Functional analysis of mutant and wild-type Drosophila origin recognition complex

The origin recognition complex (ORC) is the DNA replication initiator protein in eukaryotes. We have reconstituted a functional recombinant Drosophila ORC and compared activities of the wild-type and several mutant ORC variants. Drosophila ORC is an ATPase, and our studies show that the ORC1 subunit is essential for ATP hydrolysis and for ATP-dependent DNA binding. Moreover, DNA binding by ORC reduces its ATP hydrolysis activity. In vitro, ORC binds to chromatin in an ATP-dependent manner, and this process depends on the functional AAA(+) nucleotide-binding domain of ORC1. Mutations in the ATP-binding domain of ORC1 are unable to support cell-free DNA replication. However, mutations in the putative ATP-binding domain of either the ORC4 or ORC5 subunits do not affect either of these functions. We also provide evidence that the Drosophila ORC6 subunit is directly required for all of these activities and that a large pool of ORC6 is present in the cytoplasm, cytologically proximal to the cell membrane. Studies reported here provide the first functional dissection of a metazoan initiator and highlight the basic conserved and divergent features among Drosophila and budding yeast ORC complexes.     

Drug-induced sweat gland necrosis in a non-comatose patient: a case presentation

BACKGROUND: Coma-induced bullae and sweat gland necrosis is a rare clinicopathological entity often associated with drug-induced coma. SUBJECT: We report a case with clinical and histopathologic findings characteristic of blisters and sweat gland necrosis occurring in a non-comatose patient. CONCLUSIONS: Skin blisters with underlying sweat gland necrosis is an entity previously reported to occur in comatose patients, our findings open new questions about the role of the drugs in the pathogenesis of those conditions.     

A Method for Non-experts in Assessing Exposure to Risk Factors for Work-related Musculoskeletal Disorders—ERIN

A practical method for non-experts in assessing exposure to risk factors for work-related musculoskeletal disorders (WMSDs) is presented. Evaluación del Riesgo Individual (Individual Risk Assessment) (ERIN) is based on available ergonomic tools, epidemiological evidence and the joint IEA-WHO project for developing WMSDs risk management in developing countries. ERIN focuses primarily on the interaction of some physical workplace factors but also includes the workers’ assessment. A scoring system has been proposed to indicate the level of intervention required to reduce the risk of injury. A worksheet has also been designed for increasing the usability of the method. Preliminary tests show that it is easy and quick to use, but further work is needed to establish its reliability and validity. The use of ERIN can contribute to the prevention of WMSDs in Cuba and other developing countries.     

Spirituality and medicine

INTRODUCTION: Governing bodies for medical education recommend that spirituality and medicine be incorporated into training. AIM: To pilot a workshop on spirituality and medicine on a convenience sample of preclinical medical students and internal medicine residents and determine whether content was relevant to learners at different levels, whether preliminary evaluation was promising, and to generate hypotheses for future research. SETTING: Private medical school and university primary care internal medicine residency program, both in the Northeast. CURRICULUM DESCRIPTION: The authors designed and implemented a required 2-hour workshop for all second-year medical students and a separate required 1.5-hour workshop for all primary care internal medicine house staff. The workshops used multiple educational strategies including lecture, discussion, and role-play to address educational objectives. PROGRAM EVALUATION: Learners completed optional, anonymous pre and postworkshop surveys with six 5-point Likert-rated statements and space to cite the most useful part of the curriculum and their remaining questions. One hundred and thirty-seven learners participated and 100 completed both surveys. Medical students and residents had increased (all P< or =.002): agreement regarding the appropriateness of inquiring about spiritual and religious beliefs in the medical encounter, their perceived competence in taking a spiritual history, and their perceived knowledge of available pastoral care resources. Medical students, but not residents, had an increase in their perceived comfort in working with hospital chaplains. DISCUSSION: A brief pilot workshop on spirituality and medicine had a modest effect in improving attitudes and perceived competence of both medical students and residents.     

Complexity and spectral analysis of the heart rate variability dynamics for distant prediction of paroxysmal atrial fibrillation with artificial intelligence methods

OBJECTIVE: Paroxysmal atrial fibrillation (PAF) is a serious arrhythmia associated with morbidity and mortality. We explore the possibility of distant prediction of PAF by analyzing changes in heart rate variability (HRV) dynamics of non-PAF rhythms immediately before PAF event. We use that model for distant prognosis of PAF onset with artificial intelligence methods. METHODS AND MATERIALS: We analyzed 30-min non-PAF HRV records from 51 subjects immediately before PAF onset and at least 45min distant from any PAF event. We used spectral and complexity analysis with sample (SmEn) and approximate (ApEn) entropies and their multiscale versions on extracted HRV data. We used that features to train the artificial neural networks (ANNs) and support vector machine (SVM) classifiers to differentiate the subjects. The trained classifiers were further tested for distant PAF event prognosis on 16 subjects from independent database on non-PAF rhythm lasting from 60 to 320 min before PAF onset classifying the 30-min segments as distant or leading to PAF. RESULTS: We found statistically significant increase in 30-min non-PAF HRV recordings from 51 subjects in the VLF, LF, HF bands and total power (p<0.0001) before PAF event compared to PAF distant ones. The SmEn and ApEn analysis provided significant decrease in complexity (p<0.0001 and p<0.001) before PAF onset. For training ANN and SVM classifiers the data from 51 subjects were randomly split to training, validation and testing. ANN provided better results in terms of sensitivity (Se), specificity (Sp) and positive predictivity (Pp) compared to SVM which became biased towards positive case. The validation results of the ANN classifier we achieved: Se 76%, Sp 93%, Pp 94%. Testing ANN and SVM classifiers on 16 subjects with non-PAF HRV data preceding PAF events we obtained distant prediction of PAF onset with SVM classifier in 10 subjects (58+/-18 min in advance). ANN classifier provided distant prediction of PAF event in 13 subjects (62+/-21 min in advance). CONCLUSION: From the results of distant PAF prediction we conclude that ANN and SVM classifiers learned the changes in the HRV dynamics immediately before PAF event and successfully identified them during distant PAF prognosis on independent database. This confirms the reported in the literature results that corresponding changes in the HRV data occur about 60 min before PAF onset and proves the possibility of distant PAF prediction with ANN and SVM methods.