Discrimination of vascular aging using the arterial pulse spectrum and machine-learning analysis.

Aging contributes to the progression of vascular dysfunction and is a major nonreversible risk factor for cardiovascular disease. The aim of this study was to determine the effectiveness of using arterial pulse-wave measurements, frequency-domain pulse analysis, and machine-learning analysis in distinguishing vascular aging. Radial pulse signals were measured noninvasively for 3 min in 280 subjects aged 40-80 years. The cardio-ankle vascular index (CAVI) was used to evaluate the arterial stiffness of the subjects. Forty frequency-domain pulse indices were used as features, comprising amplitude proportion (Cn), coefficient of variation of Cn, phase angle (Pn), and standard deviation of Pn (n = 1-10). Multilayer perceptron and random forest with supervised learning were used to classify the data. The detected differences were more prominent in the subjects aged 40-50 years. Several indices differed significantly between the non-vascular-aging group (aged 40-50 years; CAVI <9) and the vascular-aging group (aged 70-80 years). Fivefold cross-validation revealed an excellent ability to discriminate the two groups (the accuracy was >80%, and the AUC was >0.8). For subjects aged 50-60 and 60-70 years, the detection accuracies of the two trained algorithms were around 80%, with AUCs of >0.73 for both, which indicated acceptable discrimination. The present method of frequency-domain analysis may improve the index reliability for further machine-learning analyses of the pulse waveform. The present noninvasive and objective methodology may be meaningful for developing a wearable-device system to reduce the threat of vascular dysfunction induced by vascular aging.

Classification of patients with Alzheimer's disease using the arterial pulse spectrum and a multilayer-perceptron analysis.

Cerebrovascular atherosclerosis has been identified as a prominent pathological feature of Alzheimer's disease (AD); the link between vessel pathology and AD risk may also extend to extracranial arteries. This study aimed to determine the effectiveness of using arterial pulse-wave measurements and multilayer perceptron (MLP) analysis in distinguishing between AD and control subjects. Radial blood pressure waveform (BPW) and finger photoplethysmography signals were measured noninvasively for 3 min in 87 AD patients and 74 control subjects. The 5-layer MLP algorithm employed evaluated the following 40 harmonic pulse indices: amplitude proportion and its coefficient of variation, and phase angle and its standard deviation. The BPW indices differed significantly between the AD patients (6247 pulses) and control subjects (6626 pulses). Significant intergroup differences were found between mild, moderate, and severe AD (defined by Mini-Mental-State-Examination scores). The hold-out test results indicated an accuracy of 82.86%, a specificity of 92.31%, and a 0.83 AUC of ROC curve when using the MLP-based classification between AD and Control. The identified differences can be partly attributed to AD-induced changes in vascular elastic properties. The present findings may be meaningful in facilitating the development of a noninvasive, rapid, inexpensive, and objective method for detecting and monitoring the AD status.

Epidural abscess caused by Veillonella parvula: Case report and review of the literature.

Veillonella parvula, an anaerobic, Gram-negative coccus is part of the normal flora of the oral, gastrointestinal, respiratory, and genitourinary tracts in humans and animals. We herein present a case of epidural abscess caused by V. parvula in a 68-year-old man with sinus squamous cell carcinoma who presented with a 3-week history of low back pain. Blood and pus cultures were positive for Veillonella spp. After sequencing of the 16S ribosomal DNA, the pathogen was identified as V. parvula. Surgical debridement was performed following which the patient received intravenous administration of amoxicillin/clavulanate. To our knowledge, there are only seven reported cases of spinal infection caused by Veillonella spp. and these are reviewed here.

The association between zolpidem and infection in patients with sleep disturbance.

OBJECTIVE: Recent case reports suggest that zolpidem usage may be associated with infection events. The aim of this study was to determine the risk of infection events in patients with sleep disturbance taking zolpidem in a full 3-year follow-up study. METHODS: A total of 17474 subjects with a diagnosis of sleep disturbance in 2002 and 2003 were identified, of whom 5882 had used zolpidem after recruitment. A Cox proportional hazard model was used to estimate the 3-year infection event-free rates for the patients using zolpidem and those not using zolpidem after adjusting for confounding factors. To maximize case ascertainment, only patients hospitalized for infection events were included. RESULTS: A total of 646 patients had had infection events, 331 (5.63%) of whom had been taking zolpidem and 315 (2.71%) had not. Zolpidem usage increased the risk of infection events. After adjustments for gender, age, co-morbidities, and other medications, patients using zolpidem with cDDD 1-28, 29-84, and >84 had hazard ratios of 1.67 (95% CI, 1.32-2.11), 1.91 (95% CI, 1.47-2.49) and 1.62 (95% CI, 1.32-1.98) respectively, compared with patients who did not use zolpidem. CONCLUSIONS: Zolpidem increased the risk of infection events in sleep disturbance patients. This increased risk of infection should be explained to sleep disturbance patients, and prescriptions of zolpidem to chronic insomnia patients should be restricted.

Septic arthritis caused by Mycobacterium fortuitum and Mycobacterium abscessus in a prosthetic knee joint: case report and review of literature.

Nontuberculous mycobacterium (NTM) is an infrequent cause of prosthetic knee joint infections. Simultaneous infection with different NTM species in a prosthetic knee joint has not been previously reported. A case of prosthetic knee joint infection caused by Mycobacterium abscessus and M. fortuitum is described in this report. The patient was successfully treated with adequate antibiotics and surgery. The clinical features of sixteen previously reported cases of prosthetic knee joint infection caused by NTM are reviewed.