PubMed Health⌕ Search

Biomedical subjects

T Niitsu

Publications and source records attributed to T Niitsu.

10 recordsLinked to original sources
PubMed2000

Intubating laryngeal mask for fibreoptic intubation--particularly useful during neck stabilization.

PURPOSE: To assess the ease of fibrescope-assisted tracheal intubation while the patient's head and neck were placed in the neutral or the manual in-line position, and to determine if the intubating laryngeal mask facilitated fibreoptic intubation in these positions. METHODS: In 84 patients, the patient's head and neck were placed in the neutral position (pillow placed under occiput), and in another 40 patients the head and neck were stabilized by the manual in-line method (no pillows under occiput). In both groups, after induction of anesthesia with 2.0-2.5 mgxkg(-1) propofol, 50-100 microg fentanyl and 1.0 mgxkg(-1) vecuronium, patients were allocated randomly into two groups: in Group C tracheal intubation was attempted using only a fibrescope, whereas in Group L fibreoptic intubation through the intubating laryngeal mask was attempted. RESULTS: In group C the success rate of fibreoptic tracheal intubation within two minutes was higher in the neutral position (31 of 42 patients (73%)) than in the manual in-line position (8 of 20 patients (40%)). In contrast, in group L the success rate was similar between the two positions. Tracheal intubation was easier in group L than in group C (P < 0.01 or 0.001) and the time for intubation was shorter in group L than in group C in both head and neck positions. CONCLUSIONS: Fibreoptic tracheal intubation was more difficult in the manual in-line position than in the neutral position. The intubating laryngeal mask facilitated fibreoptic intubation in both positions.

Anesthesia, Inhalation↗
PubMed1996

Changes in the cerebral arteriovenous oxygen content difference by surgical incision are similar during sevoflurane and isoflurane anaesthesia.

PURPOSE: To investigate changes of cerebral arteriovenous oxygen content difference (AVDO2) induced by surgical incision and to determine carbon dioxide (CO2) reactivity of the cerebral circulation during sevoflurane and isoflurane anaesthesia. METHODS: Twenty-one ASA 1-2 patients undergoing elective surgery for supratentorial tumours were randomly allocated to receive either 1.3 MAC sevoflurane/N2O anaesthesia (n = 10) or equi-MAC isoflurane/N2O anaesthesia (n = 11). Before and after incision, haemodynamic measurements and AVDO2 determinations were performed. After opening the dura, AVDO2 was determined before and after the respiration rate was increased by 50%. RESULTS: Incision produced an increase in mean arterial pressure from 69 +/- 11 to 97 +/- 22 mmHg (mean +/- SD) (P < 0.0005) and from 71 +/- 6 to 89 +/- 12 mmHg (P < 0.0001) in the sevoflurane and isoflurane groups, respectively, whereas the heart rate increased from 60 +/- 9 to 72 +/- 8 bpm (P < 0.001) and from 65 +/- 6 to 70 +/- 7 bpm (P < 0.001), respectively. Arterial carbon dioxide tension (PaCO2) was increased from 33.6 +/- 2.3 to 34.6 +/- 1.8 mmHg (P < 0.05) with incision in the sevoflurane group. The AVDO2 was decreased from 6.5 +/- 1.6 to 5.3 +/- 1.6 vol% (P < 0.0005) in the sevoflurane group and from 6.7 +/- 1.1 to 6.0 +/- 1.1 vol% (P < 0.01) in the isoflurane group. The % change of AVDO2 was larger in the sevoflurane group than in the isoflurane group (-18.3 +/- 8.4% vs -9.1 +/- 9.0%; P < 0.05) but no difference remained after the post-incisional AVDO2 value of the sevoflurane group was corrected for pre-incisional PaCO2. Carbon dioxide reactivity, calculated as the percent change in AVDO2 per mmHg change in PaCO2, was 6.1 +/- 3.0%.mmHg-1 in the sevoflurane group and 5.9 +/- 2.4%.mmHg-1 in the isoflurane group (P = NS). CONCLUSIONS: Sevoflurane and isoflurane are associated with similar impairment of cerebral flow-metabolism coupling at incision, while CO2 reactivity is maintained during both anaesthetics.

Adult↗
PubMed1994

Point mutation of aldehyde dehydrogenase-2 gene in mutant strains of Long-Evans rats.

Long-Evans Cinnamon (LEC) and Long-Evans Agouti (LEA) rats are mutant strains established from Long-Evans rats. LEC rats display hereditary hepatitis and spontaneous hepatocellular carcinoma, but LEA rats do not develop liver diseases. We previously demonstrated that LEC rats had an impairment of liver aldehyde dehydrogenase (ALDH) activities, and all LEC rats which were fed with a liquid diet containing 5% ethanol died within 2 weeks. In the present study, we also found that LEA rats could not metabolize ethanol and died after being fed the same diet. Remarkably, in the liver of LEA rats, low Km ALDH activities were suppressed as much as in LEC rats. These results suggested that both LEC and LEA rats have hereditary deficiencies in ALDH. Nucleotide sequence analysis of ALDH2 genes in both LEC and LEA rats demonstrated that the point mutation of the codon for residue 67 encoding Gln to Asp was observed; this was not so in either Long-Evans rats or Wistar rats. This mutation in ALDH2 genes may cause inactivation of ALDR activity in LEC and LEA rats.

Aldehyde Dehydrogenase↗
PubMed1991

[ECG changes associated with PGF2 alpha injection into the basal cistern of rabbits].

In the previous studies by the authors, it was shown that various types of changes in electrocardiograph were produced by injection of a small dose of PGF2 alpha into the basal cistern of rabbits which were studied to examine the mechanisms of those in humans with subarachnoid bleeding. In this study with reference to elucidating nerve pathways of PGF2 alpha produced stimulation, changes in electrocardiograph were examined in three groups of the animals which underwent dissection of the spinal cord either at C2-3, or at Th7-8, or bindings of bilateral suprarenal artery and vein, prior to the administration of PGF2 alpha into the basal cistern. The administration of PGF2 alpha decreased more significantly appearance rate of electrocardiographic alterations in the animals following spinal cord dissection at C2-3, and bindings of the suprarenal vessels than the animals with spinal cord dissection at Th7-8. It was concluded that the development of these electrocardiographic abnormalities was caused by direct autonomic discharges to the heart as well as by increased circulating catecholamines.

Animals↗
PubMed1989

Model of electrocardiographic changes seen with subarachnoid hemorrhage in rabbits.

We developed a new method for introducing drugs into the basal cistern of rabbits. With minimal surgical invasion, we used either the opening of the craniopharyngeal duct to access the chiasmatic cistern or the suture between the basisphenoid and basioccipital bones to access the interpeduncular cistern. With our method, 0.5 ml contrast medium injected into three rabbits was determined roentgenographically to remain in the basal cistern; histologically, all the brain tissue remained intact. Intracisternal injection of 0.5 ml physiological saline into five rabbits had no effect on the cardiovascular system. In 23 rabbits, injection of 0.5 ml 0.1% prostaglandin F2 alpha led to a variety of electrocardiographic changes, including sinus bradycardia (in 43.5%), premature atrial contractions (in 17.4%), and premature ventricular contractions (in 39.1%). In 15 rabbits with severe changes, arrhythmia was followed by ST depression (in 30.4%), ST elevation (in 8.7%), T wave inversion (in 4.3%), ventricular tachycardia (in 17.4%), or ventricular fibrillation (in 4.3%). Intracisternal injection of 0.5 ml 1.0% lidocaine into the 23 rabbits was very effective in overcoming bradycardia and arrhythmias. We conclude that the clinical features of electrocardiographic changes seen in patients with subarachnoid hemorrhage are reproducible in this rabbit model.

Animals↗
PubMed1989

Antioxidant enzyme status and lipid peroxidation in various tissues of diabetic and starved rats.

The effect of short term (2-wk) diabetes induced by streptozotocin and starvation (1-wk) on antioxidant enzymes and lipid peroxidation in the liver, kidney and heart of rats was investigated. The activity of mitochondrial oxidative markers was increased in diabetic liver and kidney, while the activity in tissues of starved rats tended to be decreased. Immunoreactive manganese superoxide dismutase was increased only in diabetic liver and was unchanged or decreased in the rest of the tissues. Glutathione peroxidase activity was increased in tissues of diabetic but not starved rats. The changes in copper-zinc superoxide dismutase and catalase in diabetic rats were similar to those in starved rats. In both groups, copper-zinc superoxide dismutase was decreased in liver, while catalase activity was decreased in liver and kidney, and increased in heart. The lipid peroxide level was increased in diabetic kidney and in the heart of starved rats, and decreased in the rest of the tissues. Insulin treatment in diabetic rats and refeeding in starved rats restored most of the abnormalities toward normal. These results suggest that accelerated mitochondrial oxidative metabolism not accompanied by induction of manganes superoxide dismutase results in oxidative injury in the hypertrophied kidney at an early stage of diabetes and possibly contributes to the development of nephropathy. Peroxidative myocardial damage in starved rat appears to be mediated by a catabolic process.

Animals↗
PubMed1989

[Anesthetic management in surgery of thoracic aortic aneurysms--a report of eleven cases].

Anesthetic management of patients with thoracic aneurysm is discussed. During a period of two years, 11 cases were observed; 7 cases of dissecting aneurysm and 4 cases of true aneurysm. Dissecting aneurysms were of DeBakey's type 1 in 5 cases and of DeBakey's type 2 in 2 cases. Four cases had hypertension. As many of these patients often have hypertension, it is important not to change the circulatory dynamics during induction of anesthesia. We employed high dose fentanyl in 9 cases and used nitroglycerin or nitroprusside to control systolic blood pressure at about 100-120 mmHg. Massive bleeding can occur during intraoperative period and it is important to secure a sufficient number of intravenous routes to protect the central nervous system during cardio-pulmonary bypass.

Aged↗