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Biomedical subjects

T Shimada

Publications and source records attributed to T Shimada.

At least 667 records · Page 37Linked to original sources
PubMed1992

Three-dimensional architecture of pericytes with special reference to their topographical relationship to microvascular beds.

Microvascular beds and pericytes in the submandibular gland, thyroid gland and heart were studied by combined scanning electron microscopy and chemical digestion. The submandibular gland had a relatively loose network of blood capillaries, the thyroid gland possessed a close-meshed network of capillaries, and those in the myocardium ran parallel to the long axis of myocardial cells. The thyroid gland exhibited the largest numbers of pericytes. Three types of pericytes could be distinguished by their shape and localization. Type I pericytes, which were confined to true capillaries, had a fusiform or polygonal cell body, a few long, slender longitudinal processes (primary ones) and short, fine circumferential processes (secondary ones). Type II pericytes, which were found in the arterial side of myocardial capillaries, were characterized by large, circumferential band-like processes completely encircling the vessel. Type III pericytes, which were seen on the venous side of thyroid and myocardial capillaries, had a flattened cell body and short, irregular processes. Type II and III pericytes appear to show an intermediate or transitional form between smooth muscle cells and typical pericytes (Type I). Judging from the configuration of pericytes suggests that these are related to functions such as contraction as well as mechanical support.

Animals↗
PubMed1992

A successful therapy with plasma exchange for interstitial pneumonia of progressive systemic sclerosis.

A 47-year-old woman who was diagnosed as progressive systemic sclerosis (PSS) had acute and severe interstitial pneumonia. Based on the results of her chest roentgenogram, computed tomography, transbronchial lung biopsy (TBLB) and bronchoalveolar lavage (BAL), her interstitial pneumonia was considered to be atypical of PSS. Although she was treated with corticosteroid, methylprednisolone pulse therapy and immunosuppressive drug, the effect of these drugs was insufficient as treatment for the interstitial pneumonia. Therefore, plasma exchange was attempted. After plasma exchange was carried out for three days, her symptoms improved as well as the laboratory data and chest roentgenogram without any severe side effects. We recommend plasma exchange for interstitial pneumonia of PSS as an effective treatment.

Adrenal Cortex Hormones↗
PubMed1992

Airway responses to repeated exercises detected by krypton-81m in asthmatic children.

A repeated exercise program was used to test 7 asthmatic children for changes in ventilation. These changes were examined by continuously inhaled Krypton-81m and compared in subjects with positive and negative refractoriness, as defined by forced expiratory volume in 1 second (FEV1). Three of the seven patients showed significant refractoriness (% reduction in FEV1 > 50%). After the first exercise, they showed one or two ventilation defects which improved after the second exercise. The patient with incomplete refractoriness showed similar results. On the contrary, subjects without refractoriness showed several ventilation defects which fluctuated after the second or third exercise program. One defected area improved after the second exercise session, but deteriorated after the third; and another area deteriorated after the second exercise and improved after the third. It was concluded that approximately half of the patients were refractory in view of FEV1, but that they were all refractory in view of regional ventilation 81mKr images.

Acetylcholine↗
PubMed1992

[The relationship between fecal kinetics and body temperature in elderly people].

The relationship between fecal kinetics and body temperature was examined in elderly people. The subjects consisted of 34 hospitalized patients over 65 years of age (11 males aged 66-82 years, with a mean age of 70.3 years; and 23 females aged 65-84 years, with a mean age of 72.1 years). Then mean age of all subjects was 71.5 years. The subjects were divided into two groups: the non-constipation (NCP) group (patients who had been evacuating at least once daily) and the constipation (CP) group (patients who had not evacuated for 3 days or more). In the CP group, we analyzed the lowest and highest body temperature during two consecutive days (the day of evacuation and the previous day) and the lowest body temperature during another two days (the day of evacuation and the following day). In the NCP group, 3 consecutive days were selected at random for analyzing the lowest body temperature on the first day, the highest body temperature on the second day and the lowest body temperature on the third day. In the CP group, the body temperature before evacuation was 37.3 degrees C or more in 6 of the 28 patients (21.4%). In the NCP group, the highest body temperature before evacuation averaged 36.39 degrees C and the lowest body temperature after evacuation averaged 36.0 degrees C, with a temperature difference of 0.39 degrees C between the pre- and post-evacuation periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Presence of lower temperature-dependent antibody with low avidity to C100-3 (HCV) antigen in voluntary blood donors.

Serum samples with lower temperature-dependent antibody with low avidity to C100-3 (HCV) antigen were found in 0.19% of 23,197 voluntary blood donors at this blood center. They showed positive C100-3 antibody activity at 24 C but not at 37 C. The antibody activity bound to C100-3 antigen at lower temperature disappeared after incubation for 60 min at 37 C or treatment with 8 M urea. Other markers of hepatitis C virus infection, especially the presence of HCV-RNA were demonstrated in some of these serum samples and the importance of this phenomenon is discussed with regard to virus screening of blood donors for hepatitis C.

Antibody Affinity↗
PubMed1992

[Pulmonary distribution of 99mTc-technegas--a comparative study of radioactive inert gases].

99mTc-technegas (99mTc-gas), which consists of fine particles, is produced in carbon crucibles burned at 2500 degrees C. On this study, the particle size of 99mTc-gas was measured and the pulmonary distribution of 99mTc-gas was assessed in 28 patients with various pulmonary diseases. Most particles were 5-30 nm in diameter as determined by electron microscopy. In a clinical study, about 37 MBq of 99mTc-gas was inhaled three times during deep breathing in a sitting position. In a comparative study with radioactive inert gases (133Xe, 81mKr), 99mTc-gas showed a similar distribution to the inert gas in most patients, although some with obstructive disease showed hot spots in the lung fields. In patients with severe obstructive change, marked deposits of 99mTc-gas was noted in the central airways, but 99mTc-gas penetrated to the peripheral lung field. This result suggests that 99mTc-gas can be used to evaluate ventilatory function even in patients with chronic obstructive pulmonary diseases.

Gases↗
PubMed1992

Systolic and diastolic left ventricular dysfunction in middle-aged asymptomatic non-insulin-dependent diabetics.

Radionuclide ventriculographic studies were performed at rest and during exercise in 15 middle-aged asymptomatic patients with non-insulin-dependent diabetes mellitus (NIDDM) whose mean age was 58.7 +/- 10.5 years (mean +/- SD), and in 10 age- and sex-matched normal control subjects. The patients had neither clinical evidence of cardiovascular diseases nor obvious perfusion defects during maximal exercise testing with thallium-201 myocardial scintigraphy. The average left ventricular ejection fraction (LVEF) at rest was 69.1 +/- 5.3% in the diabetic patients and 65.6 +/- 4.2% in the control subjects, and during exercise, the average LVEFs were 68.3 +/- 6.9% and 72.1 +/- 5.0%, respectively. The changes in LVEF during exercise were -0.7 +/- 7.6% in the diabetic group and +6.5 +/- 2.6% in the control group (p < 0.01). However, the filling fraction during the first third of diastole at rest was significantly less in the diabetic group than in the control group (p < 0.05), the time to peak filling rate (TPF) was longer, and the TPF/R-R, normalized by the R-R interval and expressed as a percentage, was greater in the NIDDM patients than in the control subjects. There was close correlation between the abnormal response of LVEF to exercise and the reduced early diastolic filling in the diabetic patients. We concluded that 1) not only the response of LVEF to exercise but also the early left ventricular diastolic filling at rest are impaired in middle-aged asymptomatic NIDDM patients, and 2) some common factors could cause dysfunction of both the systolic and diastolic left ventricles in NIDDM patients, possibly latent global myocardial ischemia or metabolic myocardial disturbances.

Adult↗
PubMed1992

Mechanism of inhibitory effects of azelastine on smooth muscle contraction.

The mechanism of inhibitory effects of azelastine, an antiallergic and antiasthmatic agent, on depolarization- and alpha-1 adrenergic agonist-induced contractions of intact smooth muscle was studied. The effects of azelastine on membrane currents were determined in isolated guinea pig ileum smooth muscle cells with the whole-cell clamp technique; the effects on contraction were evaluated in receptor- and G-protein-coupled, alpha-toxin-permeabilized rabbit femoral artery and portal vein smooth muscle strips. Azelastine (1-20 microM), like dihydropyridines, inhibited spontaneous rhythmic and high K(+)-induced contractions, mainly through inhibition of the voltage-dependent (L-type) Ca++ current. The tonic component of high K+ contractions was inhibited more than the phasic component, correlating to voltage-dependent inhibition of Ca++ current by the drug. Azelastine (IC50 of 0.25 microM), a known histamine blocker, also reversibly inhibited alpha-1 agonist-induced contractions in the presence and absence of extracellular Ca++. Both major pathways of pharmacomechanical coupling, agonist-induced Ca++ release from the sarcoplasmic reticulum and Ca++ sensitization of the regulatory/contractile apparatus were blocked by the same concentration of drug in permeabilized as in intact muscle. Inositol 1,4,5-trisphosphate-induced Ca++ release and guanosine 5'-O-(tau-thiotriphosphate)-induced Ca++ sensitization, however, were not inhibited. Azelastine at high (greater than 10 microM) concentrations reversibly inhibited Ca(++)-activated contraction, more potently at lower Ca++ concentration and in phasic smooth muscle, but inhibited neither adenosine 5'-O-(tau-thiotriphosphate)-induced, Ca(++)-independent nor phorbol ester-induced contractions. These results indicate that azelastine is a genuine Ca++ antagonist that inhibits voltage-gated Ca++ inward current and agonist-induced Ca++ release and Ca++ sensitization.

Animals↗
PubMed1992

[A case of hemophagocytic syndrome with multiple myeloma].

A case with multiple myeloma complicated with hemophagocytic syndrome (HS) is presented. Because pancytopenia, liver dysfunction and increase of mature histiocytes in the bone marrow appeared rapidly a diagnosis of HS was made. The patient died of multiple organ failure, despite steroid therapy. Autopsy revealed marked invasion of hemophagocytic histiocytes not only into the bone marrow but also into many other organs such as the liver, lymph nodes and kidneys. HS is a histiocyte proliferative disorders, which is likely to be seen in immunocompromised hosts, but there is no previous report about HS and multiple myeloma.

Bone Marrow↗
PubMed1992

Acute secretory travellers' diarrhoea caused by Vibrio cholerae non-01 which does not produce cholera-like or heat-stable enterotoxins.

An Australian tourist suffering from severe acute watery diarrhoea and dehydration due to Vibrio cholerae non-01 was studied. The V. cholerae strain isolated from the patient belonged to serovar 05. The organism did not produce any of the conventional enterotoxins including cholera-toxin (CT) or heat-stable toxins (NAG-ST) that are known to be associated with intestinal secretion. This report suggests that toxin(s) other than CT-like or NAG-ST may be involved in the pathogenesis of diarrhoea by some V. cholerae non-01 strains.

Acute Disease↗
PubMed1992

[Interferon therapy of idiopathic thrombocytopenic purpura].

The authors evaluated the efficacy of a daily administration of recombinant human alpha 2a interferon (IFN), given at a dose of 300MU for 12 consecutive days, in patients with steroid-nonresponsive or -dependent idiopathic thrombocytopenic purpura (ITP). Nine patients received courses of IFN therapy. Mean platelet counts rose from 1.39 to 10.9 x 10(4)/microliters and PAIgG decreased from 151.7 to 59.7 ng/10(7) cells. The maximum rise in platelet counts occurred from 10 to 42 days (mean 19.1) after the initiation of IFN. Complete response (CR) was achieved in 3 of 13 courses (23.1%), and partial response (PR) in 8 (61.5%). One CR case continued for longer than 20 months without further treatment, but intermittent IFN therapy was necessary for the other. The increment of the platelet counts was transient in all of the partial responders. No severe side effect requiring interruption of the course of IFN was experienced. Both serum IgG and PAIgG significantly correlated with the increment of platelet counts, therefore the mechanism of IFN on ITP was presumed to be associated with the inhibition of autoantibody production. Daily administration of IFN appears to be an effective and safe treatment protocol for refractory ITP.

Adult↗
PubMed1992

[Cellular architecture of the sheep myocardium and heart conduction system as revealed with silver-impregnation method].

Morphological studies were carried out to delineate the cellular architecture of the myocardium and heart conduction system in adult sheep using the silver-impregnation method. Reticular fibers were heavily stained in a deep black color, while collagen fibers were less intensely silver-stained in a brownish color. Individual working myocardial cells were ensheathed by thin reticular fibers and showed a polygonal form, and were connected with adjacent cells mainly end-to-end and sometimes side-to-side. Thick collagen septa were distributed between masses of myocardial cells. The nodal cells in both the sinoatrial (SA) node and atrioventricular (AV) node were spindle shaped, smaller in size than myocardial cells, and surrounded by thin reticular fibers. The bundles of SA node cells were linearly oriented, while those of AV node cells formed a reticular pattern. The cells in the His bundle and Purkinje system were oval in shape, larger in size than myocardial cells and formed the strands composed of 4-8 cells. Each stand was surrounded by thick reticular fibers. These cells had both end-to-end and side-to-side contacts. Purkinje cells were followed by transitional cells which were in contact with myocardial cells. On the other hand, the reticular fibers and collagen fibers showed characteristic structures at the different portion of heart. The present study discusses the topographical relationship between cardiac muscle cells containing the conduction system and the connective tissue sheaths surrounding muscle cells.

Animals↗
PubMed1992

[Dual nuclides SPECT for ventilation and perfusion study].

Dual nuclides SPECT using 81mKr and 99mTc-MAA for ventilation and perfusion study was performed in 24 subjects. Crosstalk of 81mKr to 99mTc-energy window was about 7.5% when ventilation and perfusion study were performed by 370 MBq of 81mKr gas and 185 MBq of 99mTc-MAA. Areas of low V/Q was significantly larger in SPECT study than in planar study, in 11 cases with various pulmonary diseases. High V/Q mismatches were also more clearly delineated in SPECT than in planar study. Dual nuclides SPECT study has advantages of obtaining V/Q distribution without movement artifacts and of simultaneous acquisition of ventilation and perfusion image. Area of high V/Q became larger in SPECT with crosstalk than in SPECT without crosstalk, but in the low V/Q area no significant difference was noted between SPECT with crosstalk and without crosstalk.

Female↗
PubMed1992

[A case of congenital esophago-bronchial fistula communicated between esophageal diverticulum and left main bronchus in the adult--a review of 47 cases in the Japanese literature].

We experienced a successful repair of congenital esophago-bronchial fistula communicated between esophageal diverticulum and left main bronchus in adult case. The patient was a 60-year-old female. She had much wet cough on taking meals since 10 years ago. At the mass screening, a esophago-bronchial fistula was detected by upper GI series. Barium esophagography revealed a fistula between esophageal diverticulum and left main bronchus. The resection of diverticulum and fistula were undergone. In the operation, there exited no adhesion or inflammation around the fistula, therefore it was easy to isorate from the surrounding tissues. This case was categorized as Brainbridge type I esophago-bronchial fistula communicated to left main bronchus. Forty-six cases of congenital esophago-bronchial fistula with diverticulum were reported in Japan, but no cases which communicated with left main bronchus were reported. Then it is assumed that this is the first case in Japan.

Bronchial Fistula↗
PubMed1992

Captopril ameliorates the posturally induced fall in creatinine clearance in patients with chronic glomerulonephritis.

The clinical usefulness of an angiotensin-converting enzyme inhibitor on the posturally induced fall in creatinine clearance (ClCr) was studied in patients with biopsy-proved chronic glomerulonephritis (CGN). After a change from supine to upright position, ClCr fell significantly in all patients. This fall was significantly ameliorated by the pretreatment with captopril (fall in ClCr 28.8 +/- 14.3% for nontreated vs 16.5 +/- 11.5% for treated patients; n = 12; p less than 0.05). The ameliorating effect was more marked in patients with mesangial cell proliferation (MP) than those without it (fall in ClCr 7.2 +/- 6.3% for MP vs 17.1 +/- 12.3% for no MP; n = 6; p less than 0.05). The results suggest that captopril apparently had a renoprotective effect on the orthostatic acute fall in ClCr in patients with CGN, especially those with MP.

Adult↗
PubMed1992

[High-dose cepharanthin therapy of idiopathic thrombocytopenic purpura].

Clinical efficacy of oral high-dose cepharanthin (40-60 mg/day) was evaluated in nine patients with idiopathic thrombocytopenic purpura who were unable to discontinue the administration of adrenocorticosteroids or immunosuppressive drugs. Mean platelet counts significantly (p less than 0.05) rose from 4.5 +/- 0.9 x 10(4)/microliters to 8.9 +/- 4.2 x 10(4)/microliters without any side effects. Two to five months after the initiation of this therapy, 4 patients, including 3 who could discontinue adrenocorticosteroids, kept their platelet counts over 10 x 10(4)/microliters. It was suggested that the oral administration of cepharanthin could be a beneficial and safe strategy for ITP.

Administration, Oral↗