PubMed Health⌕ Search

Biomedical subjects

Naoki Kasahata

Publications and source records attributed to Naoki Kasahata.

6 recordsLinked to original sources
PubMed2005

[Intermediate medullary infarction: a case report].

A 68-year-old man presented with right eye pain and vertigo. Thereafter, he gradually leaned rightward, then laid down. He felt nausea and vomited. His right upper eyelid drooped and he felt dysethesia of the right hand. On neurological examination, ptosis of his right eye with slightly miotic right pupil, paresis of the right soft palate and hoarseness were noted. Arm deviation test demonstrated rightward deviation. He presented sensory ataxia of the right upper and lower extremities: finger nose test showed mild dysmetria of the right upper extremity, heel knee test demonstrated dysmetria of right lower extremity and these findings worsened when he closed his eyes. He showed mild bending of his bilateral ring and little fingers when he did rapid alternative movement. He leaned rightward when he sat and closed his eyes. Position sense of his right upper and lower extremities was decreased and sometimes he could not answer correctly when asked on which direction his finger pointed. Pinprick sensation was mildly decreased on the left side not including the face. Touch and vibration sense were normal. SEP findings on upper and lower extremity stimulation were normal. MRI of the brain showed T2 high intensity and partially T1 low intensity lesion at the right medulla (Figure). MR angiography showed no apparent lesion of major arteries such as dissection of the vertebral arteries. He complained and presented with hiccup initially. On MRI, the lesion was thought to involve the spinothalamic tract, medial lemniscus and inferior olivary nucleus. Ambiguus nucleus was in the lesion and solitary nucleus near the lesion. There is no report that seems to describe clinical features of a lesion like that in this case. Intermediate medullary infarction may present dissociated sensory disturbance like Brown-Sequard syndrome and position sensory disturbance without disturbance of vibration sense.

Aged↗
PubMed2005

[Molecular pathomechanism of distal myopathy with rimmed vacuoles].

Distal myopathy with rimmed vacuoles (DMRV) and hereditary inclusion body myopathy (HIBM) are genetically identical autosomal recessive muscle disorders caused by mutations in the GNE gene. This gene encodes a bifunctional protein with UDP-GlcNAc 2-epimerase and ManNAc kinase activities that catalyze the rate limiting step and the succeeding step, respectively, in the sialic acid biosynthetic pathway. V572L mutation is the most prevalent among Japanese DMRV patients and accounts for about 60% of mutant alleles. Clinical spectrum of DMRV/HIBM seems to be wider than previously thought in terms of both the severity of the disease and the range of affected organs. There are rare asymptomatic homozygotes with missense GNE mutations, indicating the presence of mitigating factors. Surprisingly, more than 10% of the patients had a variety of cardiac abnormalities, suggesting that skeletal muscle may not be the only organ involved. Studies on recombinant GNE demonstrate a loss-of-function nature of the missense mutations identified. Patients' cells show decreased sialylation status which can be recovered by adding GNE metabolites, such as ManNAc and NeuAc. This indicates the possibility of developing a therapy for DMRV/HIBM by giving these metabolites to patients although we have to await the model mice that are currently being produced at several laboratories.

Carbohydrate Epimerases↗
PubMed2003

Acute human T-lymphotropic virus type 1-associated myelopathy: a clinicopathologic study.

BACKGROUND: Recently, acute human T-lymphotropic virus type 1-associated myelopathy (HAM) was reported clinically without pathologic information. We report an autopsy case of acute HAM. OBJECTIVE: To report the case of a 52-year-old man with acute-onset gait disturbance followed by rapidly progressive paraplegia, who died 9 months later. RESULTS: The postmortem study showed swelling of the thoracic spinal cord. Histologically, there was inflammation and vacuolation in the white matter. CONCLUSION: We propose that these pathologic findings, mimicking tropical spastic paraparesis, may represent the characteristic pathologic features of acute HAM.

Autopsy↗