PubMed Health⌕ Search

Biomedical subjects

H Kito

Publications and source records attributed to H Kito.

At least 73 records · Page 4Linked to original sources
PubMed1990

Mechanism of antimutagenicity of aquatic plant extracts against benzo[a]pyrene in the Salmonella assay.

The mechanism of antimutagenicity of water extracts of grass-wrack pondweed (Potamogeton oxyphylus Miquel), curled pondweed (Potamogeton crispus L.) and smartweed (Polygonum hydropiper L.) towards benzo[a]pyrene mutagenicity in Salmonella typhimurium was investigated. The antimutagenic components in the aquatic plants were water-soluble, heat-resistant and had a high molecular weight; chlorophyll did not play an important role.

Benzo(a)pyrene↗
PubMed1990

Inhibitory action of peony root extract on the mutagenicity of benzo[a]pyrene.

The inhibitory effects of peony root extract on the mutagenicity of benzo[a]pyrene (B [a]p) have been investigated in the Salmonella typhimurium reversion test. Four kinds of experiments were performed: direct chemical reaction (1) between peony root extract and B [a]p, and (2) between peony root extract and active metabolite(s) of B [a]p, (3) inhibition of metabolic processes of B[a]p with S9 mix, and (4) inhibition of activation on mutagenicity. Peony root extract interfered with the action of enzymes in the S9 mix, and inactivated the activity of B[a]p metabolites. The bio-antimutagenic effect was assayed by reversion in Salmonella typhimurium TA98 and TA100.

Benzo(a)pyrene↗
PubMed1990

Prevalence of metallothioneinuria among the population living in the Kakehashi River basin in Japan--an epidemiological study.

An epidemiological study to evaluate cadmium-induced renal dysfunction by urinary metallothionein levels was carried out in an environmentally-exposed Japanese population. The study population consisted of 3168 men and women from a cadmium-polluted area who were 50 years and older and 291 individuals from a non-polluted area. The mean metallothionein levels in urine of the control population were 138.2 +/- 2.1 and 198.6 +/- 1.9 microgram/g creatinine for men and women, respectively. The corresponding values for the cadmium-exposed population were 157.8 +/- 2.2 and 248.0 +/- 2.2. The 97.5% upper limits for men in the control population was determined to be 638 and for women 693 microgram MT/g creatinine. Based on these values as the cut-off levels, the prevalence of metallothioneinuria was calculated to be 4.6% in men and 8.4% in women from the cadmium-polluted area. Further selection of the population, based on life-time residence in the polluted area accompanied with the consumption of cadmium-containing rice, showed an even greater prevalence of metallothioneinuria: 5.4% in men and 10.9% in women of all ages. The prevalence of metallothioneinuria increased with age and duration of residence in the polluted area. These results suggest that metallothioneinuria can be used as an indicator of renal dysfunction due to environmental cadmium exposure.

Age Factors↗
PubMed1990

Enhancement of the mutagenicity of Trp-P-1, Trp-P-2 and benzo[a]pyrene by bupleuri radix extract.

Boiling-water extract of Korean-Saiko (Bupleuri Radix, from South Korea, Bupleurum falcatum L.) enhanced the mutagenic activity of Trp-P-1, Trp-P-2 and benzo[a]pyrene with S9mix. The boiling-water extract was fractionated with ether and then n-BuOH. Both the ether and the n-BuOH fractions also enhanced mutagenicity of Trp-P-1, respectively. The n-BuOH fraction was separated into seven fractions by silica gel chromatography and the chloroform eluate had the strongest enhancing effect on the mutagenic activity of Trp-P-1 with S9mix. The chloroform eluate fraction was further separated into five spots by thin-layer chromatography. Two of the spots had the strongest enhancing effect on the mutagenic activity of Trp-P-1. Since saikosaponin is a well known component in Bupleuri Radix, the effects of its existence were tested and saikosaponins a and c were found. The enhancement activity of saikosaponin a was very weak. The effective components are now being studied.

Animals↗
PubMed1990

Surfactant replacement therapy with a single postventilatory dose of a reconstituted bovine surfactant in preterm neonates with respiratory distress syndrome: final analysis of a multicenter, double-blind, randomized trial and comparison with similar trials. The Surfactant-TA Study Group.

The effects of a single dose of surfactant TA were assessed in premature neonates (birth weight 750 to 1749 g) with respiratory distress syndrome (RDS) in a multicenter, double-blind, randomized clinical trial. Only neonates with surfactant deficiency and without ultrasonographic evidence of intracranial hemorrhage greater than or equal to grade II were enrolled. Fifty-four patients received surfactant (100 mg of phospholipid per kilogram of body weight) and 46 patients received an air placebo within 8 hours of life. Treatment with this surfactant resulted in a significant reduction in the severity of RDS with a concomitant increase in the proportion of neonates with mild disease. The frequency of pulmonary interstitial emphysema and of pneumothorax was significantly lower in treated neonates compared with control neonates (2% vs 26%, P = .0008, and 7% vs 39%, P = .0004, respectively). The frequency of intracranial hemorrhage was significantly lower in the surfactant group compared with the control group (20% vs 54%, P = .0008) and was also reduced for the smallest neonates in the surfactant group (13% vs 73%, P = .00008). When categorized according to severity of intracranial hemorrhage and severity of bronchopulmonary dysplasia, the surfactant group was at a significant advantage (adjusted Cochran-Mantel-Haenszel X2 = 10.72, P less than .001 and X2 = 4.43, P = .036, respectively). The proportion of neonates surviving without intracranial hemorrhage and/or bronchopulmonary dysplasia was 63% in the surfactant group vs 26% in the control group (P = .0004); as for the smallest neonates, it was 58% in the surfactant group vs 4% in the control group (P = .0002). There were no differences between the groups with respect to the frequency of patent ductus arteriosus (46% vs 37%), pulmonary hemorrhage (6% vs 7%), necrotizing enterocolitis (0% vs 2%), sepsis (4% vs 2%), retinopathy of prematurity (13% vs 22%), or death (15% vs 22%). It is concluded that treatment with the single-dose surfactant regimen used in this study reduces the severity of respiratory distress during the 48 hours after treatment and decreases the major pulmonary morbidity and intracranial hemorrhage in premature neonates with RDS. Further studies are needed to determine whether (1) treatment at birth or as soon as after RDS is diagnosed and (2) the use of multiple dose of this surfactant would result in any additional benefits.

Bronchopulmonary Dysplasia↗
PubMed1990

[Influences of intra-aortic balloon pumping on superior mesenteric flow dynamics].

The influences of intra-aortic balloon pumping (IABP) on arterial flow of the superior mesenteric artery were assessed by Doppler echocardiography. The subjects were 13 patients postoperatively, requiring IABP support to control low cardiac output state, in which distal aspects of balloons were distal to the superior mesenteric artery. Superior mesenteric flow velocity integral in systole (IntS) and that in diastole (IntD) were measured from superior mesenteric flow pattern, and the sum of IntS and IntD (IntS + IntD) was calculated ON and OFF balloon pumping (IABP ON-OFF test). The same parameters were obtained with balloon inflating on every other beat (IABP 1:2 test); the cardic cycle with balloon assist was defined as "1:2 ON", and that without balloon assist was defined as "1:2 OFF". 1) IABP ON-OFF test. IABP increased IntS from 7.07 +/- 2.56 cm to 9.20 +/- 3.19 cm (p less than 0.05), IntD from 3.00 +/- 1.18 cm to 3.62 +/- 1.40 cm (p less than 0.05), and IntS + IntD from 10.07 +/- 3.48 cm to 12.82 +/- 4.04 cm. Cardiac output increased from 3.89 +/- 1.34 l/min to 4.24 +/- 1.64 l/min with IABP support. The increments in IntS, IntD and IntS + IntD with IABP are attributed, to a large extent, to an increase in cardiac output. 2) IABP 1:2 test. Without balloon inflation, IntS increased (1:2 ON; 7.16 +/- 2.91 cm, 1:2 OFF; 8.41 +/- 3.30 cm, p less than 0.05), and IntD decreased (1:2 ON; 3.51 +/- 1.60 cm, 1:2 OFF; 2.33 +/- 1.25 cm, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Behavioral state distribution throughout 24-h video recordings in preterm infants at term with good prognosis.

Behavioral state distribution in 19 preterm infants at term with good developmental prognosis was studied by 24-h video recordings. The preterm infants of shortest gestation had longer time awake and this was concentrated in the daytime. On classifying behavioral states by Prechtl's criteria, the preterm infants had a smaller amount of state 1 than healthy term infants; but a similar amount of state 5 in awake time. Preterm infants were thought to have accelerated development in terms of diurnal sleep-awake rhythm, and decelerated development in terms of the content of sleep manifested by the amount of state 1.

Birth Weight↗
PubMed1989

Computed tomographic findings in children with spastic diplegia: correlation with the severity of their motor abnormality.

Computed tomographic findings of 46 children with spastic diplegia examined at nine months to three years of age corrected for preterm births were analyzed. Both the size of the lateral ventricles measured by the width of the anterior horns, and the volume of the extracerebral low-density areas were enlarged in some patients. Both enlargements did not, however, correlate to the severity of the motor abnormality in the patients. The low-density areas of the periventricular white matter, especially adjacent to the trigone, were reduced in many children, probably due to the atrophy of the cerebral white matter having periventricular leukomalacia. The anterior expansion of the white matter reduction from the trigone corresponded to the severe motor abnormality in the children with spastic diplegia.

Atrophy↗
PubMed1988

Computed tomographic findings in full-term infants with good prognosis.

To determine the normal neonatal computed tomographic (CT) findings, 121 CT scans of term infants with some neurological symptoms in the neonatal periods and a later good prognosis were studied. The majority of the neonates had asymmetric skulls with backward protrusion of the left occipital bone. In early neonates, the ventricles were small and straight high density lines were commonly seen in the posterior longitudinal cerebral fissure. In many, the left posterior horn was larger than the right one. Periventricular low density areas in the anterior and the posterior horns were noticed. The basal ganglia and the thalamus showed homogeneous density that was the same as that of the cerebellum. About one-third of the neonates had extra-cerebellar low density areas.

Aging↗
PubMed1987

[Experimental study on splenomegaly after partial hepatectomy].

Using 70% hepatectomized rat, morphological and functional changes of the spleen after partial hepatectomy were investigated. The results were as follows; 1. The weight of the spleen was maximum on the 7th and 10th day after partial hepatectomy and still high on the 14th day. There was no definite relationship between the weight of the spleen and the portal pressure. 2. Histologically and morphometrically, there was neither congestion nor enlargement in the red pulp after hepatectomy. Until the 3rd day after hepatectomy, the white pulp was developed. From the second day through the 14th day the marginal zone was enlarged. 3. The incorporation of 3H-thymidine into DNA of the spleen cells increased from the first day through the 7th day after hepatectomy. By autoradiography the labeled cells were mainly large mononuclear cells. 4. Both macrophages phagocytizing carbon particles in the red pulp and endogenous peroxidase-positive macrophages in the marginal zone were increased on the third day but not on the 7th day after hepatectomy. 5. Studied by immunohistochemistry with monoclonal antibodies, both T and B cells in the spleen were increased after hepatectomy. 1 and 3 days after hepatectomy T cell zone was predominant, but 7 days after hepatectomy B cell zone was predominant. Most of cells in the marginal zone were B cells and they were increased on the 7th day after hepatectomy. These results suggest that the splenomegaly after 70% hepatectomy is due to not only portal congestion or increase of macrophages but increase of lymphocytes.

Animals↗
PubMed1986

Activity, cardiac and respiratory responses of blindfold preterm infants in a neonatal intensive care unit.

The purposes of the present study were to examine 24-h periods in the life of preterm infants incubated in a Neonatal Intensive Care Unit (NICU) using indices of activity, cardiac and respiratory responses, and to examine the effects of blindfolding incubated infants upon these behavioural indices. Ten healthy preterm infants were individually observed for 2 days a week for a 24-h period, using a continuous video recording system. Each infant was blindfolded with an eye-mask and a black head-cap for approximately equal to 10 h during a night out of the 2 days. Analyses on activity, cardiac and respiratory responses were done for (1) 20 min sampled from every other hour during the 2 days, and (2) for 1 h during the night, both a blindfolded day and unblindfolded, respectively. The results showed that activity was less and respiration rate lower when blindfolded than when unblindfolded. Respiration rate was also found to be stable when blindfolded.

Birth Weight↗
PubMed1986

Species difference of (2R,4R)-2-(o-hydroxyphenyl)-3-(3-mercaptopropionyl)-4-thiazolidinec arb oxylic acid (SA446) in inhibition of angiotensin converting enzyme.

A marked species difference was observed both in vitro and in vivo in the activity of SA446, an orally active inhibitor of angiotensin converting enzyme (ACE), as compared with that of captopril in five different animal species. The activity of SA446 in vitro in inhibiting plasma ACE correlated with the activity in vivo as determined by inhibition of the pressor response to angiotensin I (AI). SA446 was more potent as an inhibitor of AI response in dogs, cats and rabbits than in guinea pigs and rats. Furthermore, ACE activity in whole blood in vivo was inhibited by SA446, and the activity of SA446 was also more potent in dogs than in rats. The concentration of SA446 in the ultrafiltrate of blood (free form) was significantly higher in dogs than in rats, while no difference was observed in level of SA446 in the whole blood (free and protein-bound form) between these two species after intravenous injection. The binding rate of SA446 to plasma protein of rats in vitro was more than twice as high as that of dogs. These results suggest that the difference in the protein binding rate of SA446 is reflected in ultrafiltrate level and is one of the important components in defining the species difference in SA446 action.

3-Mercaptopropionic Acid↗
PubMed1986

Cadmium-binding protein (metallothionein) in carp.

When carp (Cyprinus carpio) were exposed to 5 and 30 ppm Cd in the water, the contents of Cd-binding protein, which has low molecular weight, increased in the hepatopancreas, kidney, gills and gastrointestinal tract with the duration of exposure. This Cd-binding protein was purified from hepatopancreas, kidney, gills, and spleen of carp administered 2 mg/kg Cd (as CdCl2), intraperitoneally for 6 days. Two Cd-binding proteins were separated by DEAE-Sephadex A-25 column chromatography. These proteins had Cd-mercaptide bond, high cysteine contents (ca. 29-34%), but no aromatic amino acids or histidine. From these characteristics the Cd-binding proteins were identified as metallothionein. By using antiserum obtained from a rabbit to which carp hepatopancreas MT-II had been administered, immunological characteristics between hepatopancreas MT-I, II and kidney MT-II were studied, and a slight difference in antigenic determinant was observed among them. By immunological staining techniques with horseradish peroxidase, the localization of metallothionein was investigated. In the nontreated group, metallothionein was present in the acinar cells of hepatopancreas and renal convoluted tubules. In the Cd-treated group (2 mg/kg IP daily for 3 days), metallothionein was present in the nuclei, sinusoids, and extracellular space of hepatopancreas, in addition to the acinar cells. Carp were bred in 1 ppm Cd, 5 ppm Zn solution, and tap water for 14 days, following transfer to 15 ppm Cd solution, respectively. The survival ratio was the highest in the Zn group followed by Cd-treated and control groups. The metallothionein contents increased in hepatopancreas and kidney in the order: Zn greater than Cd greater than control group.

Amino Acids↗
PubMed1984

Production of serotonin by a transplantable strain of histamine-producing primary gastric carcinoid of Mastomys natalensis.

Two biochemically distinguishable transplantable tumor strains (A and B) were established from a primary gastric carcinoid of Mastomys secreting histamine alone. Strain A in the third generation acquired a new ability to produce serotonin [5-hydroxytryptamine (5-HT)] and retained endocrine activities to produce both histamine and 5-HT through the following subpassages, whereas strain B (like the primary tumor) continued to produce histamine alone. The findings were further supported by the immunohistochemical demonstration of 5-HT-containing tumor cells in strain A after generation 3 and the absence of such cells in strain B and also by the ultrastructural demonstration of tumor cells containing pleomorphic secretory granules in strain A after the third generation but not in strain B. Sixteen samples of Formalin-fixed, paraffin-embedded primary gastric carcinoids of Mastomys were stained by the same immunohistochemical method for 5-HT detection. The positively stained tumor cells were demonstrated in 4 tumor samples, though they were scantily distributed in tumor parenchyma except for 1 metastasizing tumor. 5-HT-producing tumor cells appeared through many proliferative cycles of the deranged histamine-producing cells. The endocrinologic similarity was noted between this transplantable tumor strain and a specific type of gastric carcinoid in humans, and the possible histogenesis of the latter tumor was discussed on the basis of data obtained from the present transplantation experiments.

Animals↗
PubMed1983

Endotoxin clearance by exchange blood transfusion in septic shock neonates.

The role of exchange transfusion with fresh whole blood in septic shock infants was evaluated. Endotoxin was positive in 8 of 10 infants and completely removed from 6 by exchange transfusion. All 6 infants with negative endotoxins after exchange transfusions survived, but 2 with positive reactions died despite the exchange transfusion. Staphylococcus aureus was cultured in the blood from 2 infants with negative reactions and one of them survived. These findings suggested that the clearance of endotoxin has an important role in exchange transfusion among septic shock neonates.

Endotoxins↗
PubMed1983

Influence of diethylmaleate on the formation of bis(methylmercuric)selenide and methylmercury distribution in rats.

This study was undertaken to examine a possible role of bis(methylmercuric) selenide(BMS) in selenite-induced redistribution of methylmercury in rats. Pretreatment of diethylmaleate(DEM), which depletes tissue reduced glutathione(GSH), completely suppressed the significant increase of BMS produced by selenite injection in the blood of methylmercury-treated rats. Its inhibitory effect was also observed in the kidney and brain. Under the same conditions, the characteristic accumulation in the brain and testis of total mercury induced by selenite was markedly inhibited by DEM pretreatment. Total mercury in these tissues was not altered by DEM alone and BMS in the blood existed in the erythrocytes, but not in the plasma. Thus, it seems likely that the suppressed formation of BMS in the erythrocytes mainly leads to the decreased accumulation of total mercury in the brain and testis.

Animals↗
PubMed1982

Degradation of methylmercury by selenium.

When methylmercury was incubated in the presence of selenite and reduced glutathione (GSH), the mercury which was extracted into benzene under acidic condition decreased gradually with the elapse of time. This decrease was due to the cleavage of mercury-carbon bond of methylmercury. The reaction did not proceed when selenite or GSH was singly added to the reaction mixture. L-Cysteine, 2-mercaptoethanol and sodium sulfide in place of GSH also were effective for decomposition of methylmercury in combination with selenite, but oxidized glutathione (GSSG) and L-cystine were not. This suggests that reduction of selenite is needed for the degradation of methylmercury. Thus, the effect of reduced metabolites of selenite produced by GSH was investigated. Glutathione selenotrisulfide (GSSeSG) required GSH for the degradation of methylmercury, whereas H2Se possessed a strong activity even in the absence of GSH. This may indicate that H2Se is involved directly in the conversion of methylmercury to inorganic mercury. This phenomenon found in in vitro experiments is discussed in relation to the biotransformation of methylmercury.

Animals↗