Evaluation of optical interference in a combined measurement system used for assessment of tissue blood flow

A dual-wavelength pulse oximetry system combined with laser Doppler was developed for the assessment of perfusion. Red and infrared PPG and Doppler signals were recorded from a healthy volunteer in three studies at different measurement sites to investigate the interference between PPG and laser Doppler flowmetry (LDF). Good quality photoplethysmographic (PPG) and Doppler signals were detected simultaneously using this combined probe from the skin of the finger. The influence of the PPG light sources on LDF measurements was investigated; also the influence of the LDF light sources to the PPG measurements was studied. In the worst case, the apparent change in PPG amplitude when the LDF system was switched on was less than 8%, and the change in LDF flux amplitude when the PPG system was switched on was 14.7%

Evaluation of a combined reflectance photoplethysmography and laser Doppler flowmetry surface probe

Photoplethysmographic (PPG) signals were recorded from the fingers of 16 healthy volunteers with periods of timed and forced respiration. The aim of this pilot study was to compare estimations of arterial oxygen saturation (SpO2) recorded using a dedicated pulse oximetry system while subjects were breathing regularly with and without a mouthpiece containing a flow resistor. The experiments were designed to mimic the effects of mechanical ventilation in manaesthetized patients. The effect of estimated airway pressures of ±15 cmH2O caused observable modulation in the recorded red and PPG signals. SpO2 values were calculated from the pre-recorded PPG signals. Mean SpO2 values were 95.4% with the flow resistor compared with 97.3% with no artificial resistance, with statistical significance demonstrated using a Student’s t-test (P = 0.006)

Performance of a novel optical sensor for intraoperative assessment of intestinal viability - 'proof of principle' study

Introduction: Objective assessment of intestinal viability during surgery will allow surgeons to make informed decisions on the safety of intestinal anastomosis and to predict anastomotic related complications.1We investigated the performance of a novel dual sensor incorporating two established methods – photoplethysmography (PPG) and laser Doppler flowmetry (LDF) in a ‘proof of principle’ study. Method: Using the new probe, infrared and red PPG amplitude and LDF flux of the bowel surface were recorded by LDF and PPG simultaneously in 30 patients undergoing large bowel resection with or without anastomosis. Each patient had measurements at eight different time points: before and after colonic mobilisation, over the tumour, before and after ligation of major vascular pedicle, immediately before and after anastomosis (+/- 5 min) at distal and proximal limbs. Both laparoscopic and open resectional cases were included. The differences between the mean amplitude and flux between different measurements were analysed. Results: Twenty four laparoscopic and six open bowel resection cases had a total of 121 measurements recorded using the new probe. The mean IR AC amplitude in pre-ligation was 433 (± 189) mV and the mean IR AC in post ligation was 301 (± 152) mV. A statistically significant difference (P = 0.047) was observed between pre-ligation and post-ligation for the mean infrared PPG amplitude (student’s t-test). A considerable difference in mean amplitude between pre and post ligation for the red PPG was also observed (the mean amplitude for the red PPG fell by –25.6%). The amplitude of the infrared PPG increased after anastomosis by 38.2% at the proximal site and by 37.8% at the distal site. The amplitude of the red PPG also increased after anastomosis (by 6.3%) at the proximal site although the equivalent increase was not seen at the distal site. The LDF measurements did not follow the same pattern of the changes seen in PPG amplitude. Conclusion: The preliminary results show that simultaneous PPG/LDF measurements from a combined sensor is feasible and provide useful information on changes in pulse volume and blood flow. Although the differences in PPG amplitude achieved statistical significance, the LDF measurements produced confounding results, perhaps explained by motion artefacts. Further refinements in design of the probe are required to improve the probe-tissue optical interface and reduce motion artefact

Intraoperative monitoring of intestinal viability: Evaluation of a new combined sensor

A dual wavelength photoplethysmography (PPG) and laser Doppler flowmetry (LDF) sensor was developed to investigate the suitability of these techniques for monitoring bowel viability intraoperatively. Clinical measurements were obtained from thirty patients undergoing bowel surgery. Three measurements were performed at different stages of the operation. The amplitude of infrared PPG decreased from the baseline measurement to the pre-anastomosis measurement by 36% and LDF flux decreased by 21% for the same measurements. An increase of 33% in amplitude for infrared PPG was observed from the pre-anastomotic to post-anastomosis measurement; the equivalent increase was not seen for LDF flux. The results revealed that the sensor could potentially indicate changes in perfusion and blood flow at critical phases of surgery, thereby assisting in the early detection of inadequate blood supply in bowel tissue. The results also suggest that laser Doppler is more sensitive to movement artefact compared to PPG

Phenotypic and genotypic evaluation of fluoroquinolone resistance in clinical isolates of Staphylococcus aureus in Tehran

Background: Fluoroquinolones are broad-spectrum antibiotics widely used in the treatment of bacterial infections such as Staphylococcus aureus isolates. Resistance to these antibiotics is increasing. Material/Methods: The occurrence of mutations in the grlA and gyrA loci were evaluated in 69 fluoroquinolone-resistant S. aureus isolates from 2 teaching hospitals of Tehran University of Medical Sciences. Results: Out of the 165 S. aureus isolates, 87 (52.7) were resistant to methicillin and 69 (41.8) were resistant to fluoroquinolone. Fluoroquinolone-resistant S. atoms isolates had a mutation at codon 80 in the grlA gene and different mutational combinations in the gyrA gene. These mutational combinations included 45 isolates at codons 84 and 86,23 isolates at codons 84,86 and 106 and 1 isolate at codons 84, 86 and 90. Fluoroquinolone-resistant S. aureus isolates were clustered into 33 PFGE types. Conclusions: The findings of this study show that the fluoroquinolone-resistant S. aureus strains isolated in the teaching hospitals in Tehran had multiple mutations in the QRDRs region of both grlA and gyrA genes

Optimal technical management of stump closure following distal pancreatectomy: a retrospective review of 215 cases.

BACKGROUND: Pancreatic fistula (PF) is a major source of morbidity following distal pancreatectomy (DP). Our aim was to identify risk factors related to PF following DP and to determine the impact of technique of transection and stump closure. METHODS: We performed a retrospective review of 215 consecutive patients who underwent DP. Perioperative and postoperative data were collected and analyzed with attention to PF as defined by the International Study Group of Pancreatic Fistula. RESULTS: PF developed in 36 patients (16.7%); fistulas were classified as Grade A (44.4%), B (44.4%), or C (11.1%). The pancreas was transected with stapler (n = 139), cautery (n = 70), and scalpel (n = 3). PF developed in 19.8% of remnants which were stapled/oversewn and 27.7% that were stapled alone (p = 0.4). Of the 69 pancreatic remnants transected with cautery and oversewn, a fistula developed in 4.3% (p = 0.004 compared to stapled/oversewn; p = 0.006 compared to stapled/not sewn). The median length of postoperative hospital stay was significantly increased in patients who developed PF (10 vs. 6 days, p = 0.002) CONCLUSION: The method of transection and management of the pancreatic remnant plays a critical role in the formation of PF following DP. This series suggests that transection using electrocautery followed by oversewing of the pancreatic remnant has the lowest risk of PF

Групповая эргатическая совместимость авиационных операторов в процессе эксплуатации авионики

Рассмотрены проблемы групповой эргатической совместимости авиационных операторов (пилотов, авиадиспетчеров, технического персонала) и использования технических средств для оценки групповой эргатической совместимости операторов как средства повышения авиационной безопасности за счет более тщательного отбора кандидатов для совместной работы в составе лeтных и космических экипажей.Розглянуто питання проблеми групової ергатичної сумісності авіаційних операторів (пілотів, авіадиспетчерів, технічного персоналу) і використання технічних пристроїв для оцінки групової ергатичної сумісності операторів як засобу підвищення авіаційної безпеки за рахунок більш кращого відбору кандидатів для спільної роботи у складі льотних і космічних екіпажів.We issued the problems of group ergatic aircraft operators (pilots, air traffic controllers, technicians) and the use of technical devices to assess the compatibility of the group ergatic operators as means of improving aviation safety through a better selection of candidates to work together as part of flight and space crews. In this research article to better selection of candidates for collaboration in the space flight crews and the authors propose to use modern computers with appropriate software. This computer complex will answer a number of important issues related to ensuring: compatibility Soames, rational distribution of functions between components ergatic systems, proper interaction with the machine operators as well as each other in normal and special situations professional selection, preparation and training of aviation operators

IL10 Low-Frequency Variants in Behçet's Disease Patients

To explain the missing heritability after the genome-wide association studies era, sequencing studies allow the identification of low-frequency variants with a stronger effect on disease risk. Common variants in the interleukin 10 gene (IL10) have been consistently associated with Behçet's disease (BD) and the goal of this study is to investigate the role of low-frequency IL10 variants in BD susceptibility

Expression of Regulatory Platelet MicroRNAs in Patients with Sickle Cell Disease

Background: Increased platelet activation in sickle cell disease (SCD) contributes to a state of hypercoagulability and confers a risk of thromboembolic complications. The role for post-transcriptional regulation of the platelet transcriptome by microRNAs (miRNAs) in SCD has not been previously explored. This is the first study to determine whether platelets from SCD exhibit an altered miRNA expression profile. Methods and Findings: We analyzed the expression of miRNAs isolated from platelets from a primary cohort (SCD = 19, controls = 10) and a validation cohort (SCD = 7, controls = 7) by hybridizing to the Agilent miRNA microarrays. A dramatic difference in miRNA expression profiles between patients and controls was noted in both cohorts separately. A total of 40 differentially expressed platelet miRNAs were identified as common in both cohorts (p-value 0.05, fold change>2) with 24 miRNAs downregulated. Interestingly, 14 of the 24 downregulated miRNAs were members of three families - miR-329, miR-376 and miR-154 - which localized to the epigenetically regulated, maternally imprinted chromosome 14q32 region. We validated the downregulated miRNAs, miR-376a and miR-409-3p, and an upregulated miR-1225-3p using qRT-PCR. Over-expression of the miR-1225-3p in the Meg01 cells was followed by mRNA expression profiling to identify mRNA targets. This resulted in significant transcriptional repression of 1605 transcripts. A combinatorial approach using Meg01 mRNA expression profiles following miR-1225-3p overexpression, a computational prediction analysis of miRNA target sequences and a previously published set of differentially expressed platelet transcripts from SCD patients, identified three novel platelet mRNA targets: PBXIP1, PLAGL2 and PHF20L1. Conclusions: We have identified significant differences in functionally active platelet miRNAs in patients with SCD as compared to controls. These data provide an important inventory of differentially expressed miRNAs in SCD patients and an experimental framework for future studies of miRNAs as regulators of biological pathways in platelets. © 2013 Jain et al

Pattern recognition receptors as potential therapeutic targets in inflammatory rheumatic disease

The pattern recognition receptors of the innate immune system are part of the first line of defence against pathogens. However, they also have the ability to respond to danger signals that are frequently elevated during tissue damage and at sites of inflammation. Inadvertent activation of pattern recognition receptors has been proposed to contribute to the pathogenesis of many conditions including inflammatory rheumatic diseases. Prolonged inflammation most often results in pain and damage to tissues. In particular, the Toll-like receptors and nucleotide-binding oligomerisation domain-like receptors that form inflammasomes have been postulated as key contributors to the inflammation observed in rheumatoid arthritis, osteoarthritis, gout and systemic lupus erythematosus. As such, there is increasing interest in targeting these receptors for therapeutic treatment in the clinic. Here the role of pattern recognition receptors in the pathogenesis of these diseases is discussed, with an update on the development of interventions to modulate the activity of these potential therapeutic targets