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Biomedical subjects

M Shigeta

Publications and source records attributed to M Shigeta.

At least 73 records · Page 4Linked to original sources
PubMed1994

The effects of patients' sera with sperm-immobilizing antibodies on sperm of the Japanese monkey.

In order to study the interspecies cross-reactivity of sperm-immobilizing antibodies found in sera of women who were infertile for unknown reasons, we used the sperm-immobilization test to examine the effects of patients' sera with or without sperm-immobilizing antibodies on the sperm of the Japanese monkey (Macaca fuscata). Fourteen of 17 antibody-positive sera and 7 of 14 antibody-negative sera showed sperm-immobilizing activity with regard to monkey sperm. The sperm-immobilizing antibody that was active against both human and monkey sperm could be absorbed only by sperm from each corresponding species. The periodate treatment of human or monkey sperm markedly diminished their antibody-absorbing capabilities. Human and mouse monoclonal antibodies having sperm-immobilizing activity with regard to human sperm showed no sperm-immobilizing activity with regard to monkey sperm. These results indicate that the sperm-immobilizing activity of the sera of infertile women against human and monkey sperm might be due to antibodies with different specificities, which recognize a unique carbohydrate antigen epitope expressed in the sperm of each species.

Animals↗
PubMed1994

Respiratory muscle pressure analysis in pressure-support ventilation.

The extent to which respiratory muscles are exerted during partially supported ventilation is difficult to differentiate, because these muscles and the ventilator work simultaneously to produce ventilation. We have developed a new method for determining the pressure developed by the respiratory muscles in partially supported ventilation. In seven patients on pressure-support ventilation (PSV), pressure, flow, and lung volume change were measured at the airway opening. Various PSV levels (0-15 cmH2O) were applied to each patient in random order. By utilizing a model of respiratory mechanics, we calculated the pressure developed by the respiratory muscles and the inspiratory work performed by the muscles from the measured parameters by use of the resistance and elastance of the respiratory system obtained during controlled ventilation. Increasing PSV from 0 to 15 cmH2O modulated the resultant breathing pattern, i.e., increasing tidal volume and decreasing respiratory rate. The respiratory muscle pressure, although less negative, had a shape that corresponded to the shape of airway occlusion pressure at each PSV level, and both pressures decreased concomitantly with increasing PSV. The respiratory muscle work progressively decreased with increasing PSV. This analysis enabled clear and continuous quantifications of the respiratory muscle force generation and inspiratory work during partially supported ventilation.

Adult↗
PubMed1994

Effect of inhaled amiloride on water-induced bronchoconstriction in asthmatic children.

To determine whether the inhaled diuretic, amiloride, can modify bronchoconstriction induced by ultrasonically nebulized distilled water (UNDW) in asthmatic children, a double-blind, randomized, placebo-controlled study was done. The UNDW inhalation challenge was performed in 12 asthmatic children (nine boys and three girls; mean age +/- SEM, 11.2 +/- 0.75 yr), who had at least a 20% fall in FEV1 after UNDW inhalation. On separate days, these subjects underwent UNDW inhalation challenge after inhalation of amiloride (0.3 mg/m2 body surface area) or placebo (0.9% saline). Neither bronchodilation nor bronchoconstriction after amiloride inhalation was observed. The mean value and SEM of the UNDW PD20 after placebo inhalation was 4.55 +/- 0.80 ml. After inhalation of amiloride, PD20 increased to 7.93 +/- 0.75 ml (p < 0.01). We concluded that inhaled amiloride exerted a protective effect against UNDW-induced bronchoconstriction in asthmatic children.

Administration, Inhalation↗
PubMed1994

Age-related changes in bronchial hyperreactivity during the adolescent period.

To evaluate the influence of bronchial hyperreactivity on the improvement of asthma seen during adolescence, age-related changes of bronchial reactivity to methacholine (BRm) in adolescence were evaluated in two studies. Study 1 included 261 asthmatic children and 89 controls, aged 6-26 years, and in Study 2, yearly BRm variations from age 11 to 16 years of 23 asthmatic children of study 1 were studied. Methacholine inhalation challenge was performed by using an oscillation method; that is, respiratory resistance (Rrs) was directly measured by an oscillation technique, and subsequent doses were then doubled, until a twofold increase in Rrs from the baseline was reached. The cumulative dose of methacholine at the inflection point of the Rrs was considered to represent the BRm. From ages 6 to 9, Dmin in the asthmatic children were low (from 2.07 units to 1.38 units), but after age 12, the value gradually increased, and finally became sustained after age 16 (from 2.27 units to 4.80 units). These same age-related changes were seen in the age-matched controls. From ages 6 to 11, Dmin in the control children were also low (from 8.07 units to 12.9 units), but after age 12, Dmin gradually increased, and finally became sustained after age 16 (from 18.5 units to 43.2 units). However, for each year, the Dmin of the asthmatic children were significantly lower than those of the controls. Further, the mean of yearly Dmin variation from age 13 was less than that of younger subjects (from 0.65 unit/year to 0.92 unit/year, from 1.16 units/year younger subjects (from 0.65 unit/year to 0.92 unit/year, from 1.16 units/year to 4.16 units/year, respectively). We, therefore, concluded that the natural age-related BRm changes and the increased stability of yearly BRm variation that occur in adolescence may play a role in the improvement of childhood asthma seen during this period.

Adolescent↗
PubMed1993

Horizontal component of electro-oculogram as a parameter of arousal in dementia: relationship between intellectual improvement and increasing arousal under pharmacotherapy.

Although nootropics and metabolically active compounds sometimes attenuate intellectual deficits of dementia patients, this mechanism has not been discussed or investigated. The authors hypothesized that these compounds act to enhance attention and/or concentration by increasing the arousal level, and then improve intellectual functions. Based on this hypothesis, the authors investigated the arousal level and the improvement of intellectual functions in ten patients with Alzheimer type dementia and ten patients with multi-infarct dementia before and after 3 months pharmacotherapy using bifemelane hydrochloride. They then analyzed whether the increases in arousal level involves or relates to the improvement of intellectual functions. On the 20 patients, psychological tests were carried out, and the arousal level was evaluated using the frequency of rapid eye movements in the electro-oculogram (EOG) before and after 3 months administration of bifemelane hydrochloride. As a result, a significant positive correlation was observed between the improvement on the Hasegawa's dementia scale and the rate of increase in rapid eye movements in the EOG. The EOG monitoring can be a great help in establishing an objective evaluation method on drug efficacy.

Aged↗
PubMed1993

Responders and non-responders to bifemelane hydrochloride in Alzheimer-type and multi-infarct dementia.

Although metabolically active compounds sometime attenuate cognitive deficits of dementia patients, this mechanism has not been discussed or investigated. We hypothesized that these compounds improve cognitive disorders not by directly acting on this cognitive function, but by increasing the arousal level. Based on this hypothesis, we investigated the change of arousal levels and the improvement of intellectual functions in 10 patients with Alzheimer-type dementia (ATD) and 10 patients with multi-infarct dementia (MID) before and 3 months after pharmacotherapy using bifemelane hydrochloride. For each patient, a psychological test battery was carried out and the arousal level was evaluated using the frequency of rapid eye movements in the electro-oculogram (EOG) and the frequency analysis of electroencephalogram (EEG) before and after the treatment. Evaluation of the cognitive improvement was made and eight out of the 20 patients were regarded as responders to the treatment. The frequency of small rapid eye movements (SREM) in the EOG increased significantly only in responders and the rate of change in SREM appearance in responders was significantly different from that in non-responders. This finding suggests that a part of the intellectual improvement in ATD and MID results from the increased level of arousal.

Aged↗
PubMed1993

EEG regional changes during long-term treatment with tetrahydroaminoacridine (THA) in Alzheimer's disease.

Three patients with Alzheimer's disease of mild type received long-term treatment with THA at doses between 40 mg to 160 mg daily. This study describes the effects of THA on EEG, seen during long-term and high dose treatments. After short-term treatment, the changes of the mean frequency in the temporal and parieto-occipital regions varied between patients, but in the frontal region a significant increase of the mean frequency was seen in all patients. The EEG improvement seen in the frontal region was more significant than that for the other regions at low dose of THA (80 mg). During long-term treatment, we observed different types of EEG changes. The early improvement seen in two patients was temporary and reverted to the pre-treatment value. In a third patient who did not show marked improvement after short-term treatment, an improvement was seen in all regions after longer treatment. Treatment with high doses of THA (120 mg or 160 mg) induced a marked increase in the mean frequency not only in the frontal region but also in the temporal and parieto-occipital regions. Higher doses of THA seem to affect larger areas of the brain than lower doses of THA.

Alzheimer Disease↗
PubMed1993

[A clinical study on upper urinary tract calculi treated with extracorporeal shock wave lithotripsy (ESWL) monotherapy, with regard to bacteriuria before ESWL treatment].

To study a clinical problem in urolithiasis complicated with bacteriuria treated by extracorporeal shock wave lithotripsy (ESWL), we studied relationships between the frequency of bacteriuria and some clinical factors such as sex, location of, size of and composition of calculi in patients with upper urinary tract calculi. We also evaluated whether bacteriuria caused fever elevation after ESWL monotherapy. Six hundred seventy patients with upper urinary tract calculi, 440 renal calculi and 230 ureteral calculi, were subjected to the present study. The results were summarized as follows: 1) Bacteriuria was found in 40 of 440 patients with renal calculi (9%) and 12 of 230 patients with ureteral calculi (5%). 2) The frequency of bacteriuria was significantly higher in female (11%) than in male (6%) (p < 0.05). 3) Ten strains of Pseudomonas aeruginosa, 7 of Escherichia coli and 6 of Proteus mirabilis were isolated in patients with bacteriuria. 4) On the location of renal calculi in patients with bacteriuria, 37 out of 40 patients (93%) were found in R2. In contrast, bacteriuria was the most frequently found in DS 6 (19%), whereas the positive rates were about 10% in DS 3 (7%), DS 4 (*7%) and DS 5 (9%). The presence of bacteriuria was not related to the location of calculi or the size of calculi in patients with ureteral calculi. 5) Most of the calculi with bacteriuria were composed of magnesium ammonium phosphate or the mixture of calcium phosphate and carbonate with or without oxalate. 6) Patients with bacteriuria had a significantly higher rate of fever elevation after ESWL than those without bacteriuria (p < 0.01).

Adult↗
PubMed1993

[The correlation between changes in EEG and eye movement (EOG) accompanied by lowered arousal level].

We investigated the correlation between the components of spontaneous eye movement (EOG) and EEG in six healthy individuals. The study was conducted in three periods; from the resting to drowsy stage, from the drowsy to spontaneous awakening stage, and in the forced waking stage. EEG, as registered from bipolar electrodes attached between the left parietal region (P3) and the left occipital region (O1), was monitored continuously by the FFT method with a segment of 12.8 seconds. Rapid eye movement and slow eye movement were observed simultaneously. In conclusion, even when the arousal level varies considerably, there is a close correlation between frequency of rapid eye movement and EEG patterns of 10.16 integral of 10.94 Hz & 17.97 integral of 19.53 Hz (simple correlation p < 0.01). Additionally, during the forced waking period (after stage 2), delta and theta bands increased in cases along with sleepiness. Even if the depth of sleep was the same, one's mood upon awakening was determined by the frequency of slow waves before awakening.

Adult↗
PubMed1992

Plasma theophylline concentrations and airway function in asthmatic children receiving standard and modified RTC therapy.

The effects of three different dosage schedules for sustained-release theophylline (Theolong) were investigated in children with asthma. With regimen II (unequal doses at 0800 h and 2000 h), the maximum plasma theophylline concentration following the evening dose was significantly higher than that following the morning dose, and also was larger than that following the evening dose with regimen I (equal doses at 0800 and 2000 h). With regimen III (equal doses at 0600 h and 2100 h), the mean theophylline concentration-time curve showed a single large peak at 1100 h, whereas with regimen I, there were two peaks at 2300 and at 1400 h. Knowledge that a change of the dosage schedule can affect the pharmacokinetics of theophylline in this way should aid physicians in its safe and effective use.

Asthma↗
PubMed1992

[Assessment of alveolar epithelial permeability in progressive systemic sclerosis (PSS) using 99mTc-DTPA (diethylene triamine penta acetate) aerosol inhalation].

To evaluate alveolar epithelial damage in PSS, we studied pulmonary epithelial permeability by measuring the clearance of inhaled 99mTc-DTPA aerosol and performing thin slice CT scan, pulmonary function tests and right heart catheterization in 28 patients with PSS. The 99mTc-DTPA clearance rate (kep value) in PSS was greater than in 11 non-smoking normal subjects (18.2 +/- 7.63 x 10(-3)/min vs. 9.12 +/- 0.77 x 10(-3)/min, p less than 0.01). In PSS, the kep value did not correlate with age, sex, duration of illness, dermal lesions, % vital capacity, or PaO2. In contrast, the kep value showed significant correlations with %DLco (diffusing capacity for carbon monoxide), extent of interstitial lesions evaluated by CT scan (CT score), and mean pulmonary artery pressure. On the other hand, the kep value was high in some patients with normal CT scan and normal %DLco. These findings indicate that pulmonary interstitial lesions in PSS are accompanied by alveolar epithelial damage, and that the clearance of 99mTc-DTPA may be an early predictor of interstitial change.

Administration, Inhalation↗
PubMed1991

Recognition of carbohydrate antigen epitopes by sperm-immobilizing antibodies in sera of infertile women.

STUDY OBJECTIVE: To study carbohydrate natures in the antigen epitopes corresponding to sperm-immobilizing antibodies in infertile women. DESIGN: Antibody absorption with human sperm and seminal plasma before and after treatments with trifluoromethanesulfonic acid or sodium metaperiodate. PATIENTS: Thirty-three patients who showed a positive sperm immobilization test provided their sera for the experiment. RESULTS: In 25 patients' sera whose sperm-immobilizing antibodies were absorbed with human seminal plasma, the antibody absorbing capabilities were completely abolished by deglycosylation treatment with trifluoromethanesulfonic acid. The sperm-immobilizing antibodies in 4 patients' sera were absorbed out with sperm membrane fraction before the treatment but not after the treatment with trifluoromethanesulfonic acid. In some patients' sera, the antibody-absorbing capabilities of ejaculated sperm were markedly reduced by sodium metaperiodate treatment. CONCLUSION: The majority of sperm-immobilizing antibodies in infertile patients might be generated to carbohydrate structures of the sperm-coating antigens or sperm membrane antigens.

Antibodies↗
PubMed1991

Ability of polymorphonuclear leukocytes to generate active oxygen species in children with bronchial asthma. Use of chemiluminescence probes with a Cypridina luciferin analog and luminol.

Airway inflammation with polymorphonuclear leukocytes (PMN) may play an important role in bronchial hyperresponsiveness (BHR). PMN generate superoxide anion (O2-) and other oxygen radicals that can damage lung tissue. We investigated the ability of peripheral PMN of children with bronchial asthma and control subjects to generate O2- and other active oxygen species using a 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one, a highly sensitive and specific chemiluminescence (CL) probe for O2-, and luminol-dependent CL. The ability of PMN of subjects with asthma to generate O2- and other active oxygen species was significantly greater than that of PMN of control subjects when stimulated with opsonized zymosan (OZ), phorbol myristate acetate or N-formyl-methionyl-leucyl-phenylalanine. Furthermore, in the same asthmatic children, the generation of O2- and other active oxygen species was significantly higher with attacks than without attacks when PMN were stimulated with OZ. We also demonstrated that O2- generation correlated with the degree of BHR to inhaled histamine. These results suggest that PMN of asthmatic children, especially those with attacks, generate more active oxygen species than that of control subjects and that airway inflammation caused by O2- may be closely related to BHR in subjects with bronchial asthma.

Adolescent↗
PubMed1991

Studies of dialysates from Dermatophagoides farinae: partial purification and haptenic properties of dialysates from Dermatophagoides farinae.

Dialysates from Dermatophagoides farinae were partially purified. Fractionation on HPLC and anion exchange chromatography revealed that the dialysates consisted of 5 major fractions of glycoprotein whose apparent molecular sizes were 5.1, 4.1, 3.2, and less than 1.35 kD on HPLC. The apparent molecular size of two fractions was 5.3 and 2.9 kD on SDS-PAGE. They were basic glycoproteins which had a pI ranging from 7.46 to 8.71 on PAG-IEF. These fractions were allergenic in the RAST and ELISA inhibition tests but not in the skin prick test (SPT). Our results suggest that the dialysates from D. farinae have haptenic properties. The dialysates from D. farinae (low molecular weight) and its 5 fractions bound noncovalently to human serum albumin (HSA) at the free tyrosine residues of HSA. They proved to bind noncovalently to serum proteins and collagens. Once they bound to proteins, the conjugates became allergenic not only in the RAST and ELISA inhibition test but also in the SPT. Our results provide evidence that the dialysates from D. farinae have haptenic properties.

Agammaglobulinemia↗
PubMed1991

[11 cases of anaphylaxis caused by grand keyhole limpet (abalone like shellfish)].

We reported 11 cases of patients who developed moderate to severe anaphylactic reactions induced by the ingestion of grand keyhole limpet (GKL) and abalone. Specific IgE-mediated hypersensitivity to these shellfish was demonstrated by history, skin prick test, RAST and immunoblotting. The RAST inhibition technique revealed cross antigenicity between GKL, abalone and keyhole limpet hemocyanin. By immunoblotting analysis, the major antigens of GKL are shown in the MW range of about 38 Kd and 80 Kd.

Adolescent↗
PubMed1991

[Immunoglobulin levels, number of eosinophils in the peripheral blood and bronchial hypersensitivity in children with Mycoplasma pneumoniae pneumonia].

We studied the immunoglobulin levels and the number of eosinophils in the peripheral blood during the course of Mycoplasma pneumoniae pneumonia in children. Nineteen children with Mycoplasma pneumoniae pneumonia, including eight asthmatic children, were the study subjects. In eight of them, bronchial hypersensitivity was also measured by the Astograph method in both the convalescent phase and the healing (non-symptomatic) phase. The results were as follows. 1) Total serum IgA and IgM increased in the convalescent phase. 2) The levels of total serum IgE were higher in the acute phase and then decreased gradually. 3) The number of eosinophils in the peripheral blood increased over the acute-to-convalescent phase. 4) Bronchial hypersensitivity increased after Mycoplasma pneumoniae pneumonia, and two asthmatic children who exhibited bronchial hypersensitivity had asthmatic attacks. 5) Bronchial hypersensitivity persisted for over one month in two non-asthmatic children.

Adolescent↗