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Biomedical subjects

T Ohi

Publications and source records attributed to T Ohi.

At least 19 recordsLinked to original sources
PubMed1996

A deletion of five nucleotides in the L1CAM gene in a Japanese family with X-linked hydrocephalus.

X-linked hydrocephalus (HSAS) is the most common form of inherited hydrocephalus characterized by hydrocephalus due to stenosis of the aqueduct of Sylvius, mental retardation, clasped thumbs, and spastic paraparesis. MASA syndrome (mental retardation, aphasia, shuffling gait and adducted thumbs) and SPG1 (X-linked complicated spastic paraplegia) are also X-linked disorders with overlapping clinical signs. Linkage analysis studies implicated the neural cell adhesion molecule L1 (L1CAM) gene as a candidate gene for these X-linked disorders. This genetic study analyzes the L1CAM gene in a Japanese family with members suffering from HSAS, and describes a deletion of five nucleotides in exon 8. Screening by Bg1I digestion of polymerase chain reaction (PCR) products revealed that two siblings have the same mutation and a sister was identified as a heterozygous carrier. The 5 nucleotide deletion causes a shift of the reading frame and introduces a premature stop codon 72 nucleotides downstream, which might result in a truncated protein. The mutation identified herein is a novel L1CAM mutation, which triggers hydrocephalus. We report a unique L1CAM mutation that causes HSAS: the first report of such a mutation in a Japanese family.

Adult↗
PubMed1996

Distribution of and age-related changes in ciliary neurotrophic factor protein in rat tissues.

We developed a sensitive enzyme-linked immunosolvent assay for measuring ciliary neurotrophic factor (CNTF) and examined age-related changes in the CNTF contents of a variety of rat tissues during postnatal development. CNTF contents were substantially higher in the sciatic nerve and spinal cord than in the other tissues tested, the kidney coming third. In all the tissues except the sciatic nerve (90 ng/g), the CNTF content was less than 1 ng/g at 1 week of age, then gradually increased. It was highest at 5 weeks of age in the sciatic nerve (3171 ng/g), spinal cord (118 ng/g), and kidney (36.8 ng/g), after which it slowly decreased. In contrast, the maximum in the brain stem (9 ng/g) and cerebellum (3.6 ng/g) was at 8 weeks of age, whereas in skeletal muscle it was at 2 weeks of age (14.6 ng/g). These findings indicate that CNTF functions in the postnatal development of the rat.

Aging↗
PubMed1996

A catechol derivative (4-methylcatechol) accelerates the recovery from experimental acrylamide-induced neuropathy.

Acrylamide (ACR) monomer produces neuropathy of the dying-back type and 4-methylcatechol (4-MC) is a potent stimulator of endogenous nerve growth factor synthesis. In the present study, we investigated the efficacy of 4-MC in promoting recovery from experimental ACR neuropathy in rats. Twenty-two Sprague-Dawley rats were made neuropathic by ACR injections. They showed hindlimb paralysis, increment of landing foot spread distance and a statistically significant reduction in motor nerve conduction velocity. After the ACR neuropathy had been established, 12 of the rats were administered 4-MC for 2 weeks, and the other 10 were injected with phosphate-buffered saline alone. 4-MC-administered ACR neuropathy rats showed improvement, i.e., a decrease in landing foot spread distance, increase in motor nerve conduction velocity and increase in nerve growth factor content in the sciatic nerves in comparison with the corresponding values for ACR neuropathy rats given phosphate-buffered saline alone. A decreased number of large myelinated fiber with a reciprocal increase in small myelinated fiber number also was seen in the ACR neuropathy rats; however, this change was ameliorated in part by the administration of 4-MC. Therefore, these findings suggest that 4-MC can accelerate the recovery process clinically, electrophysiologically, biochemically and neuropathologically.

Acrylamides↗
PubMed1996

[A family with X-linked hydrocephalus resulting from mutations in the neural cell adhesion molecule L1].

We present the two siblings with X-linked hydrocephalus (XLH) and discuss the clinical features and genetical analysis of them. Case 1. The proband, a male, was delivered by the emergency cesarean section because of enlarged head circumference (44cm). His head circumference at 24 years old was 92cm. Neurological examination revealed adducted thumbs, horizontal nystagmus, hyperreflexia and spasticity of legs. He had tonic convulsions. MRI revealed a very thin layer of cerebral cortex. Molecular analysis revealed a deletion of 5 bases in exon 8 of the cell adhesion molecule L1 (L1CAM) gene located at chromosome Xq28. Case 2. The younger maternal half brother of case 1 was also born by the cesarean section, with 48cm in head circumference. A ventriculoatrial shunt was placed at the first month old. Epileptic seizures were seen. At the age of 21 years he had a head circumference of 59cm. A physical examination showed bilateral adducted thumbs, upward deviation of eyes, hyperreflexia and spasticity of legs. CT showed marked generalized ventricular enlargement including the fourth ventricle. Molecular analysis confirmed the same mutations as that of case 1. A maternal uncle had a previous diagnosis of hydrocephalus, and a sister is identified as a heterozygous carrier from molecular genetical analysis. Our results indicate that HLX is caused by the mutations in the gene for neural L1CAM in our family.

Adult↗
PubMed1996

Functional analyses of the stratum corneum in scars. Sequential studies after injury and comparison among keloids, hypertrophic scars, and atrophic scars.

OBJECTIVE: To characterize the functional properties of the stratum corneum (SC) of various scars. DESIGN: A prospective cohort study. SETTING: University hospital medical center. PATIENTS: Thirty-two consecutive patients surgically treated for various skin diseases and 26 consecutive patients with hypertrophic scars or keloids. MAIN OUTCOME MEASURES: Noninvasive bioengineering measurements of functional properties of the SC, such as transepidermal water loss (TEWL), high-frequency conductance, and SC turnover time. RESULTS: The SC barrier function assessed by TEWL was found to be a better parameter for the functional evaluation of scars than the hydration state of the skin surface measured by high-frequency conductometry. In general, the SC on the scars of deeper wounds in the dermis took longer to normalize functionally than the SC on the scars of superficial wounds, especially on the high compared with the abdomen. Thus, elevated levels of TEWL observed on scars at the donor sites of split-thickness grafts normalized between 200 and 400 days in contrast to fewer than 50 days for those of subepidermal erosions. Both TEWL and high-frequency conductance remained high in hypertrophic scars and keloids, and the SC involved showed a faster turnover time than that of adjacent normal skin. CONCLUSIONS: Scars, a proliferative change of the dermis, can be objectively evaluated according to functional abnormalities of the SC, because the dermis has a close relationship with the epidermis and with the SC. The functional characteristics of the SC of fresh scars and those of hypertrophic scars and keloids resemble those of retinoid-treated skin, rather than those found in epidermal hyperproliferative conditions such as psoriasis and dermatitis.

Abdomen↗
PubMed1996

[Two cases of severe bacterial meningitis with paranasal sinusitis followed by cerebrovascular disease--pathophysiology and treatment of cerebrovascular disease].

We report two cases of pneumococcal meningitis with paranasal sinusitis followed by cerebrovascular disease. Both cases were occupational divers, and had past histories of head trauma and paranasal sinusitis. Despite the combined therapy with antibiotics and dexamethasone, they developed cerebrovascular complications. Case 1 developed cerebral infarction and hemorrhage on day 13, and in case 2 cerebral infarction occurred on day 15. In both cases, serum levels of TNF-alpha and IL-6 were elevated in the early stage of the illness (12 pg/ml and 21.3 pg/ml in case 1, and 50 pg/ml and 7,570 pg/ml in case 2, respectively). In case 2, TNF-alpha, IL-1 beta and IL-6 levels in the cerebrospinal fluid were also elevated on day 4 (25 pg/ml, 320 pg/ml and 6,870 pg/ml, respectively). Thrombocytosis was observed in both cases before the onset of the cerebrovascular complications. These cytokines may play significant roles in thrombocytosis leading to cerebrovascular complications in pneumococcal meningitis. Although the use of steroids as adjunctive therapy for bacterial meningitis has been found to be beneficial, the dosage of dexamethasone administered in our cases may not be enough to suppress the synthesis and release of the cytokines. Therefore, administration of large doses of glucocorticoid should be recommended before the treatment with antibiotics.

Adult↗
PubMed1995

[A case of acute cerebellar ataxia with abnormal single photon emission computed tomography].

A 35-year-old woman complained of acute progressive speech and gait disturbance after an upper respiratory tract infection. Neurological examination revealed cerebellar dysarthria, horizontal saccadic pursuit and slow saccadic eye movement, marked truncal ataxia, generalized hyperreflexia and mild sensory impairment of the bilateral lower limbs. She was diagnosed as having acute cerebellomyelitis. We considered her status as acute cerebellar ataxia. The neurological signs and symptoms rapidly improved with intravenous administration of high dose of glucocorticoid. Single photon emission computed tomography (SPECT) using 99mTc-HMPAO was performed on the 9th day and 50th day from the neurological onset. It showed an increased accumulation of 99mTc-HMPAO in the bilateral cerebellar hemispheres and vermis on the 9th day in spite of normal findings of Gd-DTPA enhanced MRI. Less accumulation was seen on the 50th day when her neurological signs almost improved. The accumulation may suggest the inflammatory process of the cerebellum. SPECT can be a useful method for evaluating the severity of cerebellitis.

Adult↗
PubMed1995

Tissue expression of rat ciliary neurotrophic factor (CNTF) mRNA and production of the recombinant CNTF.

We used the polymerase chain reaction to show that CNTF mRNA is widely expressed in the brain, heart, lung, liver, kidney and testis of the rat, in addition to preferential expression in the sciatic nerve. We produced the recombinant CNTF in E. coli using rat sciatic nerve cDNA and obtained high yields of pure CNTF. The biological activity of the recombinant protein was comparable to that of native rat CNTF in its support of the survival of cultured embryonic day-8 chick ciliary ganglions. Western Blot analysis using antibody against the recombinant CNTF clearly showed the presence of CNTF protein (25kD) in rabbit sciatic nerve.

Animals↗
PubMed1995

Effects of 4-methylcatechol, a stimulator of endogenous nerve growth factor synthesis, on experimental acrylamide-induced neuropathy in rats.

Acrylamide monomer (ACR) causes central-peripheral distal axonopathy. We induced neuropathy in rats by means of ACR injection as an experimental model of the dying-back type of peripheral neuropathy to assess the potential efficacy of 4-methylcatechol (4-MC), a potent stimulator of endogenous nerve growth factor (NGF) synthesis, as a therapeutic agent for the axonal nerve lesion. ACR-induced neuropathy in rats resulted in a dying- back type of axonal degeneration, and a statistically significant reduction in motor nerve conduction velocity (MNCV), and density of large myelinated fibers. We administered 4-MC and ACR together to rats intraperitoneally and found improved clinical signs, and significantly more NGF content in sciatic nerves, faster MNCV, and greater myelinated fiber density than in rats given ACR alone. These findings suggest that 4-MC can prevent the progression of ACR-induced neuropathy and decreased NGF levels may be involved in the pathogenesis of ACR neuropathy.

Acrylamides↗
PubMed1994

The therapeutic effects of 4-methylcatechol, a stimulator of endogenous nerve growth factor synthesis, on experimental diabetic neuropathy in rats.

We investigated therapeutic effects of 4-methylcatechol (4-MC), a non-amine catechol compound, on streptozotocin (STZ)-induced diabetic neuropathy in rats. 4-MC is one of the potent stimulators of endogenous nerve growth factor (NGF) synthesis both in vitro and in vivo. Diabetic rats showed a statistically significant reduction in motor nerve conduction velocity (MNCV), mean myelinated axon diameter, and NGF content in the sciatic nerve during the experimental period of 8 weeks. The 4-MC treatment started 4 weeks after the STZ injection resulted in significantly greater NGF content, faster MNCV, and larger mean myelinated nerve fiber diameter and axon diameter than in untreated diabetic rats. These findings suggest that a decreased NGF level in the diabetic sciatic nerves may be involved in the pathogenesis of diabetic neuropathy and that 4-MC treatment could be useful for diabetic neuropathy.

Animals↗
PubMed1993

[Ballism, hemiballism].

Ballism, which is seen relatively infrequently among movement disorders, is characterized by the abrupt onset of vigorous, rapidly executed, poorly patterned in voluntary movement of the limbs. Hemiballism is mostly associated with the lesion in the subthalamic nucleus. However, it occasionally occurs as a result of lesions outside the subthalamic nucleus. The natural history of hemiballism caused by vascular subthalamic lesion usually shows gradual disappearance within days or weeks. Death from exhaustion has however been reported in some patients within four to six weeks after the onset. Hemiballism caused by lesions outside the subthalamic nucleus tends to persist for a longer period. Intensive treatment is therefore required. Successful treatments of hemiballism with haloperidol or chlorpromazine are wellknown, but, in older patients, sulpiride can be the first choice of medications because of its lesser side effect.

Cerebrovascular Disorders↗
PubMed1992

Effect of 4-methylcatechol on sciatic nerve growth factor level and motor nerve conduction velocity in experimental diabetic neuropathic process in rats.

This study examined the effects of 4-methylcatechol (4-MC), a nonamine catechol compound, on the neuropathic process of streptozotocin (STZ)-induced diabetic rats. 4-MC is one of the potent stimulators of nerve growth factor (NGF) synthesis at the cellular level and in cultured sciatic nerve segments of rats. Diabetic rats showed a statistically significant fall in sciatic motor nerve conduction velocity (MNCV) and a significantly reduced NGF content in the sciatic nerve (38.5 +/- 2.8% of control, P less than 0.01) during the experimental period of 4 weeks. 4-MC treatment of the diabetic rats for 4 weeks starting from the STZ injection elevated the NGF content (140% of untreated diabetic rats, P less than 0.05) and prevented the reduction in MNCV, but no effect on high blood glucose levels was seen. These findings suggest that decreased NGF levels in the sciatic nerve of the experimental diabetic rat may be involved in the development of the diabetic neuropathic process and that 4-MC, which can elevate endogenous NGF levels in vivo, may compensate for the inhibitory effect of STZ on the NGF level in progressive diabetic neuropathy.

Animals↗
PubMed1992

The spontaneous LH surge in ovarian hyperstimulation for assisted reproductive technology.

Thirty-seven patients who underwent assisted reproductive technology programme, in vitro fertilisation or embryo transfer and gamete intra-fallopian transfer, were randomised into two groups in order to evaluate frequency of premature spontaneous LH surge when stimulated with different type of hMG. An hMG (FSH:LH = 1:1) was administered for eighteen patients (group A) and the different highly purified hMG (FSH:LH = 19:1) was administered for nineteen patients (group B). Blood samples are drawn from day 3 of the cycle until hCG administration, and serum LH level are measured in the frozen samples. There were no statistical difference in the total amount of hMG used before hCG injection, days of hMG injection and the number of oocytes retrieved between two groups. The premature spontaneous LH surge occurred only one patient in group A (5.6%), but more frequent LH surge was observed in group B (42.1%) (p < 0.05). It is suggested that the different FSH/LH ratio may be the reason for the difference of the incidence of premature spontaneous LH surge.

Chorionic Gonadotropin↗
PubMed1992

[A case of myasthenia gravis occurring in the period of remission of chronic inflammatory demyelinating polyradiculoneuropathy].

A 31-year-old woman noticed progressive muscular weakness in the limbs and paresthesia in the fingers in February 1989. Paresthesia worsened and improved 4 times during 2 months. Intravenous edrophonium chloride failed to improve her muscular weakness. She had high antiacetylcholine receptor antibody titer in serum. We made a diagnosis of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) because of slow nerve conduction velocity (NCV), increased CSF protein, and the clinical course. Treatment with prednisolone improved muscular weakness and the slow NCV. Two years later she acutely had dyspnea, dysphagia, and muscular weakness after upper respiratory infection. Intravenous edrophonium chloride dramatically improved her symptoms. The diagnosis was made as myasthenia gravis (MG). After thymectomy her weakness was getting better without any medications. There may exist an autoimmune mechanism common, at least in part, to both CIDP and MG in our patient.

Adult↗
PubMed1991

[Significance of transrectal hyperthermia in the treatment of benign prostatic hyperplasia].

Though the local hyperthermia for the management of benign prostatic hyperplasia has drawn much attention as one non-surgical treatment, no definite conclusion could yet be obtained in terms of the efficacy. In this study local hyperthermia was induced in evaluable 33 cases with benign prostatic hyperplasia using Primus, and the effectiveness of this modality of treatment was investigated by analysing the subjective and objective response following hyperthermia. The prostate was heated trans-rectally up to 43 degrees C with 915 MHz microwave for one hour. Hyperthermia was carried out twice a week for ten times for the sake of thermotolerance. Urinary obstructive symptoms were divided into diurnal and nocturnal frequency, urinary urgency, the degree of urinary stream, hesitancy and dribbling. Each symptom was described before and after the treatment according to the scoring system. Moreover, objective changes of urinary flow and prostatic size were estimated by the residual urine volume, uro-flowmetry, rectal palpation of the prostate and echography. Hyperthermic treatment improved urinary flow markedly, but no appreciable alteration could be observed as to the size of the prostate. The overall efficacy, including subjective and objective response, could be summarized as 37% of effectiveness, and 33% of slight effectiveness, that is, 70% of effective ratio. As to the side effect, anal pain was noted in few cases of the present series. Therefore, transrectal hyperthermia may be a suitable modality for non-surgical treatment of benign prostatic hyperplasia.

Evaluation Studies as Topic↗
PubMed1990

[A case of hemiballism successfully treated by sulpiride, caused by lesions of the striatum].

A case of hemiballism caused by infarction in the left striatum on MRI was reported. Hemiballism is generally associated with lesions in the subthalamic nucleus. However, hemiballism occasionally occurs as a result of lesions outside the subthalamic nucleus. Hemiballism is a benign condition with spontaneous recovery in most cases, but hemiballism caused by lesions outside the subthalamic nucleus is reported to tend to persist for a long term. In our case without involvement of the subthalamic nucleus, hemiballism so far continued for three months since the onset. Successful pharmacological treatments of ballism with haloperidol or phenothiazines were well known. In our case, the treatments of ballism with these drugs were unsuccessful due to drug-induced hepatic dysfunction. Instead of these drugs, ballism was improved by administration of 150 mg of sulpiride per day with no side effects. Sulpiride may be beneficial for persistent hemiballism caused by the extra subthalamic lesions.

Aged↗