Effect of single-shot intrathecal morphine versus continuous epidural analgesia on length of stay after gastrectomy for cancer: a retrospective cohort study.

BACKGROUND: Single-dose intrathecal opiates (ITO) could shorten the length of hospital stay compared to thoracic epidural analgesia (TEA). This study aimed to compare TEA with TIO in terms of length of hospital stay, pain control, and parenteral opioid consumption in patients undergoing gastrectomy for cancer. METHODS: The patients who underwent gastrectomy for cancer in 2007-2018 at the CHU de Québec-Université Laval were included. The patients were grouped as TEA and intrathecal morphine (ITM). The primary outcome was the length of hospital of stay (LOS). The secondary outcomes were numeric rating scales (NRS) for pain and parenteral opioid consumption. RESULTS: A total of 79 patients were included. There were no differences in preoperative characteristics between the two groups (all P > 0.05). The median LOS was shorter in the ITM group than in the TEA group (median, 7.5 vs. 10 days, P = 0.049). The opioids consumption at 12, 24, and 48 h postoperatively was significantly lower in the TEA group at all time points. The NRS score for pain was lower in the TEA group than in the ITM group at all time points (all P < 0.05). CONCLUSIONS: Patients with ITM analgesia undergoing gastrectomy presented shorter LOS than those with TEA. ITM had an inferior pain control that did not have a clinical impact on recovery in the cohort studied. Given the limitations of this retrospective study, further trials are warranted.

The sequence features that define efficient and specific hAGO2-dependent miRNA silencing guides.

MicroRNAs (miRNAs) are ribonucleic acids (RNAs) of ∼21 nucleotides that interfere with the translation of messenger RNAs (mRNAs) and play significant roles in development and diseases. In bilaterian animals, the specificity of miRNA targeting is determined by sequence complementarity involving the seed. However, the role of the remaining nucleotides (non-seed) is only vaguely defined, impacting negatively on our ability to efficiently use miRNAs exogenously to control gene expression. Here, using reporter assays, we deciphered the role of the base pairs formed between the non-seed region and target mRNA. We used molecular modeling to reveal that this mechanism corresponds to the formation of base pairs mediated by ordered motions of the miRNA-induced silencing complex. Subsequently, we developed an algorithm based on this distinctive recognition to predict from sequence the levels of mRNA downregulation with high accuracy (r2 > 0.5, P-value < 10-12). Overall, our discovery improves the design of miRNA-guide sequences used to simultaneously downregulate the expression of multiple predetermined target genes.

Hemoglobin levels and transfusions in neurocritically ill patients: a systematic review of comparative studies.

INTRODUCTION: Accumulating evidence suggests that, in critically ill patients, a lower hemoglobin transfusion threshold is safe. However, the optimal hemoglobin level and associated transfusion threshold remain unknown in neurocritically ill patients. METHODS: We conducted a systematic review of comparative studies (randomized and nonrandomized) to evaluate the effect of hemoglobin levels on mortality, neurologic function, intensive care unit (ICU) and hospital length of stay, duration of mechanical ventilation, and multiple organ failure in adult and pediatric neurocritically ill patients. We searched MEDLINE, The Cochrane Central Register of Controlled Trials, Embase, Web of Knowledge, and Google Scholar. Studies focusing on any neurocritical care conditions were included. Data are presented by using odds ratios for dichotomous outcomes and mean differences for continuous outcomes. RESULTS: Among 4,310 retrieved records, six studies met inclusion criteria (n = 537). Four studies were conducted in traumatic brain injury (TBI), one in subarachnoid hemorrhage (SAH), and one in a mixed population of neurocritically ill patients. The minimal hemoglobin levels or transfusion thresholds ranged from 7 to 10 g/dl in the lower-Hb groups and from 9.3 to 11.5 g/dl in the higher-Hb groups. Three studies had a low risk of bias, and three had a high risk of bias. No effect was observed on mortality, duration of mechanical ventilation, or multiple organ failure. In studies reporting on length of stay (n = 4), one reported a significant shorter ICU stay (mean, -11.4 days (95% confidence interval, -16.1 to -6.7)), and one, a shorter hospital stay (mean, -5.7 days (-10.3 to -1.1)) in the lower-Hb groups, whereas the other two found no significant association. CONCLUSIONS: We found insufficient evidence to confirm or refute a difference in effect between lower- and higher-Hb groups in neurocritically ill patients. Considering the lack of evidence regarding long-term neurologic functional outcomes and the high risk of bias of half the studies, no recommendation can be made regarding which hemoglobin level to target and which associated transfusion strategy (restrictive or liberal) to favor in neurocritically ill patients.

Author Correction: A mutation in the methionine aminopeptidase gene provides phage resistance in Streptococcus thermophilus.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A mutation in the methionine aminopeptidase gene provides phage resistance in Streptococcus thermophilus.

Streptococcus thermophilus is a lactic acid bacterium widely used by the dairy industry for the manufacture of yogurt and specialty cheeses. It is also a Gram-positive bacterial model to study phage-host interactions. CRISPR-Cas systems are one of the most prevalent phage resistance mechanisms in S. thermophilus. Little information is available about other host factors involved in phage replication in this food-grade streptococcal species. We used the model strain S. thermophilus SMQ-301 and its virulent phage DT1, harboring the anti-CRISPR protein AcrIIA6, to show that a host gene coding for a methionine aminopeptidase (metAP) is necessary for phage DT1 to complete its lytic cycle. A single mutation in metAP provides S. thermophilus SMQ-301 with strong resistance against phage DT1. The mutation impedes a late step of the lytic cycle since phage adsorption, DNA replication, and protein expression were not affected. When the mutated strain was complemented with the wild-type version of the gene, the phage sensitivity phenotype was restored. When this mutation was introduced into other S. thermophilus strains it provided resistance against cos-type (Sfi21dt1virus genus) phages but replication of pac-type (Sfi11virus genus) phages was not affected. The mutation in the gene coding for the MetAP induces amino acid change in a catalytic domain conserved across many bacterial species. Introducing the same mutation in Streptococcus mutans also provided a phage resistance phenotype, suggesting the wide-ranging importance of the host methionine aminopeptidase in phage replication.

Hemoglobin thresholds and red blood cell transfusion in adult patients with moderate or severe traumatic brain injuries: A retrospective cohort study.

PURPOSE: We aimed to evaluate the association between transfusion practices and clinical outcomes in patients with traumatic brain injury. MATERIAL AND METHODS: We conducted a retrospective cohort study of adult patients with moderate or severe traumatic brain injury admitted to the intensive care unit (ICU) of a level I trauma center between 2009 and 2013. The associations between hemoglobin (Hb) level, red blood cell (RBC) transfusion and clinical outcomes were estimated using robust Poisson models and proportional hazard models with time-dependent variables, adjusted for confounders. RESULTS: We included 215 patients. Sixty-six patients (30.7%) were transfused during ICU stay. The median pre-transfusion Hb among transfused patients was 81g/L (IQR 67-100), while median nadir Hb among non-transfused patients was 110g/L (IQR 93-123). Poor outcomes were significantly more frequent in patients who were transfused (mortality risk ratio [RR]: 2.15 [95% CI 1.37-3.38] and hazard ratio: 3.06 [95% CI 1.57-5.97]; neurological complications RR: 3.40 [95% CI 1.35-8.56]; trauma complications RR: 1.65 [95% CI 1.31-2.08]; ICU length of stay geometric mean ratio: 1.42 [95% CI 1.06-1.92]). CONCLUSIONS: During ICU stay, transfused patients tended to have lower Hb levels and worse outcomes than patients who did not receive RBCs, after adjustment for confounders.

Red Blood Cell Transfusion in Patients With Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

Our objectives were to evaluate the frequency of red blood cell (RBC) transfusion in patients with traumatic brain injury (TBI) as well as potential determinants and outcomes associated with RBC transfusion in this population. We conducted a systematic review of cohort studies and randomized trials of patients with TBI. We searched Medline, Embase, the Cochrane Library, and BIOSIS databases from their inception up to April 2015. We selected studies of adult patients with acute TBI reporting data on RBC transfusions. Cumulative incidences of transfusion were pooled using random-effect models with a DerSimonian approach. To evaluate the association between RBC transfusion and potential determinants or clinical outcomes, we pooled risk ratios or mean differences with random-effect models and the Mantel-Haenszel method. We identified 24 eligible studies (17414 patients). After pooling data from 23 studies (7524 patients), approximately 36% (95% confidence interval [CI], 28-44; I(2) = 98%) of patients received RBC transfusion at some point during their hospital stay. Hemoglobin thresholds for transfusion were rarely available (reported in 9 studies) and varied from 6 to 10 g/dL. Glasgow Coma Scale scores at admission were lower in patients who were transfused than those who were not (3 cohort studies; 1371 patients; mean difference of 1.38 points [95% CI, 0.86-1.89]; I(2) = 12%). Mortality was not significantly different among transfused and nontransfused patients in univariate and multivariate meta-analyses. Hospital length of stay was longer among patients receiving RBC transfusion compared to those who did not (3 studies; n = 455; mean difference, 9.58 days [95% CI, 3.94-15.22]; I(2) = 74%). Results should be considered cautiously due to the high heterogeneity and high risk of confounding from the observational nature of included studies. Red blood cell transfusion is frequent in patients with TBI, and transfusion practices varied widely between studies. Current published data highlight the lack of clinical evidence guiding transfusion strategies in TBI.

Red blood cell transfusion in patients with traumatic brain injury: a systematic review protocol.

BACKGROUND: Anemia is a prevalent condition in critically ill patients and red blood cell transfusions are frequent. Although transfusions at low hemoglobin levels have been shown to be associated with equivalent or better outcomes than higher hemoglobin thresholds, clinical equipoise persists in patients with traumatic brain injury considering their susceptibility to secondary cerebral insults such as those from hypoxemia. METHODS: Our objectives are to estimate the frequency of red blood cell transfusion in patients with traumatic brain injury and to evaluate transfusion thresholds, determinants and outcomes associated with transfusion strategies.We will conduct a systematic review of cohort studies and randomized controlled trials of patients with traumatic brain injury. We will search MEDLINE, Embase, BIOSIS and the Cochrane Library for eligible studies. Two independent reviewers will screen all identified references. Studies including adult patients with traumatic brain injury reporting data on red blood cell transfusions will be eligible. We will collect data on baseline demographics, trauma characteristics, hemoglobin thresholds, blood transfusions and clinical outcomes (mortality, length of stay, complications, and so on). Two independent reviewers will extract data using a standardized form. We will pool cumulative incidences using DerSimonian and Lair random-effect models after a Freeman-Tukey transformation to stabilize variances. We will pool risk ratios or mean differences with random-effect models and Mantel-Haenszel or inverse variance methods in order to evaluate the association between red blood cell transfusion and potential determinants or outcomes. Sensitivity and subgroup analysis according to timing of red blood cell transfusion, traumatic brain injury severity, year of conduction of the study, risk of bias, notably, are planned. DISCUSSION: We expect to observe high heterogeneity in the proportion of transfused patients across studies and that the global proportion will be similar to the frequency observed in the general medical critically ill population. Our systematic review will allow us to better describe and understand current transfusion practices in patients with traumatic brain injury, a clinical population in which liberal transfusions are still advocated in the absence of evidence-based data. SYSTEMATIC REVIEW REGISTRATION PROSPERO: CRD42014007402.

Microvolume quantitation of nucleic acids.

Quantitation of DNA and RNA by absorbance and fluorescence spectroscopy has been a powerful tool in life sciences for decades. Classic methods of nucleic acid quantitation require the filling of devices, such as cuvettes and capillaries, with sample (traditional methodologies are described in APPENDIX 3D). Analysis of microvolume samples has become of paramount importance as more molecular biology techniques yield progressively smaller amounts of isolated sample and require accurate quantitation of nucleic acids with minimal consumption of sample. Advances in photonic technologies have resulted in a pioneering microvolume system that combines fiber optic technology with the inherent physical properties of the sample to dramatically reduce measurement volumes, removing the need for cuvettes and capillaries. Since the introduction of the first microvolume instrument, several new designs are now available, providing opportunities to measure nucleic acids using much smaller amounts of material. Altogether, these systems not only reduce measurement volume (as little as 0.5 to 2 µl), but also tend to be more efficient time-wise than traditional methods, making them useful even when sample is plentiful. The protocols in this unit are based on the most widely accepted microvolume systems and are intended as practical alternatives to traditional nucleic acid quantitation methodology.

NanoDrop microvolume quantitation of nucleic acids.

Biomolecular assays are continually being developed that use progressively smaller amounts of material, often precluding the use of conventional cuvette-based instruments for nucleic acid quantitation for those that can perform microvolume quantitation. The NanoDrop microvolume sample retention system (Thermo Scientific NanoDrop Products) functions by combining fiber optic technology and natural surface tension properties to capture and retain minute amounts of sample independent of traditional containment apparatus such as cuvettes or capillaries. Furthermore, the system employs shorter path lengths, which result in a broad range of nucleic acid concentration measurements, essentially eliminating the need to perform dilutions. Reducing the volume of sample required for spectroscopic analysis also facilitates the inclusion of additional quality control steps throughout many molecular workflows, increasing efficiency and ultimately leading to greater confidence in downstream results. The need for high-sensitivity fluorescent analysis of limited mass has also emerged with recent experimental advances. Using the same microvolume sample retention technology, fluorescent measurements may be performed with 2 µL of material, allowing fluorescent assays volume requirements to be significantly reduced. Such microreactions of 10 µL or less are now possible using a dedicated microvolume fluorospectrometer. Two microvolume nucleic acid quantitation protocols will be demonstrated that use integrated sample retention systems as practical alternatives to traditional cuvette-based protocols. First, a direct A260 absorbance method using a microvolume spectrophotometer is described. This is followed by a demonstration of a fluorescence-based method that enables reduced-volume fluorescence reactions with a microvolume fluorospectrometer. These novel techniques enable the assessment of nucleic acid concentrations ranging from 1 pg/ µL to 15,000 ng/ µL with minimal consumption of sample.

Microvolume spectrophotometric and fluorometric determination of protein concentration.

Methods for determining protein concentration that use progressively smaller amounts of material are continually being developed. A new way of minimizing the amount of sample used for spectroscopic analysis is providing more opportunities for greater quality control. Traditional spectrophotometric and fluorometric methods for determination of protein concentrations have long required placing samples into containment devices such as cuvettes or capillaries. A microsample retention system is changing that paradigm by using natural surface tension properties to capture and hold microvolume samples in place during measurement without traditional containment devices. The advantage of such a system is to dramatically reduce the amount of sample required (1 to 2 microl) while greatly increasing the dynamic range of protein concentrations that can be measured. Modifications to classic protein concentration determination protocols are presented to provide a microvolume alternative to traditional cuvette-based methods.

Microvolume protein concentration determination using the NanoDrop 2000c spectrophotometer.

Traditional spectrophotometry requires placing samples into cuvettes or capillaries. This is often impractical due to the limited sample volumes often used for protein analysis. The Thermo Scientific NanoDrop 2000c Spectrophotometer solves this issue with an innovative sample retention system that holds microvolume samples between two measurement surfaces using the surface tension properties of liquids, enabling the quantification of samples in volumes as low as 0.5-2 microL. The elimination of cuvettes or capillaries allows real time changes in path length, which reduces the measurement time while greatly increasing the dynamic range of protein concentrations that can be measured. The need for dilutions is also eliminated, and preparations for sample quantification are relatively easy as the measurement surfaces can be simply wiped with laboratory wipe. This video article presents modifications to traditional protein concentration determination methods for quantification of microvolume amounts of protein using A280 absorbance readings or the BCA colorimetric assay.

Quantitation of DNA and RNA with absorption and fluorescence spectroscopy.

Quantitation of nucleic acids is a fundamental tool in molecular biology that requires accuracy, reliability, and the use of increasingly smaller sample volumes. This unit describes the traditional absorbance measurement at 260 nm and three more sensitive fluorescence techniques, as well as three microvolume methods that use fiber optic technology in specialized cells or instrumentation. These procedures allow quantitation of DNA solutions ranging from 1 pg/liter to 50 mg/ml.

Quantitation of DNA and RNA with absorption and fluorescence spectroscopy.

Quantitation of nucleic acids is a fundamental tool in molecular biology that requires accuracy, reliability, and the use of increasingly smaller sample volumes. This unit describes the traditional absorbance measurement at 260 nm and three more sensitive fluorescence techniques, as well as three microvolume methods that use fiber optic technology in specialized cells or instrumentation. These procedures allow quantitation of DNA solutions ranging from 1 pg/microl to 50 mg/ml.

Quantitation of DNA and RNA with absorption and fluorescence spectroscopy.

Quantitation of nucleic acids is a fundamental tool in molecular biology that requires accuracy, reliability, and the use of increasingly smaller sample volumes. This unit describes the traditional absorbance measurement at 260 nm and three more sensitive fluorescence techniques, as well as three microvolume methods that use fiber optic technology in specialized cells or instrumentation. These procedures allow quantitation of DNA solutions ranging from 1 pg/l to 50 mg/ml.

Evolutionary implications of three novel members of the human sarcomeric myosin heavy chain gene family.

Sarcomeric myosin heavy chain (MyHC) is the major contractile protein of striated muscle. Six tandemly linked skeletal MyHC genes on chromosome 17 and two cardiac MyHC genes on chromosome 14 have been previously described in the human genome. We report the identification of three novel human sarcomeric MyHC genes on chromosomes 3, 7, and 20, which are notable for their atypical size and intron-exon structure. Two of the encoded proteins are structurally most like the slow-beta MyHC, whereas the third one is closest to the adult fast IIb isoform. Data from pairwise comparisons of aligned coding sequences imply the existence of ancestral genomes with four sarcomeric genes before the emergence of a dedicated smooth muscle MyHC gene. To further address the evolutionary relationships of the distinct sarcomeric and nonsarcomeric rod sequences, we have identified and further annotated human genomic DNA sequences corresponding to 14 class-II MyHCs. An extensive analysis provides a timeline for intron gain and loss, gene contraction and expansion, and gene conversion among genes encoding class-II myosins. One of the novel human genes is found to have introns at positions shared only with the molluscan catchin/MyHC gene, providing evidence for the structure of a pre-Cambrian ancestral gene.