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Biomedical subjects

T Hoshi

Publications and source records attributed to T Hoshi.

At least 19 recordsLinked to original sources
PubMed1992

A retrospective survey of delayed adverse reactions to ionic and nonionic contrast media.

A comparative survey of delayed adverse reactions (DARs) to ionic and nonionic contrast media (CM) was carried out. In Japan high osmolar CM have mostly been replaced by new low osmolar CM. Therefore, a retrospective survey was performed limited to inpatients who had received an enhanced CT examination in our hospital. The material consists of 715 consecutive cases given ionic CM (iothalamate and diatrizoate) and 902 given nonionic CM (iopamidol and iohexol). DARs were picked up based on descriptions in the medical record up to 5 days after the examination. Most DARs had occurred within two days after the examination. Overall DARs were noted in 36 cases (5.0%) of the ionic group, and 44 cases (4.9%) of the nonionic group. Skin rash as well as other symptoms revealed no significant difference in incidence between the ionic and the nonionic group. There were no significant associations with immediate reactions, allergy, previous adverse reactions to CM. One patient given an ionic CM developed hypotension (60 mmHg) after return to the ward. It should be emphasized that a delayed shock had been recorded.

Aged↗
PubMed1992

Prognostic significance of the PC10 index as a prospective assay for cervical cancer treated with radiation therapy alone.

The monoclonal antibody PC10 recognizes proliferating cell nuclear antigen (PCNA) in conventionally fixed and processed histologic materials. Formaldehyde-fixed and paraffin-embedded specimens taken from 194 patients with Stage III squamous cell carcinoma of the cervix treated with radiation therapy alone were investigated for PC10 positivity using immunohistochemical methods. A few squamous epithelial cells in the basal layer and the deepest zone of the prickle cell layer were positive for PC10. Cancer cells also were positive for PC10, showing a diffuse or granular nuclear staining pattern. The multiple logistic regression model analysis and the Kaplan-Meier method indicate that a strong correlation exists between the PC10 index and prognosis (P less than 0.001). Thus, the PC10 index may be a predictive indicator for the prognosis of patients with squamous cell carcinoma of the cervix treated with radiation therapy alone.

Adult↗
PubMed1992

Simulated weightlessness and bone metabolism: gravitational stimulation enhances insulin sensitivity.

The effect of simulated weightlessness on bone metabolism was investigated in skeletal unloading for 4 days. Skeletal unloading was designed using the model of hindlimb hang in rats. Skeletal unloading with hindlimb hang cased a significant decrease of alkaline phosphatase activity, deoxyribonucleic acid (DNA) content, and glucose consumption in the femoral diaphysis, but not in the calvaria. When femoral-diaphyseal tissues were cultured in the presence of insulin (10(-8) M), the hormone produced a significant increase of alkaline phosphatase activity and decrease of glucose consumption in the femoral-diaphyseal tissues obtained from normal rats. This hormonal effect was not seen in the femoral diaphysis, but in the calvaria, of rats with skeletal unloading. However, insulin effect was seen in the femoral diaphysis obtained at 3 days after the removal of skeletal unloading. Meanwhile, the presence of other bone-regulating factors (10(-8) M parathyroid hormone [1-34] and 10(-4) M zinc sulfate) revealed an appreciable effect on alkaline phosphatase activity in the femoral diaphysis from rats with skeletal unloading. These results suggest that gravitational stimulation can directly enhance a specific insulin sensitivity in the regulation of bone metabolism.

5'-Nucleotidase↗
PubMed1992

Purification of brush border membrane vesicles from rat renal cortex by size-exclusion chromatography.

Size-exclusion chromatography with controlled pore glass (CPG) was used in the further purification of renal brush border membrane vesicles (BBMV) isolated by the Ca precipitation method. The BBMV obtained had an almost spherical shape and their average diameter was about 95 nm in isotonic solution. The specific activities of alkaline phosphate and leucine aminopeptidase in the BBMV preparation were increased 18- and 17-fold, respectively, over those in the crude homogenate. The uptake of D-glucose by the purified BBMV in the presence of a sodium gradient reached 8.53 nmol/mg protein at 20 s. These results indicate that CPG chromatography is suitable procedure by which to obtain purified renal BBMV of homogenous size and with high specific marker enzyme activity for use in the study of membrane transport.

Animals↗
PubMed1992

Changes in vitamin A status following prolonged immobilization (simulated weightlessness).

A study was conducted to investigate the effects of a simulated weightlessness induced by chronic immobilization on vitamin A status. To simulate the stress condition of weightlessness, rats were suspended for 10 days in a special jacket to which metal chains were attached. Animals received a commercial stock diet. Control rats were pair-fed in reference to the suspended rats. As compared with the control, prolonged immobilization resulted in a decrease in body weight gain and an increase in adrenal weight occurred. In the suspended rats, serum concentrations of retinol and retinol-binding protein (RBP) declined. Hepatic retinyl palmitate content increased, and the hepatic retinol level was decreased. The prolonged immobilization led to significantly reduced retinyl palmitate levels in the testis and lung as well as lowered testicular retinol levels. The results suggest that the stress state induced by prolonged immobilization caused accumulation of hepatic retinyl palmitate, decreasing the serum retinol concentration and retinyl ester content in the extrahepatic tissues.

Adrenal Glands↗
PubMed1992

The liver in systemic lupus erythematosus: pathologic analysis of 52 cases and review of Japanese Autopsy Registry Data.

We present pathologic findings for 52 livers (51 autopsy specimens and one wedge biopsy specimen) from patients with systemic lupus erythematosus (SLE). Hepatic congestion was the most common disease (40 livers), followed by fatty liver (38), arteritis (11), cholestasis (nine), peliosis hepatis (six), chronic persistent hepatitis (six), nonspecific reactive hepatitis (five), cholangiolitis (four), nodular regenerative hyperplasia of the liver (three), and hemangioma (three). The data obtained here suggest that arteritis of the SLE liver is more common than has been recognized previously. One patient had hepatic infarction complications induced by arteritis. On the basis of the findings in the present study and a review of the literature, we suggest that hepatic infarction resulting from arteritis is rare in SLE. On the other hand, while occurrence of nodular regenerative hyperplasia of the liver in SLE patients has been considered to be rare, our findings suggest that it may be more common than has been recognized previously. Although congestion and cholestasis may be acute terminal illnesses, fatty change is considered to be specific to the SLE liver. Statistical analysis indicates that exposure to a large dosage of glucocorticoids is a significant factor in the etiology of severe fatty liver. In addition, our review of Japanese autopsy registry data for 1,468 patients with SLE indicates that the incidence of chronic liver diseases in SLE autopsy cases is as follows: chronic hepatitis, 2.4%; cirrhosis, 1.1%; and liver fibrosis, 0.8%.

Adolescent↗
PubMed1992

Analysis of the leukotriene D4 receptor in the granulation tissue of allergic inflammation in rats.

Leukotriene (LT) D4 receptor in the granulation tissue formed in the air pouch-type allergic inflammation model in rats was analyzed. Membrane preparation of the granulation tissue obtained 3-9 days after the antigen challenge has specific binding sites of [3H]LTD4. Scatchard analysis showed that the affinity (Kd) and the density (Bmax) were not changed among the granulation tissue obtained 3-9 days after the antigen challenge. The Kd value in the granulation tissue (0.90 +/- 0.12 nM) was close to that in the rat lung (1.00 +/- 0.24 nM) and the guinea pig lung (0.86 nM). On the other hand, Bmax (62 +/- 8 fmol/mg protein) in the granulation tissue was higher than that in the rat lung (21 +/- 4 fmol/mg protein) but was far less than that in the guinea pig lung (405 fmol/mg protein). LTC4 and LTE4 inhibited the binding of [3H]LTD4 to the membrane preparation of the granulation tissue in a concentration-dependent manner. IC50 of LTC4 and LTE4 were 1 x 10(-7) and 2 x 10(-7) M, respectively. A guanine nucleotide, guanyl-5'-yl-imido-diphosphate (GppNHp), reduced [3H]LTD4 binding to the membrane preparation of the granulation tissue suggesting that LTD4 receptors in the granulation tissue are associated with G proteins. These results indicate that LTD4 binding sites in the granulation tissue are high affinity receptors for LTD4. A possible role of LTD4 in the recurrence of allergic inflammation in the chronic phase is discussed.

Animals↗
PubMed1992

Properties of active magnesium flux across the small intestine of the guinea pig.

Steady-state net flux of Mg2+ was measured in everted preparations of guinea pig jejunum and ileum, and effects of anoxia, Na+ and Ca2+ concentration, ouabain, and Ca2+ channel blockers were examined. Uphill Mg2+ flux in the mucosal-to-serosal direction was seen in both intestinal segments, with the flux value being 1.5 times greater in the ileum than in the jejenum. The Mg2+ flux was 1.7 times greater than the net Ca2+ flux under the same experimental conditions. The Mg2+ flux was strongly dependent on oxygen and the presence of Na+ in the medium; both anoxia and total replacement of Na+ inhibited the flux by 90-100%. Also, ouabain added to the serosal side, and verapamil or D600 added to the mucosal side, inhibited the flux by about 90%. Inhibitory effects of both ouabain and Na(+)-free conditions were much greater for the Mg2+ flux than for the Ca2+ flux. A stepwise increase in Mg2+ concentration in a Na(+)-free mucosal solution caused a stepwise elevation of the mucosal negativity. The relative elevation of the evoked potential in response to Mg2+ concentration possessed saturable and linearly increasing components. Only the saturable component was found to be dependent on oxygen and sensitive to ouabain. Under the influence of ouabain and verapamil, the generation of the Mg(2+)-evoked potential was greatly inhibited. These findings suggest that Mg2+ is actively absorbed by the jejunum and ileum of the guinea pig, and that active transcellular transport involves a verapamil-sensitive entry step and Na(+)-dependent or ouabain-sensitive exit process which differs from Ca2+ extrusion mechanisms.

Animals↗
PubMed1992

[Relationship between health services for maternal and child health and working hours of public health nurses].

Based on the "Maternal and Child Health Service Act", public health centers and municipalities offer health education, health counseling, health examination, and home visits for district children and for their mothers. The relationship between the number of the MCH services offered and the working hours of public health nurses at the public health centers and the municipalities was analyzed. Data were taken by a survey in 1989, which was used for evaluating services provided to the children and their mothers in 1988. Questionnaires were sent to 23 health centers and their districts and 100 responses from 8 wards, 20 cities, 47 towns, and 25 villages were analyzed. When total working hours of the public health nurse for MCH are allocated to the four parts-planning, implementation, evaluation and training-86.7% of working hours are for implementation itself. The correlation coefficient between the total working hours of the public health nurse for MCH and the population, and the number of births per year, were significantly positive. A total of 107 hours were supplied for the infant child health examination per 100 births per year, for which 64% was for implementation itself. In the case of the health examination for three-year-old children, total working hours were 143 hours, for with 79% was for implementation itself. The number of mother-child handbooks issued, the number of health education classes and health counselings conducted, various health examinations performed, and home visits made were correlated significantly with the working hours of the public health nurse.

Child↗
PubMed1992

[Mode of membrane transport of amino acids--the kidney].

In the kidney, more than 99% of filtered free amino acids are reabsorbed by the proximal tubule. The brush border membrane of this segment is known to possess at least 5 independent amino acid carriers; neutral alpha-amino, basic, acidic, neutral beta-amino and imino acid carriers. Ionic interactions have been shown to be markedly different among these carriers. Characteristics of the interaction were outlined for each carrier. Basolateral membrane carriers have not been investigated extensively, but existence of neutral amino acid carrier (s) devoid of ionic interaction has been established. In addition, a Na+ plus K+ gradient-dependent transport has been identified for acidic amino acids and a Na+ exchange carrier has been suggested for basic amino acids. Also, asymmetric ionic interactions are suggested for luminal and basolateral membrane carriers for beta-amino acids. Proton-dependent carrier (s) for di- and tri-peptides has also been identified in the proximal tubule.

Amino Acids↗
PubMed1992

Expression of human milk fat globule-1 in carcinomas of the uterine cervix treated with radiation therapy alone.

Expression of human milk fat globule-1 (HMFG-1) and HMFG-2 in cancer cells was studied in 269 patients with stage III and IV uterine cervical carcinomas that were treated with radiation therapy alone. They consisted of 233 patients with squamous cell carcinomas and 36 with adenocarcinomas. Of 233 patients with squamous cell carcinomas, 33 were negative for HMFG-1, and the other 200 were positive for HMFG-1. The 5-year survival rate was 36.4% (12/33) in HMFG-1-negative cases and 52.0% (104/200) in HMFG-1-positive ones. Patients who were negative for HMFG-1 showed a somewhat poorer prognosis than those who were positive for HMFG-1. The local control rates of HMFG-1-negative and -positive patients with squamous cell carcinomas were 58.6% (17/29) and 75.3% (125/166), respectively. Patients who were negative for HMFG-1 tended to show a lower local control rate than those who were positive for HMFG-1. In the uterine cervix, about one third of cells, only in the basal layer of stratified squamous epithelium, were positive for HMFG-1. These findings suggest that expression of HMFG-1 in cancer cells may mean the radiosensitivity.

Adenocarcinoma↗
PubMed1992

MR imaging of chronic alcoholism.

We evaluated the brain lesions of patients with chronic alcoholism (n = 34) in comparison with age- and sex-matched controls (n = 40) by MR imaging. T1-weighted sagittal and axial images and T2-weighted axial images were obtained with a 0.5 T superconducting MR unit. Various brain measurements were then performed, and the presence of regions of abnormal signal intensity was also compared between the two groups. The brain measurements revealed significant cerebral atrophy (characterized by lateral and 3rd ventricular dilatation, and widening of the interhemispheric fissure) as well as significant cerebellar atrophy (represented by 4th ventricular dilatation) in the alcoholic group. These changes were more prominent in patients in their fifties and sixties than in those aged in the thirties and forties. Focal hypointense lesions were observed in 20.6% of the alcoholics and in 5% of the controls (p less than 0.01), while focal hyperintense lesions were observed in 61.8% of the alcoholics and in 20% of the controls (p less than 0.001). The severity of these MR findings correlated well with the age of the patients. These observations suggest that alcohol is an important promoter of brain aging.

Adult↗
PubMed1991

Simulated weightlessness and bone metabolism: impairment of glucose consumption in bone tissue.

The effect of simulated weightlessness on bone glucose consumption was investigated in skeletal unloading for up to 4 days. Skeletal unloading was designed using the model of hind-limb hang in rats. Femoral-diaphyseal fragments obtained from rats bred with skeletal unloading were cultured for 24 h at 37 degrees C in 5% CO2/95% air in Dulbecco's Modified Eagle Medium (high glucose, 4.5 g/dl). The consumption of medium glucose by bone tissues was significantly decreased by skeletal unloading for 2 and 4 days, while the production of lactic acid from bone tissues was not significantly altered. In addition, adenosine triphosphate (ATP) content in the cultured bone was significantly decreased by skeletal unloading. The presence of calcitonin (synthetic [Asu1,7] eel, 3 and 30 nM) fairly restored bone glucose consumption impaired by skeletal unloading. However, the effect of insulin (1 and 10 nM) on bone glucose consumption and ATP content was not seen in the bone tissues with skeletal unloading. These results suggest that the sensitivity of bone response for insulin action is reteriorated by skeletal unloading.

Adenosine Triphosphate↗
PubMed1991

Simulated weightlessness and bone metabolism: impairment of insulin effect on alkaline phosphatase activity in bone tissue.

The effect of simulated weightlessness on bone alkaline phosphatase was investigated after skeletal unloading for up to 4 days. The skeletal unloading was designed by using the model of hindlimb hang in rats. The femoral-diaphyseal fragments obtained from rats bred with skeletal unloading were cultured for 24 h at 37 degrees C in 5% CO2/95% air in Dulbecco's Modified Eagle Medium (high glucose). The bone alkaline and acid phosphatase activity were significantly decreased by skeletal unloading. When the bone tissue was cultured with synthetic [Asu1,7] eel calcitonin (3 and 30 nM), the hormone caused a significant increase of alkaline phosphatase activity in the bone tissues from rats with normal and skeletal-unloading. In culture with insulin (1.0 and 10 nM), skeletal unloading impaired the effect on insulin to increase bone alkaline phosphatase activity. Meanwhile, the culture with zinc sulfate (10 and 100 microM), which can increase bone protein synthesis, caused a remarkable elevation of alkaline phosphatase activity in the bone tissues form rats with normal and skeletal-unloading. Insulin (10 nM) did not alter the zinc effect. These findings suggest that the skeletal unloading with hindlimb hang causes the impairment of insulin's effect to increase alkaline phosphatase activity in the femoral diaphysis of rats, although the effects of calcitonin and zinc were not altered.

Alkaline Phosphatase↗
PubMed1991

Changes in hepatic metabolism through simulated weightlessness: decrease of glycogen and increase of lipids following prolonged immobilization in the rat.

The effect of simulated weightlessness on hepatic metabolisms of carbohydrates and lipids was investigated in rats that were chronically immobilized by means of a suspension harness. During the 10-day period of the suspension, the animals showed a substantial decrease in the hepatic glycogen content, whereas the content of hepatic total lipids was markedly elevated. Similar results were obtained when the "suspended" animals were provided with a regular amount of nutrients by a force-feeding procedure. In the suspended animals, hepatic parenchymal cells were filled with large fat droplets, and hepatic triglyceride contents were elevated. The prolonged immobilization led to a slight, but significant, increase in glucose-6-phosphatase activity in the liver, suggesting that an increased glycogen breakdown might have occurred in the suspended animals. However, it was unlikely that the increased amount of glucose produced by the glycogen breakdown was utilized as a substrate for the lipogenesis in the liver, because hepatic lipogenic enzyme activities were unaffected by the suspension. The results suggest that the hepatic lipids accumulate in animals exposed to a prolonged immobilization state, presumably due to a decreased lipolysis and/or a suppressed lipoprotein mobilization from the liver into the blood stream.

Adrenal Glands↗
PubMed1991

Simulated weightlessness and bone metabolism: evidence for direct gravitational effect and its related insulin action.

The effect of simulated weightlessness on bone metabolism was investigated in skeletal unloading for 4 days. Skeletal unloading was designed using the model of hind-limb hang in rats. In hypokinetic state, rats were fed while the right hind limb was weighed down and the left hind limb was unloaded (a state of weightlessness). Bone metabolism in normal rats did not vary significantly in the femoral diaphysis in right and left hind limb. Alkaline phosphatase activity and DNA content in the femoral diaphysis were not significantly altered by hypokinetic state without skeletal unloading, while the unloading caused an appreciable decrease in the enzyme activity and DNA content. However, femoral-diaphyseal zinc content and glucose consumption was significantly decreased by hypokinetic state with and without skeletal unloading. When femoral-diaphyseal tissues were cultured in the presence of insulin (10 nM), the hormone produced a significant increase of alkaline phosphatase activity and decrease of glucose consumption in the femoral-diaphyseal tissues obtained from normal and hypokinetic rats. This hormonal effect was not seen in bone tissues from hypokinetic rats with skeletal unloading. These results suggest that skeletal unloading-induced disorder of bone metabolism is directly related to gravitational effect and that gravitational stimulation may be involved in insulin action.

Alkaline Phosphatase↗
PubMed1991

Two types of inactivation in Shaker K+ channels: effects of alterations in the carboxy-terminal region.

Shaker potassium channels inactivate and recover from inactivation with multiple exponential components, suggesting the presence of multiple inactivation processes. We describe two different types of inactivation in Shaker potassium channels. N-type inactivation can occur as rapidly as a few milliseconds and has been shown to involve an intracellular region at the amino-terminal acting as a blocker of the pore. C-type inactivation is independent of voltage over a range of -25 to +50 mV. It does not require intact N-type inactivation, but is partially coupled to it. The kinetics of C-type inactivation are quite different for channels with different alternatively spliced carboxy-terminal regions. We have localized the differences in C-type inactivation between the ShB and ShA variants to a single amino acid in the sixth membrane-spanning region. N- and C-type inactivation occur by distinct molecular mechanisms.

Animals↗