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Biomedical subjects

M Furuta

Publications and source records attributed to M Furuta.

At least 127 records · Page 7Linked to original sources
PubMed1993

[Ultrastructural study of guinea pig optic nerve head using the deep-etch method].

Normal guinea pig optic nerve heads were examined using the quick-freeze, deep-etch, rotary-shadow technique. This method visualized the three-dimensional organization of the cytoskeleton. The axon cytoplasm was composed of 20-25 nm in diameter microtubules (MTs) and 10-12 nm in diameter neurofilaments (NFs) with numerous cross-linkers. These cross-linkers spanned between adjacent NFs, adjacent MTs, and between NFs and MTs. The membranous organelles such as mitochondria, axoplasmic reticulum, or tubulo-vesicular structures also were attached to the NFs and MTs with the cross-linkers. Abundant intermediate filaments of 10-12 nm diameter within glial cell components segregated axon bundles from laminar collagen fibers. The laminar fibers contained interstitial collagens that were 30-60 nm in diameter with characteristic striae and sidearms, and 5-10 nm wide mesh-like structures connecting the collagen fibril bundles to a surrounding basal lamina.

Animals↗
PubMed1993

[Effects of prostaglandin E1 on temperature gradients between hand and foot during epidural anesthesia].

We studied the effects of prostaglandin E1 (PGE1) on hand-foot temperature gradients (foot temperature-hand temperature) induced by lumbar epidural anesthesia. Thirty-six ASA class 1 patients undergoing rotatory acetabular osteotomy were randomly assigned to receive 0 gamma (n = 13), 0.005 gamma (n = 10) and 0.02 gamma (n = 13) of PGE1. Thermometric probes were placed on the palm and sole of each patient. Bladder temperature was also monitored to evaluate the change of core temperature. Epidural catheter was indwelled at the level between L2 and L3 prior to induction and 2 % lidocaine was administered epidurally. All patients were warmed by water blanket at 37 degrees C and fluids for infusion warmed at 37 degrees C. Humidity and moisture exchanger was placed in breathing circuit. Hand-foot temperature gradients of patients given 0 and 0.005 gamma of PGE1 increased to 2.8 +/- 1.5 and 2.3 +/- 2.3 degrees C at extubation, respectively. In contrast, temperature gradient of patients given 0.02 gamma of PGE1 was 0.0 +/- 1.8 degrees C (P < 0.01). There was no difference among the values of bladder temperature in each group. The effects of PGE1 on mean arterial pressure, heart rate and central venous pressure were minimal. These data suggest that 0.02 gamma of PGE1 administration is effective to reduce hand-foot temperature gradient during epidural anesthesia.

Adult↗
PubMed1993

[Effect of substrate and diluent for factor VIII activity in highly purified factor VIII concentrate and patient plasma infused factor VIII concentrate].

We studied the difference between congenital factor VIII deficient plasma and factor VIII immuno-depleted plasma on the effect of pre-dilution for factor VIII activity determined by the one-stage assay. When standard curves of one-stage assay for factor VIII: C by GEORGE KING factor VIII deficient plasma (frozen at -80 degrees C), BEHRING factor VIII deficient plasma (lyophilized), DADE factor VIII depleted plasma (lyophilized, von Willebrand factor antigen 0.2 U/ml) and DADE factor VIII depleted plasma (lyophilized, von Willebrand factor antigen 1.0 U/ml) were compared, the difference between the clotting times for 100% and 6.25% of activity in each reagent were 39.5, 29.5, 25.0, 23.0 seconds respectively. Potency values in concentrates without albumin or von Willebrand factor showed a discrepancy between pre-dilution in Owren-Koller buffer and pre-dilution in factor VIII deficient plasma. Potencies of those products pre-diluted in Owren-Koller buffer were 40-60% lower than potencies pre-diluted in factor VIII deficient plasma. These results showed substrate and pre-diluent must be chosen carefully for the accurate assay of factor VIII activity in vitro for the highly purified factor VIII concentrates.

Adult↗
PubMed1993

[Effect of combined spinal and epidural anesthesia on blood loss during total hip replacement].

Ninety total hip replacements (THRs) performed by one surgeon were reviewed to compare the effects of different anesthetic techniques on the perioperative bleeding. Half of the THRs were performed under either combined spinal and epidural (CSE) anesthesia with lidocaine or general anesthesia with N2O/O2, vecuronium, enflurane or isoflurane. Deliberate hypotensive technique was not employed in any THR. All patients were female and had suffered from osteoarthritis of the hip joints. The patients in the two anesthesia groups were similar as to age, body weight, height, perioperative hemoglobin level, duration of anesthesia and operation, and blood transfusion requirement. A positive linear correlation existed between total operative blood loss and operation time in each group (P < 0.01). The rate of operative blood loss was significantly higher in the CSE anesthesia (6.2 +/- 3.0 ml.min-1) than in the general anesthesia (5.1 +/- 2.0 ml.min-1), while the amount of blood loss itself was without statistical difference. A significant increase in total volume of perioperative blood loss was also observed in the group with CSE anesthesia (1520 +/- 90 ml) compared with the general anesthesia group (1279 +/- 58 ml). These results show that spinal and/or epidural anesthesia can not always lead to reductions in operative blood loss during THR.

Aged↗
PubMed1993

[Effects of prostaglandin E1 on renal function during deliberate hypotension with epidural anesthesia].

We studied the effects of prostaglandin E1 (PGE1) on renal function during and after deliberate hypotension induced by epidural anesthesia. Twenty-seven ASA class 1 patients undergoing rotatory acetabular osteotomy were divided into three groups according to the dose of PGE1. Deliberate hypotension was induced and maintained during the surgery by epidural anesthesia combined with general anesthesia. PGE1 increased urine output and creatinine clearance (Ccr) during hypotension in dose dependent manner, and the changes were statistically significant compared with control at the dose of 0.02 micrograms.kg-1 x min-1 (gamma). PGE1 also tended to increase postoperative urine output and Ccr. Regardless of PGE1 administration, urine NAG/Cr ratio tended to increase during and after deliberate hypotension. Though total dose of local anesthetics was attenuated by PGE1, serum catecholamine levels of all patients were within normal ranges. In conclusion, PGE1 0.02 gamma is effective to maintain urine output during deliberate hypotension with epidural anesthesia. However, PGE1 is unlikely to prevent renal tubular damage at the dose less than 0.02 gamma.

Acetabulum↗
PubMed1993

[Optimal glucose dose in the preoperative fluid infusion].

We have measured blood concentrations of glucose, 3-hydroxybutyrate (3-OHBA), non-esterified fatty acid (NEFA) and lactate before and after glucose administration in 105 patients to determine the optimal glucose dose during the period of preoperative fasting state. The patients, scheduled for laparotomy in the afternoon, received fluid infusion containing an arbitrary glucose dose for 4 hours prior to surgery. The glucose dose showed a negative correlation with the ratio of 3-OHBA or NEFA prior to and after glucose administration (r = 0.40, r = 0.41 respectively, P < 0.05). There was no correlation between lactate ratio and glucose dose (r = 0.06). Glucose administration more than 0.4 g.kg-1 significantly suppressed 3-OHBA production (P < 0.05). Hyperglycemia (> 200 mg.dl-1) developed more often in the groups given 0.5 g.kg-1 or more glucose (P < 0.05), while significant hypoglycemia (< 60 mg.dl-1) occurred in the groups given less than 0.2 g.kg-1 of glucose (P < 0.05). This study demonstrates that preoperative infusion of glucose 0.4-0.5 g.kg-1 is useful to maintain the energy metabolism during the fasting state in patients scheduled for operation in the afternoon.

Adult↗
PubMed1993

[Anesthesia for a patient with red cell aldolase deficiency].

Aldolase deficiency of red blood cell is a rare cause of hereditary hemolytic anemia and now there exists only three patients in the world. We had a 24-year-old man operated on for gallbladder stone secondary to this uncommon disease. He underwent a cholecystectomy under general anesthesia combined with thoracic epidural block, using isoflurane, fentanyl, vecuronium, midazolam and lidocaine. During the surgery serum concentrations of bilirubin, free hemoglobin and LDH showed no change, suggesting a lower incidence of drug-induced hemolysis in the case of aldolase deficiency than in other enzyme deficiency. This fact also provides a useful guide to the choice of anesthetics and related agents. In the postoperative period, however, we found a hemolytic response to fever with a drop in hemoglobin level to 2.5 g.dl-1. Aldolase activity of his red cell is heat labile and an increase in body temperature may aggravate a disturbance in the glycolytic pathway leading to hemolytic crisis. It is thus important to prevent the body temperature from rising when a patient is suffering from hemolytic anemia due to red cell aldolase deficiency.

Adult↗
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↗