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Biomedical subjects

M Kunimoto

Publications and source records attributed to M Kunimoto.

At least 19 recordsLinked to original sources
PubMed1995

Possible involvement of the 440 kDa isoform of ankyrinB in neuritogenesis in human neuroblastoma NB-1 cells.

Two isoforms of brain ankyrin, 440 kDa and 220 kDa ankyrinB, which are products of alternatively spliced pre-mRNA encoded by a single gene, are both expressed in human neuroblastoma NB-1 cells. Expression of the polypeptide and mRNA of the larger isoform increased upon induction of neurite outgrowth in NB-1 cells by dibutyryl cAMP, while those of the smaller isoform were unaffected. The expressed 440 kDa ankyrinB was concentrated at the tip of growing neurites and was partly co-localized with GAP-43. These results suggest that 440 kDa ankyrinB is one of the neuronal growth-associated proteins and provides an interesting example of gene regulation by alternative splicing in neuronal cells.

Alternative Splicing↗
PubMed1995

Interleukin-1 alpha mediates the enhanced expression of intercellular adhesion molecule-1 in pulmonary epithelial cells infected with respiratory syncytial virus.

The mechanisms of virus-induced enhancement of intercellular adhesion molecule-1 (ICAM-1) expression in epithelial cells are unknown. In the present study, the effect of respiratory syncytial virus (RSV) infection on the expression of ICAM-1 in human pulmonary type II-like epithelial (A549) cells was evaluated. Conditioned RSV media (cRSV) produced from growth of RSV in A549 cells induced a significant increase in the expression of ICAM-1. Treatment of the cells with noninfectious cRSV prepared by ultraviolet (UV) irradiation (UV-cRSV) or ribavirin treatment resulted in the expression of ICAM-1 to a similar extent as infectious cRSV. These results suggested that RSV induces the synthesis of a soluble mediator(s) that regulates the expression of ICAM-1. Cytokine analysis by immunoassay and polymerase chain reaction showed that RSV induces the synthesis of interleukin (IL)-1 alpha and -beta, and tumor necrosis factor alpha (TNF-alpha). Preincubation of UV-cRSV with soluble IL-1 receptor (sIL-1r) almost completely blocked the enhancement of ICAM-1 expression. Furthermore, simultaneous incubation of infectious purified RSV with sIL-1r resulted in a significant reduction in enhancement of ICAM-1 expression. Preincubation with neutralizing antibodies to IL-1 alpha and -beta, and TNF-alpha showed that the predominant ICAM-1 enhancing soluble mediator in UV-cRSV was IL-1 alpha. These experiments provide direct evidence for an autocrine mechanism of enhanced ICAM-1 expression in RSV-infected epithelial cells that is mediated primarily by IL-1 alpha. Pulmonary epithelial cells may play an important immunoregulatory role in the microenvironment of the lower respiratory tract infected with RSV.

Cell Adhesion↗
PubMed1995

[A case of carpal tunnel syndrome caused by a ganglion cyst--diagnosis and follow-up study with magnetic resonance imaging].

We report a case of carpal tunnel syndrome (CTS) caused by a ganglion cyst which was diagnosed by magnetic resonance (MR) imaging of the left wrist. MR images depicted a 10-mm ganglion cyst which pressed the median nerve toward the ulnar side. The ganglion cyst was punctured under direct endoscopic visualization in the carpal canal, subsequently the clinical and the electrophysiologic findings of CTS improved. The median nerve was delineated in its proper position. MR imaging of the wrist, a noninvasive means to observe median nerve, is useful for the diagnosis and the follow-up study of CTS.

Adult↗
PubMed1992

Effect of L-threo-3,4-dihydroxyphenylserine on muscle sympathetic nerve activity in humans.

To clarify the effect of L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS), a precursor of norepinephrine (NE), the effect of this drug on microneurographically recorded muscle sympathetic nerve activity (MSA) from the tibial nerve was analyzed in ten healthy male volunteers. A single dose of 600 mg of L-threo-DOPS was orally administered and the effect of this norepinephrine precursor on MSA at resting and at upright standing positions, as well as the MSA responsiveness to head-up tilting was examined by comparing the data obtained after administration of the drug with those obtained under control conditions. The plasma NE levels were determined in two subjects. The results were as follows: (1) resting MSA increased significantly 80 min after administration of L-threo-DOPS and was accompanied by an increase in plasma NE levels; (2) standing MSA when treated with the drug was not significantly different from values obtained under control conditions; and (3) MSA responsiveness to orthostasis was reduced after L-threo-DOPS. We conclude from the activation of MSA by L-threo-DOPS that this drug raised blood pressure not only through an increase in metabolized plasma NE levels, but also through the enhancement of MSA by activation of descending noradrenergic or adrenergic pathways proximal to the recording site of the sympathetic discharge.

Adult↗
PubMed1992

One-step typing of Epstein-Barr virus by polymerase chain reaction: predominance of type 1 virus in Japan.

The prevalence of two types of Epstein-Barr virus (EBV) in Japan was studied by using the polymerase chain reaction (PCR). The U2 region encoding EBV nuclear antigen 2 (EBNA-2) was chosen as the target of amplification. Consensus primers were synthesized from sequences common to the two types but encompassing a large stretch of deletion in the sequence of type 1 EBV. The primers were capable of amplifying both types at the same time but allowed differentiation of each type by the size of the amplification products. Thus we could carry out detection and typing of EBV in a one-step PCR. EBV was detected in mouth washings of 21 (23%) of 91 seropositive healthy adults. Twenty samples (22%) contained type 1 and only one (1%) type 2. Seventy-nine patients suffering from various types of tonsillitis were also studied. EBV was detected in mouth washings of 37 patients (47%). Thirty-four (43%) contained type 1 and three (4%) type 2. Double infection was not seen in either healthy donors or patients. These results indicate that type 1 EBV is highly dominant and the type 2 variant is quite rare in Japan.

Base Sequence↗
PubMed1992

Impaired long-term T cell immunity to Epstein-Barr virus in patients with nasopharyngeal carcinoma.

The long-term T cell immunity to Epstein-Barr virus (EBV) is considered to play an important role in suppressing proliferation of EBV-infected B cells and outgrowth of EBV-associated tumors. It can be manifested and quantified by the EBV-induced focus regression assay. In the present study, we examined the strength of T cell immunity to EBV in patients with nasopharyngeal carcinoma (NPC) and other cancers originating from the head and neck region. In contrast to patients with other types of cancers, including EBV-negative NPC, patients with EBV-positive NPC were found to have a profound impairment in the long-term T cell immunity to EBV.

Adolescent↗
PubMed1992

Neuro-effector characteristics of sweat glands in the human hand activated by irregular stimuli.

Intraneural electrical stimulation of cutaneous fascicles in the median nerve was performed in 24 normal subjects and the effects on sweating within the innervation zone were monitored as changes of skin resistance and water vapour partial pressure (wvpp). The aims were: (1) to investigate the response variability between repeated stimulation sequences in the same skin site and between different sites and (2) to compare quantitative effects of regular and irregular stimulation on skin resistance and wvpp. Regional axillary anaesthesia of the brachial plexus eliminated spontaneous and reflex sympathetic activity. With repeated irregular stimulation sequences skin resistance responses from the same skin site varied only slightly between trials. Differences between response curves from two skin sites in the same subject or from different subjects were also small but significantly greater (P < 0.01) than differences between responses to repeated stimulation in the same site. Irregular stimulation with average frequencies of 0.49 Hz and 3.51 Hz gave greater resistance responses than if the same number of stimuli were delivered regularly (P < 0.01). The difference was most pronounced at 0.49 Hz. At an average frequency of 0.49 Hz the stimulation usually evoked no changes of wvpp whereas an average frequency of 3.51 Hz caused an increase of wvpp which was greater with irregular than with regular stimulation in all subjects. We conclude that: (1) sweat responses to sudomotor nerve traffic vary slightly due to local factors in the skin or the terminal nerve endings and (2) irregular sudomotor nerve traffic evokes more sweat than if the same impulses occur regularly.

Adult↗
PubMed1992

Non-linearity of skin resistance response to intraneural electrical stimulation of sudomotor nerves.

Intraneural electrical stimuli (0.3 mA, 0.2 ms) were delivered via a tungsten microelectrode inserted into a cutaneous fascicle in the median nerve at the wrist in 16 normal subjects, and the effects on the sweat glands within the innervation zone were recorded as changes of skin resistance. In order to examine the relationship between the skin resistance level and the amplitude of transient resistance responses, trains of high frequency stimulation were used to reduce the skin resistance level and then transient resistance responses were evoked by single stimuli at 0.1 Hz. Regional anaesthesia of the brachial plexus in the axilla eliminated spontaneous sympathetic activity and reflex effects. At high skin resistance levels response amplitudes to single stimuli were low but they increased successively to a maximum at intermediate levels and then decreased again at low resistance levels. Repeated stimulation sequences evoked qualitatively similar response curves but quantitatively both response amplitudes and skin resistance levels were slightly reduced upon repetition. We suggest that the changes of response amplitudes are due to variable resistivity of the corneal layer. The shifts of the response curves with repetition of stimulation may result from increased hydration of the corneum. It is concluded that the variability of response amplitudes to constant stimuli makes the amplitude of a skin resistance response unsuitable as an indicator of the strength of sympathetic sudomotor nerve traffic.

Adult↗
PubMed1992

[A case of transfusion-associated GVHD after total laryngectomy].

We report a case of fatal transfusion-associated graft versus host disease (GVHD) that developed in a patient with laryngeal cancer. After a 39.6Gy irradiation dose, total laryngectomy with right radical neck dissection was performed. The postoperative course was uneventful. However, seven days after blood transfusion, high fever (38.5 degrees C) suddenly appeared. On the ninth day, watery diarrhea and facial erythema were observed. On the 12th day, liver disturbance and pancytopenia developed. The patient died on the 16th day because of overwhelming sepsis. Transfusion-associated GVHD has a mortality rate of more than 90%. Therefore, the most important procedure for preventing GVHD is the use of irradiated blood products. Furthermore unnecessary blood transfusion should be avoided.

Graft vs Host Disease↗
PubMed1992

Diagnosis of aneurysm of superior thyroid artery by CT and MR imaging.

A 51-year-old man presented with a nonpulsatile anterior neck mass which suggested a thyroglossal duct cyst. At CT a small cystic mass was revealed. The mass contained a well-defined, crescent-shaped, low-density area with homogeneous contrast enhancement. On MR T2-weighted spin-echo and gradient-echo images the mass was as hyperintense as the neck vessels. Angiography and operation confirmed an aneurysm of the left superior thyroid artery with a mural thrombus.

Aneurysm↗
PubMed1992

[A ruptured aneurysm at the peripheral collateral circulation of the anterior choroidal artery in a patient with moyamoya disease: a case report].

This 42-year-old man experienced a sudden onset of occipital headache. Neurological examination revealed a moderately disturbed consciousness and a moderate left hemiparesis. CT scan disclosed a hugh hematoma in the right temporo parietal lobe without intraventricular hemorrhage. A cerebral angiography demonstrated typical findings of moyamoya disease and a small saccular aneurysm at the peripheral portion of the right anterior choroidal artery, which was dilated at the collateral circulation to the parietal lobe. The hematoma was removed at once by a craniotomy. He became alert but mild hemiparesis persisted. MRI disclosed a small signal-void lesion lateral to the trigone of the right lateral ventricle. The angiography repeated three weeks after the removal of the hematoma showed the unchanged size of the aneurysm. Direct surgery for the aneurysm was performed via the right parietal transcortical approach. The aneurysm was reached under the guidance of the intraoperative angiography. Trapping of the parent artery and the excision of the aneurysm were performed. On the basis of the presence of an internal elastic lamina at the neck of the aneurysm, the surgical specimen was histologically verified to be a true aneurysm. Since the collateral circulation was well preserved during surgery, no worsening of the neurological manifestation was observed. In view of the unfavorable prognosis for a moyamoya patient with this type of the aneurysm, which often results in a massive ventricular or intracerebral hemorrhage, surgery directed to the aneurysm itself should be considered.

Adult↗
PubMed1992

[A septated syringomyelia with a dramatic clinical course in a young patient with MELAS; a case report].

This is a report of a young girl who showed a recurrence of acute worsening and remission of neurological manifestations, with consistent MRI demonstration of transaxial septated syrinxes in the cervical and the lumbar spinal cord in addition to a tight filum terminale. This 8 year-old girl had developed normally since her birth until August 1989 when she developed a gait disturbance. This worsened acutely on January 1, 1990, with the additional manifestation of a urinary bladder disturbance. General examination failed to show any abnormality or scoliosis. Neurologic examination revealed a monoparesis of the right lower extremity with muscle atrophy and pyramidal tract sign. Fecal constipation and urinary retention were noted. The MRI T1 weighted sagittal image demonstrated an incontinuous low intensity signal in the C1-C7 as well as in the T12-L2 without swelling of the cord. The axial image clearly demonstrated the septations in the syrinx which looked like eye glasses. No definite Gd enhancement was demonstrated. Chiari malformation was not associated, but the tethered cord was well identified. With the administration of steroid, she showed a marked improvement of neurological manifestations. She was able to urinate without difficulty and also walk by herself. For one month thereafter she remained well with minor neurological deficits until she developed a worsening of the gait disturbance with a newly manifested weakness of the left upper extremity. Sensory impairment was also demonstrated below L3. In contrast to the worsening of the clinical symptoms, no definite change in the abnormalities found by MRI was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Acidosis, Lactic↗
PubMed1991

In vivo benzodiazepine receptor occupancy by CL 218,872 visualized by positron emission tomography in the brain of the living baboon: modulation by GABAergic transmission and relation with anticonvulsant activity.

In vivo benzodiazepine receptor occupancy by increasing doses of CL 218,872 has been evaluated in the baboon Papio papio, using (11C) RO 15-1788 as specific radioligand and positron emission tomography as external detection system. Although BZR heterogeneity has been previously demonstrated in the brain of the living baboon using PET, we did not observe in our studies that CL 218,872 interacts preferentially with one of the BZR subtypes. The monophasic pattern of the dose dependent CL 218,872 displacement curve and the corresponding "in vivo Hill coefficient" near unity suggest that CL 218,872 binds in cerebral baboon cortex with a similar affinity with BZ1 as well as BZ2 subtypes. The anticonvulsant properties of CL 218,872 against bicuculline and allylglycine-induced seizures were correlated with benzodiazepine receptor occupancy by assessment of electroencephalographic activity during positron emission tomography studies. Our data confirmed in vivo the hypothesis of a partial agonist anticonvulsant activity of CL 218,872. At the same time, the use of a GABA-antagonist (bicuculline) or an inhibitor of the GABA synthesis (allylglycine) suggested the existence of an allosteric interaction between benzodiazepine receptors and GABA receptors.

Allylglycine↗