Search PubMed⌕ Search

Biomedical subjects

T Oishi

Publications and source records attributed to T Oishi.

At least 127 records · Page 7Linked to original sources
PubMed1990

Kainic acid and formoguanamine effects on environmentally-induced eye lesions in chicks.

Several neurotoxins are known which destroy some specific retinal component or other link in the visual pathway. We have employed such reagents to induce blindness in chicks, in order to explore the role of vision in the development of light-induced avian glaucoma (LIAG) and/or lid-suture myopia (LSM). Chicks made pharmacologically blind with formoguanamine failed to develop LSM. Under LIAG conditions, increased eye weight and global enlargement did not occur, but the characteristic anterior segment changes were seen. Thus LIAG globe enlargement, and LSM axial lengthening, appear to be vision-driven, but anterior segment changes are probably separately controlled. The retinal neurotoxin kainic acid rendered chicks behaviorally blind in the eye into which it was injected intravitrially, but this failed to prevent LIAG changes in either anterior segment or growth of the globe. Chicks reared under LSM conditions, and treated with kainic acid were not different from untreated controls, in that they developed globe enlargement in spite of their pharmacologically-induced blindness. Preliminary trials with quisqualic acid, another retinal neurotoxin, indicate that this agent, like kainic acid, cannot prevent LIAG eye enlargement. Several quis-treated eyes developed phthisis bulbi however, and thus could not be included among those assessed for eye weight and dimensional measurements.

Animals↗
PubMed1990

Reduction of nitroolefin using microorganisms.

Microbial reduction of 1-phenyl-2-nitro-1-propene (3) was carried out using 57 strains of yeast, 40 strains of aerobic and facultatively anaerobic bacteria and 40 strains of strictly anaerobic bacteria. Nine strains of yeast (Candida tropicalis, etc.,) had the ability to reduce (3) to 1-phenyl-2-nitropropane (1) (94.1%-60.3% yield). The ability of the aerobic and anaerobic bacteria was weaker than yeast (35.6%-14.0% and less than 5%, respectively). When 11 strains of strictly anaerobic bacteria (Clostridium innocuum etc.,) were used, a final reduced product like amphetamine (2) was detected, although the efficiency of reduction was very poor.

Alkenes↗
PubMed1990

Formation of amphetamine from its nitro analogue by anaerobic intestinal bacteria.

1. Microbial reduction of 1-phenyl-2-nitropropane 1 was carried out using 40 strains of intestinal anaerobic bacteria. Among them, 12 strains (Mitsuokella multiacidus, Clostridium perfringens, C. innocuum, C. clostiriiforme, C. difficile, C. butyricum, C. sp., Eubacterium limosum, E. aerofaciens, E. multiforme, Peptostreptococcus anaerobius and P. productus) had the ability to reduce 1 to amphetamine 2 (0.1-1% yield). 2. Clostridium species were more active than another intestinal anaerobic bacteria. 3. When Clostridium perfringens was used in preparative fermentation, the yield of 2 was increased, and its absolute structure had an (S)-configuration with an optical purity of 68% in enantiomeric excess.

Amphetamine↗
PubMed1990

[Experience in the use of Kyosera Injection Port as a kind of implantable reservoir (the second report)].

A total of 30 pieces of Kyosera Injection Port, as a kind of implantable reservoir, was used in 29 cases of liver tumor for an intermittent repeated chemotherapy. Of these 27 cases were actually used between Aug. 1st, 1986 and Aug. 31st, 1989. In this paper we studied the safety of the reservoir. The observation period averaged 259.4 days, with the highest of 760 days and the lowest of 29 days. The injection times averaged 12.7 times, with the maximum of 40 times and the minimum of one. The reservoir was placed under the laparotomy, and the cases which underwent cholecystectomy were 93.1%. 16 cases were treated with intraarterial infusion, and 14 with intraportal infusion. We investigated the complication of Kyosera Injection Port in 27 cases. As a result, there were no complication such as catheter occlusion and infection via catheter. But of 27 cases, 8 cases were recognized a complication, and the rate was 29.6%. Lumbago was noted during infusion chemotherapy in three cases, and on the other hand, there were steatolysis and necrosis of the tissue surrounding the implantation site, a movement of port, a catheter out of vessel, a leakage of the drug, and intraabdominal bleeding after taking off the catheter. But of 8 complication cases, only two cases were not able to inject drug. As a result, the rate of complication was 70.4% in over all. On the other hand, of 27 cases, there were 5 cases which recognized the complication caused by reservoir in itself. The safety rate was 81.5%. In such a circumstance this reservoir was very safe and seemed suitable to the implantable reservoir.

Adult↗
PubMed1990

[A case of hereditary motor and sensory neuropathy of neuronal type with retardation of motor development].

An atypical case of hereditary motor and sensory neuropathy of neuronal type with retardation of motor development was described. The patient was a 15-year-old boy who had suffered from distal muscle weakness with atrophy of four limbs and deformities of hands and feet since age 6 months. These symptoms were slowly progressive. He had never walked. His parents were not consanguinous. His parents and two siblings were unremarkable on neurological examination and on nerve conduction studies. On neurological examination, he showed severe degree of muscle weakness and atrophy in the distal upper and lower limbs, moderate degree of muscle weakness and atrophy in the proximal upper limbs and slight degree of made weakness and atrophy in the proximal upper limbs. Deep tendon reflexes in four limbs were decreased or absent. Vibration sensation was moderately decreased in the distal parts of four limbs. On the nerve conduction studies, no sensory nerve potential was recorded in the median, ulnar and sural nerves bilaterally. Motor nerve conduction velocity of the right tibial nerve was 21 m/sec and the amplitude of the compound muscle action potential (M-wave) was 0.15 mV, and no M-wave was elicited with the electrical stimulation of the median, ulnar and peroneal nerves. Neelde EMG showed fibrillation potentials and giant spikes with a reduction of the number of motor units. On sural nerve biopsy, the densities of both myelinated and unmyelinated fibers were severely decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Effects of photoperiod, temperature and testosterone-treatment on plasma T3 and T4 levels in the Djungarian hamster, Phodopus sungorus.

The effects of photoperiod, temperature and testosterone treatment on plasma T3 and T4 levels were investigated in the Djungarian hamster. Plasma T3 level was affected by temperature (25 degrees C less than 7 degrees C) but not by photoperiod. Plasma T4 level was affected by photoperiod (short day less than long day) at 25 degrees C. Administration of testosterone increased plasma T4 level under short photoperiod at 25 degrees C. Thus, higher plasma T4 level under long photoperiod at 25 degrees C might be induced by testosterone.

Animals↗
PubMed1989

Changes in the testicular binding of luteinizing hormone and plasma testosterone concentrations in the Djungarian hamster subjected to different photoperiods and temperatures and effects of long-term testosterone treatment on the binding.

The effects of artificial photoperiod, temperature, and long-term testosterone treatment on testicular luteinizing hormone (LH) binding were studied in adult male Djungarian hamsters. In hamsters transferred to long-day (LD; 16 hr light, 8 hr dark) photoperiod 8 weeks after adaptation in short-day (SD; 8 hr light, 16 hr dark) photoperiod of 25 degrees C, testicular growth was associated with an increase in the total LH binding per two testes and a decrease in LH binding per unit testicular weight. Plasma testosterone levels reached a peak 47 days after transfer to LD and tended to decrease thereafter, while the testes continued growing. In contrast, when hamsters reared under LD conditions at 25 degrees C for 12 weeks were transferred to SD, testicular regression was associated with a decrease in plasma testosterone and the total LH binding per two testes and an increase in LH binding per unit testicular weight. A significant decrease in LH binding per unit weight compared to SD controls was observed in those hamsters exposed to SD with continuous testosterone treatment. The testosterone treatment tended to induce decrease in the total LH binding. Scatchard plot analyses of the binding suggested that changes in LH binding were due to changes in the number of binding sites. When sexually mature male hamsters were subjected for 8 weeks to two different ambient temperatures (7 degrees C and 25 degrees C) and photoperiods (LD and SD), the difference between the two temperature groups was statistically not significant regarding the weights of testes, epididymides, and prostates; plasma testosterone levels; and LH binding in either LD or SD group. These results suggest that photoperiod is a more important environmental factor than temperature for the regulation of testicular activity and LH receptors and that testosterone reduces the number of LH receptors per unit testicular weight in adult male Djungarian hamsters.

Animals↗
PubMed1989

Selection experiment for increased egg production under 23 H and 24 H light-dark cycles in the domestic fowl.

A selection experiment was conducted for increased rate of lay under 23-h (23 HS line) and 24-h (24 HS line) light-dark cycles over 5 generations. In generation 5, rate of lay was higher in the 23 HS line than in the 24 HS line, and the proportion of hens with mean intra-sequence intervals of less than 24 h in the 23 HS line increased to 88% in the generation 5 from 15% in the base generation. The realised heritability for rate of lay was 0.25 plus/minus 0.04 in the 23 HS line and 0.15 plus/minus 0.05 in the 24 HS line. Egg weight and shell weight decreased in both lines, and the decrease in the proportion of shell was larger in the 23 HS line than in the 24 line. It is suggested that a regimen of 23 h light and dark may be an effective environment for selection to improve the laying performance of a population approaching a plateau for egg production.

Animals↗
PubMed1989

Stereoselective reduction of acetohexamide in cytosol of rabbit liver.

The stereoselective reduction of acetohexamide, an oral antidiabetic drug, was studied by using the cytosol of rabbit liver. A major metabolite of acetohexamide was isolated in 41.5% yield from the enzyme reaction mixture, and identified as (-)-hydroxyhexamide by techniques including the melting point, thin-layer chromatography, infrared spectrometry and optical rotation. The enantiomeric purity of (-)-hydroxyhexamide was determined on the basis of the proton nuclear magnetic resonance (400 MHz) spectrum of ester (diasteromer) derived by the reaction of (-)-hydroxyhexamide with (R)-(+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride. The (-)-hydroxyhexamide isolated from the enzyme reaction mixture was almost 100% in that enantiomeric form. The metabolic reduction of acetohexamide in the cytosol of rabbit liver appeared to be catalyzed by some enzymes with the same stereoselectivity.

Acetohexamide↗
PubMed1989

Ocular responses of genetically blind chicks to the light environment and to lid suture.

Blind rc chicks were examined as to growth characteristics of the developing eye. We also explored the relationship between hereditary blindness and two environmental interventions affecting eye development, light-induced avian glaucoma (LIAG) and the axial lengthening associated with lid-suture. Genetically blind rc chicks could be identified by their behavior even during the first hours after hatching. However, they retained the pupillary reflex, at least to 5 weeks of age. Blind chicks reared under a diurnal lighting schedule had eyes 18% larger (by eye weight) than sighted hatchmates, with corresponding increases in globe diameters. Of the anterior segment parameters, neither corneal diameter, anterior chamber depth nor corneal curvature was demonstrably different from sighted controls. When rc chicks were reared under continuous light, the environmental condition which brings on LIAG, their already enlarged eyes showed no superimposed increases in either eye weight or globe dimensions. The corneas showed some characteristic LIAG effects: small anterior chamber depth and increased corneal radius of curvature (flat cornea), as compared with diurnal rc birds. Some birds were subjected to unilateral eyelid-suture, a protocol which usually induces axial lengthening and corneal bulging. Blind rc birds did not respond to this surgical intervention: in comparison by paired t-test between sutured and contralateral eye, there was little or no difference in eye weight, globe diameters or anterior segment parameters. Thus vision, or at least an intact retina/RPE, seems to be necessary for development of the characteristic axial lengthening in response to eyelid suture. The globe enlargement of LIAG also appears to be vision-dependent, although the anterior segment manifestations of LIAG are systemic effects.

Animals↗
PubMed1989

[Study on the trophic effect of camostate mesilate on ethionine-induced pancreatic injury rat].

Pancreatic injury was induced to rats with intraperitoneal injection of ethionine 60 mg per 100 g BW twice or three times weekly for 6 weeks. These rats were given 100 mg/kg of Camostate mesilate (CM) via a gastric tube daily for 14 days. CM administration resulted in an increase of pancreatic wet weight, hypertrophy and hyperplasia of acinar cells, and an increase of exocrine pancreatic function. Acini prepared from CM and ethionine-treated rats exhibited increased response to caerulein, but decreased sensitivity to caerulein. The plasma CCK level in rats with CM administration 24 hours later was higher than that without CM administration. However, there were no significant changes in plasma CCK and secretin level thereafter. We concluded that CM had a trophic effect on the pancrease with ethionine-induced pancreatic injury, and CCK was considered playing the same role in injured pancreas as the normal rat pancreas. Studies using CCK receptor antagonist are needed for further clarification.

Administration, Oral↗
PubMed1989

[A case of multiple sclerosis with polyradiculitis and spinal subarachnoid block].

A case of 53-year-old female with multiple sclerosis was reported. In August 1987, she suffered from weakness in her legs and urinary retention. These signs had progressed with incomplete remissions and exacerbations. In March 1988, she developed sensory loss of all modalities below C2 level, spastic paralysis of upper extremities and flaccid paraplegia of lower extremities. Electromyography showed evidence of denervation in affected muscles of all extremities and paraspinal muscles. On lumber puncture, spinal fluid pressure fell to 0 mmH2O after removal of the spinal fluid of 12 ml, and the CSF protein was 740 mg/dl, indicating subarachnoid space block. The oligoclonal band was positive. MRI showed swelling in the cervical and upper thoracic cord, and multiple lesions in the periventricular white matter in the cerebrum. We diagnosed this case as multiple sclerosis in combination with acute polyradiculitis. The spinal subarachnoid block was considered to be caused by the swelling of the spinal cord.

Acute Disease↗
PubMed1988

Variations in the disappearance rate of indocyanine green.

Time-associated changes in the disappearance rate of indocyanine green from the blood (K.ICG) as an index of liver function, were studied. Blood was drawn 5 times at 3-minute intervals from 32 patients. Early, intermediate, and late K.ICG values were 0.087 +/- 0.040, 0.082 +/- 0.038, and 0.076 +/- 0.033 min-1, respectively, showing serial decreases. When blood was drawn 8 times at 2-minute intervals from 22 other patients, the means of the K.ICG values at 11 time points showed a nearly linear relationship (r = -0.986). These findings indicated that K.ICG is approximated by a linear function of time, K(t) = -K'.t + K0. According to this function, K.ICG is considered to decrease by 1.96% every minute. The K.ICG value determined by the conventional method is, therefore, a mean disappearance rate of 15 minutes, and K0 is considered to reflect the initial reaction speed.

Cholestasis↗
PubMed1988

Effects of photoperiod and temperature on the binding of follicle-stimulating hormone (FSH) to testicular preparations and plasma FSH concentration in the Djungarian hamster, Phodopus sungorus.

The effects of artificial photoperiod and temperature on testicular FSH binding and plasma FSH levels were studied in adult male Djungarian hamsters. In Exp I, hamsters were transferred to long day (LD) photoperiods (16-h light, 8-h dark) after 8 weeks of adaptation in short day (SD) photoperiods (8-h light, 16-h dark), but the ambient temperature was maintained at 25 C throughout the experiments. A marked increase in the total FSH binding per two testes occurred between 10 and 47 days after transfer to LD, a change that was accompanied by testicular growth. Binding of FSH per testicular weight decreased during the same period. Scatchard plot analyses of the parameters indicated that LD decreased both the concentration of FSH binding sites and the equilibrium dissociation constant (Kd). Plasma FSH levels increased between 10 and 47 days after transfer to LD. In contrast, when hamsters reared under LD for 12 weeks were transferred to SD (Exp II), FSH binding per unit weight basis increased 19 weeks after transfer to SD, but the total binding per two testes decreased markedly. In Exp III, sexually mature male hamsters were subjected to different ambient temperature and photoperiods. There were no significant effects of different ambient temperatures on the testicular weight and testicular FSH binding in animals exposed for 8 weeks to either LD or SD. However, plasma FSH levels of hamsters maintained at 25 C under LD was significantly higher than FSH levels at 7 C under LD. A similar effect of temperature on plasma FSH levels was observed in hamsters under SD. The present study indicates that photoperiod is a more important environmental factor than temperature for the regulation of FSH receptor in the Djungarian hamster.

Animals↗
PubMed1988

Chicks blinded with formoguanamine do not develop lid suture myopia.

The involvement of the retina in avian lid suture myopia was investigated by use of formoguanamine (FG), which induces blindness in chicks, characterized by damage to the retinal pigment epithelium and photoreceptor layers. In control chicks reared under a diurnal lighting schedule of 12L/12D, unilateral eyelid suture at 3 days of age induced a typical lid suture myopia response on the operated side (eye enlargement and bulging cornea) by 4 wks. of age. On the other hand, in FG-treated blind chicks also reared under 12L/12D, there was no difference in eye parameters, between sutured and non-sutured eyes. All globe parameters measured were very similar in FG-treated and control non-sutured chicks. Corneal diameter and anterior chamber depth in the eyes of FG-treated chicks were significantly smaller than in non-sutured control eyes.

Animals↗