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Biomedical subjects

M Yoshioka

Publications and source records attributed to M Yoshioka.

At least 109 records · Page 6Linked to original sources
PubMed2000

Evaluation of prognostic factors and PCNA expression for pulmonary metastatic tumors of colorectal carcinoma.

The present study was conducted to evaluate clinicopathologically 26 patients whose primary colorectal carcinoma and resulting pulmonary metastatic tumors had been resected, and to determine the relationship between tumor progress and prognosis by PCNA immunostaining. Patients with solitary pulmonary metastasis were found to have much better prognoses than those with multiple metastasis. There was no correlation between tumor size of pulmonary metastasis and prognosis. Survival rates of patients with disease-free intervals (DFIs) of 2 years or longer were higher than for those with DFIs of less than 2 years. Mean PCNA expression of pulmonary metastatic lesions was significantly higher than that of primary lesions. It was suggested that the higher PCNA expression stemming from the relation between depth of tumor invasion and PCNA expression was greater with tumor progress.

Aged↗
PubMed2000

Successful removal of a stone and an expandable metallic stent from the biliary tract of a patient with acute occlusive pyogenic cholangitis.

We removed a biliary stone and the metallic stent placed two years previously in a patient with benign biliary strictures. An 80-year-old woman who had been inplanted with an expandable metallic stent (EMS) to prevent obstruction by a large common bile duct stone about two years before as an emergency measure in another hospital, was afficted with acute occlusive pyogenic cholangitis (AOPC) and hospitalized in our hospital. After treating the AOPC, we successfully removed the EMS with a cholangioscope and normal biopsy forceps through the percutaneous transhepatic channel under fluoroscopy. The type of the EMS was Accufulex stent. To remove it was easier than expected. Once it started to unravel, it was removed from the common bile duct within a few minutes.

Acute Disease↗
PubMed2000

Involvement of apoptosis in the endotoxemic lesions of the liver and kidneys of piglets.

The involvement of apoptosis was evaluated in lesions of endotoxemic piglets. A single injection with E. coli O111:B4 lipopolysaccharide (LPS) induced foci of coagulative necrosis in the liver and kidneys. No significant change was observed in these organs at 1.5 hr after LPS injection, but at 6 hr, epithelial cells with chromatin condensation or fragmentation and apoptotic bodies were visible. Foci of coagulative necrosis were formed within 24 hr after LPS inoculation. In and adjacent to the necrotic foci, dead hepatocytes with nuclear condensation or fragmentation were scattered. These dead cells were positively stained by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) methods. Electronmicroscopy revealed apoptotic cells with condensed or fragmented homogeneous nuclear chromatin, and necrotic cells with irregularly destroyed nuclei and cytoplasmic membranes. Apoptotic cell death were also observed in parietal cells of the stomach and lymphocytes in the lymphatic system. DNA ladders with approximately 200-bp multimers were observed in hepatic, renal and thymic samples prepared after 6 and 24 hr of LPS injection by agarose gel electrophoresis. These results suggest that apoptosis is involved in the pathology of swine endotoxemia.

Animals↗
PubMed2000

Detection of TT virus sequences in children with liver disease of unknown etiology.

DNA sequences of TT virus (TTV) in 55 serum samples taken from 20 children with liver disease of unknown etiology (16 with acute liver disease, 2 with fulminant hepatitis, and 2 with chronic liver disease) and from 35 healthy children as controls were examined by using the hemi-nested polymerase chain reaction (PCR). The PCR was carried out using the established primers (NG059, NG061, NG063) to amplify TTV DNA sequences. The sequences were detected in 6 of the 20 patients (30.0%) with liver disease and in 5 of the 35 healthy children (14.2%) by direct gel analysis. There was no significant difference between the prevalence of liver disease patients and controls. However, both patients with fulminant hepatitis and both patients with chronic hepatitis had TTV DNA sequences. Four of the six TTV isolates from liver disease patients were genotype 1a, whereas only one of the five TTV isolates from controls was genotype 1a. Although the study population was small, it is possible that genotype 1a of TTV might be more pathogenic than other genotypes in children.

Adolescent↗
PubMed2000

[A case of ruptured distal aortic arch aneurysm with bronchiolitis obliterans organizing pneumonia].

We report a case of histologically proved bronchiolitis obliterans organizing pneumonia (BOOP) associated with ruptured distal aortic arch aneurysm (DAAA) into the lung. A 63-years-old male with preoperative episode of hemosputum and hemoptysis was diagnosed DAAA. Preoperative computed tomographic scanning demonstrated that the aneurysm was surrounded with the structure of 2 layers of the enhanced high density external layer and the not enhanced low density internal layer. Combined resection of the left upper lobe and the aneurysm was performed safely because of marked adhesion between the lung and the aneurysm. Postoperative histological examination revealed that the perianeurysmal structure was due to BOOP.

Aneurysm, Ruptured↗
PubMed2000

[A case of rhabdomyolysis after open heart surgery in a child].

Rabdomyolysis usually occurs after trauma and release of myoglobin from the damaged muscle, i.e.; after ishchemic myopathy due to arterial occlusion or malignant hyperthermia. We encountered a pediatric case of rhabdomyolysis after Ross-Konnos' operation in an 8-yr-old girl with aortic regurgitation. After the first weaning from cardiopulmonary bypass (CPB), ventricular fibrillation occurred due to an insufficiency in coronary blood flow and CPB was resumed with rapid cooling of body temperature. The total CPB lasted for 5 hr 43 min. After the second weaning from CPB, myoglobinuria was found. Furthermore, blisters and abrasions appeared on her back and CPK levels were abnormally elevated (maximum 19,132 IU.l-1) without any elevation of body temperature in the postoperative course. Rhabdomyolysis due to intraoperative hypoperfusion was suspected and diuretics were administrated with a large amount of crystalloid to maintain urine output. The patient showed a good clinical course without acute renal failure. The course of this case suggests that rhabdomyolysis is one of rare complications of CPB and an early correct diagnosis of rhabdomyolysis and forced diuresis at an early stage are important to avoid acute renal failure.

Biomarkers↗
PubMed2000

[Juvenile parkinsonism with symmetrical hypoperfusion in the cerebellum--a case report].

We report a 24-year-old female presenting levodopa-responsive juvenile parkinsonism with symmetrical hypoperfusion in the cerebellum. At the age of 21, she noticed difficulty in brushing her teeth and writing with the right hand. She developed resting tremor in the right hand. These symptoms were dramatically relieved by levodopa. One year prior to the admission, she noticed dystonia and drug-induced motor fluctuations and her symptoms became worse. Neurological examinations disclosed resting and postural tremor in both hands and the right leg. Bradykinesia and cogwheel rigidity were noted on the right side. Deep tendon reflexes were slightly increased on the right side, while Babinski sign was negative. Slight lateropulsion was observed without retropulsion. Sensory, autonomic and cerebellar disturbances were not observed. No abnormalities were found in parkins gene or in the genes of spinocerebellar ataxia (SCA) 1,2,3,6,7,8 and alpha-synuclein. Cranial CT scan and brain MRI were normal, but technetium-99m ethyl cysteinate dimer (ECD) single photon emission computed tomography (SPECT) showed symmetrical hypoperfusion in the cerebellum. Other 5 patients presenting juvenile parkinsonism and 10 aged-matched normal controls in our hospital did not show hypoperfusion in the cerebellum on ECD SPECT. Cerebellar blood flow has not been measured in the previously reported cases of juvenile parkinsonism. These results suggested that etiopathogenesis in this patient was different from that in previously reported cases.

Adult↗
PubMed1999

Characterization of endogenous serotonin-mediated regulation of dopamine release in the rat prefrontal cortex.

Endogenous serotonin (5-hydroxytryptamine, 5-HT)-mediated regulation of dopamine release in the rat prefrontal cortex was pharmacologically characterized using in vivo microdialysis. To increase synaptic 5-HT availability, a selective 5-HT uptake inhibitor fluoxetine was applied via the dialysis probe. Local perfusion of fluoxetine (30 and 100 microM) increased dopamine levels in a concentration-dependent manner. The fluoxetine (100 microM)-induced increases in dopamine release were abolished by pretreatment with the 5-HT(1B/1D) receptor antagonist GR 127935 (N-[4-methoxy-3-(4-methyl-1-piperazinyl)phenyl]-2'-methyl-4'-(5- methyl-1,2,4-oxadiazol-3-yl)-[1,1-biphenyl]-4-carboxamide] ) (10 and 100 microM). The facilitation of dopamine release was also prevented by selective inactivation of the mRNA encoding 5-HT(6) receptors using antisense oligonucleotides techniques. These findings suggest that not only 5-HT(1B) receptors but also 5-HT(6) receptors are associated with the endogenous 5-HT-mediated facilitation of dopamine release. In other words, 5-HT(6) receptors may play, in part, a significant role in the functional interaction between the dopaminergic and serotonergic neuronal system in the rat prefrontal cortex.

Animals↗
PubMed1999

Arcadlin is a neural activity-regulated cadherin involved in long term potentiation.

Neural activity results in long term changes that underlie synaptic plasticity. To examine the molecular basis of activity-dependent plasticity, we have used differential cloning techniques to identify genes that are rapidly induced in brain neurons by synaptic activity. Here, we identify a novel cadherin molecule Arcadlin (activity-regulated cadherin-like protein). arcadlin mRNA is rapidly and transiently induced in hippocampal granule cells by seizures and by N-methyl-D-aspartate-dependent synaptic activity in long term potentiation. The extracellular domain of Arcadlin is most homologous to protocadherin-8; however, the cytoplasmic region is distinct from that of any cadherin family member. Arcadlin protein is expressed at the synapses and shows a homophilic binding activity in a Ca2+-dependent manner. Furthermore, application of Arcadlin antibody reduces excitatory postsynaptic potential amplitude and blocks long term potentiation in hippocampal slices. Its close homology with cadherins, its rapid inducibility by neural activity, and its involvement in synaptic transmission suggest that Arcadlin may play an important role in activity-induced synaptic reorganization underlying long term memory.

Amino Acid Sequence↗
PubMed1999

Glutathione S-transferase (GST) M1, T1, P1, N-acetyltransferase (NAT) 1 and 2 genetic polymorphisms and susceptibility to colorectal cancer.

A case-control study was carried out to examine the relation between genetic polymorphisms of five genes, cigarette smoking and colorectal cancer risk. We collected blood samples from 106 colorectal cancer patients and 100 healthy persons, then analyzed them to identify genotypes for glutathione S-transferase (GST) M1, T1, P1, N-acetyltransferase (NAT) 1 and 2 by the PCR method. We also collected smoking history data from all participants by questionnaire. From statistical evaluation on various combinations of genotypes, we observed that the cancer risk of those who have both GSTM1 present genotype and GSTP1 Adenine/Adenine homozygous genotype was significantly less than those who have other combinations of genotypes for two genes. For other combinations of genes, there was no significant association between genotype and cancer risk. There was also no significant association between amount of cigarette smoking and the cancer risk. These findings suggest that it is valuable to study cancer risk when examining genotypes of more than two genes at the same time. For further study, we need to collect more samples to increase statistical reliability, and besides cigarette smoking, include the nutrition data as an environmental factor.

Arylamine N-Acetyltransferase↗
PubMed1999

Effects of an interleukin-1beta analogue [Lys-D-Pro-Thr], on incomplete cerebral ischemia-induced inhibition of long-term potentiation in rat hippocampal neurons in vivo.

Although interleukin-1beta (IL-1beta) has recently been implicated in neuronal cell death in vitro and in vivo after global forebrain ischemia, the role of IL-1beta in the functional injuries, i.e. impairment of synaptic transmission, after cerebral ischemia that does not cause neuronal death in the nervous system remains unknown. To address this question, we investigated the effect of short-term incomplete ischemia without apparent neural death on hippocampal long-term potentiation (LTP) in anesthetized rats, and examined the possible role of IL-1beta as an intermediary in this effect. Short-term incomplete cerebral ischemia (10 min) was induced in halothane-anesthetized rats by bilaterally clamping the common carotid arteries. Four days after ischemia, functional injuries in neuronal transmission in the hippocampal formation were observed without significant changes in pathological studies such as neuronal cell death. The LTP elicited in both Shaffer-CA1 synapses and perforant path-dentate gyrus synapses was significantly inhibited by the short-term incomplete ischemia. This inhibition of LTP was blocked by IL-1beta tripeptide antagonist (Lys-D-Pro-Thr), suggesting that the inhibitory effect of mild ischemia on synaptic potentials and LTP may be mediated by the generation of IL-1beta. These findings have important implications for the role of IL-1beta in not only neuronal cell death but also functional injuries without cell loss, perhaps elicited by transient cerebral ischemia.

Anesthesia↗
PubMed1999

Effects of experimental hypercapnia on hippocampal long-term potentiation in anesthetized rats.

The effects of hypercapnia, which has been reported to impair consciousness, on the long-term potentiation of the population spike in the CA1 pyramidal cell of the hippocampus in anesthetized rats were studied. Experimental hypercapnemia was induced by inspired 13% CO2 with 21% O2. Arterial blood gas analysis after 80 min inspired 13% CO2 showed pH 7.08+/-0.05, PCO2 = 104.09+/-12.86 mmHg, PO2 = 90.71+/-18.89 mmHg, BE -4.64+/-2.97 (mean +/- SD, n = 18). Inspired 13% CO2 reduced the amplitude of the population spike to 50% of the baseline. After delivery of tetanic stimulation (400 Hz, five bursts of eight pulses, inter-burst interval 1 s) population spike height was enhanced to pre-tetanic levels. Withdrawal of inspired CO2 unmasked an increase in population spike amplitude. These findings suggest that acute retention of carbon dioxide, which is designated as pure hypercapnemia without hypoxemia, may suppress hippocampal synaptic transmission but not its plasticity.

Anesthesia↗
PubMed1999

Gender-specific frequency of background somatic mutations at the hypoxanthine phosphoribosyltransferase locus in cord blood T lymphocytes from preterm newborns.

Limited information is available regarding the frequency, spectrum, and clinical relevance of somatic mutations in the developing fetus. The goal of this study was to determine somatic mutant frequencies (Mfs) at the hypoxanthine phosphoribosyltransferase (HPRT) reporter gene in cord blood T lymphocytes from preterm infants to gain insight into in utero mutational events. Mf determinations were made by using the HPRT T cell cloning assay on cord blood samples from 52 preterm infants. Natural logarithm Mfs (lnMfs) from preterm infants were compared with results from our database for full-term infants. Our analysis revealed higher lnMfs in cord blood T lymphocytes from preterm compared with full-term infants (P = 0.008). In addition, preterm females had significantly higher lnMfs compared with full-term females (P < 0.001), whereas preterm males were found to have significantly lower lnMfs than preterm females (P = 0.005). Regression analyses also demonstrate a significant relationship between lnMf and gestational age for preterm females that does not exist for preterm males. These results demonstrate the gender-specific association between Mf and age in humans.

Female↗
PubMed1999

Detection of a novel DNA virus (TTV) sequence in peripheral blood mononuclear cells.

DNA sequences of a novel DNA virus (TTV) were examined in 81 peripheral blood mononuclear cell (PBMC) DNA samples from 48 children and 33 adults, 22 cord blood mononuclear cells (CBMC) DNA samples, and 7 autopsy liver tissue DNA samples by a hemi-nested polymerase chain reaction (PCR). The PCR was carried out using the published primers (NG059, NG061, NG063) to amplify TTV DNA sequences. The sequences were detected in 4 of 81 (5%) PBMC DNA samples, in none of 22 (0%) CBMC DNA samples, and in 2 of 7 (29%) liver tissue DNA samples by direct gel analysis. The PCR-amplified products were confirmed by direct sequencing. The sequencing showed considerable diversities, with differences of 0-55% in 6 TTV isolates, compared with the prototype sequence of TTV. These results suggest that TTV is a ubiquitous virus that produces asymptomatic infection in a large proportion of the general population without transfusion of blood-derived products. To our knowledge, this is the first report describing the detection of TTV DNA sequences in PBMCs.

Adult↗
PubMed1999

Biological functions of recombinant bovine interleukin 6 expressed in a baculovirus system.

The cDNA encoding bovine interleukin 6 (IL-6) was obtained from messenger RNA extracted from lipopolysaccharide-stimulated bovine Kupffer cells by the reverse transcription polymerase chain reaction (RT/PCR), and cloned into the baculovirus vector pVL 1392. Insect cells (Sf21AE derived from Spodoptera frugiperda) infected with the recombinant baculovirus secreted a large amount of 23.7 kD protein into the culture medium. This protein was capable of causing increased haptoglobin production and decreased albumin production in primary cultured bovine hepatocytes. The swine and human IL-6s were also able to decrease albumin production in bovine hepatocytes. This recombinant IL-6 did not stimulate the proliferation of 7TD1 cells (a murine IL-6-dependent cell line), whereas the recombinant swine IL-6 which was expressed in the same baculovirus system, and recombinant human IL-6 derived from Escherichia coli were each capable of stimulating proliferation of 7TD1 cells, respectively. This suggests a species restriction between bovine IL-6 and murine IL-6 dependent cell lines.

Acute-Phase Proteins↗
PubMed1999

Does neoadjuvant chemotherapy for carcinoma in the thoracic esophagus increase postoperative morbidity?

OBJECTIVES: The aims of this study were to examine whether neoadjuvant chemotherapy for a carcinoma in the thoracic esophagus increased the incidence of postoperative complications, and which clinicopathological factors may affect postoperative complications after esophagectomy. SUBJECTS AND METHODS: One hundred and forty-four patients who underwent neoadjuvant chemotherapy followed by esophagectomy for a carcinoma in the thoracic esophagus were reviewed in a retrospective study. Ninety-six patients received neoadjuvant chemotherapy and 48 did not. The postoperative complications were grouped either general complications (Complications A) or surgery-related complications (Complications B). Complications A consisted of pulmonary, cardiac, hepatic, renal, and neurological complications, and catheter sepsis. Complications B consisted of a gastrointestinal tract leak, gastrointestinal tract necrosis, an intrathoracic or intraabdominal abscess, hemorrhage, ileus, and vocal cord palsy. In these two categories of complications, 17 factors obtained from subjects were compared between patients with complications and those without by univariate and multivariate analyses. RESULTS: The patient characteristics did not differ between patients who received neoadjuvant chemotherapy and those without. The preoperative serum albumin level was higher in patients without complication than in those with complication in both two categories of complications (Complications A: p = 0.001, Complications B: p = 0.05). The proportion of patients who received neoadjuvant chemotherapy did not differ between patients with complication and those without complication in either category of complications. Multivariate analysis showed that preoperative Onodera's Prognostic Nutritional Index was the only factor reducing the incidence of complications A (p = 0.02, Odds ratio: 0.63). CONCLUSION: Neoadjuvant chemotherapy was well tolerated and was not associated with any increased morbidity or mortality after esophagectomy for a carcinoma in the thoracic esophagus.

Chemotherapy, Adjuvant↗