Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

At least 379 records · Page 21Linked to original sources

PubMed1994

Localization of mRNA for protein phosphatase 2A in the brain of adult rats.

The gene expression for alpha and beta isoforms of type 2A protein phosphatase (PP2A-alpha and -beta) in the adult rat brain was examined by in situ hybridization analysis. No marked difference in the gene expression was discerned between the two isoforms in large portions of brain, except for the thalami in which the expression level for the alpha isoform was similar to that in the cerebral neocortex whereas that for the beta was lower than that in the neocortex. The gene expression was observed intensely in the piriform cortex, the cerebellar Purkinje and granule cell layers, and the hippocampal pyramidal and dentate granule cell layers, and the locus ceruleus, whereas the moderate levels of its expression were observed in the olfactory mitral cells and the pontine nuclei. The cerebral neocortex expressed the mRNA moderately to weakly without any laminar patterns, whereas the expression level in the caudate-putamen was very low. This expression pattern is basically similar to that of PP2C reported previously, except for the plexus choroideus and ependyma having no significant expression for PP2A.

Animals↗

PubMed1994

Formulation of inactivated influenza vaccines for providing effective cross-protection by intranasal vaccination in mice.

Attempts were made to formulate an inactivated influenza vaccine to provide effective cross-protection by intranasal vaccination in mice. Mice were immunized with a nasal site-restricted volume of various HA vaccines (split-product virus vaccines), prepared from some of the H1N1 subtype viruses which circulated in humans from 1934 to 1986, together with cholera toxin B subunit (CTB) as an adjuvant. Four weeks later, they were challenged intranasally with a lethal dose of the earliest H1N1 virus strain, A/PR/8/34 (PR8) or the latest virus strain, A/Yamagata/120/86 (Yamagata/86). The adjuvant-combined vaccines, prepared from drift H1N1 viruses, A/Kumamoto/37/79 and A/Bangkok/10/83, provided a higher degree of cross-protection against a challenge with Yamagata/86 than with PR8. A booster with another drift virus vaccine given 4 weeks after the primary vaccination increased the protection against Yamagata/86; the effect was higher when mice were vaccinated with a later strain as the second antigen than when boosted with PR8. These results suggest that vaccination with a later virus strain followed by another later strain in a two-dose nasal vaccination regimen gives effective cross-protection against the current epidemic virus strains.

Administration, Intranasal↗

PubMed1994

Synergistic action of cholera toxin B subunit (and Escherichia coli heat-labile toxin B subunit) and a trace amount of cholera whole toxin as an adjuvant for nasal influenza vaccine.

Cholera toxin B subunit (CTB) and Escherichia coli heat-labile toxin (LTB) (2 micrograms), each supplemented with a trace amount of cholera toxin (CT) (0.02-20 ng), were examined for the adjuvant effect on antibody (Ab) response against influenza inactivated HA (haemagglutinin) vaccine in Balb/c mice. Each mouse received a primary intranasal (i.n.) inoculation of the vaccine (1.5 micrograms) and the CT-containing CTB and in 4 weeks a second i.n. inoculation of the vaccine alone. The primary inoculation of the vaccine with CTB alone did not induce either anti-HA IgA or IgG Ab response, or haemagglutination-inhibition Ab responses in the serum. The vaccine with less than 2 ng of CT also failed to induce Ab response. On the other hand, the vaccine with CT-containing CTB induced a high Ab response, which increased depending on the CT dose. Moreover, the second vaccine induced a response more than ten times higher than the primary one and the response increased depending on the CT dose. Similar enhancement was found in the local anti-HA IgA Ab response in the nasal wash. Such synergistic effects were observed also between LTB and CT. The amount of Ab produced by the synergism was considered to be enough to protect against virus infection. These results suggest that CTB (or LTB) containing a trace amount of CT (about 0.1%) can be used practically as a potent adjuvant for nasal vaccination of humans against influenza.

Adjuvants, Immunologic↗

PubMed1994

Escherichia coli heat-labile enterotoxin B subunits supplemented with a trace amount of the holotoxin as an adjuvant for nasal influenza vaccine.

Escherichia coli heat-labile enterotoxin B subunit (LTB) (2 micrograms), supplemented with a trace amount of the holotoxin (LT) (0.02-20 ng), was examined for the adjuvant effect on antibody (Ab) responses against influenza inactivated haemagglutinin (HA) vaccine in Balb/c mice. Each mouse received a primary intranasal (i.n.) inoculation with the vaccine (1.5 micrograms), prepared from PR8 (H1N1) virus, together with LT-containing LTB and in 4 weeks a second i.n. inoculation of the vaccine alone. The inoculation of the vaccine with the LT-containing LTB induced significantly high primary and secondary anti-HA IgA and IgG Ab responses in the nasal wash and the serum, while the vaccine with LTB or less than 2 ng of LT induced little response. The synergistic adjuvant effect was maximal in the concentration of LTB supplemented with 0.2-2 ng of LT. Under these conditions, the augmented IgA and IgG Ab responses, which are cross-protective to PR8 HA molecules, provided complete cross-protection against PR8 virus challenge in mice immunized with heterologous vaccine within the same subtype. These results suggest that LTB containing a trace amount of LT can be used as a potent adjuvant for nasal vaccination of humans against influenza.

Adjuvants, Immunologic↗

PubMed1994

Effects of cholera toxin adjuvant on IgE antibody response to orally or nasally administered ovalbumin.

Effects of cholera toxin B subunits supplemented with 0.1% cholera toxin (CTB*) on systemic IgE antibody responses to ovalbumin (OVA) were examined in BDFI (H-2b/d), Balb/c (H-2d) and C3H (H-2k) mice given OVA intragastrically or intranasally. Two successive doses of OVA intragastrically administered to Balb/c and C3H mice induced little IgE response and resulted in almost complete unresponsiveness to subsequent intraperitoneal challenge with OVA in Al(OH)3, while the intragastric administration to BDF1 mice induced high IgE response and resulted in abrogation of the unresponsiveness to the subsequent challenge. The intranasal administration of OVA induced little IgE response and suppressed response to the subsequent challenge in any strain of mice. On the other hand, two successive doses of intragastric or intranasal OVA together with CTB* enhanced IgE response in all three strains and the subsequent challenge with OVA in Al(OH)3 induced higher IgE responses. These results suggest that CTB* augments IgE response to OVA and abrogates the unresponsiveness when administered orally or intranasally into mice together with OVA, regardless of the H-2 haplotype of the mice.

Adjuvants, Immunologic↗

PubMed1994

PCR analysis of the Y chromosome long arm in azoospermic patients: evidence for a second locus required for spermatogenesis.

We analyzed DNA from 63 Japanese men with either azoospermia or severe oligospermia whose Y chromosomes were cytogenetically normal. A total of 16 loci were examined: 15 loci on the long arm between DYS7E and DYZ1, and the YRRM1 locus, a candidate gene for the azoospermic factor, AZF. One patient with a pericentric inversion of the Y chromosome was also included. We detected micro-deletions in ten individuals. The YRRM1 gene was involved in only three of them. The remaining seven patients showed deletion between DYS7C and DYS239 in common, indicating the presence of at least one additional gene, deletion of which causes azoospermia.

Base Sequence↗

PubMed1994

Characterization of multiple molecular forms of Mg(2+)-dependent protein phosphatase from Saccharomyces cerevisiae.

Three molecular species of Mg(2+)-dependent protein phosphatase (MPPs-1, -2, and -3) were isolated by DEAE cellulose column chromatography and gel filtration from an extract of Saccharomyces cerevisiae. MPP-1 was further purified 150-fold by chromatography using thio-phosphorylated myosin light chain-agarose. MPPs-1, -2, and -3 were distinct from the major acid and alkaline phosphatases, and their activities were not affected by okadaic acid, microcystin-LR or Ca2+, and calmodulin, resembling the enzymatic properties of type 2C protein phosphatase of mammalian cells. The apparent molecular masses of MPPs-1, -2, and -3 on gel filtration were 53, 112, and 128 kDa, respectively. It was demonstrated that MPP-1 is a globular protein of 53-55 kDa and that MPPs-2 and -3 are oligomeric proteins that dissociate upon sucrose density gradient centrifugation, generating catalytic proteins of about 50 kDa. Since the substrate specificities of MPPs-1, -2, and -3 differed from each other both before and after sucrose density gradient centrifugation, it was suggested that the catalytic proteins of these three enzymes are distinct molecular species.

Chromatography, DEAE-Cellulose↗

PubMed1994

Magnetic resonance imaging of bone marrow changes after irradiation.

RATIONALE AND OBJECTIVES: Signal changes of irradiated bone marrow are thought to represent fatty change. However, more recent studies have indicated that other factors may contribute to these signal changes. We performed animal studies to investigate magnetic resonance (MR) signal change factors in correlation with histologic findings. MATERIALS AND METHODS: Forty-two male Wistar rats were given single doses (3, 8, and 20 Gy) of irradiation. Magnetic resonance imaging (1.5 T) was performed using spin-echo technique. RESULTS: In the acute phase (days 1-3), the T1 time was prolonged, probably secondary to decreased cellularity and edema. After this phase, the irradiated marrow showed marked T1 and T2 shortening that correlated with hemorrhage. In the chronic phase (after day 10), fatty replacement, fibrosis, and regeneration were observed. T2 times were stable in spite of regeneration because of the susceptibility effect of hemosiderin. CONCLUSION: The MR signal changes of irradiated marrow reflect not only fatty replacement, but hemorrhage as well.

Animals↗

PubMed1994

An image analyzing system for interstitial lung abnormalities in chest radiography. Detection and classification by Laplacian-Gaussian filtering and linear opacity judgment.

RATIONALE AND OBJECTIVES: The effectiveness of a computerized analysis system to detect and characterize interstitial lung abnormalities seen on chest radiographs was evaluated. This method included a process of four-directional Laplacian-Gaussian filtering and a process of linear opacity judgement. For quantitative analysis of interstitial opacities, the radiographic index, which is the percentage of opacity areas in a region of interest, was obtained and evaluated in the images. These opacities represented interstitial lung abnormalities. METHODS: Two regions of interest were selected in each right lung of 50 patients with normal lung parenchyma and 50 patients with diffuse interstitial lung abnormalities, confirmed with high-resolution computed tomography. These regions of interest were processed by our computerized analysis system. RESULTS: Abnormal lungs were well differentiated from normal lungs by the radiographic indices obtained from the images filtered by four-directional Laplacian-Gaussian filters and from those processed by linear opacity judgement. However, honeycomb lesions and other interstitial abnormalities (interstitial changes other than honeycombing) were differentiated from each other only by the radiographic indices obtained from the image processed by linear opacity judgment (P < .05). DISCUSSION: These results indicate that this system is useful for the detection and characterization of interstitial lung abnormalities.

Female↗

PubMed1994

Identification of autoantibodies to a pancreatic antigen in patients with idiopathic chronic pancreatitis and Sjögren's syndrome.

A serum autoantibody to a pancreatic antigen was identified in patients with idiopathic chronic pancreatitis and Sjögren's syndrome by radioimmunoassay and Western immunoblotting. Antigen from porcine and human pancreas extracts was partially purified using a monoclonal antibody, SP3-1, which recognizes the antigen in duct cells of various exocrine organs. Solid phase radioimmunoassay of the pancreatic antigen showed a positive result in 6 of 20 patients with idiopathic chronic pancreatitis (30%), 3 of 11 patients with Sjögren's syndrome (27%), and 1 of 15 patients with alcoholic chronic pancreatitis (7%). Among seven patients with stone-related chronic pancreatitis, six patients with autoimmune thyroiditis, and 14 normal controls, none showed evidence of autoantibodies to the pancreatic antigen. Western immunoblotting showed that serum antibody commonly reacted with a 60-kD molecule of either porcine or human pancreatic antigen, with which SP3-1 also reacted. These results show the existence of the autoantibodies to pancreas, especially to an antigen expressed in ductal cells of exocrine glands, in idiopathic chronic pancreatitis and Sjögren's syndrome, and suggest the possibility of an autoimmune mechanism in the pathogenesis of idiopathic chronic pancreatitis.

Animals↗

PubMed1994

Structure, function and brain localization of neurotransmitter transporters.

We studied four different cDNAs encoding GABA transporters and three different cDNAs encoding glycine transporters in mouse and rat brains. A genomic clone of two of the glycine transporters (GLYT1a and GLYT1b) revealed that they derive from differential splicing of a single gene. The third glycine transporter (GLYT2) is encoded by a separate gene. Antibodies were raised against seven of these neurotransmitter transporters and their cytochemical localization in the mouse brain was studied. In general, we observed a deviation from the classical separation of neuronal and glial transporters. It seems that each of the neurotransmitter transporters is present in specific places in the brain and is expressed in a different way in very specific areas. For example, the GABA transporter GAT4, which also transports beta-alanine, was localized to neurons. However, GAT1, which is specific for GABA, was localized not only to neurons but also to glial cells. The recently discovered glycine transporter GLYT2 was of particular interest because of its deviation from the general structure by a very extended N terminus containing multiple potential phosphorylation sites. Western analysis and immunocytochemistry in frozen sections of mouse brain demonstrated a clear caudal-rostral gradient of GLYT2 distribution, with massive accumulation in the spinal cord and brainstem and less in the cerebellum. Its distribution is typically neuronal and it is present in processes with varicosities. A correlation as observed between the pattern we obtained and that observed previously from strychnine binding studies. The results indicate that GLYT2 is involved in the termination of glycine neurotransmission at the classical inhibitory system in the hindbrain. The availability of four different GABA transporters made it possible to look for specific binding sites upon the neurotransmitter transporters. An extensive program of site-directed mutagenesis led us to identify a potential neurotransmitter binding site on the GABA transporters.

Amino Acid Sequence↗

PubMed1994

[A case-control study on the risk factors of sudden death. An analysis of 44 cases in a company by health care records].

A case-control study was conducted on sudden deaths in a company having about 40,000 workers to determine the risk factors of sudden death. Sudden death was defined as internal death within 24 hours from the onset of the event. Two controls whose sex and age were matched with a case were selected from the employees of the company. The risk factors studied were age, sex, obesity, blood pressure, serum glucose, total cholesterol, triglyceride, uric acid, urinary, protein, urinary sugar, electrocardiographic (ECG) findings, diabetes mellitus, smoking history and drinking history. These data were collected from the latest health care record including health examinations performed annually in the company. t test, U test and Fisher's test were applied to each of the variables. Multiple logistic regression analysis and canonical discriminant analysis were applied, using mean systolic blood pressure for 5 years, body mass index (BMI), abnormal Q wave on ECG, and serum glucose as explanatory variables. From 1984 to 1990 44 sudden death cases composed of 42 males and two females were identified. The age-specific mortality rate increased exponentially with age with a peak at the sixth decade. The most frequent cause of sudden death was heart disease (77%) followed by cerebrovascular disease (18%). Statistical analysis showed that significant risk factors were high blood pressure, low BMI, diabetes mellitus, and ST-T change on ECG.

Adult↗

PubMed1994

Genetic origin analysis of hydatidiform mole and non-molar abortion using the polymerase chain reaction method.

OBJECTIVES: The study attempts to determine the genetic origin of hydatidiform mole and non-molar abortion using the polymerase chain reaction (PCR) method, and reevaluates this method as a possible diagnostic tool for hydatidiform mole. MATERIAL AND METHODS: A total of 71 cases which consists of 21 complete hydatidiform moles, three partial hydatidiform moles, and 47 non-molar abortions were investigated. The genetic origin was analyzed by the PCR method applied to the variable number of tandem repeat regions of the Apolipoprotein B gene, the human type-II collagen gene, and the probe YNZ22. Chromosomal analysis was also performed. RESULTS: Genetic origin was determined in 58 out of 71 cases (83.1%). All of the complete hydatidiform moles were androgenic, having only paternal alleles. On the other hand, all the partial hydatidiform moles and non-molar abortions revealed clear biparental contribution. Besides triploid partial hydatidiform moles, one non-molar abortion showed two paternal and one maternal complements. CONCLUSIONS: Our results were compatible with the classical theory of androgenic origin of complete hydatidiform mole; only complete hydatidiform mole is caused by androgenesis. We also found no complete hydatidiform mole of biparental origin. In conclusion, this PCR method brings a new aspect of genetic origin in the diagnosis of trophoblastic disease. It would be interesting to explore how morphologic subgrouping and genetic origin relate to the prognosis of trophoblastic disease.

Abortion, Spontaneous↗

PubMed1994

[Characterization of cell lines from metastatic maxillary cancer].

Two cell lines were established one from a primary site (OKK-TKp) and the other from a metastatic lymph node (OKK-TKm), from a maxillary squamous cell carcinoma (in the same patient). These cell lines were characterized with regard to morphology, chromosome numbers, tumorigenicity, growth kinetics, expression of tumor markers, sensitivity to immunological effector cells and anticancer agents. The two cell lines had the same modal chromosome number of 69, and formed tumors in nude mice. The median doubling time of OKK-TKp was 14.6 hrs and that of OKK-TKm was 24.3 hrs. Immunohistochemistry showed transferrin receptor (TfR), Ki-67, and epidermal growth factor receptor (EGFR) in OKK-TKm, but less or none in OKK-TKp. OKK-TKm was more sensitive to lysis by lymphokine-activated killer cells (LAK) on a 4-h 51Cr release assay, but was less sensitive to anticancer agents (CDDP, CBDCA) in modified MTT assay. We are convinced that these results are of value for understanding the mechanism of metastasis.

Aged↗

PubMed1994

Alteration in growth regulation of hepatocytes in primary culture obtained from cirrhotic rat: poor response to transforming growth factor-beta 1 and interferons.

Cell growth appears to be controlled by positive and negative cell growth regulation. Little is known about the growth regulation of hepatocytes in the cirrhotic liver. Clarifying the responses of hepatocytes obtained from cirrhotic liver to various growth factors and growth inhibitory factors might aid understanding of alterations in growth regulation of the hepatocytes in the cirrhotic liver. We investigated the effects of hepatocyte growth factor, epidermal growth factor, heparin-binding epidermal growth factor-like growth factor, transforming growth factor-beta 1, interferon-alpha and interferon-gamma on the DNA synthesis of hepatocytes from cirrhotic and normal rats in primary culture. Cirrhosis was induced in male Sprague-Dawley rats by means of oral administration of 0.05% thioacetamide in drinking water for 4 mo. Hepatocytes were isolated by means of an in situ perfusion method, and DNA synthesis was assessed from the amount of DNA-incorporated [3H]thymidine. Stimulation of the DNA synthesis of hepatocytes by hepatocyte growth factor, epidermal growth factor and heparin-binding epidermal growth factor-like growth factor was not different between normal and cirrhotic rat liver. Transforming growth factor-beta 1 inhibited the DNA synthesis of hepatocytes in both. However, the concentration of transforming growth factor-beta 1 giving a 50% inhibition of DNA synthesis was about two times higher in cirrhotic hepatocytes (0.11 ng/ml) than in normal hepatocytes (0.06 ng/ml). In cirrhotic hepatocytes, the expression of transforming growth factor-beta type II receptor gene was about 50% of that in normal hepatocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Disorder in ultrastructure of basement membrane and mechanical junction in human esophageal cancer.

The ultrastructure and clinical significance of the basement membrane (BM) are still unclear in esophageal cancer. In this report, we examined the ultrastructure of the BM and microstructures related intercellular adhesion in squamous cell carcinoma of human esophagus using a transmission electron microscope, and investigated their clinical significance. BM was absent in 38% of the examined cases and the frequency or the presence of the microstructures of cancer cells of the infiltrating margin (CCIM) was negatively related to the presence of BM (BM-P); CCIM of BM-P tumors often had smaller number per cell of desmosomes and cytoplasmic processes. These results indicate that CCIM of BM-P tumor are in an 'inconvenient status' for tumor cells to form a firm group. In the intercellular space between CCIM and BM or surrounding stromal cells, all of the CCIM of BM-P tumors had hemidesmosomes, but not those of BM absent (BM-A) tumors. Though no statistical significant difference was found in our clinical observation between BM-P and BM-A tumors, the present study suggested that a considerable proportion of cancer cells have abnormal intercellular adhesiveness via a mechanical mechanism related to the presence or absence of BM.

Basement Membrane↗

PubMed1994

[An extended operation for scirrhous gastric cancer--its significance and procedure].

We have been performing an extended operation for scirrhous gastric cancer, namely left upper abdominal exenteration plus Appleby's method, and compared the prognosis among macroscopic subtype classifications. The surgical procedure of left upper abdominal exenteration plus Appleby's method is to resect the neighboring organs of the stomach in an en bloc fashion. It consists of total gastrectomy, partial pancreatectomy, splenectomy, transverse colectomy, cholecystectomy, resection of the left adrenal gland, and ligation and resection of the common hepatic artery. D4 lymph node dissection is carried out. Extended operations were performed for 45 cases of P0-1 scirrhous gastric cancer in 1983-1990. There were 25, 17 and 3 cases of giant fold type, erosive type and stenotic type scirrhous gastric cancers, respectively. Positive lymph node metastases were found in 64% of giant fold type cases and 82% of erosive type cases. In Po, T3-4 cases, cytology of intraoperative peritoneal lavage was positive in 27% of giant fold type cases and 50% of erosive type cases. Although there were no obvious macroscopic invasions found during the operative procedure, later histological study showed invasion to the left adrenal gland in 14% of giant fold type cases and 0% of erosive type cases, and invasion to the transverse colon in 21% of giant fold type cases and 15% of fold type and erosive type scirrhous gastric cancer according to the histological invasion of transverse colon were 25% in positive cases and 27% in negative cases (p = 0.27), 0% in positive cases and 27% in negative cases (p = 0.27), respectively. In giant fold type scirrhous gastric cancer, the extended operation is favorable. In erosive type scirrhous gastric cancer, peritoneal dissemination is observed with a high incidence. Therefore, prophylactic therapy is significant.

Adenocarcinoma, Scirrhous↗

PubMed1994

[Nippon Telegraph and Telephone Corporation workplace smoking control--a questionnaire survey of male NTT workers in the Tokyo area].

A survey of NTT workers regarding smoking control in their workplaces was conducted utilizing a questionnaire administered at the time of routine employee medical examinations. The questionnaire was self-administered and anonymous. Subjects were 1918 men, almost all who were involved in office work in the Tokyo area. Responses were obtained from 1872 (20's and 30's year of age 13.2%, 40's 68.1%, 50's 18.8%) after excluding 106 for incomplete responses. The results were as follows; 1. Of the subjects, 43.4% reported that smoking control was already in effect in their workplace. As for the method of smoking control, smoking restricted to specified places was the most common (31.1%). 2. Of smokers, only 9.8% approved of smoking control in their workplaces, 9.8% were opposed, and 80.1% of smokers reluctantly complied to smoking control in their workplaces. 3. About 60% of subjects, without distinguishing smoking habit, supported smoking restricted to specified areas as the method of smoking control. 4. Over 95% of smokers replied that they can successfully refrain from smoking in prohibited places. 5. For locations where they smoke, smokers listed employee lounge (91.5%), lavatory (83.7%), personal room (75.5%), at own desk (75.3%), reception room (72.7%) and conference room (64.3%). More than half of non-smokers replied that they disapprove of smoking in these places. These results suggest that smoking restricted to only specified places is most appropriate as the method of smoking control in the workplace. However differences exist between smokers and non-smokers as to appropriate designation of smoking areas and non-smoking areas.

Adult↗