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Biomedical subjects

M Yanai

Publications and source records attributed to M Yanai.

At least 19 recordsLinked to original sources
PubMed1998

A newly developed on-line monitoring system for the determination of serum electrolytes and urea during hemodialysis.

Continuous monitoring of serum solute concentrations throughout a dialysis session could be beneficial for the prevention of intradialytic morbidity such as hypotension and for the confirmation of dialysis adequacy. In this paper, we introduce a new on-line monitoring system for use during hemodialysis sessions, a system developed for the continuous observation of serum biochemical data. Using this system, we also show the possibility of clinical applications. Intradialytic hypotension could be prevented by the observation of filtrate sodium concentration and the control of dialysate sodium concentration. The termination of a dialysis session could be decided by the observation of the filtrate urea nitrogen, on the basis of the Kt/V urea ratio. Because monitoring for other solutes such as calcium and creatinine is theoretically available, clinical applications will continue to increase in the future.

Adult↗
PubMed1998

Protective effect of administration of skim milk on exogenous and endogenous infection in mice.

In order to minimize the denaturation of proteins in milk, normal cow's milk was pasteurized at 61 C for 20 min. The protective effects of the thus prepared skim milk (low-heat skim milk) on exogenous and endogenous infection were examined as compared with conventional skim milk which was pasteurized at 121 C for 2 sec. The antibody titers to Listeria monocytogenes and Escherichia coli of low-heat skim milk were almost equal to that of raw milk, while no antibody was detected in the conventional skim milk. When mice were given low-heat skim milk or conventional skim milk, the incidence of the translocation of orally inoculated Listeria monocytogenes to the spleen was lower in the low-heat skim milk group than that in the conventional skim milk group. The life span of 7 Gy X-ray irradiated mice given low-heat skim milk was significantly prolonged in comparison to that of mice given conventional skim milk. However, there were no differences in the number of bacteria in the feces or IgA production by Peyer's patch cells between the two groups. These results suggest that antibodies in low-heat skim milk, which still have reactivity to exogenous or indigenous bacteria, may contribute to the protective effects against bacterial infection.

Animals↗
PubMed1998

Deposition and clearance of inhaled 18FDG powder in patients with chronic obstructive pulmonary disease.

As freon is limited in its use as a generator for aerosol inhalation, powder particles are used as an alternative for inhalation therapy. The pulmonary deposition and clearance of inhaled powder particles was studied by positron emission tomography (PET) in ten patients with chronic obstructive pulmonary disease (COPD) and in five normal controls. The powder, 5 microm in mean diameter, was water soluble and labelled with 2-deoxy-2-[18F]-fluoro-D-glucose (18FDG). Powder inhalation was done with single deep inspiration from residual volume to total lung capacity. The initial deposition ratio in the right or left lung field to total inhaled dose, measured by an anteroposterior rectilinear scan, did not differ between normals and COPD patients. Ratios of radioactivity detected within the central and peripheral regions (the central to peripheral ratio) measured by the PET scan was not significantly different between COPD patients (4.8+/-2.6, mean+/-SD) and normals (2.6+/-0.8, mean+/-SD). However, the regional powder deposition in peripheral lung fields measured by the PET scan was significantly more uneven in COPD patients than in normal patients. The clearance rate of 18FDG, defined as the retention ratio of 18FDG activity to the initially deposited 18FDG at 60 and 120 min after inhalation, in the trachea, large bronchi or peripheral lung fields measured by tomographic scan showed a wider variation in COPD patients than in normals. To conclude, inhaled powder tended to be deposited more centrally and was distributed more unevenly in the peripheral lung in chronic obstructive pulmonary disease patients than in normals. This could be a limitation of powder inhalation used for therapy in chronic obstructive pulmonary disease patients.

Administration, Inhalation↗
PubMed1998

N2733, 1-[3-(3-pyridyl)-acryloyl]-2-pyrrolidinone hydrochloride inhibits LPS-induced TNF-alpha production and improves survival in endotoxemic mice.

N2733, 1-[3-(3-pyridyl)-acryloyl]-2-pyrrolidinone hydrochloride, was examined for its effect on TNF-alpha production by human myeloid THP-1 cells stimulated with lipopolysaccharide (LPS). N2733 inhibited LPS-induced release of TNF-alpha from THP-1 cells with an IC50 of 11 microM. N2733 did not affect the cell viability at the concentration of 50 microM or 100 microM. This indicates that N2733 is a potent inhibitor for TNF-alpha production without severe cytotoxicity. N2733 was also studied in two murine endotoxin shock models induced with LPS. One model was DBA/2 mice injected with LPS (5.6 mg/kg, i.v.), which increased the serum level of TNF-alpha within 1 hr. Treatment of these mice with N2733 (100 mg/kg x 2, i.p.) decreased the serum level of TNF-alpha significantly. Another model was DBA/2 mice induced with LPS (30 mg/kg, i.v.), which reduced the survival rate to 30% during 7 days. Administrations of 30 mg/kg and 100 mg/kg N2733 (i.v.) restored the survival rates to 60% and 90% respectively. Our data demonstrate that N2733 inhibits LPS-induced TNF-alpha production, and this response is associated with an improvement in the survival rate of endotoxemic mice.

Animals↗
PubMed1997

Treatment outcome and prognostic factors in childhood acute myeloblastic leukemia: a report from the Japanese Children's Cancer and Leukemia Study Group (CCLSG)

Treatment outcome and prognostic factors were evaluated in 152 children with acute myeloblastic leukemia (AML) treated on three consecutive protocols (ANLL 861, 8912, 9205) of the Children's Cancer Leukemia Study Group (CCLSG, Japan). In the ANLL 9205 protocol, anthracycline was used with a continuous infusion of cytosine arabinoside, followed by an intensive sequential post remission chemotherapy of short duration. Forty-two of these 46 patients (91.3%) achieved complete remission, and 58.8% of these patients projected a 3-year disease-free survival. These results were apparently superior to those obtained with the ANLL 861 and 8912 protocols, which used conventional doses of multiple drugs followed by a moderate post remission chemotherapy of long duration. This favorable response with the ANLL 9205 protocol was attributed mainly to the high induction rate of patients with the M4 and M5 FAB subtypes, as compared to those in the previous two protocols (93.3% in ANLL 9205 vs. 57.9% in ANLL 861 + 8912; P < 0.05). The ANLL 861 and 8912 protocols, an older age (> or = 8 years), higher WBC counts (> or = 10 x 10(9)/1) and all predicted an increased risk of relapse and decreased the survival following univariate analysis (P < 0.05). An older age and high WBC count continued to predict an increased risk of relapse in multivariate analyses: patients with an age > 8 years and WBC counts > 10 x 10(9)/1 had a 4.5 times higher risk of relapse than patients without these adverse features.

Adolescent↗
PubMed1997

Body mass index variations by age and sex, and prevalence of overweight in Japanese adults.

OBJECTIVE: To determine the reference value of BMI for Japanese subjects and to estimate the prevalence of overweight based on this reference value. DESIGN: Epidemiological analysis with the LMS method, which provides a way of obtaining normalized BMI distributions. SUBJECTS: 7508 Japanese subjects aged 18-69 y in 1993. MEASUREMENTS: Height, age and body weight. CALCULATION: BMI was calculated and tables for percentiles of BMI were plotted against age and sex. Furthermore, the prevalence of overweight was estimated based on 85th percentile of BMI in the men and women 20-29 y of age, who were considered the reference group. RESULTS: The geometric mean BMI and the prevalence of overweight in men was highest in the 30-39 y age group. For women the maximum BMI and prevalence of overweight occurred in the decade 50-59 y. The cut-off points for overweight in this sample were 24.7 kg/m2 for men and 22.6 kg/m2 for women. These are considerably lower than the figures of 27.8 kg/m2 and 27.3 kg/m2 estimated for Americans. CONCLUSIONS: The prevalence of obesity in Japanese populations should be estimated using ethnic specific values of BMI, rather than those drawn from Caucasians who tend to have higher BMI in each age group. The prevalence of overweight is increased as age increased in both sexes, especially in women.

Adolescent↗
PubMed1997

New strategies for aspiration pneumonia.

Aspiration pneumonia is associated with decreases in both swallowing and cough reflexes and is the most common cause of death in the elderly. Basal ganglia strokes might predispose these patients to develop pneumonia owing to reductions of both reflexes, resulting in frequent aspiration during sleep. An impairment of dopamine metabolism in the basal ganglia is observed in these patients and levodopa administration improves the impaired swallowing reflex. Both swallowing and cough reflexes are mediated by endogenous substance P (SP) released from vagal sensory nerves in the pharynx and upper airways. The addition of a low dose of capsaicin to liquid or food, which stimulates the release of SP, may help prevent aspiration pneumonia. Angiotensin-converting enzyme inhibitor decreases SP catabolism resulting in improvements in both reflexes. Oral care and the sitting position after meals may decrease aspiration pneumonia in the elderly.

Aged↗
PubMed1997

[Treatment results in childhood acute myeloblastic leukemia--a report of clinical trials of a past decade from the Japanese children's Cancer and Leukemia Study Group (CCLSG)].

Treatment results were evaluated in 167 children with acute myeloblastic leukemia (AML) treated on four protocols (ANLL 861, 8912, 9205, APL-ATRA) of the Children's Cancer Leukemia Study Group. In the ANLL 9205 protocol, anthracycline was used with a continuous infusion of cytosine arabinoside, followed by an intensive sequential post remission chemotherapy of short duration, 42/46 patients (91.3%) achieved complete remission, and 58.8% of these patients projected a 3-year disease free survival. These results were apparently superior to those obtained with the ANLL 861 & 8912 protocols, which used conventional doses of multi drugs followed by a moderate post remission chemotherapy of long duration. This favorable response with the ANLL 9205 protocol was attributed mainly to the high induction rate of patients with the M4 and M5 FAB subtypes, as compared to those in the previous two protocols (91.3% in ANLL 9205 vs 57.9% in ANLL 861 + 8912; p < 0.05). No significant difference in the patients outcome was found between the chemotherapy group and allogenic bone marrow transplantation group in the ANLL 9205 study. The patients with the M3 FAB subtype treated with the APL-ATRA protocol which consisted of an alternative use of all-trans retinoic acid and chemotherapy significantly prolonged event free survival as compared with the patients treated with ANLL 861/8912 protocols without all-trans retinoic acid.

Anthracyclines↗
PubMed1996

Intracellular pressure is a motive force for cell motion in Amoeba proteus.

The cortical filament layer of free-living amoebae contains concentrated actomyosin, suggesting that it can contract and produce an internal hydrostatic pressure. We report here on direct and dynamic intracellular pressure (P(ic)) measurements in Amoeba proteus made using the servo-null technique. In resting apolar A. proteus, P(ic) increased while the cells remained immobile and at apparently constant volume. P(ic) then decreased approximately coincident with pseudopod formation. There was a positive correlation between P(ic) at the onset of movement and the rate of pseudopod formation. These results are the first direct evidence that hydrostatic pressure may be a motive force for cell motion. We postulate that contractile elements in the amoeba's cortical layer contract and increase P(ic) and that this P(ic) is utilized to overcome the viscous flow resistance of the intracellular contents during pseudopod formation.

Amoeba↗
PubMed1996

Prostaglandin production via induction of cyclooxygenase-2 by human gingival fibroblasts stimulated with lipopolysaccharides.

The purpose of the present study was to investigate the involvement of cyclooxygenase-1(COX-1) and cyclooxygenase-2 (COX-2) in PGE2 production by human gingival fibroblasts stimulated with lipopolysaccharides (LPS) from periodondopathogenic bacteria. LPS were isolated from Porphyromonas gingivalis (P. gingivalis), Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) and Eschericia coli (E coli) by the phenol-water procedure. The three LPS preparations produced PCE2 up to 48 h in a time-dependent manner in human gingival fibroblasts. P. gingivalis-LPS was the most potent stimulator of PGE2 production and, to a lesser extent, A actinomycetemcomitans- and E coli-LPS. Treatment of the cells with indomethacin, a non selective COX-1/COX-2 inhibitor and NS-398, a selective COX-2 inhibitor, completely depressed PGE2 production. Treatment of dexamethasone, known to inhibit COX-2 expression, also significantly prevented PGE2 production. Immunohistochemical staining of COX-2 protein demonstrated that expression of COX-2 protein was increased at 24 h after P gingivalis-LPS stimulation, while expression of COX-1 protein was not affected by P. gingivalis-LPS. In order to investigate the regulation of PGE2 production. P. gingivalis-LPS-stimulated cells were treated with herbimycin A and genistein, both inhibitors of tyrosine kinases. Both the inhibitors significantly inhibited PGE2 production. Herbimycin A treatment depressed expression of COX-2 protein. These data suggest that human gingival fibroblasts stimulated with LPS from periodontopathogenic bacteria mainly produce PGE2 not by COX-1, but by COX-2, induction of which may be regulated by tyrosine kinase and that the produced PGE2 may be involved in the pathogenesis of periodontal diseases.

Aggregatibacter actinomycetemcomitans↗
PubMed1996

Blood density monitoring during dialysis.

Continuous monitoring of blood density (BD) was preformed in 4 stable dialysis patients in 20 sessions using a density meter based on a mechanical oscillator technique. Mean predialysis and postdialysis BDs were 1.0427 +/- 0.0031 g/cm3 and 1.0502 +/- 0.0055 g/cm3, respectively. For similar predialysis to postdialysis total body water reduction, significant difference in the mean BD increase was found between hypotensive and nonhypotensive groups (1.29 +/- 0.07%, 0.47 +/- 0.12%, respectively; p < 0.001). Eight hypotensive episodes occurred during 6 sessions. The mean value of the blood density changes slope (dBD/dr) during the 5 min preceding a hypotensive episode increased about 2.5 times more than did the mean of the predialysis to postdialysis blood density slope (27.6 +/- 2.2 g/cm3.min.10(-5), 10.5 +/- 0.4 g/cm3.min.10(-5), respectively; p < 0.001) under the condition of a constant ultrafiltration rate of 18.9 +/- 0.6 ml/min. Continuous monitoring of blood density allows abrupt change in plasma volume to be identified and seems to have a potential utility to the prevention of symptomatic hypotension episodes in patients receiving hemodialysis.

Adult↗
PubMed1995

Dependence of collateral and small airway resistances of CO2 and volume in dog lobes.

We examined the hypothesis that collateral channels were identical within small airways and ducts, therefore both should respond similarly to chemical and mechanical stresses. A double lumen catheter was wedged into a segmental bronchus of the dog and humidified air or 10% CO2 in air (Vs) flowed at a segmental bronchial pressure (Pb) of 2 cm H2O. A small circular area about 1 cm diameter was peeled from the wedged segment and covered with a capsule glued to the surrounding pleura for measuring either a small airway flow (Vsaw) or capsule pressure (Pcap). Collateral resistance (Rcoll) and small airway resistance (Rsaw) were calculated as Rcoll = Pb/(Vs-Vsaw), Rsaw = (Pb-Pcap)/Vsaw, respectively. Hypocapnia (air) resulted in increases in Rcoll and Rsaw, while hypercapnia (10% CO2) generally had the opposite effect. Gcoll and Gsaw both increased linearly with lung volume (VL). The pattern of the responses of Rsaw closely paralleled those of Rcoll to local hypercapnia and hypocapnia, and to changing VL, implying that the major sites of resistance along collateral channels and along the airways are functionally and structurally similar.

Airway Obstruction↗