The history of the Japanese Society for Neuro-infectious Diseases: Foundation, objectives, and legacy.

The Japanese Research Group for Neuro-infectious Diseases was founded in August 1996, and by 2004 it had evolved into the Japanese Society for Neuro-infectious Diseases. The Society focuses on neuroinfectious conditions (e.g., encephalitis/encephalopathy, myelitis, and meningitis), providing a venue for academic presentations and exchanges. Clinical guidelines for major neurological infectious diseases are also published by the Society, in order to meet the social demands of each era. Although the threat of herpes simplex encephalitis has declined due to acyclovir's introduction, the frequency of encephalitis or peripheral neuropathy caused by varicella-zoster virus is increasing. In Japan, prion disease, human T-cell leukemia virus-1 (HTLV-1)-associated myelopathy (HAM), subacute sclerosing panencephalitis (SSPE), and progressive multifocal leukoencephalopathy (PML) are designated as intractable diseases. The incidence of prion disease is 1.8/1,000,000 individuals, with the sporadic type accounting for 80%. Prion disease is fatal, and effective medications are awaited. HAM's prevalence is ~3/100,000 individuals, with a male-to-female ratio of 1:2-3. HAM is common in western Japan, including Kyushu and Okinawa. The prevalence of PML is rising with the spread of both immunosuppressive therapy for transplantation and treatment for multiple sclerosis. From late 2019 through 2020, the world faced a global outbreak of coronavirus disease 2019 (COVID-19) due to virus mutations, and the threat of new mutations persists. Close attention should be paid to the emergence of new neurological infections that could arise from abnormal weather patterns and/or a decline in immune function due to aging.

Herpes zoster peripheral nerve complications: Their pathophysiology in spinal ganglia and nerve roots.

Varicella zoster virus (VZV) causes chickenpox at the primary infection and then becomes latent in the spinal dorsal root ganglia; VZV can reactivate with aging, immunosuppression, stress, and other factors, occurring as herpes zoster (HZ) at 1-2 skin segments. HZ peripheral nerve complications caused by VZV reactivation include Hunt syndrome, segmental HZ paresis, post-herpetic neuralgia, and Guillain-Barré syndrome (GBS). We have encountered the rare HZ complications of upper-limb paresis, myeloradiculitis, and polyradiculoneuritis: an adult woman with upper-limb paresis consistent with the nerve root on segments above the thoracic HZ dermatome; another woman exhibiting ascending myeloradiculitis originating at the Th11-12 roots; an elderly woman with ascending VZV polyradiculoneuritis resembling GBS; an adult with VZV quadriplegia with disseminated HZ; and an elderly patient with VZV-associated polyradiculoneuritis. The three polyradiculoneuritis cases may be a new subtype of HZ peripheral neuropathy, but the pathophysiology for these HZ peripheral nerve complications unrelated to HZ dermatomes is unclear. We analyzed host factors, skin lesions, neurological and virological findings, and MRI results including 3D NerveVIEW in 15 Japanese patients treated at our facility for HZ peripheral neuropathy, including six differing from the HZ dermatome. Based on the clinical findings including MRI results of spinal ganglia and roots, we identified four possible routes for the patterns of VZV spread: (i) ascending spinal roots, (ii) ascending spinal cord, (iii) polyradiculopathy, and (iv) intrathecal spread. The incidence of HZ is increasing with the aging of many populations, and clinicians should be aware of these HZ neuropathies.

Re-survey of 16 Japanese patients with advanced-stage hereditary motor sensory neuropathy with proximal dominant involvement (HMSN-P): Painful muscle cramps for early diagnosis.

Hereditary motor and sensory neuropathy with proximal dominant involvement (HMSN-P) is an intractable neurological disease with autosomal dominant inheritance, four-limb weakness, sensory impairment, and a slowly progressive course. HMSN-P patients develop four-limb paralysis at the advanced-stage, as in amyotrophic lateral sclerosis (ALS). There is a natural 20- to 30-year course from initial painful muscle cramps and four-limb paralysis to respiratory dysfunction. A delay in the diagnosis of HMSN-P occurs due to the 20- to 30-year span from the initial symptom(s) to typical quadriplegia. Its early diagnosis is important, but the involvement of painful muscle cramps as an early symptom has not been clear. Following our earlier survey, we conducted a re-survey focusing on painful muscle cramps, assistive-device use, and hope for specific therapies in 16 Japanese patients with advanced-stage HMSN-P. Fifteen patients presented painful muscle cramps as the initial symptom, and muscle cramps in the lower abdomen including the flank were described by 10 of the patients. The presence of painful muscle cramps including those in the abdominal region may be a clue for the early diagnosis of HMSN-P. Painful abdominal cramps have not described in related diseases, e.g., ALS, spinal muscular atrophy, and Charcot-Marie-Tooth disease. Recent patient-welfare improvements and advances in assistive devices including robot-suit assistive limbs are delaying the terminal state of HMSN-P. Regarding specific therapies for HMSN-P, many patients choose both nucleic acid medicine and the application of induced pluripotent stem cells as a specific therapy for HMSN-P.

Reduction of the alcohol-stimulative taste of Japanese pot-distilled spirits.

The Japanese traditional pot-distilled spirit shochu has various tastes that are produced by variations in the manufacturing processes. In this study, an alcohol-stimulative taste was organoleptically evaluated using shochu samples, and the chemical components and proton nuclear magnetic resonance (1H NMR) spectra were measured. In some shochu samples, the alcohol-stimulative taste was weaker than that of the standard 15% (v/v) EtOH-H2O mixture, and the water-ethanol hydrogen-bonding structure was stronger compared to a water-ethanol solution. However, some shochu samples filtered with ion-exchange resin had a strong alcohol-stimulative taste comparable to that of the standard 15% (v/v) EtOH-H2O mixture, and the hydrogen-bonding structure was found to be similar to that of the water-ethanol solution. We also investigated the effect of MgCl2 on reducing the alcohol-stimulative taste, and it was observed most strongly with in shochu samples filtered with ion-exchange resin. The change in chemical shift values of the 1H NMR spectra was also the largest in ion-exchange resin filtered shochu samples. The sensory reduction in the alcohol-stimulative taste could be enhanced by the strengthening of the water-ethanol hydrogen-bonding structure. Shochu samples contained many components in larger quantities compared to vodkas. It was found that MgCl2 could reduce the alcohol-stimulative taste of shochu samples. Some salts, such as MgCl2, can be introduced into spirits through the water used to dilute the ethanol content before bottling the products. Our results indicated that some components, such as MgCl2, present in water used can reduce the alcohol-stimulative taste of different spirits produced worldwide.

Varicella zoster virus associated-polyradiculoneuritis in an elderly woman: A new subtype of varicella zoster virus neuropathy.

An 82-year-old Japanese woman without underlying disease was admitted to our hospital 3 days after she noticed lower-limb weakness. At presentation, she had lower-leg motor paralysis with mild upper-limb paresis and left Ramsay Hunt syndrome. Cerebrospinal fluid (CSF) findings revealed moderate pleocytosis. A polymerase chain reaction for varicella zoster virus (VZV) DNA in CSF was positive. MRI using 3D Nerve-VIEW (Philips) and contrast T1 images showed high-intensity lesions on the L2-5 and S1-2 spinal roots. A new subtype of VZV-associated polyradiculoneuritis was diagnosed in this patient. We provide the case details and compare three similar reported cases.

[Survey of patients with advanced-stage Okinawa-type neurogenic muscular atrophy (hereditary motor and sensory neuropathy with proximal dominant involvement: HMSN-P)].

We conducted a survey of 16 Japanese patients (9 males, 7 females) aged 48-70 years in the advanced-stage Okinawa-type neurogenic muscular atrophy (i.e. hereditary motor and sensory neuropathy with proximal dominant involvement: HMSN-P) by a questionnaire asking the patients' disease name notification, acceptance, and expectations for treatment. In amyotrophic lateral sclerosis (ALS), since symptoms such as four-limb motor weakness and respiratory disorder are serious, patients are notified of the disease name at each progression stage. Individuals with HMSN-P exhibit ALS-like severe motor paralysis, but HMSN-P shows autosomal dominant inheritance, and progresses slowly (over >30 years). Many of the present patients who had one parent with the disease were able to predict what their diagnosis would be. However, several patients stated that they could not sleep for several months due to the shock of the diagnosis and their concern about how to explain to their children that the disease is hereditary. All patients in the advanced stage of HMSN-P progress to severe proximal dominant quadriplegia and ultimately need auxiliary tools such as a wheelchair. New developments toward a specific HMSN-P treatment are expected, with methods such as nucleic acid medicine.

The identified clinical features of Parkinson's disease in homo-, heterozygous and digenic variants of PINK1.

To investigate the prevalence and genotype-phenotype correlations of phosphatase and tensin homolog induced putative kinase 1 (PINK1) variants in Parkinson's disease (PD) patients, we analyzed 1700 patients (842 familial PD and 858 sporadic PD patients from Japanese origin). We screened the entire exon and exon-intron boundaries of PINK1 using Sanger sequencing and target sequencing by Ion torrent system. We identified 30 patients with heterozygous variants, 3 with homozygous variants, and 3 with digenic variants of PINK1-PRKN. Patients with homozygous variants presented a significantly younger age at onset than those with heterozygous variants. The allele frequency of heterozygous variants in patients with age at onset at 50 years and younger with familial PD and sporadic PD showed no differences. [123I]meta-iodobenzylguanidine (MIBG) myocardial scintigraphy indicated that half of patients harboring PINK1 heterozygous variants showed a decreased heart to mediastinum ratio (12/23). Our findings emphasize the importance of PINK1 variants for the onset of PD in patients with age at onset at 50 years and younger and the broad spectrum of clinical symptoms in patients with PINK1 variants.

Effects of solutes on the alcohol-stimulative taste of vodkas.

Quantitative analyses of chemical components and sensory tests were carried out on vodka samples to test for stimulative taste of ethanol. Proton nuclear magnetic resonance (1H NMR) spectra of the vodkas were measured with 600 MHz NMR. The effects of salts on the alcohol-stimulative taste were investigated for 15% (v/v) EtOH-H2O solution. 1H NMR spectroscopy results showed that a magnesium salt could reduce the stimulative taste of ethanol organoleptically and, at the same time, strengthen the hydrogen-bonding structure of water-ethanol, although the effect of the magnesium could not be clarified quantitatively in the products of vodka. It was also suggested that a change in the water-ethanol hydrogen-bonding structure could lead to a reduction in the stimulative taste of ethanol in vodka.

[Herpes zoster duplex associated with Ramsay Hunt syndrome and cervical zoster paresis. A case report].

A 63-year-old Japanese female in an immunocompetent state developed right Ramsay Hunt syndrome and left shoulder pain, and left upper limb motor paresis with herpes zoster (HZ) duplex in the right auricle and left shoulder regions. With her Ramsay Hunt syndrome, neural deafness, tinnitus and vestibular symptoms were observed, and she lacked facial nerve palsy. Cerebrospinal fluid (CSF) findings revealed an increase in lymphocytes (21 cells/µl) and protein content (29 mg/dl), and polymerase chain reaction for varicella-zoster virus DNA in CSF was negative. Cervical root MRI using 3D Nerve VIEW (Philips) imaging showed high-intensity lesions on the C5-C8 spinal roots with contrast enhancements. No abnormalities were observed in the median or ulnar motor sensory nerve conduction velocity conduction studies including the F wave. PubMed search revealed no report of a patient with this profile, and to the best of our knowledge HZ duplex with concomitant neurological impairments has not been reported. We compare our present case with several similar cases from the literature.

[A case of polyradiculoneuritis associated with disseminated herpes zoster].

A 34-year-old man developed right-dominant lower limb paraplegia, and then upper limb paresis with radicular pain following disseminated herpes zoster (HZ) in his right forehead, back of the trunk, and lumbar and right lower limb regions. Cerebrospinal fluid (CSF) findings revealed an increase in lymphocytes (32 cells/µl) and protein content (50 mg/dl), and polymerase chain reaction (PCR) for varicella-zoster virus (VZV) DNA was negative in CSF, but VZV antigen was positive in the patient's vesicle smear. Lumbar root MRI using 3D Nerve VIEW (Philips) imaging showed high-intensity lesions on the L2-L5 spinal roots with contrast enhancements, and cervical MRI showed similar findings on both sides at the C4-Th1. Peripheral nerve conduction study revealed prolonged distal latency to 4.9 ms, decreased MCV to 38 m/s, and complete loss of F-wave was seen in the right peroneal nerve study. Minimal F-wave latency was prolonged in the right tibial nerve. Thus, the patient was diagnosed with VZV polyradiculoneuritis caused by disseminated HZ. Regarding the possible pathogenesis of polyradiculoneuritis in this patient with disseminated HZ, we speculate that VZV reached by retrograde transmission from the involved peripheral nerves to the spinal ganglia, which, then, produced polyradiculoneuritis.

[Probable rheumatoid meningitis complicated by cryptococcal meningitis: A case report].

We report a case of rheumatoid meningitis complicated with cryptococcal meningitis in a 59-year-old female with rheumatoid arthritis. Migraine symptoms were followed by abnormal behavior, and the patient was admitted with fever and headache. On admission, her cerebrospinal fluid (CSF) contained 115 cells/µl, a protein content of 95 mg/dl, and a sugar level of 47 mg/dl; Her serum anti-cyclic citrullinated peptide (CCP) antibody value was high (174 U/ml), and a brain MRI showed enhanced gadolinium lesions in the cerebral/cerebellar pia mater and subarachnoid space, etc. Probable rheumatoid meningitis was clinically diagnosed, and a prednisolone (PSL) pulse was started. Several days later, a CSF culture test was positive for Cryptococcus neoformans, and the antigen titer was 128-fold. Liposomal-amphotericin B (L-AMB) was started for cryptococcal meningitis, combined with three PSL pulses for rheumatoid meningitis. After about 4 weeks, the number of CSF cells and anti-CCP antibodies decreased rapidly. At 2 months after the onset, the meningitis recurred. The MRI contrast lesions reappeared, and the CSF cells increased to 24/µl. Serum and CSF anti-CCP antibodies increased at the time of recurrence, but the cryptococcal antigen titer decreased. Thus, we concluded that the rheumatoid meningitis mainly involved the pathogenesis of both types of meningitis. The number of PSL pulses was limited to four. Post-perioral therapy was avoided. Methotrexate was continued for the rheumatoid meningitis, fluconazole was continued for the cryptococcal meningitis, and neither type of meningitis has recurred.

[Varicella-zoster virus-associated polyradiculoneuritis with concomitant herpes zoster eruption: a case report].

A 76-year-old Japanese female who was treated with long-term use of prednisolone at 10 mg/day for interstitial pneumonia developed acute right-dominant lower limb paralysis and then upper limb paralysis with herpes zoster eruptions on the right C7-Th1 dermatomes. On admission, right predominant quadriplegia was observed with sensory symptoms; Hughes functional grade was level 4; the hand grip power was right, 0, and left, 7 kg, the deep tendon reflexes were abolished throughout without pathologic reflexes. Twenty days after the onset of the symptoms, the cerebrospinal fluid (CSF) revealed mild increases of lymphocytes (13 cells/µl) and protein content (73 mg/dl). Varicella-zoster virus (VZV) PCR was negative in the CSF, but an enzyme immunoassay for VZV was positive in her serum and CSF, and the high titers were prolonged. Peripheral nerve conduction and F wave studies suggested right-dominant demyelinating polyradiculoneuropathy. A T1-weighted MR contrast image exhibited right-dominant high-intensity lesions on the C7-Th1 spinal roots and similar lesions on the L4-5 spinal roots. We compared with several similar cases from the literature and proposed that VZV itself involves the pathogenesis of the polyradiculoneuritis in immunocompromised hosts.

[A case of elderly-onset herpes simplex encephalitis in an 89-year-old woman, who recovered with acyclovir therapy, showed relapse 2 months later, and died].

The number of case reports on elderly-onset herpes simplex encephalitis (HSE) has been increasing. We encountered the case of an 89-year-old woman with HSE, who was probably one of the oldest-onset patients in Japan. She was a bed patient with underlying diseases of old cerebral infarction and cholangitis. These conditions might be risk factors for the onset of HSE. Concerning HSE among the elderly, it is important to pay attention to underlying diseases that weaken their immunity. Although we delayed in diagnosing her case and started treatment 1 month after convulsions appeared, she completely recovered with intravenous acyclovir (ACV) therapy. However, relapse occurred 2 months after the therapy ended. We treated her again with intravenous ACV but she died without improvement. ACV, which was initially effective, was ineffective at relapse. Cases of ACV-resistant herpes simplex virus (HSV) infection have been reported in immunodeficient patients. The immune system of elderly patients is sometimes too weak to suppress the mutation of the virus. In this case, the HSV may have become resistant to ACV. Therefore, the possibility of ACV resistance should be considerd in HSE relapse in the elderly population.

Indigestible dextrin is an excellent inducer for α-amylase, α-glucosidase and glucoamylase production in a submerged culture of Aspergillus oryzae.

α-Amylase activities of Aspergillus oryzae grown on dextrin or indigestible dextrin were 7·8 and 27·7 U ml(-1), respectively. Glucoamylase activities of the cultures grown on dextrin or indigestible dextrin were 5·4 and 301 mU ml(-1), respectively. The specific glucoamylase production rate in indigestible dextrin batch culture reached 1·35 U g DW(-1) h(-1). In contrast, biomass concentration of A. oryzae in indigestible dextrin culture was 35% of that in dextrin culture. Thus, the culture method using indigestible dextrin has the potential to improve amylolytic enzyme production and fungal fermentation broth rheology.

Production of multiple extracellular enzyme activities by novel submerged culture of Aspergillus kawachii for ethanol production from raw cassava flour.

Cassava is a starch-containing root crop that is widely used as a raw material in a variety of industrial applications, most recently in the production of fuel ethanol. In the present study, ethanol production from raw (uncooked) cassava flour by simultaneous saccharification and fermentation (SSF) using a preparation consisting of multiple enzyme activities from Aspergillus kawachii FS005 was investigated. The multi-activity preparation was obtained from a novel submerged fermentation broth of A. kawachii FS005 grown on unmilled crude barley as a carbon source. The preparation was found to consist of glucoamylase, acid-stable α-amylase, acid carboxypeptidase, acid protease, cellulase and xylanase activities, and exhibited glucose and free amino nitrogen (FAN) production rates of 37.7 and 118.7 mg/l/h, respectively, during A. kawachii FS005-mediated saccharification of uncooked raw cassava flour. Ethanol production from 18.2% (w/v) dry uncooked solids of raw cassava flour by SSF with the multi-activity enzyme preparation yielded 9.0% (v/v) of ethanol and 92.3% fermentation efficiency. A feasibility study for ethanol production by SSF with a two-step mash using raw cassava flour and the multi-activity enzyme preparation manufactured on-site was verified on a pilot plant scale. The enzyme preparation obtained from the A. kawachii FS005 culture broth exhibited glucose and FAN production rates of 41.1 and 135.5 mg/l/h, respectively. SSF performed in a mash volume of about 1,612 l containing 20.6% (w/v) dry raw cassava solids and 106 l of on-site manufactured A. kawachii FS005 culture broth yielded 10.3% (v/v) ethanol and a fermentation efficiency of 92.7%.

Indigestible dextrin stimulates glucoamylase production in submerged culture of Aspergillus kawachii.

Submerged batch cultures of Aspergillus kawachii grown on indigestible dextrin were investigated for potential improvements in glucoamylase (GA) production. In flask culture, specific GA productivities per dry weight biomass using dextrin and indigestible dextrin were 11.0 and 56.1 mU/mg-DW, respectively. Indigestible dextrin was a poor substrate for enzymatic hydrolysis. Rates of glucose formation from dextrin and indigestible dextrin by enzymatic hydrolysis were 0.477 and 0.100 mg-glucose/ml/h, respectively. For this reason, residual glucose concentrations in batch cultures grown on indigestible dextrin remained below 1.32 mg/ml where glucose-limiting conditions were easily maintained. Batch culture using indigestible dextrin had the same residual glucose profile as dextrin fed-batch culture, and nearly the same GA activity was obtained after 42.5 h of growth. However, between 42.5 and 66 h, the GA production rate of the indigestible dextrin batch culture (11.5 mU/ml/h) was higher than that of the dextrin fed-batch culture (6.5 mU/ml/h). During this period, a high amount of residual maltooligosaccharide was detected in the culture supernatant grown on indigestible dextrin. The high GA productivity observed in the indigestible dextrin batch culture may have resulted from the absence of glucose and the simultaneous presence of maltooligosaccharides throughout growth.

[Clinical characteristics of non-herpetic limbic encephalitis].

In Japan,the prevalence of non-herpetic acute limbic encephalitis (NHALE),characterized by a lack of evidence of the herpes simplex virus (HSV) genome or enzyme-linked immunosorbent assay (ELISA) antibody,has shown an upward trend. The causes of NHALE include several anti-neural antibodies related NHALE. Among them,NHALE that is characterized by the onset of abnormal behavior and presence of anti-glutamate receptor epsilon2 (GluRepsilon2) antibody is gaining attention. NHALE was identified in 1994 during a survey of herpes simplex encephalitis in Kyushu District. This disease has not been reported in individuals belonging to countries other than Japan. In this review article,3 cases of NHALE patients with positive GluRepsilon2 antibody titers and ovarian-teratoma-related anti-N-methyl-D-aspartate receptor (NMDAR) antibody-positive encephalitis are briefly described. In addition,the naming of this disease as well as its pathogenesis,clinical features, prognosis, and sequels are discussed in this report. Patients in the acute stage of NHALE frequently exhibited schizophrenic-like symptoms such as abnormal behavior, incoherence, delusions, and hallucinations followed by convulsive seizures, status epilepticus, and autonomic seizures. Mild signs of meningeal irritation were also detected. Magnetic resonance imaging (MRI) in these patients often revealed bilateral abnormalities in the limbic areas, including the hippocampus and amygdala. Examination of the cerebrospinal fluid (CSF) revealed mild pleocytosis, and sometimes, a lack of the pleocytosis. The CSF level of interferon-gamma remained unchanged, whereas that of interleukin-6 was increased. The prognostic outcome of the patients was rather favorable. Further, differential diagnosis for herpes simplex encephalitis is important in order to decide the initial treatment-antiviral drug therapy or immunological therapy. The most commonly described sequel of this condition is memory impairment; however,patients should be monitored for personality or emotional changes.

Analysis of enzyme production by submerged culture of Aspergillus oryzae using whole barley.

We have reported on high enzyme production by submerged culture of Aspergillus kawachii using barley with the husk (whole barley). To elucidate the mechanism underlying this high enzyme production, we performed a detailed analysis. Aspergillus oryzae RIB40 was submerged-cultured using whole barley and milled whole barley. Enzyme production was analyzed in terms of changes in medium components and gene expression levels. When whole barley was used, high production of glucoamylase and alpha-amylase and high gene expression levels of these enzymes were observed. Low ammonium concentrations were maintained with nitrate ion uptake continuing into the late stage using whole barley. These findings suggest that the sustainability of nitrogen metabolism is related to high enzyme production, and that a mechanism other than that associated with the conventional amylase expression system is involved in this relationship.

Cerebrospinal fluid levels of cytokines in non-herpetic acute limbic encephalitis: comparison with herpes simplex encephalitis.

BACKGROUND: Recently, non-herpetic acute limbic encephalitis (NHALE) was identified as a new subgroup of limbic encephalitis. The immunological pathophysiology of NHALE is still unclear. METHODS: We measured the concentrations of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2), IL-4, IL-6, IL-10, and soluble TNF receptor 1 (sTNFR1) in the cerebrospinal fluid (CSF) of 15 patients with NHALE and 13 with herpes simplex encephalitis (HSE) by cytometric bead array or ELISA. RESULTS: The CSF concentrations of IL-6 in patients with NHALE and IFN-gamma, IL-6, IL-10, and sTNFR1 in HSE patients were significantly higher than those of controls (p<0.001, p=0.004, p<0.001, p=0.018, and p<0.001, respectively). There were significant correlations among CSF IL-6, IL-10, and sTNFR1 levels in HSE patients. The CSF concentrations of IFN-gamma and sTNFR1 levels of patients with HSE were significantly higher than those with NHALE (p=0.001 and p=0.002, respectively). CONCLUSIONS: CSF cytokine levels in NHALE were relatively low compared with those in HSE. These results may be related to the favorable prognosis of NHALE.