Meta-analysis of the prognostic value of CpG island methylator phenotype in rectal cancer.

PURPOSE: The pathological and prognostic importance of CpG island methylator phenotype (CIMP) in rectal cancer, as a sub-population of colorectal cancer, is unknown. A meta-analysis was preformed to estimate the prognostic significance of CIMP in rectal cancer. METHODS: A systematic search was performed of PubMed, Embase, MEDLINE, PubMed Central, and Cochrane electronic databases for articles pertaining to CIMP and rectal cancer. Articles were analysed and data extracted according to PRISMA standards. RESULTS: Six studies including 1529 patients were included in the analysis. Following dichotomisation, the prevalence of CIMP-positive tumours was 10 to 57%, with a median of 12.5%. Meta-analysis demonstrated the pooled odds ratio for all-cause death for CIMP-positive tumours vs CIMP-negative tumours was 1.24 (95% CI 0.88-1.74). Z test for overall effect was 1.21 (p = 0.23). Heterogeneity between the studies was low (X2 5.96, df 5, p = 0.31, I2 = 16%). A total of 15 different loci were used for assessing CIMP across the studies, with a median of 6.5 loci (range 5-8). CONCLUSIONS: No significant association between CIMP and poor outcomes in rectal cancer was demonstrated. There was a high degree of heterogeneity in CIMP assessment methodologies and in study populations. Rectal cancer datasets were frequently not extractable from larger colorectal cohorts, limiting analysis.

Evaluation of engraftment and immunological tolerance after reduced intensity conditioning in a rhesus hematopoietic stem cell gene therapy model.

Reduced intensity conditioning (RIC) is desirable for hematopoietic stem cell (HSC) targeted gene therapy; however, RIC may be insufficient for efficient engraftment and inducing immunological tolerance to transgenes. We previously established long-term gene marking in our rhesus macaque autologous HSC transplantation model following 10 Gy total body irradiation (TBI). In this study, we evaluated RIC transplantation with 4 Gy TBI in two rhesus macaques that received equal parts of CD34(+) cells transduced with green fluorescent protein (GFP)-expressing lentiviral vector and empty vector not expressing transgenes. In both animals, equivalently low gene marking between GFP and empty vectors was observed 6 months post-transplantation, even with efficient transduction of CD34(+) cells in vitro. Autologous lymphocyte infusion with GFP marking resulted in an increase of gene marking in lymphocytes in a control animal with GFP tolerance, but not in the two RIC-transplanted animals. In vitro assays revealed strong cellular and humoral immune responses to GFP protein in the two RIC-transplanted animals, but this was not observed in controls. In summary, 4 Gy TBI is insufficient to permit engraftment of genetically modified HSCs and induce immunological tolerance to transgenes. Our findings should help in the design of conditioning regimens in gene therapy trials.

Acute induction of human IL-8 production by intestinal epithelium triggers neutrophil infiltration without mucosal injury.

AIM: Neutrophil migration in the intestine depends on chemotaxis of neutrophils to CXC chemokines produced by epithelial cells. The goal of this project was to determine if acute induction of a CXC chemokine gradient originating from intestinal epithelial cells is sufficient to induce neutrophil influx into intact intestinal tissue. METHODS AND RESULTS: The authors developed a double transgenic mouse model with doxycycline induced human IL-8 expression restricted to intestinal epithelial cells. Doxycycline treatment of double transgenic mice for three days resulted in a 50-fold increase in the caecal IL-8 concentration and influx of neutrophils into the lamina propria. Although neutrophils entered the paracellular space between epithelial cells, complete transepithelial migration was not observed. Doxycycline treatment also increased the water content of the caecal and colonic stool, indicating dysfunctional water transport. However, the transmural electrical resistance was not decreased. Neutrophils recruited to the intestinal epithelium did not show evidence of degranulation and the epithelium remained intact as judged by histology. CONCLUSIONS: This conditional transgenic model of chemokine expression provides evidence that acute induction of IL-8 in the intestinal epithelium is sufficient to trigger neutrophil recruitment to the lamina propria, but additional activation signals are needed for full activation and degranulation of neutrophils, mucosal injury, and complete transepithelial migration.

Preparation of poly(epsilon-caprolactone)/continuous bioglass fibre composite using monomer transfer moulding for bone implant.

Poly(epsilon-caprolactone) (PCL)/continuous bioglass fibre composite was prepared using the monomer transfer moulding technique coupled with a surface initiated polymerisation. The bioglass fibres were surface treated with an amine ended silane in order to initiate polymerisation of epsilon-caprolactone from the fibre surface. Surface initiated polymerisation significantly improved the Young's modulus and flexural strength and water resistance of the composite. Initial in vitro biocompatibility assessment suggests that amine ended silane treatment of bioglass fibres before their inclusion in the composite does not have a negative effect on the biological responses in terms of macrophage activation as measured by IL-1beta release and craniofacial osteoblast attachment.

Alanylglutamine dipeptide and growth hormone maintain PepT1-mediated transport in oxidatively stressed Caco-2 cells.

Reactive oxygen species (ROS) produced by gut mucosal cells during conditions such as inflammatory bowel disease (IBD) may impair mucosal repair and nutrient transport/absorptive function. Absorption of di- and tripeptides in the small intestine and colon is mediated by the H(+)-dependent transporter PepT1, but effects of oxidative stress on di- and tripeptide transport are unknown. We assessed whether exposure to hydrogen peroxide (H(2)O(2)) influences dipeptide transport in human colonic epithelial (Caco-2) cells. Uptake of [(14)C]glycylsarcosine (Gly-Sar) was used to evaluate PepT1-mediated dipeptide transport. Exposure to 1-5 mmol/L H(2)O(2) for 24 h caused a dose-dependent decrease in Gly-Sar transport, which was associated with decreased PepT1 transport velocity (V(max)). Treatment with alanylglutamine (Ala-Gln) or growth hormone (GH) did not alter Caco-2 Gly-Sar transport in the absence of H(2)O(2). However, both Ala-Gln and GH prevented the decrease in dipeptide transport observed with 1 mmol/L H(2)O(2) treatment. Ala-Gln, but not GH, maintained cellular glutathione and prevented the decrease in PepT1 protein expression. Thus, these agents should be further investigated as potential therapies to improve absorption of small peptides in disorders associated with oxidative injury to the gut mucosa.

Selection of oxacillin resistance in oxacillin-sensitive Staphylococcus aureus through exposure to ciprofloxacin but not piperacillin/tazobactam.

Ten oxacillin-sensitive Staphylococcus aureus strains were grown on agar containing four times their ciprofloxacin MIC to determine if exposure to ciprofloxacin would increase their resistance to oxacillin. All strains grew on the ciprofloxacin-containing agar and subsequently grew on oxacillin-salt agar. The geometric mean MICs for oxacillin increased one- to sixteen-fold and remained elevated after ten passages on antibiotic-free agar. The mecA gene was not detected in any strain. There was no increase in oxacillin MICs when the bacteria were passaged on agar containing four times their MIC of piperacillin/tazobactam. Exposure of oxacillin-sensitive strains of Staphylococcus aureus to ciprofloxacin may increase their MICs to oxacillin.

Conflict in healthcare organizations.

Healthcare organizations struggle with internal and external causes of conflict. Successful organizations evaluate and retool existing conflict management systems to constructively, cost-effectively and practically control the negative impact.

Outcomes associated with clinical profiles of children in psychiatric crisis enrolled in intensive, in-home interventions.

Little is known about the characteristics of children and youth presenting at emergency settings in psychiatric crisis, and virtually nothing is known about their outcomes. The purpose of this study is to describe the clinical profiles of 238 children presenting at two psychiatric emergency settings and enrolled in a randomized controlled trial of three intensive in-home interventions. A second purpose is to examine child mental health outcomes, based on clinical profile and to suggest the utility of using a clinical-profiles approach.

Levofloxacin failure in a patient with pneumococcal pneumonia.

OBJECTIVE: To report a case of levofloxacin failure in a patient with a penicillin-sensitive Streptococcus pneumoniae pneumonia. CASE SUMMARY: A previously healthy, immunocompetent, 53-year-old white man presented with penicillin-sensitive S. pneumoniae pneumonia. The patient was empirically placed on levofloxacin monotherapy, which was continued due to a local penicillin shortage. When the patient failed to improve, further susceptibility testing was ordered. The organism was found to have a penicillin minimum inhibitory concentration (MIC) of 0.023 microgram/mL and a levofloxacin MIC of 6 micrograms/mL. Effective antimicrobial therapy was delayed, as clinicians did not anticipate fluoroquinolone resistance. DISCUSSION: Newer fluoroquinolones such as levofloxacin have good activity against most S. pneumoniae isolates and are used for the treatment of pneumonia. Although resistance to these agents is rare, it has been reported. Current guidelines from the National Committee for Clinical Laboratory Standards do not recommend initial fluoroquinolone susceptibility testing. CONCLUSIONS: As fluoroquinolone resistance may not be identified by susceptibility patterns to other antibiotics, early fluoroquinolone susceptibility testing and increased awareness of resistance may aid clinicians in their treatment of pneumococcal disease.

Conducting research in culturally diverse inner-city neighborhoods: some lessons learned.

Social, behavioral, and health research among disenfranchised groups in inner cities poses problems in collecting data. It is a challenge to achieve data of sufficient quantity and quality necessary to be scientifically usable. This article describes the experiences of a research team during two phases of data collection in a mental health intervention study in New York's South Bronx. Challenges in addressing human subject concerns, the formation of a fieldwork team, enrollment and retention of respondents, and administration of instruments are described and solutions are discussed. Emphasis is placed on researchers' approaches to the selection, orientation, and safety of interviewers, interviewer-respondent race and ethnic matching, contacts and rapport with respondents, and the handling of such interpersonal issues as distrust, poor cooperation, and family dynamics. The procedures developed took into consideration the culture and life conditions of the population to ensure a satisfactory response rate and high-quality data.

Determining the frequency of resistance of Streptococcus pneumoniae to ciprofloxacin, levofloxacin, trovafloxacin, grepafloxacin, and gemifloxacin.

Newer fluoroquinolones have good activity against Streptococcus pneunoniae and may be useful clinically for the treatment of pneumonia. Although resistance among Streptococcus pneumoniae has been reported, it is rare. The frequency of single-step resistance and the emergence of resistance were compared in serial transfer of 49 clinical isolates of penicillin-sensitive and -resistant Streptococcus pneumoniae to ciprofloxacin, levofloxacin, trovafloxacin, grepafloxacin, and gemifloxacin. Single-step resistance frequencies to four times the minimum inhibitory concentration were 2.73 x 10(-6) (+/- 8.46 x 10(-6)) for ciprofloxacin, 1.78 x 10(-7) (+/- 4.62 x 10(-7)) for trovafloxacin, 5.45 x 10(-7) (+/- 1.24 x 10(-6)) for grepafloxacin, 6.78 x 10(-7) (+/- 1.38 x 10(-6)) for gemifloxacin, and 9.23 x 10(-8) (+/- 4.47 x 10(-7)) for levofloxacin. In serial transfer experiments, all isolates became resistant to clinically relevant levels of all fluoroquinolones after eight passages. The resistance occurred most rapidly with ciprofloxacin followed by grepafloxacin, gemifloxacin, trovafloxacin, and levofloxacin. These results show that strains with decreased susceptibility to fluoroquinolones occur frequently in cultures of Streptococcus pneumoniae, and this organism can readily become resistant to clinically relevant concentrations of fluoroquinolones in vitro.

Clinical infection control in gene therapy: a multidisciplinary conference.

Gene therapy is being studied for the treatment of a variety of acquired and inherited disorders. Retroviruses, adenoviruses, poxviruses, adeno-associated viruses, herpesviruses, and others are being engineered to transfer genes into humans. Treatment protocols using recombinant viruses are being introduced into clinical settings. Infection control professionals will be involved in reviewing the safety of these agents in their clinics and hospitals. To date, only a limited number of articles have been written on infection control in gene therapy, and no widely available recommendations exist from federal or private organizations to guide infection control professionals. The goals of the conference were to provide a forum where gene therapy experts could share their perspectives and experience with infection control in gene therapy and to provide an opportunity for newcomers to the field to learn about issues specific to infection control in gene therapy. Recommendations for infection control in gene therapy were proposed.

Genetic diversity and reproductive biology in Warea carteri (Brassicaceae), a narrowly endemic Florida scrub annual.

Carter's mustard (Warea carteri) is an endangered, fire-stimulated annual endemic of the Lake Wales Ridge, Florida, USA. This species is characterized by seed banks and large fluctuations in plant numbers, with increases occurring in postdisturbance habitat. We investigated the mating system, patterns of isozyme variation, and effective population sizes of W. carteri to better understand its population biology and to comment on reserve designs and management proposals relevant to this species. Warea carteri is self-compatible and autogamous, and probably largely selfing. Measures of genetic variation in W. carteri were lower than values reported for species with similar ecological and life history traits (6.6% of loci polymorphic within populations, 1.87 alleles per polymorphic locus, and 0.026 and 0.018 expected and observed heterozygosity, respectively). The high average value for Nei's genetic identity (0.989) reflects the paucity of genetic diversity. Genetic variation within populations was not correlated with aboveground population size, effective population size estimates (N(e)), or recent disturbance history. Much of the diversity detected was found among populations (F(ST) = 0.304). A significant cline in allele frequencies at one locus and a significant negative correlation between geographic distance and Nei's genetic identity also point to spatial organization of genetic diversity. As a result we propose that reserve design should include the entire geographic range of W. carteri. We also recommend that the natural fire regime be mimicked.

An evaluation of statewide strategies to reduce antibiotic overuse.

BACKGROUND: The rapid increase of antibiotic resistance poses a significant threat to human health. Overuse of antibiotics has been linked to rates of antibiotic resistance. This study assessed the utility of two common interventions--1) practice profiling and feedback and 2) patient education materials--implemented to decrease antibiotic prescribing for pediatric upper respiratory infections (URIs). METHODS: Based on Medicaid regions in Kentucky, primary care physicians managing pediatric respiratory infections in Medicaid were randomized into four groups. Groups received either 1) performance feedback only, 2) patient education materials only, 3) both feedback and education materials, or 4) no intervention. Participating physicians had their antibiotic prescribing assessed for the period of July 1, 1996, to November 30, 1997, with an intervention in June 1997. The study included 216 physicians and 124,092 episodes of care. RESULTS: All groups increased in proportion of episodes with antibiotics between the pre-intervention and post-intervention periods. Prescribing in the patient education group and the patient education and feedback group increased at a significantly lower rate than in the control group. Physicians did not change their coding of illness to justify antibiotics after the intervention, and there was no significant generalization of effect of the pediatric intervention on prescribing for adult URIs. CONCLUSIONS: These interventions demonstrate little if any impact on promoting appropriate antibiotic prescribing. Antibiotic prescribing for viral respiratory infections continues to increase, suggesting concomitant increases in antibiotic resistance.

Polymyxin B sulfate and colistin: old antibiotics for emerging multiresistant gram-negative bacteria.

BACKGROUND: Polymyxin B sulfate and colistin, also known as colistimethate, have not been used for many years because less toxic antimicrobials are available. Gram-negative bacteria that are resistant to the aminoglycosides, beta-lactams, and fluoroquinolones are becoming more common. These bacteria are often susceptible to the polymyxins. OBJECTIVE: To present a review of the chemistry, antibacterial spectrum, dosing, pharmacokinetics, toxicity, and indications for polymyxin B sulfate and colistin. DATA SOURCE: A MEDLINE search (1966-1998) of the English-language literature was performed to identify primary literature on the polymyxins. Older citations ( 1949-1965) were identified through the bibliographies of these articles. STUDY SELECTION: All available reports of in vitro antibacterial activity, animal and clinical trials, and case reports were reviewed. DATA SYNTHESIS: The polymyxins are amphipathic molecules that interact with lipopolysaccharide in the bacterial outer membrane. They have potent antiendotoxic properties and antibacterial activity against Pseudomonas aeruginosa and many of the Enterobacteriaceae. Polymyxin B and colistin are usually given at a dose of 1.5-2.5 and 5 mg/kg/d, respectively, in two divided doses. Dosing must be altered in renal failure since the kidney is the primary route of elimination. Distribution into pleural fluid, joints, and cerebrospinal fluid is poor. Toxic effects involve the kidney and central nervous system. The polymyxins are recommended for serious systemic infections caused by gram-negative bacteria that are resistant to other agents. CONCLUSIONS: Polymyxin B sulfate and colistin have a role in the therapy of multidrug-resistant gram-negative bacterial infections.

Infection control in gene therapy.

Gene therapy is now being studied for the treatment of a wide variety of acquired and inherited diseases. Viruses used as vectors for gene transfer include retroviruses, adenoviruses, vaccinia viruses, adeno-associated viruses, and herpesviruses. These vectors, developed in the laboratory and in animal studies, are now being introduced into the clinical arena Infection control practitioners will be involved invariably in reviewing the use of these agents in their clinics and hospitals. This review summarizes key aspects of the more common vectors and makes recommendations for infection control.