Increased core body temperature exacerbates defective protein prenylation in mouse models of mevalonate kinase deficiency

Mevalonate kinase deficiency (MKD) is characterized by recurrent fevers and flares of systemic inflammation, caused by biallelic loss-of-function mutations in MVK. The underlying disease mechanisms and triggers of inflammatory flares are poorly understood because of the lack of in vivo models. We describe genetically modified mice bearing the hypomorphic mutation p.Val377Ile (the commonest variant in patients with MKD) and amorphic, frameshift mutations in Mvk. Compound heterozygous mice recapitulated the characteristic biochemical phenotype of MKD, with increased plasma mevalonic acid and clear buildup of unprenylated GTPases in PBMCs, splenocytes, and bone marrow. The inflammatory response to LPS was enhanced in compound heterozygous mice and treatment with the NLRP3 inflammasome inhibitor MCC950 prevented the elevation of circulating IL-1β, thus identifying a potential inflammasome target for future therapeutic approaches. Furthermore, lines of mice with a range of deficiencies in mevalonate kinase and abnormal prenylation mirrored the genotype-phenotype relationship in human MKD. Importantly, these mice allowed the determination of a threshold level of residual enzyme activity, below which protein prenylation is impaired. Elevated temperature dramatically but reversibly exacerbated the deficit in the mevalonate pathway and the defective prenylation in vitro and in vivo, highlighting increased body temperature as a likely trigger of inflammatory flares.

Outcomes of nutritional interventions to treat dysphagia in esophageal cancer: a population-based study

Esophageal cancer (EC) is increasing in prevalence due to rising incidence and improved treatment strategies. Dysphagia is a significant morbidity in patients with EC requiring nutritional intervention. We sought to evaluate outcomes of nutritional interventions for EC patients hospitalized with dysphagia at a population level. The National Inpatient Sample (2002-2012) was utilized to include all adult inpatients (≥18 years of age) with EC and presence of dysphagia and stricture that underwent nutritional interventions including feeding tube (FT) placement, esophageal stenting, or parenteral nutrition (PN). Temporal trends were examined with multivariate analysis performed for mortality, length of stay (LOS), and cost of hospitalization. A total of 509,593 EC patients had 12,205 hospitalizations related to dysphagia. The hospitalization rates doubled over the study period (1.52% vs. 3.28%, p < 0.001). The most common nutritional intervention was FT (27%), followed by esophageal stenting (13%), and PN (11%). PN was more frequently associated with a diagnosis of sepsis (6.1%, p = 0.023) compared to FT (2.5%) or esophageal stenting (1.8%). Multivariate analysis demonstrated FT and esophageal stenting had comparable mortality (OR 1.06, 95% CI: 0.49, 2.32); however, PN was associated with higher mortality (OR 2.37, 95% CI: 1.22, 4.63), cost of hospitalization ($5,510, 95% CI: 2,262, 8,759), and LOS (2.13 days, 95% CI: 0.72, 3.54). This study shows that hospitalizations for EC with dysphagia and related nutritional interventions are increasing. As a single modality, parenteral nutrition should be avoided. Among our esophageal stent and FT population, further studies are necessary to determine adequate interventions based on disease stage.

Omission of preoperative esophageal manometry does not alter operative approach or postoperative dysphagia following laparoscopic paraesophageal hernia repair

Routine esophageal manometry for surgical planning before laparoscopic paraesophageal hernia (PEH) has been advocated in an effort to reduce the likelihood of postoperative dysphagia. The purpose of this study is to investigate whether omitting routine preoperative esophageal manometry is associated with a change in the type of fundoplication performed and with an increase in the incidence of postoperative dysphagia. A retrospective cohort study of consecutive patients with and without preoperative esophageal manometry undergoing PEH repair was performed between January 2011 and July 2014 at an academic medical center. Demographic and outcome data were collected in a prospective database. The primary outcome measures were the type of fundoplication performed and postoperative disease-specific quality-of-life (GERD-HRQL) dysphagia score. Secondary outcome measures were total GERD-HRQL score, proton pump inhibitor (PPI) use, and requirement for endoscopic dilation. One hundred twenty-five patients underwent laparoscopic PEH repair. Forty-seven (37%) patients had preoperative manometry and 79 (63%) did not. Patients who did not have manometry were older (67.9 ± 14.3 vs. 61.7 ± 13.5, P = 0.02), but the groups did not differ in terms of BMI, gender, PPI use, baseline GERD-HRQL dysphagia score, or baseline total GERD-HRQL score. Sixty-nine (87%) patients without manometry and 43 (93%) patients with manometry underwent a complete fundoplication (P = 0.55). At a median follow-up of 16 (4-44) months, the median GERD-HRQL dysphagia scores (0(0-1) vs. 0(0-1); P = 0.66) and total GERD-HRQL scores (3(1-8) vs. 4(0-8); P = 0.72) were equivalent between the groups. Equivalent proportion of patients without and with preoperative manometry used PPI (9% vs. 21%; P = 0.06) and required endoscopic dilation (6% vs. 6%; P = 0.99) in the postoperative period. Omission of routine preoperative manometry prior to laparoscopic PEH repair is not associated with a change in the type of fundoplication performed, an increased incidence of postoperative dysphagia, or an increased requirement for postoperative endoscopic dilation.

Management of Barrett's esophagus and early esophageal cancer: update on endoscopic treatment strategies

Barrett's esophagus represents the strongest known risk factor for developing esophageal adenocarcinoma. The traditional management strategy for identifying and managing Barrett's esophagus involves screening and endoscopic surveillance to identify early stage, curable carcinoma. Recently, endoscopic eradication therapy has emerged to achieve the complete eradication of Barrett's esophagus and intramucosal cancer to prevent the development of invasive cancer with lymphatic spread. Randomized trials have demonstrated the efficacy of these approaches to reduce the progression to cancer, and endoscopic eradication therapy has become the preferred treatment approach for patients with high-grade dysplasia, and may be utilized for management of low-grade dysplasia as well. Owing to excellent eradication rates and favorable side effect profile, radiofrequency ablation has emerged as the ablative strategy of choice for patients undergoing endoscopic eradication therapy.

MS2 Coliphage as a Surrogate for 2009 Pandemic Influenza A (H1N1) Virus (pH1N1) in Surface Survival Studies on N95 Filtering Facepiece Respirators

Research on influenza viruses regarding transmission and survival has surged in the recent years due to infectious emerging strains and outbreaks such as the 2009 Influenza A (H1N1) pandemic. MS2 coliphage has been applied as a surrogate for pathogenic respiratory viruses, such as influenza, as it's safe for personnel to handle and requires less time and labor to measure virus infectivity. However, direct comparisons to determine the effectiveness of coliphage as a surrogate for influenza virus regarding droplet persistence on personal protective equipment such as N95 filtering facepiece respirators (FFRs) are lacking. Persistence of viral droplets deposited on FFRs in healthcare settings is important to discern due to the potential risk of infection via indirect fomite transmission. The objective of this study was to determine if MS2 coliphage could be applied as a surrogate for influenza A viruses for studying persistence when applied to the FFRs as a droplet. The persistence of MS2 coliphage and 2009 Pandemic Influenza A (H1N1) Virus on FFR coupons in different matrices (viral media, 2% fetal bovine serum, and 5 mg ml-1 mucin) were compared over time (4, 12, 24, 48, 72, and 144 hours) in typical absolute humidity conditions (4.1 × 105 mPa [18°C/20% relative humidity (RH)]). Data revealed significant differences in viral infectivity over the 6-day period (H1N1- P <0.0001; MS2 - P <0.005), although a significant correlation of viral log10 reduction in 2% FBS (P <0.01) was illustrated. Overall, MS2 coliphage was not determined to be a sufficient surrogate for influenza A virus with respect to droplet persistence when applied to the N95 FFR as a droplet.

Persistence of the 2009 pandemic influenza A (H1N1) virus on N95 respirators

In the United States, the 2009 pandemic influenza A (H1N1) virus (pH1N1) infected almost 20% of the population and caused >200,000 hospitalizations and >10,000 deaths from April 2009 to April 2010. On 24 April 2009, the CDC posted interim guidance on infection control measures in health care settings explicitly for pH1N1 and recommended using filtering face respirators (FFRs) when in close contact with a suspected- or confirmed-to-be-infected individual, particularly when performing aerosol-generating procedures. The persistence and infectivity of pH1N1 were evaluated on FFRs, specifically N95 respirators, under various conditions of absolute humidity (AH) (4.1 × 10(5) mPa, 6.5 × 10(5) mPa, and 14.6 × 10(5) mPa), sample matrices (2% fetal bovine serum [FBS], 5 mg/ml mucin, and viral medium), and times (4, 12, 24, 48, 72, and 144 h). pH1N1 was distributed onto N95 coupons (3.8 to 4.2 cm(2)) and extracted by a vortex-centrifugation-filtration process, and the ability of the remaining virus to replicate was quantified using an enzyme-linked immunosorbent assay (ELISA) to determine the log10 concentration of the infectious virus per coupon. Overall, pH1N1 remained infectious for 6 days, with an approximately 1-log10 loss of virus concentrations over this time period. Time and AH both affected virus survival. We found significantly higher (P ≤ 0.01) reductions in virus concentrations at time points beyond 24 to 72 h (-0.52-log10 reduction) and 144 h (-0.74) at AHs of 6.5 × 10(5) mPa (-0.53) and 14.6 × 10(5) mPa (-0.47). This research supports discarding respirators after close contact with a person with suspected or confirmed influenza infection due to the virus's demonstrated ability to persist and remain infectious.

Recombinant vascular endothelial growth factor165 gene therapy improves anastomotic healing in an animal model of ischemic esophagogastrostomy

Proper anastomotic healing is dependent upon many factors including adequate blood flow to healing tissue. The aim of this study was to investigate the impact of vascular endothelial growth factor (VEGF(165)) transfection on anastomotic healing in an ischemic gastrointestinal anastomosis model. Utilizing an established opossum model of esophagogastrectomy followed by esophageal-gastric anastomosis, the gastric fundus was transfected with recombinant human vascular endothelial growth factor via direct injection of a plasmid-based nonviral delivery system. Twenty-nine animals were divided into three groups: two concentrations of VEGF and a control group. Outcomes included VEGF mRNA transcript levels, neovascularization, tissue blood flow, and anastomotic bursting pressure. To determine whether local injection resulted in a systemic effect, distant tissues were evaluated for VEGF transcript levels. Successful gene transfection was demonstrated by quantitative polymerase chain reaction analysis of anastomotic tissue, with significantly higher VEGF mRNA expression in treated animals compared to controls. At the gastric side of the anastomosis, there was significantly increased neovascularization, blood flow, and bursting pressure in experimental animals compared to controls. There were no differences in outcome measures between low- and high-dose VEGF groups; however, the high-dose group demonstrated increased VEGF mRNA expression across the anastomosis. VEGF production was not increased at distant sites in treated animals. In this animal model, VEGF gene therapy increased VEGF transcription at a healing gastrointestinal anastomosis without systemic VEGF upregulation. This treatment led to improved healing and strength of the acutely ischemic anastomosis. These findings suggest that VEGF gene therapy has the potential to reduce anastomotic morbidity and improve surgical outcomes in a wide array of patients.

Mediation of sulfur speciation by a black sea facultative anaerobe

Shewanella putrefaciens, a respiratory facultative anaerobe isolated from the Black Sea, can reduce thiosulfate, sulfite, and elemental sulfur to sulfide readily and quantitatively. This widespread and anaerobically versatile microorganism, which is incapable of reducing sulfate, uses oxidized sulfur intermediates as electron acceptors during the respiratory oxidation of organic matter. Because of its widespread distribution and abundance, it may play a significant role in sulfur and trace metal cycling in the Black Sea and in other marine and freshwater anaerobic environments.

Trends in the management of esophageal carcinoma based on provider volume: treatment practices of 618 esophageal surgeons

Controversy exists regarding optimal treatment practices for esophageal cancer. Esophagectomy has received focus as one of the index procedures for both hospital and surgical quality despite a relative paucity of controlled trials to define best practices. A survey was created to determine the degree of heterogeneity in the treatment of esophageal cancer among a diverse group of surgeons and to use high-volume (HV) (>/=15 cases/year) and low-volume (LV) (<15 cases/year) designations to discern specific differences in the management of esophageal cancer from the surgeon's perspective. Based on society rosters, surgeons (n = 4000) in the USA and 15 countries were contacted via mail and queried regarding their treatment practices for esophageal cancer using a 50-item survey instrument addressing demographics, utilization of neoadjuvant chemoradiotherapy, and choice of surgical approach for esophageal resection and palliation. There were 618 esophageal surgeons among respondents (n = 1447), of which 77 (12.5%) were considered HV. The majority of HV surgeons (87%) practiced in an academic setting and had cardiothoracic training, while most LV surgeons were general surgeons in private practice (52.3%). Both HV and LV surgeons favored the hand-sewn cervical anastomosis and the stomach conduit. Minimally invasive esophagectomy is performed more frequently by HV surgeons when compared with LV surgeons (P = 0.045). Most HV surgeons use neoadjuvant therapy for patients with nodal involvement, while LV surgeons are more likely to leave the decision to the oncologist. With a few notable exceptions, substantial heterogeneity exists among surgeons' management strategies for esophageal cancer, particularly when grouped and analyzed by case volume. These results highlight the need for controlled trials to determine best practices in the treatment of this complex patient population.

Laparoscopic ultrasound as the primary method for bile duct imaging during cholecystectomy

BACKGROUND

Intraoperative fluorocholangiography (IOC) has been the standard method for bile duct imaging during cholecystectomy. Laparoscopic ultrasound (LUS) has been evaluated as a possible alternative, but has been used less frequently. The authors examined the evolving use of these two methods to assess the relative utility of LUS as the primary method for routine bile duct imaging during laparoscopic cholecystectomy (LC).

METHODS

This study analyzed a prospective database containing 423 consecutive cholecystectomies performed by one attending surgeon in an academic medical center between 1995 and 2005.

RESULTS

Intraoperative bile duct imaging was performed in 371 (94%) of 396 LCs performed for cholelithiasis. As recorded, IOC was performed in 239 cases, LUS in 236 cases, and both in 104 cases. Choledocholithiasis was present in 50 patients (13%). Common bile duct stones (CBDS) were identified by LUS in 3% of the patients without preoperative indicators of CBDS, and in 10% of the patients with one or more indicators. As shown by the findings, LUS had a positive predictive value of 100%, a negative predictive value of 99.6%, a sensitivity of 92.3%, and a specificity of 100% for detecting CBDS. Also, LUS identified clinically significant bile duct anatomy in 6% of the patients. In 1995, LUS was used for 20% of cases, whereas by 2005, it was used for 97% of cases. Conversely, the use of IOC decreased from 93% to 23%.

CONCLUSIONS

With moderate experience, LUS can become the primary routine imaging method for evaluating the bile duct during LC. It is as reliable as IOC for detecting choledocholithiasis. In addition, LUS can locate the common bile duct during difficult dissections. On the basis of this experience, LUS is used currently in nearly all LCs and is the sole method for bile duct imaging in 75% of these cases. IOC is used as an adjunct to LUS when LUS imaging is inadequate, when stronger clinical indicators of choledocholithiasis are present, or when biliary anatomy remains uncertain.

Effects of Medicaid managed care on health care use: infant emergency department and ambulatory services

OBJECTIVE

Many urban children rely on emergency departments (ED) for ambulatory care. The objective of this study was to determine whether enrollment in Medicaid managed care (MMC) alters ED or other ambulatory care compared with fee-for-service Medicaid (FFSM).

METHODS

A prospective cohort study of infants born between May 1994 and April 1995 with a 6-month follow-up period was conducted in an urban, teaching hospital and surrounding ambulatory settings. A consecutive sample of 644 infants enrolled in MMC or FFSM was studied; 92% of eligible patients were enrolled, and 94% completed follow-up. The main outcome measures were 1) proportion of patients in each group visiting an ED, primary care practitioner (PCP), or specialist; 2) mean number of visits per group; and 3) ED reliance (EDR) defined as the proportion of all ambulatory visits occurring in an ED.

RESULTS

Fifty-six percent of MMC and 54% of FFSM patients visited an ED (relative risk: 1.03; 95% confidence interval [CI]: 0.83, 1.27). More MMC patients had a sick visit to their PCP (relative risk: 1.34; 95% CI: 1.03, 1.74); no difference in proportion with well-child or specialty visits was found. Although the mean number of total ambulatory, ED, and specialty visits was the same, MMC patients had fewer well-child and more sick visits to the PCP than FFSM patients (P =.01). EDR was 21% for both groups (P =.95). After adjustment for other factors in multivariate analysis, insurance status remained unassociated with EDR (adjusted odds ratio [OR]: 0.91; 95% CI: 0.56, 1.69). Factors associated with EDR included United States-born mother (OR: 5.34; 95% CI: 1.61, 17.68) and use of a hospital-based primary care physician (OR: 2.00; 95% CI: 1.34, 2.98). Variables that characterized infants who were less likely to be ED reliant included adequate maternal prenatal care (OR: 0.52; 95% CI: 0.34, 0.78) and having a mother who completed high school (OR: 0.67; 95% CI: 0.45, 0.99).

CONCLUSIONS

Enrollment in MMC did not alter ED usage patterns when compared with FFSM. Some variation in use of other ambulatory services was detected.

Diapering choices: a critical review of the issues

Careful consideration is needed to determine which diapering system may be best suited to an institution's or individual's needs. A critical review of five issues--skin care, infection control, other health-related concerns, environmental and safety aspects, and time/cost issues--reveals that: (a) superabsorbent paper diapers reduce the incidence and severity of diaper dermatitis and control the spread of infection in caregiving surroundings; (b) cloth and paper diapers have different effects on the environment and neither type of diaper is clearly superior to the other; and (c) the cost of disposable diapers and reusable commercial-laundered diapers may be comparable, although home-laundered diapers are least expensive if the caregiver's labor is not considered.

Simulated responses to intermittent lognormally distributed doses at variable dose rates

Two previously reported equations for low-LET radiation, R = DmI-n and R = D[a + b(lnI) + h(lnI)2], where the response (R) is expressed in terms of dose (D) and dose rate (I) and the other parameters are constants, were used to compute distributions of response to intermittent, low-level, lognormally distributed doses, administered at different dose rates. The simulations show that the means of the response distributions are affected by both the dose and dose rate distributions. Within certain ranges of their respective values, the influence of the dose and dose rate on the response are in opposite directions, and lead to similar response distributions for numerically different combinations of dose and dose rate. The resolution and mean values of response distributions, when based on nonlinear dose-response relationships, are also affected by dose fractionation.

Simulated responses to lognormally distributed continuous low radiation doses

Three previously reported equations, expressing response as a function of both dose and dose rate, for low LET radiation were used to compute distributions of response to continuous, low-level, lognormally distributed doses for populations of variable size up to 5000. The simulations show that, when the response is inversely dependent on dose rate, the mean of the response distribution can either increase or decrease with increasing exposure to radiation, depending on whether or not the dose-dependent term is the dominant one in an equation. In one equation, which defines the response as conjugated hydroperoxide formation in irradiated membranes, the magnitude of the dose-dependent term is reduced the most by superoxide dismutase, an enzymic inhibitor of free radical processes. This results in the means of response distributions decreasing with increasing dose from continuous, low-level radiation.