Characterizing the temporal patterns of avian influenza virus introduction into Japan by migratory birds.

The objectives of the present study were to observe the temporal pattern of avian influenza virus (AIV) introduction into Japan and to determine which migratory birds play an important role in introducing AIV. In total, 19,407 fecal samples from migratory birds were collected at 52 sites between October 2008 and May 2015. Total nucleic acids extracted from the fecal samples were subjected to reverse transcription loop-mediated isothermal amplification to detect viral RNA. Species identification of host migratory birds was conducted by DNA barcoding for positive fecal samples. The total number of positive samples was 352 (prevalence, 1.8%). The highest prevalence was observed in autumn migration, and a decrease in prevalence was observed. During autumn migration, central to southern Japan showed a prevalence higher than the overall prevalence. Thus, the main AIV entry routes may involve crossing the Sea of Japan and entry through the Korean Peninsula. Species identification was successful in 221 of the 352 positive samples. Two major species sequences were identified: the Mallard/Eastern Spot-billed duck group (115 samples; 52.0%) and the Northern pintail (61 samples; 27.6%). To gain a better understanding of the ecology of AIV in Japan and the introduction pattern of highly pathogenic avian influenza viruses, information regarding AIV prevalence by species, the prevalence of hatch-year migratory birds, migration patterns and viral subtypes in fecal samples using egg inoculation and molecular-based methods in combination is required.

Severity and progression rate of cerebellar ataxia in 16q-linked autosomal dominant cerebellar ataxia (16q-ADCA) in the endemic Nagano Area of Japan.

16q22.1-linked autosomal dominant cerebellar ataxia (16q-ADCA) is a recently defined subtype of ADCA identified by a disease-specific C/T substitution in the 5' untranslated region of the puratrophin-1 gene. In Nagano, the central mountainous district of the main island of Japan, 16q-ADCA and spinocerebellar ataxia type 6 (SCA6) are the most and second most prevalent subtypes of ADCA, respectively. Both subtypes are classified into Harding's ADCA III, but little attention has been given to the differences in the severity and progression rate of cerebellar ataxia between 16q-ADCA and SCA6. We investigated the clinical severity and progression rate of cerebellar ataxia of 16q-ADCA patients using international cooperative ataxia rating scale and scale for the assessment and rating of ataxia and compared them with those of SCA6 patients. The age at onset was much higher in 16q-ADCA patients (60.1 +/- 9.8 years, n = 66) than in SCA6 patients (41.1 +/- 8.7 years, n = 35). Clinical features of 16q-ADCA were basically consistent with pure cerebellar ataxia, as well as in SCA6, but gaze-evoked nystagmus was observed less frequently in 16q-ADCA patients than in SCA6 patients. When compared at almost the same disease duration after onset, the severity of cerebellar ataxia was a little higher, and the progression rate seemed more rapid in 16q-ADCA patients than in SCA6 patients, but the differences were not significant.

Congenital fibrosis of the extraocular muscles (CFEOM) syndrome associated with progressive cerebellar ataxia.

We here report on a Japanese family with congenital fibrosis of the extraocular muscles (CFEOM) syndrome associated with slowly progressive cerebellar ataxia. The pedigree indicated autosomal dominant inheritance. All affected individuals showed a complete loss of upgaze function with ptosis, and severe or moderate restriction of downgaze function probably from the birth. Horizontal gaze function was well preserved, except for the eldest patient, who showed both eyes almost totally fixed in exotrophic position. The primary vertical and horizontal position of each eye varied from patient to patient. Aberrant eye movements were observed on attempted upgaze. They showed amblyopia and/or astigmatism, but none of them complained of diplopia. Pupillary reactions were normal, and retinal pigmentary degeneration or optic atrophy was not observed. These ophthalmological findings were consistent with the CFEOM phenotype. The two middle-aged patients, but not the two younger patients, showed slowly progressive gait ataxia with juvenile onset. Magnetic resonance images of the brain indicated cerebellar atrophy in addition to congenital hypoplasia in the cerebellar vermis. Molecular genetic analysis provided a negative linkage to the FEOM3 locus. Linkage to the FEOM1 locus could not be excluded in our family, but mutation in KIF21A, a major cause of the CFEOM1 phenotype, was not detected. We consider that this family may broaden the spectrum of the clinical features of CFEOM or the related disorders presenting with the CFEOM phenotype.

An autopsy case with adult onset type II citrullinemia showing myelopathy.

Hepatic myelopathy is a rare neurological complication in patients with chronic liver failure and most patients who suffered from this disorder were demonstrated to have portal-systemic shunt. A 31-year-old man who was diagnosed as having adult-onset type II citrullinemia (CTLN2) and had a six-year history of recurrent hepatic encephalopathy showed progressive spastic paraparesis with no involvement of sensation and sphincter function. Examinations of cerebrospinal fluid and spinal MRI were normal. He suddenly died of acute exacerbation of hepatic encephalopathy with severe brain edema. The pathology of the spinal cord disclosed a localized degeneration of both lateral columns, the lesion being more remarkable in the lower segments of the cord. These clinical and pathological findings of hepatic myelopathy have not been noted in the many patients with CTLN2 previously reported, and our patient is unique in developing hepatic myelopathy without porto-caval shunting. Thus, repeated attacks of encephalopathy with hyperammonemia might secondarily have induced the myelopathy in this patient.

A -16C>T substitution in the 5' UTR of the puratrophin-1 gene is prevalent in autosomal dominant cerebellar ataxia in Nagano.

The molecular bases of autosomal dominant cerebellar ataxia (ADCA) have been increasingly elucidated, but 17-50% of ADCA families still remain genetically undefined in Japan. In this study we investigated 67 genetically undefined ADCA families from the Nagano prefecture, and found that 63 patients from 51 families possessed the -16C>T change in the puratrophin-1 gene, which was recently found to be pathogenic for 16q22-linked ADCA. Most patients shared a common haplotype around the puratrophin-1 gene. All patients with the -16C>T change had pure cerebellar ataxia with middle-aged or later onset. Only one patient in a large, -16C>T positive family did not have this change, but still shared a narrowed haplotype with, and was clinically indistinguishable from, the other affected family members. In Nagano, 16q22-linked ADCA appears to be much more prevalent than either SCA6 or dentatorubral-pallidoluysian atrophy (DRPLA), and may explain the high frequency of spinocerebellar ataxia.

Regional features of autosomal-dominant cerebellar ataxia in Nagano: clinical and molecular genetic analysis of 86 families.

The frequency of autosomal-dominant cerebellar ataxia (ADCA) subtypes was examined in 86 unrelated families originating from Nagano prefecture. In Nagano, the prevalence of spinocerebellar degeneration (SCD) was approximately 22 per 100,000 population. Among ADCA families, SCA6 was the most prevalent subtype (16 families, 19%), followed by DRPLA (nine families, 10%), SCA3/MJD (three families, 3%), SCA1 (two families, 2%), and SCA2 (one family, 1%). No families with SCA7, SCA12, or SCA17 were detected. Compared with other districts in Japan, the prevalence of SCA3/MJD was very low in Nagano. More interestingly, the ratio of genetically undetermined ADCA families was much higher in Nagano (55 families, 65%) than in other districts in Japan. These families tended to accumulate in geographically restricted areas such as Kiso, Saku, and Ina, indicating that the founder effect might be responsible for the high frequency of ADCA in these areas. Most patients clinically showed slowly progressive pure cerebellar ataxia of late-onset (ADCA III). In the case of 36 patients from 36 genetically undetermined ADCA III families, however, no one was completely consistent with the founder allele proposed for 16q-ADCA. These results indicate that there might be genetically distinct ADCA subtypes in Nagano.

Severe generalized dystonia as a presentation of a patient with aprataxin gene mutation.

A 14-year-old girl, homozygous for an insertion mutation of aprataxin (APTX), 689 ins T, is described. She presented with severe generalized dystonia, ataxia, ocular motor apraxia, and areflexia. The dystonia of this patient suggests involvement of the basal ganglia or thalamus, along with clinical diversity in this disorder.

Successful treatment with corticosteroid in a case of Behçet's syndrome with multiple esophageal ulcerations.

A 59-year-old woman was diagnosed with incomplete type Behçet's syndrome in 1994. The patient was hospitalized with pharyngitis and fever in August 2000, and was treated using non-steroidal anti-inflammatory drugs (NSAIDs). Symptoms improved and she was discharged. After only 3 weeks, she reported swallowing disturbance due to retrosternal pain. Esophagoscopy revealed multiple shallow oval ulcerations in the middle esophagus. Colonoscopy revealed aphthous lesions in the rectum. Prednisolone (0.5 mg/kg) was initiated for treatment of esophageal involvement. Symptoms gradually improved and subsequent esophagoscopy revealed complete healing of esophageal ulcerations.

Aceruloplasminemia with juvenile-onset diabetes mellitus caused by exon skipping in the ceruloplasmin gene.

We herein report a case of aceruloplasminemia in a 27-year-old man who had a 10-year history of diabetes mellitus. The patient developed a convulsion, most likely as a result of hypoglycemia. Unexpectedly, this episode left him in a prolonged state of unconsciousness, which necessitated neurological testing and imaging. Brain MRI showed bilateral hypo-intensities in the basal ganglia and thalamus. Molecular analysis revealed a novel splicing mutation in the ceruloplasmin (CP) gene that would result in the skipping of exon 3 during transcription. This case suggests that diabetes associated with aceruloplasminemia can become manifest in the teens.

Spontaneous pneumoperitoneum: an unusual complication of systemic reactive AA amyloidosis secondary to rheumatoid arthritis.

We report a 71-year-old man with reactive AA amyloidosis secondary to rheumatoid arthritis who developed spontaneous pneumoperitoneum with intestinal pseudo-obstruction as an initial symptom. Severe deposition of amyloid in the intestinal wall was considered to play an important role in the pathogenesis of this unusual symptom. The patient has been successfully treated with total parenteral alimentation and intermediate-dose prednisolone (30 mg/day). Although pneumoperitoneum usually suggests gastrointestinal perforation requiring emergency surgery, conservative therapy should be seriously considered in amyloidosis-related cases with no associated peritonitis, since multiple vital organs are probably involved by severe amyloid deposition, thus increasing the risks of surgery.