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Biomedical subjects

M Furuta

Publications and source records attributed to M Furuta.

At least 19 recordsLinked to original sources
PubMed1992

Sex-linked recessive lethal test of Drosophila melanogaster after exposure to 50-Hz magnetic fields.

To determine whether a 50-Hz magnetic field will induce mutations, a sex-linked recessive lethal test of Drosophila melanogaster was performed. Adult flies were exposed at an rms flux density of 500 mu T or 5 mT to the homogeneous field of a Helmholtz coil. The ambient field to which controls were exposed was less than 1 mu T. Exposures took place continuously for 13 to 14 days, which correspond to the life cycle of Drosophila at 25 degrees C. About 10,000 X-chromosomes were tested at each flux density. Recessive lethal mutation rates of 0.13, 0.21, and 0.18 percent were observed, respectively, for control, 500-mu T, and 5-mT conditions. By the Kastenbaum-Bowman significance test, the recessive lethal mutation rates in the 500-mu T and 5-mT conditions did not differ from the mutation rate of controls.

Animals↗
PubMed1992

Acute effects of tobacco smoking on the autonomic nervous system in comparison with alcohol drinking.

A total of 21 male university students were used to investigate the acute physical effects on the autonomic nervous system of two adult daily habits; smoking and drinking. A tobacco loading trial and an alcohol loading trial were conducted, keeping the conditions as uniform as possible. The nine subjects were instructed to smoke two cigarettes in 10 minutes, and their blood pressure, heart rate, and pupil diameter were measured. In addition, blood samples were taken 30 minutes after initiation of the trial, and the level of nicotine in the samples was measured (Trial 1). The twelve subjects were instructed to drink one large bottle of beer in 10 minutes, and the same parameters were measured. (Trial 2: trial for comparison). The pupil diameter decreased significantly 30 minutes after the subjects started smoking. Also, the heart rate increased suddenly as soon as the subjects started smoking, and the increase in the heart rate was pronounced for the 10 minutes that they were smoking. The maximal and minimal blood pressures generally did not fluctuate greatly. On the other hand, the pupil diameter tended to decrease slightly as soon as the subjects began drinking, and no significant difference in this value was noted. Also, even though the heart rate tended to increase slightly, no significant difference was noted in this value. In contrast, the maximal blood pressure increased significantly when the subjects started drinking, and tended to decrease gradually after they finished drinking.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Analysis of factors related to hypertension in Japanese middle-aged male workers.

A total of 789 Japanese male transport service workers between the ages of 35 and 50 were used as subjects in an analysis of daily lifestyle factors related to hypertension. Multiple logistic analysis showed positive dose-response relations between hypertension and age, obesity and alcohol consumption. Age and obesity were factors having a linearly increasing odds ratios for hypertension (including borderline cases and those under treatment). Alcohol consumption of 56 g ethyl alcohol per day or more had an odds ratio about double that of those who did not drink. Smokers had 1/2 the odds ratio of non-smokers. Subjects working a 24-hr shift comprised mostly of standby duty showed a slightly lower rate of hypertension, but it was statistically insignificant.

Adult↗
PubMed1991

Circulatory disturbances of the foot in vibration syndrome.

Circulatory disturbances of the foot in patients with vibration syndrome were studied by measuring the skin temperature of both index fingers and great toes through a 3-min immersion of the right foot in cold water at 10 degrees C. Subjects included 11 patients with vibration-induced white finger (VWF) [VWF(+) group], 12 patients without VWF [VWF(-) group], and 20 healthy referents not exposed to vibration. Patients were all male chain saw operators who had scarcely been exposed to vibration of the foot. The prevalence of coldness felt in the upper and lower extremities was greater than 90% in the VWF(+) group, about 60% in the VWF(-) group, and less than 10% in the referents. The extent of the coldness was greatest in the VWF(+) group. The skin temperature of both fingers and toes was lowest in the VWF(+) group, somewhat higher in the VWF(-) group, and highest in the referents both before and after immersion. These findings indicate that patients with vibration syndrome, especially those with VWF, have circulatory disturbances in the foot as well as in the hand. The disturbances in the foot may be related to long-term repeated vasoconstriction in the foot induced by hand-arm vibration through the sympathetic nervous system.

Aged↗
PubMed1991

Effect of vibration frequency on finger blood flow.

A total of 18 healthy subjects (9 men and 9 women) 20-35 years of age were used to study the effect of vibration frequency on finger blood flow. Seven vibration frequencies of 16, 31.5, 63, 125, 250, 500 and 1,000 Hz, at vibrational accelerations of 10 m/s2 (rms: root mean square) or 50 m/s2 (rms), with the exception of 16 Hz, which was measured at only 10 m/s2 (rms), were randomly applied to the palm of the right hand for 1 min at intervals of about 3 min. Finger blood flow was measured simultaneously in both the right and the left middle fingers with a blood flowmeter using a thermal diffusion method and in the left middle finger with a laser Doppler flowmeter. The experiments were performed in an artificial climate chamber set at 23 degrees C air temperature and 50% humidity. Relatively great responses were observed at frequencies of 31.5-63 and 250-500 Hz on the exposed and unexposed sides, respectively, as measured with a blood flowmeter using a thermal diffusion method and at 31.5-63 as well as 500 Hz on the unexposed side with a laser Doppler flowmeter. These results may be related to Meissner's and pacinian corpuscles.

Acoustics↗
PubMed1991

The deterioration of visual acuity by exercise under a mesopic vision environment.

Visual acuity deteriorated following 15-minute bicycle ergometer pedaling under the condition of a mesopic vision environment. Visual acuity decreased sharply as the load increased. The visual functions which changed significantly after the exercise in the mesopic vision environment were visual acuity (deterioration) and accommodative near point distance (extension).

Accommodation, Ocular↗
PubMed1991

Effects of color CRT display on pupil size in color-blind subjects.

The effects of color cathode ray tube (CRT) display on the pupil size in color-blind subjects were studied experimentally. Red, magenta, green, cyan, yellow, and white were presented on the CRT. Five protan subjects, five deutans, and five normal subjects were tested using infrared pupillography. In the protan group, the pupils were significantly less sensitive to red (wavelength: 600 nm) targets compared to the other colors. In the deutans and the control group, there were non-significant changes in pupil size in response to the colors. Dominant wavelengths above 600 nm in color CRTs should be avoided in routine work presentation because of less sensitivity in protanopias.

Adult↗
PubMed1991

[An autopsy case of cerebral sinus thrombosis which showed papilledema and was accompanied by idiopathic thrombocytopenic purpura].

In a 53-year-old woman with papilledema and idiopathic thrombocytopenic purpura (ITP) brain CT examinations failed to detect the cause of papilledema, pseudotumor cerebri was suspected and lumbo-peritoneal shunt operation was performed to decrease the intracranial pressure. Unfortunately the patient died of intracerebral hemorrhage. The autopsy revealed superior sagittal sinus thrombosis to be the cause of papilledema, which indicate that sinus thrombosis can develop with such a hemorrhagic disease as ITP.

Female↗
PubMed1990

Skin sympathetic activity in the tibial nerve triggered by vibration applied to the hand.

The effect of vibration applied to the hand on skin sympathetic activity (SSA) in the lower limbs was studied in five healthy subjects. SSA from the right tibial nerve at the popliteal fossa, plethysmogram from the right index toe and perspiration from the sole of the right foot were measured when vibration of 100 m/s2 at 60 Hz was applied to the left palm for 1 min. The SSA response to vibration exposure differed among subjects, but every subject showed an increase in SSA from the tibial nerve when vibration was applied to the hand. Decrease in amplitude of plethysmogram from the toe was also found in all subjects. One subject displayed a remarkable increase in perspiration on the sole of the foot together with a great increase in SSA. The present findings indicated that even vibration exposure of the hand triggers sympathetic activity in the tibial nerve innervating the foot, and causes vasoconstriction of the toe and perspiration on the sole of the foot.

Adult↗
PubMed1990

[Evaluation of a latex agglutination method for the rapid identification of Campylobacter jejuni/coli].

A latex agglutination assay was developed to identify Campylobacter jejuni and Campylobacter coli. We evaluated the specificity, reproducibility and utility of the assay for clinical use and the following results were obtained. 1) To prepare standardized antigen, bacterial cells must be suspended to a density of 1 to 5 McFarland unit, and heated at 121 degrees C for 10 to 30 min. 2) Bacterial cells may be suspended either in the solution provided with the kit, or in physiological saline, without affecting the results. 3) Of C. jejuni, 94 strains, 6 of C. coli, and 3 of "Campylobacter upsaliensis", all tested positive without exception. All other Campylobacter species, encompassing 13 species and 80 strains, were negative. An additional 9 species and 30 strains, of non-Campylobacter gram negative bacteria, isolated on the Campylobacter selection agar medium, also were uniformly negative. Based on these results, we conclude that bacteria testing positive with the kit can be identified as C. jejuni/coli. Interestingly, "C. upsaliensis", although isolated very rarely from the clinical specimens, also tested positive.

Campylobacter↗
PubMed1990

Leprosy and malignancy: autopsy findings of 252 leprosy patients.

The occurrence of malignant tumors in leprosy patients was studied in 252 autopsied cases. Malignant tumors were found in 33 out of 110 autopsy cases from 1962 to 1971, and in 51 out of 141 autopsy cases from 1977 to 1989 (until July). In 1974, a lepromatous case with Kaposi's sarcoma was autopsied. The incidence of malignant tumors in our 252 cases were 33.7% (85 out of 252). Carcinoma of the alimentary system was most common: stomach, liver and large intestine, in that order. There was an increased number of hepatocellular carcinoma closely related to liver cirrhosis. Carcinoma of the lung has increased remarkably in leprosy patients quite recently. Malignant lymphoma was the most common of the nonepithelial malignant tumors, and four of these cases were seen in lepromatous leprosy patients. Eight cases showed double or triple cancers; seven of these were autopsied during 1977 to 1989. Further studies should be done to ascertain which types of leprosy showed the highest incidence, and which sex showed more frequent malignant tumors.

Aged↗
PubMed1990

Limbal anesthesia for cataract surgery.

We present a new technique for the administration of anesthesia in cataract surgery. The technique consists of injecting 0.5 ml of locally-acting anesthetic subconjunctivally (or sub-Tenon's) along the superior limbal border. Using this method, we performed extracapsular cataract extraction (ECCE) with and without posterior chamber intraocular lens (PC-IOL) implantation or secondary PC-IOL implantation on 176 cataract patients. Anesthesia was successfully induced in the majority of these patients and all surgeries were carried out successfully with no major complications. Voluntary eye movements remained but did not interfere with surgery. On the contrary, they helped expose certain surgical sites. This new anesthetic method for cataract surgery is simple and minimizes complications attributed to other blind anesthetic techniques.

Adult↗
PubMed1989

Combined effects of vibration and noise on palmar sweating in healthy subjects.

The combined effects of vibration and noise on palmar sweating were studied experimentally in healthy subjects. Ten subjects were exposed to vibration at an acceleration of 100 m.sec-2 root mean square at a frequency of 125 Hz, a noise level of 105 dB(A) at a frequency of 1000 Hz and both stimuli together. Vibration was applied to the right hand and noise to both ears from headphones. Palmar sweating was measured by the ventilated capsule method. Vibration caused a marked increase in palmar sweating of the right hand directly exposed to vibration and also of the left hand not exposed to vibration. Simultaneous vibration and noise caused a greater increase in palmar sweating than by each of the factors separately. The combined effects tended to be greater in subjects who were more susceptible to vibration or noise.

Adult↗
PubMed1989

Histopathological changes of human tumors following thermoradiotherapy.

Twenty human malignant tumors treated with thermoradiotherapy were examined histopathologically. Hyperthermia was administered regionally with a 13.56-MHz or 8-MHz RF heating device, once or twice a week after irradiation, 2 to 12 sessions in total. Fifteen tumors received a total radiation dose of 26 to 70 Gy in fractions of 1.8 Gy to 2.0 Gy a day, 5 days a week, whereas five tumors received a total dose of 20 to 60 Gy in fractions of 4 Gy each, twice a week. Microscopic examination of 4 of the 20 tumors revealed complete necrosis throughout the cross-section of the entire tumor. All the four tumors had received a total dose of over 60 Gy and a tumor center temperature of over 42 degrees C. In 10 tumors, more than 50% but less than 99% of the cross-section of the entire tumor had massive coagulation necrosis. The remaining six tumors showed relatively little change; the area of intratumor necrosis was less than 50%. The grade of tumor necrosis was dependent on both the temperatures of tumor center and periphery, and a total radiation dose. The small blood vessels and capillaries in the tumor parenchyma were markedly damaged in 16 of the 20 tumors, while the blood vessels in the tumor stroma were damaged in only 2 tumors. Condensation of the destroyed nucleus observed in 15 tumors was considered to be a typical change induced by thermoradiotherapy. Viable tumor cells remained in the tumor central area in only four tumors and around the blood vessels in only three tumors. However, in the tumor peripheral area, viable tumor cells were observed in 16 out of the 20 tumors. These results indicate that histopathological changes induced by thermoradiotherapy are greater in the tumor central area than in the tumor peripheral area, and provide strong rationale for utilizing full dose radiation therapy in combination with hyperthermia as opposed to lower doses for cancer therapy.

Adult↗
PubMed1989

[Analysis of subjective symptoms of coldness and numbness in the upper and lower limbs among patients with vibration syndrome].

Coldness and numbness of the lower limbs in patients with vibration syndrome were studied in correlation with the frequency of attacks of vibration-induced white finger (VWF), coldness and numbness of the upper limbs, and awakening at night due to numbness of the arm. Subjects were 229 patients aged 50-69 years without disease other than vibration syndrome who had mainly operated chain saws. The present study showed that patients with more frequent VWF attacks had a higher prevalence and frequency of coldness in the fingers, awakening at night due to numbness of the arm, and coldness and numbness in the legs. Particularly patients having almost daily attacks of VWF had a high prevalence of these symptoms. Positive correlation was observed in prevalence and frequency between coldness of the fingers and that of the legs, and between coldness and numbness in the legs. The prevalence of VWF, numbness and coldness of the fingers, and coldness of the legs was higher the longer the total chain saw operating period. The present findings suggest that patients with severe circulatory disturbances in the upper limbs have severe circulatory disturbance in the lower limbs. Further studies on circulatory disturbances in the lower limbs are indicated, and their mechanism involved should be also pursued from the pathogenetic point of view.

Aged↗
PubMed1989

[Experimental studies on the combined effect of radiation and UFT 1. Radiosensitizing effect of UFT under single X-ray exposure].

The combined effects of X-ray and UFT, which is a mixture of tegafur (FT) and uracil, were studied using C3H mouse mammary carcinoma. Tumors were irradiated with a single dose of 1,000 R, 2,000 R one week after intramuscular transplantation. UFT (FT 15mg/kg+Uracil 33.6mg/kg) was intragastrically administered 2 hours before irradiation. In the group treated by combination of UFT and 1,000 R, the dose modifying factor (DMF) of UFT was 1.28 on the tumor growth delay and 1.64 on the survival time. A decrease in pulmonary metastases was found in the group treated by combination of UFT and radiation. It is suggested that UFT is a useful oral drug for combined treatment with radiation.

Animals↗