Peripheral cytokine responses to Trichuris muris reflect those occurring locally at the site of infection

The study of human cellular immune responses to parasite infection under field conditions is very complex. Often, the only practical site from which to sample the cellular responses is the peripheral blood. Sampling peripheral blood lymphocytes (PBL) relies on the assumption that these peripheral responses accurately reflect the immune responses acting locally at the site of infection. This is a particularly important point for the human intestinal helminth Trichuris trichiura, which solely inhabits the cecum and large intestine and so will stimulate a localized immune response. Using the well-defined model of T. trichiura, T. muris in the mouse, we have demonstrated that the dominant cytokine responses of the mesenteric lymph nodes (MLN) can be detected by sampling PBL. Resistant mice which mount a type 2 cytokine response in their MLN had PBL producing interleukin-4 (IL-4), IL-5, and IL-9, with negligible levels of gamma interferon (IFN-gamma). Conversely, susceptible mice which mount a type 1 cytokine response in their MLN had PBL producing IFN-gamma and negligible levels of type 2 cytokines. We have also shown that the PBL are capable of mounting a functional immune response against T. muris. PBL from immune mice were capable of transferring immunity to T. muris-infected severe combined immunodeficient (C.B-17 scid/scid) mice. Sampling PBL responses is therefore a viable option for monitoring human intestinal immune responses during T. trichiura infection in the field.     

Comparison of Nine Commercially Available Clostridium difficile Toxin Detection Assays,a Real-Time PCR Assay for C. difficile tcdB,and a Glutamate Dehydrogenase Detection Assay to Cytotoxin Testing and Cytotoxigenic Culture Methods

The continuing rise in the incidence of Clostridium difficile infection is a cause for concern, with implications for patients and health care systems. Laboratory diagnosis largely relies on rapid toxin detection kits, although assays detecting alternative targets, including glutamate dehydrogenase (GDH) and toxin genes, are now available. Six hundred routine diagnostic diarrheal samples were tested prospectively using nine commercial toxin detection assays, cytotoxin assay (CYT), and cytotoxigenic culture (CYTGC) and retrospectively using a GDH detection assay and PCR for the toxin B gene. The mean sensitivity and specificity for toxin detection assays were 82.8% (range, 66.7 to 91.7%) and 95.4% (range, 90.9 to 98.8%), respectively, in comparison with CYT and 75.0% (range, 60.0 to 86.4%) and 96.1% (91.4 to 99.4%), respectively, in comparison with CYTGC. The sensitivity and specificity of the GDH assay were 90.1% and 92.9%, respectively, compared to CYT and 87.6% and 94.3%, respectively, compared to CYTGC. The PCR assay had the highest sensitivity of all the tests in comparison with CYT (92.2%) and CYTGC (88.5%), and the specificities of the PCR assay were 94.0% and 95.4% compared to CYT and CYTGC, respectively. All kits had low positive predictive values (range, 48.6 to 86.8%) compared with CYT, assuming a positive sample prevalence of 10% (representing the hospital setting), which compromises the clinical utility of single tests for the laboratory diagnosis of C. difficile infection. The optimum rapid single test was PCR for toxin B gene, as this had the highest negative predictive value. Diagnostic algorithms that optimize test combinations for the laboratory diagnosis of C. difficile infection need to be defined.Clostridium difficile is a major nosocomial pathogen causing a range of symptoms from mild to severe diarrhea and is the etiological agent of pseudomembranous colitis. The incidence of C. difficile infection has increased markedly in many countries, notably associated with the epidemic spread of PCR ribotype 027 (NAP1) since its recognition in the United States and Canada (6, 7, 13). It is essential to have accurate laboratory diagnosis of C. difficile infection to ensure patients receive appropriate treatment and that correct infection control measures are put in place. Also, inaccurate testing will potentially lead to poor quality surveillance data that may lead to inappropriate infection prevention measures.The cytotoxin assay (CYT), first described by Chang et al., detects the toxins produced by C. difficile in the supernatants of patient feces, using both antitoxin-protected and nonprotected cell monolayers (2). This assay is commonly used as the gold standard method for comparison in toxin kit evaluations, although its use in routine microbiology laboratories has largely been superseded. Cytotoxogenic culture (CYTGC) has been used as an alternative gold standard method to CYT testing, i.e., where CYT testing is performed using culture supernatants instead of directly from the fecal sample (1). These are lengthy assays, however, with results delayed for 24 to 48 h for the CYT and for more than 72 h for the CYTGC assay.Rapid, commercially available, toxin detection kits removed the need for laboratories to maintain the cell lines necessary for CYT testing. Although originally designed to detect either toxin A or toxin B, the kits currently available detect both toxins to enable detection of toxin A-negative, toxin B-positive strains. Alternative detection methods have now been developed, including an assay that detects a surface-associated enzyme of C. difficile, glutamate dehydrogenase (GDH). Zheng et al. reported that the Techlab C. diff Chek-60 GDH assay had good sensitivity compared to CYT testing of 92%, but it had a low specificity of 89.1% and poor positive predictive value (PPV) of 57.7% (21). Commercial molecular diagnostic tests, such as the BD GeneOhm C. difficile PCR assay, which detects the tcdB toxin gene of C. difficile, are now available. A recent study compared this assay to CYT testing and found a sensitivity and specificity of 90.9% and 95.2%, respectively (15). The PPVs of the BD GeneOhm C. difficile PCR assay were only 70.2% compared with CYT testing and 89.5% compared with CYTGC (15), with a prevalence of toxin-positive fecal samples of 15.2%.Despite numerous evaluations of C. difficile testing methods, no evaluation has compared all methods on the same sample set. This study compared six commercially available enzyme immunoassays (EIAs) and three lateral-flow assays for detection of C. difficile toxins A and B, a PCR assay for detection of the tcdB gene of C. difficile, and an assay for detection of C. difficile-specific GDH, with CYT testing and CYTGC.     

Hydrocelectomy under local anaesthesia in a Nigerian adult population

Background

Hydrocele is abnormal collection of serous fluid in the tunica vaginalis or a patent processus vaginalis. It is commonly encountered in our practice and often requires surgical treatment. However in our setting and in many underdeveloped countries, availability of general anaesthetic service is poor due to lack of trained personnel and equipment.

Objectives

To ascertain the practicability and acceptability of hydrocelectomy under sedation and local anaesthesia in Nigerian adults with hydrocele

Patients and Methods

A prospective study was carried out over a two year period on patients that had hydrocelectomy at the surgery unit of the Obafemi Awolowo University Teaching Hospitals Complex, Wesley Guild Hospital, Ilesa. Consecutive patients with diagnosis of hydrocele who consented had hydrocelectomy using intramuscular diazepam sedation and spermatic-cord block with 0.5% plane xylocaine and the scrotum infiltrated with same along the line of incision.

Results

Fifty adult patients were studied: age range 15–94 years. Eighty percent of the patients had unilateral hydrocele and the commonest type was vaginal hydrocele (94%). All patients had hydrocelectomy, 96% were under local anaesthesia while 4% were converted to general anaesthesia. All patients except one prefer to have future surgery under such local anaesthesia and sedation.

Conclusion

Hydrocelectomy under local anaesthesia and sedation is practicable and was tolerated and accepted by the adults patients studied.     

The relevance of team characteristics and team directed strategies in the implementation of nursing innovations: A literature review

BackgroundImplementation of innovations is a complex and intensive procedure in which different strategies can be successful. In nursing, strategies often focus on intrinsic motivation, competencies and attitudes of individual nurses while ignoring the social context. Since nurses often work in teams, identifying relevant team characteristics and successful team directed strategies may contribute to the implementation of innovations. The literature was searched for evidence.MethodsA literature review was performed including key words related to nursing teams, innovations, team characteristics and team-directed strategies. On-line databases were searched (MEDLINE, CINAHL, PsycINFO, ERIC database and Cochrane reviews CENTRAL). The journal Quality and Safety in Healthcare (QSHC) was hand searched. Methodological quality was assessed.ResultsInitially, 323 titles were found. Screening of titles and abstracts and full texts resulted in nine articles meeting the inclusion criteria. The methodological quality of the studies was generally low. The innovations included different types of practices. Fifteen different team characteristics were labeled according to six features of successful teams.Twenty-one different team-directed strategies were identified and inductively categorized.ConclusionFew studies and little evidence were found for the relevance of team characteristics and team directed strategies in the implementation of nursing innovations. Feedback was most frequently used as a strategy. Leadership could be labeled as a team characteristic as well as a team directed strategy. Further research should be of good methodological quality and focusing on patient outcomes and time and costs invested in strategy delivery. This increases scientific knowledge on nursing implementation strategies focusing on leadership.     

A multiplatform real-time polymerase chain reaction detection assay for Vibrio cholerae

We report a multiplatform real-time polymerase chain reaction methodology based on genes encoding for the regulatory toxR activator and enterotoxin A protein to determine enterotoxigenic Vibrio cholerae types from other vibrios. This assay, which was successfully validated on a collection of 87 bacterial strains, including 63 representatives of V. cholerae and 8 noncholera vibrios provides a rapid tool for detection and identification of cholera.     

Deletions of CDKN2C in multiple myeloma: biological and clinical implications

PURPOSE: Deletions of chromosome 1 have been described in 7% to 40% of cases of myeloma with inconsistent clinical consequences. CDKN2C at 1p32.3 has been identified in myeloma cell lines as the potential target of the deletion. We tested the clinical impact of 1p deletion and used high-resolution techniques to define the role of CDKN2C in primary patient material. EXPERIMENTAL DESIGN: We analyzed 515 cases of monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and newly diagnosed multiple myeloma using fluorescence in situ hybridization (FISH) for deletions of CDKN2C. In 78 myeloma cases, we carried out Affymetrix single nucleotide polymorphism mapping and U133 Plus 2.0 expression arrays. In addition, we did mutation, methylation, and Western blotting analysis. RESULTS: By FISH we identified deletion of 1p32.3 (CDKN2C) in 3 of 66 MGUS (4.5%), 4 of 39 SMM (10.3%), and 55 of 369 multiple myeloma cases (15%). We examined the impact of copy number change at CDKN2C on overall survival (OS), and found that the cases with either hemizygous or homozygous deletion of CDKN2C had a worse OS compared with cases that were intact at this region (22 months versus 38 months; P = 0.003). Using gene mapping we identified three homozygous deletions at 1p32.3, containing CDKN2C, all of which lacked expression of CDKN2C. Cases with homozygous deletions of CDKN2C were the most proliferative myelomas, defined by an expression-based proliferation index, consistent with its biological function as a cyclin-dependent kinase inhibitor. CONCLUSIONS: Our results suggest that deletions of CDKN2C are important in the progression and clinical outcome of myeloma.     

K+ currents activated by leukotriene D4 or osmotic swelling in Ehrlich ascites tumour cells

K+ and Cl- currents activated by hypoosmotic cell swelling (IK,vol and Icl,vol) or after addition of leukotriene D4 (LTD4) to cells in isotonic medium were studied in Ehrlich ascites tumour cells. IK,vol and Icl,vol were not affected by strong buffering of intracellular Ca2+ or by additional removal of extracellular Ca2+. In isotonic media, 5 nmol/l LTD4 activated large K+ but not Cl- currents. The LTD4-activated IK was, as has been shown previously for IK,vol, insensitive to charybdotoxin (ChTX) but was blocked by the antiarrhythmic drug clofilium. The current/voltage (I/V) relation for the LTD4-activated IK was, as recently demonstrated for IK,vol, well fitted by the Goldman-Hodgkin-Katz current equation between -130 mV and 30 mV in both physiological and K+-rich extracellular solutions. LTD4 had no additional effect on the magnitude of IK in Ehrlich cells already activated by the hypoosmotic stimulus. Nevertheless, the onset time for IK after hypoosmotic cell swelling was significantly less in the presence of LTD4. The similar I/V relation, pharmacological sensitivity and lack of additivity suggest that hypoosmotic swelling and addition of LTD4 activate the same K+ channels in Ehrlich cells. The influence of [Ca2+]i appears, however, to differ between IK,vol and the IK activated by LTD4 in that the latter was reduced significantly by strong buffering of [Ca2+]i. This might reflect the involvement of some additional factor in the hypoosmotic activation of K+ channels besides the stimulation mediated by LTD4.     

An observational study of slimming behavior in Denmark in 1992 and 1998

OBJECTIVE: To elucidate how frequent weight-loss attempts are made, the methods used to achieve weight loss, and the extent to which the outcome is positive. RESEARCH METHODS AND PROCEDURES: Two independent interviews were conducted in 1992 and in 1998, each with 1200 randomly selected adult subjects. Each survey was designed to ensure an equal distribution of age, gender, and geographical regions in Denmark. RESULTS: The proportion of subjects having attempted weight loss did not change from 1992 to 1998, although the prevalence of overweight and obesity increased from 1992 (overweight, 30%; obesity, 6%) to 1998 (overweight, 35%; obesity, 8%). Almost twice as many women (61%) than men (32%) had attempted weight loss (p < 0.0001). Slimming occurred more often in subjects <50 years (51%) than >50 years (39%) (p < 0.0001), although overweight and obesity were more frequent in the elderly. Over-the-counter diet pills or meal replacements were associated with a negative outcome of slimming treatment (p < 0.0001). DISCUSSION: Approximately half of all adult Danes have attempted weight loss, particularly women and individuals <50 years. This finding is inconsistent with the fact that overweight and obesity are more prevalent in men and in individuals >50 years. Changes in habitual diet and increased physical activity are the most prevalent modes of slimming, whereas the use of over-the-counter diet pills or meal replacements has decreased from 1992 to 1998. This development may have a positive impact on future body- weight-management strategies.