Development of a Mycobacterium bovis intranasal challenge model in mice

Tuberculosis caused by infection with Mycobacterium tuberculosis or Mycobacterium bovis remains one of the most important infectious diseases of man and animals. The current vaccine, M. bovis bacille Calmette-Guérin (BCG) demonstrates variable efficacy in humans and cattle, and so an urgent need exists for a new vaccine to replace or supplement BCG. Novel vaccine development requires the availability of a suitable animal model in which to test potential vaccine candidates. Models for tuberculosis vaccine development include mice, guinea pigs, cattle and non-human primates. Murine models provide an economical and easily manipulated tool, but the natural aerosol infection route requires extensive facilities, equipment and validation. We sought to develop a logistically simpler intranasal M. bovis infection model for use in vaccine development for bovine tuberculosis. Intranasal M. bovis infection model in mice demonstrated distinct airway associated, dose related pathology, and was strikingly more virulent than previously employed intravenous infection with M. bovis. BCG vaccination of intranasal challenged mice induced 2 logs of protection with similar kinetics as those displayed in M. tuberculosis aerosol infection models. In conclusion, we report the development of a virulent, robust, stringent, physiological and inexpensive M. bovis intranasal infection model for the screening of potential vaccine candidates against bovine tuberculosis.     

Role of the ATP-binding cassette transporter Abcg2 in the phenotype and function of cardiac side population cells

Recently, the side population (SP) phenotype has been introduced as a reliable marker to identify subpopulations of cells with stem/progenitor cell properties in various tissues. We and others have identified SP cells from postmitotic tissues, including adult myocardium, in which they have been suggested to contribute to cellular regeneration following injury. SP cells are identified and characterized by a unique efflux of Hoechst 33342 dye. Abcg2 belongs to the ATP-binding cassette (ABC) transporter superfamily and constitutes the molecular basis for the dye efflux, hence the SP phenotype, in hematopoietic stem cells. Although Abcg2 is also expressed in cardiac SP (cSP) cells, its role in regulating the SP phenotype and function of cSP cells is unknown. Herein, we demonstrate that regulation of the SP phenotype in cSP cells occurs in a dynamic, age-dependent fashion, with Abcg2 as the molecular determinant of the cSP phenotype in the neonatal heart and another ABC transporter, Mdr1, as the main contributor to the SP phenotype in the adult heart. Using loss- and gain-of-function experiments, we find that Abcg2 tightly regulates cell fate and function. Adult cSP cells isolated from mice with genetic ablation of Abcg2 exhibit blunted proliferation capacity and augmented cell death. Conversely, overexpression of Abcg2 is sufficient to enhance cell proliferation, although with a limitation of cardiomyogenic differentiation. In summary, for the first time, we reveal a functional role for Abcg2 in modulating the proliferation, differentiation, and survival of adult cSP cells that goes beyond its distinct role in Hoechst dye efflux.     

Validation of the Social Appearance Anxiety Scale in Patients With Systemic Sclerosis: A Scleroderma Patient‐Centered Intervention Network Cohort Study

Objective

Systemic sclerosis (SSc) is an autoimmune disease that can cause disfiguring changes in appearance. This study examined the structural validity, internal consistency reliability, convergent validity, and measurement equivalence of the Social Appearance Anxiety Scale (SAAS) across SSc disease subtypes.

Methods

Patients enrolled in the Scleroderma Patient‐centered Intervention Network Cohort completed the SAAS and measures of appearance‐related concerns and psychological distress. Confirmatory factor analysis (CFA) was used to examine the structural validity of the SAAS. Multiple‐group CFA was used to determine whether SAAS scores can be compared across patients with limited and diffuse disease subtypes. Cronbach's alpha was used to examine internal consistency reliability. Correlations of SAAS scores with measures of body image dissatisfaction, fear of negative evaluation, social anxiety, and depression were used to examine convergent validity. SAAS scores were hypothesized to be positively associated with all convergent validity measures, with correlations significant and moderate to large in size.

Results

A total of 938 patients with SSc were included. CFA supported a 1‐factor structure (Comparative Fit Index 0.92, Standardized Root Mean Residual 0.04, and Root Mean Square Error of Approximation 0.08), and multiple‐group CFA indicated that the scalar invariance model best fit the data. Internal consistency reliability was good in the total sample (α = 0.96) and in disease subgroups. Overall, evidence of convergent validity was found with measures of body image dissatisfaction, fear of negative evaluation, social anxiety, and depression.

Conclusion

The SAAS can be reliably and validly used to assess fear of appearance evaluation in patients with SSc, and SAAS scores can be meaningfully compared across disease subtypes.

     

CE: Continuing Education article. Patient management in CKD stages 1 TO 3

This is the first article in a two-part Continuing Education (CE) series on the management of patients with Chronic Kidney Disease (CKD). CKD is now recognised as a global public health concern. It has been classified into five stages to assist healthcare professionals to care for patients presenting with this chronic illness. Numerous risk factors are associated with CKD including anaemia, hypertension and cardiovascular risk. Nephrology nurses play an important role in the monitoring and management of these factors along with educating patients and their families/carers to encourage self-management of their illness.     

Why Do Patients of Female Physicians Have Higher Rates of Breast and Cervical Cancer Screening?

OBJECTIVE: Women are more likely to receive breast and cervical cancer screening if they see female physicians. We studied whether this is due to differences between male and female physicians, or to differences in their patients. SETTING: Large midwestern, independent practice association style of health plan. DESIGN: We surveyed male and female primary care physicians matched for age and specialty and a stratified random sample of three of each physician's women patients. Physicians reported on their practice setting, their attitudes and practices regarding prevention, and their comfort and skill with various examinations. Patients reported on their sociodemographic characteristics, their attitudes and practices regarding prevention, and their preferences for physician gender. Claims data were used to calculate mammography and Pap smear screening rates for the physicians PARTICIPANTS: We studied 154 female and 190 male internists and family physicians and 794 of their patients. MEASUREMENTS AND MAIN RESULTS: We compared the responses of male and female physicians and their patients and used multivariable analysis to identify the patient and physician factors that accounted for the differences in screening rates between male and female physicians. Female physicians were more likely to ask new patients about components of prevention, to believe in the effectiveness of mammography, to feel more personal responsibility for ensuring that their patients received screening, and to report more comfort in performing Pap smears and breast examinations. Patients of female physicians were more educated and less likely to be married, but did not differ in other sociodemographic characteristics. They had similar attitudes and practices regarding prevention, except that patients of male physicians were more likely to smoke. Significantly more patients of female physicians preferred a female for some component of care. In multivariable analyses, practice organization, patient preference for a female physician, and prevention orientation of female physicians accounted for up to 40% of screening rate differences between female and male physicians for Pap smears, and 33% for mammography. CONCLUSIONS: Differences in beliefs of male and female physicians and patient preference for a female provider contribute independently to the higher rate of breast and cervical cancer screening by female physicians.     

N-Methyl-d-Aspartate-Stimulated Increases in Intracellular Calcium Exhibit Brain Regional Differences in Sensitivity to Inhibition by Ethanol

This study compared N -methyl- d -aspartate (NMDA)-stimulated increases in intracellular calcium in fura-2–loaded neurons dissociated from newborn rat brainstem (EC₅₀ in μM; 6.4), cerebellum (9.5), forebrain (6.3), and hippocampus (10.6). Ethanol inhibition of the response to 25 μM NMDA differed among the regions. The NMDA response in hippocampus was inhibited by 20 mM ethanol; cortex and cerebellum responses were inhibited by 80 mM ethanol, and no inhibition was seen in the brainstem. Addition of glycine (15 μM) failed to attenuate ethanol inhibition of the NMDA response. These results demonstrate that ethanol inhibition of NMDA-stimulated responses varies according to brain region. In contrast to previous findings from this laboratory using dissociated neurons from whole brain, the addition of glycine did not reverse the inhibitory effects of ethanol on NMDA-stimulated responses.     

Survival and cause-specific mortality in ulcerative colitis: follow-up of a population-based cohort in Copenhagen County

BACKGROUND & AIMS: A population-based cohort from Copenhagen County comprising 1160 patients diagnosed with ulcerative colitis between 1962 and 1987 was followed-up until 1997 to describe survival and cause-specific mortality. METHODS: Observed vs. expected deaths were presented as standardized mortality ratio (SMR) with exact 95% confidence intervals (CI) calculated by using individually registered person-years at risk and Danish 1995 mortality rates. Cumulative survival curves were calculated. RESULTS: A total of 261 deaths occurred, not significantly different from the expected number of 249 (SMR, 1.05; 95% CI, 0.92-1.19). The median age at death among men was 70 years (range, 6-96 years) and among women 74 years (range, 25-96 years). Twenty-five deaths (9.6%) were caused by complications to ulcerative colitis, mostly infectious and cardiovascular postoperative complications. Patients older than 50 years of age at diagnosis and with extensive colitis showed an increased mortality within the first 2 years because of ulcerative colitis-associated causes. The mortality from colorectal cancer was not increased and that of cancer in general was significantly lower than expected: 50 vs. 71 (SMR, 0.70; 95% CI, 0.52-0.93). A significantly increased mortality from pulmonary embolism and pneumonia was found. Among women only, death from genitourinary tract diseases and suicide was significantly increased. CONCLUSIONS: Despite an overall normal life expectancy for patients with ulcerative colitis, patients >50 years of age and with extensive colitis at diagnosis had increased mortality within the first 2 years after diagnosis, owing to colitis-associated postoperative complications and comorbidity.     

QT Interval in Patients with Unstable Angina and Non‐Q Wave Myocardial Infarction

Background: Non‐Q wave mvocardial infarction (NQMI) and unstable angina (UAP) have similar clinical presentations and similar ST‐T changes on the electrocardiogram. The purpose of this study was to assess whether changes in QT interval might help differentiating between these entities. Methods: The QT intervals of 52 patients hospitalized with NQMI were compared to those of 52 patients hospitalized for UAP. All patients had repeated ECG for at least 4 days. Results: Maximal QTc in patients with NQMI was significantly longer than in patients with UAP (475 vs 439 ms, P < 0.0001). QTc on the admission ECG was 450 ms in patients with NQMI compared to 417 ms in UAP P < 0.005). QTc > 460 ms was present in 48% patients with NQMI and in 19% of UAP patients. Maximal QT prolongation was observed within 36 hours of admission with return to normal within 96 hours. QT dispersion was within normal range, being longer in patients with NQMI than patients with UAP (55 vs 43 ms, P < 0.003). QT prolongation was not associated with increased frequency of arrhythmia. The cause of QT prolongation in NQMI may be related to the damage of subendocardial layer exposing the M cells layer which markedly prolong action potential duration. Conclusion: Transient QT prolongation is observed in about half of patients with NQMI. These ECG changes may help differentiating between patients with NQMI and UAP already on admission. A.N.E. 2002;7(4):343–348     

Heat shock protein 90 inhibition sensitizes acute myelogenous leukemia cells to cytarabine

Previous studies demonstrated that ataxia telangiectasia mutated- and Rad3-related (ATR) kinase and its downstream target checkpoint kinase 1 (Chk1) facilitate survival of cells treated with nucleoside analogs and other replication inhibitors. Recent results also demonstrated that Chk1 is depleted when cells are treated with heat shock protein 90 (Hsp90) inhibitor 17-allylamino-17-demethoxygeldanamycin (17-AAG). The present study examined the effects of 17-AAG and its major metabolite, 17-aminogeldanamycin (17-AG), on Chk1 levels and cellular responses to cytarabine in human acute myelogenous leukemia (AML) cell lines and clinical isolates. Cytarabine, at concentrations as low as 30 nM, caused activating phosphorylation of Chk1, loss of the phosphatase Cdc25A, and S-phase slowing. Conversely, treatment with 100 to 300 nM 17-AAG for 24 hours caused Chk1 depletion that was accompanied by diminished cytarabine-induced S-phase accumulation, decreased Cdc25A degradation, and enhanced cytotoxicity as measured by inhibition of colony formation and induction of apoptosis. Additional studies demonstrated that small inhibitory RNA (siRNA) depletion of Chk1 also sensitized cells to cytarabine, whereas disruption of the phosphatidylinositol 3-kinase (PI3k) signaling pathway, which is also blocked by Hsp90 inhibition, did not. Collectively, these results suggest that treatment with 17-AAG might represent a means of reversing checkpoint-mediated cytarabine resistance in AML.     

Transthoracic versus transesophageal echocardiography for detection of Libman-Sacks endocarditis: a randomized controlled study

OBJECTIVE: Libman-Sacks endocarditis in patients with systemic lupus erythematosus (SLE) is complicated with thromboembolism, severe valve regurgitation, need for high-risk valve surgery, or death. Transesophageal echocardiography (TEE) is highly accurate for detection of valvular heart disease, but there are no prospective randomized controlled series comparing transthoracic echocardiography (TTE) to TEE for detection of Libman-Sacks endocarditis. METHODS: Eighty-one patients with SLE (73 women, 8 men) with a mean age of 39 +/- 11 years and 75 healthy volunteers (40 women, 35 men) with a mean age of 35 +/- 9 years underwent paired TTE and TEE to detect valve vegetations, thickening, or >or= moderate mitral, tricuspid, or pulmonic >or= mild aortic regurgitation. Paired TTE and TEE studies of patients and controls were randomized and interpreted by an experienced observer unaware of subjects' data. RESULTS: Libman-Sacks endocarditis: (1) was more common in patients than in controls by both TTE and TEE (p < 0.001); and (2) was more commonly detected by TEE than by TTE (p 相似文献