Genotoxic Agents Produce Stressor-Specific Spectra of Spectinomycin Resistance Mutations Based on Mechanism of Action and Selection in Bacillus subtilis.

Mutagenesis is integral for bacterial evolution and the development of antibiotic resistance. Environmental toxins and stressors are known to elevate the rate of mutagenesis through direct DNA toxicity, known as stress-associated mutagenesis, or via a more general stress-induced process that relies on intrinsic bacterial pathways. Here, we characterize the spectra of mutations induced by an array of different stressors using high-throughput sequencing to profile thousands of spectinomycin-resistant colonies of Bacillus subtilis. We found 69 unique mutations in the rpsE and rpsB genes, and that each stressor leads to a unique and specific spectrum of antibiotic-resistance mutations. While some mutations clearly reflected the DNA damage mechanism of the stress, others were likely the result of a more general stress-induced mechanism. To determine the relative fitness of these mutants under a range of antibiotic selection pressures, we used multistrain competitive fitness experiments and found an additional landscape of fitness and resistance. The data presented here support the idea that the environment in which the selection is applied (mutagenic stressors that are present), as well as changes in local drug concentration, can significantly alter the path to spectinomycin resistance in B. subtilis.

Lack of Lymphocyte Recovery After Esophagectomy Predicts Overall and Recurrence-Free Survival.

BACKGROUND: Lymphocytes have become the target of cancer interventions through engineering or immune checkpoint antibodies. We previously found decreased lymphocyte counts to be a predictor of mortality and complications in trauma and cardiac surgery patients. We hypothesized lack of lymphocyte count recovery postoperatively would predict outcomes in esophagectomy patients. METHODS: A retrospective review of all patients undergoing esophagectomy for adenocarcinoma performed over 13 y at our center by a single surgeon after institutional review board approval was performed. Patients were grouped by postoperative lymphocytes counts: never low, low with recovery, and low without recovery. Resolution of lymphopenia was assessed by day 4. Primary end points were overall and recurrence-free survival. RESULTS: In total, 198 patients were included with a minimum 6-mo follow-up. Collectively the 5-y recurrence and overall survival rates were 36% and 50%, respectively. Recurrence was significantly higher at 5 y in patients with persistent lymphopenia (43%) compared with those who recovered (14% P = 0.0017) and those who never dropped (0% P = 0.0009). The persistent lymphopenia group had significantly lower survival (45%) compared with the two other groups (67% P = 0.0232). CONCLUSIONS: There is a significant decrease in the overall and recurrence-free survival in those patients whose lymphocyte count drops without recovery after their esophagectomy. These data imply differences in immune responses to the stress of surgery that can be measured with routine postoperative laboratory values and are indicative of overall outcomes.

Biologics Delay Progression of Crohn's Disease, but Not Early Surgery, in Children.

BACKGROUND & AIMS: Up to 30% of patients with Crohn's disease (CD) require surgery within the first 5 years from diagnosis. We investigated the recent risk of bowel surgery in an inception cohort of pediatric patients with CD and whether early use of biologics (tumor necrosis factor antagonists) alters later disease course. METHODS: We collected data from the Pediatric Inflammatory Bowel Disease Collaborative Research Group registry on 1442 children (age, ≤16 y) diagnosed with CD from January 2002 through December 2014. Data were collected at diagnosis, 30 days following diagnosis, and then quarterly and during hospitalizations for up to 12 years. Our primary aim was to determine the 10-year risk for surgery in children with CD. Our secondary aim was to determine whether early use of biologics (<3 mo of diagnosis) affected risk of disease progression. RESULTS: The 10-year risk of first bowel surgery was 26%. The 5-year risk of bowel surgery did not change from 2002 through 2014, and remained between 13% and 14%. Most surgeries occurred within 3 years from diagnosis. The only predictor of surgery was disease behavior at diagnosis. CD with inflammatory behavior had the lowest risk of surgery compared to stricturing disease, penetrating disease, or both. We associated slowing of disease progression to stricturing or penetrating disease (but not surgery) with early use of biologics, but this effect only became evident after 5 years of disease. Our results indicate that biologics slow disease progression over time (hazard ratio, 0.85; 95% CI, 0.76-0.95). CONCLUSIONS: In an analysis of data from a registry of pediatric patients with CD, we found that among those with significant and progressing disease at or shortly after presentation, early surgery is difficult to prevent, even with early use of biologics. Early use of biologics (<3 mo of diagnosis) can delay later disease progression to stricturing and/or penetrating disease, but this affect could become evident only years after initial management decisions are made.

Role of immune microenvironment in gastrointestinal stromal tumours.

AIMS: The immune microenvironment is a prognostic factor for various malignancies. The significance of key players of this immune microenvironment, including tumour-infiltrating lymphocytes (TILs) and expression of programmed death-ligand 1 (PD-L1), indoleamine 2,3-dioxygenase (IDO) and tryptophanyl-tRNA synthetase (WARS) in gastrointestinal stromal tumours (GISTs) is largely unknown. METHODS AND RESULTS: Tissue microarrays were constructed from pathology files, 1996-2016. Immunohistochemistry for PD-L1, IDO and WARS was correlated with tumour size, mitoses and outcomes. TILs expressing CD3, CD4, CD8, FoxP3 and GBP5 were counted. A total of 129 GISTs were analysed. Mean patient age was 62.5 years; 52.0% were male. Tumour location included 89 stomach (69.0%), 33 small bowel (25.6%) and seven other (5.4%). Mean tumour size was 5.6 cm; mean mitoses were 7.2 per 50 high-power field. Nineteen patients (15.0%) developed disease progression, to abdominal wall (n = 8), liver (n = 6) and elsewhere (n = 5). Median progression-free survival was 56.6 months; five patients died of disease. PD-L1 was positive in 88 of 127 tumour samples (69.0%), 114 of 127 tumours were IDO-positive (89.8%) and 60 of 127 were positive for WARS (47.2%). PD-L1 was associated with increased size (P = 0.01), necrosis (P = 0.018) and mitoses (P = 0.006). Disease progression was not associated with PD-L1 (P = 0.44), IDO (P = 0.14) or WARS (P = 0.36) expression. PD-L1-positive GISTs with CD8+ or CD3+ TILs were significantly smaller than tumours with CD8+ or CD3+ TILs. CONCLUSIONS: PD-L1 expression was associated with increased size and mitoses. High CD8+ or CD3+ TIL counts were associated with decreased PD-L1/IDO+ GIST size. PD-L1 and IDO could be significant in GIST tumour biology, which invites consideration of immunotherapy as a potential treatment option.

Expression of PD-L1, indoleamine 2,3-dioxygenase and the immune microenvironment in gastric adenocarcinoma.

AIMS: The tumour microenvironment is increasingly important in several tumours. We studied the relationship of key players of immune microenvironment with clinicopathological parameters in gastric adenocarcinomas. METHODS AND RESULTS: Tissue microarrays were constructed from gastrectomy specimens, 2004-13. Immunohistochemistry was performed for programmed cell death ligand 1 (PD-L1), indoleamine 2,3-dioxygenase (IDO), tryptophanyl-tRNA synthetase (WARS), guanylate-binding protein 5 (GBP5), tumour-infiltrating lymphocytes (TIL) expressing CD3/CD8/FoxP3/PD1 and mismatch repair proteins (MMRs) MLH1, PMS2, MSH2 and MSH6. Clinicopathological parameters and clinical follow-up were recorded. The study included 86 patients; median follow-up was 34 months (0-148). Tumour types were 45% tubular, 38% diffuse, 17% mixed. PD-L1 was positive in 70%, epithelial IDO in 58%, stromal IDO in 91%, epithelial WARS in 67%, stromal WARS in 100%, epithelial GBP5 in 53% and stromal GBP5 in 71%. MMR-deficiency was found in 22%. There was no difference in biomarker expression by histological subtype, with the exception of fewer diffuse-type being MMR-deficient. Low stromal IDO was associated with decreased progression-free, overall and disease-specific survival. PD-L1-positive tumours were larger with MMR-deficiency and with increasing TILs, and had significantly higher FoxP3TILs. CONCLUSIONS: PD-L1 is expressed in a large proportion of gastric carcinomas, suggesting that therapy targeting this pathway could be relevant to many patients. PD-L1 expression and MMR-deficiency are associated with increased TILs and larger tumour size, emphasising their role in tumour biology. Higher stromal IDO expression is associated with better prognosis. Finally, we observed that immune modulators WARS and GBP5 are expressed highly in gastric adenocarcinomas, suggesting an important role in tumour pathobiology.

Cluster reduction in patients in a pilot treatment trial for psychogenic nonepileptic seizures.

INTRODUCTION: The present study examined seizure clusters as a primary outcome in patients receiving treatment for PNES. Cluster reduction is examined longitudinally using frequency threshold and statistical definitions of seizure cluster for patients. Possible risk factors for clustering will be examined along with clustering as a risk factor for poorer secondary outcomes. METHODS: Participants were from a pilot randomized treatment trial for PNES where they received cognitive behavioral therapy-informed psychotherapy (CBT-ip), sertraline, combination therapy, or treatment as usual. Seizure data are from patients' seizure dairies. RESULTS: Cluster reduction was observed for those receiving CBT-ip or combination treatment using all definitions of daily clusters and weekly clusters. No risk factors of clustering were observed. Those who were identified as having clusters during the trial had poorer secondary outcomes on several measures at baseline relative to those who were not identified as having clusters. DISCUSSION: This is the first study known to the authors to not only examined seizure clusters as a primary outcome for those with PNES, but also the first study to suggest that CBT-ip and combination therapy may be effective in reducing the frequency of clusters.

Identifying seizure clusters in patients with psychogenic nonepileptic seizures.

The present study explored how seizure clusters may be defined for those with psychogenic nonepileptic seizures (PNES), a topic for which there is a paucity of literature. The sample was drawn from a multisite randomized clinical trial for PNES; seizure data are from participants' seizure diaries. Three possible cluster definitions were examined: 1) common clinical definition, where ≥3 seizures in a day is considered a cluster, along with two novel statistical definitions, where ≥3 seizures in a day are considered a cluster if the observed number of seizures statistically exceeds what would be expected relative to a patient's: 1) average seizure rate prior to the trial, 2) observed seizure rate for the previous seven days. Prevalence of clusters was 62-68% depending on cluster definition used, and occurrence rate of clusters was 6-19% depending on cluster definition. Based on these data, clusters seem to be common in patients with PNES, and more research is needed to identify if clusters are related to triggers and outcomes.

Effect of Fecal Microbiota Transplantation on Recurrence in Multiply Recurrent Clostridium difficile Infection: A Randomized Trial.

BACKGROUND: To date, evidence for the efficacy of fecal microbiota transplantation (FMT) in recurrent Clostridium difficile infection (CDI) has been limited to case series and open-label clinical trials. OBJECTIVE: To determine the efficacy and safety of FMT for treatment of recurrent CDI. DESIGN: Randomized, controlled, double-blind clinical trial. (ClinicalTrials.gov: NCT01703494). SETTING: Two academic medical centers. PATIENTS: 46 patients who had 3 or more recurrences of CDI and received a full course of vancomycin for their most recent acute episode. INTERVENTION: Fecal microbiota transplantation with donor stool (heterologous) or patient's own stool (autologous) administered by colonoscopy. MEASUREMENTS: The primary end point was resolution of diarrhea without the need for further anti-CDI therapy during the 8-week follow-up. Safety data were compared between treatment groups via review of adverse events (AEs), serious AEs (SAEs), and new medical conditions for 6 months after FMT. Fecal microbiota analyses were performed on patients' stool before and after FMT and also on donors' stool. RESULTS: In the intention-to-treat analysis, 20 of 22 patients (90.9%) in the donor FMT group achieved clinical cure compared with 15 of 24 (62.5%) in the autologous FMT group (P = 0.042). Resolution after autologous FMT differed by site (9 of 10 vs. 6 of 14 [P = 0.033]). All 9 patients who developed recurrent CDI after autologous FMT were free of further CDI after subsequent donor FMT. There were no SAEs related to FMT. Donor FMT restored gut bacterial community diversity and composition to resemble that of healthy donors. LIMITATION: The study included only patients who had 3 or more recurrences and excluded those who were immunocompromised and aged 75 years or older. CONCLUSION: Donor stool administered via colonoscopy seemed safe and was more efficacious than autologous FMT in preventing further CDI episodes. PRIMARY FUNDING SOURCE: National Institute of Diabetes and Digestive and Kidney Diseases.

Arthroscopic Quantification of Syndesmotic Instability in a Cadaveric Model.

PURPOSE: To investigate whether arthroscopy or stress radiography can identify instability resulting from single-ligament injury of the ankle syndesmosis and to determine whether either modality is capable of differentiating between various levels of ligament injury. METHODS: Syndesmotic/deltoid ligament sectioning was performed in 10 cadaver legs. Arthroscopic evaluation and fluoroscopic stress testing were completed after each sectioning. In group 1 (n = 5), sectioning began with anteroinferior tibiofibular ligament (AITFL), then interosseous membrane (IOM), posteroinferior tibiofibular ligament (PITFL), and deltoid. In group 2 (n = 5), this order was reversed. Measurements were made by determining the largest-sized probe that would fit in the anterior and posterior syndesmosis. Radiographic parameters included tibiofibular overlap/clear space and medial clear space. RESULTS: No radiographic measurement proved useful in distinguishing between intact and transected AITFL. Anterior probe (AP) size reached significance when distinguishing between intact and AITFL-transected specimens (P < .0001). AP detected significant differences comparing single with 2-, 3-, and 4-ligament (AITFL, IOM, PITFL, deltoid) disruptions (P = .05, <.0001, and <.0001, respectively). Significant differences were observed between 2- and 3/4-ligament (P = .02) transections. Posterior probe (PP) size detected significant differences between intact and single-, double-, triple-, and complete ligament transections (P values .0006, <.0001, <.0001, <.001, respectively). PP detected significant differences between single- and double-, triple-, and complete ligament transection models (P = .0075, .0010, and .0010, respectively). PP distinguished between 2- and 3/4-ligament (P = .03) transections. CONCLUSIONS: Stress radiography did not distinguish between intact and single-ligament disruption, and was unreliable in distinguishing between sequential transection models. Arthroscopy significantly predicted isolated disruption of the AITFL or deltoid ligaments. Also, probing was able to differentiate between most patterns of ligament injury, including sequential transections. CLINICAL RELEVANCE: These data can aid surgeons during arthroscopy of the ankle when attempting to correlate intraoperative syndesmotic evaluation findings with the extent of ligament injury.

Effectiveness and safety of computed tomography-guided radiofrequency ablation of renal cancer: a 14-year single institution experience in 203 patients.

OBJECTIVES: To define effectiveness and safety of CT-guided radiofrequency ablation (RFA) of renal tumours and prognostic indicators for treatment success. METHODS: Patients with a single treatment of a solitary, biopsy-proven renal tumour with intent to cure over a 14-year period were included (n = 203). Probability of residual disease over time, complication rates and all-cause mortality were assessed in relation to multiple variables. RESULTS: Mean tumour size was 2.5 cm (range 1.0-6.0). Mean follow-up was 34.1 months (range 1-131). There was an increase in likelihood of residual disease for tumours ≥3.5 cm (P < 0.05), clear cell subtype of renal cell carcinoma (P ≤ 0.005) and maximum treatment temperature ≤70 °C (P < 0.05). There was a decrease in likelihood of residual disease for exophytic tumours (P = 0.01) and no difference based on age, gender, tumour location or type of radio freqency (RF) electrode used. Major complications occurred in 3.9 %. Median post-treatment survival was 7 years for patients with tumours <4 cm, and 5-year overall survival was 80 %. Probability of minor complication increased with tumour size (P = 0.03), as did all-cause mortality (P = 0.005). CONCLUSIONS: CT-guided RFA is safe and effective for early-stage renal cancer, particularly for exophytic tumours measuring <3.5 cm. Overall 5-year survival with tumours <4 cm is comparable to partial nephrectomy. KEY POINTS: • Prognostic indicators for success of CT-guided RFA of renal tumours are reported. • Tumour size ≥3.5 cm confers an increased risk for residual tumour. • Clear cell renal cell carcinoma subtype confers increased risk for residual tumour. • Tmax <70 °C within the ablation zone confers increased risk for residual tumour. • Exophytic tumours have a lower probability of residual disease.

A High Rate of Alternative Diagnoses in Patients Referred for Presumed Clostridium difficile Infection.

GOALS: We evaluated a cohort of patients referred to our center for presumed recurrent Clostridium difficile infection (CDI) to determine final diagnoses and outcomes. BACKGROUND: As rates of CDI have increased, more patients are diagnosed with recurrent CDI and other sequelae of the infection. Distinguishing symptomatic patients with CDI from those who are colonized with an alternative etiology of diarrheal symptoms may be challenging. MATERIALS AND METHODS: We performed a retrospective review of 117 patients referred to our center for recurrent CDI between January 2013 and June 2014. Data collected included demographics, the referring provider, previous anti-CDI treatment, and significant medical conditions. In addition, we gathered data on atypical features of CDI and investigations obtained to investigate the etiology of symptoms. Outcomes included rates of alternative diagnoses and the accuracy of CDI diagnosis by the referral source. RESULTS: The mean age was 61 years, and 70% were female. About 29 patients (25%) were determined to have a non-CDI diagnosis. Most common alternative diagnoses included irritable bowel syndrome (18 patients: 62%) and inflammatory bowel disease (3 patients:10%). The age was inversely correlated with the rate of non-CDI diagnosis (P=0.016). Of the remaining 88 (75%) patients with a confirmed diagnosis of CDI, 25 (28%) received medical therapy alone and 63 (72%) underwent fecal microbiota transplantation. CONCLUSIONS: Among patients referred to our center for recurrent CDI, a considerable percentage did not have CDI, but rather an alternative diagnosis, most commonly irritable bowel syndrome. The rate of alternative diagnosis correlated inversely with age. Providers should consider other etiologies of diarrhea in patients presenting with features atypical of recurrent CDI.

Durability of Infliximab Is Associated With Disease Extent in Children With Inflammatory Bowel Disease.

OBJECTIVES: The aim of the study was to evaluate infliximab (IFX) dosing and treatment durability relative to luminal disease burden in patients with inflammatory bowel disease. METHODS: Records from 98 pediatric patients treated with IFX between 2012 and 2014 were reviewed. Disease extent was classified as "limited," "moderate," or "extensive" based on cumulative assessment of mucosal involvement. Patients started taking standard 5 mg/kg dosing were compared with those initiated taking 10 mg/kg with regard to treatment durability. RESULTS: Overall, 26.4%, 58.3%, and 70% with limited, moderate, or extensive disease, respectively, started taking a standard IFX dose of 5 mg/kg required therapy escalation. Patients with moderate and extensive disease, started taking the 5 mg/kg per dose, showed statistically significant shorter times to escalation than those with limited disease. The percentage of patients remaining on their initial 5 mg/kg per dose at 12 months was 80.1%, 56.9%, and 40.0% for limited, moderate, and extensive disease, respectively. Among patients started taking 10 mg/kg, 100% remained on this dose. All the patients with limited disease who required dose escalation continued on the higher dose at the time of analysis; however, among those with the most extensive disease, 43% failed escalation because of nonresponse or infusion reaction. CONCLUSIONS: Patients with extensive disease started taking 5 mg/kg of IFX were more likely to require dose escalation compared to those with limited or moderate disease. All of the patients with moderate and extensive disease started taking 10 mg/kg of IFX remained on this dose. These results suggest that patients with more extensive disease may benefit from higher initial IFX dosing as it relates to durability of the treatment.

Infant sleep and feeding patterns are associated with maternal sleep, stress, and depressed mood in women with a history of major depressive disorder (MDD).

Our goal was to examine associations of infant sleep and feeding patterns with maternal sleep and mood among women at risk for postpartum depression. Participants were 30 women (age ± SD = 28.3 ± 5.1 years) with a history of MDD (but not in a mood episode at enrollment) who completed daily sleep diaries, wore wrist actigraphs to estimate sleep, and had their mood assessed with the Hamilton Depression Rating Scale (HAM-D-17) during four separate weeks of the perinatal period (33 weeks pregnancy and weeks 2, 6, and 16 postpartum). They logged their infants' sleep and feeding behaviors daily and reported postnatal stress on the Childcare Stress Inventory (CSI) at week 16. Mothers' actigraphically estimated sleep showed associations with infant sleep and feeding patterns only at postpartum week 2. Shorter duration of the longest infant-sleep bout was associated with shorter maternal sleep duration (p = .02) and lower sleep efficiency (p = .04), and maternal sleep efficiency was negatively associated with the number of infant-sleep bouts (p = .008) and duration of infant feeding (p = .008). Neither infant sleep nor feeding was associated with maternal sleep at 6 or 16 weeks, but more disturbed infant sleep and more frequent feeding at 6 weeks were associated with higher HAM-D scores at 6 and 16 weeks and higher CSI scores. Sleep in the mother-infant dyad is most tightly linked in the early postpartum weeks, but mothers continue to experience disturbed sleep and infant sleep and feeding behaviors continue to be associated with mothers' depressive symptoms and stress ratings as long as 16 weeks postpartum. These data imply that interventions designed to improve maternal sleep and postpartum mood should include both mothers and infants because improving infant sleep alone is not likely to improve maternal sleep, and poor infant sleep is linked to postpartum depression and stress.

Increased Prevalence of Optic Disc Drusen after Papilloedema from Idiopathic Intracranial Hypertension: On the Possible Formation of Optic Disc Drusen.

This is a 25-year observational retrospective review of 372 consecutive participants with optic disc drusen or resolved papilloedema from idiopathic intracranial hypertension. The prevalence of optic disc drusen at 19% among eyes with resolved papilloedema was approximately 10 times higher and significantly increased (p < 0.001) as compared with the occurrence in the general population. Eyes with both resolved papilloedema and optic disc drusen had similar visual acuity and visual field outcome as compared with resolved papilloedema alone. Eyes with exposed drusen had significantly worse visual acuity and visual field outcome (p < 0.001) than buried drusen. The high prevalence of optic disc drusen after papilloedema has resolved suggests a non-coincidental relationship. Optic disc drusen formation can be a sequela of papilloedema.

Racial Differences in Clostridium difficile Infection Rates Are Attributable to Disparities in Health Care Access.

This study confirms previously reported racial differences in Clostridium difficile infection (CDI) rates in the United States and explores the nature of those differences. We conducted a retrospective study using the 2010 Nationwide Inpatient Sample, the largest all-payer database of hospital discharges in the United States. We identified hospital stays most likely to include antibiotic treatment for infections, based on hospital discharge diagnoses, and we examined how CDI rates varied, in an attempt to distinguish between genotypic and environmental racial differences. Logistic regressions for the survey design were used to test hypotheses. Among patients likely to have received antibiotics, white patients had higher CDI rates than black, Hispanic, Asian, and Native American patients (P < 0.0001). CDI rates increased with higher income levels and were higher for hospitalizations paid by private insurance versus those paid by Medicaid or classified as self-pay or free care (P < 0.0001). Among patients admitted from skilled nursing facilities, where racial bias in health care access is less, racial differences in CDI rates disappeared (P = 1.0). Infected patients did not show racial differences in rates of complicated CDI or death (P = 1.0). Although white patients had greater CDI rates than nonwhite patients, racial differences in CDI rates disappeared in a population for which health care access was presumed to be less racially biased. This provides evidence that apparent racial differences in CDI risks may represent health care access disparities, rather than genotypic differences. CDI represents a deviation from the paradigm that increased health care access is associated with less morbidity.

Arterial Catheter Use in the ICU: A National Survey of Antiseptic Technique and Perceived Infectious Risk.

OBJECTIVES: Recent studies have shown that the occurrence rate of bloodstream infections associated with arterial catheters is 0.9-3.4/1,000 catheter-days, which is comparable to that of central venous catheters. In 2011, the Centers for Disease Control and Prevention published new guidelines recommending the use of limited barrier precautions during arterial catheter insertion, consisting of sterile gloves, a surgical cap, a surgical mask, and a small sterile drape. The goal of this study was to assess the attitudes and current infection prevention practices used by clinicians during insertion of arterial catheters in ICUs in the United States. DESIGN: An anonymous, 22-question web-based survey of infection prevention practices during arterial catheter insertion. SETTING: Clinician members of the Society of Critical Care Medicine. SUBJECTS: Eleven thousand three hundred sixty-one physicians, nurse practitioners, physician assistants, respiratory therapists, and registered nurses who elect to receive e-mails from the Society of Critical Care Medicine. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: There were 1,265 responses (11% response rate), with 1,029 eligible participants after exclusions were applied. Only 44% of participants reported using the Centers for Disease Control and Prevention-recommended barrier precautions during arterial catheter insertion, and only 15% reported using full barrier precautions. The mean and median estimates of the incidence density of bloodstream infections associated with arterial catheters were 0.3/1,000 catheter-days and 0.1/1,000 catheter-days, respectively. Thirty-nine percent of participants reported that they would support mandatory use of full barrier precautions during arterial catheter insertion. CONCLUSIONS: Barrier precautions are used inconsistently by critical care clinicians during arterial catheter insertion in the ICU setting. Less than half of clinicians surveyed were in compliance with current Centers for Disease Control and Prevention guidelines. Clinicians significantly underestimated the infectious risk posed by arterial catheters, and support for mandatory use of full barrier precautions was low. Further studies are warranted to determine the optimal preventive strategies for reducing bloodstream infections associated with arterial catheters.

Increased platelet concentration does not improve functional graft healing in bio-enhanced ACL reconstruction.

PURPOSE: The use of an extracellular matrix scaffold (ECM) combined with platelets to enhance healing of an anterior cruciate ligament (ACL) graft ("bio-enhanced ACL reconstruction") has shown promise in animal models. However, the effects of platelet concentration on graft healing remain unknown. The objectives of this study were to determine whether increasing the platelet concentration in the ECM scaffold would (1) improve the graft biomechanical properties and (2) decrease cartilage damage after surgery. METHODS: Fifty-five adolescent minipigs were randomized to five treatment groups: untreated ACL transection (n = 10), conventional ACL reconstruction (n = 15) and bio-enhanced ACL reconstruction using 1× (n = 10), 3× (n = 10) or 5× (n = 10) platelet-rich plasma. The graft biomechanical properties, anteroposterior (AP) knee laxity, graft histology and macroscopic cartilage integrity were measured at 15 weeks. RESULTS: The mean linear stiffness of the bio-enhanced ACL reconstruction procedure using the 1× preparation was significantly greater than traditional reconstruction, while the 3× and 5× preparations were not. The failure loads of all the ACL-reconstructed groups were equivalent but significantly greater than untreated ACL transection. There were no significant differences in the Ligament Maturity Index or AP laxity between reconstructed knees. Macroscopic cartilage damage was relatively minor, though significantly less when the ECM-platelet composite was used. CONCLUSIONS: Only the 1× platelet concentration improved healing over traditional ACL reconstruction. Increasing the platelet concentration from 1× to 5× in the ECM scaffold did not further improve the graft mechanical properties. The use of an ECM-platelet composite decreased the amount of cartilage damage seen after ACL surgery.

Small-fiber degeneration in alcohol-related peripheral neuropathy.

BACKGROUND: Alcohol-related peripheral neuropathy (ALN) is generally characterized as an axonal large-fiber polyneuropathy caused by thiamine deficiency. We hypothesized, based on clinical observations, that ALN is associated with a small-fiber polyneuropathy that can be diagnosed with skin biopsy in heavy alcohol drinking subjects with normal thiamine status. METHODS: Eighteen individuals (9 heavy alcohol drinking subjects and 9 healthy control subjects) were assessed for the potential utility of skin biopsies in detecting ALN-associated small nerve fiber degeneration. Heavy drinking was defined as greater than 4 drinks/d and 5 drinks/d in women and men, respectively, as determined by the Timeline Follow-Back and lifetime drinking history. All subjects underwent neurological examination, nerve conduction studies, and skin biopsies to quantify end nerve fiber densities (ENFD). Other causes of neuropathy were excluded and thiamine status was assessed. RESULTS: Average ENFD were significantly decreased at the calf in the alcohol group as compared with control group (p < 0.0001). Histological sections demonstrated striking attrition and architectural simplification of intraepidermal nerve fibers in the heavy alcohol drinking subjects. There were no significant intergroup differences with respect to clinical assessments of neuropathy or thiamine status. CONCLUSIONS: ALN is associated with a small-fiber neuropathy that can be detected with skin biopsy in heavy alcohol drinking individuals with normal thiamine status. Skin biopsy is a useful, minimally invasive biomarker that could extend studies to understand the effect of alcohol on the peripheral nerves and to evaluate potential therapeutic agents in larger clinical trials.

A pilot study estimating liver fibrosis with ultrasound shear-wave elastography: does the cause of liver disease or location of measurement affect performance?

OBJECTIVE: The purpose of this study was to evaluate the diagnostic accuracy of real-time shear-wave elastography for assessment of liver fibrosis in an unselected patient population, comparing shear-wave elastography measurements obtained at and remote from the site of random liver biopsy. SUBJECTS AND METHODS: In a prospective study of 50 patients (21 with and 29 without hepatitis C) referred for clinically indicated random liver biopsy for diffuse liver disease, shear-wave elastography measurements were taken from four locations before biopsy: one at the left lobe, two at the right lobe, and one at the biopsy location. The mean, minimum, maximum, and SD of shear-wave elastography were compared with pathologic grading. Steatosis and serum markers were analyzed using multiple logistic regression. Optimized shear-wave elastography thresholds were calculated using AUC analysis. RESULTS: The AUC (95% CI) at the biopsy site, ipsilateral lobe, and contralateral lobe were 0.82 (0.63-1.0), 0.84 (0.67-1.0), and 0.59 (0.19-0.99) in hepatitis C patients; 0.89 (0.75-1.0), 0.88 (0.73-1.0), and 0.93 (0.80-1.0) in nonhepatitis C patients; and 0.85 (0.74-0.96), 0.89 (0.79-0.99), and 0.80 (0.67-0.93) in all patients, respectively. Optimized biopsy site shear-wave elastography values for detecting Metavir score F2 or greater were 1.87 m/s (75% sensitivity and specificity), 2.00 m/s (80% sensitivity and specificity), and 1.89 m/s (76% sensitivity and specificity) in hepatitis C, nonhepatitis C, and all patients, respectively. Steatosis and serum markers were not significant. CONCLUSION: Real-time shear-wave elastography accurately predicted significant fibrosis (stage ≥ 2) in an unselected patient population with diffuse disease, including patients with and without hepatitis C. Shear-wave elastography best predicts pathologic grading when taken at the biopsy site or ipsilateral lobe in hepatitis C patients. Percentage steatosis was not predictive of shear-wave elastography results.

Evaluating the hematoma block as an adjunct to procedural sedation for closed reduction of distal forearm fractures.

OBJECTIVES: Although procedural sedation using intravenous agents is highly effective for forearm fracture reduction, the process is both resource and time intensive. Our objective was to determine whether the use of a hematoma block as an adjunct to procedural sedation with ketamine and midazolam reduces (1) pain during the procedure (scored using the Observational Score for Behavioral Distress-Revised score) or (2) the excess sedation time, defined by the time between procedure completion and discharge from sedation. Our secondary outcome measure was total ketamine dose administered during the procedure. METHODS: A randomized, double-blind, placebo-controlled clinical trial was conducted. Before fracture reduction, children 3 to 17 years of age randomly received 2% lidocaine (L) or normal saline (NS) into the hematoma of their fracture site during sedation with intravenous ketamine and midazolam. RESULTS: Ninety patients were randomized: 50 to L and 40 to NS. The groups were similar with regard to age, sex, type of fracture, and prior administration of pain medication. Median Observational Score for Behavioral Distress-Revised scores were 1.11 and 1.69 for the L and NS groups, respectively (P = 0.23). Excess sedation time was not significantly different between the groups (P = 0.36), with a median excess sedation time of 33.0 and 36.0 minutes for the L and NS groups, respectively. Mean ketamine dose administered was not different between the groups (P = 0.42). The mean total dose administered was 1.00 mg/kg and 1.07 mg/kg in the L and NS groups, respectively. Mean midazolam dose was 0.05 mg/kg for both groups. CONCLUSIONS: The use of a hematoma block as an adjunct to procedural sedation with ketamine and midazolam for forearm fracture reduction conferred no additional benefit and did not decrease observed pain scores, excess sedation time, or total ketamine dose administered.