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Biomedical subjects

K Kashihara

Publications and source records attributed to K Kashihara.

At least 37 records · Page 2Linked to original sources
PubMed1999

Laminar cortical necrosis in central nervous system lupus: sequential changes in MR images.

A 44-year-old woman with systemic lupus erythematosus developed central nervous system lupus presenting with headache, fever, cloudiness of consciousness, and psychotic symptoms. T1-weighted and proton MR images showed laminar high intensity lesions in the parietal and temporal cortex bilaterally. T2-weighted images of the lesions showed low signal intensity. Treatment with corticosteroids alleviated the clinical symptoms within 7 months. The low T2 and high T1 signal abnormalities disappeared in a year and in 5 years, respectively. The laminar cortical lesions on MR images were suggested to represent cortical necrosis associated with central nervous system lupus.

Adult↗
PubMed1999

Circadian rhythm sleep disorder associated with pontine lesion.

A 55-year-old man presented with excessive daytime sleepiness and a circadian rhythm sleep disorder. Magnetic resonance imaging of the brain revealed a pontine lesion distinguishable from major cerebrovascular disease, demyelination and neoplasm. Benzodiazepines, antidepressants, methylcobalamine and thyroxine failed to synchronize the circadian rhythm. Antiepileptic drugs aggravated the condition, while melatonin and protireline partially relieved the patient from poorly controlled sleep disorder. A pontine lesion appeared to be related to the circadian rhythm sleep disorder of the patient.

Circadian Rhythm↗
PubMed1999

Differential regulation of AP-1 DNA-binding activity by D1 and D2 dopamine receptor antagonists in the rat caudate-putamen and globus pallidus following a unilateral 6-OHDA lesion of the medial forebrain bundle.

The effect of D1 and D2 dopamine receptor antagonists on the DNA-binding activity of the AP-1 transcription factor was studied in the rat caudate-putamen and globus pallidus following a unilateral 6-OHDA lesion of the medial forebrain bundle. In the caudate-putamen, vehicle-treated rats showed increased AP-1 DNA-binding activity, which appeared to be reversed completely by treatment with the D1 receptor antagonist SCH23390 (1 mg kg-1 i.p.) and partially by the D2 antagonist sulpiride (50 mg kg-1 i.p.). In the globus pallidus, vehicle and sulpiride did not induce AP-1, while SCH23390 increased it significantly. This induction was much more prominent in the 6-OHDA-lesioned hemisphere than in the intact hemisphere. The present study suggests that in the caudate-putamen, dopamine-depletion induces long-lasting enhancement of AP-1 DNA-binding activity via activation of D1 receptors and the simultaneous activation of D2 receptors facilitate it. However, in the globus pallidus of the 6-OHDA-lesioned hemisphere, D1 but not D2 antagonism induces AP-1 in certain cell populations which may be distinct from those expressing AP-1 upon stimulation of D2 receptors.

Animals↗
PubMed1999

Enhanced Fos expression in rat lumbar spinal cord cultured with cerebrospinal fluid from patients with amyotrophic lateral sclerosis.

The etiology of amyotrophic lateral sclerosis (ALS) remains unknown although an existence of neurotoxic substances in cerebrospinal fluid (CSF) from ALS patients have been postulated. In order to investigate a possible effect of CSF from ALS patients on cellular signaling in spinal neurons, we compared Fos-like immunoreactivity (Fos-LI) in organotypic cultures of rat lumbar spinal cord after addition of CSF from ALS patients or another neurologic disease. Fos-LI was normally present predominantly in dorsal horn neurons, whereas only a few ventral horn neurons were positive for Fos-LI. The number of Fos-LI positive neurons significantly increased in dorsal horn with addition of CSF from ALS patients as well as glutamate at 100 microM. However, the increase was not observed with addition of CSF from other neurologic diseases. The increase in Fos-LI positive neurons in dorsal horn was reversed by a further supplement of MK801, an N-methyl-D-aspartate (NMDA) receptor antagonist, but not of CNQX, an alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)/kainate antagonist. These results indicate that there may be substances in CSF from ALS patients that stimulate Fos expression in certain populations of spinal neurons via the NMDA receptors.

6-Cyano-7-nitroquinoxaline-2,3-dione↗
PubMed1999

An MR image of spinal cord sarcoidosis.

We present a case of spinal cord sarcoidosis with a unique magnetic resonance imaging (MRI) finding. MRI of the cervical spine revealed an unusual lesion of low signal intensity on T2-weighted image at the core of the lesion surrounded by high signal intensity. T1-weighted gadolinium enhanced image showed a high signal at the core lesion. Low signal intensity on T2-weighted image in the case was suggested to be due to hemosiderin deposition. Steroid therapy dramatically improved clinical symptoms with a marked reduction of peripheral T2 high intensity area and the core lesion size detected by gadolinium enhancement.

Aged↗
PubMed1999

D1/D2 receptor synergism on CREB DNA-binding activities in the caudate-putamen of rat.

Cyclic AMP-responsive element-binding protein (CREB) is a transcription factor that is activated by cyclic AMP-dependent protein kinase and regulates the induction of fos. In order to elucidate the cellular pathway of D1/D2 dopamine receptor synergism, the effect of D1 and D2 agonists on CREB DNA-binding activities was studied in the caudate-putamen of rats with an ipsilateral 6-hydroxydopamine-lesion of the medial forebrain bundle. Combined administration of D1 (SKF38393) and D2 (bromocriptine or quinpirole) agonists resulted in enhanced CREB-binding activities at a dose that did not enhance it when given separately. These results suggest that D1/D2 dopamine receptors play synergistic role in inducing CREB DNA-binding activities in the dopamine-depleted caudate-putamen of rats.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1999

[Huntington's disease: clinical and molecular genetics].

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by motor, cognitive, and psychiatric symptoms. An unstable CAG trinucleotide repeat expansion within the first exon of the responsible gene "IT15", encoding huntingtin, was identified. The clinical phenotype strongly correlates with the number of CAG repeat. The mutant huntingtin is expressed ubiquitously as same as the wild-type huntingtin, suggesting a toxic gain of function of the mutant huntingtin. The identification of huntingtin-interacting proteins and intranuclear aggregates containing a fragment of mutant huntingtin provide new insights into the pathophysiological mechanisms underlying HD. Moreover, the progress in transgenic animal models for HD will be critical for understanding the development of HD and for the testing of new therapeutics.

Animals↗
PubMed1999

Cochlear implantation for symptomatic hereditary deafness.

Recently, the effectiveness of cochlear implantation for hereditary deafness has been reported. We performed cochlear implantation for two patients with symptomatic hereditary deafness. Deafness in one patient was thought to be a result of albinism-deafness syndrome and in the other patient, a result of chronic progressive external ophthalmoplegia syndrome. Since their speech perception abilities improved dramatically, we believe that cochlear implantation should be actively performed for these two syndromes.

Adult↗
PubMed1998

Enhanced AP-1 binding in brain induced by D1 and D2 agonists in methamphetamine-sensitized rats.

The activator protein-1 (AP-1) binding activities induced by a separate challenge with SKF38393 and quinpirole after 1 weeks' abstinence from chronic methamphetamine (4 mg/kg/day, 14 days) were increased significantly in the striatum, nucleus accumbens and cingulate cortex compared with the saline-treated controls. Quinpirole-, but not SKF38393-induced AP-1 binding activities were still significantly higher after a 4-week abstinence period in the chronic methamphetamine group than in the chronic saline control group. Downward sniffing, which occurred following a quinpirole-challenge, was significantly intensified after both a 1 and 4 weeks' abstinence from chronic methamphetamine. These results indicate that chronic administration of methamphetamine induces alterations of the interactions of dopamine D1 and D2 receptors which are reflected as enhanced AP-1 binding activities.

Animals↗
PubMed1998

Radiation Complications Following Breast Conserving Therapy.

BACKGROUND: Breast conserving therapy is being established as a standard therapeutic procedure for early breast cancer in Japan. However, the indications of radiotherapy and a standardized therapeutic procedure have not been established yet. In this study, complications following radiotherapy were evaluated in patients who had previously undergone breast conserving therapy at Tokushima University Hospital. METHODS From October 1989 to March 1996, 60 women with stage I or II breast cancer underwent radiation therapy after breast conserving surgery, and all patients were followed-up for a median of 27 months. Radiation morbidity scoring of the breast and adjacent organs was performed using the toxity criteria of the Radiation Therapy Oncology Group (RTOG) and European Organization for Research andTreatment of Cancer (EORTC). RESULTS: Only 1 patient developed local recurrence, and no distant metastasisor death was observed. The cause of recurrence in 1 case was considered to be due to extended intraductal component. Although transient dermal reaction was induced by irradiation of the breast, no side effects that may cause cosmetic problems were found. No serious radiation complications were found in the lungs, ribs, heart or other adjacent organs. CONCLUSION: The adverse reactions caused by irradiation does not reduce the merit of combined use of radiation therapy in breast conserving therapy, and therefore, are not the hesitation factor in application of radiotherapy.

Journal Article↗
PubMed1998

L-DOPA does not facilitate nitric oxide production in the rat striatum and substantia nigra: in vivo microdialysis study.

Using in vivo microdialysis and flow-injection, we evaluated the production of nitric oxide (NO) in the striatum and substantia nigra of freely moving rats in response to challenge doses of L-dihydroxyphenylalanine (L-DOPA) by measuring the NO metabolite levels of nitrate and nitrite. The dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations also were determined in the same perfusates. Intraperitoneal injection of L-DOPA produced a significant, dose-dependent increase in the extracellular levels of dopamine and DOPAC in these areas, but did not modify the extracellular levels of the NO metabolites. An acute dose of L-DOPA does not appear to facilitate NO production in the rat striatum and substantia nigra.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1998

Kainic acid may enhance hippocampal NO generation of awake rats in a seizure stage-related fashion.

Temporal changes in kainate-induced seizure activity and hippocampal NO generation were evaluated simultaneously in conscious rats by using in vivo microdialysis and by determining the concentrations of nitrite and nitrate in perfusates. Intraperitoneal injection of kainic acid produced 'wet dog shake', focal seizure of the limbs and neck, hypersalivation, or generalized convulsion. These behavioral changes peaked at 120 min after the drug challenge and lasted for about 100 min. In contrast, the concentrations of NO metabolites, nitrite and nitrate, in the hippocampal perfusates increased rapidly and reached a plateau level at 40 min after the injection, and the level remained high for over 220 min. The increase was more marked in animals presenting severe seizures than those presenting mild ones. Pre-treatment with 25 mg/kg N(G)-nitro-L-arginine methyl ester promoted the severity of kainate-induced seizures, but it suppressed the increase in NO metabolites. These results suggest that kainic acid enhances hippocampal NO generation in a severity-related manner of the induced seizures. The enhanced NO generation upon kainate challenge appears mainly to be involved in seizure suppression.

Animals↗
PubMed1998

Reversible pitch perception deficit due to carbamazepine.

Carbamazepine (CBZ) is a drug frequently used to treat variety of neurological diseases or symptoms. Among its adverse effects, auditory disturbance is described rarely. In the present report, we describe an 18-year-old girl who noted false lowering of perceived pitch after starting CBZ treatment for epilepsy, and review the literature reporting CBZ-associated abnormal pitch perception.

Adolescent↗
PubMed1998

Hyperintense basal ganglia on T1-weighted MR images in a patient with central nervous system lupus and chorea.

We describe a patient with central nervous system lupus and choreatic movements in whom both basal ganglia showed high signal intensity on T1-weighted MR images, while the signal on T2-weighted images remained low. Within 8 months after onset, the choreatic movements had disappeared, with a corresponding decrease in the hyperintense T1 signal. The emergence of the choreatic movement disorder in this patient might have been related to the T1 hyperintensity of the basal ganglia, which, in turn, might have resulted from a vascular insult associated with central nervous system lupus.

Adult↗
PubMed1998

Presumed venous infarction in spinal decompression sickness.

We describe the serial MR imaging findings in a patient with spinal decompression sickness. In the acute phase, the spinal cord was swollen, with increased T2 signal in the posterior part of the column; 1 month later, marked contrast enhancement was noted in the same location; and 2 months later, the swelling and T2 signal had decreased. MR imaging may facilitate the early diagnosis of spinal decompression sickness.

Decompression Sickness↗
PubMed1997

Carcinoma of the uterine cervix with myocardial metastasis.

Cardiac metastasis from pelvic malignancies is rare. We experienced a case of carcinoma of the uterine cervix with myocardial involvement in the right ventricle, and treated this patient with conventional methods until her death. The metastatic tumor was incidentally found in the right ventricle, eroding the myocardium. We used CT, MRI, and gallium scintigraphy to assess the lesion. This aggressive lesion proved fatal for our relatively young patient. We report this case for future reference.

Adult↗