by analyzing drug distribution in human tissues. Concentrations of diazepam and phenobarbital in human tissues, administered therapeutically to 3 patients in a critical condition, were determined by gas chromatography with a nitrogen phosphorus detector and gas chromatography-mass spectrometry. In 2 patients administered drugs while the brain was functioning, drug concentrations in the brain were high compared with those in the other tissues. In the other patient given the drugs after vital signs of the brain ceased, the level of drugs in the brain was much lower than seen in other tissues. We propose that a forensic diagnosis of patients who are brain dead can be made by comparing the concentrations of drugs in the brain given at the time of critical condition with concentration of these agents in other tissues. When cerebral function ceased can be roughly estimated by the variable distribution patterns of drugs and time of administration of these drugs.

Adult↗
PubMed1995

[Analysis of the anesthesiologists' action patterns concerning regulation of the blood pressure and the concentration of inhalational anesthesia].

The action pattern of each anesthesiologist is different. We have developed a computer program simulating anesthesiologists' action patterns during operation and have extracted the action patterns of anesthesiologists using a computer program. The simulation program was designed to gather data on anesthesiologists' response to the change in blood pressure. The results indicate that the action pattern differs significantly from one anesthesiologist to another in responding to the change in blood pressure. That of one particular anesthesiologist remained the same, regardless of the agent used. His action pattern is directed only by the value of MAC and according to his own personal principle.

Anesthesia, Inhalation↗
PubMed1995

Effect of the oral administration of sepimostat mesilate on cerulein induced acute pancreatitis in rats.

The effect of a potent protease inhibitor, sepimostat mesilate (CAS 103926-82-5, FUT-187), on acute interstitial edematous pancreatitis induced by a supramaximal dose of cerulein, a cholecystokinin (CCK) analogue, was evaluated. The serum amylase activity increased 18-fold over normal control after the infusion of cerulein at 5 micrograms/kg/h for 6 h. The serum lipase activity showed a 235-fold increase. An elevated pancreatic water content, pancreatic interstitial edema, inflammatory infiltration and vacuolization of the acinar cells were found. Redistribution of cathepsin B shifted from the lysosomal pellet fraction to the zymogen granule pellet fraction was noted in the early stages. All these parameters of pancreatitis mentioned above were inhibited by FUT-187 pretreatment at doses of 30 to 300 mg/kg. These observations suggest that FUT-187 inhibits the redistribution of cathepsin B shift from the lysosomal fraction to the zymogen fraction in cerulein-induced acute pancreatitis and improves the parameters of acute pancreatitis.

Acute Disease↗
PubMed1994

Two naturally occurring mutations in the kinase domain of insulin receptor accelerate degradation of the insulin receptor and impair the kinase activity.

We identified two novel heterozygous missense mutations of the insulin receptor gene: the Asp1179 mutation in one family and the Leu1193 mutation in two unrelated families with extreme insulin resistance. In these patients, the number of insulin receptors on the cell surface was found to be markedly decreased by insulin binding and surface labeling studies in transformed lymphocytes. Insulin binding to the transfected COS 7 cells and Rat-1 cells with both mutant cDNAs was also decreased to 5-31% of normal, and the mutant insulin receptors showed a markedly decreased kinase activity. Although biosynthetic labeling studies revealed that both mutant receptors were synthesized as 190-kDa proreceptors, the degradation of the mutant proreceptors was 2-fold faster than that of the wild type proreceptors. However, the degradation rate of the mutant receptors on the cell surface was comparable to that of wild type insulin receptor. These results suggest that the Asp1179 and Leu1193 mutations in the kinase domain are unique in causing decreased insulin receptor number on the cell surface by accelerated intracellular degradation, and that insulin resistance in these patients is mainly due to the decreased receptor number rather than impaired kinase activity.

Adult↗
PubMed1994

Leu 193 mutation in the cysteine rich region of the insulin receptor inhibits the cleavage of the insulin receptor precursor but not insulin binding.

To characterize the Leu 193 mutant insulin receptor, which was found in a patient with extreme insulin resistance, the mutant insulin receptor was overexpressed in Rat-1 fibroblasts by transfection of mutated insulin receptor cDNA. In the pulse-chase experiment, the cleavage of the proreceptors to the matured receptor subunits was impaired in the cells expressing Leu 193 insulin receptor and therefore, the mutant proreceptors were accumulated in the cell. Insulin bound to the Leu 193 insulin receptor on the cell surface with normal affinity, although the mutation was in the alpha-subunit of the insulin receptor. Therefore, the Leu 193 mutation impaired proreceptor cleavage but not insulin binding.

Animals↗
PubMed1994

DCC gene alteration in human endometrial carcinomas.

The present study was undertaken to define the gene(s) of importance on the long arm of chromosome 18 (chromosome 18q) in endometrial carcinomas. We analyzed loss of heterozygosity (LOH) at 3 loci on chromosome 18q and DCC gene expression by the reverse-transcriptase/polymerase chain reaction (RT-PCR) method. Among 61 tumors that were informative, 16 (26%), estimated to be a minimum number, showed allelic losses at one or more chromosome 18q loci. Deletions in these tumors possibly involved the region within or near the chromosome 18q 21.3 band where the DCC gene was localized. Moreover, the incidence of altered DCC mRNA expression was high in these tumors. Appropriate transcription was lost in 5 of 7 (71%) carcinoma cell lines in addition to 14 of 28 (50%) surgically resected tumors. Histopathological differentiation and clinical stage of disease were not related to LOH frequency or to DCC mRNA expression. These results suggest that the target for allelic loss on chromosome 18q seen in endometrial carcinomas is the DCC gene, and that inactivation of this gene may be critical for the development of most endometrial carcinomas.

Alleles↗
PubMed1994

Increased actin cable organization after single chromosome introduction: association with suppression of in vitro cell growth rather than tumorigenic suppression.

We previously showed that introduction of a single human chromosome 1, 6, or 9 derived from normal fibroblasts into HHUA endometrial carcinoma cells resulted in suppression of tumorigenicity. The tumorigenic suppression was accompanied by remarkable morphological changes in the microcell hybrids containing an extra copy of chromosome 1. The study presented here was undertaken to search for target cytoskeletal components affected by chromosome 1 transfer into endometrial carcinoma cells. We found that the microcell hybrids containing an extra copy of chromosome 1 were characterized by intracellular actin bundle formation and an excessive accumulation of actin and vinculin. The latter was a result of increased stabilization of the proteins. Additionally, chromosome 3 introduction into RCC23 human renal carcinoma cells resulted in prolongation of cell division and in senescence of a significant proportion of the microcell hybrids. In these microcell hybrids, the intracellular actin network was also reorganized, but the amounts of actin and vinculin protein were not increased. These findings suggest that the increased actin organization, which appeared not to cause tumorigenic suppression in the microcell hybrids, is associated with complementation of tumor suppressor genes and senescence by multiple mechanisms.

Actin Cytoskeleton↗
PubMed1994

Cell cycle-dependent nuclear localization of exogenously added fibroblast growth factor-1 in BALB/c 3T3 and human vascular endothelial cells.

Previous studies have shown that the presence of a functional nuclear targeting sequence in the primary structure of fibroblast growth factor (FGF)-1 correlates with its activity as a mitogen, but not with its potential for inducing receptor tyrosine phosphorylation, suggesting the presence of a yet undefined function of FGF-1 as a nuclear protein. In the present study we have investigated the cytosolic and nuclear localization of exogenously added FGF-1. FGF-1-specific monoclonal antibodies were raised. By an extensive screening, highly specific antibody clones were isolated. For both BALB/c 3T3 and human umbilical vein endothelial (HUVE) cells, immunofluorescence studies performed with those clones delineated that during G1 stage of cell cycle, FGF-1 transits from cytosol to nucleus. This was followed by a shift to the perinuclear and juxtanuclear region just prior to the onset of S-phase in BALB/c 3T3 cells. Confocal microscopical examinations confirmed that the nuclear staining resides throughout the nuclear matrix with some enrichment at the envelope boundary and in the nucleoli. Immunoblot analysis of the fractionated BALB/c 3T3 cells that had been induced to proliferate by serum and pulsed with exogenous FGF-1 at various timings revealed that the incorporation of exogenous FGF-1 into cytosol took place constantly, whereas the nuclear translocation significantly increased after 5 h following stimulation of the quiescent cells. The cytosolic form of FGF-1 is indicated to be present in soluble cytosolic fraction rather than membrane-enveloped compartments, endosomes, by the microinjection of anti FGF-1 antibody to HUVE cells cultured in the presence of FGF-1. The data demonstrate that the exogenously added FGF-1 is constantly endocytosed and fractioned into the cytosol soluble compartment, whereas its nuclear localization is regulated at the nuclear translocation level and takes place preferably at late G1 phase of the cell cycle.

3T3 Cells↗
PubMed1994

Isolation and fluorescence in situ hybridization mapping of 60 cosmid clones on human chromosome 18.

We have mapped 60 new cosmids on the short and long arms of chromosome 18 either by R- or by DAPI-banding and simultaneous fluorescence in situ hybridization. These markers were isolated from hybrid MS126-21 made from a human-rodent hybrid cell line that retained human chromosome 18. Twenty-two of the cosmid probes map on the short arm, and 31 probes cluster in the distal half of the long arm between bands 18q21.1 and 18q23, while 7 other probes are mapped more proximal to the centromere around bands 18q11.1-q12.3. The technique of fluorescence in situ hybridization has proven to be a very efficient methodology for gene mapping. These 60 probes will be useful in the elucidation of genetic alterations associated with diseases such as tetrasomy 18p syndrome, 18q- syndromes, and colorectal cancer.

Animals↗
PubMed1994

How to diagnose polysulphide poisoning from tissue samples.

We carried out animal experiments to toxicologically verify polysulphide poisoning by analyzing tissue samples. A bathing agent containing calcium polysulphides was administered orally to rats, and then polysulphides and sulphide, the decomposed product of polysulphides, were analyzed by GC and GC/MS. The concentrations of polysulphides (mumol/ml or g) were found to be highest in blood (0.196), followed by the liver (0.051), the lungs (0.018) and kidneys (0.013), but were below the detection limit (0.005 mumol/g) in the other tissues tested. Sulphide was detected in all the tissue samples and was found to be highest in the blood (0.518 mumol/ml), this being 40 times higher than that required for fatal poisoning in the case of hydrogen sulphide. Polysulphide poisoning was considered to be confirmatively diagnosed by detecting and measuring polysuphides and supplementarily sulphide in body tissues, most pertinently in the blood. Two practical cases of suspected poisoning by polysulphides are briefly described.

Animals↗