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Biomedical subjects

M Hashiba

Publications and source records attributed to M Hashiba.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Modification of the cytotoxic effect of peplomycin by cepharanthine].

The cytotoxicity of peplomycin modified by cepharanthine, was studied on in vitro cultured Chinese Hamster V-79 cells. Cepharanthine alone showed almost no cytotoxicity on this tumor system. It was revealed that cepharanthine enhanced the cell killing action of peplomycin and also promoted the recovering process from the effects of peplomycin. The enhancing effect increased with an increase of the concentration at the lower concentrations but there were limitations at the higher concentrations. The bi-phasic properties specific to peplomycin on the dose-survival curves were unchanged even in combination with cepharanthine was observed in the recovering process from the effects of peplomycin. From these results, cepharanthine seemed not to affect on the mechanism of action of peplomycin.

Alkaloids↗
PubMed1986

Radiation therapy for nasopharyngeal carcinoma. Retrospective review of 105 patients based on a survey of Kansai Cancer Therapist Group.

One hundred five patients with nasopharyngeal carcinoma were treated with radiation therapy combined with or without chemotherapy at 16 of the participating institutes in Kansai Cancer Therapist Group, Japan, from January 1978 to December 1980. The study comprised 77 males and 28 females; their ages ranged from 15 to 80 years (mean, 53 years). Five-year survival rates according to stage were as follows: Stage I, 100%; Stage II, 67%; Stage III, 44%; and Stage IV, 34%. As far as Stage IV disease was concerned, the radiation therapy only group showed significantly poorer prognosis than the combined radiation and chemotherapy group (P less than 0.05). Concerning the N stage and treatment method, the radiation therapy only group showed a higher metastatic rate than the chemotherapy combined group (35% versus 14%, P less than 0.05).

Adolescent↗
PubMed1984

Anesthetics and excitatory/inhibitory responses of midbrain reticular neurons.

The effects of nitrous oxide, halothane, ether, isoflurane, thiopental, and thiamylal on the excitatory as well as inhibitory responses of single neurons in the midbrain reticular formation (MRF), believed to be one of the most important sites for the regulation of wakefulness, were studied by long-term, extracellular microelectrode recording in cats and rats. All anesthetics except nitrous oxide suppressed the excitatory responses of MRF neurons evoked by somatosensory stimulation. The inhibitory responses markedly were potentiated by both barbiturates but variously affected by other inhalation anesthetics. Blockade of the inhibitory responses (disinhibition) was observed more frequently with the inhalation agents during the light state of anesthesia. Thus, suppression of excitatory responses is likely to be a general feature of the anesthetic state in terms of the behavior of MRF neurons. Further, potentiation of the inhibitory responses might be characteristic of barbiturate anesthesia.

Anesthetics↗
PubMed1983

Cerebral cortical extracellular fluid H+ and K+ activities during hypotension in cats.

Cerebral cortical blood flow, electrical activity, and extracellular fluid (ECF) pH and K+ ion activities were measured in anesthetized cats (0.7% halothane 65% N2O in O2) subjected to hypotension (mean BP 30-32 and 26-28 mmHg), induced by either practolol and trimetaphan (TMP) or practolol and nitroprusside (NTP). Limited blood withdrawal was also necessary to achieve these blood pressure (BP) levels. Cerebral cortical blood flow during hypotension was greater with NTP than with TMP, and hyperemia occurred in the recovery phase after NTP but not TMP. Electrical activity also was maintained better with NTP. ECF K+ increased in five of six TMP experiments but in only one of six NTP experiments. Values of K+ greater than 15 mM were only seen in the TMP group. Release of K+ into the ECF space occurred at values of cerebral cortical oxygen delivery below 3 ml 100 g-1 min-1. ECF K+ partially recovered after the end of hypotension in all except the experiment with the highest value. A progressive and severe cerebral acidosis was seen in all experiments during induced hypotension, and values below pH 6.50 were present at the stage of K+ increase in the ECF space. It is concluded that the ability of cell membranes in the cat's cortex to maintain normal ionic gradients is depressed by hypotension to these levels with TMP, but not with NTP, and that this difference is related to better-maintained oxygen supply values during NTP hypotension.

Animals↗
PubMed1983

[Therapeutic evaluation of an ampicillin suppository (KS-R1) used against acute suppurative otitis media in children: a comparison with an oral preparation].

A comparative well-controlled study was performed to evaluate the efficacy and tolerability of KS-R1 (ampicillin rectal suppository, 125 mg X 4/day) administered to the rectum as compared with those of orally administered ampicillin (ABPC) with same dosage. The results obtained were as follows. The clinical effect of the drug was judged in 100 cases (suppository group in 45 cases, oral group in 55 cases) out of 111 cases. The overall efficacy rates evaluated on standard criteria were 93.3% for the suppository group and 89.1% for the oral group. There was no statistically significant difference between 2 groups. Evaluation by stratification according to the dose, disease type and age also revealed a slightly higher efficacy rate on each parameter in the suppository group, but no significant difference between 2 groups. The bacteriological effects evaluated in 84 cases (suppository group in 38 cases, oral group in 46 cases) were 94.7% and 93.5%, respectively. There was no statistically significant difference between 2 groups. Side effects were evaluated in 101 cases (suppository group in 46 cases, oral group in 55 cases), but the incidence rate showed no significant difference between the 2 groups; 3 cases (each 1 of abdominal pain, periproctal redness and periproctal erosion) were observed in suppository group and 2 cases (each 1 of stomach pain + soft stool and diarrhea) in oral group. The results indicate that KS-R1 is equally effective and tolerable against acute suppurative otitis media compared to oral administration of ABPC, and considered to be useful.

Administration, Oral↗
PubMedDate not supplied

Determination of 1,5-anhydroglucitol in urine by high performance liquid chromatography and an enzyme sensor.

A simple high performance liquid chromatographic method combined with an enzyme sensor has been developed to measure 1,5-anhydroglucitol in urine. The enzyme sensor consists of a hydrogen peroxide electrode and a chitosan membrane of an immobilized pyranose oxidase. As the system does not resist interfering substances, urine samples are first purified by passing them through a two-layer column packed with (1) strongly basic anion (OH- form, the upper layer) and (2) strongly acidic cation (H+ form, the lower layer) exchange resins. 1,5-Anhydroglucitol is efficiently recovered in the flow-through fraction of the column. In this system, the minimum detectable concentration of 1,5-anhydroglucitol is 0.1 mg/L, and the measurable range extends from 0.1 to 60 mg/L. The coefficient of variation values of the within-day and day-to-day precisions are 3.0-6.5% and and 4.4-6.7% respectively, and there is good agreement between the results measured by our method and those obtained by the gas-liquid chromatographic/mass spectrometric method (r = 0.994). The method we have described here has been successfully used to elucidate a mechanism for the reducing 1,5-anhydroglucitol level in the serum and plasma of patients.

Biosensing Techniques↗
PubMedDate not supplied

Does the endolymph pass through the base of the cupula?

Whether the endolymph of the semicircular canal passes the cupular partition or not was examined using the lateral semicircular canal system of adult pigeons (Columba livia). By applying various pressures by means of injection of a dye solution through the membranous canal, it was found that the dye solution, was seen to pass the cupula even under very low pressures when the pressure was increased gradually. When pulled by a magnet, the ultrafine particles of the dextran magnetite contained in the injected fluid were found to pass through the subcupular space without evident increase of the ampullary pressure.

Animals↗
PubMedDate not supplied

Application of the RealAudio package to computerized medical lectures.

We created a multimedia system to computerize past lectures using RealAudio software. Physicians, medical researchers and students can browse the contents of lecture slides and handouts with synchronous audio using the Internet. The audience can easily review the most interesting parts of lectures and medical students can listen to complete medical lectures from remote sites with narration and slide depiction, whenever convenient. We have created three multimedia programs; the memorial lecture of a professor's retirement, a new method of hand washing for surgical procedures and a lecture on medical informatics. The cost of this system and the results of the evaluation by medical students are described. The ease of using this application makes it a potentially valuable tool for clinicians and researchers.

Computer-Assisted Instruction↗
PubMedDate not supplied

Production of cyclic nucleotides from normal human brain.

Concentrations of cyclic AMP and cyclic GMP in arterial and internal jugular venous (IJV) blood were determined at the resting wakeful state in thirty surgical patients without neurological deficits. The levels of cyclic AMP in artery and IJV were 32.1 +/- 3.0 and 40.0 +/- 4.1 pmol/ml (means +/- standard errors), respectively, while those of cyclic GMP in artery and IJV were 12.2 +/- 2.7 and 14.4 +/- 3.0 pmol/ml, respectively. Concentrations of both cyclic nucleotides in IJV were significantly higher (P less than 0.001) than those in artery. IJV-arterial differences for cAMP and cGMP were 7.9 +/- 1.7 and 2.1 +/- 0.5 pmol/ml, respectively. The results indicate that both cyclic nucleotides are constantly produced and released from the normal human brain.

Adolescent↗
PubMedDate not supplied

The effects of extreme hemodilutions on the autoregulation of cerebral blood flow, electroencephalogram and cerebral metabolic rate of oxygen in the dog.

The effects of profound (hematocrit value, Ht 20%) and extreme (Ht 5%) hemodilutions on the relationship between the mean arterial pressure (MAP) and the cerebral blood flow (CBF) were studied in pentobarbital-anesthetized dogs. A regression line was found between the CBF and Ht values during normotensive hemodilution (MAP 100 torr): CBF (ml/100g X min) = -98.9 log Ht (%) + 195.5 (p less than 0.001). The CBF was increased by hemodilution, but the range of its autoregulation was narrowed, suggesting a progressive susceptibility of CBF to blood pressure with hemodilution. The electroencephalogram (EEG) was not significantly changed by hemodilution within the range of the CBF autoregulation, below which it became slowed. In contrast, the cerebral metabolic rate of oxygen (CMRo2) was decreased by hemodilution even within the range of the CBF autoregulation, while there were no significant differences in CMRo2 values between MAPs of 100 and 40 torr. Thus, the brain function in terms of the EEG seemed to correlate more with the autoregulatory mechanism of the CBF than with the CMRo2 value in the hemodiluted states.

Animals↗