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Biomedical subjects

H Kamimura

Publications and source records attributed to H Kamimura.

At least 37 records · Page 2Linked to original sources
PubMed1996

Continuous measurement of blood pressure, heart rate and left ventricular performance during and after isometric exercise in head-out water immersion.

Experiments were performed to determine the changes in blood pressure (BP), heart rate (HR) and left ventricular function during and after isometric knee extension during thermoneutral (35 degrees C) head-out water immersion (HWI) or in air. Seven healthy male subjects mean age 24 (SD 3) years kept their knees extended (60% maximal voluntary extension) until they reached exhaustion. The mean BP at rest was 80 (SD 10) and 78 (SD 8) mmHg [10.7 (SD 1.33) and 10.4 (SD 1.07)kPa] in air and during HWI, respectively, (NS). They increased progressively (P < 0.01) during contraction and reached maximal values of 148 (SD 22) and 143 (SD 26) mmHg [19.7 (SD 2.93) and 19.1 (SD 3.47)kPa] in air and in HWI, respectively, (NS). The mean HR at rest was 74 (SD 8) and 70 (SD 11) beats.min-1 in air and in HWI, respectively, (NS). They also increased progressively, (P < 0.01) and reached 126 (SD 14) and 118 (SD 17) beats.min-1 in air and in HWI, respectively, (NS). The changes in BP and HR during contraction in HWI tended to be smaller than those in air (NS). Left ventricular end diastolic diameters (dd) at rest in HWI were greater than those in air and were maintained at higher values during and after isometric contraction. In contrast, dd decreased during isometric contraction in air (P < 0.01). The change of left ventricular systolic diameters (ds) in HWI was no different to those in air. From these findings, isometric exercise in thermoneutral HWI would seem to be characterized by a greater dd than in air and this could be useful for patients with deconditioning effects such as orthostatic hypotension.

Adult↗
PubMed1996

Pharmacokinetics of tamsulosin hydrochloride in patients with renal impairment: effects of alpha 1-acid glycoprotein.

The pharmacokinetics of tamsulosin hydrochloride in patients with renal impairment were compared with those in healthy volunteers, and the factors that influenced plasma levels of tamsulosin were elucidated. A single oral dose of 0.2 mg of tamsulosin was given and blood and urine samples were obtained for 36 hours after administration. Unbound plasma concentration of tamsulosin was measured by a combination of equilibrium dialysis and liquid chromatography tandem mass spectrometry methods to examine the effect of protein binding on the pharmacokinetics of tamsulosin. Mean values for maximum concentration (Cmax) and area under the concentration-time curve (AUC) of total drug (Cmax,t and AUC1) in patients with renal impairment were 73% and 211% greater, respectively, than those in healthy volunteers. Mean Cmax and AUC of unbound drug (Cmax,u and AUCu), however, were almost the same in the two groups. A high correlation was found between alpha 1-acid glycoprotein (alpha 1-AGP) concentration and AUCt, but no correlation was found between alpha 1-AGP concentration and AUCu,0-36) or between creatinine clearance (ClCR) and AUCu,0-36). These results show that in patients with renal impairment, the pharmacokinetics of tamsulosin are affected by the change in protein binding that is associated with alteration of plasma alpha 1-AGP concentration, but are not largely affected by the decrease in the renal excretion. Although total tamsulosin levels increased as plasma protein binding increased, unbound tamsulosin levels (which are directly associated with the pharmacologic effects) remained unchanged in these patients.

Adrenergic alpha-Antagonists↗
PubMed1992

Enhanced elimination of theophylline, phenobarbital and strychnine from the bodies of rats and mice by squalane treatment.

Our previous study suggested that squalane would be a good candidate for an antidote to reduce the toxicity of drug ingested accidentally at a high dose by enhancing the drug elimination from the body. In the present study, we investigated whether squalane given orally could enhance the elimination of theophylline, phenobarbital and strychnine which were administered parenterally to rats or mice. Squalane increased the fecal excretion of theophylline and reduced the serum level of the drug in rats. Squalane accelerated the fecal excretion of strychnine in mice. These results suggest that squalane may stimulate more the elimination of neutral (theophylline) or basic (strychnine) drugs which should be present in unionized form in intestinal lumen, than that of acidic drugs.

Algorithms↗
PubMed1991

[Studies on distribution and excretion of squalane in dogs administered for 2 weeks].

In the previous papers, we demonstrated, by using rats, that squalane (2,6,10,15,19, 23-hexamethyltetracosane) could stimulate the fecal excretion of 2,3,4,7,8-pentachlorodibenzofuran, the most important etiologic agent of Yusho, which was accumulated in the body of rat. We also reported that, in rats and dogs, squalane did not show any appreciable toxic signs during 3-month treatment, though a part of squalane was absorbed from gastrointestinal tract of dogs. In the present paper, we have investigated the elimination of absorbed squalane in beagle dogs. During the treatment with squalane orally at a dose of 1200 mg/kg/day for 14 days, the fecal excretion of squalane per day was 65-90% of the daily dose. After the treatment (on the day 14), squalane levels in blood and hair were about 30 ppm and 14640 ppm, respectively. On the day 56 after the first dosing, squalane was not detected in blood. On the day 70, squalane level in hair was reduced to about 1% of that on the day 14. Squalane levels in skin, liver, adipose tissue and small intestine on the day 70 were also reduced compared with that on the day 42. Moreover, small amount of squalane was still excreted into feces from the day 15 to the day 70. These results suggested that absorbed squalane was gradually excreted through feces and skin in dogs.

Administration, Oral↗
PubMed1991

[The evaluation of the effect of Estracyt on prostatic cancer].

The clinical effect of Estracyt on untreated prostatic carcinoma was evaluated. The subjects consisted of 51 of 71 patients with prostatic carcinoma who were observed for 6 months or more after oral administration of 560 mg of estramustine phosphate. This drug was effective in all patients: markedly effective in 34 (66.6%), moderately effective in 13 (25.5%), and slightly effective in 4 (7.8%). During the observation period varying from 6 months to 2 years and 6 months, 7 patients had recurrence of progression. The interval between the drug administration and recurrence of progression varied from 6 months to 1 year and 10 months (mean, 15.8 months). Prostate acid phosphatase and gamma-seminoprotein remained normal between 3 and 15 months after the administration but became elevated due to recurrence of progression after 18 months or more in some patients. Blood testosterone, luteinizing hormone, and follicle stimulating hormone decreased while blood cortisol increased. Therefore, estrogen was acting effectively. Side effects were observed in 56.9% of the patients, the most frequent being mazoplasia in 33 patients (45.8%), and cardiovascular complications and apoplexy in 11 patients (15.3%). Estracyt was effective for untreated prostatic carcinoma but the problems such as recurrence of progression and side effects require further examination.

Adenocarcinoma↗
PubMed1990

Evaluation of countermeasures for reduction of mouse airborne allergens.

Three kinds of countermeasures for reduction of mouse airborne allergens were evaluated with use of an air sampler and immunochemical methods. Mouse cages and the sampler were placed inside a flexible-film isolator, and concentrations of mouse major allergens in the air were measured. The levels of the airborne allergens, prealbumin and albumin, generated by 10 males, were 3,050 and 492 pg/m3, respectively. Those by 10 females were lower, 317 and 270 pg/m3, respectively. When mouse cages were covered with a filter cap, the airborne allergens inside the isolator were decreased by 90%. When corncob was used as bedding in place of wood shavings, the airborne allergens were decreased by 57 and 77%, respectively. Therefore, for reduction of mouse airborne allergens, we recommend using female mice, covering the cages with filter caps, and using corncob bedding.

Air Pollutants, Occupational↗
PubMed1989

Particle size of airborne mouse crude and defined allergens.

Laboratory animal allergy is a serious occupational diseases of many workers and scientists engaged in animal experimentation. Control measures depend upon characterization of allergens including airborne particles. This study measured the particle size of crude mouse urine and pelt aeroallergens generated in mouse housing rooms and compared them with mouse serum albumin, a defined major allergen. Allergens were detected by specific immunological methods. Most crude and defined allergens (74.5-86.4%) concentrated on a filter with a retention size greater than 7 microns. In distrubed air, allergen concentration increased 1.4 (albumin) to 5 (crude) fold and the proportion of small particles increased from 1.4% in calm air to 4.5% in distrubed air. This information on the generation and size distribution of aeroallergens will be important in the development of effective counter measures.

Air↗
PubMed1989

[Tissue distribution, inductive effect on liver enzymes and acute toxicity of 2,3,4,7,8-pentachlorodibenzofuran in Golden Syrian hamsters].

The hamsters have been known to be the least sensitive mammalian species to the acute toxicity of highly toxic polyhalogenated hydrocarbons such as 2,3,7,8-tetrachlorodibenzo-p-dioxin. In the present study, the tissue distribution, inductive effect of liver enzymes and acute toxicity of 2,3,4,7,8-pentachlorodibenzofuran (PenCDF) in male Golden Syrian hamsters were examined. The highest content (about 48% of dose) of PenCDF was found in the liver 5 days after a single i.p. dose of 1.0 mg/kg. The amount ranging about 5 to 10% of dose was also distributed to mesentery, skin and muscle. In liver, the distribution of PenCDF was just parallel to that of cytochrome P-450 (P-450), marker enzymes of liver endoplasmic reticulum, suggesting that PenCDF binds to P-450. The mode of inductive effects of PenCDF in hamsters was 3-methylcholanthrene-type as reported previously in rats. However, the typical enzymes such as benzo(a)pyrene 3-hydroxylase and DT-diaphorase were induced to a relatively less extent than did in rats. In hamsters pretreated with PenCDF at a dose of 0.5 mg/kg, the potent atrophy of thymus and the 3-fold increase of liver lipid peroxide were observed, whereas the body weight gain was not suppressed at all. These results suggest that the induction of liver enzymes and the atrophy of thymus might not be the direct cause of PenCDF-induced lethality in hamsters.

Animals↗
PubMed1989

[Studies on distribution, excretion and subacute toxicity of squalane in dogs].

In the previous papers, we demonstrated, by using rats, that squalane (2,6,10,15,19,23-hexamethyltetracosane) could stimulate the fecal excretion of 2,3,4,7,8-pentachlorodibenzofuran, which was regarded as the most important etiologic agent of yusho among PCB and PCDF congeners found in the causal rice oil. We also reported that, in rats, squalane was not essentially absorbed from the gastrointestinal tract, and did not show any appreciable side effects during the 3-month treatment. In the present paper, we have investigated the distribution, excretion and subacute toxicity of squalane in beagle dogs. The fecal excretion of squalane accounted for about 83% of dose during the initial 2 days after administration at a single oral dose of 1,200 mg/kg to male dogs. On day 3, absorbed squalane was mostly distributed to the hair and the skin, and the concentrations in these tissues were decreased on day 6. These results suggested that most of squalane administered orally was not absorbed from the gastrointestinal tract, but a part was absorbed and excreted through the hair. In addition, squalane distributed into the liver was found to be eliminated rather slowly. A long-term (13-week) treatments with squalane orally at doses of 400 mg/kg/day or 1,200 mg/kg/day in male and female dogs, resulted also in accumulation of squalane in the liver at a level of about 3% (400 mg/kg) or about 6% (1,200 mg/kg) of the daily dose. This accumulation of squalane in the liver was highest among all the tissues. Nevertheless, no appreciable toxic signs were observed in the serum biochemical tests and the hepatic functional test for squalane groups. Therefore, squalane accumulating in the liver, did not seem to disturb the hepatic physiological functions. It was suggested also in a long-term treatment that the skin and the hair played the most important role in the elimination of squalane. In conclusion, the present studies on subacute toxicity tests suggested that squalane did not give any significant toxic effects on dogs as well as rats.

Animals↗
PubMed1989

Evaluation of dust respirators for elimination of mouse aeroallergens.

The efficiency of various dust respirators for eliminating mouse allergens [mouse urine proteins (MUP), pelts proteins (MPP) and serum albumin (MSA)] were evaluated with use of low-volume air samplers and immunochemical methods. Three kinds of dust respirators from one manufacturer which have different efficacy in the exclusion of dust particles were put on the fiber glass filter in each air sampler. Then the air in a mouse housing room was sampled. The allergens passed through the respirators, were trapped in the fiber glass filters, and then extracted from the filters. The allergens of MUP and MPP in the extract were measured by an inhibition method of fluorometric enzyme-linked immunosorbent assay (ELISA) for IgE antibody and those of MSA measured by a fluorometric sandwich ELISA. The respirator with the lowest capability of exclusion was found to eliminate 65-86% of respective allergens. The other two respirators with higher powers eliminated 98% of MUP. MPP and MSA were eliminated to undetectable levels through these respirators. This study provided a means for the evaluation of dust respirators for animal aeroallergens.

Air Pollution↗
PubMed1988

Formation of gamma-amino-beta-hydroxybutyric acid from 2-hydroxyputrescine in rat brain.

gamma-Amino-beta-[3H]hydroxybutyric acid ([3H]-GABOB) was formed in rat brain from 2-[3H]-hydroxyputrescine that had been chemically synthesized from 2-oxoputrescine and [3H]sodium borohydride. After the injection of 2-[3H]hydroxyputrescine into the lateral ventricle of a rat brain, the rat was killed and then the brain was removed. [3H]GABOB in the brain was identified by a combination of ion-exchange chromatography, high-voltage paper electrophoresis, and recrystallization of the radioactive compound with authentic GABOB.

Animals↗
PubMed1988

[An epizootic Staphylococcus infection in a nude mouse colony].

An epizootic of Staphylococcus infection causing abscesses was encountered in a small-scale breeding colony of nude mice of BALB/c background. The incidence of abscess was sporadic and mostly nude (nu/nu) mice aged over 3 months were affected. Staphylococcus aureus was isolated from the face, oral cavity, and feces of almost all nu/nu and heterozygous (nu/+) mice in the colony. After a prolonged time period, up to 10 to 14 months of age, almost all the S. aureus-carrying nu/nu mice produced abscesses and eventually died. Athymicity of the host seemed to be a prerequisite for the abscess formation since nu/+ mice were spared from the lesions. Also, transfer of immunocompetent spleen cells cured the abscesses of the affected nude mice.

Abscess↗
PubMed1988

Metabolic fate of indeloxazine hydrochloride: alpha-glucoside formation in rats.

1. After oral administration of indeloxazine hydrochloride ((+/-)-2-[(inden-7-yloxy)methyl]morpholine hydrochloride) to rats, two conjugates, which were labile to alpha-glucosidase hydrolysis but refractory to beta-glucosidase, were isolated from the urine. 2. Mass spectral and n.m.r. analyses confirmed that these conjugates were alpha-D-glucopyranosides of M-2 (trans-4-(2-morpholinylmethoxy)-1,2-indandiol) and M-3 (trans-6-[[(1,2-dihydroxy-4-indanyl)oxy]-methyl]-3-morpholinone). 3. These are probably the first examples of foreign compounds conjugated with glucose in the alpha-configuration.

Animals↗
PubMed1988

Enhanced faecal excretion of 2,3,4,7,8-pentachlorodibenzofuran in rats by a long-term treatment with activated charcoal beads.

1. The effect of activated charcoal beads on the faecal excretion of 2,3,4,7,8-pentachlorodibenzofuran (PenCDF), a causal agent of yusho, which accumulates in the body, was studied for 12 weeks in rats. 2. Diets supplemented with 1% and 5% activated charcoal beads stimulated faecal excretion of PenCDF about 2- and 4-fold, respectively. The concentration of PenCDF in liver, the major storage site, was decreased significantly and dose-dependently by the treatment. 3. The charcoal bead treatment decreased the extent of fatty liver, thymic atrophy, and induction of hepatic benzo[a]pyrene hydroxylase.

Animals↗