Biomedical subjects

M Hashimoto

Publications and source records attributed to M Hashimoto.

At least 73 records · Page 4Linked to original sources

PubMed1992

[Effect of halothane on the peripheral cutaneous vasoconstriction and shivering induced by internal body cooling in rabbits].

Although suppression of thermoregulatory mechanisms by anesthetics is generally assumed, the extent to which thermoregulatory responses are active during general anesthesia is not known. To evaluate the effect of anesthetics on thermoregulation, we investigated the threshold body core temperatures to induce peripheral cutaneous vasoconstriction and shivering in spontaneously breathing rabbits. Rabbits are anesthetized with halothane at 0.05, 0.2 and 0.4 MAC (minimum alveolar concentration). Internal whole body cooling was performed by perfusing the cool water through an intestinal U-shaped thermode placed in the colon. Core (esophagus) and peripheral (ear) temperatures were measured with thermistors. The esophageal temperatures at the beginning of peripheral cutaneous vasoconstriction and shivering induced by internal whole body cooling were determined. Peripheral cutaneous vasoconstriction was not significantly affected by halothane. However, the incidence of shivering was significantly decreased by halothane dose-dependently. Threshold of shivering (37.3 +/- 0.8 degrees C) was significantly lower than that of peripheral cutaneous vasoconstriction (38.9 +/- 1.1 degrees C). We conclude that the halothane can exert an influence on shivering.

Animals↗

PubMed1992

[Health effects and personal protection in pest control workers using organophosphorus insecticides].

One hundred and sixteen pest control workers (16 termite control workers (Sprayer I), 46 cockroach or fly-control workers (Sprayer II) and 56 both termite and cockroach or fly-control workers (Sprayer III)) were surveyed by a questionnaire and health examinations. Variety and quantity of pesticide used, personal usage of protective devices (respirator, gloves, work clothes, under wear), and conditions related to bathing were studied by a questionnaire. Relationships between protective devices and blood cholinesterase activity (ChE) were also analyzed. Significant findings were as follows: Most of the pest control operators wore gum gloves and gas masks when involved in termite control. However in the case of cockroach or fly-control, 38% did not wear gloves, and for respiratory protection 44% wore gas masks while 25% of them did not even use any form of respirators. In spite of having better protective practices than sprayers II and III, sprayer I showed significantly lower plasma ChE activity than both sprayer II and III. Plasma ChE activity in sprayers who put on simple respirators tended to be lower than those using gas masks. Plasma ChE activity was also significantly lower in those workers who had less frequent changes of work clothes compared to those with more frequent.

Adult↗

PubMed1992

[Lung injury associated with bucillamine therapy].

We have reported previously a first case of interstitial pneumonitis in rheumatoid arthritis treated with bucillamine in 1989. Thereafter, a dozen cases with lung injury associated with bucillamine therapy have been reported. To explore the similarities among these patients, we tried to carry out a survey concerning the lung injuries in these cases in the present study. We obtained the following results. (1) Patients with lung injury consisted of 7 females and 3 males, aged 65 years on average (59-72). (2) The total amount of bucillamine used was 20-40 g on average (5.1-144 g) during approximately 100 days. (3) Serum rheumatoid factor was positive in 9 of 10 cases. (4) HLA-DR4 was significantly (p less than 0.01) detected in all cases of lung injury associated with bucillamine. (5) Interestingly the effect of bucillamine on rheumatoid disease activity was excellent in most cases. (6) Drug lymphocyte stimulation test (DLST) using bucillamine was performed in 6 cases. Positive DLST was found in 3 of 6 cases. These results suggest that cell-mediated hypersensitivity reaction (Coombs & Gell type IV) may contribute to the development of lung injury associated with bucillamine therapy.

Aged↗

PubMed1992

Comparison of EEG between nasopharyngeal and scalp leads with the aid of an automatic EEG analysis system.

We analyzed the EEG quantitatively with an automatic EEG analysis system, and introduced this system for investigation the relationship between the scalp EEG and nasopharyngeal EEG. The EEG was recorded from healthy volunteers by photic stimulation. We found that components of slow waves like delta and theta were more rich but alpha component was less in the nasopharyngeal EEG than in the scalp EEG. In the analysis of the rate of the appearance of each EEG wave using photic stimulus, a decrease of alpha 1 and an increase of theta 1 are observed in the scalp EEG while there are no specific changes of them in the nasopharyngeal and scalp EEGs. The nasopharyngeal EEG obtained from the vicinity of the base of the brain was thought to originate from the vicinity of the brain stem.

Adult↗

PubMed1992

[A study on work and daily life factors affecting the health of taxi drivers].

In order to elucidate factors affecting taxi drivers health, a questionnaire survey was performed on 5523 taxi drivers and health examinations were conducted on 311 taxi drivers from among them. Analysis by a method of multivariate analysis called Quantification II was performed with dependent variables being blood pressure, the number of subjective symptoms and fatigue on rising, and independent variables being work and daily life conditions. The major results of this survey were as follows: 1) A tendency for hypertension risk to increase with degree of obesity, and both employment as a taxi driver for 1-4 years and over twenty years of taxi driving were positively associated with increase in risk for hypertension. 2) Common factors to all types of work shifts which were related to an increase in the number of subjective symptoms were irregularity of meals, insufficient rest on off days, large number of years engagement at taxi driving, frequent frightening experiences while driving and comparatively short driving distance in one shift. 3) Common factors to all types of work shifts that were connected with fatigue at the time of rising were insufficient rest on off days and long years engagement in taxi driving.

Activities of Daily Living↗

PubMed1992

[A case of anaplastic carcinoma of the mediastinal goiter].

We reported a case of anaplastic carcinoma of mediastinal goiter. The initial symptom was hoarseness, and thyroid scintigram and venogram revealed mediastinal thyroid malignant tumor, although cervical tumor could not be palpated. Operation was performed with median sternotomy. The size of the tumor was 8 x 6 x 3cm. Histological examination showed papillary adenocarcinoma of left lower pole of the thyroid gland which was transformed into anaplastic carcinoma and extended to the mediastinal cavity. Anaplastic carcinoma of mediastinal goiter is very rare, and our case showed anaplastic transformation from papillary adenocarcinoma.

Adenocarcinoma, Papillary↗

PubMed1992

[Modified technique for chronic tricuspid regurgitation in rabbits and evaluation of intestinal malabsorption in the chronic stage of this model].

UNLABELLED: One of pathophysiological processes in cardiac cachexia with severe congestive cardiac failure is malabsorption in the intestine. This malabsorption might be caused by high venous pressure in the intestine, following congestive liver due to congestive cardiac failure. However, this has not been proved experimentally yet. In this experiment, rabbits were utilized because their body weights are relatively equal and their life cycle is shorter than that of dogs, for which experimental procedure has been established. Our purpose was first, to establish the technique which can produce tricuspid regurgitation (TR) in rabbits, and secondly, to examine the degree of malabsorption in these animals in the chronic stage of TR. SURGICAL TECHNIQUE: The TR rabbits (n = 4) were provided by means of division of the chordae of the tricuspid valve through the 4th intercostal space in the right thoracotomy. Division of the chordae was performed through the right atrial incision under direct vision while employing total temporary inflow occlusion. The duration of inflow occlusion varied from one to two minutes. RESULT: The mean of the peak right atrial pressure before the procedure was 6.5 mmHg, that just after the procedure was 16.1 mmHg, and that two to four months after the procedure was 17.0 mmHg. The peak right atrial pressure just after the procedure were higher than those before the procedure, and the peak right atrial pressure two to four months after the procedure were also higher than those before the procedure in all rabbits.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

[Preservation of the heart with University of Wisconsin solution--hemodynamic and morphological evaluation in a canine heterotopically transplanted heart].

University of Wisconsin (UW) solution has been reported to extend the safe cold ischemic time in the preservation of the liver, kidney and pancreas. However, there have been few reports of safe cold ischemic time in heart preservation with UW solution. The purpose of this study was to find whether UW solution can extend the safe cold ischemic time in cardiac transplantation in dogs. Heterotopic cardiac transplantation was performed in mongrel dogs after cold ischemic preservation of the hearts with UW solution, ischemic time 8, 16 and 24 hours (Gr.UW8, Gr.UW16 and Gr.UW24, respectively) and with GIK solution, ischemic time 4 hours (Gr.G4) which is considered the safe cold ischemic time in clinical cardiac transplantation. The following was studied: 1) Emax of the LV, myocardial contraction, by pressure-volume curve with the volume measured conductance catheter method, 2) myocardial tissue blood flow of the LV (MTBF), with laser doppler tissue flow meter, 3) serum CPK and electron microscopical evaluation. Emax and MTBF were measured before transplantation and after reperfusion. Their results were expressed as percentage of the values before transplantation. As results, after 120 minutes from reperfusion, Emax was recovered to 94 +/- 13% in Gr.G4, 104 +/- 11% in Gr.UW8, 67 +/- 22% in Gr.UW16 and 66 +/- 16% in Gr.UW24. Emax in Gr.G4 and Gr.UW8 were significantly (p less than 0.01) higher than that in Gr.UW16 and Gr.UW24. After 120 minutes from reperfusion, MTBF was recovered to 90 +/- 19% in Gr.G4, 98 +/- 9% in Gr.UW8, 63 +/- 19% in Gr.UW16 and 61 +/- 6% in Gr.UW24.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine↗

PubMed1991

Protective effect of WEB 1881 FU on AF64A (ethylcholine aziridinium ion)-induced impairment of hippocampal cholinergic neurons and learning acquisition.

The effect of continuous administration of 4-aminomethyl-1-benzylpyrrolidin-2-one-hemifumarate (WEB 1881 FU) on cerebral cholinergic neurons was studied using rats treated with ethylcholine aziridinium ion (AF64A), a neurotoxic choline analog. AF64A (2.0 nmol, administered i.c.v.) caused a significant decrease in the hippocampal acetylcholine (ACh) content. This decrease in hippocampal ACh content was accompanied by a reduction of choline acetyltransferase (CAT) activity. Under these experimental conditions, the latency of the passive avoidance response of rats, determined with a step-through method, was strongly decreased as compared with that of sham-operated rats. Although treatment with WEB 1881 FU (50 mg/kg per day, administered orally for 7 days) from immediately after the administration of AF64A did not affect the AF64A-induced decrease of ACh in the hippocampus, 100 mg/kg per day of WEB 1881 FU (orally for 7 days) significantly suppressed the AF64A-induced declines in hippocampal ACh content and CAT activity. The AF64A-induced reduction in latency of the passive avoidance response was also significantly antagonized by the treatment with 100 mg/kg per day of WEB 1881 FU (administered orally for 7 days) from immediately after the administration of AF64A. Continuous administration of WEB 1881 FU (100 mg/kg per day, orally for 7 days) from 7 days after the treatment with AF64A also had a significant inhibitory effect on the AF64A-induced decrease in ACh content in the hippocampus. These results suggest that WEB 1881 FU may have protective actions on the destruction of hippocampal cholingergic neurons as well as memory impairment induced by AF64A administration.

Acetylcholine↗

PubMed1991

[Clinical experience of expandable metallic stent placement for malignant biliary obstruction].

Expandable metallic stents of modified Gianturco design were used in nine cases of malignant biliary obstruction. Stents were placed through a percutaneous transhepatic approach without any severe complications. Initial patency was obtained seven of nine patients. Of these seven patients, recurrent jaundice was observed in three within four weeks. One patient had recurrent stenosis after four months due to ingrowth of the tumor. Although the expandable metallic stent offers several theoretical advantages over currently available stents, a disadvantage is that tumors may grow through the spaces between the legs of the wire or grow over the stent. We found that multi-modal treatment combined with radiation therapy was indispensable to maintain the patency of the stent in malignant biliary obstruction.

Aged↗

PubMed1991

Isolation of estrogen receptor-binding sites in human genomic DNA.

Total genomic DNA digested by restriction enzymes was mixed with the DNA-binding domain of the estrogen receptor (ER-DBD) that was expressed in Escherichia coli and the fragments that bound to it were selected by nitrocellulose filter. These fragments were cloned into a plasmid vector and amplified. This selection process was repeated six times and five fragments ranging from 0.2 to 2 kb were isolated. Interestingly, each of these fragments had a perfect palindromic estrogen responsive element (ERE) (GGT-CANNNTGACC). More surprisingly, one of the fragments was found to be derived from the same locus as a fragment obtained by another similar but independent experiment. The results indicate that the ER-DBD region can bind by itself specifically to the perfect palindromic ERE with a 3 base pair spacing but it does not bind strongly enough to the half palindromic EREs or to the imperfect palindromic EREs. Chloramphenicol acetyltransferase assay has shown that some of these fragments have estrogen-dependent enhancer activity, suggesting the existence of a target gene near these fragments. The method described here may be generally applicable for screening and isolation of other transcription factor-binding sites in genomic DNA.

Amino Acid Sequence↗

PubMed1991

Action site of circulating interleukin-1 on the rabbit brain.

Interleukin-1 (IL-1) is now generally accepted as an endogenous pyrogenic mediator of fever induction. IL-1 induces fever by means of activation of arachidonate metabolism in the brain. However, whether circulating IL-1 enters the brain or not, further, the question of where is the action site of circulating IL-1 on the brain, have not been clearly demonstrated. In the present study, to investigate the site of action of circulating IL-1 on the brain, recombinant rabbit interleukin-1 beta (IL-1 beta) was labeled with colloidal gold, injected into the carotid artery of anesthetized rabbits and traced in the brain tissue by means of electron microscopy. Dose-dependent increase in colonic temperature was induced by intravenous injection of used IL-1 in rabbits, while heated IL-1 beta lost the pyrogenicity. Injection of solution of colloidal gold per se did not affect the colonic temperature of afebrile conscious rabbits. However, the IL-1/gold conjugates induced fever; IL-1 beta retained its pyrogenic potency even after labeling with gold. By electron microscopy, the IL-1/gold conjugates were observed on the surface and in the vesicle of endothelial cells of the capillary in the region of the anteroventral third ventricle. This implies that circulating IL-1 acts, as the initial step to induce fever, on the endothelium in that region.

Animals↗

PubMed1991

Expression of mRNA for activin-binding protein (follistatin) during early embryonic development of Xenopus laevis.

Follistatin is a specific activin-binding protein and is supposed to control activin functions. During Xenopus embryonic development, activin is thought to act as a natural mesoderm-inducing factor. We isolated here the Xenopus follistatin cDNA from Xenopus ovary cDNA library and studied the expression of Xenopus follistatin gene during the course of early embryonic development. The Xenopus follistatin has an 84% homology at the level of deduced amino acid sequence with human and porcine follistatin. Its 3.5 kb mRNA is first expressed at the gastrula stage, when the expression of activin mRNA becomes first detectable, and increased thereafter. Another species of 2 kb mRNA become detectable from early neurula and also increased dramatically in tadpole. These results suggest that the follistatin acts also as a regulator of activin in inductive interactions during amphibian embryonic development.

Amino Acid Sequence↗

PubMed1991

Characterization and mechanism of fever induction by interleukin-1 beta.

To investigate the relation of arachidonate metabolism to the induction of fever by interleukin-1, indomethacin was administered in either an intracerebroventricular (icv) or a subcutaneous (sc) route in conscious rabbits. Fever induced by icv administration of recombinant human interleukin-1 beta (rhIL-1 beta) was depressed by either icv or sc pretreatment with indomethacin. Fever induced by intravenous (iv) administration of rhIL-1 beta was significantly inhibited, though initial small increase in colonic temperature still remained, and was completely depressed by combination of icv and sc pretreatment with indomethacin. Intracerebroventricularly administered recombinant rabbit IL-1 beta (rrIL-1 beta) induced dose-dependent increases in colonic temperature, which was depressed by sc pretreatment with indomethacin. There is little species specificity between human and rabbit IL-1 beta, in terms of the pyrogenic potency and the inhibitory effect of sc indomethacin on fever induced by icv IL-1 beta. Further, fever caused by icv administration of sodium arachidonate was significantly depressed by sc pretreatment with indomethacin. These results show that the inhibitory effect of indomethacin, administered either icv or sc, on IL-1 beta-induced fever is similar to that of IL-1 alpha-induced fever reported previously. This suggests that the site of arachidonate metabolism significantly involved in the mechanism of fever induction by IL-1 is easily accessible to the brain from the blood.

Animals↗

PubMed1991

PAF inhibitory activity of diketopiperazines: structure-activity relationships.

FR900452, a natural product isolated from the culture broth of Streptomyces phaeofaciens No. 7739, was found to inhibit PAF-induced rabbit platelet aggregation with an IC50 of 3.7 x 10(-7)M. FR900452, 1-methyl-3-[1-[5- methylthiomethyl-6-oxo-3-(2-oxo-3-cyclopenten-1-yli- dene)-2-piperazinyl]ethyl]-2-indoline, has an oxocylopentylidene group incorporated as a vinylogous amide in a diketopiperazine skeleton. This unique structure led us to synthesize diketopiperazine derivatives, 3-arylalkyl- 6-substituted-piperazine-2,5-diones. Their observed PAF inhibitory activity suggest that the D-D configuration of diketopiperazine is an important factor for anti-PAF activity and that the hydrophobic aromatic portion may play a specific role in the binding of the diketopiperazine to the PAF receptor.

Animals↗

PubMed1991

Lymphocytic adenohypophysitis: an immunohistochemical study.

Lymphocytic adenohypophysitis is a rare inflammatory disorder of the anterior pituitary gland. In some cases, there is evidence of concurrent autoimmune disease. We present the case of a 39-year-old woman who developed visual disturbance during the early postpartum period. Magnetic resonance imaging revealed an intrasellar mass with suprasellar extension. Study of the tumor tissue showed diffuse infiltration of the entire pituitary gland by lymphocytes and plasma cells. Immunohistochemical examination revealed that the majority of the infiltrating lymphocytes were T cells that might have modulated the immunoreaction to the anterior pituitary gland. We suggest that the disorder is related to cell-mediated immunity as well as humoral immunity.

Adult↗

PubMed1991

Age-related increase in the uptake of acetylated low density lipoprotein into cultured endothelial cells from rat aorta.

A simple and reliable method for the separation of endothelial cells from the thoracic aorta of rats was established in the present study. The cultured endothelial cells separated by this improved explantation method showed typical characteristics of endothelial cells, morphology of cobblestone monolayer, immunoreactivity against antibodies to Von Willebrand's factor and angiotensin I converting enzyme, and the ability to uptake acetylated low density lipoprotein (LDL) labeled with 1,1'-dioctadecyl-1-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate (DiI-Ac-LDL). The purity of the cultured endothelial cells separated by this method was over 98%, and the cells were maintained in culture for 3-4 months. Age-related changes of the uptake of DiI-Ac-LDL into the endothelial cells were then estimated by using the cultured endothelial cells separated from the aortas of young (4-8 weeks old) and old (95-100 weeks old) rats. When fluorescent DiI-Ac-LDL-labeled endothelial cells were sorted and analyzed by a cell sorter, the fluorescence intensity of the cultured cells from old rats was stronger than that of the cells from young rats. Therefore, the present results show that the uptake of the acetylated LDL into the endothelial cells increases with rat aging, and suggest the age-related increase in the acetyl LDL receptor in the endothelial cells of the rat aorta.

Acetylation↗

PubMed1991

Cross-adaptive response in Escherichia coli caused by pretreatment with H2O2 against formaldehyde and other aldehyde compounds.

A cross-adaptive response (CAR), defined as a reduction of the effects of an agent by pretreatment with another agent, was demonstrated when E. coli WP2 cells were pretreated with hydrogen peroxide (H2O2) followed by challenging treatment with aldehyde compounds. Pretreatment with a sublethal dose (60 microM) of H2O2 for 30 min made WP2 cells resistant to the killing effects of formaldehyde (FA), and 4 other mutagenic aldehydes: glutaraldehyde, glyoxal, methyl glyoxal and chloroacetaldehyde. CAR was also observed in WP2uvrA (uvrA-) and ZA12 (umuC-) cells, but not in ZA60 (recA-) and CM561 (lexA- (Ind-] cells. A role of recA and lexA in CAR was further suggested by the lack of beta-galactosidase induction in recA- and lexA- cells by H2O2. CAR and beta-galactosidase induction, however, were found to be separate events since CAR was recovered by introducing the recA+ gene into lexA- cells, but no induction of beta-galactosidase by H2O2 was observed in cells with the same gene transfer. These results suggest that H2O2 has the capacity to induce a function which reduces the killing effects of aldehydes, and the function is controlled by the recA gene without involvement of SOS response.

Acclimatization↗