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Biomedical subjects

S Hirai

Publications and source records attributed to S Hirai.

At least 37 records · Page 2Linked to original sources

Granular cell tumor of the urinary bladder.

A case of granular cell tumor of the urinary bladder is reported. A 48-year-old Japanese man with a bladder tumor underwent transurethral resection of the tumor and microscopic examination showed a granular cell tumor. Immunohistochemical staining for neuron specific enolase and S100 protein was positive, and it was suggested that the granular cell tumor was derived from Schwann cells.

Granular Cell Tumor↗

Natural history of sigmoid colon cancer: report of a patient observed for 4 years.

We report a case of sigmoid colon cancer that was left untreated for a period of 4 years, because the patient declined treatment. A 59-year-old man was found to have an early carcinoma of the sigmoid colon measuring approximately 12 mm in diameter. The lesion, initially a flat cancer, increased in height and became sessile 4 months later. Subsequently, the central portion of the lesion became ulcerated, leaving an elevated ring along its periphery. The lesion eventually evolved into an ulcerated, invasive cancer. This sequence has not been observed with colonoscopy before.

Adenocarcinoma↗

Masseter inhibitory reflex in amyotrophic lateral sclerosis.

OBJECTIVES: To elucidate underlying abnormalities of the masseter motor system in amyotrophic lateral sclerosis (ALS). METHODS: We recorded biphasic EMG suppressions of the masseter muscle (silent or inhibitory periods 1 and 2) after electrical stimulation of the mental nerve during maximum clenching of the teeth in 16 ALS patients and 15 healthy control subjects. We also examined the recovery cycle of the silent periods by delivering paired stimuli with an interstimulus interval of 250 ms. RESULTS: Silent period 1 in the patients was not significantly different from that in control subjects, whereas silent period 2 (as measured by its area on the graph) was increased in the patients, especially with exaggerated jaw jerk. Only two patients showed absence of silent period 2. The recovery cycle of silent period 2 in the subgroup of patients with exaggerated jaw jerk was significantly lower than the control value. CONCLUSIONS: The abnormalities of the masseter inhibitory reflex in ALS could be ascribable to involvement of the corticobulbar or corticoreticular tract projecting to the inhibitory interneurons mediating silent period 2.

Adult↗

Effect of multiple subpial transection on motor cortical excitability in cortical dysgenesis.

We report here a 12-year-old patient with unilateral cortical dysgenesis and intractable simple partial seizure in his left arm, who underwent multiple subpial transection (MST) in the right cerebral cortex including the primary motor cortex. We investigated motor cortical excitability using multimodal transcranial magnetic stimulation (TMS) before and 1 month after MST, in which surgical cortical incisions were made with strokes 5 mm apart and 4 mm deep. Preoperative TMS studies showed hyperexcitability in the affected motor cortex as abnormally prolonged muscle responses to TMS with a wide cortical motor map, which were markedly reduced following the operation. The preoperative motor evoked potentials were large and polyphasic, and consisted of early and late components. The late component was completely abolished after MST, suggesting that this component might be due to activation of the corticospinal tract neurones by long recurrent axon branches of dysplastic excitatory pyramidal neurones, which were cut by MST, or by delayed, polysynaptic intracortical conduction with marked temporal dispersion. Intracortical inhibition in the affected motor cortex was also disrupted preoperatively and improved after MST. Postoperative recruitment order of muscle responses to TMS was bilaterally symmetrical, indicating that MST did not interfere with the function of the corticospinal tract neurones. The patient showed fair motor recovery and good seizure control after the operation. These results of TMS studies demonstrated the remarkable effectiveness of MST not only on intractable seizure but also on abnormal motor cortical organization and hyperexcitability in cortical dysgenesis.

Cerebral Cortex↗

Alcohol consumption and frontal lobe shrinkage: study of 1432 non-alcoholic subjects.

OBJECTIVES: To evaluate the influences of chronic alcohol consumption on brain volume among social drinkers, as it is well known that alcohol misusers have a high risk of brain shrinkage. METHODS: Frontal lobe volumes on MRI were compared with the current alcohol habits of consecutive 1432 non-alcoholic subjects. RESULTS: After adjusting for other variables, age was found to be the most powerful promoting factor for the shrinkage with a odds ratio of 2.8 (95% confidence interval (95% CI) 1.23-3.06) for each 10 years of age. Regarding alcohol habit, 667 of the subjects were abstainers, and 157, 362, and 246 of the subjects were light (average 88.2 g ethanol/week), moderate (181.2 g/week), and heavy (418.1 g/week) drinkers, respectively. Moderate alcohol consumption did not increase the incidence of frontal lobe shrinkage (odds ratio 0.98; 95% CI 0.73-1.33), whereas heavy drinkers were at a higher risk compared with abstainers (1.80; 1.32-2.46). The contributory rate of alcohol consumption for frontal lobe shrinkage was 11.3%. CONCLUSION: The brain tends to shrink physiologically with age. Heavy alcohol consumption seems to exaggerate this shrinkage in social drinkers. Moderate alcohol consumption does not seem to affect brain volume.

Adult↗

Preferential recruitment of ataxin-3 independent of expanded polyglutamine: an immunohistochemical study on Marinesco bodies.

In an immunohistochemical study of Marinesco bodies--a neuronal intranuclear inclusion often seen in neurons of the substantia nigra of patients with hepatic encephalopathy--it was shown that one of the polyglutamine proteins, ataxin-3, is preferentially recruited into this inclusion, whereas other polyglutamine proteins (ataxin-2 and TATA box-binding protein) are not. This suggests that recruitment of each of the polyglutamine proteins may be differently regulated. Because this nuclear inclusion is thought to be formed in response to cellular stress, as occurs in hepatic encephalopathy, even in the absence of an expanded CAG/polyglutamine repeat, recruitment of ataxin-3 and ubiquitin into Marinesco bodies may represent a cellular response to noxious external stimuli unrelated to expanded CAG/polyglutamine.

Aged↗

Alternating paroxysmal hemiballism-hemichorea in bilateral internal carotid artery stenosis.

A 72-year-old man presented with paroxysmal and transient involuntary movements, or "limb shaking". The attacks occurred alternately from one side of the body to the other and ceased spontaneously. Surface EMG study showed synchronous grouping discharges in multiple limb muscles, being compatible with hemiballism-hemichorea. Cerebral angiography demonstrated marked stenosis of the bilateral internal carotid arteries. Bilateral carotid endarterectomy led to complete disappearance of the involuntary movements. Alternating paroxysmal hemiballismhemichorea might be a transient ischemic attack, and alternating striatal dysfunction induced by cerebral hemodynamic or microembolic ischemia probably plays a central role in the occurrence of such involuntary movements.

Aged↗

[Clinical features of autosomal dominant spinocerebellar ataxias genetically unclassified into any known triplet-repeat diseases].

To clarify the clinical features of genetically unclassified autosomal dominant spinocerebellar ataxias (AD-SCAs) treated in our hospital, we retrospectively analyzed the clinical findings of patients who could not be molecularly classified into SCA types 1 through 3, 6 through 8, 12 and dentato-rubro-pallido-luysian atrophy (DRPLA). The clinical findings of 19 patients from 15 different families which form 14 percent of all patients with different types of AD-SCAs (136 patients, 105 families) were collected. Based on these, 17 patients from 13 families showed late-onset (mean age at onset: 46 years old) and slowly progressive truncal and limb ataxias of cerebellar origin. Some of them showed gaze-evoked nystagmus, increased deep reflexes without Babinski sign, tremor, mildly decreased vibration sense and mild rectourinary disturbances. All but one were still ambulatory after 15 years of their mean disease duration. An earlier disease onset in successive generations was observed in 8 families. Brain MRIs revealed cerebellar atrophy predominantly in the anterior vermis in all the patients and mild brainstem atrophy in only 3 patients. Although the clinical phenotype manifested by most of the genetically unclassified AD-SCAs is similar to that of SCA6, whether the phenotype is caused by expansion of triplet repeats or some mutations in a single gene or different mutations in various genes is still unclarified.

Adult↗

[A case of visual agnosia for picture with right occipital lobe infarction].

We report a 74-year-old right-handed man with visual agnosia for picture due to right occipital lobe infarction. The patient had a remarkable impairment in visual recognition for standardized pictures made by Snodgrass and Vanderwart, in addition to left hemianopsia, left visuospatial neglect, and mild prosopagnosia. The visual agnosia for picture was generally recognized as a mild-type of the visual object agnosia, which was extremely rare in the patients with right occipital lesion. We discussed the mechanism of the visual agnosia in the right occipital lesion. Therefore, it raises the possibility that the broad impairment of the right occipital artery territory including parahippocampal gyrus as well as corpus callosum can cause the visual agnosia for picture.

Aged↗

[Serum cytokine levels response to cardiac surgery with cardiopulmonary bypass].

The response of tumor necrosis factor alpha (TNF alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), interleukin-1 receptor antagonist (IL-1ra), macrophage colony stimulating factor (MCSF), white blood cell (WBC), platelet (Plt), lactic acid (LAC) to cardiopulmnary bypass (CPB) were studied until 48 hours after aortic declamping in 11 patients who underwent elective CABG (n = 4), mitral valve plasty or replacement with modified maze procedure (n = 5), and both procedures (n = 2). The highest levels of the cytokines IL-6, IL-8, IL-10, and IL-1ra were observed after the removal of the cross clamp. These cytokines just after the aortic declamping are likely to be occurred not only by an interaction of the blood components with the artificial surfaces, but also by ischemia-reperfusion injury upon discontinuation of the aortic clamping. MCSF increased gradually in the late post-CPB phase and reached a peak at 48 hr after aortic declamping. MCSF may play an important role in regulating hematopoiesis on the postoperative days 1 and 2 in patients. In conclusion, the therapy based on the kinetics of these cytokines would be useful for patients undergoing CPB.

Aged↗

Mitral valve plasty for mitral regurgitation after blunt chest trauma.

A 21 year-old woman was admitted to our hospital because of chest and back pain after blunt chest trauma. On admission, consciousness was clear and a physical examination showed labored breathing. Her vital signs were stable, but her breathing gradually worsened, and artificial respiration was started. The chest roentgenogram and a subsequent chest computed tomographic scans revealed contusions, hemothorax of the left lung and multiple rib fractures. A transthoracic echocardiography (TTE) revealed normal left ventricular wall motion and mild mitral regurgitation (MR). TTE was carried out repeatedly, and revealed gradually progressive MR and prolapse of the posterior medial leaflet, although there was no congestive heart failure. After her general condition had recovered, surgery was performed. Intraoperative transesophageal echocardiography (TEE) revealed torn chordae at the posterior medial leaflet. The leaflet where the chorda was torn was cut and plicated, and posterior mitral annuloplasty was performed using a prosthetic ring. One month later following discharge, the MR had disappeared on TTE.

Accidents, Traffic↗

Enhanced motor cortical excitability in the unaffected hemisphere after hemispherectomy.

We evaluated motor cortical excitability of the unaffected hemisphere in three patients with intractable epilepsy who underwent hemispherectomy, using transcranial magnetic stimulation (TMS) and PET. TMS of the unaffected hemisphere evoked motor responses not only in the contralateral muscles but also in the ipsilateral ones in all the patients. A PET study in one patient showed activation of the unaffected motor cortex by movement of either arm. All of these responses were enhanced after the hemispherectomy, probably due to motor cortical disinhibition by transection of the corpus callosum. The PET study also showed postoperative activation of the premotor area of the unaffected hemisphere. These phenomena indicate posthemispherectomy neuroplastic reorganization leading to preservation of the motor function after the operation.

Adult↗

Aberrant splicing of human Cu/Zn superoxide dismutase (SOD1) RNA transcripts.

Two abnormal SOD1 mRNAs, exon 2-skipping and exon 2 and 3-skipping species, were identified from occipital brain tissue of sporadic amyotrophic lateral sclerosis (ALS) patients carrying no mutations in the SOD1 gene. Both transcripts were ubiquitously expressed in non-neuronal as well as neuronal tissues from a subject without neurological diseases. The expression pattern did not show disease specificity or lesional selectivity associated with ALS. Transient expression studies revealed weak expression of the proteins derived from the exon 2-skipping SOD1 cDNA in a cell-free translation system but not in cells. The putative abnormal SOD1 protein may accumulate and exert toxic effects on motor neurons in ALS when the proteolytic system is disturbed by aging or some causal factors.

Adolescent↗

MAPK upstream kinase (MUK)-binding inhibitory protein, a negative regulator of MUK/dual leucine zipper-bearing kinase/leucine zipper protein kinase.

Mitogen-activated protein kinase upstream kinase/dual leucine zipper-bearing kinase/leucine-zipper protein kinase (MUK/DLK/ZPK) is a MAPKKK class protein kinase that induces JNK/SAPK activation. We report here a protein named MBIP that binds to MUK/DLK/ZPK. MUK-binding inhibitory protein (MBIP) contains two tandemly orientated leucine-zipper-like motifs with a cluster of basic amino acids located between the two motifs. MBIP interacts with one of the two leucine-zipper-like motifs of MUK/DLK/ZPK and inhibits the activity of MUK/DLK/ZPK to induce JNK/SAPK activation. Notably, no similar effect was observed with another JNK/SAPK-inducing MAPKKK, COT/Tpl-2, showing the specificity of MBIP action. Furthermore, the overexpression of MBIP partially inhibits the activation of JNK by 0.3 m sorbitol in 293T cells. Taken together, these observations indicate that MBIP can function as a regulator of MUK/DLK/ZPK, a finding that may provide a clue to understanding the molecular mechanism of JNK/SAPK activation by hyperosmotic stress.

3-Phosphoinositide-Dependent Protein Kinases↗

Loss of the muscle silent period evoked by transcranial magnetic stimulation of the motor cortex in patients with cervical cord lesions.

The silent period following motor evoked potentials in small hand muscles after transcranial magnetic stimulation (TMS) of the human motor cortex is considered to be cortical origin. The authors report three patients with cervical spinal cord lesions who showed loss of the cortical silent period (CSP) after TMS. One patient had traumatic cervical cord injury, and the other two patients had cervical spondylosis. All the patients had cervical cord compression on magnetic resonance imaging. TMS study showed loss of the CSP in both the hand and foot muscles in two patients and only in the foot muscle in one patient. Paired TMS study in one patient with pseudoathetotic hands showed reduced inhibition within the motor cortex. The hand weakness or interrupted sensory afferents might have caused motor cortical reorganization or hyperexcitability, leading to the loss of the CSP.

Adult↗

Autonomic failure in ALS with a novel SOD1 gene mutation.

The authors report a patient with ALS and a novel SOD1 gene mutation who was in the totally locked-in state and developed autonomic failure followed by sudden cardiac arrest. A neuropathologic study showed widespread multisystem degeneration, including involvement of the autonomic nuclei in the medulla and spinal cord. SOD1 gene analysis detected a missense mutation of V118L in exon 4. These findings show notable phenotypic heterogeneity for SOD1-associated ALS.

Adult↗

Differential clinical significance of alpha(v)Beta(3) expression in primary lesions of acral lentiginous melanoma and of other melanoma histotypes.

Despite its potential clinical relevance, alpha(v)beta(3) expression has been analyzed only in a limited number of melanoma lesions, mostly nodular melanoma (NM) and superficial spreading melanoma (SSM). Therefore, in the present study, we have correlated alpha(v)beta(3) expression in 33 acral lentiginous melanomas (ALMs), 6 lentigo maligna melanomas, 7 mucosal melanomas, 12 NMs and 9 SSMs with their antigenic profile, with their histo-pathological characteristics and with the clinical course of the disease. Furthermore, we have compared alpha(v)beta(3) expression in ALM lesions with that in NM and SSM lesions since this information helps to clarify the relationship of the latter 2 histotypes with ALM. Such a relationship is uncertain since ALM has a clinical course similar to that of NM and SSM despite different antigenic profiles and biological characteristics. The level of alpha(v)beta(3) expression in primary lesions was not correlated with that of high-m. w. melanoma-associated antigen and intercellular adhesion molecule-1, with lesion thickness and with disease recurrence in ALM but was significantly correlated with these 4 parameters in the other melanoma histotypes analyzed. Therefore, alpha(v)beta(3) expression appears to have a differential clinical significance in ALM and in the other histotypes of melanoma we have analyzed since it appears to play a significant role in the progression of the disease only in non-ALM histotypes.

Adult↗