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Biomedical subjects

H Katsuya

Publications and source records attributed to H Katsuya.

At least 19 recordsLinked to original sources
PubMed1998

Effect of propofol on norepinephrine-induced increases in [Ca2+]i and force in smooth muscle of the rabbit mesenteric resistance artery.

BACKGROUND: Propofol (2,6-diisopropylphenol) possesses vasodilating activity in vivo and in vitro. The propofol-induced relaxation of agonist-induced contractions in small resistance arteries has not been clarified. METHODS: The effect of propofol was examined on the contractions induced by norepinephrine and high K+ in endothelium-denuded rabbit mesenteric resistance artery in vitro. The effects of propofol on the [Ca2+]i mobilization induced by norepinephrine and high K+ were studied by simultaneous measurement of [Ca2+]i using Fura 2 and isometric force in ryanodine-treated strips. RESULTS: Propofol attenuated the contractions induced by high K+ and norepinephrine, the effect being greater on the high K+-induced contraction than on the norepinephrine-induced contraction. In Ca2+-free solution, norepinephrine produced a transient contraction resulting from the release of Ca2+ from storage sites that propofol attenuated. In ryanodine-treated strips, propofol increased the resting [Ca2+]i but attenuated the increases in [Ca2+]i and force induced by both high K+ and norepinephrine. In the presence of nicardipine, propofol had no inhibitory action on the residual norepinephrine-induced [Ca2+]i increase, whereas it still modestly increased resting [Ca2+]i, as in the absence of nicardipine. CONCLUSIONS: In smooth muscle of the rabbit mesenteric resistance artery, propofol attenuates norepinephrine-induced contractions due to an inhibition both of Ca2+ release and of Ca2+ influx through L-type Ca2+ channels. Propofol also increased resting [Ca2+]i, possibly as a result of an inhibition of [Ca2+]i removal mechanisms. These results may explain in part the variety of actions seen with propofol in various types of vascular smooth muscle.

Anesthetics, Intravenous↗
PubMed1998

[Effects of ulinastatin on PMNL and vascular endothelial injury in patients undergoing open heart surgery with CPB].

Activated leukocytes are thought to contribute to respiratory dysfunction, alterations in microvascular permeability, disseminated intravascular coagulation, and thrombosis, all of which can complicate cardiopulmonary bypass (CPB). We have measured the levels of circulating proinflammatory cytokines (IL-6, 8), polymorphonuclear leukocytes elastase (PMNL-E), and vascular endthelial factors (ET-1, TM, sICAM-1) in patients undergoing open heart surgery with CPB. Patients were divided into a control group and a ulinastatin group. We have examined the effects of ulinastatin on these humoral mediators and postoperative pulmonary function. Every factor except IL-8 increased after CBP in control group. IL-6 and PMNL-E declined sharply to normal level in a few hours, but it took several days after surgery for ET-1, TM, and sICAM-1 to return to preoperative levels. Ulinastatin significantly suppressed the elevation of PMNL-E after CPB, indirectly suppressing the increase of other factors. There was no significant relationship between levels of humoral mediators and postoperative pulmonary function between the two groups. Our results suggest that ulinastatin alleviates the damage of vascular endothelium due to CPB (first attack), and this may be beneficial to reduce excessive inflammatory reaction against secondary insults.

Aged↗
PubMed1998

[Anesthetic management for microlaryngeal surgery with high frequency jet ventilation and intravenous application of pentazocine and propofol].

Microlaryngeal surgery was performed with total intravenous anesthesia using pentazocine and propofol in 20 patients. The patients were paralyzed by suxamethonium infusion and ventilated by high frequency jet ventilation via the laryngoscope. In place of the opioid analgesics commonly used in TIVA for microlaryngeal surgery, pentazocine was given. All but one of the patients received pentazocine 15 m.g. intramuscularly as a premedication and then another 15 m.g. intravenously for induction of anesthesia. Average time of surgeries was 33.6 minutes. Average doses of pentazocine and suxamethonium given during surgeries were 369 m.g. and 286 m.g., respectively. This technique allowed stable anesthesia to be achieved with rapid postoperative recovery, without serious complications like intraoperative return of awareness.

Adjuvants, Anesthesia↗
PubMed1992

An initial comparison of intensive care in Japan and the United States.

OBJECTIVE: The objective of this study was to compare the utilization of, and outcome from, critical care services in selected medical centers providing secondary and tertiary care in the United States and Japan. DESIGN: Prospective data collection on 1,292 patients from each of the participating Japanese study hospitals in 1987 to 1989 and compared with the 5,030 patients in the United States 1982 Acute Physiology and Chronic Health Evaluation (APACHE II) database used to develop the APACHE II equation. Detailed organizational characteristics of the participating ICUs and hospitals were also obtained. SETTING: Data collection took place in the ICUs of 13 U.S. hospitals and six Japanese hospitals. PATIENTS: Data were collected on consecutive, unselected patients from medical, surgical, and mixed medical/surgical critical care units, with a spectrum of medical and surgical diagnoses. MEASUREMENTS AND MAIN RESULTS: U.S. and Japanese ICUs have a similar array of diagnostic and therapeutic modalities. Only 2% (range 0.6 to 3.5) of beds in Japanese hospitals were designated to intensive care. The organization of the Japanese and U.S. ICUs varied by hospital. There were significantly fewer women admitted to Japanese ICUs and a substantially lower proportion of low-risk-of-death patients. Despite a rapidly aging population, there were relatively fewer elderly patients with chronic health ailments in the Japanese ICU population (8%) compared with the U.S. cohort (18%). CONCLUSIONS: In this sample of hospitals, similar high-technology critical care is available in the United States and Japan. Variations in utilization between the two countries represent differences in case mix and bed availability. The APACHE II equation stratified patients in the Japanese patient cohort across the full spectrum of increasing severity of illness.

Chi-Square Distribution↗
PubMed1992

[Influence of thiopental administration on peripheral circulation during cardiac surgery with extracorporeal circulation].

The influence of thiopental administration on peripheral circulation during cardiac surgery with extracorporeal circulation was examined. The subjects were 28 patients who were divided into one group of 14 patients receiving thiopental and the other group of 14 patients receiving no thiopental. The time lag of changes in peripheral temperature (sole) from that in central temperature (forehead) according to the deep body temperature determination, and base excess were used as indices of the quality of the peripheral circulation. A single shot of thiopental at a dose of 4 mg.kg-1 was initially given i.v. at the start of extracorporeal circulation and subsequently thiopental at a dose of 2 mg.kg-1.hr-1 was continuously infused i.v. up to the time of the aortic declamping. The results indicate a significantly smaller lag in the group receiving thiopental than in the group receiving no thiopental. Base excess was maintained within normal limits in the former group compared with negative base excess in the latter group as well as a significantly smaller requirement of postoperative catecholamine in the former group. The above findings suggest that thiopental administration during cardiac surgery with extracorporeal circulation is not only useful for maintaining peripheral circulation, but also beneficial for post-operative cardiac function.

Aged↗
PubMed1990

Surfactant therapy for pulmonary edema due to intratracheally injected bile acid.

Intratracheally injected bile acid has been shown to produce severe pulmonary edema. We investigated the therapeutic effect of an exogenous surfactant for aspirated bile acid. Anesthetized rabbits were injected intratracheally with 1 ml/kg body weight of taurocholic acid, diluted to 0.6% with normal saline solution. After the injection of taurocholic acid, the PaO2 values decreased, the PaCO2 values increased, and abnormal shadows appeared in chest x-rays. After surfactant injection, the rabbits improved, but pulmonary edema recurred after one hour. After additional injection of the surfactant, the improved condition was sustained for 6 h. All animals in the untreated group died within 5 h and were shown to have severe pulmonary edema. Conversely, microscopic examination revealed no pulmonary edema in animals surviving 6 h after surfactant treatment. Thus, exogenous surfactant can prevent damage to the lung caused by intratracheally injected bile acid.

Animals↗
PubMed1989

Simple and noninvasive indicator of pulmonary gas exchange impairment using pulse oximetry.

We postulated that the fractional inspired oxygen concentration (FIO2) required to achieve a certain value of arterial oxygen saturation (SaO2) can be used as an indicator of pulmonary gas exchange impairment in patients during mechanical ventilation. We tested this hypothesis in 20 patients. By reducing FIO2 in increments of 10 vol% of capacity while monitoring SaO2 with pulse oximetry, we could determine FI98, FI97, FI96, and FI95; that is, the FIO2 that yields 98, 97, 96, and 95% SaO2, respectively. On the basis of our data, we chose FI98 as the most appropriate index, as an SaO2 of 97% or below could not be achieved even with a low FIO2 in some of the patients. To test the significance of the newly proposed index, we compared FI98 with the alveolar-arterial oxygen tension difference, P(A - a)O2, and with the respiratory index, which are routinely used elsewhere. The correlation between FI98 and P(A - a)O2 was excellent: P(A - a)O2 = 490.5 * FI98 + 117.2 with a correlation coefficient of 0.906 (P less than 0.01). FI98 also correlated significantly with the respiratory index: respiratory index = 4.354 * FI98 - 0.776 (r = 0.889, P less than 0.01). We conclude that FI98 may be used as a simple index for the rough estimation of pulmonary gas exchange impairment without the need for invasive procedures. However, further studies are needed to confirm the validity of our method in hemodynamically unstable patients or when other brands of pulse oximeters are used.

Adolescent↗
PubMed1989

Complement activation and neutrophil dysfunction in burned patients with sepsis--a study of two cases.

The changes in complement components and neutrophil functions were investigated in two cases of flame burn patients who died of multiple organ failure following septic shock. In the period of bacteremia, complement activation was observed in the plasma of both patients, using an immunoblotting method demonstrating C3a-related antigens. Coincidently, reduced neutrophil function and a decrease in the superoxide and leukotriene producing capacity, were also observed. An in vitro study showed that the capacity to produce superoxide and leukotriene became reduced in normal neutrophils after exposure to complement activated serum. These observations suggested that complement activation, probably brought about by massive bacterial infection, induced the impairment of neutrophil functions and resulted in a further breakdown of the host defence system, thereby leading to sepsis.

Adult↗
PubMed1989

[Emergency cardiopulmonary bypass for cardiopulmonary-cerebral resuscitation].

Cardiopulmonary bypass (C-P bypass) was performed on two patients who had not responded to conventional cardiopulmonary resuscitation (CPR). The first patient, a 56-y-o male, with bilateral pulmonary thromboembolism repeatedly underwent cardiac massage and electric defibrillation for recurrent ventricular fibrillation. A veno-arterial bypass route was prepared during cardiac massage, and bypass circulation was started 3 hours after the onset of the first ventricular fibrillation. Soon after the initiation of C-P bypass, the physical status and EEG of the patient improved. The patient regained consciousness within a few hours and later underwent open chest pulmonary embolectomy. The second patient, a 44-y-o male, developed refractory cardiogenic shock near the end of aortocoronary bypass graft operation. Under closed chest massage, a femoro-femoral cardiopulmonary bypass operation was started. Soon after the initiation of the bypass circulation and IABP, peripheral circulation improved markedly, and consciousness returned within several hours. Though the first patient finally died from far advanced pulmonary embolism, he was conscious as long as the C-P bypass was continued for two days. In the second patient, the cardiac function gradually improved after the 3rd day. C-P bypass was tapered and discontinued on the 5th day. Emergency veno-arterial bypass for CPR is effective means to maintain life until the cardiopulmonary and cerebral functions are restored. Recent advances in emergency C-P bypass are introduced and a new acronym extracorporeal lung and heart assist, ECLHA, is proposed. Emergency ECLHA with veno-arterial cannulations through percutaneous puncture will become a promising adjunct of cardiopulmonary-cerebral resuscitation in the near future.

Adult↗
PubMed1989

[Hemodynamic effects of extubation of an endotracheal tube in patients following cardiac surgery--inspiratory or expiratory phase?].

The question whether an endotracheal tube should be removed in the inspiratory phase or in the expiratory phase is still controversial. Hemodynamic effects of extubation at each phase were compared in 14 patients following cardiac surgery. In the patients who were extubated in the expiratory phase, marked changes in heart rate (HR), systolic arterial pressure (SAP), mean arterial pressure (MAP), and rate pressure product (RPP) were observed at one, five and 10 minutes after the extubation. In the patients whose endotracheal tubes were removed in the inspiratory phase, only small changes in SAP, MAP and RPP were observed at one and five minutes after the extubation. Since hemodynamic changes after cardiac surgery must be prevented as much as possible, we may conclude that the endotracheal tube should be removed in the inspiratory phase.

Aged↗
PubMed1984

Successful treatment of thyrotoxic crisis with plasma exchange.

A 36-yr-old woman with thyroid storm was successfully treated with plasma exchange. After the first plasma exchange, free serum thyroxine (T4) was decreased and serum thyroxine-binding globulin (TBG) was significantly increased. The decrease in the patient's free T4 level after plasma exchange can perhaps be attributed to T4's increased binding capacity. Plasma exchange may be an effective therapy for thyrotoxic crisis and should be performed immediately if conventional therapy fails to improve the patient's condition.

Adult↗