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Kiyotaka Kohshi

    Kiyotaka Kohshi

    A very rare case of gliosarcoma with von Recklinghausen's disease is presented. A 51-year-old man was admitted to our hospital in March 1990, because of a 2-month history of personality change and left hemiparesis. Multiple neurofibroma... more
    A very rare case of gliosarcoma with von Recklinghausen's disease is presented. A 51-year-old man was admitted to our hospital in March 1990, because of a 2-month history of personality change and left hemiparesis. Multiple neurofibroma over his whole body with many café au lait spots had been present since early childhood. His mother, brothers and children also had café au lait spots. Neurological examination on admission revealed memory disturbance, left homonymous hemianopsia and left hemiparesis. CT scan showed a large lobular lesion in the right temporoparietal region. The medial hypodense part was sharply demarcated by a ring-like enhancement, while the lateral isodense part was homogeneously enhanced. MRI showed a sharply demarcated high intensity lesion with Gd-EDTA enhancement corresponding to the enhanced area on CT. Faint staining on angiography revealed that the blood supply to the tumor was predominantly dural. At surgery, the tumor was solid and highly vascular, and adhered tightly to the dura. The superficial part of the tumor was well demarcated from the brain tissue, but the demarcation was obscure in the deeper part. Histological findings showed two clearly defined neoplastic components: a gliomatous component that was stained for GFAP, and a sarcomatous component that had spindle-shaped nuclei and eosinophilic fibers. The patient underwent radiotherapy after surgery, but the tumor soon recurred. A second operation was performed, but the tumor had infiltrated into the scalp and he died 10 months after the first operation. This combination is very rare and has not been reported previously.
    A rare case of thrombosed AVM presenting temporal lobe epilepsy is reported. A 27-year old man was admitted to our hospital because of a 7-year history of temporal lobe epilepsy. He had also suffered from generalized seizure since he was... more
    A rare case of thrombosed AVM presenting temporal lobe epilepsy is reported. A 27-year old man was admitted to our hospital because of a 7-year history of temporal lobe epilepsy. He had also suffered from generalized seizure since he was 6 years old. No neurological deficit was disclosed. CT scan demonstrated a small calcified mass lesion in the left temporal lobe which was not enhanced by contrast study. Skull X - P and cerebral angiography were normal. Low intensity area on T1-weighted MR image corresponded to the high density area on CT scan. T2-weighted MR image demonstrated that peripheral low intensity area was more prominent and extensive. Conventional EEG showed focal spike discharges from the left fronto-central lead, and subdural EEG recordings showed intermittent spike discharges from the medial side of the left temporal lobe. A 5 cm temporal lobectomy was performed and a thick fibrous mass adjacent to the hippocampoamygdala complex was removed. Histopathological examination demonstrated a thrombosed AVM surrounded by gliotic neural tissue.
    We assessed the efficacy of daily sessions of home orthostatic self‐training (30 minutes per session standing against the wall without moving) in the prevention of neurocardiogenic syncope in 37 patients. Of these, 10 patients were... more
    We assessed the efficacy of daily sessions of home orthostatic self‐training (30 minutes per session standing against the wall without moving) in the prevention of neurocardiogenic syncope in 37 patients. Of these, 10 patients were instructed to perform two sessions per day, 14 were instructed to perform a single session per day, and the remaining 13 were instructed to perform one session every other day. The patients who performed one to two sessions of training per day continued to do so over a 6‐month follow‐up period, during that time none of them experienced spontaneous syncope. Only 5 of 13 patients who were instructed to train once every two days were able to continue doing so over the 6‐month follow‐up period; however, no spontaneous syncope was observed in these five patients. The remaining 8 of 13 patients could not continue their home training, and syncope or presyncope recurred in three of them during follow‐up. We conclude that one session per day of home orthostatic self‐training should be prescribed for the prevention of neurocardiogenic syncope.
    To investigate the effectiveness and the mechanisms of an orthostatic self-training program for the prevention of neurocardiogenic syncope, 28 patients were treated with an orthostatic self-training program. Syncope was induced by head-up... more
    To investigate the effectiveness and the mechanisms of an orthostatic self-training program for the prevention of neurocardiogenic syncope, 28 patients were treated with an orthostatic self-training program. Syncope was induced by head-up tilt testing (+ 80 degrees for 30 min) in all patients. The onset time of the tilt-induced syncope was 14 +/- 7 min following placement in the upright position. The orthostatic self-training program included standing against a wall without moving twice a day every day for a planned duration of up to 30 min at home. The head-up tilt response was re-evaluated after 24 +/- 6 days based on results of the self-training. In 12 of the 28 patients, the sympathovagal balance was also determined during the head-up tilt test before and after the training with power spectral analysis of heart rate variability using a maximal entropy method. Syncope was not observed in any patient after the training. Although the low frequency/high frequency ratio in the supine position was not different before and after the training, the ratio after 3 min in the upright position after the training decreased significantly compared with that before the training. High-frequency components in the supine and upright positions were not different before and after the training. We concluded that orthostatic self-training significantly improved symptoms in patients with tilt-induced neurocardiogenic syncope. Decreased sympathetic activity in the early stage of the upright position period may play an important role in the mechanisms of this therapy.
    Decompression illness (DCI) is well known in compressed-air diving but has been considered anecdotal in breath-hold divers. Nonetheless, reported cases and field studies of the Japanese Ama, commercial or professional breath-hold divers,... more
    Decompression illness (DCI) is well known in compressed-air diving but has been considered anecdotal in breath-hold divers. Nonetheless, reported cases and field studies of the Japanese Ama, commercial or professional breath-hold divers, support DCI as a clinical entity. Clinical characteristics of DCI in Ama divers mainly suggest neurological involvement, especially stroke-like cerebral events with sparing of the spinal cord. Female Ama divers achieving deep depths have rarely experienced a panic-like neurosis from anxiety disorders. Neuroradiological studies of Ama divers have shown symptomatic and/or asymptomatic ischaemic lesions situated in the basal ganglia, brainstem, and deep and superficial cerebral white matter, suggesting arterial insufficiency. The underlying mechanism(s) of brain damage in breath-hold diving remain to be elucidated; one of the plausible mechanisms is arterialization of venous nitrogen bubbles passing through right to left shunts in the heart or lungs. Although the treatment for DCI in Ama divers has not been specifically established, oxygen breathing should be given as soon as possible for injured divers. The strategy for prevention of diving-related disorders includes reducing extreme diving schedules, prolonging surface intervals and avoiding long periods of repetitive diving. This review discusses the clinical manifestations of diving-related disorders in Ama divers and the controversial mechanisms.
    A 49-year-old man underwent hyperbaric oxygen (HBO) therapy for the treatment of primary spinal epidural abscess. Although the epidural abscess was initially treated with antibiotic (cefozopran) for 5 days, he subsequently developed motor... more
    A 49-year-old man underwent hyperbaric oxygen (HBO) therapy for the treatment of primary spinal epidural abscess. Although the epidural abscess was initially treated with antibiotic (cefozopran) for 5 days, he subsequently developed motor weakness, paresthesia and urinary retention. MRI demonstrated spinal cord compression at the C1-C4 level. HBO therapy was added to the antibiotic regimen, and three days later we found clinical evidence of a response to treatment. Neurological symptoms were relieved 13 days after HBO therapy. This case suggests that HBO therapy is an effective therapeutic adjunct for the treatment of spinal epidural abscess.
    We report on two Japanese breath-hold divers (ama) who developed neurological disturbances following more than 3 hours of consecutive dives to 15-25 meters of seawater. Their magnetic resonance images of the brain showed multiple cerebral... more
    We report on two Japanese breath-hold divers (ama) who developed neurological disturbances following more than 3 hours of consecutive dives to 15-25 meters of seawater. Their magnetic resonance images of the brain showed multiple cerebral infarcts which were consistent with their neurological symptoms. The cerebral lesions seem to have been caused by repetitive breath-hold dives for extended periods of time. Immediate recompression is required when neurological symptoms develop after such dives.
    A survey was conducted in the northern district of Yamaguchi, Japan to determine the relationship between neurological diving accidents and risk factors among commercial breath-hold divers (Ama). A questionnaire was distributed to 381 Ama... more
    A survey was conducted in the northern district of Yamaguchi, Japan to determine the relationship between neurological diving accidents and risk factors among commercial breath-hold divers (Ama). A questionnaire was distributed to 381 Ama divers who are members of the Ama diving union. We sought information on their dive practices (depth of single dive, single dive time, surface interval, length of dive shifts, lunch break) and the presence or absence of medical problems, such as hypertension, cardiac arrhythmia, diabetic mellitus and other issues. Of the 381 Ama divers, 173 responded (45%): 29 were Funado (assisted-descent using weights) and 144 Cachido (unassisted) divers. Twelve had experienced strokelike symptoms during or after repetitive breath-hold diving; 11 were assisted and one unassisted (Funado vs. Cachido). Only two of 12 divers with neurological diving accidents had musculoskeletal symptoms. Neurological events were significantly correlated with dive depth, dive time, and surface interval; however, they were not related to medical history. Neurological diving accidents are more likely to happen among assisted Ama divers than unassisted ones. Repetitive breath-hold diving with a deep dive depth, long dive time, and short surface interval predisposes divers to decompression illness, which characteristically manifests as cerebral stroke.
    NAT1, which biotransforms many carcinogens, is genetically polymorphic. This polymorphism has been postulated as a mechanism for susceptibility differences in cancer, possibly due to NAT1 activity differences. However, the relationship... more
    NAT1, which biotransforms many carcinogens, is genetically polymorphic. This polymorphism has been postulated as a mechanism for susceptibility differences in cancer, possibly due to NAT1 activity differences. However, the relationship between NAT1 genotype and phenotype is not clear. In our study of 110 Japanese, the frequency of the NAT1*10 allele (0.53, 95% confidence interval 0.46-0.59) was higher than others have observed in Caucasians (0.16). From genotype frequency studies, 26.4% of the subjects belonged to the NAT1*10/*10 genotype, 53.6% to the NAT1*4/*10 genotype and 20% to the NAT1*4/*4 genotype. Neither NAT1*3 nor NAT1*11 genotype was seen in these subjects. In female subjects, we found higher NAT1 activity in NAT1*4/*10 subjects than in NAT1*4/*4 subjects (n = 49; 2.63 versus 2.16 nmol/min/mg protein). NAT1 activity-difference between NAT1*4/*10 and NAT1*10/*10 was not statistically significant. Thus, not only the presence of NAT1*10 allele, but also other factors are suspected of increasing NAT1 activities. After full sequencing of 10 subjects, five individuals having the highest activities and five individuals having the lowest activities, we found NAT1*18A and NAT1*18B to be in the high activity group and the low activity group, respectively. The genotypes containing these variants were heterozygous, i.e. NAT1*4/*18A and NAT1*4/*18B. Due to rare frequencies of these variants, they cannot be considered as other effective, genetic factors on NAT1 activity. Age and tobacco smoking did not affect the relationship between NAT1 genotype and phenotype.
    Repetitive breath-hold (BH) diving can lead to accumulation of nitrogen (N2) in blood and tissues, which may give rise to decompression illness (DCI). An unusual condition is "Taravana", the diving syndrome reported by Cross in the 1960s.... more
    Repetitive breath-hold (BH) diving can lead to accumulation of nitrogen (N2) in blood and tissues, which may give rise to decompression illness (DCI). An unusual condition is "Taravana", the diving syndrome reported by Cross in the 1960s. That report generated wide discussion as to whether BH diving can cause DCI. Paulev was the first person to suggest the link between DCI and BH diving. He, a submarine medical officer developed symptoms of DCI after a series of BH dives, having proceeded the dives by spending time in a hyperbaric chamber at 20 meters for 8 minutes. Recently four professional Japanese BH divers (Ama) with histories of diving accidents were reported. Magnetic resonance imaging of these divers detected cerebral infarcts localized in the watershed areas of the brain. A survey conducted on their island revealed that many Ama divers had experienced stroke-like events. A clinical feature of DCI in BH diving is that the damage is limited to the brain. Although the mechanisms of brain damage in BH diving are unclear, N2 bubbles passing through the lungs or the heart so as to become arterialized are most likely to be the etiological factor.
    E-cadherin is an epithelial cell adhesion molecule, and decreased E-cadherin expression in human prostate cancer is associated with tumor grade and advanced clinical stage. A -160... more
    E-cadherin is an epithelial cell adhesion molecule, and decreased E-cadherin expression in human prostate cancer is associated with tumor grade and advanced clinical stage. A -160 C-->A polymorphism in the promoter region of E-cadherin has been shown to decrease gene transcription. This allelic variation may be a potential genetic marker that can help identify those individuals at higher risk for invasive/metastatic disease. We studied the effect of E-cadherin gene polymorphism on prostate cancer susceptibility in a case control study of 219 prostate cancer patients and 219 male controls, to determine whether this polymorphism is a biomarker for the risk and how aggressive the disease is. The genotype frequencies in the prostate cancer group were C/C: 0.607, C/A: 0.352, A/A: 0.041, and in the control group C/C: 0.671, C/A: 0.301, A/A: 0.027. A significant difference between the two groups was not found (p = 0.34), and the adjusted OR for A/A genotype was not statistically significant (OR = 1.66, 95% CI 0.58-4.78). Subdividing prostate cancer according to tumor differentiation and stage, we found no association between E-cadherin polymorphism and poor differentiation and invasiveness of prostate cancer. These data do not support an association between the E-cadherin genotype and the occurrence or progression of prostate cancer in Japanese populations.
    To investigate the effectiveness and the mechanisms of an orthostatic self-training program for the prevention of neurocardiogenic syncope, 28 patients were treated with an orthostatic self-training program. Syncope was induced by head-up... more
    To investigate the effectiveness and the mechanisms of an orthostatic self-training program for the prevention of neurocardiogenic syncope, 28 patients were treated with an orthostatic self-training program. Syncope was induced by head-up tilt testing (+ 80 degrees for 30 min) in all patients. The onset time of the tilt-induced syncope was 14 +/- 7 min following placement in the upright position. The orthostatic self-training program included standing against a wall without moving twice a day every day for a planned duration of up to 30 min at home. The head-up tilt response was re-evaluated after 24 +/- 6 days based on results of the self-training. In 12 of the 28 patients, the sympathovagal balance was also determined during the head-up tilt test before and after the training with power spectral analysis of heart rate variability using a maximal entropy method. Syncope was not observed in any patient after the training. Although the low frequency/high frequency ratio in the supine position was not different before and after the training, the ratio after 3 min in the upright position after the training decreased significantly compared with that before the training. High-frequency components in the supine and upright positions were not different before and after the training. We concluded that orthostatic self-training significantly improved symptoms in patients with tilt-induced neurocardiogenic syncope. Decreased sympathetic activity in the early stage of the upright position period may play an important role in the mechanisms of this therapy.
    Both genetic and environmental factors are involved in the development of cancer. Oral cavity cancer has been reported to be epidemiologically associated with tobacco and alcohol consumption. We examined genetic polymorphisms of the... more
    Both genetic and environmental factors are involved in the development of cancer. Oral cavity cancer has been reported to be epidemiologically associated with tobacco and alcohol consumption. We examined genetic polymorphisms of the glutathione-S-transferase (GST) M1/T1, cytochrome P-450 (CYP) 1A1/2E1 and aldehyde dehydrogenase 2 (ALDH2) genes in 92 Japanese patients with oral cavity cancer and 147 unrelated non-cancer Japanese controls. There was a significant association between cigarette smoking and cancer risk but no significant association between alcohol consumption and cancer risk. The frequency of the GSTM1 null genotype was significantly higher in cancers (58.7%) compared with controls (46. 3%). However, there were no significant differences between controls and patients with oral cavity cancer in the polymorphisms of the GSTT1, CYP1A1, CYP2E1 and ALDH2 genes. From statistical evaluation on various combinations of genotypes, we did not observe any gene combinations associated with cancer risk. There were also no genetic polymorphisms associated with increased risk of oral cavity cancer among smokers and drinkers. These results imply that the GSTM1 null genotype has a weak correlation, but another 4 genetic polymorphisms are unlikely to be associated, with oral cavity cancer among Japanese.
    An unusual and first case of moyamoya disease of adult onset brain stem haemorrhage associated with occlusion of both vertebral arteries is reported. A 30-year-old man suddenly suffered from dyspnea, dysphagia, and left-sided hemisensory... more
    An unusual and first case of moyamoya disease of adult onset brain stem haemorrhage associated with occlusion of both vertebral arteries is reported. A 30-year-old man suddenly suffered from dyspnea, dysphagia, and left-sided hemisensory disturbance. Computed tomography and magnetic resonance imaging revealed a fresh haematoma in the left medulla oblongata and various-sized old infarcts in both parietal lobes. Cerebral angiograms disclosed occlusion of the bilateral internal carotid arteries on both sides at their intracranial portion, accompanied with the developed basal moyamoya vessels. The right vertebral artery occluded at its V2-V3 segment, in which the posterior inferior cerebellar artery was opacified via the posterior spinal artery, and the basilar artery was filled from the anterior spinal artery. The left vertebral artery was also occluded at the craniovertebral junction (V4) with collateral flow. Only one case of moyamoya disease associated with bilateral occlusion of the vertebral artery has been reported previously, and a haemorrhage into the medulla oblongata in moyamoya disease has never been described.
    We have studied how in situ arterial (PaCO2) and brain tissue PCO2 (PbCO2) responses to acetazolamide (AZ) are affected by respiratory patterns. Sixteen cats were anesthetized with ketamine. Group 1 cats (n = 7) breathed air... more
    We have studied how in situ arterial (PaCO2) and brain tissue PCO2 (PbCO2) responses to acetazolamide (AZ) are affected by respiratory patterns. Sixteen cats were anesthetized with ketamine. Group 1 cats (n = 7) breathed air spontaneously. Group 2 cats (n = 6) were paralyzed and ventilated mechanically to maintain PaCO2 at 37 +/- 1 Torr before AZ administration; the respiratory rate and depth did not change during the course of measurements. Two CO2 sensors to measure in situ PaCO2 and PbCO2 continuously were used. One was placed through a burr hole into the cerebral white matter 15 mm in depth, and another was inserted into the femoral artery. After intravenous administration of AZ (20 mg/kg), PaCO2 decreased, after a significant transient rise, and then returned gradually to the baseline in group 1, but it increased gradually and reached a new steady state in group 2. PbCO2 and the PbCO2-PaCO2 gradient increased remarkably in the two groups immediately after administration. We conclude that AZ resulted in a large increase in both PbCO2 and the PbCO2-PaCO2 gradient and that there are two distinct in situ PaCO2 responses to AZ in spontaneously breathing vs. mechanically ventilated animals. The mechanisms for these observations are discussed.

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