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Dive into the research topics where Hirotoshi Hamaguchi is active.

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Featured researches published by Hirotoshi Hamaguchi.


Journal of Stroke & Cerebrovascular Diseases | 2012

Clinical Features of Late-onset Poststroke Seizures

Shiho Okuda; Shin Takano; Masao Ueno; Hirotoshi Hamaguchi; Fumio Kanda

BACKGROUND Compared to the patients with early-onset seizures (ES), those with late-onset seizures (LS) have a high risk of epilepsy that is a feared complication after stroke. However, few studies have described detailed clinical features of LS in Japanese patients. METHODS To elucidate the clinical features of LS, a series of 448 stroke patients (cerebral infarction n = 286; cerebral hemorrhage n = 162) in our hospital were retrospectively examined in this study. Stroke location was determined by computed tomographic and/or magnetic resonance imaging scans. Lesion size was evaluated using the Alberta Stroke Program Early Computed Tomographic Score. We examined occurrence rate, onset time, and recurrence rate of LS. In addition, clinical features of the infarction of LS and non-LS group were compared on age, gender, laterality, location, and extent, respectively. RESULTS LS occurred in 18 patients (4.0%). Of these, 17 experienced LS within 1.5 years after stroke. While epilepsy developed in none of the patients with ES, it developed in 33% of those with LS. Patients with cortical and a larger infarction involving the middle cerebral artery had at significantly greater risk of LS (P < .05). CONCLUSIONS Patients with cortical and a larger infarction involving the middle cerebral artery should be carefully observed because of a high risk of LS.


Muscle & Nerve | 2009

Measurement of platelet-derived microparticle levels using an enzyme-linked immunosorbent assay in polymyositis and dermatomyositis patients

Toshihiko Shirafuji; Hirotoshi Hamaguchi; Masatsugu Higuchi; Fumio Kanda

Platelet‐derived microparticle (PDMP) levels were measured using an enzyme‐linked immunosorbent assay (ELISA) to elucidate the role of platelet activation in patients with polymyositis or dermatomyositis (PM/DM). PDMP levels in active PM/DM patients (median 13.3 U/ml, interquartile range 9.9–20.7 U/ml, n = 16) and those in patients undergoing treatment (12.1 U/ml, 7.4–16.7 U/ml, n = 12) were significantly higher than in controls (6.5 U/ml, 5.0–8.4 U/ml, n = 26, vs. active, P = 0.0001; vs. treatment, P = 0.004). In a paired sampling study, PDMP decreased significantly after glucocorticoid treatment (P = 0.04). PDMP in the active PM/DM patients correlated significantly with serum C‐reactive protein levels (rs = 0.67, P = 0.01). These results suggest that platelets may play an important role in the inflammatory process, and that PDMP level could be a useful marker of inflammatory activity in PM/DM patients. Muscle Nerve 39: 586–590, 2009


Journal of the Neurological Sciences | 2004

HLA typing in focal myositis

Kenji Sekiguchi; Fumio Kanda; Kenichi Oishi; Hirotoshi Hamaguchi; Kenichiro Nakazawa; Nobuya Maeda; Hiroyuki Ishihara; Kazuo Chihara

It is still controversial if idiopathic focal myositis is a part of systemic polymyositis. We present here four patients, including identical twins, with focal myositis accompanied by the same HLA typings. Gradually developing unilateral calf muscle pain was an initial symptom in all patients. Neither muscular weakness nor creatine kinase (CK) elevation was observed, while minimal inflammatory findings such as erythrocyte sedimentation rate (ESR) increase appeared in serum. Magnetic resonance imaging (MRI) revealed localized abnormalities of calf muscles. Biopsy specimen was characterized by perimysial and endomysial inflammatory infiltration consisted of T cells and macrophages and rare necrotic fibers. Corticosteroid administrations ameliorated their symptoms and signs, though recurrence occurred along with decreasing doses. HLA typings common to all patients were A2, B62, Cw3, and DQ3, whereas HLA-D DNA typings were DQB1 *0303 for two patients, and DQB1*0302 for three patients. These findings suggest that at least some focal myositis may be a new disease unit, with a common genetic background but not a part of systemic polymyositis.


International Journal of Gastrointestinal Cancer | 1999

A case of acute pancreatitis complicating salmonella enteritis

Hirotoshi Hamaguchi; Yoshinori Okabayashi; Ryoji Yoneda; Hirohisa Ueno; Seitetsu Yoon; Motoyoshi Sakaue; Masato Kasuga

SummaryWe report a case of acute pancreatitis complicating Salmonella enteritis. A 43-yr-old woman who was admitted to our department because of Salmonella enteritis developed clinical acute pancreatitis with laboratory and radiographic signs on the fourth hospital day. She was free from symptoms on the eighth hospital day, but her elevated serum amylase and lipase levels persisted for more than 2 mo. In this case, clinical acute pancreatitis was a complication of bacterial enteritis caused by Salmonella enteritidis, and it was characterized by onset a few days after the onset of enteritis and by sustained elevation of serum pancreatic enzyme levels.


Muscle & Nerve | 2009

Dropped head syndrome caused by Lambert-Eaton myasthenic syndrome.

T. Ueda; Fumio Kanda; Hiroshi Kobessho; Hirotoshi Hamaguchi; Masakatsu Motomura

A 67‐year‐old man was admitted with a 2‐year history of dropped head. Neurological examination revealed ptosis, dysarthria, neck weakness, hyporeflexia of all limbs, and autonomic failure. Electrophysiologic study showed a 400% increment response to high‐rate repetitive nerve stimulation. Serum anti‐P/Q‐voltage‐gated calcium channel antibody was positive, confirming the diagnosis of Lambert–Eaton myasthenic syndrome (LEMS). His symptoms and electrophysiological abnormalities improved with oral prednisolone following plasmapheresis. This is the first report of LEMS as a cause of dropped head syndrome. Muscle Nerve 40: 134–136, 2009


European Neurology | 2008

Elevation of Cerebrospinal Fluid Protein in Patients with Diabetes Mellitus Is Associated with Duration of Diabetes

Hiroshi Kobessho; Kenichi Oishi; Hirotoshi Hamaguchi; Fumio Kanda

We investigated the relationships between total cerebrospinal fluid (CSF) protein in diabetic patients and the clinical characteristics of diabetes mellitus. The subjects comprised 16 diabetic patients (median age = 60.5 years, range = 47–71) who were studied retrospectively. Patients with diseases known to be associated with increases in total CSF protein were excluded as far as possible. The median total CSF protein and albumin quotient in the diabetic group were 52.5 mg/dl (range = 41–84) and 6.13 × 10–3 (range = 4.0 × 10–3 to 13.1 × 10–3), respectively. These results were significantly higher than those in 28 age-matched nondiabetic patients (median = 59.0 years, range = 50–71) (p < 0.01). Duration of diabetes was associated with total CSF protein (r = 0.642, p < 0.01). If the CSF shows increased total protein in a diabetic patient who has not suffered from long-term diabetes (≧5 years), causes other than diabetes should be considered to explain increases in total CSF protein. We need to confirm the present results by studying a larger population of diabetic patients.


Journal of the Neurological Sciences | 2017

Ultrasonographic findings of proximal median neuropathy: A case series of suspected distal neuralgic amyotrophy

Yoshikatsu Noda; Kenji Sekiguchi; Hideki Tokuoka; Tetsuya Oda; Hirotoshi Hamaguchi; Fumio Kanda; Tatsushi Toda

Spontaneous anterior interosseous nerve (AIN) palsy develops following the resolution of nerve pain, which may be considered as distal neuralgic amyotrophy. NA is assumed to have a complex etiology, but an autoimmune mechanism is likely involved. However, precise assessment of the lesion is challenging. We examined five consecutive patients with suspected spontaneous AIN palsy using ultrasonography. On electromyography, all patients exhibited denervation potentials in the muscles, not only in the AIN territory, but also in the proximal median nerve territory (e.g., the flexor carpi radialis or pronator teres). Ultrasonography of the median nerve demonstrated neural swelling at the proximal side of the medial epicondyle in four patients and an hourglass-like constriction of the nerve fascicle in three patients. Four patients were diagnosed with distal neuralgic amyotrophy; of these, three received intravenous immunoglobulin administration, but only limited beneficial effect was achieved in one patient with early stage disease. One patient showed significant median nerve hypertrophy on ultrasonography and was diagnosed with neurolymphomatosis following the detection of malignant lymphoma during a systemic survey. Our experience demonstrates that ultrasonography for proximal median neuropathy presenting as AIN palsy may be useful for the accurate lesion assessment.


Internal Medicine | 2017

Validation of the R2CHADS2 and CHADS2 Scores for Predicting Post-stroke Cognitive Impairment

Kazuo Washida; Hisatomo Kowa; Hirotoshi Hamaguchi; Fumio Kanda; Tatsushi Toda

Objective Post-stroke cognitive impairment often afflicts stroke survivors and is a major obstacle both for cognitive and physical rehabilitation. Stroke risk scores [“Congestive heart failure, Hypertension, Age ≥75 years, Diabetes mellitus, Stroke” (CHADS2) and “CHADS2 + creatinine clearance <60 mL/min” (R2CHADS2)] are used to assess the future risk of cardioembolic stroke in patients with atrial fibrillation (AF). However, congestive heart failure, hypertension, aging, diabetes mellitus, stroke, and renal dysfunction are also risk factors for cognitive impairment. Methods Sixty-two patients with nonvalvular AF-induced cardioembolic stroke underwent cognitive testing, including the Japanese version of the Montreal Cognitive Assessment (MoCA-J), Mini-Mental State Examination (MMSE), and Apathy Scale. The correlations between the MoCA-J/MMSE/Apathy Scale scores and stroke risk scores were examined. Results The average CHADS2 and R2CHADS2 scores were 4.1±1.0 and 5.6±1.6, respectively. The average MoCA-J, MMSE, and Apathy Scale scores were 17.4±6.2, 22.0±5.3, and 20.0±8.9, respectively. The CHADS2 and R2CHADS2 scores were negatively correlated with the MoCA-J/MMSE and positively correlated with the Apathy Scale. The R2CHADS2 score was more sensitive to poststroke cognitive impairment than the CHADS2 score. This correlation was stronger for MoCA-J than for MMSE, as the MMSE scores were skewed toward the higher end of the range. The results for individual MoCA-J and MMSE subtests indicated that the visuoexecutive, calculation, abstraction, and remote recall functions were significantly decreased after cardioembolic stroke. Conclusion These results suggest that the R2CHADS2 and CHADS2 scores are useful for predicting post-stroke cognitive impairment.


Journal of Human Genetics | 2013

Molecular pathology of Sandhoff disease with p.Arg505Gln in HEXB: application of simulation analysis.

Naoko Yasui; Yutaka Takaoka; Hisahide Nishio; Dian Kesumapramudya Nurputra; Kenji Sekiguchi; Hirotoshi Hamaguchi; Hisatomo Kowa; Eiichi Maeda; Aki Sugano; Kenji Miura; Toshiyuki Sakaeda; Fumio Kanda; Tatsushi Toda

Sandhoff disease is a GM2 gangliosidosis caused by mutations in HEXB encoding the β-subunit of β-hexosaminidase A. β-Hexosaminidase A exists as a heterodimer consisting of α- and β-subunits, and requires a GM2 activator protein to hydrolyze GM2. To investigate the molecular pathology in an adult Sandhoff disease patient with an early disease onset, we performed mutation detection, western blot analysis and molecular simulation analysis. The patient had compound heterozygous mutations p.Arg505Gln and p.Ser341ValfsX30. Western blot analysis showed that the amount of mature form of the α- and β-subunits was markedly decreased in the patient. We then performed docking simulation analysis of the α- and β-subunits with p.Arg505Gln, the GM2AP/GM2 complex and β-hexosaminidase A, and GM2 and β-hexosaminidase A. Simulation analysis showed that p.Arg505Gln impaired each step of molecular conformation of the α- and β-subunits heterodimer, the activator protein and GM2. The results indicated that p.Ser341ValfsX30 reduced the amount of β-subunit, and that p.Arg505Gln hampered the maturation of α- and β-subunits, and hindered the catalytic ability of β-hexosaminidase A. In conclusion, various methods including simulation analysis were useful to understand the molecular pathology in Sandhoff disease.


Rinshō shinkeigaku Clinical neurology | 2015

Medial longitudinal fasciculus (MLF) syndrome in a patient with giant cell arteritis

Takeshi Uenaka; Hirotoshi Hamaguchi; Kenji Sekiguchi; Hisatomo Kowa; Fumio Kanda; Tatsushi Toda

A 76-year-old female was referred to our department because of diplopia for two months and intermittent claudication for five months. She showed medial longitudinal fasciculus (MLF) syndrome. Brain MRI (T2WI) showed multiple infarctions in the right pontine tegmentum and left paramedian midbrain. A biopsy of superficial temporal artery showed the characteristic findings of glanulomatous inflammation indicative of giant cell arteritis. We thought the mechanism of this cerebral infarction as artery to artery embolization or intracranial arteritis. Treatment with oral prednisolone (1 mg/kg/day) improved her limb claudication and normalized serum C-reactive protein level.

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Kenichi Oishi

Johns Hopkins University School of Medicine

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