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Biomedical subjects

O Uchida

Publications and source records attributed to O Uchida.

14 recordsLinked to original sources

Clinical evaluation of cerebral oxygen balance during cardiopulmonary bypass: on-line continuous monitoring of jugular venous oxyhemoglobin saturation.

To prevent brain damage during cardiopulmonary bypass (CPB), adequate cerebral perfusion for cerebral oxygen demand should be maintained. We monitored jugular venous oxyhemoglobin saturation (SjO2), which reflects the overall balance of cerebral oxygen supply and demand, continuously in 12 patients undergoing cardiac surgery. We examined whether this balance is disrupted during CPB, and if so, analyzed critical factors that affect this phenomenon. At the initiation of CPB, in spite of a significant decrease in mean arterial pressure, SjO2 did not change, and it was stable during the hypothermic period of CPB. On the other hand, a significant reduction in SjO2 was observed during the rewarming period, and SjO2 had an inverse linear correlation with nasopharyngeal temperature. Furthermore, the percent decrease of SjO2 was significantly related to "rewarming speed" (an average increase in temperature per minute). Our results indicate that temperature change during the rewarming period is a critical factor affecting the balance of cerebral oxygen supply and demand during CPB.

Adult

Internal jugular vein catheterization in infants undergoing cardiovascular surgery: an analysis of the factors influencing successful catheterization.

Central venous catheterization for pressure monitoring and drug administration is often important in the anesthetic management of infants undergoing cardiovascular surgery. We examined the effects of patient age, weight, and central venous pressure and the experience of the anesthesiologist on the rate of successful catheterization and catheterization time of the internal jugular vein (IJV) in a prospective study. We studied 106 infants undergoing IJV catheterization for cardiovascular surgery over a 7-mo period at our institution. We catheterized the IJV by the high approach. The direct venipuncture or the Seldinger method was used according to the patient's weight. Overall successful catheterization rate was 97.2%, and the average catheterization time was 353 +/- 21 s (mean +/- SEM). Complications included arterial puncture in 12 cases (11.3%), hematoma formation in four cases (3.8%), and catheter malposition in two cases (1.9%), but pneumothorax was not observed. When a patient was younger than 3 mo or weighed less than 4.0 kg, successful catheterization rate decreased significantly to 81.3% and 78.6%, respectively. Catheterization time was inversely correlated with both age and weight, whereas central venous pressure did not affect either successful catheterization rate or catheterization time. We were unable to demonstrate that the experience of the anesthesiologist plays a significant role in the success or complication of the catheterization procedure. Our results indicate that IJV catheterization by the high approach is a reliable and useful technique in infants, and that the weight and age of the patient significantly influence the rate of successful catheterization.

Age Factors

Toxicities of microencapsulated tribromomethane, dibromochloromethane and bromodichloromethane administered in the diet to Wistar rats for one month.

The gelatin-starch syrup microencapsulation method was applied to subacute toxicity studies of tribromomethane (TBM), dibromochloromethane (DBCM) and bromodichloromethane (BDCM). Groups of Wistar rats (7 males and 7 females) both sexes were given diet containing microcapsules of each of these trihalomethanes (THMs) at the following concentrations: TBM, 0.068, 0.204 and 0.612% in males, and 0.072, 0.217 and 0.651% in females; DBCM, 0.020, 0.062 and 0.185% in males, and 0.038, 0.113 and 0.338% in females; BDCM, 0.024, 0.072 and 0.215% in males, and 0.024, 0.076 and 0.227% in females. Suppression of body weight gain was seen in each high-dose males fed TBM or BDCM and females fed DBCM or BDCM. Histopathologically, hepatic lesions such as vacuolization and swelling of liver cells were significantly noted in both sexes of all groups fed TBM, in both sexes of the middle- and high-dose groups fed DBCM, and in males of the high-dose group and in females of the middle- and high-dose groups fed BDCM. In addition, single cell necroses were observed in males and females fed DBCM and in males fed BDCM. Hepatic cord abnormalities were also noted in males of the high-dose group fed BDCM. Although no increases in serum transaminase activities (ASAT, ALAT) were evident in either sex fed any of the THMs, decreases in triglyceride content, cholinesterase and lactate dehydrogenase activity were observed. Renal lesions reported to occur in gavage studies were not found in the present feeding study. Lowest-observed-adverse-effect-level (LOAEL) of TBM and no-observed-adverse-effect-level (NOAEL) of DBCM and BDCM were determined to be 56.4 mg/kg, 18.3 mg/kg and 20.6 mg/kg, respectively, under the present experimental conditions.

Administration, Oral

[A computerized anesthesia record system: four years' experience].

A computerized anesthesia record system is in routine use for cardiovascular procedures in our operating rooms. This system is implemented on an NEC PC-9801 personal computer and automatically collects hemodynamic variables from a polygraph as well as from intraoperative laboratory reports via RS-232C ports. Events such as intubation can be entered manually using a standard keyboard. Since the introduction of the system in 1987, the system has been used in 90 percent of the total cases performed and 2941 electronic data files were recorded in a four-year period. Excluding some short procedures for which the system was not used, failure to store records on disks resulted from system errors due to power-line troubles in the operating rooms as well as users' omission to command the system. User-acceptance of event entry was poor. In 74 percent of the cases, not a single event was entered. Advantage of an automated anesthesia record system over a hand-written record is being recognized. Wide-spread use of such a system will require ergonomic design of the system and man-machine interfaces suitable for use in an operating room.

Anesthesiology

[The change in cerebral blood flow during hypotensive anesthesia induced by prostaglandin E1].

We investigated the effect of prostaglandin E1 (PGE1)--induced hypotension during sevoflurane anesthesia on the cerebral blood flow (CBF), autoregulation and internal jugular venous O2 tension (PjO2) in 8 patients undergoing neurosurgery. Although the mean arterial pressure decreased from 95.3 +/- 3.8 mmHg (mean +/- SD) to 63.6 +/- 8.0 mmHg by continuous intravenous infusion of PGE1, CBF did not change significantly (97.2 +/- 10.6% of control value). During hypotensive anesthesia, autoregulation was well maintained in all patients, and the values of PjO2 did not suggest brain hypoxia at all. The results indicate that hypotensive anesthesia induced by PGE1 and sevoflurane is a safe and a reliable method for neuroanesthesia.

Adult

Anaesthetic management of phaeochromocytoma associated with tricuspid atresia.

The anaesthetic management of a patient with phaeochromocytoma, tricuspid atresia and pulmonary vascular stenosis is reported. The patient received no preoperative preparation with adrenergic blockers. Anaesthesia was induced and maintained with fentanyl, diazepam and sevoflurane. Intraoperative blood pressure was controlled with sodium nitroprusside, sevoflurane, phentolamine, and propranolol. For hypotension after resection of the tumour norepinephrine was required. This patient did not have a systemic to pulmonary shunt procedure performed, so the maintenance of pulmonary blood flow in the presence of haemodynamic instability during operation for phaeochromocytoma was a major concern. Monitoring of oxyhaemoglobin saturation (SpO2) with a pulse oximeter was considered to be useful because SpO2 may reflect pulmonary flow. During serious haemodynamic disturbances due to the manipulation of the tumour, the heart rate was inversely correlated with SpO2, but the relationship between mean arterial pressure and SpO2 was weak. Therefore, control of heart rate appeared to be more important than control of blood pressure in this case.

Adolescent

Chronic toxicity of 2,4,6-tri-tert-butylphenol in rats.

In order to study the chronic toxicity of 2, 4, 6-tri-tert-butylphenol (TTBP), groups of 40 Slc: Wistar rats of either sex were fed diet containing 0, 30, 100, 300 or 1000 ppm of TTBP for up to 24 months. Hematological, biochemical and histopathological examinations performed periodically revealed slight microcytic anemia, changes in some biochemical parameters relating to liver function and focal necrosis of liver cells following TTBP administration, and these changes observed in females were severer than those in males. No neoplastic responses following TTBP administration were noted. Noticeable changes were not observed in the 30 ppm group throughout the experimental period. Thus, it was concluded that TTBP causes liver injury characterized by focal necrosis with microcytic anemia and elevations of serum phospholipids and cholesterol levels presumably occurring as secondary effects following the liver injury.

Anemia

[A study on the usefulness of the OECD Combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test (ReproTox)].

We studied the usefulness of the OECD combined Repeat Dose and Reproductive/Developmental Toxicity Screening Test (ReproTox) using cyclophosphamide (CP), which is well known for its toxicological properties. CP was given daily by gavage to groups of 12 male and 12 female 8-week-old Sprague-Dawley rats at doses of 0, 2, 3, 4.5 or 6.7 mg/kg. Significant decreases in body weight and food consumption were observed in males given 6.7 mg/kg and in all treated females. One, 3 and 12 females died during pregnancy in the groups given 3, 4.5 and 6.7 mg/kg, respectively. In males 2 died in the 6.7 mg/kg group. Leukopenia and anemia were evident in treated males. The thymus and spleen weights were significantly decreased in treated rats. Histopathologically, atrophy of the thymus, spleen and bone marrow was observed. With respect to the reproductive/developmental toxicity, dose-dependent increases in postimplantation loss and postnatal death of pups were found in treated dams. The body weight of pups from treated dams was significantly lowered. Thus, most of the known toxicological properties of CP regarding systemic toxicity and reproductive/developmental toxicity were clearly demonstrated in this study. Therefore ReproTox can be considered a useful screening test for assessing repeat dose and reproductive/developmental toxicity of existing chemicals of high production volume, although teratogenic potential and adverse effects on spermatogenesis and fertility were not detected under the present experimental conditions.

Administration, Oral

[Leukocyte removability of a newly developed filter, RC-100, in rapid transfusion].

Leukocyte-depleted blood products are currently a burning issue in transfusion medicine. As methods for depleting leukocytes, the bedside filters are shown to have a high removal rate and several kinds of them are in use. We investigated the leukocytes removal rate of a new filter RC-100 (Pall Co., Glen Cove, NY) under the condition of rapid rate of transfusion during operations. In flow rates of 30, 60, 100 ml.min-1, the removal rate of leukocytes for CRC were 99.9 +/- 0.06, 100.0 +/- 0.00 and 99.4 +/- 0.20% respectively, and for WB 100.0 +/- 0.00, 99.9 +/- 0.10 and 99.1 +/- 0.70%, respectively. The recovery rates of erythrocytes were not significantly decreased for CRC and for WB in all flow rates. These results suggest that RC-100 could be useful either for CRC and for WB even with the rapid flow rate under 100 ml.min-1.

Blood Transfusion

[A case of early carcinoma of the remnant stomach that developed from gastritis cystica polyposa].

A 64-year-old man with an early carcinoma of the remnant stomach that developed from a gastritis cystica polyposa (GCP) is presented, and the morphology and histogenesis of this rare condition are discussed. This patient had a Billroth II reconstructed remnant stomach for 25 years, and was referred to our attention because of cholecystocholedocholithiasis. In screening an upper gastrointestinal barium study and an endoscopy revealed an irregular-shaped, flat, polypoid tumor in a stoma of the posterior wall. The resected polypoid lesion measured 4.5 x 3.0 cm. A histological examination revealed it to be a well differentiated adenocarcinoma of the mucosal layer that had developed from a GCP.

Adenocarcinoma

[Combined long-term toxicity/carcinogenicity test of alpha-bromocinnamic aldehyde (BCA) applied to female mouse skin].

Bromocinnamic aldehyde (BCA), an antibacterial/antifungal agent, was tested for its chronic toxicity/carcinogenicity in female Slc:ddY mice. The animals received 0.25%, 1.0% and 4.0% of BCA dissolved in olive oil applied to the shaved back skin area twice a week for 79 weeks. The control group received olive oil alone under similar conditions. In addition to these animals, 5 animals in each group were killed at 6 and 12 months for investigation of the time-related toxic effect of BCA. A slight inhibition of body weight increase and a slight decrease in the survival rate were seen in the 4.0% BCA-treated group. No significant changes were observed in hematological parameters at 6, 12 and 18 months. In chemical biochemistry determination in the blood at 6 and 12 months, a significant decrease in non-esterified fatty acid and phospholipid values was observed in the experimental groups. Histopathologically, necrosis, scabbing, cell infiltration and thickening of the epidermis were noted at the site of application in the 4.0% BCA group. Moreover, extramedullary hematopoiesis and amyloid degeneration were detected in the spleen, while the incidence of adenomas in the lung decreased with a dose-response. These changes seemed to be the result of a non-specific inflammatory reaction to the irritation effects of the agent on the skin. No significant differences in the incidence of tumors were found between the control and experimental groups, not only at the site of application but also in other organs, although lung adenomas decreased dose-dependently in all treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldehydes