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Biomedical subjects

C Shimada

Publications and source records attributed to C Shimada.

At least 19 recordsLinked to original sources
PubMed2001

Induction of anesthesia with ketamine reduces the magnitude of redistribution hypothermia.

UNLABELLED: Hypothermia after induction of general anesthesia results largely from core-to-peripheral redistribution of body heat. Both central inhibition of tonic thermoregulatory vasoconstriction in arteriovenous shunts and anesthetic-induced arteriolar and venous dilation contribute to this redistribution. Ketamine, unique among anesthetics, increases peripheral arteriolar resistance; in contrast, propofol causes profound venodilation that other anesthetics do not. We therefore tested the hypothesis that induction of anesthesia with ketamine causes less core hypothermia than induction with propofol. Twenty patients undergoing elective surgery were randomly assigned to anesthetic induction with either 1.5 mg/kg ketamine (n = 10) or 2.5 mg/kg propofol (n = 10). Anesthesia in both groups was subsequently maintained with sevoflurane and 60% nitrous oxide in oxygen. Forearm minus finger, skin-temperature gradients <0 degrees C were considered indicative of significant arteriovenous shunt vasodilation. Ketamine did not cause vasodilation just after induction, whereas propofol rapidly induced vasodilation. Core temperatures in the patients given ketamine remained significantly greater than those in the patients induced with propofol. These data suggest that maintaining vasoconstriction during induction of anesthesia reduces the magnitude of redistribution hypothermia. IMPLICATIONS: Core hypothermia during the first hour of anesthesia was less after induction of anesthesia with ketamine than propofol. Maintaining arteriovenous shunt vasoconstriction during induction of anesthesia reduces the magnitude of redistribution hypothermia.

Adult↗
PubMed2001

[Care networks of visiting nurse agencies before the long-term care insurance act].

PURPOSE: To describe how organizational background impacts on care networks of visiting nurse agencies. METHODS: A questionnaire was sent to all visiting nurse agencies (3,178) in Japan, and 1,548 responded. Questions were asked about the agency's background, management system, and cooperation with other community care agencies. FINDINGS: Seventy-nine percent of visiting nurse agencies were affiliated to medical organizations consisting of hospitals, clinics, or medical nursing facilities, The exceptions cooperated with various types of community service agencies, including home care agencies, assisted device agencies, housing improvement agencies, or volunteer services. The visiting nurse agencies had more frequent contact with housing improvement agencies when home care aid agencies were included within the same organizations. The results suggest that visiting nurse agencies can be divided into two types with reference to the long-term care insurance system. One has strong cooperative relationships with hospitals, and the other with community care agencies.

Community Health Nursing↗
PubMed2000

[Social interaction and mortality in a five year longitudinal study of the elderly].

This study clarified the relationship between social interaction and mortality using a five year longitudinal study. The subjects were all 60 years or above who lived in a farming community near major urban centers in Japan (n = 1,069). A total of 153 subjects died within the five year period after the baseline survey. A questionnaire was utilized, the contents of which were about social interaction (using the "Index of Social Interaction" which consisted from 5 subscales: Independence, Social curiosity, Interaction, Feeling of Safety, and Participation in the society), health status, life style, and subjects' feeling about themselves. The results were as follows: 1) low score on "Index of Social Interaction" was significantly related to five-year mortality, 2) the mean score of "index of Social Interaction" of deceased was significantly lower then survived subjects aged 75 and over, 3) logistic regression analysis adjusted for age, sex, length of education, and health status revealed that odds of mortality were significantly high with lower score in the Index of Social Interaction.

Aged↗
PubMed1999

[A study on the concentration of eosinophil cationic protein in chronic sinusitis].

The relationship between eosinophil and chronic sinusitis was investigated by measuring the concentration of eosinophil cationic protein (ECP). In addition to the blood, a cytological brush was inserted into middle meatus to scrape the nasal membrane, and the concentration of ECP in the collected specimen was measured. There was a moderate degree of correlation between the blood eosinophil count and the ECP concentration in the blood (r = 0.543, p < 0.01). On the other hand, there was high degree of correlation between the number of EG2-positive cells and ECP of the nasal membrane in the middle meatus (r = 0.805, p < 0.001), reflecting the amount of ECP in the nasal mucous membrane. The ECP in 10 control group subjects and 14 patients with severe chronic sinusitis and nasal polyps was significantly lower than that in 14 patients with severe chronic sinusitis and asthma (p < 0.01). The ECP concentration of the nasal membrane in the middle meatus was significantly lower in patients showing a good postoperative course compared with patients showing a poor postoperative course following Endoscopic Sinus Surgery (p < 0.01). These findings suggest that eosinophils are closely related to the pathology and clinical course of chronic sinusitis, and that the ECP concentration of the nasal membrane in the middle meatus reflects the pathology of chronic sinusitis. The ECP concentration thus has potential as a prognostic indicator for chronic sinusitis.

Adult↗
PubMed1998

Determination of 7alpha-hydroxycholesterol in dog plasma by high-performance liquid chromatography with fluorescence detection.

A new method was developed for the determination of 7alpha-hydroxycholesterol (7-HC) in dog plasma by means of high-performance liquid chromatography (HPLC) with fluorescence detection. 7-HC extracted with organic solvent from plasma was purified with Bond Elut 2OH and converted to a sensitive fluorescent derivative containing double coumarin groups at the C-3 and C-7 positions of the steroid nucleus with 7-methoxycoumarin-3-carbonyl azide. After removal of the excess reagent with Bond Elut NH2, the 7-HC derivative was separated by reverse-phase HPLC method. The detection limit of the authentic 7-HC-3,7-coumarin derivative was 4 pg (S/N = 5), approximately four times less than that of the 7-HC-3-anthroyl derivative yielded by reaction of 7-HC with 1-anthroylcyanide. The newly developed method was used to investigate the effects of consecutive oral administrations of cholestyramine (CA) on 7-HC levels in dog plasma. The plasma 7-HC levels of the CA-treated group were two times greater than those of the control group.

Animals↗
PubMed1997

[Evaluation of environmental stimulation for 18 months and the related factors].

With the disinteglation of social ties in the community, the role of environmental stimulation as an important function in children's health has been recognized and social services to evaluate the environmental stimulation are important. The Evaluation of Environmental Stimulation (EES) is a questionnaire which directly evaluates the interaction between the child and caregiver, and its effectiveness as a support system. The purpose of this study is to clarify characteristics of the EES by using statistical analysis. The subjects were 388 children of about 18 months who came for the compulsory health examinations. Caregivers were asked to answer the questionnaire. The results are as follows; 1) Children at risk for physical, mental and social development scored low for the 'social stimulation' subscale and in total score. 2) Children at the risk of medical and social diagnosis got fewer points in 'independence' subscale, 'physical stimulation' subscale, and total score than children without risk. 3) By ANOVA statistics, risk for development and risk for medical and social diagnosis had interactions according to child's sex. These results show that EES is effective in finding the risk of environment for children and for development of prevention measures, and appears to be useful as a screening system for health social services.

Age Factors↗
PubMed1994

[Effects of inverse ratio ventilation and positive end-expiratory pressure on gas exchanges in dogs with oleic acid induced pulmonary edema].

The purpose of this study was to determine the effect of inverse ratio ventilation (IRV) on gas exchanges and circulatory systems in 56 mongrel dogs with oleic acid induced pulmonary edema. The dogs were divided into 9 groups and were ventilated with 9 kinds of ventilatory modes such as I:E ratio of 1:2 (control), 2:1 (2:1 IRV), 3:1 (3:1 IRV), 1:2 with 5 cmH2O PEEP (1:2 PEEP 5), 2:1 with 5 cmH2O PEEP (2:1 PEEP 5), 3:1 with 5 cmH2O PEEP (3:1 PEEP 5), 1:2 with 10 cmH2O PEEP (1:2 PEEP 10), 2:1 with 10 cmH2O PEEP (2:1 PEEP 10) and 3:1 with 10 cmH2O PEEP (3:1 PEEP 10), using a Servo ventilator 900C. IRV could not improve arterial oxygenation in dogs with oleic acid induced pulmonary edema, but PEEP could significantly improve arterial oxygenation depending on PEEP level. Although in the control group, PaCO2 increased gradually, PaCO2 was kept constant for 8 hours in the 3:1 IRV groups. In the 2:1 group, PaCO2 did not change significantly until 6 hours, but in IRV with 10 cmH2O PEEP groups, PaCO2 showed the highest increase. There was no significant alteration in hemodynamics after ventilatory modes were changed to IRV. Although oxygen delivery was the best in the 3:1 IRV group, there was no statistical significance between the 3:1 IRV group and others. It was concluded that IRV did not improve arterial oxygenation but showed a favorable effect for CO2 elimination, in dogs with oleic acid induced pulmonary edema.

Animals↗
PubMed1993

[Effects of the volume of the reservoir bag and the amount of fresh gas flow on FRC during CPAP].

We have examined effects of the volume of the reservoir bag and the amount of fresh gas flow (FGF) on FRC during CPAP with PEEP level of 8 or 11 cmH2O. We used reservoir bags of 4 different volumes (5, 10, 15, 20l). We set up the air way pressure graduation between inspiration and expiration (delta P) by adjusting FGF rate, then we measured delta FRC and other respiratory parameters in 8 volunteers (26.3 +/- 0.8 yo). With the same PEEP level, delta P decreased but FRC increased by increasing FGF rate. When we used a lager reservoir bag, FGF rates which are necessary to set up the minimum delta P decreased during CPAP. We could obtain a larger delta FRC by using a larger reservoir bag compare with a smaller one, at the same delta P using same CPAP level. We should consider not only delta P but also the volume of the reservoir bag to obtain a reasonable and comfortable CPAP.

Adult↗
PubMed1992

Beneficial effect of intravenous taurine infusion on electroretinographic disorder in taurine deficient rats.

We investigated the effect of intravenous taurine infusion on the electroretinogram (ERG) of taurine-deficient rats produced by treatment with guanidinoethyl sulfonate (GES), a taurine transport inhibitor. Mother rats were fed a taurine-free diet and given drinking water containing 1% GES from 2 weeks of gestation to weaning. The same feeding conditions were applied to male offspring after weaning. Both ERG measurement and continuous infusion of taurine at a dose of 10, 30 or 100 mg/animal/day were performed for 3 weeks from 7 to 10 weeks of age. GES-treatment reduced a- and b-wave amplitudes to 50% of the control levels and also increased b-wave latencies. Intravenous infusion of taurine improved these ERG abnormalities in a dose-dependent manner. Taurine concentrations in plasma, eyes and brain were also decreased by treatment with GES, and dose-dependent recovery was observed after infusion with taurine, although the concentrations of other amino acids were not affected by GES-treatment and infusion of taurine. Observations of morphological changes revealed that the retinal damage in GES-treated animals was decreased by taurine infusion. These results indicate that the changes in ERG and retinal structure observed in taurine deficiency are improved by intravenous infusion of taurine.

Amino Acids↗
PubMed1991

Peripheral vascular permeability following a thermal injury to the airway.

Effects of thermal injury to the airway on the vascular permeability in the region of head and neck, were studied in the canine models. The thermal airway injury was produced by an inhalation of a gas burner's flame through the metallic tracheostomy cannula. The changes in vascular permeability were evaluated by calculating the reflection coefficient, which was obtained by the protein washdown technique into lymph. The reflection coefficient after the flame inhalation did not show any increases, while it increased significantly after a histamine infusion into the carotic artery. We concluded, that the vascular permeability in the unburned area does not increase at least in the first 3 hr after a thermal injury to the airway.

Journal Article↗
PubMed1991

[Drug-induced seizures in taurine-deficient mice].

Appearances of pentetrazole-, picrotoxin- and strychnine-induced convulsive seizures in taurine-deficient mice produced by treatment with guanidinoethyl sulfonate (GES), a taurine transport antagonist, were investigated. Mice were fed a taurine-free diet and water containing 1% GES from 2 weeks of pregnancy to weaning. The same feeding condition was applied to male offsprings from 3 weeks of age. At 5 weeks of age, convulsants were administered to some mice and the others were sacrificed for determination of brain amino acids concentrations. The incidences of both seizure and death for strychnine and death for picrotoxin were enhanced by treatment with GES, whereas the latency of pentetrazole-induced tonic extensor was prolonged. Significant decrease of brain taurine, asparaginic acid and GABA concentrations were observed in mice treated with GES. These results suggest that convulsive seizures caused by disinhibition of taurine and GABA system are enhanced by deficiency of brain taurine level.

Amino Acids↗
PubMed1990

The effect of neonatal exposure to chronic footshock on pain-responsiveness and sensitivity to morphine after maturation in the rat.

Rat pups in 3 groups respectively were given daily footshock, exposure to a footshock apparatus without shock, or no handling from birth to 21 days of age and reared with no manipulation afterwards. After maturation (90-100 days of age), they were assessed for hot-plate paw-lick latency, morphine-induced analgesia and opiate receptor binding assay. In footshocked animals, a significant increase was found in paw-lick latency and in antinociceptive effects of morphine (1.25, 2.5, and 5.0 mg/kg) in comparison with two control groups. The antinociceptive effect of morphine in all 3 groups was antagonized by pretreatment with naloxone (2.0 mg/kg). No significant difference was found in binding activities (Bmax and Kd) for both [3H]naloxone and [3H]Dala2, D-Leu5-enkephalin between the 3 groups. These results suggest that exposure to footshock stress in the preweanling period has a long-term effect on the sensitivity of rats to painful events, probably due to chronic functional changes in endogenous opiate systems at presynaptic level rather than in postsynaptic opiate receptor binding activity.

Aging↗
PubMed1990

[The effect of CO2 absorbent shape on its functioning time].

A comparative investigation into the functioning time of three brands of CO2 absorbents was performed. The three investigated brands were: Viosorb, Wakolime, and Wakolime-A. In this study PICO2 was measured to know the drug's functioning time and CO2 elimination from the model lung fixed at 200 or 300 ml.min-1. PICO2 was less than 1 mmHg for 34 to 55 hours at VCO2 of 200 ml. min-1 and for 32 to 48 hours at VCO2 of 300 ml.min-1. PICO2 increased exponentially in all CO2 absorbents. There were statistically significant relation between PICO2 and time. The CO2 absorbent whose shape is tablet has the longest functioning time because it could be placed smoothly in the canister. It is concluded that the shape of CO2 absorbent plays a role in determining its functioning time.

Absorption↗
PubMed1979

Effect of hippocampus extirpation in the rat on glutamate levels in target structures of hippocampal efferents.

Twenty days after complete uni- or bilateral hippocampus extirpation in rats, a 25% decrease in glutamate concentration was observed in the septum. Glutamate content also decreased in other terminal structures of the hippocampo-subicular system, i.e. entorhinal cortex, nucleus accumbens septi, mammillary bodies and contralateral hippocampus. It is concluded that the fall in glutamate content which is absent in caudate nucleus is specific for target regions of the hippocampal efferents, adding further support to the suggested transmitter role of glutamate in the limbic system.

Animals↗
PubMed1979

High concentration of gamma-aminobutyric acid in pancreatic beta cells.

The gamma-aminobutyric acid (GABA) concentration of pancreatic islets in rats treated with streptozotocin (STZ) and of human insulinoma tissue was studied. Seven hours after the administration of 65 mg/kg body weight of STZ, a distinct increase in serum insulin concentration and at the same time a decrease in blood glucose level were seen. Twenty-four hours after the injection of STZ, however, the level of serum insulin decreased much, whereas that of blood glucose increased considerably. On the other hand, the GABA concentration of the islet was reduced dramatically to about one-tenth the control level after both 7 and 24 h. The histologic investigations of the islets revealed the destruction of B cells but no changes in A and D cells 7 and 24 h after the treatment of STZ. Nerve fibers and nerve endings in the islets were preserved intact all through the study. The GABA and insulin contents of the two cases of human insulinoma were determined. One insulinoma, which was compactly occupied with B cells according to its histologic features, contained a high concentration of GABA. The other tumor, having a rather sparse distribution of B cells in it as compared with the former case, possessed a lower concentration of GABA, but it was still high compared with that of its surrounding tissues. The present observations indicate that a large amount of GABA is available in the B cells of the pancreatic islets.

Adenoma, Islet Cell↗
PubMed1977

GABA in pancreatic islets.

A high concentration of gamma-aminobutyric acid (GABA) and a high activity of glutamate decarboxylase (GAD), enzyme for GABA synthesis, were demonstrated in the rat pancreatic islets using a recently developed assay method combining the GABase system with the enzymatic NADP-NADPH cyclin method. Both GABA concentration and GAD activity in the pancreatic islets were comparable to those in the central nervous system (CNS). An insulinoma consisting mainly of B cells possessed a high concentration of GABA and a high activity of GAD. On the other hand, in the pancreatic islets of rats after treatment with streptozotocin, a specific attacker of B cells, GABA was negligible in amount. The occurrence of GABA in the pancreatic islets, at least B cells, apparently supports the view of Fujita that the islet cells are paraneurons. Presence of exogenous GABA does not influence the glucose- and amino acid-induced insulin release. The uptake of 3H-GABA into the pancreatic islet was small in amount as compared with that into the brain tissue such as the substantia nigra. These observations suggest that the different compartmentation of GABA in the islets from that in the CNS.

Adenoma, Islet Cell↗