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Biomedical subjects

J Kotani

Publications and source records attributed to J Kotani.

At least 19 recordsLinked to original sources
PubMed1992

Effects of bilateral jugular vein ligation on intracranial pressure and cerebrospinal fluid outflow resistance in cats.

In order to study the effect of jugular venous outflow obstruction on intracranial pressure and cerebrospinal fluid (CSF) reabsorption capability, changes in epidural pressure (EDP) and CSF outflow resistance (Ro) were examined following bilateral jugular vein ligation in cats. EDP increased significantly (P less than 0.01) immediately after ligation from the control value of 4.9 +/- 0.5 mmHg (mean +/- SEM) to 15.9 +/- 0.9 mmHg. Thereafter, EDP gradually decreased back toward the control value. The pressure level had decreased to 6.7 +/- 0.5 mmHg by 20 minutes after ligation. The mean Ro was significantly (P less than 0.01) higher in the ligation group (200.4 +/- 9.7 mmHg/ml/min) that in the non-ligation group (120.0 +/- 9.9 mmHg/ml/min). These results suggest that bilateral jugular vein ligation impairs CSF reabsorption.

Absorption↗
PubMed1992

Re-evaluation of death by asphyxia based on cerebral blood flow (VII)--on the information on electric potentials obtained from deep electroencephalographic electrodes.

The author presents electroencephalographic patterns (a physiological parameter of the brain function observed at rapid and fatal drowning of rabbits), cerebral blood flow (CBF) which support the physiological activities of the brain, and the relationship between systemic respiration and circulation with special reference to changes in the electrical potentials detected by deep electroencephalographic electrodes. The possibility of diagnosis of fatal drowning is examined, based on the results.

Action Potentials↗
PubMed1992

[Mathematical simulation of intracranial condition--Part 1. Linear model stimulation].

We developed a linear mathematical model of the intracranial vessels, which reflects changes of the pulse wave (pulse pressure) of intracranial pressure after ligation of the internal jugular vein. The model composed of eight major variables: 1. resistance of arteries, 2. resistance of small arteries and capillary vessels, 3. resistance of veins, 4. resistance of internal jugular and vertebral veins, 5. compliance of arteries, 6. compliance of small arteries and capillary vessels, 7. compliance of veins and 8. intracranial compliance. All variables are presumed to have linear elements and replaced with electrical elements. The model of neck dissection is expressed as the change of resistance of the internal jugular and vertebral veins. Intracranial condition is expressed as the pulse wave (pulse pressure) of intracranial pressure and driving pressure. After unilateral ligation of the internal jugular vein, the pulse wave of intracranial pressure increased 24% and, after bilateral ligation of the internal jugular vein, it increased 55%. After unilateral ligation of the internal jugular vein, the pulse wave of intracranial pressure increased 27%, and, after bilateral ligation, it increased 79%. When intracranial compliance is normal, the respective ratios of pulse wave of intracranial pressure and driving pressure to cross-sectional area decreased, whereas those after increase of intracranial compliance increased.

Cerebrovascular Circulation↗
PubMed1991

[Influence of location for jugular venous blood sampling to cerebral circulatory index (CCI)].

When cerebral circulatory index (CCI) expressed as inverse of arterial-jugular venous oxygen content difference is measured, venous sampling at the internal jugular bulb needs to be done in order to avoid mixture with extra-cerebral perfusion blood. To estimate the validity of this point, difference of values calculated with blood obtained simultaneously at the jugular superior bulb, the inferior region and the cerebral sinus were examined in monkeys. As a result, no significant differences were found to result from location of the sampling, and significant correlation between PaCO2 and CCI was recognized. These findings supported the idea that CCI reflects the cerebral blood flow due to PaCO2 changes.

Animals↗
PubMed1990

Cerebral blood flow and serum haptoglobin in the diagnosis of death by rapid drowning.

Diagnosis of death and the feasibility of resuscitation in cases of acute drowning in fresh water (FW) or sea water (SW) inhalation in rabbits were evaluated using cardiopulmonary function monitoring, measurement of cerebral blood flow (CBF) and determination of haptoglobin (HP). Death took place more quickly in FW drowning, two to five minutes, as compared with four to seven minutes required in SW drowning. In view of the CBF patterns in the brain circulation, many problems exist regarding the judgement of the point of death and the applicability of resuscitation. However, it is considered that brain damage in SW drowning occurs more rapidly than in FW drowning.

Animals↗
PubMed1990

[Changes in the intracranial pressure dynamics with head-down tilt in cats].

To determine changes in the intracranial pressure dynamics under the condition of head-down tilt, the pressure-volume relationship in the cranial cavity as well as changes in intracranial pressure were studied experimentally in 31 cats. The animals were divided into three groups; with the horizontal, with the head-down and one with the head-up position. In each group the pressure volume index (PVI) and cranial cavity compliance (C) were examined under controlled respiration. The following results were obtained. (1) The values of PVI and C were significantly greater in the head-down tilt group as compared to those in the other groups, in spite of the increase in intracranial pressure level. (2) In the situations of craniospinal blockade by epidural ligation of spinal cord at C2 level, the PVI and C were also higher in the head-down tilt group than in the horizontal group. These results indicate that the pressure buffering capacity is increased with head-down tilt with respect to intracranial volume loading. It appears that the buffering mechanism does not depend on movement of the cerebrospinal fluid, but on the increased cerebral venous vascular bed with the communication between extracranium and intracranium.

Animals↗
PubMed1983

Effect of internal jugular vein ligation on resorption of cerebrospinal fluid.

The influence of jugular vein ligation on CSF resorption was examined experimentally by means of a manometric ventricular infusion test in dogs. Capacity of CSF absorption was decreased in a stepwise manner according to whether unilateral or bilateral ligation of jugular veins was performed. Interestingly, in addition to rises in ICP, dural sinus pressure was predominantly elevated after bilateral jugular ligation, often exceeding the ICP level. The CSF malresorption observed was considered to be closely related to the lowered pressure gradients between ICP and intracranial sinus pressure.

Animals↗
PubMed1982

[Basic and clinical evaluations of cefmetazole in postoperative wound infections].

The time course of the concentration of cefmetazole (CMZ) in the serum and in skin and intestinal tissues was determined after a single intravenous injection of 2 g of the drug. CMZ moved into them well. Furthermore, 41 patients with postoperative wound infection (superficial in 29 and deep in 12) were treated with CMZ 2-4 g daily. Bacteriological examination of the lesions with simultaneously carried out. As a result, 101 strains of bacteria were isolated and identified. Mixed infection was found in 27 cases (65.9%). Fifteen strains (14.9%) of E. coli, 15 (14.9%) of B. fragilis, 7 (6.9%) of Klebsiella sp. and 7 (6.9%) of Proteus sp., were the main bacteria isolated. Eight cases (19.5%) had mixed infection of E. coli and B. fragilis. The committee (3 members) evaluated CMZ to be effective in 75.6% (31 of 41 cases) and bacteria disappeared in 60.5% (23 of 38 cases). The side effects observed were pyrosis and feeling of gastric malaise in 1 case. The results suggest that CMZ is useful, which exerts an excellent effect on postoperative wound infections.

Adolescent↗