The mediation role of work-life balance stress and chronic fatigue in the relationship between workaholism and depression among Chinese male workers in Hong Kong.

BACKGROUND AND AIMS: Few studies have tested the underlying mechanisms in the association between workaholism and depression. This study aims to investigate the potential mediation effects of work-life balance stress and chronic fatigue and depression among Chinese male workers in Hong Kong. METHODS: A population-based study among male workers in Hong Kong (n = 1,352) was conducted. The self-reported scales of assessing workaholism, work-life balance stress, chronic fatigue and depressive symptoms were included in the questionnaire. Path analysis was conducted to test the proposed mediation model. RESULTS: Workaholism was directly and indirectly associated with depression through work-life balance stress and chronic fatigue, respectively. The association between work-life balance stress and chronic fatigue was statistically significant in the correlation analysis but not in the path analysis. As high as 30.5% of the participants were classified as having probable chronic fatigue, while 8.4% of the participants were classified as having probable depression. DISCUSSION: Workaholism is a stressor that may induce negative consequences on well-being and health among male workers in Hong Kong. Interventions to help workers with time and stress management and fatigue reduction may be beneficial for their mental health. Theoretical and practical implications are discussed.

Prevalence of binge drinking and relationships between masculine role discrepancy and binge drinking via discrepancy stress among Chinese men.

BACKGROUND: Binge drinking is prevalent among male populations. Few studies have investigated masculine role discrepancy (i.e., the perception of being less masculine than the typical 'man')/discrepancy stress (i.e., the strain caused by perceived masculine role discrepancy) and binge drinking among men. This study aims to investigate the prevalence of binge drinking among Chinese men and the associations between masculine role discrepancy and binge drinking via discrepancy stress. METHODS: A random and population-based telephone survey was conducted among Chinese male adults (n = 2000) in Hong Kong. Their levels of masculine role discrepancy and discrepancy stress and presence of binge drinking were tested. RESULTS: We found that 12.3% of the participants had binge drinking behaviors during the last three months prior to the survey. Age and marital status were significantly associated with binge drinking behaviors. Discrepancy stress was positively associated with binge drinking, and it positively mediated the relationship between masculine role discrepancy and binge drinking. However, we found a negative direct association between masculine role discrepancy and binge drinking in the mediation model. CONCLUSION: The study may shed light on a relatively new and important research direction that links up gender roles and substance use problems. It contributes to an understanding of the potential health impact of gender-role related issues as well as determinants of drinking problems.

Potential roles of masculine role discrepancy, discrepancy stress, and self-esteem in affecting addictive use of social networking sites among Chinese men: A random population-based study.

BACKGROUND AND AIMS: Masculine role discrepancy (i.e., men perceiving themselves not living up to the ideal manhood and being less masculine than the typical "man") and related discrepancy stress were associated with some risk behaviors. No study has looked at their relationships with addictive use of social networking sites (SNSs), an emerging potential public health concern. The study constructed a moderated mediation model to test whether masculine role discrepancy would be positively associated with discrepancy stress, which would, in turn, be positively associated with addictive use of SNS, and whether self-esteem would buffer (moderate) the association between masculine role discrepancy and discrepancy stress. METHODS: A random population-based cross-sectional telephone survey interviewed 2,000 Hong Kong male adults in the general population. RESULTS: Currently unmarried and non-cohabiting, younger, and better educated participants reported higher addictive use of SNS scores than others. Adjusted for these variables, masculine role discrepancy and discrepancy stress were positively associated, and self-esteem was negatively associated with addictive use of SNS scores. Path analysis indicated that masculine role discrepancy was associated with addictive use of SNS through discrepancy stress (mediation); self-esteem buffered (moderated) the association between masculine role discrepancy and discrepancy stress; self-esteem was not significantly associated with addictive use of SNS in this model with good fit. DISCUSSION: The findings support the general strain theory's postulation that strain is associated with stress, which is in turn associated with addictive use of SNS sites. Implications, potential interventions, and future studies are discussed in this study.

Bidirectional predictions between Internet addiction and probable depression among Chinese adolescents.

BACKGROUND AND AIMS: The aim of the study is to investigate (a) whether probable depression status assessed at baseline prospectively predicted new incidence of Internet addiction (IA) at the 12-month follow-up and (b) whether IA status assessed at baseline prospectively predicted new incidence of probable depression at follow-up. METHODS: We conducted a 12-month cohort study (n = 8,286) among Hong Kong secondary students, and derived two subsamples. The first subsample (n = 6,954) included students who were non-IA at baseline, using the Chen Internet Addiction Scale (≤63), and another included non-depressed cases at baseline (n = 3,589), using the Center for Epidemiological Studies Depression Scale (<16). RESULTS: In the first subsample, 11.5% of the non-IA cases developed IA during follow-up, and probable depression status at baseline significantly predicted new incidence of IA [severe depression: adjusted odds ratio (ORa) = 2.50, 95% CI = 2.07, 3.01; moderate: ORa = 1.82, 95% CI = 1.45, 2.28; mild: ORa = 1.65, 95% CI = 1.32, 2.05; reference: non-depressed], after adjusting for sociodemographic factors. In the second subsample, 38.9% of those non-depressed participants developed probable depression during follow-up. Adjusted analysis showed that baseline IA status also significantly predicted new incidence of probable depression (ORa = 1.57, 95% CI = 1.18, 2.09). DISCUSSION AND CONCLUSIONS: The high incidence of probable depression is a concern that warrants interventions, as depression has lasting harmful effects in adolescents. Baseline probable depression predicted IA at follow-up and vice versa, among those who were free from IA/probable depression at baseline. Healthcare workers, teachers, and parents need to be made aware of this bidirectional finding. Interventions, both IA and depression prevention, should thus take both problems into consideration.

The mediation roles of discrepancy stress and self-esteem between masculine role discrepancy and mental health problems.

INTRODUCTION: Masculine role discrepancy and discrepancy stress occur when men perceive that they fail to live up to the ideal manhood derived from societal prescriptions. The present study examined the associations between masculine role discrepancy and two emotional and mental health problems (social anxiety and depressive symptoms), and potential mediation effects through discrepancy stress and self-esteem in a male general population. METHODS: Based on random population-based sampling, 2000 male residents in Hong Kong were interviewed. Levels of masculine role discrepancy, discrepancy stress, self-esteem, social anxiety, and depressive symptoms were assessed by using validated scales. RESULTS: Results of structural equation modeling analysis indicated that the proposed model fit the sample well. (χ2(118) = 832.34, p < .05, CFI = 0.94, NNFI = 0.91, RMSEA = 0.06). Those who were young, single and less educated were vulnerable to masculine role discrepancy, discrepancy stress, and emotional/mental health problems. We found that discrepancy stress significantly mediated the association between masculine role discrepancy and social anxiety, while self-esteem significantly mediated the associations between masculine role discrepancy and both social anxiety and depression. LIMITATIONS: Study limitations mainly included the cross-sectional design and reliance on self-reported questionnaires. CONCLUSIONS: The associations between masculine discrepancy and social anxiety/depressive symptoms among men may be explained by the increase in discrepancy stress and decrease in self-esteem. The findings suggest needs and directions for future research for the relationship between masculine role discrepancy and men's mental health, mechanisms involved, and interventions for improvement.

Predictors of remission from probable depression among Hong Kong adolescents - A large-scale longitudinal study.

BACKGROUND: This study investigated the incidence of remission from probable depression among adolescents in Hong Kong. Remissions were defined as having Center for Epidemiological Studies Depression Scale (CESD) scores changed from ≥16 at baseline to <16 over the 12-month follow-up period. The study tested the predictors of remissions, including perceived changes in family support, self-efficacy, self-esteem, positive affect, negative events, social anxiety, and loneliness. METHODS: The study surveyed 9666 secondary school students and identified 5487 (57%) students with probable depression in Hong Kong. A questionnaire assessing the levels of the aforementioned variables was completed at baseline and at the 12-month follow-up. RESULTS: Among participants with probable depression at baseline, 23.2% remitted from depression at follow-up. Remissions were more common among males than females. Univariate logistic regression showed that perceived changes in all the aforementioned variables significantly predicted remission for both males and females. The same is true for most of these variables when they were entered together into multiple logistic regression models (with and without controlling for baseline CESD scores), except for family support in the female model and self-efficacy in both male and female models. LIMITATIONS: Limitations include potential self-report bias and only one follow-up observation over time. The design treats cases of probable mild to severe depression as a single group (CESD≥16). CONCLUSIONS: The findings are potentially useful for designing and guiding related intervention programs. Results highlight the importance of long-term follow-up of those screened as probable depression to understand the course of changes in levels of depression.

CD4+ CD25+ transforming growth factor-beta-producing T cells are present in the lung in murine tuberculosis and may regulate the host inflammatory response.

CD4(+) CD25(+) regulatory T cells produce the anti-inflammatory cytokines transforming growth factor (TGF)-beta or interleukin (IL)-10. Regulatory T cells have been recognized to suppress autoimmunity and promote self-tolerance. These cells may also facilitate pathogen persistence by down-regulating the host defence response during infection with Mycobacterium tuberculosis. We evaluated TGF-beta(+) and IL-10(+) lung CD4(+) CD25(+) T cells in a murine model of M. tuberculosis. BALB/c mice were infected with approximately 50 colony-forming units of M. tuberculosis H37Rv intratracheally. At serial times post-infection, lung cells were analysed for surface marker expression (CD3, CD4, CD25) and intracellular IL-10, TGF-beta, and interferon (IFN)-gamma production (following stimulation in vitro with anti-CD3 and anti-CD28 antibodies). CD4(+) lung lymphocytes were also selected positively after lung digestion, and stimulated in vitro for 48 h with anti-CD3 and anti-CD28 antibodies in the absence and presence of anti-TGF-beta antibody, anti-IL-10 antibody or rmTGF-beta soluble receptor II/human Fc chimera (TGFbetasrII). Supernatants were assayed for elicited IFN-gamma and IL-2. Fluorescence activated cell sorter analyses showed that TGF-beta- and IL-10-producing CD4(+) CD25(+) T cells are present in the lungs of infected mice. Neutralization of TGF-beta and IL-10 each resulted in increases in elicited IFN-gamma, with the greatest effect seen when TGFbetasrII was used. Elicited IL-2 was not affected significantly by TGF-beta neutralization. These results confirm the presence of CD4(+) CD25(+) TGF-beta(+) T cells in murine pulmonary tuberculosis, and support the possibility that TGF-beta may contribute to down-regulation of the host response.

The effects of alcohol on immunity and bacterial infection in the lung.

When faced with invading pathogens that can lead to infection, patients must mount an effective and appropriate immune response. Altered immune function in patients who abuse alcohol has long been described in the medical literature. The alcohol-consuming host is particularly prone to infections in the lung, including bacterial pneumonia and tuberculosis. Over the last several decades, there has been increased interest in the immune mechanisms that underlie the increased risk of infection observed in this population. This article will review the basic immunology involved in the host response to an infection and then describe how alcohol disrupts many of these immune mechanisms. It will further provide an overview of lung infections which have been linked to alcohol abuse, and finally, it will address the evolving therapeutic approaches of the immune system that are being advanced to assist in caring for immunosuppressed hosts.

Chemokine receptor 5 and its ligands in the immune response to murine tuberculosis.

SETTING: The ability of chemokines such as macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, and regulated-upon-activation, normal T cell expressed and secreted (RANTES), to attract and activate T cells and monocytes, the building blocks of the granuloma, suggests that these chemokines may have a role in modulating immune responses to Mycobacterium tuberculosis infection. OBJECTIVE: We hypothesized that the chemokine receptor 5 (CCR5) ligands, MIP-1alpha, MIP-1beta and RANTES, are virulence correlates in M. tuberculosis infection and are indispensable to granuloma formation. DESIGN: The ability of virulent (H37Rv) and avirulent (H37Ra) strains of M. tuberculosis to induce chemokine production in vivo and in vitro was determined at protein and mRNA levels. We also compared bacterial burden, and granuloma numbers and size in H37Rv-infected CCR5-/- or wild-type C57BL/6 mice. RESULTS: In vivo, lung mRNA and protein measurements of MIP-1alpha, MIP-1beta and RANTES indicate significantly higher (p<0.05) values (days 14-28) in the H37Rv-infected than the H37Ra-infected mice. This is consistent with a higher infection burden of the virulent strain. However, in vitro alveolar macrophage stimulation by H37Rv or H37Ra yielded no significant differences in production of the three chemokines at all time points. Histological analysis of granulomas did not show any significant differences in granuloma numbers, size and M. tuberculosis growth in CCR5-/- compared to wild-type mice. CONCLUSIONS: The production of the CCR5 ligands, MIP-1alpha, MIP-1beta, and RANTES, does not clearly correlate with virulence of M. tuberculosis. These ligands and their receptors may not be indispensable to the development of granulomas in murine tuberculosis.

Streptococcus grouping latex kits: evaluation of five commercially available examples.

This study compares a recently introduced latex agglutination test for the serogrouping of beta-haemolytic streptococci against four internationally used commercial kits. The new kit is Prolex-Blue (Pro-Lab Diagnostics) and the comparators are Streptex (Murex), PathoDx (DPC), Streptococcus Grouping kit (Oxoid) and Prolex-White (Pro-Lab Diagnostics). A total of 302 consecutive clinical isolates are tested against all five kits, following the individual manufacturer's protocol, for both accuracy and speed. In addition, the data produced permits determination of the strengths or weaknesses of the kits against individual serotypes. Prolex-Blue proved to be both accurate and rapid, with a sensitivity of 99% and a specificity of 100%. Furthermore, average time to agglutination was substantially less than achieved by three of the other four kits evaluated.

Host defense in respiratory infections.

Respiratory defenses against infection involve a diverse and complex system. Mechanical barriers limit exposure of the respiratory tract to potential pathogenic organisms, whereas the mucociliary apparatus and cough reflexes work to expel any microbes that may bypass the initial defenses. When microorganisms have gained entry to the lower respiratory tract, the alveolar macrophage and recruited phagocytes may eliminate the culprits before active infection can be established. Only after the failure of the innate immune defenses is a specific immune response mounted. Examination of clinical defects in host defense allows one to understand the importance of the multitude of components of the lung's immune defense system.

Identifying all suspects: case studies.

Case presentations are one of the most instructive formats for learning. They allow the healthcare practitioner to identify and discuss patients who are at risk for a disease and then discuss appropriate therapy. Two patients who have dyslipidemia and are at risk for a coronary event are described here, along with treatment goals and options, audience responses, and discussions of appropriate therapy choices. Both patients require aggressive lipid management. One has had an angioplasty with placement of a stent. His case is an example of a patient at risk for a secondary coronary event; we refer to these cases as secondary-prevention patients. The other patient has high blood pressure and type 2 diabetes; her risk for a future coronary event based on Framingham risk data is greater than 20% in 10 years and therefore her risk for a future coronary event is equal to someone with established coronary heart disease (CHD). Her case is an example of what we refer to as a primary-prevention patient at high risk. Several large-scale primary- and secondary-prevention trials have demonstrated that aggressive lipid management can reduce the risk of future coronary events. In this supplement, we review some of those trials, the new guidelines, the concept of CHD-equivalent risk, and we will discuss the Framingham risk scoring system to predict the 10-year risk of coronary events in individual patients.

Keratinocyte growth factor attenuates hydrostatic pulmonary edema in an isolated, perfused rat lung model.

Hydrostatic pulmonary edema is a common complication of congestive heart failure, resulting in substantial morbidity and mortality. Keratinocyte growth factor (KGF) is a mitogen for type II alveolar epithelial and microvascular cells. We utilized the isolated perfused rat lung model to produce hydrostatic pulmonary edema by varying the left atrial and pulmonary capillary pressure. Pretreatment with KGF attenuated hydrostatic edema formation. This was demonstrated by lower wet-to-dry lung weight ratios, histological evidence of less alveolar edema formation, and reduced alveolar accumulation of intravascularly administered FITC-labeled large-molecular-weight dextran in rats pretreated with KGF. Thus KGF attenuates injury in this ex vivo model of hydrostatic pulmonary edema via mechanisms that prevent increases in alveolar-capillary permeability.

CD4+ lymphocyte responses to pulmonary infection with Mycobacterium tuberculosis in naïve and vaccinated BALB/c mice.

The Biostack experiments I and II were flown on board the Apollo 16 and 17 command modules in order to obtain information on the biological damage produced by the bombardment of heavy high-energy (HZE) particles of cosmic radiation during spaceflight. Such data are required for estimating radiation hazards in manned spaceflight. Seven biological systems in resting state (Bacillus subtilis spores, Colpoda cucullus cysts, Arabidopsis thaliana seeds, and eggs of Artemia salina, Tribolium castaneum and of Carausius morosus) were accommodated in the two Biostacks. By using a special sandwich construction of visual track detectors and layers of biological objects, identification of each hit biological object was achieved and the possible biological damage correlated with the physical features of the responsible HZE-particle. In the different systems the degree of damage depended on whether the hit cell was replaceable or not. A high sensitivity to HZE-particle bombardment was observed on Artemia salina eggs; 90% of the embryos, which were induced to develop from hit eggs, died at different developmental stages. Malformations of the abdomen or the extremities of the nauplius were frequently induced. In contrast, the growth of hit Vicia faba radiculae and the germination of hit Arabidopsis thaliana seeds and hit Bacillus subtilis spores were not influenced remarkably. But there was an increase in multicaulous plants and a reduction in the outgrowth of the bacteria] spores. In addition, information was obtained on the fluence of the HZE-particles, on their spectrum of charge and energy loss, and on the absorption by the Apollo spacecraft and the Biostack material itself. This will help to improve knowledge concerning radiation conditions inside of spacecrafts, necessary to secure a The Biostack experiments I and II were flown on board the Apollo 16 and 17 command modules in order to obtain information on the biological damage produced by the bombardment of heavy high-energy (HZE) particles of cosmic radiation during spaceflight. Such data are required for estimating radiation hazards in manned spaceflight. Seven biological systems in resting state (Bacillus subtilis spores, Colpoda cucullus cysts, Arabidopsis thaliana seeds, and eggs of Artemia salina, Tribolium castaneum and of Carausius morosus) were accommodated in the two Biostacks. By using a special sandwich construction of visual track detectors and layers of biological objects, identification of each hit biological object was achieved and the possible biological damage correlated with the physical features of the responsible HZE-particle. In the different systems the degree of damage depended on whether the hit cell was replaceable or not. A high sensitivity to HZE-particle bombardment was observed on Artemia salina eggs; 90% of the embryos, which were induced to develop from hit eggs, died at different developmental stages. Malformations of the abdomen or the extremities of the nauplius were frequently induced. In contrast, the growth of hit Vicia faba radiculae and the germination of hit Arabidopsis thaliana seeds and hit Bacillus subtilis spores were not influenced remarkably. But there was an increase in multicaulous plants and a reduction in the outgrowth of the bacteria] spores. In addition, information was obtained on the fluence of the HZE-particles, on their spectrum of charge and energy loss, and on the absorption by the Apollo spacecraft and the Biostack material itself. This will help to improve knowledge concerning radiation conditions inside of spacecrafts, necessary to secure a The Biostack experiments I and II were flown on board the Apollo 16 and 17 command modules in order to obtain information on the biological damage produced by the bombardment of heavy high-energy (HZE) particles of cosmic radiation during spaceflight. Such data are required for estimating radiation hazards in manned spaceflight. Seven biological systems in resting state (Bacillus subtilis spores, Colpoda cucullus cysts, Arabidopsis thaliana seeds, and eggs of Artemia salina, Tribolium castaneum and of Carausius morosus) were accommodated in the two Biostacks. By using a special sandwich construction of visual track detectors and layers of biological objects, identification of each hit biological object was achieved and the possible biological damage correlated with the physical features of the responsible HZE-particle. In the different systems the degree of damage depended on whether the hit cell was replaceable or not. A high sensitivity to HZE-particle bombardment was observed on Artemia salina eggs; 90% of the embryos, which were induced to develop from hit eggs, died at different developmental stages. Malformations of the abdomen or the extremities of the nauplius were frequently induced. In contrast, the growth of hit Vicia faba radiculae and the germination of hit Arabidopsis thaliana seeds and hit Bacillus subtilis spores were not influenced remarkably. But there was an increase in multicaulous plants and a reduction in the outgrowth of the bacteria] spores. In addition, information was obtained on the fluence of the HZE-particles, on their spectrum of charge and energy loss, and on the absorption by the Apollo spacecraft and the Biostack material itself. This will help to improve knowledge concerning radiation conditions inside of spacecrafts, necessary to secure a maximum possible protection to the astronauts.

Keratinocyte growth factor protects against Pseudomonas aeruginosa-induced lung injury.

We have previously reported that keratinocyte growth factor (KGF) attenuates alpha-naphthylthiourea-induced lung injury by upregulating alveolar fluid transport. The objective of this study was to determine the effect of KGF pretreatment in Pseudomonas aeruginosa pneumonia. A 5% bovine albumin solution with 1 microCi of (125)I-labeled human albumin was instilled into the air spaces 4 or 24 h after intratracheal instillation of P. aeruginosa, and the concentration of unlabeled and labeled proteins in the distal air spaces over 1 h was used as an index of net alveolar fluid clearance. Alveolocapillary barrier permeability was evaluated with an intravascular injection of 1 microCi of (131)I-albumin. In early pneumonia, KGF increased lung liquid clearance (LLC) compared with that in nonpretreated animals. In late pneumonia, LLC was significantly reduced in the absence of KGF but increased above the control value with KGF. KGF pretreatment increased the number of polymorphonuclear cells recovered in the bronchoalveolar lavage fluid and decreased bacterial pulmonary translocation. In conclusion, KGF restores normal alveolar epithelial fluid transport during the acute phase of P. aeruginosa pneumonia and LLC in early and late pneumonia. Host response is also improved as shown by the increase in the alveolar cellular response and the decrease in pulmonary translocation of bacteria.

Keratinocyte growth factor prevents ventilator-induced lung injury in an ex vivo rat model.

Mechanical ventilation has been shown to produce lung injury characterized by noncardiogenic pulmonary edema. Keratinocyte growth factor (KGF) is a heparin-binding growth factor that causes alveolar type II pneumocyte hyperplasia. KGF pretreatment and the resultant pneumocyte hyperplasia reduce fluid flux in models of lung injury. We utilized the isolated perfused rat lung model to produce lung injury by varying tidal volume and the level of positive end-expiratory pressure during mechanical ventilation. Pretreatment with KGF attenuated ventilator-induced lung injury (VILI). This was demonstrated by lower wet-to-dry lung weight ratios and less lung water accumulation in the KGF group. Further, KGF prevented the decline in dynamic compliance and alveolar protein accumulation in VILI. KGF pretreatment reduced alveolar accumulation of intravascularly administered fluorescein isothiocyanate-labeled high-molecular-weight dextran. Thus, pretreatment with KFG attenuates injury in this ex vivo model of VILI via mechanisms that prevent increases in permeability.

Ethanol and murine interleukin (IL)-12 production.

BACKGROUND: Interleukin (IL)-12 is a cytokine with protean effects against bacterial and intracellular pathogens. Induction of IL-12 at the time of infection has salient effects on elimination of various microbes. This work describes the effect of exposure to ethanol on lipopolysaccharide (LPS)-induced production of IL-12 in mice and whether ethanol-induced increases in IL-10 mediates these changes in IL-12 production. METHODS: BALB/c mice were pretreated with ethanol and then challenged with LPS either intravenously (iv) or intratracheally (it), and blood and lung production of IL-12 (p70 and p40 components) and serum IL-10 were assayed. Splenic and lung mRNA for IL-12 p35 and p40 components was determined. RESULTS: Ethanol pretreatment suppressed LPS-induced IL-12 p70 and p40 protein production in blood and lung. In spleen and lung, p40 mRNA was induced to a greater extent than p35 mRNA, and there was greater suppression of p40 mRNA compared with p35 mRNA in ethanol-treated animals. Ethanol up-regulated the production of IL-10, and pretreatment of these animals with a polyclonal anti-IL-10 antibody resulted in significant increases in IL-12 p70 and p40 levels, but not completely to those of control animals. CONCLUSIONS: Ethanol suppresses the production of murine IL-12 in response to LPS in blood and lung, with both the p70 and the p40 components affected. This suppression is accompanied by reductions of p40 mRNA in both spleen and lung. IL-10 may play a role in ethanol-induced suppression of IL-12, as neutralization of IL-10 partially attenuated the suppression of IL-12.

The role of the inflammatory response in chronic bronchitis: therapeutic implications.

Chronic bronchitis is diagnosed clinically by a chronic productive cough. As implied by the term "bronchitis," chronic airway inflammation is typically found in the central airways in patients with persistent cough and mucous hypersecretion. Although the exact pathogenesis of chronic bronchitis remains unclear, bacterial colonization and the resulting inflammatory response are thought to be of central importance. The generation of pro-inflammatory cytokines and chemotactic stimuli by the airway epithelium likely play central roles in propagating the inflammatory response in patients with chronic bronchitis. Further insights into the initiating events and underlying mechanisms that result in the clinical syndrome of chronic bronchitis will likely provide novel opportunities for therapeutic interventions.

Methicillin-resistant Staphyloccocus aureus: evaluation of five selective media.

This study evaluates the performance in isolating methicillin-resistant Staphylococcus aureus (MRSA) of three media: the reduced salt formulation of mannitol salt agar plus oxacillin (MMSAO); CHROMagar Staph aureus plus ciprofloxacin (CHRAC); and Halifax MRSA medium (HMO), against the previously recommended mannitol salt agar (7% salt) plus oxacillin (OMSAO) and Baird-Parker medium plus ciprofloxacin (BPC). MRSA screening swabs were plated out onto the five selective media and the plates examined at 24 and 48 h. Suspected colonies were confirmed as MRSA by detection of heat-labile DNase, coagulase and/or protein A, and by confirming resistance to methicillin. Of 719 specimens examined, 191 grew MRSA on at least one medium. The relative sensitivities of the five media at 48 h were as follows: BPC, 94%; CHRAC, 70%; OMSAO, 61%; HMO, 56%; and MMSAO, 46%. In addition, BPC gave the least number of unnecessary investigations for non-MRSA isolates. The current advantage of BPC when performing direct culture for MRSA was confirmed. The other ciprofloxacin-containing medium also produced reasonable results. Of the two mannitol salt agar media, the formulation with 7% salt gave better results. HMO proved unreliable at isolating MRSA.

The inflammatory response in chronic bronchitis.

Chronic bronchitis is diagnosed clinically by a chronic productive cough and is characterized by a variety of pathological changes, including bronchial gland hyperplasia, goblet cell metaplasia, and peribronchiolar fibrosis. As implied by the term ;;bronchitis,'' chronic airway inflammation is typically found in the central airways in patients with persistent cough and mucus hypersecretion. Although the exact pathogenesis of chronic bronchitis remains unclear, bacterial colonization and the resulting inflammatory response are thought to be of central importance. The generation of proinflammatory cytokines and chemotactic stimuli by the airway epithelium likely plays a central role in propagating the inflammatory response in patients with chronic bronchitis. Typically, an inflammatory mononuclear cell infiltrate is found in the airway wall, and the airway lumen is filled with neutrophils and their products. Further insights into the initiating events and underlying mechanisms that result in the clinical syndrome of chronic bronchitis will likely provide novel opportunities for therapeutic interventions.