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Biomedical subjects

K Hirota

Publications and source records attributed to K Hirota.

At least 325 records · Page 18Linked to original sources
PubMed1993

[Clinical study on total intravenous anesthesia with droperidol, fentanyl and ketamine--20. Summary of three thousand cases and the future of this anesthetic method].

Total intravenous anesthesia with droperidol, fentanyl and ketamine (DFK) was given to over three thousand patients during four years from April 1989 through March 1993. The patients ranged in age from three months to eighty seven years. They underwent surgical, orthopedic, gynecological, thoracic, plastic and otolaryngeal surgeries, but patients who underwent craniotomy and obstetric operations were excluded. None of them developed any serious complications primarily due to DFK. DFK has many advantages such as the broad safety margin for three agents employed in DFK, no accident by N2O, no air pollution, empty bowels, no increase in middle ear pressure etc, while this has disadvantages such as high blood pressure, slow awakening from anesthesia and unpleasant dreams. Calcium channel blockers are very effective for antagonizing high blood pressure, and rapid recovery from anesthesia can be easily obtained by reducing ketamine dose given and also by application of epidural block. Intraoperative dreams may be avoided by concomitant use of benzodiazepines. Thus we are convinced that DFK can be a good as well as convenient anesthetic method for clinical anesthesia.

Adolescent↗
PubMed1993

Protective effect of E3330, a novel quinone derivative, in galactosamine-induced hepatitis in rats.

The effect of E3330 ((2E)-3-[5-(2,3-dimethoxy-6-methyl-1,4-benzoquinoyl)]-2-nonyl-2-++ +propenoic acid), a novel quinone derivative, was studied in the galactosamine-induced hepatitis model in F344 rats, in which endogenous endotoxin is believed to play a critical pathogenetic role. Subcutaneous injection of 300 mg/kg of galactosamine into rats resulted in liver injury. Oral treatment with E3330 (10-100 mg/kg) 1 hr after galactosamine challenge attenuated the liver injury. E3330 was also effective when administered p.o. 6 or 12 hr after galactosamine challenge. Subcutaneous injection of 1000 mg/kg of galactosamine into rats resulted in more severe liver injury with endotoxemia. The plasma endotoxin was detected 24 to 48 hr after the galactosamine challenge. The time course of increase in plasma endotoxin level was in good agreement with that in plasma aminotransferase activity. E3330 (100 mg/kg) significantly attenuated the liver injury, but did not affect the endotoxin level. Exogenous administration of endotoxin enhanced the hepatotoxicity of galactosamine. Pretreatment with E3330 also protected rats from severe liver injury induced with endotoxin plus galactosamine. These results suggest that E3330 may exert its hepatoprotective effects through inhibition of an effect of endotoxin in galactosamine-induced hepatitis in rats.

Animals↗
PubMed1993

[Clinical study of total intravenous anesthesia with droperidol, fentanyl and ketamine--effects of nicardipine, diltiazem and nifedipine on intraoperative hypertension].

Effects of Ca ion channel blockers, nicardipine, diltiazem and nifedipine on intraoperative hypertension were evaluated clinically in ninety surgical patients who received various surgical procedures under total intravenous anesthesia with droperidol, fentanyl and ketamine. When the systemic blood pressure exceeded 160 mmHg systolic at least for ten minutes, even though they received a total dose of 10-15 micrograms.kg-1 of fentanyl, one of the following three antihypertension drugs was administered:nicardipine 0.5-1.0 micrograms i.v., diltiazem 5-10 mg i.v. and nifedipine 5-10 mg intranasally. The effects were evaluated by measuring the systemic blood pressure, heart rate and rate pressure product, before the administration as well as 5, 15, 20 and 30 minutes after the administration. Following the injection of the drug a significant 10-20% reduction in the mean systemic blood pressure was observed in the nifedipine group, while less decrease was observed in the diltiazem and nicardipine groups. The mean heart rate in the nifedipine group increased slightly, while a slight decreases was observed in the other two groups. Therefore the rate pressure product was reduced significantly in three groups, but there was no significant difference among them. No adverse episodes such as ischemic changes on E.K.G. and deterioration of the cardiovascular system were encountered in any patients. We conclude that any of these drugs, particularly nifedipine would be appropriate to control hypertension during total intravenous anesthesia with droperidol, fentanyl and ketamine.

Anesthesia, Intravenous↗
PubMed1992

Protective effects of E3330, a novel quinone derivative, on galactosamine/tumor necrosis factor-alpha-induced hepatitis in mice.

Oral pretreatment with E3330, a novel quinone derivative, attenuated liver injury induced with tumor necrosis factor-alpha in galactosamine-sensitized mice. Tumor necrosis factor-alpha is known to induce inflammatory mediators such as leukotrienes and prostanoids. An in vitro study showed that E3330 inhibited the generation of leukotriene B4 and thromboxane B2, but enhanced prostaglandin E2 generation from rat peritoneal exudate cells stimulated with the Ca(2+)-ionophore, A23187. These findings suggest that the protective effect of E3330 on galactosamine/tumor necrosis factor-alpha hepatitis is due at least in part to its inhibition of the generation of leukotrienes. The inhibition of thromboxane B2 generation or the enhancement of prostaglandin E2 generation by E3330 may also contribute to its hepatoprotective effect.

Animals↗
PubMed1992

Sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for (anti-human T-cell leukemia virus type I) IgG in serum using recombinant gag p24(14-214) as antigen.

A sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) for (anti-human T-cell leukemia virus type I) IgG (anti-HTLV-I IgG) in serum using recombinant gag p24(14-214) of HTLV-I is described. The recombinant gag p24(14-214) is soluble in the absence of detergents and allows the use of enzymes other than horseradish peroxidase as a label in the assays. The usefulness of recombinant gag p24(14-214) was examined with 305 sera characterized by other methods including gelatin particle agglutination, enzyme-linked immunosorbent assay (ELISA) using HTLV-I, and Western blotting. This assay was more sensitive than other methods using HTLV-I as antigen. The specificity could be tested by preincubation of test serum with excess of the recombinant protein. Most of negative and positive sera were discriminated. However, some results appeared to be false-positive or false-negative, and recombinant gag p24(14-214) was suggested to be useful, when used with other recombinant proteins and/or peptides, for improving the reliability of serodiagnosis by separately demonstrating antibodies against as many different epitopes of HTLV-I as possible. Anti-HTLV-I IgG in test serum, which had been incubated with excess of inactive beta-D-galactosidase to eliminate interference by anti-beta-D-galactosidase antibodies, was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-recombinant gag p24(14-214) conjugate and recombinant gag p24(14-214)-beta-D-galactosidase conjugate. The complex formed consisting of the three components was trapped onto polystyrene balls coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation Studies as Topic↗
PubMed1992

Prospective study on maternal, intrauterine, and perinatal infections with cytomegalovirus in Japan during 1976-1990.

Since 1976, sera obtained serially from 10,218 pregnant women during the first, second, and third trimesters of gestation and cord sera were tested for CMV complement-fixing (CF) and immunofluorescent (IF) antibodies. CMV IgG-IF antibody was positive in 9,735/10,218 (95%) in the first trimester, and a significant rise of CF antibodies during pregnancy was found in 70/9,206 (0.76%) of the seropositive group and in 5/438 (1.14%) of the seronegative group. IgM antibody was found in 6/9,206 (0.06%) of seropositive women during the first trimester and in 7/70 (10.0%) of seropositive mothers with CF antibody rise and in 4/5 of seroconverted mothers of the seronegative group, suggesting that the incidence of primary infection with CMV during pregnancy was approximately 1% of susceptible women. All the mothers with immune response had infants with neither viruria nor IgM antibody in the cord blood, whereas seropositive mothers without an immune response had infants with viruria (7/1,826; 0.4%) or with IgM antibody in the cord blood (6/9,136; 0.06%). None of these 13 babies, shedding CMV or with IgM IF antibody, had physical or mental retardation. CMV IgG-IF antibody was present in almost 80% of infants between 7 and 12 months of age in 1988, suggesting that perinatal or postnatal CMV infection may occur in infants born to seropositive mothers in 70-80% of pregnancies.

Antibodies, Viral↗
PubMed1992

Epidemiological survey of Streptococcus mutans in a group of adult patients living in Pisa (Italy).

An epidemiological investigation was carried out to evaluate the prevalence of Streptococcus mutans in a group of 134 adult patients. Markedly higher frequency of isolation was observed in caries-active subjects than in caries-inactive or caries-free subjects, indicating a significant association between the prevalence of the microorganism and the caries status. Moreover, the presence of the microorganism appeared to have a significant association with the extent of caries experience evaluated by the DMF score. These findings are in agreement with those reported previously for school children in other areas of Italy. Isolation of S. mutans was compared among patients groups with different caries activity in relation to culture times of dental plaque samples in a transport medium (Colorimetric Broth Medium). S. mutans was most frequently isolated from caries-active subjects when the medium was incubated for 48 h after inoculation with dental plaque samples.

Adolescent↗
PubMed1992

Production of interleukin 8 by cultured synovial cells in response to interleukin 1 and tumor necrosis factor.

Both interleukin 1 alpha (IL-1 alpha) and tumor necrosis factor alpha (TNF alpha) stimulated the production of interleukin 8 (IL-8) by synovial cells in time and dose dependent manners. Enhanced chemotactic activity of polymorphonuclear cells (PMN) in culture supernatants of synovial cells was neutralized with anti-IL-8 antibody, thus showing synovial cells to be capable of secreting IL-8 which may contribute to PMN accumulation in rheumatoid inflamed joints.

Cells, Cultured↗
PubMed1992

Suppressive effects of E3330, a novel quinone derivative, on tumor necrosis factor-alpha generation from monocytes and macrophages.

E3330 [(2E)-3-[5-(2,3-dimethoxy-6-methyl-1,4-benzoquinoyl)]-2-nonyl-2- propenoic acid], a novel synthesized hepatoprotective compound, has suppressive effects on tumor necrosis factor-alpha (TNF-alpha) generation from monocytes/macrophages in vitro. E3330 (1-100 microM) reduced lipopolysaccharide (LPS, 10 mg/ml or 1 microgram/ml)-induced TNF-alpha generation from rat resident and Propionibacterium acnes (P. acnes)-elicited peritoneal macrophages, rat and human monocytes, rat Kupffer cells, and splenic mononuclear cells in a concentration-dependent manner. E3330 also (1-100 microM) suppressed TNF-alpha generation stimulated with egg-albumin immune complex in rat P. acnes-elicited peritoneal macrophages. Northern blot analysis showed that LPS-induced expression of TNF-alpha messenger RNA (mRNA) in human blood monocytes was suppressed by E3330. These findings indicate that E3330 has a suppressive effect on TNF-alpha generation from monocytes/macrophages, regardless of origin or species, and this effect is based in part on the suppression of TNF-alpha mRNA expression.

Animals↗
PubMed1992

Brainstem auditory evoked potentials during procaine toxicity in dogs.

Although the toxic effect of local anaesthetics on the activity of cerebral cortex has been extensively studied, little is known about their toxic effect on brainstem. Accordingly, the influence of procaine on brainstem auditory evoked potentials (BAEPs) and on the electroencephalogram (EEG) was observed in 15 dogs. After the administration of procaine (15 mg.kg-1, i.v.), the amplitudes of wave I (1.88 +/- 0.56 vs 2.06 +/- 0.61 microV, mean +/- SD) and wave II (1.91 +/- 0.41 vs 2.06 +/- 0.46 microV) in BAEPs increased (P less than 0.05), while the amplitudes of wave III (0.97 +/- 0.27 vs 0.81 +/- 0.24 microV), wave IV (1.15 +/- 0.43 vs 0.85 +/- 0.29 microV) and wave V (1.04 +/- 0.46 vs 0.92 +/- 0.41 microV) were decreased (P less than 0.05), and both the I-III inter-peak latency (1.57 +/- 0.04 vs 1.70 +/- 0.07 msec) and III-V inter-peak latency (2.15 +/- 0.09 vs 2.35 +/- 0.12 msec) were prolonged (P less than 0.01). The EEG changed from an awake pattern to seizure activity. These results suggest that the electrical activity of the brainstem auditory pathway is suppressed even when the cerebral cortex is in an excitatory state at the convulsive stage of procaine toxicity.

Animals↗
PubMed1992

Effect of diet and lifestyle on bone mass in Asian young women.

The relationship between bone mineral content (BMC) divided by bone width (BW) and diet and lifestyle in early adulthood were investigated from the view point of preventing osteoporosis at a young age in Asian women. BMC/BW of 161 healthy Asian women aged 19-25 y were measured by single-photon absorptiometry. Current and past dietary habits and physical activity were also studied. BMC/BW varied from 0.21 to 0.48 g/cm2. Bone density correlated well with dietary habit from infancy to the present especially with calcium and past physical activity. These two factors showed additive effects on BMC/BW. In multiple-regression analysis, liking sports, body mass index, no milk intake in childhood, protein intake, frequency of dieting, and skipping meals were contributors to bone density and predictive of 23% of the variability in BMC/BW in the total group. The multiple-regression coefficient was 0.518. Smoking, drinking, and duration of sunbathing might have no effect on BMC/BW in early adulthood.

Adult↗
PubMed1992

Effects of protein intake on immune parameters in mice surviving streptococcal infection.

Groups of mice were fed for 2 weeks on isocaloric diets containing 5, 7, 20 and 40% (w/w) casein, respectively, then injected intraperitoneally with group B streptococci, and observed for their survival rates. The mice fed 7% or 20% casein had lower mortalities than those fed 5% or 40% casein. In order to explain the different survival rates, other groups of mice were fed on the experimental diets and examined for the number of leukocytes in the blood, of spleen cells and thymocytes, for IgG and IgM antibody titres to the streptococci, for haemolytic titres of sera, the amount of complement component 3 (C3), for chemiluminescence and opsonic activity of peritoneal exudate cells (PEC) and spleen cells (SP), production of superoxide anion from PEC and SP, and production of immunoglobulins from cultured SP. After 2 weeks on a 7 or 20% casein diet mice showed increased serum levels of IgM antibodies reactive with the whole bacterial cells on days 3-5 when they were immunised with a sublethal dose of group B streptococci. The mice fed on the 7% casein diet also showed a higher C3 titre than the other diet groups when assayed by enzyme immunoassay. Furthermore, opsonophagocytic activity was highest when PEC or SP taken from mice on the 20% case in diet were incubated with radiolabelled microorganisms in the presence of fresh serum taken from the 7% casein group. The production of superoxide anions from PEC and SP was lowest in the mice fed on 5% casein when activity was expressed as nano-mol per animal. It is suggested from these results that the greater activity of phagocytic cells in the presence of increased amounts of C3 and IgM explains the heightened resistance in the mice fed on a 7% casein diet, and that suppressed opsonophagocytic activity resulting from the decreased number of leukocytes in the blood and other phagocytic cells explains the lowest resistance in the 5% casein group. However, mice fed on a 40% casein diet showed all these immunological parameters untouched, and their lowered resistance could not be explained. Different factors seem to be operative in them.

Animals↗
PubMed1992

Binding sites for interleukin-6 in the anterior pituitary gland.

Interleukin-6 (IL-6) binding site in the rat anterior pituitary gland was characterized using radioiodinated human recombinant (hr) IL-6. Results showed that the anterior pituitary gland contained 170 binding sites per cell of a single class with a dissociation constant of 2.7 x 10(-9) M. The binding of 125I-hrIL-6 to the rat anterior pituitary gland was competitively inhibited by unlabeled hrIL-6, but not by hrIL-1 alpha, hrIL-1 beta, hrIL-2 or hr-interferon-gamma, indicating these binding sites are specific for IL-6. We also demonstrated mouse IL-6 receptor gene expression in the rat anterior pituitary gland by Northern blot analysis. Furthermore, the IL-6 receptor was detected on human gonadotrophs by the double immunofluorescence method. Our findings demonstrate the presence and expression of IL-6 binding site in the rat anterior pituitary gland and the presence of IL-6 binding site on human gonadotrophs, suggesting the important role of IL-6 binding site in pituitary hormone release in both species.

Animals↗
PubMed1992

Atrial and brain natriuretic peptides enhance dopamine accumulation in cultured rat hypothalamic cells including dopaminergic neurons.

Dopamine accumulation in hypothalamic cells by atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) was analyzed using newborn rat hypothalamic cells in culture. Both ANP and BNP caused a dose-dependent increase in [3H]-dopamine accumulation in the cells. ANP increased [3H]-dopamine accumulation significantly within 20 min. The effects of ANP and BNP on dopamine accumulation paralleled an increase in intracellular cGMP concentration. (Bu)2-cGMP and sodium nitroprusside, a stimulator of the soluble form of guanylate cyclase, also enhanced [3H]-dopamine accumulation. ANP had no effect on efflux of [3H] radioactivity after [3H]-dopamine uptake. These results suggest that a change in cGMP is one of the intermediate steps in dopamine accumulation in hypothalamic cells by ANP and BNP.

Animals↗
PubMed1992

Effects of halothane on electrophysiologic properties and cyclic adenosine 3',5'-monophosphate content in isolated guinea pig hearts.

We studied the effects of halothane on the electrophysiologic and biochemical properties of both Langendorff perfused hearts and single ventricular myocytes isolated from guinea pigs. Isometric contractions of left ventricles in perfused hearts, elicited by atrial pacing, decreased to 14% of control after exposure to 2% halothane-equilibrated perfusate. Subsequently the slow inward Ca2+ current (ICa) was recorded in isolated myocytes with a whole cell voltage clamp technique. ICa, recorded in response to 100-ms depolarizations from -40 mV to 0 mV, was decreased by 2% halothane to 28.4% of control. Halothane-induced ICa depression did not exhibit use dependency. To define a possible site at which halothane acts, we measured the cyclic adenosine 3',5'-monophosphate (cAMP) content of single ventricular myocytes using a radioimmunoassay. Two percent halothane decreased myocardial cAMP content to 68.9% of control. Further addition of dibutyryl cAMP (10(-3) mol/L) partially reversed the depressed contractility during 2% halothane administration in perfused hearts. In conclusion, the present study demonstrated that the decrease of myocardial cAMP by halothane was due to a direct action, at least partly, and not to other factors such as catecholamines, and suggested that the decreases in contractility and ICa were induced possibly through the decrease in cellular cAMP.

Animals↗
PubMed1992

Effects of sodium L-lactate and sodium racemic lactate on intraoperative acid-base status.

Lactated Ringer's solution is frequently used to avoid metabolic acidosis during fluid resuscitation. The standard lactated Ringer's solution contains racemic lactate, an equal mixture of the D- and L-stereoisomers. We investigated whether sodium L-lactate or sodium racemic lactate (DL-lactate) is more effective for increasing buffering capacity in body fluids. For the purpose of this comparison, Ringer's solutions containing no lactate, sodium L-lactate, or racemic lactate at a concentration of 84 mEq/L (three times more than the ordinary level) were infused in patients under general anesthesia during tympanoplasty. Although differences occurred among the three groups in blood concentrations of L-lactate, D-lactate, and the L-lactate/pyruvate ratio, no differences occurred between the two lactate groups in either bicarbonate ion concentration or base excess. The amount of buffering capacity increased significantly in both lactate groups, compared with preinfusion levels, and was more than the values in the nonlactated Ringer's solution group. We conclude that sodium racemic lactate is metabolized at nearly the same rate as that of sodium L-lactate.

Acid-Base Equilibrium↗