The birth of piRNAs: how mammalian piRNAs are produced, originated, and evolved.

PIWI-interacting RNAs (piRNAs), small noncoding RNAs 24-35 nucleotides long, are essential for animal fertility. They play critical roles in a range of functions, including transposable element suppression, gene expression regulation, imprinting, and viral defense. In mammals, piRNAs are the most abundant small RNAs in adult testes and the only small RNAs that direct epigenetic modification of chromatin in the nucleus. The production of piRNAs is a complex process from transcription to post-transcription, requiring unique machinery often distinct from the biogenesis of other RNAs. In mice, piRNA biogenesis occurs in specialized subcellular locations, involves dynamic developmental regulation, and displays sexual dimorphism. Furthermore, the genomic loci and sequences of piRNAs evolve much more rapidly than most of the genomic regions. Understanding piRNA biogenesis should reveal novel RNA regulations recognizing and processing piRNA precursors and the forces driving the gain and loss of piRNAs during animal evolution. Such findings may provide the basis for the development of engineered piRNAs capable of modulating epigenetic regulation, thereby offering possible single-dose RNA therapy without changing the genomic DNA. In this review, we focus on the biogenesis of piRNAs in mammalian adult testes that are derived from long non-coding RNAs. Although piRNA biogenesis is believed to be evolutionarily conserved from fruit flies to humans, recent studies argue for the existence of diverse, mammalian-specific RNA-processing pathways that convert precursor RNAs into piRNAs, perhaps associated with the unique features of mammalian piRNAs or germ cell development. We end with the discussion of major questions in the field, including substrate recognition and the birth of new piRNAs.

Permeation of the three aromatic dipeptides through lipid bilayers: Experimental and computational study.

The time-resolved parallel artificial membrane permeability assay with fluorescence detection and comprehensive computer simulations are used to study the passive permeation of three aromatic dipeptides-N-acetyl-phenylalanineamide (NAFA), N-acetyltyrosineamide (NAYA), and N-acetyl-tryptophanamide (NATA) through a 1,2-dioleoyl-sn-glycero-3-phospocholine (DOPC) lipid bilayer. Measured permeation times and permeability coefficients show fastest translocation for NAFA, slowest for NAYA, and intermediate for NATA under physiological temperature and pH. Computationally, we perform umbrella sampling simulations to model the structure, dynamics, and interactions of the peptides as a function of z, the distance from lipid bilayer. The calculated profiles of the potential of mean force show two strong effects-preferential binding of each of the three peptides to the lipid interface and large free energy barriers in the membrane center. We use several approaches to calculate the position-dependent translational diffusion coefficients D(z), including one based on numerical solution the Smoluchowski equation. Surprisingly, computed D(z) values change very little with reaction coordinate and are also quite similar for the three peptides studied. In contrast, calculated values of sidechain rotational correlation times τrot(z) show extremely large changes with peptide membrane insertion-values become 100 times larger in the headgroup region and 10 times larger at interface and in membrane center, relative to solution. The peptides' conformational freedom becomes systematically more restricted as they enter the membrane, sampling α and ß and C7eq basins in solution, α and C7eq at the interface, and C7eq only in the center. Residual waters of solvation remain around the peptides even in the membrane center. Overall, our study provides an improved microscopic understanding of passive peptide permeation through membranes, especially on the sensitivity of rotational diffusion to position relative to the bilayer.

Anesthesia Risk Alert Program: A Proactive Safety Initiative.

BACKGROUND: Analyzing adverse events data collected over a three-year period on all anesthetic cases, North American Partners in Anesthesia (NAPA), a nationwide anesthesia practice, found a correlation between certain high-risk clinical factors and a number of critical events. Seeking to reduce the incidence of critical adverse events associated with these high-risk factors, the quality team of the NAPA Anesthesia Patient Safety Institute (NAPSI) developed the Anesthesia Risk Alert (ARA) program, which guides clinicians in proactively applying targeted risk mitigation interventions in five specific clinical scenarios. NAPSI is NAPA's Patient Safety Organization (PSO). METHODS: ARA promotes a proactive (Safety II) approach to patient safety. The protocol incorporates innovative collaboration techniques to improve clinical decision-making, along with recommendations by professional medical societies. ARA risk mitigation strategies also adapt decision tools from other industries, such as red team/blue team methodology. Following implementation training to approximately 6,000 NAPA clinicians, ongoing compliance is tracked for the program's two components: screening patients for the five high-risk clinical scenarios and performing the associated mitigation strategy when one or more risk factor is identified. RESULTS: Since launching the ARA program in 2019, clinician compliance consistently exceeds 95%. Simultaneously, available data indicate that the incidence of selected adverse events has decreased. CONCLUSION: ARA, developed as a process improvement initiative to reduce patient harm in several vulnerable perioperative patient populations, demonstrates how proactive safety strategies can improve clinical outcomes and create better perioperative cultures. At various sites, NAPA anesthesia clinicians reported that ARA's collaboration strategies were transformative behaviors that extended beyond the operating room. Other health care providers may customize the lessons learned from ARA with a Safety II approach.

A Retrospective Study: Multimodal Analgesia Quality Measure Implementation and Patient Outcome Assessment.

Current research has demonstrated that nonopioid multimodal analgesia decreases perioperative opioid consumption, postoperative nausea and vomiting (PONV), and pain scores. However, no research has been conducted to examine the patient outcomes of Merit-based Incentive Payment System (MIPS) 477. This study evaluates those outcomes following implementation of MIPS 477. The medical records of 400 adult patients who underwent elective and urgent laparoscopic gynecological procedures at a facility in the Mid-Atlantic region were reviewed. Data collection included patient characteristics, analgesics administered, pain scores at postanesthesia care unit (PACU) arrival and discharge, and antiemetic administration in PACU. This study's primary outcomes were postoperative pain scores, total intraoperative and postoperative opioid consumption, and PONV. Twenty-nine patients (7.8%) met the criteria as a control group, and 341 patients (92.2%) met the criteria as a treatment group. Pain scores were higher upon PACU arrival among the control group (P = .001). The total intraoperative morphine milligram equivalents (MMEs) administered was less among the treatment group (P = .04). The treatment group had reduced total intraoperative MMEs and pain scores at PACU arrival. However, there was no statistical significance in PACU discharge pain score, total PACU MMEs, and PONV in both groups.

Warm water infusion during sedated colonoscopy does not decrease amount of sedation medication used.

BACKGROUND: Water infusion versus air insufflation during colonoscope insertion has been suggested to reduce patient discomfort and decrease sedation medication requirements. Warm water is thought to further facilitate colonoscopy perhaps by decreasing colon spasm. OBJECTIVE: To compare the utility of warm (35°-38°C) versus cool (20°-23°C) water infused during colonoscopic insertion by measuring patient sedation medication use and discomfort scores between the warm and cool water groups. DESIGN: Randomized, controlled, double-blinded study. SETTING: Outpatient endoscopy unit at an academic medical center. PATIENTS: A total of 175 adults. INTERVENTION: Elective outpatient sedated screening colonoscopies. MAIN OUTCOME MEASUREMENTS: Sedation medication used, pain scores, cecal intubation rate, endoscopy times, satisfaction scores, and patient willingness to repeat procedures. RESULTS: There was no significant difference in sedation medication requirement during colonoscopy with the use of warm or cool water (fentanyl 83.6 ± 29.0 µg vs 87.6 ± 39.6 µg; P = .45; midazolam 3.3 ± 1.2 mg vs 3.3 ± 1.3 mg; P = .91). There was no significant difference in patient pain scores or satisfaction scores. Cecal intubation rates (100%) were similar. There was no significant difference in cecal intubation times (6 minutes 40 seconds ± 4 minutes 9 seconds vs 7 minutes 49 seconds ± 4 minutes 0 seconds; P = .06) between the warm and cool water groups. All patients were willing to repeat the colonoscopy by using the same method in both groups. LIMITATIONS: Limited generalizability to patients undergoing screening sedated colonoscopies with good to excellent bowel preparation. CONCLUSION: Water does not need to be warmed before infusion in patients undergoing sedated colonoscopies.

Guideline adherence and outcomes in esophageal variceal hemorrhage: comparison of tertiary care and non-tertiary care settings.

BACKGROUND: Implementation of consensus guidelines for esophageal variceal hemorrhage yields improved outcomes. We evaluated guideline adherence and outcomes after variceal hemorrhage at a university hospital (UH) and a staff-model health maintenance organization (HMO). STUDY: Factors associated with short-term bleeding, infection, and death were retrospectively identified in UH (n=160) and HMO (n=123) patients with esophageal variceal hemorrhage from January 2000 to December 2006. A second analysis of factors associated with long-term rebleeding was conducted in patients who survived ≥14 days without rebleeding. RESULTS: UH patients were younger, with more severe liver disease and overall illness (P<0.01). UH patients more often received vasoactive agents and prophylactic antibiotics (P<0.01), however the rate of endoscopic therapy did not differ. Infections at 14-days were similar (18.2% vs. 13.0%, P=0.25), but UH patients had greater in-hospital rebleeding (16.4% vs. 5.7%, P<0.01) and mortality (15.2% vs. 4.1%, P<0.01). Poor liver function and overall illness predicted infection, rebleeding, and death (adjusted odds ratio 2.75 to 13.39). Long-term rebleeding occurred in 36.1% of UH patients and 25.9% of HMO patients. Secondary prophylaxis reduced late rebleeding (hazard ratio 0.37 to 0.41). Poor liver function did not predict late rebleeding. Adherence to secondary prophylaxis was greater at the HMO (P<0.05), but late rebleeding did not differ (36% vs. 26%, P=0.13). CONCLUSIONS: Irrespective of practice setting, poor liver function and critical illness predicted short-term bleeding, infection, and death after esophageal variceal hemorrhage, and secondary prophylaxis prevented long-term rebleeding. Differing guideline adherence did not influence outcomes between tertiary care and non-tertiary care centers.

Prevalence of colon polyps detected by colonoscopy screening of asymptomatic Hispanic patients.

BACKGROUND: Compared with whites, Hispanics have lower incidence of and mortality from colorectal cancer. The purpose of this study was to determine whether asymptomatic Hispanics undergoing colonoscopy screening also have lower age-adjusted incidence of polyps ≥ 10 mm. Such data could be used to formulate future screening guidelines. AIMS: The objectives of this study were to measure and analyze the prevalence and location of polyps sized ≥ 10 mm in asymptomatic white and Hispanic patients who received colonoscopy screening. METHODS: Colonoscopy data were prospectively collected from the Clinical Outcomes Research Initiative database, which includes data from a consortium of 66 adult gastrointestinal practice sites in the United States. Asymptomatic white (n = 146,798) and Hispanic (n = 7,654) patients who received colonoscopy screening from 2004 to 2007 were identified. The prevalence of any polyps ≥ 10 mm and of proximal polyps ≥ 10 mm was adjusted for age, sex, practice site type, and family history of colorectal cancer in a multivariate analysis. RESULTS: There was no significant difference between prevalence of polyps ≥ 10 mm in Hispanic and white patients (5.8% vs. 6.2%; P = 0.11; adjusted OR 0.94; 95% CI 0.85-1.03). There was also no significant difference between prevalence of proximal polyps ≥ 10 mm in Hispanics and whites (adjusted OR 1.05; 95% CI 0.87-1.27). CONCLUSION: Despite lower incidence of colorectal cancer, the risk of polyps ≥ 10 mm for Hispanic patients undergoing colonoscopy screening is similar to that for whites. These data emphasize the importance of encouraging timely colorectal cancer screening in Hispanics. Our findings support the application of similar recommendations for colorectal cancer screening of Hispanics and whites.

Unassisted N-acetyl-phenylalanine-amide transport across membrane with varying lipid size and composition: kinetic measurements and atomistic molecular dynamics simulation.

Biological membranes are essential to preserve structural integrity and regulate functional properties through the permeability of nutrients, pharmaceutical drugs, and neurotransmitters of a living cell. The movement of acetylated and amidated phenylalanine (NAFA) across 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membrane bilayers is investigated to probe physical transport. The rate of transport is measured experimentally applying parallel artificial membrane permeation assay (PAMPA). At the physiological temperature, 310 K, the measured time constants in the neutral pH were ∼6 h in DOPC and ∼3 h in POPC, while in a more acidic condition, at a pH 4.8, the time constants were ∼8 h in both lipids. Computationally, we have expanded our transport study of three aromatic dipeptides across a bilayer composed of DOPC18. In this study, we have examined the effects of lipid composition and bilayer size on the passive transport of NAFA by simulating the dipeptide in three different bilayers, with 50 DOPC lipids, 50 POPC lipids, and 40 POPC molecules. Specifically, atomistic molecular dynamics simulations with umbrella sampling were used to calculate the potential of mean force for the passive permeation of NAFA across the bilayers. Diffusion constants were then calculated by numerically solving the Smoluchowski equation. Permeability coefficients and mean first passage times were then calculated. Structural properties - Ramachandran plots, sidechain torsions, peptide insertion angles, radial distribution functions, and proximal peptide water molecules - were also examined to determine the effect of system size and lipid type. In terms of systems size, we observed a small decrease in the highest barrier of the potential of mean force and fewer sampled sidechain dihedral angle conformations with 40 versus 50 POPC lipids due to weaker membrane deformations within a smaller lipid bilayer. In terms of lipid type, DOPC contains two monounsaturated acyl chains compared to only one such acyl chain in POPC; therefore, DOPC bilayers are less ordered and more easily deformed, as seen by a much broader potential of mean force profile. The NAFA in DOPC lipid also transitioned to an internally hydrogen-bonded backbone conformation at lower membrane depths than in POPC. Similarly, as for other aromatic dipeptides, NAFA tends to insert into the membrane sidechain-first, remains mostly desolvated in the membrane center, and exhibits slow reorientations within the bilayer in both DOPC and POPC. With a joint experimental and computational study we have gained a new insight into the rate of transport and the underlying microscopic mechanism in different lipid bilayer conditions of the simplest hydrophobic aromatic dipeptide.Communicated by Ramaswamy H. Sarma.

Activity Segmentation Using Wearable Sensors for DVT/PE Risk Detection.

Using a wearable electromyography (EMG) and an accelerometer sensor, classification of subject activity state (i.e., walking, sitting, standing, or ankle circles) enables detection of prolonged "negative" activity states in which the calf muscles do not facilitate blood flow return via the deep veins of the leg. By employing machine learning classification on a multi-sensor wearable device, we are able to classify human subject state between "positive" and "negative" activities, and among each activity state, with greater than 95% accuracy. Some negative activity states cannot be accurately discriminated due to their similar presentation from an accelerometer (i.e., standing vs. sitting); however, it is desirable to separate these states to better inform the risk of developing a Deep Vein Thrombosis (DVT). Augmentation with a wearable EMG sensor improves separability of these activities by 30%.

Outbreak of varicella at a day-care center despite vaccination.

BACKGROUND: In seven studies of the effectiveness of the varicella vaccine conducted since it was licensed, the effectiveness was 71 to 100 percent against disease of any severity and 95 to 100 percent against moderate and severe disease. We investigated an outbreak of varicella in a population of children with a high proportion of vaccinees who were attending a day-care center in a small community in New Hampshire. METHODS: Using standardized questionnaires, we collected information about the children's medical and vaccination history from parents and health care providers. The analysis of the effectiveness of the vaccine and of risk factors for vaccine failure was restricted to children who were enrolled in the day-care center continuously during the outbreak and attended for one week or more and who were cared for in the building that represented the epicenter of the outbreak, since transmission was not documented in a second building. RESULTS: Varicella developed in 25 of 88 children (28.4 percent) between December 1, 2000, and January 11, 2001. The index case occurred in a healthy child who had been vaccinated three years previously and who infected more than 50 percent of his classmates who had no history of varicella. The effectiveness of the vaccine was 44.0 percent (95 percent confidence interval, 6.9 to 66.3 percent) against disease of any severity and 86.0 percent (95 percent confidence interval, 38.7 to 96.8 percent) against moderate or severe disease. Children who had been vaccinated three years or more before the outbreak were at greater risk for vaccine failure than those who had been vaccinated more recently (relative risk, 2.6 [95 percent confidence interval, 1.3 to 5.3]). CONCLUSIONS: In this outbreak, vaccination provided poor protection against varicella, although there was good protection against moderate or severe disease. A longer interval since vaccination was associated with an increased risk of vaccine failure. Breakthrough infections in vaccinated, healthy persons can be as infectious as varicella in unvaccinated persons.

Transjugular Intrahepatic Portosystemic Shunt Prior to Endoscopic Mucosal Resection for Barrett's Esophagus in the Setting of Varices.

Patients with Barrett's esophagus (BE) and cirrhosis who develop high-grade dysplasia (HGD) or adenocarcinoma in the setting of esophageal varices present a unique therapeutic dilemma. There is limited literature regarding the optimal management of varices prior to invasive procedures or surgery involving the distal esophagus. We present a case of variceal decompression with a transjugular intrahepatic portosystemic shunt (TIPS) allowing for successful endoscopic mucosal resection (EMR) of BE with HGD overlying esophageal varices.

Population data for 15 STR loci (Identifiler kit) in a Filipino population.

Allele frequencies for fifteen STR loci, D3S1358, TH01, D21S11, D18S51, D2S1338, D5S818, D13S317, D7S820, D16S539, CSF1PO, D19S433, vWA, D8S1179, TPOX and FGA, were investigated in a Filipino ethnic group resident in the United States and in the Philippines. Statistical evaluation of the data collected indicated the population to be in Hardy-Weinberg equilibrium and therefore acceptable for calculations in forensic and family relatedness casework.

Measles hospitalizations, United States, 1985-2002.

Cases of measles that require hospitalization are a good marker of the burden of clinically severe measles in the United States. Measles hospitalizations routinely are monitored by the National Notifiable Disease Surveillance System (NNDSS). Our objectives were to describe measles hospitalizations reported to the NNDSS in 1985-2002, to use hospital discharge data from independent data sets (the National Hospital Discharge Survey [NHDS] [data available for 1985-1999] and the Health Care Investment Analysts [HCIA] hospital discharge database [data available for 1985-1996]) to provide additional estimates of total measles hospitalizations, and to compare trends in measles-associated hospitalizations. In 1985-2002, a total of 13621 patients with measles reported to the NNDSS were hospitalized (annual average, 757; range, 19-5856 patients). In 1985-1996, a total of 13472 measles hospitalizations were reported from NNDSS, compared with 28047 estimated from the NHDS and 19352 extrapolated from HCIA data. In the NNDSS, the annual total number declined after 1992 to