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Biomedical subjects

T Shimazu

Publications and source records attributed to T Shimazu.

At least 163 records · Page 9Linked to original sources
PubMed1989

The use of continuous spinal anesthesia in severe tetanus with autonomic disturbance.

Eight patients with severe tetanus experienced episodes of marked cardiovascular instability. During these unstable periods, cardiac output and vascular resistance varied independently. Beta blocking and low doses of ganglionic blocking agents failed to control cardiovascular instability even when combined. High doses of ganglionic blockers stabilized hemodynamics for a short period, but caused the elevation of transaminases. After unsuccessful treatment with cardiovascular drugs, continuous spinal anesthesia (CSA) was applied to five patients. For 5 to 23 days circulation was regulated artificially under complete blockade of the autonomic nervous system by infusing isotonic 0.5% bupivacaine intrathecally. Catecholamine was added intravenously to maintain adequate blood pressure. Before the introduction of CSA, three patients died of circulatory failure. In contrast, CSA dramatically suppressed the cardiovascular instabilities, and all five treated patients survived. This suggests that both sympathetic and parasympathetic nervous systems need to be blocked to stabilize hemodynamics in severe tetanus.

Adult↗
PubMed1989

False-positive result in Limulus test caused by Limulus amebocyte lysate-reactive material in immunoglobulin products.

Limulus amebocyte lysate (LAL)-reactive material other than endotoxin was detected in the plasma and urine of patients after intravenous immunoglobulin therapy. Thirty-seven vials of six different immunoglobulin products were analyzed for the LAL-reactive material by combined use of a conventional chromogenic Limulus test and a chromogenic endotoxin-specific test. The amount of LAL-reactive material in reconstituted immunoglobulin solutions ranged from a mean (standard deviation) of 10.2 (2.1) to 2,448.1 (988.9) pg/ml, and there were statistically significant differences among the six brands. The levels of LAL-reactive material in plasma increased in proportion to the amounts contained in the immunoglobulin products administered. The material accumulated in the blood with repeated administration. Urinary excretion of the material was less than 5% of the total amount administered. Such material seems to be derived from the cellulose-based membranes used during preparation of the blood products. Thus, interpretation of Limulus test results of patients receiving immunoglobulin therapy requires special consideration.

Adult↗
PubMed1989

Metabolic and sympathetic nerve activities of brown adipose tissue in tube-fed rats.

To investigate possible contribution of oropharyngeal factors to thermogenesis in brown adipose tissue (BAT), rats were given a liquid diet orally or through a gastric tube for 4-12 days. Tube-fed rats weighed more and had heavier white adipose tissue than orally fed rats, although they were given the same amount of the diet. Triglyceride content of the interscapular BAT was higher in tube-fed rats, but the rate of fatty acid synthesis was lower than those in orally fed rats. Uptake of 2-deoxyglucose (2DG), an index of glucose utilization, in BAT was also lower in tube-fed rats. Surgical sympathetic denervation of BAT reduced both lipogenic activity and 2DG uptake to abolish the differences in these metabolic activities between tube-fed and orally fed rats. Sympathetic nerve activity in the BAT assessed from the turnover rate of norepinephrine in the tissue was lower in tube-fed rats. The results suggest that there is a sympathetically mediated mechanism dependent on afferent input from oropharyngeal receptors to regulate BAT thermogenesis and that greater fattening seen after tube feeding may be attributable to a decreased BAT thermogenesis because of the absence of food-induced sensory stimulation.

Adipose Tissue, Brown↗
PubMed1988

Hypothalamic regulation of histidyl-proline diketopiperazine binding sites in the rat liver.

The effects of hypothalamic hormones and electrolytic lesioning of the ventromedial hypothalamic nuclei (VMH) on histidyl-proline diketopiperazine (cyclo(His-Pro] binding in the rat liver were studied. VMH-lesioning markedly decreased cyclo(His-Pro) binding in the liver. Scatchard analysis revealed that the loss of cyclo(His-Pro) binding induced by VMH lesioning was due to a decrease in the number and affinity of binding sites. Somatostatin (SS) administration decreased cyclo(His-Pro) binding. The SS-induced changes in cyclo(His-Pro) binding were due to changes in the binding affinity. On the other hand, the administration of TRH or LH-RH did not affect cyclo(His-Pro) binding in the liver, although cyclo(His-Pro) has been proposed to be a metabolite of TRH. These findings suggest that the hypothalamus may regulate the cyclo(His-Pro) binding sites in the liver probably by controlling pancreatic SS secretion, since a VMH-lesion is reported to cause hypersecretion of pancreatic SS.

Animals↗
PubMed1988

Effects of ventromedial and lateral hypothalamic stimulation on chemically-induced liver injury in rats.

The effects of hypothalamic stimulation on experimental liver injury induced by carbon tetrachloride (CCl4) or dimethylnitrosamine (DMN) were studied in rats, by measuring plasma alanine aminotransferase (ALT) activity as an index of acute liver injury. Electrical stimulation of the ventromedial hypothalamus (VMH) in CCl4-treated rats caused a marked increase in plasma ALT activity, accompanied by a significant decrease in ALT activity in the liver, although CCl4 treatment alone had no significant effect on plasma ALT activity. A similar effect of VMH stimulation on plasma ALT activity was observed in rats treated with DMN, another hepatotoxic chemical. No such exaggerated effect of VMH stimulation on plasma ALT activity was observed after stimulation of the lateral hypothalamic area (LH). Surgical sympathetic denervation of the liver greatly suppressed the increase in plasma ALT activity after CCl4 injection and VMH stimulation. Measurement of regional blood flow indicated that VMH stimulation did not produce a significant change in blood flow to the liver. These results suggest that the VMH is involved in the progress of chemically-induced liver injury through activation of the sympathetic nerve (hepatic nerves), possibly by affecting liver metabolism more than the blood flow change to the liver.

Alanine Transaminase↗
PubMed1988

Liver phosphorylase activation during early phase of feeding behavior: a neurohumoral regulation.

The mechanisms of liver glycogen depletion during the early phase of spontaneous feeding were examined in adult rats. A 40% increase in the activity of phosphorylase a, the active form of a key glycogenolytic enzyme, was detected 5 min after the onset of feeding, with a concomitant decrease of glycogen in the liver after 5 and 15 min. Within 60 min after the onset of feeding, the enzyme activity returned to the basal level and the glycogen content was restored. These metabolic responses were impaired by hepatic sympathetic denervation or by bilateral adrenodemedullation. It was concluded that the onset of meals may evoke an arousal of the sympathoadrenal system including the hepatic innervation, and that activation of this system is important in stimulating liver phosphorylase activity and glycogenolysis during the early phase of spontaneous feeding.

Adrenal Medulla↗
PubMed1988

Tracheobronchial rupture caused by blunt chest trauma: acute respiratory management.

The clinical management of 12 patients with major intrathoracic tracheobronchial rupture (complete, 3; incomplete, 9) due to blunt trauma has been reviewed and compared with that of two groups of patients with chest injuries not involving the tracheobronchial tree, 17 patients with multiple rib fractures and 17 with chest injuries requiring thoracotomy for control of pneumothorax and hemothorax. The effect of injury on ventilatory function was significantly greater in the patients with tracheobronchial injury in whom an elevated PCO2 at the time of admission was associated with a poor prognosis. Conventional ventilatory management with endotracheal intubation and positive pressure ventilation causing increased air leakage produced further deterioration of pulmonary function in four of the patients with tracheobronchial disruption. The use of a double-lumen endobronchial tube in two patients with tracheobronchial rupture facilitated ventilatory support and subsequent operative management.

Adolescent↗
PubMed1988

Monoclonal antibodies recognizing different epitopes of the 27-kDa gap junction protein from rat liver.

Monoclonal antibodies (2-3E2, 6-3G11, and 7-3H6) against gap junction plaques purified from rat liver were prepared and characterized. Immunoblot analysis of liver gap junctions revealed that all three antibodies reacted with the 27-kDa protein, but not with the 22-kDa one. The 2-3E2 and 6-3G11 antibodies both reacted with the 27-kDa protein in gap junctions purified from livers of the rat, mouse, rabbit, and guinea pig; the 7-3H6 antibody, however, failed to react with the 27-kDa protein from guinea pig liver. The 7-3H6 antibody reacted strongly with the 24- to 26-kDa degradation products of the 27-kDa protein. Indirect immunofluorescence showed that the 6-3G11 and 7-3H6 antibodies both gave the same specific fluorescence labeling on rat liver cryosections, suggesting that these two antibodies recognized the cytoplasmic sites of the 27-kDa protein. Immunoblot analysis of protease-digested fragments from the 27-kDa protein revealed that the 7-3H6 antibody reacted with the 24- and 17-kDa fragments (including portions of the carboxyl-terminal domain of the 27-kDa protein) produced with endoproteinases Arg-C and Lys-C, respectively. Immunoblot analysis of CNBr fragments of the 27-kDa protein revealed that all three antibodies reacted with the 10-kDa fragment, which is thought to be the carboxyl-terminal domain of the 27-kDa protein. These results demonstrate that three monoclonal antibodies recognize different epitopes of the cytoplasmic sites (probably the carboxyl-terminal domain) of the 27-kDa liver gap junction protein.

Animals↗
PubMed1988

Early diagnosis of invasive candidiasis and rapid evaluation of antifungal therapy by combined use of conventional chromogenic limulus test and a newly developed endotoxin specific assay.

Since beta-1,3-glucan is a common component of fungal cell wall, its detection might be useful in diagnosing invasive candidiasis. Not only endotoxin but beta-1,3-glucan activates proclotting enzyme contained in a conventional chromogenic limulus test (CCLT). Endotoxin activates this enzyme through factor C, while the beta-1,3-glucan activates through factor G. Since endotoxin specific test (EST) contains factor C, endotoxin would be quantified. By subtracting EST value from CCLT value, beta-1,3-glucan would be quantified. We named this value Fungal Index (FI), and examined if it actually reflects the candidal infection. Ninety-two patients were tested for CCLT and EST prospectively. FI increased significantly in candidal infection (p less than 0.05) but remained low in GNR infection. Moreover, FI increased proportionally to the severity of candidal infection. Elevated FI decreased when antifungal therapy was successful. Thus FI was a useful index not only in the diagnosis of invasive candidiasis but also in the evaluation of antifungal therapy.

Antifungal Agents↗
PubMed1988

Sympathetic activation of lipid synthesis in brown adipose tissue in the rat.

1. The roles of the sympathetic nerves in regulating lipid synthesis in brown adipose tissue (BAT) were studied by measuring incorporation of 3H from 3H2O into glyceride glycerol and glyceride fatty acids in the interscapular BAT in anaesthetized rats. 2. When noradrenaline was infused intravenously at a total dose of 1-8 micrograms/100 g body weight over 30 min, 3H incorporation into glyceride glycerol increased whereas 3H incorporation into fatty acids did not change. Similar responses were found when the sympathetic nerves entering the interscapular BAT were stimulated continuously at 10 Hz. However, when electrical stimuli consisting of a much shorter train (2 s) were applied to the nerves at 3 min intervals at 10 Hz (stimulation in bursts). 3H incorporation into both glyceride glycerol and fatty acids was enhanced. Stimulation in bursts elicited more pronounced lipogenic responses than other patterns that were employed, and involved the delivery of precisely the same number of impulses over the whole period of stimulation. The lipogenic responses to nerve stimulation in bursts were increased by increasing the stimulus frequency over the range 4-40 Hz. 3. Simultaneous administration of propranolol and phenoxybenzamine had little effect on either the fatty acid or the glyceride glycerol response to nerve stimulation. In contrast, these blocking agents almost completely eliminated the responses to noradrenaline infusion. 4. Pre-treatment with guanethidine effectively abolished the lipogenic response to nerve stimulation but potentiated the response to noradrenaline infusion. 5. It is concluded that lipid synthesis in BAT is enhanced by direct electrical stimulation of the sympathetic nerves only when they are stimulated in bursts. Sympathetic activation of lipogenesis in BAT is not solely attributable to the action of noradrenaline but involves some non-adrenergic mechanism.

Adipose Tissue↗
PubMed1987

Ventromedial hypothalamic stimulation accelerates norepinephrine turnover in brown adipose tissue of rats.

To establish a functional link between the ventromedial hypothalamus (VMH) and brown adipose tissue (BAT), effects of electrical stimulation of the VMH and the lateral hypothalamus (LH) on norepinephrine (NE) turnover in the interscapular BAT were examined in rats. Stimulation of the VMH elicited about 3-fold increase in the rate of NE turnover in BAT, whereas stimulation of the LH had no appreciable effects. The effect of VMH stimulation was abolished after sympathetic ganglion blockade or by surgical sympathetic denervation of BAT. It was concluded that there is a sympathetic nerve-mediated connection between the VMH and BAT, and that stimulation of the VMH induces metabolic activation and heat production in BAT through an increase in sympathetic nerve activity.

Adipose Tissue, Brown↗
PubMed1987

Long-term continuous spinal anesthesia in severe tetanus with autonomic disturbance.

The mortality rate from tetanus is still high if the disease is accompanied by signs of autonomic nervous system dysfunction. We treated a 75-year-old woman with tetanus and autonomic dysfunction with continuous high spinal anesthesia for 23 days. She recovered. Spinal anesthesia may be a useful adjunct for the treatment of severe tetanus.

Aged↗
PubMed1987

Phosphorylation of liver gap junction protein by protein kinase C.

The 27 kDa protein, a major component of rat liver gap junctions, was shown to be phosphorylated in vitro by protein kinase C. The stoichiometry of the phosphorylation indicated that approx. 0.33 mol phosphate was incorporated per mol 27 kDa protein. Phosphorylation was entirely dependent on the presence of calcium and was virtually specific for serine residues. For comparison, the gap junction protein was also examined for its phosphorylation by cAMP-dependent protein kinase, the extent of phosphorylation being one-tenth that exerted by protein kinase C.

Animals↗
PubMed1987

Effect of ventromedial hypothalamic stimulation on blood flow of brown adipose tissue in rats.

The changes in regional blood flows to the rat's interscapular brown adipose tissue and several other tissues during electrical stimulation of the ventromedial hypothalamus (VMH) were studied using radioactively labelled microspheres. Measurement of blood flow was carried out, along with monitoring heart rate, under anesthesia and at thermoneutrality. During VMH stimulation the heart rate was clearly augmented and cardiac output increased about 45%. Regional blood flows were significantly increased in response to VMH stimulation in interscapular brown adipose tissue, adrenal glands, diaphragm and gastrocnemius muscles. The response of interscapular brown adipose tissue was the most prominent (approx. fifty-fold increase). Blood flows tended to decrease in spleen, lungs and kidneys during VMH stimulation, but did not change in liver or in other visceral organs. These observations suggest that the VMH is concerned with the regulation of regional blood flow to brown adipose tissue and contributes to thermogenesis in this tissue.

Adipose Tissue, Brown↗