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Biomedical subjects

Y Tamari

Publications and source records attributed to Y Tamari.

At least 19 recordsLinked to original sources

Thermoregulation and hypothalamic histamine turnover modulated by interleukin-1 beta in rats.

To clarify the involvement of hypothalamic histamine in thermogenic response provoked by high ambient temperature, or interleukin-1 beta (IL-1 beta), changes in rectal temperature and histamine turnover were investigated. Rectal temperature was maintained normally after exposure to high ambient temperature, but elevated by IL-1 beta. In spite of these different responses of body temperature, hypothalamic histamine turnover was increased in each treatment. The results suggest that hypothalamic histaminergic neurons are activated not only peripherally by high ambient temperature, but also centrally by IL-1 beta as endogenous pyrogen.

Animals

2-deoxy-D-glucose suppresses food intake through activation of hypothalamic histamine in rats.

The aim of this experiment was to demonstrate whether brain histamine contributes to delayed suppression of food intake after administration of 2-deoxy-D-glucose (2-DG). Food intake decreased significantly for 48 h after infusion of 2-DG into the rat third cerebroventricle. This delayed decrease in food intake was abolished by depletion of neuronal histamine by intraperitoneal pretreatment with alpha-fluoromethylhistidine (160 mumol/rat), a suicide inhibitor of a histamine-synthesizing enzyme. Intracerebroventricular infusion of 24 mumol 2-DG accelerated turnover rate of hypothalamic histamine. These results indicate that the delayed feeding suppression by 2-DG is modulated through histaminergic neurons in the hypothalamus. This histaminergic response may be related, at least in part, to homeostatic control of energy metabolism in the brain.

Animals

The effects of pressure and flow on hemolysis caused by Bio-Medicus centrifugal pumps and roller pumps. Guidelines for choosing a blood pump.

Two Bio-Medicus BP-50 centrifugal pumps and two roller pumps were tested simultaneously with porcine blood at 21 degrees +/- 1 degree C in four in vitro circuits to determine the effect of four combinations of flow and pressure conditions on blood damage. Flows of 300 ml/min (1/4-inch inner-diameter tubing in the roller pump) and 1775 ml/min (1/2-inch inner-diameter tubing in the roller pump) and pressure differences across the pump (delta P = outlet pressure--inlet pressure) of 215 mm Hg (n = 6) and 345 mm Hg (n = 5) were examined. The index of hemolysis (milligrams plasma hemoglobin per 100 L blood pumped) for the BP-50 pump was higher at a flow of 300 ml/min than at a flow of 1775 ml/min (p < 0.0002). At 300 ml/min, the index of hemolysis for the BP-50 pump tended to be higher at 345 mm Hg than at 215 mm Hg (mean +/- standard error of the mean, 135 +/- 22 versus 88 +/- 9, p = 0.059). At 1775 ml/min, there was no difference in the index of hemolysis for the BP-50 pump between 215 and 345 mm Hg (37 +/- 7 versus 29 +/- 5, p = 0.32). With the roller pump, the index of hemolysis was higher at a flow of 300 ml/min than at a flow of 1775 ml/min (p < 0.036), but there was no difference in the indexes of hemolysis between 215 and 345 mm Hg at 300 ml/min (60 +/- 9 versus 61 +/- 11, p = 0.93) or at 1775 ml/min (40 +/- 6 versus 36 +/- 6, p = 0.61). Comparison between the two types of pumps showed that the index of hemolysis was significantly higher for the BP-50 than for the roller pump at a flow of 300 ml/min and a delta P of 215 mm Hg (88 +/- 9 versus 60 +/- 9, p = 0.009), as well as at a flow of 300 ml/min and a delta P of 345 mm Hg (135 +/- 22 versus 61 +/- 11, p = 0.001). At a flow of 1775 ml/min, there was no difference in the index of hemolysis between the two pumps at either pressure condition.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Characterization of leukaemic basophil progenitors from chronic myelogenous leukaemia.

We describe the unique characteristics of leukaemic basophils from a patient with chronic myelogenous leukaemia (CML). The leukaemic cells were immature basophil-like blasts and expressed CD4, CD7 and HLA-DR in addition to CD13 and CD33. Both immunoglobulin and T cell receptor genes were retained in germline configurations. Interleukin-1 (IL-1) or granulocyte-macrophage colony-stimulating factor (GM-CSF) as well as IL-3 or IL-4 enhanced the proliferation and differentiation of leukaemic cells and only basophils were generated from in vitro culture. These results suggest that basophil progenitors expressing CD4, CD7 and HLA-DR may be involved in the development of basophilic crisis of CML and that both IL-1 and GM-CSF may act on basophil progenitors as well as IL-3 or IL-4.

Antigens, CD

The effect of high pressure on microporous membrane oxygenator failure.

A retrospective study to determine the relationship between early microporous membrane oxygenator (MMO) failure and blood pressure at the MMO outlet (Pmo) was conducted using data collected with 19 dogs (22 +/- 1 kg, mean +/- SEM) undergoing routine normothermic cardiopulmonary bypass. Because gas flow was maintained at a high level, it could not be used to control CO2 exchange. Instead, blood PCO2 was controlled by adding CO2 to the sweep gas. Blood PO2 was controlled as suggested by the manufacturer, by adjusting the %O2 in the gas phase (g). Blood flow was 2575 +/- 54 ml/min; Pmo ranged from 173 to 790 mm Hg; and hematocrit was 33 +/- 1%. O2 exchange was calculated from blood gas parameters. Changes in the diffusion potential of O2 (delta PO2) and CO2 (delta PCO2) and MMO performance (P, taken as oxygen exchange normalized to a diffusion potential of 100 mm Hg) indicated MMO failure. Initial values, taken within 60 min of bypass initiation, were compared to final values taken at 226 +/- 9 min of bypass. Despite higher final delta PO2 (411 +/- 9 vs. 538 +/- 19 mm Hg, p less than 0.0001 paired t-test) and delta PCO2 (18.6 +/- 2.4 vs. 30.5 +/- 4.7 mm Hg, p less than 0.0017), arterial blood PO2 decreased (159 +/- 15 to 89 +/- 6 mm Hg, p less than 0.0005) and PCO2 increased (36.4 +/- 1.5 to 46.1 +/- 3.0 mm Hg, p less than 0.0039), and the performance decreased [24.5 +/- 1.1 to 20.1 +/- 0.7 (ml/min)/(100 mm Hg), p less than 0.0001].(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

[Successful treatment of a pretreated elderly case of small-cell lung carcinoma with continuous five-day intravenous infusion of cisplatin plus etoposide].

A 78-year-old man was admitted to our hospital with dyspnea in June 1988, and diagnosed as having small-cell lung carcinoma by cytological findings of pleural effusion. He was treated three times with CAV (cyclophosphamide, doxorubicin, vincristine) therapy and a partial response was achieved. In March 1989, he was again admitted complaining of right dull hypochondralgia accompanied by enlargement of primary tumor in the right lower lobe of the lung and metastases to mediastinal and intraabdominal lymph nodes. Because it was an aged and recurrent case, he was treated with continuous five-day infusion of etoposide, 30 mg/m2/day and CDDP, 18.5 mg/m2/day. After the second course, subjective symptoms clearly disappeared and swelling of mediastinal and intraabdominal lymph nodes was markedly reduced on computed tomography. No severe side effects except for moderate myelosuppression, alopecia and nausea were observed. This regimen appears useful in the treatment of small-cell lung carcinoma in elderly patients.

Aged

Bloodless testing for microporous membrane oxygenator failure: a preliminary study.

The use of a bloodless solution and high pressure to accelerate microporous membrane oxygenator (MMO) failure was investigated. It was hypothesized that albumin acts as a wetting agent, contributing to plasma leakage through the membrane, and that high MMO outlet pressure accelerates the process. Three MMO, B-Bentley BCM-40 (n = 7), M-Medtronic Maxima (n = 4), and S-Sarns 16310 (n = 7) were tested at 37 +/- 2 degrees C using three identical closed recirculating circuits and four conditions: 1) Lactated Ringer solution (LR) with MMO outlet pressure (Pmo) 750 mmHg; 2) LR + albumin (4 g/100 ml), Pmo 150 mmHg; 3) LR + albumin, Pmo 300 mmHg; and 4) LR + albumin, Pmo 750 mmHg. "Blood" flow and gas flow were maintained at 2 l/min. Failure was indicated when Na+ was detected in the effluent of the MMO exhaust gas. There were no failures without albumin in the solution. B and M showed no signs of failure under any of the test conditions at 78 hours. S failed at (mean +/- SEM) 4.9 +/- 1.0, 12.1 +/- 0.2, and 19 hours for conditions 4, 3, and 2 respectively. Preceding failure, inlet gas pressure increased more than eightfold (27 +/- 1 to 224 +/- 34 mmH2O). These preliminary results are similar to previous findings with blood and suggest that high MMO outlet pressure and the presence of albumin may promote plasma breakthrough for S. The combination may provide a basis for an accelerated bloodless test for MMO compatibility with long-term respiratory support.

Albumins

Fluorometry of nanogram amounts of selenium in biological samples.

For fluorometry of selenium in human blood, hair, and liver and in leaves, we wet-ashed the samples with conventional nitric and perchloric acids, and then extracted piazselenol (complex of Se and 2,3-diaminonaphthalene) in cyclohexane. Selenium was back-extracted from the cyclohexane into nitric acid to remove the fluorometric interferences of trace amounts of organic compounds. This fluorometric method is rapid and suitable for routine analysis. We applied the method to human hair samples and compared it with the data for non-destructive neutron activation analysis of the hair.

2-Naphthylamine

Neutron activation analysis of selenium and 17 elements in sediment.

Instrumental neutron activation analysis was performed to determine Na, Mg, Al, Cl, Sc, V, Cr, Mn, Fe, Co, Ni, Rb, Sb, Cs, Ba, Ce and Eu in the Pacific core sediment. Selenium was also determined by neutron activation analysis, by applying a solvent extraction method with 2,3-diaminonaphthalene (DAN) as a post-irradiation procedure, after the wet-ashing of the sediment. Homogeneity of trace constituents in the sediment and neutron flux corrections for accurate determination were also investigated.

Activation Analysis

Functional changes in platelets during extracorporeal circulation.

An in vitro trauma test was conducted to determine the effects of extracorporeal circulation on platelet count and function. Fresh human blood was circulated in two identical in vitro circuits for six hours at a rate of 500 ml per minute (500 recirculations). One circuit included a G.E.--Peirce membrane lung and the other was a control. Platelet aggregation induced by adenosine diphosphate (ADP), epinephrine, or collagen was studied before and after six hours of perfusion. No important drop in platelet count occurred in the control circuit (Control-C) following bypass, but there was a 20% drop for the lung circuit (Lung-C). Platelet aggregation was reduced by about 30% for the control circuit and 65% for the lung circuit. The large decrease in platelet function accompanied by only a moderate decrease in platelet count is discussed in terms of loss of the youngest and most active platelets, platelet inhibition due to ADP released by red blood cell lysis, and platelet trauma.

Adenosine Diphosphate

Effects of nicotine on salivary amylase secretion from rabbit parotid gland.

1. The effects of nicotine on amylase secretion induced by auriculo-temporal nerve stimulation were studied.2. Nicotine caused a transient increase in secretion as well as flow rate of amylase.3. No difference in nicotine action was found between acute sympathetic decentralization of the gland and acute denervation.4. The increase in amylase secretion due to nicotine was not inhibited by phenoxybenzamine, bretylium and chronic denervation, but was prevented by hexamethonium, propranolol and adrenalectomy.5. The increase in flow rate due to nicotine was not inhibited by propranolol, chronic denervation and adrenalectomy, but was prevented by hexamethonium, phenoxybenzamine and bretylium.6. These results show that the action of nicotine in increasing amylase secretion is neither a direct action on the ganglion nor on the nerve terminal of the cervical sympathetic nerve, but is an indirect action of catecholamines released from the adrenal medulla on the post-junctional receptors.7. The study also suggests that the initial acceleration of salivary flow due to nicotine is characterized by a mechanism different from that of amylase secretion.

Adrenal Medulla