[Ventilators which are designed for pressure support ventilation].
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Biomedical subjects
Publications and source records attributed to Y Usuda.
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We evaluated the influence of operative procedure on arterial ketone body ratio (AKBR), which indicates the function of the liver cells, in patients undergoing gastrectomy or mastectomy. AKBR during the stomach resection was significantly lower than that during the breast resection. A significant reduction in AKBR due to induced hypotension was observed in mastectomy group. SGOT and SGPT increased significantly in gastrectomy group, but unchanged in mastectomy group on the first and the seventh postoperative days. On the first post-operative day, SGOT and SGPT in gastrectomy group were significantly higher than those in mastectomy group. These findings suggest that influence of operative procedure on the liver during gastrectomy is more serious than that during mastectomy.
We studied a newly developed oral quinolone antimicrobial agent, levofloxacin (LVFX, DR-3355), and obtained the following results. 1. Serum and urine levels of LVFX were determined after oral administration of LVFX 100 mg to 11 elderly patients with various degrees of renal function insufficiencies. The patients were classified according to creatinine clearance (Ccr) values into Group I (n = 1, Ccr greater than or equal to 70 ml/min), Group II (n = 4, 40 less than or equal to Ccr less than 70 ml/min), and Group III (n = 6, Ccr less than 40 ml/min). The peak levels of LVFX did not differ greatly among the 3 groups, but in patients with severely impaired renal functions, serum concentrations decreased more slowly than in those with slightly and moderately impaired renal functions, and high serum levels were maintained over a long period. Urinary excretion of LVFX diminished in relation to degrees of renal failure. 2. LVFX was administered to treat 13 elderly patients with respiratory tract infections. Clinical responses were good in all patients with a high efficacy rate of 100%. Laboratory tests revealed eosinophilia in 1 case. The symptom was mild, however, and no severe side effects due to the drug were observed.
We evaluated the effects of hypocapnia on arterial oxygenation during induced hypotension with nitroglycerin (TNG) or prostaglandin E1 (PGE1) in patients undergoing mastectomy. Of the 20 patients studied, 10 belonged to TNG group and 10 belonged to PGE1 group. Mean arterial pressure during induced hypotension was maintained at 70% of the values observed before hypotension. A significant decrease in PaO2 was observed during hypotension under normocapnia (PaCO2 35-40 mmHg) in both groups. In addition, small but significant reduction in PaO2 from 128.5 +/- 23.7 mmHg to 122.5 +/- 25.5 mmHg in TNG group and from 129.9 +/- 11.9 mmHG to 116.7 +/- 15.6 mmHg in PGE1 group were induced by hypocapnia (PaCO2 27-30 mmHg) during hypotension. These findings suggest that usual dose of TNG and PGE1 might not or might partially inhibit hypoxic pulmonary vasoconstriction.
We evaluated the effect of prostaglandin E1 (PGE1) on arterial ketone body ratio (AKBR), which is a parameter to indicate the function of the liver cells, in the patients undergoing total or subtotal gastrectomy. Twenty patients were divided into two groups: continuous intravenous administration of PGE1 (0.02 micrograms.kg-1.min-1) was started from 30 minutes after the beginning of the operation in 10 patients, and the remainders did not receive PGE1. AKBR levels at 30 minutes after the beginning of the operation (during the resection of stomach) were significantly lower than those after the resection of stomach in both groups. A significant increase in AKBR caused by the administration of PGE1 was observed during the resection of the stomach in PGE1 group. However, almost no change was observed in AKBR during the resection of the stomach in control group. These findings suggest that the administration of PGE1 has a protective effect on liver which is due mainly to the increase in hepatic blood flow during the resection of stomach.
We examined the changes in the electromagnetically measured left lower lobe blood flow (QLLL) when the left lower lobe (LLL) was exposed to alveolar hypoxia selectively under two different positions (supine and right lateral position in 18 dogs. QLLL/CO, Qs/Qt and other cardiopulmonary parameters were obtained during the following experimental sequence; 1) the whole lung ventilated with 100% O2 (control), 2) LLL collapsed and the remainder ventilated with 100% O2, 3) N2 expansion of LLL (N2 CPAP) and the remainder ventilated with 100% O2, 4) O2 expansion of LLL (O2 CPAP) and the remainder ventilated with 100% O2, and 5) The whole lung ventilated with 100% O2. In the supine position group (n = 9), both selective collapse and N2 CPAP of LLL caused QLLL/CO to decrease significantly (P less than 0.02) from control values (14.9 +/- 1.7%) to 10.6 +/- 0.9% and 11.9 +/- 1.6%, respectively. But there was no difference in QLLL/CO between collapse and N2 CPAP of LLL. In the right lateral position group (n = 9), hypoxic exposure of LLL caused no decrease in QLLL/CO from control values. But QLLL/CO during N2 CPAP (8.5 +/- 1.1%) decreased significantly than that during collapse (10.8 +/- 1.5%) (P less than 0.02). Qs/Qt during N2 CPAP (15.6 +/- 1.4%) also decreased significantly (P less than 0.05) from that during collapse (18.5 +/- 2.2%). We conclude that the difference of the changes in QLLL/CO under hypoxic exposure between supine and right lateral position was caused by hydrostatic pressure which influenced more during lateral position than during supine position.
One of the general transcription factors, TFIIA, was purified to homogeneity from HeLa cell nuclear extracts by yeast TFIID affinity chromatography. Human TFIIA had a molecular weight of approximately 38 kd. It was able to associate with the complex formed by yeast TFIID and the TATA elements of the adenovirus E4 and ML promoters, and the HSP70 promoter. The association extended the protected region on each TATA element by yeast TFIID from DNase I digestion. Affinity-purified TFIIA was also able to stimulate transcription from the E4 and ML promoters in in vitro reconstituted systems.
The transcription factor ATF/E4TF3 stimulates transcription from the adenovirus early region 4 (E4) promoter by binding to specific promoter elements. Among the multiple forms of ATF/E4TF3, two forms with molecular masses of 47 and 43 kDa, which are most active in transcription in vitro from the E4 promoter, have been purified to homogeneity from HeLa cells by sequence-specific DNA affinity chromatography and biochemically characterized. Each purified protein formed a homodimer. These two homodimers were easily altered into a heterodimer when mixed together in the absence, but not in the presence, of the specific DNA sequence. All of these dimers were able to activate transcription in vitro from the E4 promoter by binding to the specific DNA sequence. Their activities to bind to DNA or stimulate transcription were different. The ability of the 47-kDa homodimer to stimulate transcription in vitro from the E4 promoter was approximately nine and three times higher than the abilities of the 43 kDa homodimer and the heterodimer, respectively, at the same level of DNA-binding activity. However, the affinity of the 47-kDa homodimer for DNA was lower than that of the 43-kDa homodimer, and the heterodimer had intermediate affinity. These results are the first to show differential binding and transcriptional activation activities of the different dimers of ATF/E4TF3, using purified cellular proteins rather than cloned gene products.
We studied relation between the serum potassium changes and the factors affecting serum potassium level during hepatic resection in 23 patients. Serum potassium concentration became significantly higher after hepatic resection. The magnitude of increase in serum potassium concentration showed a correlation with total clamping time of the right or left portal vein (r = 0.576, P less than 0.01) and also with the amount of blood transfused (r = 0.441, P less than 0.05), but no significant correlation was found with fall in pH and urine output during hepatic resection. These results suggest that the duration of clamping of portal vein play the key role in the increment in serum potassium concentration during hepatic resection.
Eight healthy males were studied to compare CO diffusing capacity (DLCO) during spontaneous breathing with that during continuous negative extra-thoracic pressure (CNETP). Mean DLCO was 33.0 +/- 5.1 ml.min-1.mmHg-1 during spontaneous breathing and 33.5 +/- 4.5 ml.min-1.mmHg-1 during CNETP with an end-expiratory negative extra-thoracic pressure (EENETP) of -20 cmH2O, and there was no significant difference between them (P less than 0.05). Pulmonary capillary blood volume, which was measured only in a male, was 76.7 ml during spontaneous breathing and 80.5 ml during CNETP. This change dose not seem to be significant. The results suggest that the effect of pulmonary diffusing capacity changes during EENETP on improvement of oxygenation may not be significant.
The effects of end-expiratory negative extra-thoracic pressure (EENETP) and PEEP on the ventilatory response to CO2 were studied in seven healthy volunteers. The changes in functional residual capacity during EENETP -20 cmH2O and PEEP 5 cmH2O were 13.9 and 12.9 ml.kg-1, respectively. The slopes of CO2 response (minute ventilation/end-tidal CO2) during ZEEP, EENETP and PEEP were 0.913, 0.622, 0.693 l.min-1.mmHg-1, respectively. The slopes during EENETP and PEEP were significantly decreased. These results indicate that EENETP and PEEP could worsen the CO2 response in patients with respiratory failure, especially, with chronic obstructive pulmonary disease in which functional residual capacity is increased.
Respiratory flow and chest wall motion during negative extrathoracic pressure ventilation (NETPV) were compared with those during spontaneous breathing in 8 healthy male volunteers. Chest wall motion was evaluated by separate measurement of the changes in the cross sectional area of rib cage and abdomen, using respiratory inductive plethysmograph. During NETPV, expiratory flow was characterized by a large peak and a rapid decline at the early expiratory phase. NETPV increased the relative contribution of rib cage motion to tidal ventilation, and induced the abdominal paradoxical movements at inspiration in two volunteers. These results indicate that NETPV augments rib cage motion rather than abdominal motion, and this altered mechanics of chest wall may change intrapulmonary distribution of inspired gas.
Arterial blood-gases were evaluated before, during and after the vasodilator induced hypotension in patients undergoing mastectomy. Forty-two patients studied were anesthetized with halothane and nitrous oxide in oxygen. They were divided into following four groups according to vasodilators used: trimetaphan (TMP), nitroglycerin (TNG), adenosine triphosphate (ATP), and prostaglandin E1 (PGE1). Significant reduction in PaO2 was observed during induced hypotension in all groups. However, there was no difference in the degree of PaO2 decrease among four groups. A small but significant increase in PaCO2 and a decrease in pH were observed during and/or after hypotension with TNG and PGE1. These findings suggest that induced hypotension may impair the pulmonary gas exchange by decreased cardiac output and/or change in ventilation-perfusion ratio regardless of vasodilators used. Therefore, continuous arterial blood-gas monitoring should be desirable under these conditions.
Eight patients, of ASA physical status I or II soon after total knee replacement under general anesthesia, were studied to compare negative extra-thoracic pressure ventilation (NETPV) with positive airway pressure ventilation (PAPV). The measured parameters during the two ventilatory modes were tidal volume, arterial blood gas and functional residual capacity change (delta FRC). Tidal volume obtained during NETPV was 60 to 80% of that during PAPV at the same absolute values of peak pressure. delta FRC obtained during NETPV was 30 to 40% of that during PAPV at the same absolute values of end-expiratory pressure. A decrease in the esophageal pressure was 4 to 11cmH2O at an end-expiratory negative extra-thoracic pressure of -10 to -20 cmH2O. When the patients were ventilated with the same values of minute ventilation on NETPV and PAPV, there was no significant difference in blood gas values. These findings suggest that efficiency of NETPV is less than that of PAPV at the same absolute working pressure but pulmonary gas exchange of NETPV is almost equal to that of PAPV at the same minute ventilation in the normal lung.
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Arterial blood ketone body ratio (AKBR; acetoacetate/beta-hydroxybutyrate) is known as a parameter to indicate the function of the liver cells. We evaluated the effects of induced hypotension with prostaglandin E1 (PGE1) or trimetaphan (TMP) on AKBR in patients without liver disease undergoing mastectomy. Almost no change was observed in AKBR before, during and after hypotension with PGE1, but slight diminution was observed during hypotension with TMP. No hepatic dysfunction, however, developed in these patients postoperatively. These findings suggest that usual hypotension with TMP may provoke no postoperative hepatic dysfunction in patients without liver disease. For the patient who required either hypotension of long duration or hypotension with other factors affecting function of liver (surgical procedures, drugs and others), we prefer PGE1 to TMP as a hypotensive drug. We should also adopt PGE1 when cardiovascular control with hypotensive drug is necessary in patients with liver disease.
A 57-year-old man was given 40 mg of activated carbon aclacinomycin (ACM) emulsion into mesenteric lymph nodes during anesthesia with enflurane, nitrous oxide, oxygen and epidural anesthesia. He had no complications preoperatively. Immediately after the injection, his skin turned to red, and 5 minutes later, sinus tachycardia, R wave amplitude reduction, T wave amplitude elevation, QT prolongation and PVCs were noted, and then, ventricular fibrillation (Vf) occurred 15 minutes after the injection. We succeeded in electrical defibrillation within about 180 seconds. At that time, both arterial blood gas and electrocytes were normal. Serum ACM concentration was remarkably elevated 60 minutes after the administration, and remained high 22 hrs later. Postoperative course was uneventful and he was discharged on the 17th postoperative day. It has been said that ACM has relatively low cardiotoxicity compared with adriamycin because of rapid distribution and metabolism. However, it might cause cardiac complication such as ECG abnormality, heart failure, pericarditis, though the effects are transient and reversible. Therefore we should be ready for its rapid treatment. Coenzyme Q10 could counteract cardiotoxicity of ACM.
We examined the factors which influence the postoperative liver function in the gastric cancer patients who received gastrectomy by a particular surgeon. One hundred and five patients had no history of liver diseases, no blood transfusions, and no infection after the operation. They also had normal liver function preoperatively. They were anesthetized with halothane-nitrous oxide oxygen or enflurane-nitrous oxide oxygen with epidural anesthesia by the same group of anesthesiologists. GOT was followed for one month after the operation to evaluate the liver function. In 44 patients, GOT went up to above 50 IU.l-1. The maximal GOT correlated with low hemoglobin level on the 1st postoperative day, the duration of hypotension below 80 mmHg of the systolic blood pressure, and duration of the operation. These results suggest that special attention should be paid to correct hemoglobin level and to avoid hypotension during anesthesia.