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Biomedical subjects

K Shimoji

Publications and source records attributed to K Shimoji.

At least 127 records · Page 7Linked to original sources
PubMed1992

[Digital imaging microscopy for intracellular Ca2+ in cultured single rat vascular smooth muscle cells using fluorescent Ca2+ indicator "fura-2"].

We presented the principle and methodology of digital imaging microscopy for intracellular Ca2+ in cultured single vascular smooth muscle cells of the rat using fluorescent Ca2+ indicator "fura-2". The methods seemed useful for studying the physiological and pathological phenomena in a single smooth muscle cell. Analysis of the spatial and temporal dynamics of intracellular Ca2+ might be crucial for studying the active sites of vasoactive or anesthetic drugs in a vascular smooth muscle cell as well as for understanding pathophysiology of the arterial spasm.

Animals↗
PubMed1991

High sensitivity of porcine cerebral arteries to endothelin.

The threshold concentration of endothelin to induce contractions in porcine cerebral arteries (anterior cerebral, Willis ring and basilar artery) was lower than those for coronary and renal arteries. The median effective concentrations (ED50) of endothelin in cerebral arteries were also significantly lower than those for coronary and renal arteries. There was no significant difference in the sensitivity to endothelin among cerebral arteries, or between coronary and renal arteries. The maximal percentage of contractions induced by endothelin, as compared to that induced by 10(-1) M potassium chloride, was not significantly different between the arteries.

Animals↗
PubMed1991

Observation of spinal canal and cisternae with the newly developed small-diameter, flexible fiberscopes.

Small-diameter (0.5-, 0.9-, and 1.4-mm) flexible fiberscopes were developed for visual diagnosis of spinal canal diseases. The fiberscopes were introduced via a Tuohy needle into the subarachnoid and epidural spaces of ten patients with various pain syndromes. Clear visualization of the subarachnoid space was achieved using the fiberscopes. The epidural space could be visualized only during withdrawal of the fiberscope. In five cases, the fiberscope could be advanced up to the level of the cisternae without causing the patient any discomfort. A slight headache and transient fever were noted after the examination in five and two cases, respectively, but no other complications occurred. Interestingly, preexisting pain diminished (two cases) or disappeared (one case) after the myeloscopy in three of five cases in which the myeloscopy revealed aseptic adhesive arachnoiditis. Further studies should be carried out to evaluate the usefulness of this technique.

Adult↗
PubMed1991

[Severe dyspnea caused by vecuronium bromide administration for priming and precurarization].

Vecuronium bromide 1mg was injected intravenously for priming or precurarization in 42 cases. Apparent dyspnea was observed in 2 cases. The doses of vecuronium bromide in these 2 cases, 0.018 and 0.016 mg.kg-1, respectively were the same and less than those in the other 40 cases (0.018 +/- 0.003 mg.kg-1, mean +/- SD). Although respiratory sparing effect of vecuronium bromide is expected, intensive respiratory assist should be taken at the time of priming or precurarization with the drug.

Aged↗
PubMed1991

[Anesthetic management of pheochromocytoma by continuous intravenous injection of prostaglandin E1].

We had five cases of surgical removal of pheochromocytoma by continuous intravenous injection of prostaglandin E1. During anesthesia, we used Swan-Ganz catheter for circulatory monitoring and measured plasma catecholamines. When PGE1 dose was increased from 0.05 to 0.1 and 0.15 microgram.kg-1.min-1, total systemic vascular resistance and mean arterial pressure were decreased but heart rate and cardiac output were not significantly altered from the preanesthetic values. Plasma catecholamines were also similar to the preanesthetic values. Therefore, the results suggest that the mechanism of suppression of hypertension by PGE1 is by affecting vascular beds directly rather than by diminishing catecholamine excretion from sympathetic nerve and adrenal medulla. During manipulation of pheochromocytoma, mean arterial blood pressure increased extremely. Although PGE1 was injected at a rate of 0.3 to 0.5 microgram.kg-1.min-1 in some cases, we could not suppress the elevation of blood pressure. PGE1 alone could not normalize blood pressure and heart rate, and other cardiovascular agents were necessary.

Adolescent↗
PubMed1991

[Adoptive immunotherapy for pulmonary tuberculosis caused by multi-resistant bacteria using autologous peripheral blood leucocytes sensitized with killed Mycobacterium tuberculosis bacteria].

A patient with pulmonary tuberculosis caused by bacteria resistant to various anti-microbial agents was treated with adoptively transferred autologous peripheral blood leucocytes (PBL) sensitized with killed Mycobacterium tuberculosis organisms in vitro. The 32-year-old man was admitted to our hospital from National Sanitarium Okinawa Hospital with weight loss, high fever, and rapid aggravation on chest X-ray. Patient's PBL obtained by leukapheresis and separated with Ficoll-Hypaque solution were cultured with killed Mycobacterium tuberculosis bacteria of 0.4 microgram per ml at 1 x 10(6) cells per ml for 7 days in media containing 0.5 U recombinant 1L-2 per ml. After incubation, PBL were layered and centrifuged on Ficoll-Hypaque solution and washed three times with saline. PBL (1-3 x 10(8)) were combined and concentrated for infusion in 20 to 30 ml saline. After injection, patient displayed fever and transitory drop of PaO2. Although the patient did not have an improved on chest X-ray, his fever was alleviated, weight was increased, accelerated ESR was slightly improved, and the number of organisms in sputum (Number of Gaffky) temporarily decreased. Adoptive immunotherapy using the autologous PBL which were sensitized with killed bacteria may be an effective anti-tuberculous immunotherapy.

Adult↗
PubMed1990

Effects of isoflurane on spinal inhibitory potentials.

The effects of isoflurane on segmental spinal cord potentials and heterosegmental slow positive potentials in response to fore- and hindpaw stimulation were studied in the rat. The heterosegmental slow positive potential and late (second) component of the slow positive wave (P2) of segmental spinal cord potential, thought to be primary afferent depolarization, an agent of presynaptic inhibition activated by a feedback loop via supraspinal structures, were greatly suppressed by the anesthetic. In contrast the negative wave (N1) of segmental spinal cord potential, believed to be synchronized activity of dorsal horn neurons, was only minimally affected. No differential effects of isoflurane on spinal cord potentials activated by fore- and hindpaws were found. Thus, the inhibitory activities of the spinal cord, particularly those produced by a feedback loop via supraspinal structures, are suggested to be highly vulnerable to isoflurane.

Animals↗
PubMed1990

Effects of thiopental, pentobarbital, and ketamine on endothelin-induced constriction of porcine cerebral arteries.

Contractile mechanisms of endothelin, a newly isolated vasoactive substance from endothelium, were evaluated in anterior cerebral arteries (ACA). Furthermore, the effects of thiopental, pentobarbital, ketamine, and diltiazem on the endothelin-induced cerebral vasoconstriction were also studied. Endothelin induced cerebral arterial contractions in concentrations above 3 X 10(-10) M. The median effective concentration (ED50: X10(-9) M) of endothelin was 2.1 +/- 0.7 (n = 6). Endothelin did not elicit contractions in preparations soaked in Ca2(+)-free solution, but addition of 2.5 mM Ca2+ to the baths induced marked contractions. Thiopental and pentobarbital attenuated endothelin-induced contractions at concentrations above 3 X 10(4) M, while ketamine was effective above 10(-3) M. In contrast, diltiazem decreased endothelin-induced vasoconstriction at 10(-6) M. The findings suggest that endothelin may cause contractions of porcine cerebral arteries by influx of Ca2+ through Ca2+ channels. The cerebral vasomotion induced by endothelin, however, does not seem to be influenced by clinical doses of barbiturates and ketamine.

Animals↗
PubMed1990

[A case of Pneumocystis carinii pneumonia with hyperinfection of Strongyloides stercoralis complicated with smoldering adult T-cell leukemia].

A 43-year-old woman visited a clinic for an attack of bronchial asthma which she had been suffering since her childhood. She was treated with prednisolone which was used for the first time. Two weeks later, she had a fever and her chest X-ray showed diffuse reticulonodular shadows on both middle to lower lung fields. In spite of the use of antibacterial drugs, her symptoms such as cough, dyspnea, malaise and fever increased. It was revealed that she had Stronglyoides sterocoralis in the stool. She was referred to our department for treatment and further examination. Transbronchial lung biopsy (TBLB) was performed, and cyst of Pneumocystis carinii were histologically detected in the lung specimen. Anti-human T-lymphotropic virus type 1 (HTLV-1) antibody in the serum was 1:4,096 less than. Typical adult T-cell leukemia (ATL) cells were also observed in the peripheral blood smear at the rate of 10-15% of leukocytes. The parasite was observed in the sputum too. We diagnosed her as having Pneumocystis carinii pneumonia with hyperinfection of Strongyloides stercoralis complicated with smoldering ATL, and the pneumonia might have been induced by steroid therapy (total doses of 500 mg, for 25 days). After sulfamethoxazole-trimethoprim (ST compound) was used for the Pneumocystis carinii pneumonia, her symptoms markedly subsided, and the chest X-ray findings turned to normal by 45 days after the treatment. Thiabendazole was initially administered for the Strongyloidiasis and the parasite temporarily disappeared from both sputum and stool. Then pyrvinium pamoate and mebendazole were used, but the parasite could not be completely eradicated in the stool. We did not treat the smoldering ATL because there were no symptoms. We have been looking after her as an outpatient now, and she has neither symptoms nor signs.

Adult↗
PubMed1990

Endothelial modulation of norepinephrine-induced constriction of rat aorta at normal and high CO2 tensions.

Endothelial modulation of norepinephrine (NE)-induced constriction of the isolated rat aorta was studied at normal (PCO2, 41 +/- 0 mmHg) and high CO2 tensions (PCO2, 91 +/- 1 mmHg). In preparations with intact endothelium, increased CO2 tension resulted in rightward shift of the NE dose-response curve with attenuation of maximal contraction. This effect of CO2 was not modified by indomethacin. Treatment with hemoglobin or rubbing of the endothelium meant that increased CO2 tension still resulted in rightward shift of the NE dose-response curve but without altering the maximal contractile response. The basal guanosine 3',5'-cyclic monophosphate (cGMP) levels in control and NE-treated aortic preparations were not affected by increasing the CO2 tension. Thus the inhibitory action of CO2 on NE-induced contraction in the presence of endothelium may not be derived from facilitation of endothelium-derived relaxation factor (EDRF)-induced cGMP synthesis. Increasing the CO2 tension attenuated the sustained contraction induced by the addition of NE and Ca2+ (2.5 mM) to intact endothelium preparations previously bathed in Ca2(+)-free solution. Further addition of Ca2+ (total 5.0 mM) did not increase the contraction. These findings suggest that the intrinsic activity of NE is greatly modified by endothelium at a high CO2 tension. Vasodilation during hypercapnia may be induced at least in part by synergistic actions of EDRF and CO2 on smooth muscle cells.

Animals↗
PubMed1990

[Anesthesia for pectus excavatum].

The incidence of arrhythmia, postoperative complication and pulmonary oxygenation (PaO2) were studied in 48 patients with pectus excavatum scheduled for the Ravitch operation under halothane-nitrous oxide-oxygen (GOF) and enflurane-nitrous oxide-oxygen (GOE) anesthesia. Preoperative abnormalities of ECG were observed in 36 of 18 cases. Main abnormalities were incomplete right bundle branch block, left atrium enlargement, and sinus arrhythmia. Ventricular arrhythmia was observed in 4 of 12 cases during GOF anesthesia, whereas no arrhythmia was observed during GOE anesthesia. In postoperative chest X-ray, pulmonary atelectasis (60%), pleural effusion (48%), and pneumothorax (8%) were observed. The results suggest that GOE is more advantageous for pectus excavatum operation than GOF. Postoperative pulmonary surveillance is important for pectus excavatum operation.

Adolescent↗
PubMed1990

[A case of bronchiolitis obliterans organizing pneumonia in a patient with rheumatoid arthritis].

A 54-year-old man with rheumatoid arthritis visited his general practitioner because of fever and cough. Chest X-ray showed an infiltrative shadow in the right lower field. Antibiotic treatment was not effective, and the specimens obtained by transbronchial lung biopsy was not diagnostic. The patient was transferred to our hospital for further examination and treatment. Previously he had been treated with prednisolone in the knee joint for rheumatoid arthritis. Open lung biopsy was performed. The specimen obtained showed bronchiolitis obliterans organizing pneumonia (BOOP) histologically. The patient recuperated and the chest X-ray shadow decreased with no therapy except the previous treatment with prednisolone.

Arthritis, Rheumatoid↗
PubMed1990

[The effect of DREZ (dorsal root entry zone) lesions on intractable pain in patients with spinal cord injury].

Some patients with spinal cord injury complain of a severe intractable pain. This intractable pain places new hurdles on the road to return to the ordinary daily life in these patients. The effective therapy for the intractable pain has not been established. Dorsal root entry zone (DREZ) lesion was originally reported by Nashold et al to alleviate deafferented pain syndrome. Three male and one female patients with intractable pain following spinal cord injury were treated with DREZ-lesions. One month after operation, all 4 patients obtained good pain relief. However, at a follow-up period till February 1989 (ranging 11 months from 2 years and 6 months), 2 patients had subjective pain relief. When other therapies on intractable pain following spinal cord trauma are not effective, the DREZ-lesion might be considered.

Adult↗
PubMed1989

Prostaglandin E1 modifies porcine cerebral arterial tone through cyclooxygenase related eicosanoid(s) release.

The effects of prostaglandin E1 (PGE1) on porcine cerebral arteries were studied in the absence and presence of cyclooxygenase inhibitors, 5 x 10(-6) M indomethacin or 10(-4) M aspirin. In preparations placed at a resting tension, 3 x 10(-9) to 10(-6) M PGE1 caused dose-dependent contractions. In prostaglandin F2 alpha (PGF2 alpha)- contracted preparations, low concentrations of 10(-9) and 3 x 10(-9) M PGE1 did not modify arterial tone and higher concentrations of 10(-8) to 10(-6) M PGE1 further increased the arterial tone in all preparations tested. In contrast, in the presence of the cyclooxygenase inhibitors, low concentration of 10(-9) and 3 x 10(-9) M PGE1 markedly decreased the arterial tone induced by PGF2 alpha and higher dose of 10(-8) to 10(-6) M PGE1 increased the arterial tone in 15 of 18 preparations (83%). These findings suggest that PGE1 modifies porcine cerebral vascular tone at least partly through cyclooxygenase-related eicosanoid(s) production.

Animals↗
PubMed1989

NMR study on [1-13C]glucose metabolism in the rat brain during hypoxia.

The metabolism of [1-13C]glucose in the rat brain during hypoxia was investigated by 13C NMR spectroscopy. Male Wistar rats, weighing 100-120g, were anesthetized with ketamine (50 approximately 75 mg/kg i.p.) and ventilated mechanically with a mixture of 30% oxygen, 69.5% nitrogen and 0.5% halothane. [1-13C]glucose (250 mg/kg) was infused twice, at 10 minute intervals, through the femoral vein. For the control group (n = 4), the oxygen concentration of the inspiratory gas was maintained at 30% by vol throughout the experiments. For the hypoxia group (n = 6), the oxygen concentration in the inspiratory gas was reduced to 6-7% (93-94% nitrogen) and maintained for 30 min following [1-13C]glucose infusion. 13C NMR spectra were measured by a gated proton-decoupling method without a nuclear Overhauser effect. The [1-13C]glucose infusion gave apparent signals of the C1 carbon in the alpha- and beta-anomers of [1-13C]glucose at 92.7 and 96.7 ppm, respectively. Signals of the C2, C3 and C4 carbon atoms in glutamate and/or glutamine (glx) also appeared at 55, 27 and 34 ppm, respectively. The intensity of glx-C2 and glx-C3 signals increased later than that of glx-C4. The time lag between the different glx signals may reflect the turnover rate of the TCA cycle. Under the hypoxic condition, the signal of C3 carbon in lactate appeared at 21 ppm and increased. The alpha-glucose signal diminished during hypoxia, whereas the beta-glucose signal kept its intensity. The difference in changes of the signal intensity between alpha- and beta-glucose suggests that alpha-glucose is consumed more than beta-glucose in the hypoxic brain.

Animals↗