Extraction of the pull force from inertial sensors during the pull test for Parkinson's disease: A reliability study

OBJECTIVE

To examine the inter- and intra-rater reliability of the pull test in patients with Parkinson's disease (PD) using the extracted pull force.

METHODS

In this inter- and intra-rater reliability study, two raters performed a pull test on 30 patients with PD. The pull force was quantified using inertial sensors attached to the rater's right hand and the patient's lower trunk. In this study, the pull force was calculated as an extracted three-dimensional vector quantity, the resultant acceleration, and was expressed in m/s2. Inter- and intra-rater reliabilities were analyzed using the interclass correlation coefficient (ICC) for the pull force and Cohen's weighted kappa (κw) for the pull test score. Furthermore, Bland-Altman analysis was used to investigate systematic errors.

RESULTS

The inter- and intra-rater reliability of the pull force was very poor (ICC = 0.033-0.214). Bland-Altman analysis revealed no systematic errors in the pull forces between the two test points. Conversely, κw for the pull test scores ranged from 0.763 to 0.920, indicating substantial to almost perfect agreement.

CONCLUSION

The pull test score was reliable despite variations in the quantified pull force for inter- and intra-rater reliability. Our findings suggest that the pull test is a robust tool for evaluating postural instability in patients with PD and that the pull force probably does not affect scoring performance.

Gastrointestinal cancer occurs as extramuscular manifestation in FSHD1 patients

Facioscapulohumeral dystrophy type1 (FSHD1) patients with a shortened D4Z4 repeat containing the DUX4 gene have a broad spectrum of clinical manifestations. In addition, high expression of DUX4 protein with an aberrant C terminus is frequently identified in B cell acute lymphoblastic leukemia. We investigated clinical manifestations in 31 FSHD1 patients and 30 non-affected individuals. Gastrointestinal cancers (gastric and colorectal cancers) increased after the age of 40 years and were more frequently observed in FSHD1 patients (n = 10) than in non-affected individuals (n = 2, p = 0.0217), though the incidence of cancers occurring in non-gastrointestinal tissues of FSHD1 patients was the same as that of non-affected individuals (p > 0.999). These comorbidities of FSHD1 patients were not associated with D4Z4 repeat number. Our results suggest that gastrointestinal cancers are among the extramuscular manifestations of adult FSHD1 patients, and do not depend on D4Z4 repeat number.

Advanced gallbladder cancer accompanied with cancer-associated dermatomyositis: A case report and literature review

RATIONALE

Muscle weakness due to cancer-associated dermatomyositis (CADM) can be misdiagnosed as cancer cachexia and disuse atrophy.

PATIENT CONCERNS

A 75-year-old female was admitted to our institute with muscle weakness, dysphagia, and suspected gallbladder cancer. Computed tomography and cytopathological examinations of the liver biopsy and fine-needle aspiration from swollen lymph nodes using endoscopic ultrasonography revealed cancer in the gallbladder body and metastasis to the lymph nodes around the abdominal aorta. We avoided the administration of anticancer drugs due to her poor general condition.

DIAGNOSIS

Subsequently, we diagnosed her with muscle weakness and dysphagia as a result of CADM using species from muscle and skin biopsy.

INTERVENTIONS AND OUTCOMES

Prednisolone therapy and anticancer agents partially improved the patient symptoms.

LESSONS

CADM is reported to be associated with a high incidence of dysphagia, which may aid in the diagnosis of this disease.

TDP-43 Accumulation Within Intramuscular Nerve Bundles of Patients With Amyotrophic Lateral Sclerosis

Importance

Degeneration of neuromuscular junctions and axons is considered an important aspect of the pathomechanism of amyotrophic lateral sclerosis (ALS). However, a mechanism including the role of transactive response DNA-binding protein 43 (TDP-43) in axons has not been pathologically clarified.

Objective

To identify and characterize the histopathology of peripheral axons in the skeletal muscle of patients with ALS.

Design, Setting, and Participants

This study comprised 2 parts: a postmortem case-control study and a retrospective population-based cohort study with a minimum of 1 year of follow-up. Patients in the cohort study were enrolled from January 1, 2004, to September 30, 2019. The postmortem study included patients with sporadic ALS (SALS) with TDP-43 pathology and control patients with non-ALS disease. The cohort study enrolled patients without a family history of ALS or other neuromuscular disease and those not diagnosed with a muscle disease at biopsy. Patients were excluded if their clinical records were not screened after biopsy, if they were diagnosed with a muscular disease, and if they were harboring known causative genes of ALS. Data were collected between September 2019 and June 2021 and analyzed in June 2021.

Exposures

Muscle biopsy or postmortem muscle tissue examination.

Main Outcomes and Measures

Clinical information and muscle pathological characteristics.

Results

A total of 10 patients with autopsy-confirmed SALS (mean [SD] age at death, 76.1 [8.5] years; 8 men [80%]) exhibited axonal phosphorylated TDP-43 (pTDP-43)-positive accumulations in intramuscular nerve bundles; the 12 control patients without ALS did not. Among the 114 patients in the cohort study (mean [SD] age, 62.3 [16.1] years; 76 men [67%]), 71 patients (62.3%) exhibited intramuscular nerve bundles; 43 (37.7%) did not. Among those who exhibited pTDP-43-positive intramuscular nerve bundles, 33 patients (22 men [66.7%]; mean [SD] age, 65.2 [15.6] years) were later diagnosed with ALS. The other 38 patients (26 men [68.4%]; mean [SD] age, 59.3 [18.0] years) showed no pTDP-43-positive bundles and did not develop ALS. Among those without evident nerve bundles (28 men [65.1%]; mean [SD] age, 61.3 [15.3] years), 3 were later diagnosed with ALS. Among patients with ALS in the biopsy cohort, 9 with pTDP-43-positive bundles showed only lower motor neuron symptoms at biopsy.

Conclusions and Relevance

Results of this dual case-control and retrospective cohort study suggest that axonal pTDP-43 accumulations may be characteristic for patients with ALS. As such findings precede clinical fulfillment of the Gold Coast criteria, TDP-43 in nerve bundles may be a novel diagnostic biomarker for ALS.

OP0112 THE EVER-LARGEST ASIAN GWAS FOR SYSTEMIC SCLEROSIS AND TRANS-POPULATION META-ANALYSIS IDENTIFIED SEVEN NOVEL LOCI AND A CANDIDATE CAUSAL SNP IN A CIS-REGULATORY ELEMENT OF THE FCGR REGION

Background

Genome-wide association studies (GWASs) have identified 29 disease-associated single nucleotide polymorphisms (SNPs) for systemic sclerosis (SSc) in non-human leukocyte antigen (HLA) regions (1-7). While these GWASs have clarified genetic architectures of SSc, study subjects were mainly Caucasians limiting application of the findings to Asians.

Objectives

The study was conducted to identify novel causal variants for SSc specific to Japanese subjects as well as those shared with European population. We also aimed to clarify mechanistic effects of the variants on pathogenesis of SSc.

Methods

A total of 114,108 subjects comprising 1,499 cases and 112,609 controls were enrolled in the two-staged study leading to the ever-largest Asian GWAS for SSc. After applying a strict quality control both for genotype and samples, imputation was conducted using the reference panel of the phase 3v5 1,000 genome project data combined with a high-depth whole-genome sequence data of 3,256 Japanese subjects. We conducted logistic regression analyses and also combined the Japanese GWAS results with those of Europeans (6) by an inverse-variance fixed-effect model. Polygenicity and enrichment of functional annotations were evaluated by linkage disequilibrium score regression (LDSC), Haploreg and IMPACT programs. We also constructed polygenic risk score (PRS) to predict SSc development.

Results

We identified three (FCRLA-FCGR, TNFAIP3, PLD4) and four (EOMES, ESR1, SLC12A5, TPI1P2) novel loci in Japanese GWAS and a trans-population meta-analysis, respectively. One of Japanese novel risk SNPs, rs6697139, located within FCGR gene clusters had a strong effect size (OR 2.05, P=4.9×10-11). We also found the complete LD variant, rs10917688, was positioned in cis-regulatory element and binding motif for an immunomodulatory transcription factor IRF8 in B cells, another genome-wide significant locus in our trans-ethnic meta-analysis and the previous European GWAS. Notably, the association of risk allele of rs10917688 was significant only in the presence of the risk allele of the IRF8. Intriguingly, rs10917688 was annotated as one enhancer-related histone marks, H3K4me1, in B cells, implying that FCGR gene(s) in B cells may play an important role in the pathogenesis of SSc. Furhtermore, significant heritability enrichment of active histone marks and a transcription factor C-Myc were found in B cells both in European and Japanese populations by LDSC and IMPACT, highlighting a possibility of a shared disease mechanism where abnormal B-cell activation may be one of the key drivers for the disease development. Finally, PRS using effects sizes of European GWAS moderately fit in the development of Japanese SSc (AUC 0.593), paving a path to personalized medicine for SSc.

Conclusion

Our study identified seven novel susceptibility loci in SSc. Downstream analyses highlighted a novel disease mechanism of SSc where an interactive role of FCGR gene(s) and IRF8 may accelerate the disease development and B cells may play a key role on the pathogenesis of SSc.

References

[1]F. C. Arnett et al. Ann Rheum Dis, 2010.

[2]T. R. Radstake et al. Nat Genet, 2010.

[3]Y. Allanore et al. PLoS Genet, 2011.

[4]O. Gorlova et al. PLoS Genet, 2011.

[5]C. Terao et al. Ann Rheum Dis, 2017.

[6]E. López-Isac et al. Nat Commun, 2019.

[7]W. Pu et al. J Invest Dermatol, 2021.

Disclosure of Interests

None declared

Clinical characteristics and tumor markers in ischemic stroke patients with active cancer

Cancer-associated ischemic stroke (CAS) refers to a hypercoagulation disorder related to malignant tumors, especially adenocarcinoma. Carbohydrate antigen (CA) 125 is a mucinous serum marker that might reflect hypercoagulation status, but the association between CA 125 and CAS is unclear across various types of cancer. The aim of this study was to investigate the associations among tumor markers, coagulation markers, and clinical factors in acute ischemic stroke (AIS) patients with active cancer. Consecutive AIS patients with active cancer (a diagnosis or ongoing active therapy for cancer within 6 months) were prospectively enrolled at four hospitals. D-dimer, C-reactive protein (CRP), carcinoembryonic antigen (CEA), CA19-9, and CA 125 levels were measured. Of 120 AIS patients with active cancer, 47 were diagnosed with CAS. CA 125 had the strongest correlations with D-dimer and CRP (ρ = 0.543, p < 0.001 and ρ = 0.452, p < 0.001, respectively). The areas under the receiver-operating characteristic curves for the diagnosis of CAS were 0.812 (95% CI 0.718-0.878) for CA 125, 0.714 (95% CI 0.602-0.801) for CEA, and 0.663 (95% CI 0.552-0.759) for CA 19-9. Multivariable analysis revealed that CA 125 levels in the highest quartile (OR 2.91, 95% CI 1.68-5.53), multiple lesions in multiple vascular territories observed on diffusion-weighted imaging, the absence of dyslipidemia, and the absence of atrial fibrillation were independently associated with CAS. Increased CA 125 levels, which indicate hypercoagulability, were useful for diagnosing CAS in AIS patients with active cancer.

Pembrolizumab-caused polyradiculoneuropathy as an immune-related adverse event

Immune‐related adverse events (irAEs) commonly involve the gastrointestinal tract, endocrine glands, skin, and liver, and rarely the nervous system. The pathomechanism of irAEs in the nervous system is unclear, and so characterizing these severe toxic effects is a priority, even if irAEs are uncommon in the nervous system. Our patient presented subacute muscle weakness and dysesthesia with colitis as irAEs caused by pembrolizumab, one of the anti‐programmed death‐1 (PD‐1) antibodies. Electromyography revealed abundant fibrillations and fasciculations of upper and lower extremities and severe reduction in motor unit potentials; however, antineutrophil cytoplasmic antibodies, rheumatoid factor, autoantibodies against Hu and Yo, and anti‐ganglioside antibodies, such as GQ1b, were undetectable in the serum. Although he was treated with high‐dose glucocorticoids, antibiotics, and a monoclonal anti‐tumor necrosis factor alpha (TNFα) antibody, he developed colonic perforation. The total colorectal resection was performed, and the resected colon showed mucosal defect and perforation. He died of lung aspergillosis. Postmortem examination revealed CD8‐positive lymphocyte infiltration around neurons of dorsal root ganglia. The sciatic nerve displayed the widening of myelin laminae and thinning of myelinated fibers but not a decrease in the density of myelinated nerve fibers. In the sural nerve, the density of myelinated fibers slightly decreased, and some fibers showed less densely myelinated laminae. Drug safety information, including previous randomized trials of anti‐PD‐1 and anti‐cytotoxic T‐lymphocyte–associated antigen‐4 (CTLA‐4) antibodies, showed that patients treated with anti‐PD‐1 antibodies appeared to have more frequent and severe peripheral neuropathies compared to those in patients who received anti‐CTLA‐4 antibodies (1.59% vs. 0.69%; Fisher exact test, P < 0.001; three severe events vs. zero severe events). The present results and drug safety information suggest that the pathomechanism of irAEs caused by anti‐PD‐1 antibodies is different from that by anti‐CTLA‐4 antibodies. The neurological irAEs might be clues to solving the pathomechanism of irAEs.

Analysis of genetic risk factors in Japanese patients with Parkinson's disease

Parkinson's disease (PD) is caused by a combination of genetic and environmental factors. Notably, genetic risk factors vary according to ethnicity and geographical regions, and few studies have analyzed the frequency of PD causative genes in Japanese patients. Therefore, we performed genetic analyses of Japanese patients with PD. We recruited 221 participants, including 26 patients with familial PD. Genetic risk factors were evaluated by target sequencing and gene dosage analysis. We detected the genetic risk factors in 58 cases (26.2%) and classified patients into three groups to clarify the differences in genetic risk factors by age at onset (AAO). The early-onset group (AAO < 50 years) included 18 cases (44.7%), who tended to have a larger number of genetic risk factors than the later-onset groups. Regarding the AAO for each causative gene, patients with PRKN variants were significantly younger at onset than those bearing LRRK2 variants. LRRK2 variants showed similar frequency in each AAO group. Of note, we identified two novel variants. Patients with early-onset PD have more genetic risk factors than patients with late-onset PD. In Japanese patients with PD, PRKN, and LRRK2 were the major PD-related genes. Particularly, LRRK2 was a common genetic factor in all age groups because of the presence of the Asian-specific variant such as LRRK2 p.G2385R. Accumulation of genetic and clinical data can contribute to the development of treatments for PD.

Anti-HMGCR Antibody-Positive Myopathy Shows Bcl-2-Positive Inflammation and Lymphocytic Accumulations

Anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) and antisignal recognition particle (SRP) antibodies are frequently associated with immune-mediated necrotizing myopathy (IMNM). However, the difference in clinical manifestations between anti-HMGCR and anti-SRP antibodies is unclear. HMGCR is an essential enzyme for cholesterol biosynthesis and is inhibited by statins that regulate apoptosis of Bcl-2-positive and beta chemokine receptor 4 (CCR4)-positive lymphoma cells. In this study, we aimed to clarify Bcl-2 and CCR4 expressions of lymphocytes in anti-HMGCR antibody-positive IMNM and explore the difference between anti-HMGCR antibody-positive myopathy and other inflammatory myopathies. We retrospectively examined Bcl-2- and CCR4-positive lymphocyte infiltrations in muscle and skin biopsy specimens from 19 anti-HMGCR antibody-positive patients and 75 other idiopathic inflammatory myopathies (IIMs) patients. A higher incidence of Bcl-2- and CCR4-positive lymphocytes was detected in the muscle and skin of anti-HMGCR antibody-positive IMNM patients (p < 0.001). In 5 patients with anti-HMGCR antibodies, Bcl-2-positive lymphocytes formed lymphocytic accumulations, which were not observed in other IIMs. Low-density lipoprotein cholesterol levels were not increased except for patients with Bcl-2-positive lymphocytic accumulations (p = 0.010). Bcl-2 and CCR4 lymphocyte infiltrations could be a pathological characteristic of anti-HMGCR antibody-positive IMNM.

Decreased stimulus-driven connectivity of the primary visual cortex during visual motion stimulation in amnestic mild cognitive impairment: An fMRI study

Motion perceptual deficits are common in Alzheimer's disease (AD). Although the posterior parietal cortex is thought to play a critical role in these deficits, it is currently unclear whether the primary visual cortex (V1) contributes to these deficits in AD. To elucidate this issue, we investigated the net activity or connectivity within V1 in 17 amnestic mild cognitive impairment (aMCI) patients, 17 AD patients and 17 normal controls (NC) using functional magnetic resonance imaging (fMRI). fMRI was recorded under two conditions: visual motion stimulation and resting-state. The net activity or connectivity within V1 extracted by independent component analysis (ICA) was significantly increased during visual motion stimuli compared with that of the resting-state condition in NC, but not in aMCI or AD patients. These findings suggest the alteration of the net activity or connectivity within V1, which may contribute to the previously reported motion perceptual deficits in aMCI and AD. Therefore, the decreased net V1 activity measured as the strength of the ICA component may provide a new disease biomarker for early detection of AD.

Warm Front Passage on the Previous Day Increased Ischemic Stroke Events

BACKGROUND AND PURPOSE

The influence of a weather front passage is rarely evaluated on stroke events. We hypothesized that a weather front passage on the stroke onset day or during the previous days may play an important role in the incidence of stroke.

METHODS

A multicenter retrospective study was conducted to evaluate the frequency of stroke events and their interaction with weather front passages. Consecutive acute stroke patients (n = 3935, 73.5 ± 12.4 years, 1610 females) who were admitted to 7 stroke hospitals in 3 cities from January 2012 to December 2013 were enrolled in this study. Multivariate Poisson regression models involving time lag variables were used to compare the daily rates of stroke events with the day of a weather front passage and the previous 6 days, adjusting for considerable influences of ambient temperature and atmospheric pressure.

RESULTS

There were a total of 33 cold fronts and 13 warm fronts that passed over the 3 cities during the study period. The frequency of ischemic stroke significantly increased when a warm front passed on the previous day (risk ratio 1.34, 95% confidence interval 1.07-1.69, P= .016).

CONCLUSIONS

This study indicated that a weather front passage on the previous days may be associated with the occurrence of stroke.

Auditory agnosia caused by bilateral putamen haemorrhage

A 55-year-old right-handed man with a history of hypertension suddenly fell and developed right hemiparesis. Neurological examination revealed that he was alert, but did not appropriately respond to verbal questions and commands. Detailed examination revealed that he could correctly respond to written commands. His speech was almost fluent, showing no paraphasia and normal articulation. His written sentences were legible. Pure tone audiometry showed that his auditory acuity was relatively preserved. His brainstem auditory evoked potential components from I to V were recorded bilaterally with normal latency. Cerebral CT demonstrated fresh bleeding in the left putamen and an old haemorrhage on the opposite side. He was treated by antihypertensive therapy and rehabilitation. Although there remained mild sensory deficit on his right extremities and he felt a slight noise during conversation, he had little difficulty with verbal communication when he was transferred to another hospital on day 38.

Various meteorological conditions exhibit both immediate and delayed influences on the risk of stroke events: The HEWS-stroke study

We hypothesized that meteorological conditions on the onset day and conditions on the former days may play important roles in the modulation of physical conditions. Associations of meteorological factors and their changes in former days with stroke onset are of interest. We conducted a multicenter retrospective study to evaluate the frequency of stroke events and their interaction with meteorological conditions and their daily changes. Acute stroke patients (n = 3935, 73.5±12.4 years, 1610 females) who were admitted to 7 stroke hospitals in three restricted areas were enrolled in this study. Poisson regression models involving time-lag variables was used to compare daily rates of stroke events with mean thermo-hydrological index (THI), atmospheric pressure, and their daily changes. We divided onset days into quintiles based on the THI, atmospheric pressure, and their daily changes for the last 7 days. The frequencies of ischemic stroke significantly increased when THI varied either cooler or warmer from a previous day (extremely cooler, risk ratio (RR) 1.19, 95% confidence interval (CI) 1.05 to 1.34; extremely warmer, RR 1.16, 95% CI 1.03 to 1.31; r2 = 0.001 for the best regression, p = 0.001). Intracerebral hemorrhage frequencies significantly decreased on high-THI days (extremely high, RR 0.72, 95% CI 0.54 to 0.95; r2 = 0.013 for the best regression, p<0.001) and increased in high atmospheric pressure days (high, RR 1.31, 95% CI 1.04 to 1.65; r2 = 0.009 for the best regression, p<0.001). Additionally, even after adjusting for the THI on the onset day and its changes for the other days, intracerebral hemorrhage increased when THI got extremely cooler in 4 days prior (RR 1.33, 95% CI 1.03 to 1.71, r2 = 0.006 for the best regression, p<0.001). Various meteorological conditions may exhibit influences on stroke onset. And, when temperature cooled, there may be a possibility to show delayed influence on the frequency of intracerebral hemorrhage 4 days later.

Modulation of motor cortex excitability by peripheral magnetic stimulation of different stimulus sites and frequencies

Peripheral stimulation is known to influence the state of cortical excitability. The purpose of this study is to investigate whether peripheral magnetic stimulation has similar effects on cortical excitability to transcranial magnetic stimulation (TMS). A magnetic stimulator with a flat figure-of-eight coil was used for both TMS, and peripheral magnetic stimulation applied to the bilateral forearms. TMS was performed on the left primary motor cortex to evaluate influence of the peripheral magnetic stimulation, and motor evoked potential (MEP) was measured from the right first dorsal interosseous. Peripheral magnetic stimulation was performed at a stimulus frequency of 1 Hz or 10 Hz, to the stimulus sites on the right and left supination of the forearm. The effects of peripheral magnetic stimulation were evaluated by comparing the mean MEP amplitude elicited by TMS before and after peripheral magnetic stimulation. We found that cortical excitability varied according to the stimulation site and frequency of the peripheral magnetic stimulation. The inhibition of cortical excitability was observed following 1 Hz peripheral magnetic stimulation over the right forearm (p<;0.001). In contrast, increased cortical excitability was observed using 1 Hz peripheral magnetic stimulation over the left forearm and 10 Hz stimulation over either the right or left forearms. We suggest that peripheral magnetic stimulation has a similar effect to TMS, and can induce both facilitation and inhibition of cortical excitability.

The impact of rTMS over the dorsolateral prefrontal cortex on cognitive processing

The purpose of the present study was to use event-related potentials (ERP) to clarify the effect of magnetic stimulation on cognitive processing. A figure eight-shaped flat repetitive transcranial magnetic stimulation (rTMS) coil was used to stimulate either the region over the left or the right dorsolateral prefrontal cortex, which is considered to be the origin of the P300 component. Stimulus frequencies were 1.00, 0.75 and 0.50 Hz rTMS. The strength of the magnetic stimulation was set at 80% of the motor threshold for each participant. The auditory oddball task was used to elicit P300s before and shortly after rTMS, and comprised a sequence of sounds containing standard (1 kHz pure tone, 80% of trials) and deviant (2 kHz pure tone, 20% of trials) stimuli. We found that a 1.00 Hz rTMS pulse train over the left dorsolateral prefrontal cortex increased P300 latencies by 8.50 ms at Fz, 12.85 ms at Cz, and 11.25 ms at Pz. In contrast, neither 0.75 and 0.50 Hz rTMS pulse trains over the left dorsolateral prefrontal cortex nor 1.00, 0.75 and 0.50 Hz rTMS pulse trains over the right dorsolateral prefrontal cortex altered P300 latencies. These results indicate that rTMS frequency affects cognitive processing. Thus, we suggest that the effects of rTMS vary according to the activity of excitatory and inhibitory neurons in the cerebral cortex.

Effects of Meteorological Conditions on the Risk of Ischemic Stroke Events in Patients Treated with Alteplase--HEWS-tPA

BACKGROUND

Predicting a day that presents a high risk for the occurrence of ischemic stroke events may enable health professionals to prepare for emergency stroke therapy more properly. We evaluated the association between meteorological conditions and the frequency of ischemic stroke events in Japanese patients.

METHODS

Ischemic stroke patients (n = 299) who were treated with alteplase at 9 stroke hospitals in 3 restricted areas were examined. The daily rates of ischemic stroke events were compared with the daily mean thermo-hydrological index (THI), the atmospheric pressure, and the daily changes of these variables for the 6 days preceding an ischemic stroke event using Poisson regression analysis.

RESULTS

We trisected onset days based on the THI (low-temperature, intermediate-temperature, and high-temperature), atmospheric pressure (low-pressure, intermediate-pressure, and high-pressure), changes in THI for preceding 6 days from the previous day (cooler, unchanged-temperature, and warmer), and changes in atmospheric pressure (decreased-pressure, unchanged-pressure, and increased-pressure). The frequency of ischemic stroke was significantly higher on low-temperature or high-pressure days (risk ratio, 1.398, P = .022; risk ratio, 1.374, P = .039), on warmer-temperature days, and when atmospheric pressure varied from the day before (P < .05). There were significantly lower risks for ischemic stroke events on cooler-temperature days, and higher risks were associated with a variation in atmospheric pressure 3 days before the onset from 4 days before (P < .05).

CONCLUSIONS

There were higher risks for ischemic stroke events associated with low ambient temperature, high atmospheric pressure, increased temperature, and varied atmospheric pressure. Also, atmospheric pressure variation 3 days before may be associated.

Hemodynamic stabilizing effects of L-carnitine in chronic hemodialysis patients

BACKGROUND

The effects of L-carnitine on the hemodynamic state of chronic hemodialysis patients have been debated. In order to clarify the effect of administered L-carnitine on cardiac function and hypotensive episodes during the hemodialysis procedure, a randomized double-blind placebo-controlled study was performed for 3 months.

METHODS AND RESULTS

TWENTY STABLE OUTPATIENTS UNDERGOING HEMODIALYSIS TREATMENT WERE DIVIDED INTO TWO GROUPS: controls (placebo) and treated patients (L-carnitine 900 mg p.o. daily). After 3 months, cardiac function was reevaluated by echocardiography, and hypotensive episodes during hemodialysis were assessed. Free and acyl carnitine levels increased significantly from 22.3 ± 7.1 to 140.3 ± 57.5 μmol/l and from 15.8 ± 2.8 to 94.8 ± 50.4 μmol/l, respectively, in the treated group. The ejection fraction significantly increased from 61.8 ± 16.0 to 64.4 ± 13.8% (p < 0.05) in the treated group. However, there was no difference in other echocardiographic parameters between the two groups. Hypotensive episodes significantly decreased from 4.0 ± 1.7 to 1.3 ± 0.9 times per month (p < 0.05), although patients' body weight did not change significantly.

CONCLUSIONS

Beneficial effects of L-carnitine on the hemodynamic state of chronic hemodialysis patients were observed. L-Carnitine supplementation might be considered especially for chronic hemodialysis patients with unstable hemodynamic conditions.

Time-dependent effects of low-frequency repetitive transcranial magnetic stimulation of the supramarginal gyrus

In this paper, we report our studies of the effects of stimulating the bilateral supramarginal gyrus (SMG) with low-frequency transcranial magnetic stimulation (rTMS) or short-term rTMS on brain excitability in humans. We analyzed the effects of various durations of stimulation on P300 latencies of the event-related potential (ERP). Magnetic pulses were delivered using a figure-eight flat coil. The intensity of rTMS was set to 80 % of the subject's motor threshold. In each round of rTMS, 100 magnetic pulses were applied over the scalp at frequencies of 1.00, 0.75, and 0.50 Hz. ERPs were measured prior to magnetic stimulation as a control. The effects of magnetic stimulation were then determined by measuring its effects on P300 latencies elicited by an odd-ball task. These latencies were measured before and 0, 5, 10, and 15 min after the magnetic stimulation. 1.00 Hz low-frequency rTMS of the left SMG decreased P300 latencies for approximately 10 min. In contrast, 0.50 Hz rTMS of the left SMG resulted in delayed P300 latencies for approximately 15 min. We furthermore found that 0.75 Hz rTMS of the left SMG and 1.00, 0.75 and 0.5 Hz rTMS of the right SMG did not affect P300 latencies. These results suggest that the duration of the effects of rTMS depend on the frequency of stimulation.

Dynamic chemical equilibrium in a polar desert pond: a sensitive index of meteorological cycles

The dramatic variation in the composition of a brine pond in Antarctica is a seasonal phenomenon. The phase relations of salts in solution are such that hydrologic conditions and temperature determine composition during the austral summer. Temperature is the primary determinant of composition during the winter.

Measurement of short-chain fatty acids in human faeces using high-performance liquid chromatography: specimen stability

BACKGROUND

Short-chain fatty acids such as lactic acid produced by the intestinal bacterial flora have various physiological actions involved in health, and it is important to determine the concentrations of faecal short-chain fatty acids and evaluate their relationship with large intestinal diseases. In this study, we evaluated the highly selective and sensitive simultaneous measurement of both volatile and non-volatile short-chain fatty acid hydrazides using high-performance liquid chromatography (HPLC).

MATERIALS AND METHODS

Faeces treated with ethanol were used as analytic samples. Short-chain fatty acids were measured as fatty acid hydrazides by HPLC.

RESULTS

For 12 types of short-chain fatty acid, the results regarding linearity, recovery tests and reproducibility were favourable. Faeces treated with ethanol could be stored at room temperature.

DISCUSSION

The stability of short-chain fatty acids in faeces at room temperature was statistically analysed. Faeces stored without treatment with ethanol showed increases/decreases in the concentrations of short-chain fatty acids, which may be due to assimilation by intestinal bacteria. However, specimen in 70% ethanol and stored in room temperature exhibited no substantial changes in concentrations of short-chain fatty acids up to seven days.

Observation of an energetic radiation burst from mountain-top thunderclouds

During thunderstorms on 20 September 2008, a simultaneous detection of gamma rays and electrons was made at a mountain observatory in Japan located 2770 m above sea level. Both emissions, lasting 90 sec, were associated with thunderclouds rather than lightning. The photon spectrum, extending to 10 MeV, can be interpreted as consisting of bremsstrahlung gamma rays arriving from a source which is 60-130 m in distance at 90% confidence level. The observed electrons are likely to be dominated by a primary population escaping from an acceleration region in the clouds.

Microfluidic large-scale integration on a chip for mass production of monodisperse droplets and particles

In this study, we report the mass production of monodisperse emulsion droplets and particles using microfluidic large-scale integration on a chip. The production module comprises a glass microfluidic chip with planar microfabricated 16-256 droplet-formation units (DFUs) and a palm-sized stainless steel holder having several layers for supplying liquids into the inlets of the mounted chip. By using a module having 128 cross-junctions (i.e., 256 DFUs) arranged circularly on a 4 cm x 4 cm chip, we could produce droplets of photopolymerizable acrylate monomer at a throughput of 320.0 mL h(-1). The product was monodisperse, having a mean diameter of 96.4 microm, with a coefficient of variation (CV) of 1.3%. Subsequent UV polymerization off the module yielded monodisperse acrylic microspheres at a throughput of approximately 0.3 kg h(-1). Another module having 128 co-flow geometries could produce biphasic Janus droplets of black and white segments at 128.0 mL h(-1). The product had a mean diameter of 142.3 microm, with a CV of 3.3%. This co-flow module could also be applied in the mass production of homogeneous monomer droplets.

Effect of continuous application of shear stress on liver tissue: continuous application of appropriate shear stress has advantage in protection of liver tissue

Rapid blood flow changes occur in the liver following a massive resection or in the grafted liver following transplantation, under which shear stress (SS) change induced by the flow change may determine the postoperative results. We observed changes in liver tissue structure and liver-specific function, and consequently assessed SS effect. The cultured liver tissue exposed to continuous application of moderate SS was shown to express and maintain a long-term liver-specific function. There was also evidence showing that destruction of the liver structure was inhibited. However, the cultured liver tissue not exposed to SS or exposed to high SS was shown to lose liver-specific function soon after expression. The liver structure was destroyed in the early stage of incubation. These results suggested that continuous application of appropriate SS has advantages over other types of stresses to protect liver tissue.

Effect of Mechanical Stress Imposition on Co-culture of Hepatic Parenchymal and Nonparenchymal Cells: Possibility of Stimulating Production of Regenerating Factor

The effect of mechanical stress generated within a three-dimensional bioreactor on the co-culture of hepatic parenchymal cells (PC) and hepatic nonparenchymal cells (NPC) was assessed to develop a bioartificial liver that can produce factors accelerating liver regeneration. A rotating radial flow bioreactor was used to provide mechanical stress to a co-culture of PC and NPC that were isolated from rats. They were co-cultured in the reactor under static or dynamic conditions. Albumin, interleukin-6 (IL-6), hepatocyte growth factor (HGF), and lactate dehydrogenase (LDH) were measured at intervals. Electron microscopy was also performed. LDH was not significantly different between the static and mechanical stress-loaded cultures, while albumin and interleukin-6 levels were higher in the latter at all sampling times. Only the co-cultures loaded with mechanical stress produced HGF in the early stage of culture (hours 3 and 6). Histologically, the cells retained their structure when cultured under dynamic conditions. These results suggested that an appropriate level of mechanical stress enabled co-cultures of PC and NPC to produce IL-6, HGF, and other factors that accelerate liver regeneration.

Dinucleotide repeat polymorphism in interferon-gamma gene is not associated with sporadic Alzheimer's disease

Various factors have been suggested to participate in Alzheimer's disease (AD) pathology, and some inflammatory cytokines may play an important role in the development of AD. Interferon-gamma (IFNG), an important pro-inflammatory cytokine, is encoded by a single gene mapped to chromosome 12, one of the candidate locus of AD. The first intron in the IFNG gene represents a CA repeat polymorphism that is possible to affect the IFNG secretion dose. We speculate that the polymorphism may have some roles on the inflammatory process and the pathologic change in AD, so we analyzed the IFNG gene polymorphism in 199 Japanese AD patients and 225 Japanese controls. There were no significant differences in allele frequency between the AD and control groups. We conclude that IFNG gene polymorphism is not associated with development of AD.

Dinucleotide repeat polymorphisms in the neprilysin gene are not associated with sporadic Alzheimer's disease

In the pathological process of Alzheimer's disease (AD), deposition of amyloid beta-peptide (A beta) in the brain parenchyma plays an important role. Neprilysin (NEP), a neutral endopeptidase, degrades A beta, and it is postulated that decreased NEP activity may contribute to the development of AD by promoting the accumulation of A beta. The human NEP gene possesses four dinucleotide repeat polymorphisms, and it is possible that these polymorphisms regulate the NEP expression levels and influence the pathological cascade of AD. Therefore, we investigated the association of these polymorphisms with AD. We performed genotyping of each polymorphism in 201 Japanese sporadic AD patients and 208 Japanese controls. There were no significant differences between the AD and control groups in allele frequencies of each polymorphism. We conclude that these polymorphisms in the NEP gene do not contribute to genetic risk factors for sporadic AD.

[The role of renal vasodepressor and natriuretic systems and ouabain-like factor on the early phase of hypertension in two-kidney, one-clip hypertensive rats]

Recent studies have shown that not only an enhanced renin-angiotensin system, but also relative volume retention might contribute to hypertension even in the early phase of a two-kidney, one-clip hypertensive model. To evaluate the role of renal depressor and natriuretic systems in the development of high blood pressure in the early phase of this model, we measured urinary excretion of kallikrein(uKAL), prostaglandin E2(uPGE2), and dopamine(uDA) in male Sprague-Dawley rats instrumented with a 0.2 mm diameter clip on the left renal artery(2K1C) and compared the results with those of sham-operated rats(sham). We also measured ouabain-like factor(OLF) in the plasma(pOLF) and urine(uOLF) in both groups. In 2K1C, systolic blood pressure(SBP) progressively increased and plasma renin activity was higher than the sham in the 3rd week. UDA and uPGE2 were not different between these groups, but uKAL attenuated in 2K1C in the 1st and 3rd week compared to the sham. There was a negative correlation between %delta SBP and %delta uKAL. On the other hand, uOLF increased in 2K1C in the 1st, 2nd and 3rd week compared to the sham. There was a positive correlation between SBP and uOLF. And pOLF was higher in 2K1C than in the sham. Furthermore there was a negative correlation between %delta uKAL and %delta uOLF. These results indicated that even in the early phase, suppression of the renal kallikrein-kinin system would contribute to high blood pressure in part, and OLF might play a compensatory role against the impaired natriuretic system in the kidney. However, OLF might contribute to blood pressure elevation through vasoconstriction in 2K1C.