ハコネ エキデン オ メザシタ ヒンケツ ヨボウ タイサク

本研究では,箱根駅伝出場をめざす大学陸上競技長距離選手において,短期的な高所トレーニング合宿時の栄養調査およびHb濃度測定を実施した。ヘモグロビン濃度は8名が低下傾向を示す,いわゆる貧血症状であった。貧血傾向にある選手にヘム鉄剤を服用し,貧血の改善が可能かどうか検討した。その結果,鉄剤服用選手は,合宿直後および2週間後においてヘモグロビン濃度が改善された。また,合宿前のHb濃度は,1年生が4年生の濃度より有意に低かった。また,本合宿時における1日の鉄分摂取量は平均10.5mgであり,不足気味であった。我々は,貧血検査,鉄剤服用および栄養改善などの貧血予防対策により箱根駅伝出場を果たすことができたと推察する。The purpose of this study was to carry out a nutrition survey and also ascertain hemoglobin (Hb) concentrations at the time of a short high-altitude training camp, in the collegiate long-distance runners aiming for the finals of Hakone\u27s long-Distance relay. The hemoglobin concentrations in eight runners showed a declining trend, which is a symptom of anemia. Those runners who were in an anemia trend took hem iron and we examined whether or not the improvement of anemia was a possibility. As a result, hemoglobin concentrations in the iron recipient runners improved just after and also 2 weeks after this camp. Also, the Hb concentrations before this camp in the first year students were significantly lower than the concentrations of the fourth year student. The iron intake on this training camp averaged 10.5mg per day and was felt to be insufficient. It was considered that we were able to achieve the finals of Hakone\u27s long-distance relay by the anemia inspection, iron recipe and also subsequent nutrition improvement

Optimizing the electrodiagnostic accuracy in Guillain-Barré syndrome subtypes: Criteria sets and sparse linear discriminant analysis

Objective To optimize the electrodiagnosis of Guillain-Barré syndrome (GBS) subtypes at first study. Methods The reference electrodiagnosis was obtained in 53 demyelinating and 45 axonal GBS patients on the basis of two serial studies and results of anti-ganglioside antibodies assay. We retrospectively employed sparse linear discriminant analysis (LDA), two existing electrodiagnostic criteria sets (Hadden et al., 1998; Rajabally et al., 2015) and one we propose that additionally evaluates duration of motor responses, sural sparing pattern and defines reversible conduction failure (RCF) in motor and sensory nerves at second study. Results At first study the misclassification error rates, compared to reference diagnoses, were: 15.3% for sparse LDA, 30% for our criteria, 45% for Rajabally's and 48% for Hadden's. Sparse LDA identified seven most powerful electrophysiological variables differentiating demyelinating and axonal subtypes and assigned to each patient the diagnostic probability of belonging to either subtype. At second study 46.6% of axonal GBS patients showed RCF in two motor and 8.8% in two sensory nerves. Conclusions Based on a single study, sparse LDA showed the highest diagnostic accuracy. RCF is present in a considerable percentage of axonal patients. Significance Sparse LDA, a supervised statistical method of classification, should be introduced in the electrodiagnostic practice

Prevalence and Genetic Characterization of Methicillin-Resistant <i>Staphylococcus aureus</i> Isolated from Pigs in Japan

We investigated the prevalence of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in pig slaughterhouses from 2018 to 2022 in Japan and the isolates were examined for antimicrobial susceptibility and genetic characteristics by whole-genome analysis. Although the positive LA-MRSA rates on farms (29.6%) and samples (9.9%) in 2022 in Japan remained lower than those observed in European countries exhibiting extremely high rates of confirmed human LA-MRSA infections, these rates showed a gradually increasing trend over five years. The ST398/t034 strain was predominant, followed by ST5/t002, and differences were identified between ST398 and ST5 in terms of antimicrobial susceptibility and the resistance genes carried. Notably, LA-MRSA possessed resistance genes toward many antimicrobial classes, with 91.4% of the ST398 strains harboring zinc resistance genes. These findings indicate that the co-selection pressure associated with multidrug and zinc resistance may have contributed markedly to LA-MRSA persistence. SNP analysis revealed that ST398 and ST5 of swine origin were classified into a different cluster of MRSA from humans, showing the same ST in Japan and lacking the immune evasion genes (scn, sak, or chp). Although swine-origin LA-MRSA is currently unlikely to spread to humans and become a problem in current clinical practice, preventing its dissemination requires using antimicrobials prudently, limiting zinc utilization to the minimum required nutrient, and practicing fundamental hygiene measures

Axonal Dysfunction Precedes Motor Neuronal Death in Amyotrophic Lateral Sclerosis

<div><p>Wide-spread fasciculations are a characteristic feature in amyotrophic lateral sclerosis (ALS), suggesting motor axonal hyperexcitability. Previous excitability studies have shown increased nodal persistent sodium conductances and decreased potassium currents in motor axons of ALS patients, both of the changes inducing hyperexcitability. Altered axonal excitability potentially contributes to motor neuron death in ALS, but the relationship of the extent of motor neuronal death and abnormal excitability has not been fully elucidated. We performed multiple nerve excitability measurements in the median nerve at the wrist of 140 ALS patients and analyzed the relationship of compound muscle action potential (CMAP) amplitude (index of motor neuronal loss) and excitability indices, such as strength-duration time constant, threshold electrotonus, recovery cycle and current-threshold relationships. Compared to age-matched normal controls (n = 44), ALS patients (n = 140) had longer strength-duration time constant (SDTC: a measure of nodal persistent sodium current; p < 0.05), greater threshold changes in depolarizing threshold electrotonus (p < 0.05) and depolarizing current threshold relationship (i.e. less accommodation; (p < 0.05), greater superexcitability (a measure of fast potassium current; p < 0.05) and reduced late subexcitability (a measure of slow potassium current; p < 0.05), suggesting increased persistent sodium currents and decreased potassium currents. The reduced potassium currents were found even in the patient subgroups with normal CMAP (> 5mV). Regression analyses showed that SDTC (R = -0.22) and depolarizing threshold electrotonus (R = -0.22) increased with CMAP decline. These findings suggest that motor nerve hyperexcitability occurs in the early stage of the disease, and precedes motor neuronal loss in ALS. Modulation of altered ion channel function could be a treatment option for ALS.</p></div

Electrodiagnostic accuracy in polyneuropathies: supervised learning algorithms as a tool for practitioners

The interpretation of electrophysiological findings may lead to misdiagnosis in polyneuropathies. We investigated the electrodiagnostic accuracy of three supervised learning algorithms (SLAs): shrinkage discriminant analysis, multinomial logistic regression, and support vector machine (SVM), and three expert and three trainee neurophysiologists