Prevalence of saliva immunoglobulin A antibodies reactive with severe acute respiratory syndrome coronavirus 2 among Japanese people unexposed to the virus.

While the COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses a threat to public health as the number of cases and COVID-19-related deaths are increasing worldwide, the incidence of the virus infection is extremely low in Japan compared with many other countries. To explain this uncommon phenomenon, we investigated the prevalence of naturally occurring ("natural") antibodies, focusing on those of the secretory immunoglobulin A (sIgA) form, reactive with SARS-CoV-2 among Japanese people. One hundred and eighty healthy Japanese volunteers of a wide range of age who had been considered to be unexposed to SARS-CoV-2 participated in this study. Saliva samples and blood samples were collected from all of the 180 participants and 139 adults (aged ≥ 20 years) included therein, respectively. The determination of saliva IgA antibodies, mostly comprising sIgA antibodies, as well as serum IgA and immunoglobulin G antibodies, reactive with the receptor binding domain of the SARS-CoV-2 spike-1 subunit proteins was conducted using an enzyme-linked immunosorbent assay. The major findings were that 52.78% (95% confidence interval, 45.21%-60.25%) of the individuals who had not been exposed to SARS-CoV-2 were positive for saliva IgA antibodies with a wide range of levels between 0.002 and 3.272 ng/mL, and that there may be a negative trend in positivity for the antibodies according to age. As we had expected, a frequent occurrence of assumable "natural" sIgA antibodies reactive with SARS-CoV-2 among the studied Japanese participant population was observed.

Eyelid myoclonia with absences related to epileptic negative myoclonus.

Eyelid myoclonia with absences (EMA) is an epileptic syndrome characterised by eyelid myoclonia with or without absences, eye closure-induced paroxysms, and photosensitivity. The relationship between EMA and epileptic negative myoclonus has not previously been reported. Herein, we describe a case of a 10-year-old girl who presented with eyelid myoclonia, eye closure-induced paroxysms, and photosensitivity, which was compatible with the diagnosis of EMA. Ictal EEG depicted an eye closure-induced diffuse 3.0-4.5-Hz polyspike-and-wave complex, which was accompanied by eye fluttering (eyelid myoclonia). EMG disclosed a brief interruption (60-140 mseconds) of tonic contraction of the orbicularis oculi muscle, which was associated with the polyspike-and-wave complex on EEG. The findings led to the diagnosis of epileptic negative myoclonus. Eye closure-induced eyelid epileptic negative myoclonus, demonstrated in this patient, may be an atypical seizure type of EMA that represents an intermediate between eyelid myoclonia and epileptic negative myoclonus.

Relationship between Sedative Antihistamines and the Duration of Febrile Seizures.

Some studies have shown that sedative antihistamines prolong febrile seizure duration. Although the collective evidence is still mixed, the Japanese Society of Child Neurology released guidelines in 2015 that contraindicated the use of sedative antihistamines in patients with febrile seizure. Focused on addressing limitations of previous studies, we conducted a cross-sectional study to evaluate the relationship between febrile seizure duration and the use of sedative antihistamines. Data were collected from patients who visited St. Luke's International Hospital due to febrile seizure between August 2013 and February 2016. Patients were divided into groups based on their prescribed medications: sedative antihistamine, nonsedative antihistamine, and no antihistamine. Seizure duration was the primary outcome and was examined using multivariate analyses. Of the 426 patients included, sedative antihistamines were administered to 24 patients. The median seizure duration was approximately 3 minutes in all three groups. There was no statistical difference in the bivariate (p = 0.422) or multivariate analyses (p = 0.544). Our results do not support the relationship between sedative antihistamine use and prolonged duration of febrile seizure. These results suggest that the use of antihistamines may be considered for patients with past history of febrile seizure, when appropriate.

Relationship between salivary immunoglobulin a, lactoferrin and lysozyme flow rates and lifestyle factors in Japanese children: a cross-sectional study.

OBJECTIVE: The antimicrobial substances in saliva contribute to the maintenance of both oral health and overall health of the body. Therefore, the associations among immunoglobulin A (IgA), lactoferrin and lysozyme flow rates in the saliva of children, and their relationships with the physical attributes and lifestyle factors of children, were examined. MATERIALS AND METHODS: Saliva was collected from 90 children who visited the Kanagawa Dental University Hospital Pediatric Dentistry, and questionnaires were completed by guardians. IgA, lactoferrin and lysozyme concentrations were measured in the saliva samples using enzyme-linked immunosorbent assays (ELISAs). RESULTS: The IgA flow rate in saliva increased as age, height and weight increased. A correlation was found between lactoferrin and lysozyme flow rates. When the antimicrobial substance flow rates in the saliva were divided into two groups of 22 children each based on the highest and lowest quartiles, children with either a low or high IgA flow rate also had a high or low lactoferrin flow rate, respectively. The same pattern was observed for lactoferrin and lysozyme flow rates. CONCLUSIONS: There is a high probability that the IgA flow rate in the saliva of children reflects and corresponds to the developmental status of immune function as the child ages and increases in height and weight. The flow rates of lactoferrin and lysozyme were correlated in children. In addition, regarding lifestyle factors, the duration of sleep and lactoferrin flow rate were also related.

[Efficacy of botulinum toxin type A against cervical dystonia and muscular hypertonia in persons with severe motor and intellectual disabilities with respiratory problems and/or dysphagia].

We administered intramuscular injections of botulinum toxin type A (BTX-A) in 11 persons with cervical dystonia (CD) and muscular hypertonia (MH). All patients had severe motor and intellectual disabilities (SMID). Furthermore, in 10 patients, SMID was accompanied by respiratory problems and/or dysphagia. Three patients received night nasal intermittent positive pressure ventilation and 3 had undergone tracheotomy; 5 patients had upper respiratory problems. Because of these complications, BTX-A dose was gradually increased in those patients until the desired effect was obtained (mean last dose, 6.8 u/kg/dose). All patients were clinically assessed with the Tsui scale before treatment with BTX-A. At 1, 2, 4, and 8 weeks after BTX-A injections, responses to the injections were assessed with the Tsui scale repetitively in all patients. Significant or mild improvements in the Tsui scale scores were observed in 8 patients without any severe adverse effects. In addition, some improvements in respiration and body weight gain were observed. We observed a reduction in the number of oral medications in 10 cases. Administration of BTX-A for the treatment of SMID has numerous benefits, not all of which can be explained by Tsui scale scores. BTX-A is safe and has potential for use in the treatment of CD and MH with respiratory problems and/or dysphagia.

Reversible infantile respiratory chain deficiency: a clinical and molecular study.

OBJECTIVE: To characterize the clinical features and clarify the pathogenicity of "benign cytochrome c oxidase deficiency myopathy." METHODS: The study included 8 patients with the phenotype of this disease. Six patients underwent muscle biopsies and all the 8 underwent mitochondrial DNA analyses. To confirm the pathogenicity of the detected mitochondrial DNA mutation, we performed northern blot analysis, using muscle specimens, and blue native polyacrylamide gel electrophoresis and respiratory chain enzyme activity assay of transmitochondrial cell lines (cybrids). RESULTS: Clinical symptoms were limited to skeletal muscle and improved spontaneously in all cases; however, 2 siblings had basal ganglia lesions. In all patients, we identified a homoplasmic m.14674T>C or m.14674T>G mitochondrial transfer RNA-glutamate mutation. Northern blot analysis revealed decreased levels of mitochondrial transfer RNA-glutamate molecules. Muscle specimens and cybrids derived from patients showed decreased activity of respiratory complexes IV, and/or I, III; however, this was normal in naive myoblasts. INTERPRETATION: Identification of a novel m.14674T>G mutation in addition to m.14674T>C indicated the importance of this site for disease causation. Analyses of cybrids revealed the pathogenicity of m.14674T>C mutation, which resulted in defects of cytochrome c oxidase and multiple respiratory chain enzymes. Furthermore, patients with basal ganglia lesions provided new insights into this disease, in which only skeletal muscle was thought to be affected. Normal respiratory chain enzyme activities in naive myoblasts suggested the compensatory influence of nuclear factors, which may be a clue to understanding the mechanisms of spontaneous recovery and low penetrance in families carrying the mutation.