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Biomedical subjects

T Tsuda

Publications and source records attributed to T Tsuda.

At least 91 records · Page 5Linked to original sources
PubMed2000

Does smoking cessation improve mental health?

There is a possibility that cessation of smoking improves mental health, but there are no studies that have demonstrated this. A cohort study was performed for 1 year in 18 males who spontaneously stopped smoking (cessation group) and 173 who continued to smoke (smoking group). The mental health state was evaluated using the Japanese version of the 30-item General Health Questionnaire (GHQ-30) before the cessation of smoking and 6 months and 1 year after smoking cessation. Changes in the GHQ score were compared between the cessation and smoking groups. In order to control the effects of confounding factors, multiple regression analyses were performed using the GHQ score after 6 months and 1 year as dependent variables. The GHQ score in the cessation group significantly decreased 6 months and 1 year after smoking cessation (P < 0.04 and 0.01, respectively, by paired t-test). In the smoking group, the GHQ score slightly decreased. Repeated measure analysis of variance revealed that the decrease in the GHQ score in the cessation group was significantly larger than in the smoking group. Multiple regression analysis revealed significant effects of smoking cessation on mental health after controlling for other confounding factors. It can be concluded that smoking cessation may improve mental health.

Adult↗
PubMed2000

Kinetic basis for the donor nucleotide-sugar specificity of beta1, 4-N-acetylglucosaminyltransferase III.

The kinetic basis of the donor substrate specificity of beta1, 4-N-acetylglucosaminyltransferase III (GnT-III) was investigated using a purified recombinant enzyme. The enzyme also transfers GalNAc and Glc moieties from their respective UDP-sugars to an acceptor at rates of 0.1-0.2% of that for GlcNAc, but Gal is not transferred at a detectable rate. Kinetic analyses revealed that these inefficient transfers, which are associated with the specificity of the enzyme, are due to the much lower V(max) values, whereas the K(m) values for UDP-GalNAc and UDP-Glc differ only slightly from that for UDP-GlcNAc. It was also found that various other nucleotide-Glc derivatives bind to the enzyme with comparable affinities to those of UDP-GlcNAc and UDP-Glc, although the derivatives do not serve as glycosyl donors. Thus, GnT-III does not appear to distinguish UDP-GlcNAc from other structurally similar nucleotide-sugars by specific binding in the ground state. These findings suggest that the specificity of GnT-III toward the nucleotide-sugar is determined during the catalytic process. This type of specificity may be efficient in preventing a possible mistransfer when other nucleotide-sugars are present in excess over the true donor.

Acetylgalactosamine↗
PubMed2000

Tc-99m PMT hepatobiliary scintigraphy in the differential diagnosis of extrahepatic metastases and hepatocellular carcinoma.

PURPOSE: The authors evaluated the utility of hepatobiliary scintigraphy for tissue characterization of extrahepatic metastases from hepatocellular carcinoma (HCC) using Tc-99m N-pyrydoxyl-5-methyltriptophane (Tc-99m PMT). METHODS: We examined 13 patients with HCC (29 extrahepatic metastases and 3 benign bone lesions) and 5 patients with other cancers (15 extrahepatic metastases). Thirty minutes to 6 hours after intravenous administration of Tc-99m PMT, planar (all 47 lesions) and SPECT (42 lesions) images were obtained. Accumulation of Tc-99m PMT in the lesion was evaluated visually by comparing bone scintigraphy, computed tomography, magnetic resonance imaging, or all of these. RESULTS: Findings were positive in 12 of 13 patients with HCC and extrahepatic metastases (16 of 29 on planar imaging and 21 of 26 on SPECT). Findings in all three benign bone lesions and 15 metastatic lesions from non-HCC primary lesions were negative (0 of 18 on planar imaging, 0 of 16 on SPECT). There were no false-positive findings in these lesions. Lesion-by-lesion sensitivity, specificity, accuracy, and positive and negative predictive values were 55%, 100%, 72%, 100%, and 58% by planar imaging and 81%, 100%, 88%, 100%, and 76% by SPECT, respectively. CONCLUSIONS: Because of the high specificity and reasonable sensitivity, Tc-99m PMT appears to be useful for the differential diagnosis of extrahepatic metastases from HCC. SPECT improves the detectability of small or faint accumulation in metastases from HCC.

Aged↗
PubMed2000

Glycosylation of the gastrin-releasing peptide receptor and its effect on expression, G protein coupling, and receptor modulatory processes.

Many gastrointestinal G protein-coupled receptors are glycosylated; however, which potential glycosylation sites are actually glycosylated and their role in receptor transduction or receptor modulation (internalization, down-regulation, desensitization) is largely unknown. We used site-directed mutagenesis to address these issues with the gastrin-releasing peptide receptor (GRP-R). Each of the four potential glycosylation sites was mutated by converting the Asn (N) to Gln (Q). Transient expression in CHOP cells demonstrated that changing Asn(24) or Asn(191) inhibited GRP-R cell surface expression, whereas elimination of Asn(5) and Asn(20) had no effect. Using ligand cross-linking studies in stable mutants expressed in Balb 3T3 cells, all four potential extracellular sites were glycosylated with carbohydrate residues of approximately 13 kDa on Asn(5), 10 kDa on Asn(20), 5 kDa on Asn(24), and 9 kDa on Asn(191). Removal of three glycosylation sites (N5,20,24,Q mutant) did not alter receptor affinity or G protein coupling; therefore, it could be speculated that deglycosylation at Asn(191) might be responsible for the altered G protein coupling seen with complete enzymatic deglycosylation of the native receptor previously reported. Removal of any single glycosylation site did not interfere with GRP-R induced chronic desensitization or down-regulation. However, elimination of all three NH(2)-terminal sites (N5,20,24) markedly attenuated both processes, with no effect on acute homologous desensitization and with only a minimal alteration of GRP-R internalization, supporting the findings of other studies that suggest that chronic desensitization and down-regulation are functionally coupled, distinct from acute desensitization and distinct from internalization. These data show that separate and specific glycosylation sites are important for GRP-R trafficking to the cell surface, ligand binding, G protein coupling, chronic desensitization, and down-regulation.

3T3 Cells↗
PubMed2000

Comparison of intertypic antigenicity of Aino virus isolates by dot immunobinding assay using neutralizing monoclonal antibodies.

Neutralizing monoclonal antibodies (MAbs) against the Aino virus were prepared, and the neutralizing epitopes of the virus were defined by competitive binding assay. Seven continuous and overlapping neutralizing epitopes existed on the G1 glycoprotein of the Aino virus. Two antigenic domains were identified and were designated I and II, with domain II consisting of six epitopes. Dot immunobinding assays (DIAs) were performed with MAbs that recognized these seven neutralizing epitopes. DIAs were performed with 1 Australian strain and 21 isolates found in Japan between the years 1964 and 1995. The MAb response patterns of all isolates were divided into four groups. The Japanese isolates did not show large differences in antigenicity, but the antigenicity of the Australian strain collected in 1968 was significantly different from that of the Japanese strains; the Australian strain lacked reactivity to three epitopes and showed only low reactivity to one epitope.

Animals↗
PubMed2000

Bezafibrate increases prebeta 1-HDL at the expense of HDL2b in hypertriglyceridemia.

Prebeta1-high density lipoprotein (prebeta1-HDL), the initial acceptor of cell-derived cholesterol, can be generated from HDL(2) by hepatic lipase. Because bezafibrate elevates lipase activity, it may increase prebeta1-HDL at the expense of HDL(2). To answer this question, we determined the apolipoprotein A-I (apoA-I) distribution in 20 hypertriglyceridemics (triglycerides>2.26 mmol/L) and 20 sex-matched normolipidemics by native 2-dimensional gel electrophoresis. At baseline, prebeta1-HDL was 70% higher in hypertriglyceridemics than in normolipidemics (123.5+/-49.9 versus 72.5+/-34.1 mg/L apoA-I, P<0.01). Prebeta1-HDL was positively correlated with triglyceride (r=0.624, P<0.0001). A 4-week bezafibrate treatment (400 mg daily) increased prebeta1-HDL by 30% (160.2+/-64.5 mg/L apoA-I, P<0.05) but decreased HDL(2b) by 31% (from 188.8+/-94.9 to 129.3+/-78.7 mg/L apoA-I, P<0.05). Hepatic lipase activity increased by 24% (P<0.005). Prebeta1-HDL was generated either from ultracentrifugally isolated HDL(2) or from plasma during incubation with triglyceride lipase. In conclusion, bezafibrate increases prebeta1-HDL at the expense of HDL(2). We speculate that such an effect might partly contribute to the antiatherogenic action of bezafibrate.

Adult↗
PubMed2000

Detection of Akabane viral antigens in spontaneous lymphohistiocytic encephalomyelitis in cattle.

A 5-month-old Japanese black bull calf and twenty-seven 1-27-day-old calves exhibiting neurological signs between August and October 1998 were examined. The bull calf exhibited rapid breathing, fever, hypersensitivity, and ataxia and was euthanized 4 days after the onset of symptoms. The 27 calves primarily exhibited ataxia, and 15 had arthrogryposis. Histological examination of the bull calf revealed perivascular infiltraction by mononuclear cells, diffuse to multifocal gliosis, and neuronal necrosis in the brain and spinal cord. Multiple malacic foci were found in the midbrain in 5 cases. In contrast, in the 15 calves necropsied in October, there were fewer inflammatory changes, but there was neuronal cell loss in the ventral horn and a decrease in myelinated axons in the lateral and ventral funiculi. Immunohistochemical examination using a rabbit antiserum against Akabane virus strain OBE-1 revealed a large amount of viral antigen in the degenerating neurons and glial cells of the bull calf, mainly in the spinal gray matter. Small amounts of viral antigen in swollen axons and a few glial cells were found in 5 of 27 calves. Thirteen of the 27 calves had high neutralization antibody titers against the Akabane virus, whereas there was no significant antibody titer in most of the calves necropsied during August. The present study revealed that viral antigen detection was very useful for the diagnosis of Akabane diseases in the 5-month-old bull calf that was suspected to be infected postnatally, while it had limited usefulness in the other young calves.

Animals↗
PubMed2000

[Achievement of causal inference in the social medicine in Japan].

As a condition to achieving an agreement of recognition on the causal relationship in medicine, we firstly explained Hume's problem and counterfactual model. We, however, emphasized that we believe in the existence of causality on medical issues in our daily lives. Therefore, we illustrated conditions when we usually believe in causality. On the other hand, we criticized two well-known key phrases, "lack of mechanism in epidemiology" and "black box in epidemiology", which have often been used in Japan for skeptic viewpoints against epidemiologic methods even if epidemiology is often used to elucidate a causal effect in medicine in the world. We emphasized that a priori determinations of levels for inference of mechanism is necessary. And, the level and feature of mechanism should be defined in concrete expressions. After explanation of these basic concepts, we mentioned a classic view on specific diseases and non-specific diseases which have not been sufficiently discussed enough yet in Japan. As an example, we used the statements in the Japanese Compensation Law for the Health Effect by Environmental Pollution. In Japan, the classification of these diseases has been confused with that between manifestational criteria of diseases and causal criteria of them. We described the basic concepts to illustrate the causal relationship between non-specific disease and its exposure by using attached figures. Actually, we cannot recognize disease occurrence as a specific disease for several reasons. We indicated that we can recognize the magnitude of effect by causal relationships in medicine as a quantitative continuous variable.

Causality↗
PubMed2000

Application of latex beads agglutination test for the detection of the antibody against virus-infection-associated (VIA) antigen of foot-and-mouth disease (FMD) virus.

Latex beads agglutination (LA) for the detection of the antibody against virus infection-associated (VIA) antigen of foot-and-mouth disease (FMD) virus was estimated using experimentally infected animals. The VIA antibody titer by the LA test were compared with the neutralization titer and the titer by agarose gel diffusion (AGD) test, which has been used as a standard method for VIA antibody titration. The latex beads were coated with VIA antigen in carbonate buffer solution (0.5 M, pH 9.6) for the test. The sensitivity of the LA test was clearly higher than that of the AGD test in the results for cattle and swine infected experimentally. The antibody was detected in the bovine serum obtained at the 13th week after inoculation by the LA but not by the AGD test. The LA test appears to be simple, rapid and sensitive for the detection of the antibody of FMD virus in the surveillance of FMD and the FMD quarantine of imported animals.

Animals↗
PubMed2000

A case of sarcoidosis presenting as multiple pulmonary nodules, nasopharyngeal and cerebellopontine tumors.

A 64-year-old woman presented with multiple pulmonary nodules, and after spontaneous regression of the pulmonary lesions in six months, nasopharyngeal and right cerebellopontine tumors developed. Noncaseous epithelioid cell granulomas were demonstrated histologically in both resected pulmonary and nasopharyngeal tumors. She complained of hearing loss and tinnitus probably due to the cerebellopontine tumors. Corticosteroid therapy resulted in the improvement of these symptoms and the gradual decrease of tumor size. Although histological probe of the cerebellopontine tumors was not diagnostic, this patient was finally diagnosed as having sarcoidosis, based on the clinicopathological features, including systemic granulomatous lesions, MRI findings, and good response to corticosteroid therapy. The diagnosis of sarcoidosis is sometimes difficult when its clinical manifestations are uncommon.

Cerebellar Diseases↗
PubMed2000

[Tracheal tube/laryngeal mask exchange to prevent coughing in lung volume reduction surgery].

We report the use of laryngeal mask airway (LMA) to facilitate smooth emergence from anesthesia in 3 patients who underwent lung volume reduction surgery (LVRS) for severely symptomatic emphysema. To prevent coughing during emergence we replaced the endotracheal tube with LMA while patient was still in deep anesthesia. Emergence was smooth without coughing in all three patients, and ventilation with facemask was not needed after removal of LMA. We believe this technique is safe and beneficial for anesthetic management of LVRS.

Aged↗
PubMed2000

Angiotensin converting enzyme insertion/deletion polymorphism is associated with plasma antigen levels of plasminogen activator inhibitor-1 in healthy Japanese population.

Plasminogen activator inhibitor-1 (PAI-1) has a central role in the regulation of the fibrinolytic enzyme system. An elevated plasma PAI-1 level is associated with thrombotic disorders. In vitro and in vivo studies indicate that the renin-angiotensin system is involved in the regulation of PAI-1. A 287-bp insertion/deletion (I/D) polymorphism in the gene-encoding angiotensin converting enzyme (ACE) is associated with cardiovascular disorders. We evaluated the association between the ACE I/D polymorphism and plasma PAI-1 antigen levels in 110 healthy Japanese male subjects. Subjects with the D-allele of the gene-encoding ACE had higher levels of PAI-1 (26.3 +/- 14.7 ng/ml, mean +/- standard deviation) compared with those without (21.0 +/- 12.0; P = 0.0491). A multiple linear regression model with independent variables (age, body-mass index, total cholesterol level, triglyceride level, ACE I/D genotype, and PAI-1 genotype due to a single guanine I/D polymorphism in the PAI-1 gene) demonstrated that the triglyceride level (P = 0.0059) and ACE I/D genotype (P = 0.0372) were independent predictors of plasma PAI-1 antigen levels in a subset of the subjects without diabetes mellitus that were not taking lipid-lowering drugs. These findings suggest that the ACE I/D polymorphism is a genetic factor for the regulation of plasma PAI-1 antigen levels in the healthy Japanese population.

Adult↗
PubMed2000

[A case of atopic myelitis].

A 35-year old woman was admitted to our hospital because of slowly increased numbness of lower truncus and the legs for 10 months. She showed atopic dermatitis on her nape and bilateral popliteal fossa, and signs and symptoms of anorexia nervosa, such as asitia, emaciation, and menopause. Neurologic examination revealed Lhermitte's sign, muscle weakness of bilateral hands, deep and superficial sensory disturbance below the Th 4 level of thoracic spinal cord, and increased tendon reflexes of four limbs. Laboratory data showed hyperIgEemia and high titer of mite antigen specific IgE in sera. Cervical MRI demonstrated abnormal intensity area located at the C6 to C7 segments (i.e. low intensity in T1 weighted images and high in T2). She also showed hypercalcemia and swelling of the parathyroid gland, and had been diagnosed primary hyperparathyroidism by scintigram of the parathyroid gland. We concluded that this case is thought to be atopic myelitis, which has been recently reported as acute myelitis associated with hyperIgEemia and atopic dermatitis proposed by Kira et al. (1997). The patient also had anorexia nervosa and primary hyperparathyroidism.

Adult↗
PubMed2000

[Misoprostol-induced pneumonitis].

A 76-year-old woman presented with non-productive cough and progressive dyspnea, and was admitted to Oita Medical University Hospital. Arterial blood gas values obtained on admission indicated severe hypoxemia. Chest roentgenograms and computed tomography disclosed diffuse interstitial infiltrates in both lungs. Transbronchial lung biopsy specimens demonstrated thickened alveolar walls with lymphocyte infiltration and swollen type II pneumocyte proliferation. Eosinophils were observed mainly around bronchioles. For approximately 6 months prior to hospitalization, the patient had been given misoprostol, sodium aurothiomalate, prednisolone, and loxoprofen sodium for the treatment of rheumatoid arthritis. Based on the clinical history and findings, drug-induced interstitial pneumonia was suspected. All medications were discontinued, and the patient was then placed on corticosteroids. After treatment, arterial blood gas values improved and the findings on chest roentgenograms cleared up. Positive lymphocyte stimulation tests and positive dermal reaction patch tests implicated misoprostol as an etiologic factor in the patient's interstitial pneumonia. High serum levels of KL-6 and cytokeratin subunit 19 fragment had been detected on admission. These values returned to normal after the interstitial infiltrates had disappeared. To our knowledge, this is the first reported case of misoprostol-induced interstitial pneumonia.

Aged↗
PubMed2000

Accumulation of common clonal T cells in multiple lesions of sarcoidosis.

BACKGROUND: T cells recognizing as yet unknown antigens (Ags) are considered to play an important role in the development and perpetuation of the disease process of sarcoidosis. Several studies have shown that T cells that bear a limited T-cell receptor (TCR) repertoire may play an important role in this disorder. However, regarding variable (V) gene repertoire usage, the results differ among various reports. One reason for such inconsistency may be due to the materials used in these studies. Most studies analyzed the T-cell repertoire in the sarcoid lung. However, clonal expansion of pulmonary T cells, probably due to the activation by inhaled exogenous Ags, was observed and such expansion may seriously influence the repertoire analysis. MATERIALS AND METHODS: Reverse transcriptase-polymerase chain reaction and subsequent single-strand conformation polymorphism analysis were used for the analysis of TCR repertoire. To exclude unrelated T-cell clones, we used intramuscular sarcoid nodules and/or lymph node (LN) sarcoid lesions as our materials. We also analyzed sarcoid lesions from different organs and then compared the results. RESULTS: T cells of the same clonality were found to exist in widely separated sites in intramuscular and LN sarcoid lesions in almost all Vbeta subfamilies. Identical T-cell clones were present in the sarcoid lesions from different organs in several Vbeta subfamilies. CONCLUSIONS: Some of the common T-cell clones in separated sites in intramuscular and LN sarcoid lesions and in sarcoid samples from different organs may recognize Ags that are related to the pathogenesis of sarcoidosis.

Adult↗
PubMed2000

[A case of acute quadriplegic myopathy].

A 22-year-old man developed unconsciousness, severe quadriplegia and muscle atrophy, and had markedly elevated serum creatine kinase levels after using the high-dose steroid and nondepolarizing neuromuscular blocking agents during the course of sepsis and DIC. On neurological examination, he was lethargic. The patient had generalized muscle weakness and wasting, and diminished deep tendon reflexes. He weakly responsed to painful stimuli on the legs. The motor nerve conduction study demonstrated decreased CMAP (compound muscle action potential) amplitudes. Motor and sensory nerve conduction velocities and their distal latencies were normal. Muscle biopsy revealed marked muscle fiber atrophy predominantly in type 2 fibers and numerous basophilic and a few necrotic fibers. Some atrophic fibers had decreased to absent myosin adenosine triphosphatase activity in their center. Accordingly, he was diagnosed as having acute quadriplegic myopathy (AQM), which has been reported mainly in Western countries. The mechanism of muscle fiber degradation in this myopathy is still unknown. On immunohistochemical analysis to our patient, enzyme activities of various proteases such as calpain, cathepsin B, and proteasomes were increased in the sarcoplasm, especially in the atrophic fibers. We suggest that lysosomal cathepsin, nonlysosomal calpain, and ATP-ubiquitin-proteasome proteolytic pathways participate in muscle fiber degradation in AQM.

Acute Disease↗