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Biomedical subjects

M Nemoto

Publications and source records attributed to M Nemoto.

At least 91 records · Page 5Linked to original sources
PubMed1989

[Interaction between polyethylene films and bromhexine HCl in solid dosage forms. I. Effects of moisture contents in the solid dosage forms on the sorption of the drug].

The decrease of bromhexine HCl contents in granules and tablets was determined when the preparations were stored in polyethylene film package. Effects of temperature, contact area with film, excipients and moisture contents in the preparation on the remaining amount of bromhexin HCl were studied in order to investigate the interaction mechanism between bromhexine HCl and polyethylene film. It was observed that the decrease of bromhexine HCl was due to the sorption to the polyethylene film. The results indicated that the moisture contents of the dosage forms determined the rate of sorption predominantly, and that removal of adsorbed water from dosage forms was effective to prevent bromhexine HCl content decrease.

Adsorption↗
PubMed1987

[The effects of hyperoxemia on cerebral blood flow in subarachnoid hemorrhage patients].

The effects of oxygen inhalation at atmospheric pressure (1 ATA.O2) on CBF were studied in subarachnoid hemorrhage (SAH) patients due to ruptured intracranial aneurysms to prove the usefulness of the "O2 response" test for the evaluation of the cerebral vascular response. "O2 response" means the CBF (or ICP) decrease during hyperoxemia. CBF was measured by 10 m Ci 133Xe intravenous injection method using rCBF analyzer BI-1400 (Valmet). Two-compartmental analysis was used for the calculation of initial slope index (ISI). Studied cases were 53 postoperative SAH patients and 100 times examinations were done under the condition of Rest-1 ATA.O2. The incidence of global disturbance of the O2 response was 33% from day 0 to 3, 31% during day 4 to 7, 30% during day 8 to 14, and 23% at day 15 to 30. But, after day 31, there was no case which revealed an impaired O2 response. It was not possible to detect focal or hemispheric abnormalities of the O2 response because of the limitation of noninvasive two-dimensional CBF measurement method employed. The causes of O2 response abnormality, within a month after the onset, were increased ICP, hydrocephalus and diffuse brain damage. Multiple regression analysis proved that elevated PaO2 is the major factor in reducing CBF. CBF and ICP correlation study showed that the higher the Rest ICP, the fewer the CBF decreases during pure O2 inhalation. This may indicate that the increase in ICP in the acute stage changes the O2 response according to the level of increased ICP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Reproducibility of somatosensory evoked potentials and EEG in normal humans under hyperbaric oxygenation].

Hyperbaric oxygenation (HBO) was reported to have a favorable influence on ischemic brain dysfunction, and also appeared to be useful in improving brain edema. Somatosensory evoked potentials (SEP) and EEG would be available as indicators of brain function. The purpose of this paper is to study reproducibility of the N1-amplitude of SEP and EEG under HBO. Materials were 10 normal volunteers, from 21 to 31 (mean age: 26) years old. Two stimulating needle electrodes were inserted into the skin at the wrist and somatosensory stimulations were applied to the median nerve with 1 msec duration square pulses. Stimulation pulses were generated regularly every 1 sec., and stimulus intensity was adjusted just above the thumb twitch threshold. Monopolar EEGs were recorded from 16 silver-cup electrodes on the scalp, and SEPs were recorded by averaging 250 responses in those EEGs using computer technique. N1-amplitude was determined by the vertical distance between peaks of the P1 and N1 components. EEGs were analyzed by Fast Fourier Transform and the square root of the averaged power of each frequency band (delta, theta, alpha 1, alpha 2, beta) was obtained and evaluated as the equivalent potential. EEGs under the influence of sleeping or artifacts, such as electromyograms, eye lid movements and wandering of the base line, were excluded in evaluating the EEGs. SEPs and EEGs recorded consecutively. The first record was taken before HBO under air breathing at 1ATA, the second during HBO under pure oxygen breathing at 2ATA, and the third after HBO under air breathing at 1ATA once again.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

[Effects of hyperoxia, glycerol and ventricular drainage on ICP and CBF in patients with increased ICP due to CSF circulatory-absorbance disturbance].

The effects of hyperoxia, glycerol and ventricular drainage on intracranial pressure (ICP) and cerebral blood flow (CBF) were studied in cases with cerebrospinal fluid (CSF) circulatory-absorbance disturbance due to subarachnoid hemorrhage (SAH) or intraventricular hematoma. Ventricular fluid pressure (VFP) was monitored through a controlled ventricular drainage (CVD) tube using a Statham P-50 pressure transducer. CBF was measured by the 10mCi133Xe intravenous injection method using a Valmet BI-1400 rCBF analyzer. ISI (initial slope index) was used for the CBF value. Studied cases were 19 SAH patients and 2 hypertensive intracerebral hematoma cases with intraventricular hematoma. Hyperoxia included hyperbaric oxygen (HBO), reduced ICP and CBF. During pure oxygen inhalation at atmospheric pressure (1ATA . O2), there was a tendency toward a relationship showing that the higher the resting state ICP, the lesser the likelihood of a CBF decrease. This may indicate that increased ICP impairs cerebral vascular reactivity to hyperoxia in relation to the degree of elevation. The effects of hyperoxia on ICP and CBF were temporary and they promptly returned to the resting state after cessation of oxygen inhalation. In some cases, there was a rebound phenomenon in ICP after HBO. Glycerol administration reduced ICP and increased CBF. There was no clear correlation between resting state ICP and CBF increase after glycerol administration. The effects of glycerol were also temporary. ICP control by opening CVD increased CBF. There was a correlation between the level of resting state ICP and the CBF increase after the opening of CVD. In cases with CSF circulatory-absorbance disturbance, elevated ICP reduced CBF and may further worsen the cerebral damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Antishock effects of corticosterone on dextran-induced shock in rats.

To study the effects of glucocorticoid on the shock state, dextran-induced shock in rats was used as an experimental model system. The rats were divided into three groups, viz., control (group A), adrenalectomized (group B), and adrenalectomized corticosterone supplemented (2 mg/rat for 4 days; group C), and 5% dextran solution was given intravenously to each rat. In group B, remarkable increases in the histamine levels in both plasma and the paw cutaneous tissue, hemoconcentration, and intractable hypotension were observed. Most rats in group B died during the shock experiment without showing any recovery when the cannulas were inserted into the left carotid artery for the measurement of blood pressure. But in group C, most rats eventually survived and recovered to a normal state within 2 h, so that corticosterone clearly ameliorated the shock state of adrenalectomized rats by dextran administration. These results suggested that the ameliorating effects of corticosterone in the dextran-induced shock states are due to the acceleration of the rate of clearance of circulating chemical mediators that are represented by histamine and are due to the alteration of overall responsiveness of the animals to a complex array of factors that threaten the status of the animals, as represented by the amelioration of the vascular activity.

Adrenalectomy↗
PubMed1986

Delayed inactivation of Citrobacter freundii cephalosporinase by 6 beta-[3-(2-chlorophenyl)-5-methyl-4-isoxazolyl]penicillin sulfone.

When Citrobacter freundii cephalosporinase was incubated with 6 beta-[3-(2-chlorophenyl)-5-methyl-4-isoxazolyl]penicillin sulfone (cloxacillin sulfone) in phosphate buffer, the enzyme was suddenly inactivated just after the completion of enzymatic degradation of the cloxacillin sulfone. Such delayed inactivation was due to a secondary inhibitor formed from cloxacillin sulfone during the incubation period. The inactivation was delayed due to the protection of the enzyme by cloxacillin sulfone from the attack of the secondary inhibitor. Phosphate anions were essential for the formation of the secondary inhibitor. However, once the secondary inhibitor was formed, the inactivation occurred in the absence of phosphate anions although the degree of the inactivation depended on the length of the preincubation period with phosphate anions. The main species (more than 80%) of the inactivated enzyme was detected as a single protein band with a slightly lower pI value than that of the native enzyme on isoelectric focusing on a plate.

Buffers↗
PubMed1986

[A case of pineocytoma presenting with symptoms like normal pressure hydrocephalus].

A pineocytoma in an old man, whose initial symptoms resembled a normal pressure hydrocephalus, is reported. This 67-year-old man gradually became uncommunicative and difficult to walk alone in three months. Just before visiting our clinic, his family also noticed his nocturnal urinary incontinence. CT scan on admission disclosed tumor in the posterior wall of the third ventricle, and subsequent hydrocephalus. This oval, isodense tumor was homogeneously enhanced after the injection of contrast medium on CT scan. The vertebral angiography showed a mass in the pineal region with no vascular staining. Ventricular drainage, the opening pressure of which was 100 mmH2O, could not offer cytological verification of the tumor. By the infratentorial supracerebellar approach, the tumor was successfully extirpated, and the post-operative course was uneventful. The microscopic study revealed the nature of this tumor to be well compatible with that of a pineocytoma.

Aged↗