Association of klotho, bone morphogenic protein 6, and annexin A2 polymorphisms with sickle cell osteonecrosis

In patients with sickle cell disease, clinical complications including osteonecrosis can vary in frequency and severity, presumably due to the effects of genes that modify the pathophysiology initiated by the sickle mutation. Here, we examined the association of single nucleotide polymorphisms (SNPs) in candidate genes (cytokines, inflammation, oxidant stress, bone metabolism) with osteonecrosis in patients with sickle cell disease. Genotype distributions were compared between cases and controls using multiple logistic regression techniques. An initial screen and follow-up studies showed that individual SNPs and haplotypes composed of several SNPs in bone morphogenic protein 6, annexin A2, and klotho were associated with sickle cell osteonecrosis. These genes are important in bone morphology, metabolism, and vascular disease. Our results may provide insight into the pathogenesis of osteonecrosis in sickle cell disease, help identify individuals who are at high risk for osteonecrosis, and thus allow earlier and more effective therapeutic intervention.     

The perception of cancer risk in patients with prevalent Barrett's esophagus enrolled in an endoscopic surveillance program

BACKGROUND & AIMS: Patients with Barrett's esophagus (BE) have a risk of esophageal adenocarcinoma of approximately 0.5% per year. Patients may have difficulty understanding this risk. This study assessed the perceived risk of cancer in patients with BE, and correlated their risk estimates with their health care use behaviors. METHODS: We performed a survey of patients with BE participating in an endoscopic surveillance program at 2 sites: a university teaching hospital and a Veterans' Administration hospital. A questionnaire also elicited their demographics as well as their sources of health information. Health care behaviors, including physician visits and endoscopic surveillance behaviors, were assessed. Patients were classified as either overestimators or nonoverestimators of risk. Characteristics of overestimators, as well as health care use patterns, were assessed. RESULTS: One hundred eighteen patients met entry criteria, and 92 (78%) completed all the questionnaires. Sixty-eight percent of patients overestimated their 1-year risk of cancer, with a mean estimated 1-year cancer risk being 13.6%. The lifetime risk also was overestimated by 38% of patients. Patients who overestimated risk were more likely to be Veterans' Administration medical center patients, have more symptomatic reflux, and were more likely to use the Internet to get health care information. There was no significant difference in physician visits between overestimators and nonestimators (1.2 visits per year vs 1.0, P = .20), nor in endoscopy use (5.7 endoscopies per 5-year period vs 5.0, P = .42). CONCLUSIONS: The majority of patients with prevalent BE participating in an endoscopic surveillance program overestimated their chances of developing adenocarcinoma of the esophagus. Efforts to improve education of such patients with BE are warranted.     

Serum sodium and hydration status predict transplant-free survival independent of MELD score in patients with cirrhosis

Background and Aim: Serum sodium may have prognostic value in addition to the model for end‐stage liver disease (MELD) score for prediction of early mortality in patients listed for liver transplant. In patients with cirrhosis, over‐hydration is a common feature but its prognostic value has not been evaluated. This study examines the independent prognostic significance of MELD, serum sodium and hydration status on long‐term survival in patients with cirrhosis. Methods: Serum sodium and hydration (total body water as a percentage of fat‐free mass) were measured in 227 consecutive cirrhotic patients (146 male, 81 female; median age 49 years, range 19–73 years; median MELD score 13, range 6–36). Patients with hepatocellular carcinoma or listed for liver transplantation at the time of initial assessment were excluded. A competing risks Cox proportional hazards analysis was performed to evaluate the influence of MELD, sodium and hydration on risk of death or transplant. Results: Median follow‐up was 52 (range 4–93) months. Serum sodium and hydration were each associated with reduction in time to death or transplant on univariate analysis (sodium: hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.87–0.94, P < 0.0001; hydration: HR 1.20, 95% CI 1.10–1.30, P < 0.0001). On multivariate analysis, MELD, serum sodium and hydration were independently predictive of death or transplant (MELD: HR 1.12, 95% CI 1.06–1.19, P < 0.0001; sodium: HR 0.93, 95% CI 0.87–0.99, P = 0.04; hydration: HR 1.17, 95% CI 1.02–1.33, P = 0.02). Conclusions: In non‐waitlisted patients with cirrhosis, serum sodium is predictive of transplant or death independent of MELD score.     

Immunoenzymatic evaluation of serum IgE in onchocerciasis in Chiapas, Mexico

Concentrations of total serum IgE were measured by an immunoenzymatic assay (Phadezym-PRIST) in 60 mexican onchocerciasis patients. In order to detect IgE antibodies against adult Onchocerca volvulus antigens, separately six onchocerciasis sera were depleted of IgE antibodies by using a mixture of Onchocerca gutturosa, Ascaris suum and Fasciola hepatica antigenic extracts coupled with sepharose 4B. Additionally, the sera were incubated with an adult O. volvulus antigenic extract coupled with sepharose 4B. The differences found between the IgE levels before and after incubation with heterologous antigens show that the median IgE value against O. volvulus adults antigens varies between 20 and 65 percent of the total serum IgE.     

Low prevalence of VRE gastrointestinal colonization of hospitalized patients in Manitoba tertiary care and community hospitals

OBJECTIVE:

To determine the prevalence of vancomycin-resistant enterococci (VRE) bowel colonization in hospitalized patients in Manitoba who had stool specimens collected for Clostridium difficile toxin and/or culture testing.

DESIGN:

Two tertiary care and five community hospitals in Winnipeg and three rural Manitoba community hospitals participated in this study. From January 1 to December 31, 1997 stool specimens, one per patient, submitted to hospital microbiology laboratories for C difficile toxin and/or culture testing were screened for VRE on colistin-nalidixic acid-vancomycin (6 μg/mL) (CNAV) agar plates. The study was divided into six, eight-week intervals. Stool specimens received in the first two weeks of each eight week interval were screened for VRE.

MAIN RESULTS:

A total of 1408 stool specimens were submitted over the 48-week study period. Sixty-seven (4.8%) patients with VRE colonization of their lower gastrointestinal tract were identified. Three of the 67 (4.5%) VRE isolates were Enterococcus faecium, with the remaining 64 (95.5%) were Enterococcus gallinarum. The three vancomycin-resistant E faecium -VREF- (from two different Winnipeg hospitals) demonstrated the vanA genotype, and were resistant to vancomycin, teicoplanin and ampicillin. All three VREF isolates also demonstrated high level resistance to both gentamicin and streptomycin but were susceptible to quinuprisitin/dalfopristin and {"type":"entrez-nucleotide","attrs":{"text":"LY333328","term_id":"1257359838"}}LY333328.

CONCLUSION:

VRE colonization in hospitalized patients in Manitoba is infrequent and most commonly due to E gallinarum. The prevalence of VREF colonization in the patients studied was 0.2% (three of 1408).Key Words: Manitoba, Prevalence, Vancomycin-resistant enterococciVancomycin-resistant Enterococcus faecium (VREF) accounts for up to 65% of E faecium isolates in hospitalized patients across the United States and is endemic in many North American tertiary care institutions (1,2). The management of these infections presents a significant clinical challenge because species of the genus Enterococcus, and in particular E faecium, are frequently resistant to several antimicrobial agents (3). High level penicillin resistance, high level aminoglycoside resistance and most recently vancomycin resistance are emerging as significant concerns in the treatment of enterococcal infections. This has prompted the development and evaluation of new antimicrobial agents such as quinupristin/dalfopristin and {"type":"entrez-nucleotide","attrs":{"text":"LY333328","term_id":"1257359838"}}LY333328, a glycopeptide, which may offer activity against enterococci resistant to conventional therapy (2).VREF is not endemic in Manitoba hospitals, and infection with VREF is extremely rare (4). However, the prevalence of VREF lower gastrointestinal tract (GIT) carriage, which frequently precedes infection (5,6), is presently unknown for patients hospitalized in Manitoba. To determine whether the lack of VREF endemnicity correlated with an absence of lower GIT colonization, we assessed lower GIT carriage of VREF for patients hospitalized in 10 Manitoba hospitals from January 1 to December 31, 1997. Our study was consistent with Centers for Disease Control and Prevention guidelines (Atlanta, Georgia) that suggest surveillance programs for vancomycin-resistant enterococci (VRE) be undertaken on an intermittent basis in areas where VRE is not known to be endemic (6). Isolates of VREF identified were phenotypically and genotypically characterized, and tested for their susceptibilities against a panel of antimicrobial agents.     

Effects of therapeutic hypercapnia on mesenteric ischemia-reperfusion injury

Hypercapnic acidosis protects against direct lung injury in in vivo and ex vivo models, however, lung injury/acute respiratory distress syndrome commonly occurs after a nonpulmonary etiology. We investigated whether therapeutic hypercapnia (TH)-deliberate elevation of carbon dioxide (CO2) tension-would protect against lung injury after splanchnic ischemia-reperfusion injury in an in vivo model. TH was associated with preservation of lung mechanics, attenuation of protein leakage, and improved oxygenation compared with control conditions. Lung protection was therapeutic as well as prophylactic. Protection was dose-dependent, but inspired CO2 concentrations above 5.0% were associated with little additional lung protection. Before lung injury, increasing FICO2 resulted in a dose-dependent increase in PaO2. Lung protection with hypercapnia occurred despite pulmonary artery pressures that were greater than observed with normocapnia. Reperfusion increased lipid peroxidation (tissue 8-isoprostane concentration) in the bowel, liver, and lung, and caused histologically apparent bowel injury; however, none of these effects was altered by TH. Therefore, TH-induced by adding CO2 to inspired gas-provides consistent protection against lung injury in terms of lung permeability, oxygenation, and lung mechanics after mesenteric ischemia-reperfusion. These data further support the emerging evidence for ongoing physiologic study of TH at the bedside.     

Genetic factors are major determinants of phenotypic variability in a mouse model of the DiGeorge/del22q11 syndromes

The del22q11 syndrome is associated with a highly variable phenotype despite the uniformity of the chromosomal deletion that causes the disease in most patients. Df1/+ mice, which model del22q11, present with reduced penetrance of cardiovascular defects similar to those seen in deleted patients but not with other del22q11-like findings. The reduced penetrance of cardiovascular defects is caused by the ability of mutant embryos to recover from a fourth pharyngeal arch artery growth abnormality that is fully penetrant in early embryos. Here we show that genetic background has a major effect on penetrance of cardiovascular defects by affecting this embryonic recovery process. This effect could not be explained by allelic variation at the haploid locus, and it is likely to be caused by genetic modifiers elsewhere in the genome. We also show that genetic factors control extension of the Df1/+ phenotype to include thymic and parathyroid anomalies, establishing the Df1 mouse as a model for the genetic analysis of three major features of human del22q11 syndrome. We found that in Df1/+ mice, as in human patients, expression of the heart and thymic phenotypes are essentially independent from each other, suggesting that they may be controlled by different genetic modifiers. These data provide a framework for our understanding of phenotypic variability in patients with del22q11 syndrome and the tools for its genetic dissection.