Household deprivation, comorbidities and COVID-19 hospitalization in 690,115 children/adolescents

Background

Studies document that adults in disadvantaged socio-economic positions have elevated risks of a severe course of COVID-19, but it is unclear if this holds true for children. We investigate in this population-based study whether young people from socio-economically disadvantaged households in Germany had a higher risk of COVID-19 hospitalization compared with more affluent counterparts. We also examined if differences were related to comorbidities that predict severe courses in children.

Methods

We included data from all 690,115 children and adolescents (0-18 years) enrolled in a statutory health insurance carrier. Daily hospital diagnoses of COVID-19 were recorded from 1.1.2020 to 13.7.2021. Logistic regressions were used to compare children from households with an indication of poverty (e.g. long- or short-term unemployed) with children from households with insurance holders in regular employment. We also assessed socio-economic characteristics of the area of residence. We controlled for age, sex, days under observation, nationality, and comorbidities (e.g. obesity).

Findings

A COVID-19 hospital diagnosis was a rare event (n = 1637). Children of long-term unemployed parents had a 1·36 times (95% CI 1·21-1·51) higher adjusted odds of hospitalization compared with those of employed parents. Elevated odds were also found for short-term unemployed or low-wage employment. Those living in poor areas had a 3·02 (1·81-5·22) higher odds of hospitalization than those in less deprived areas. Comorbidities were strongly related to hospitalization, but their adjustment did not change main estimates for household deprivation.

Discussion

Results suggest that children from poor households are at higher risk of severe courses of COVID-19 than their affluent counterparts. This underlies the need to implement effective Public Health strategies to protect deprived children from COVID-19 and other infectious disease even in high income countries such as Germany.

Key messages

• Children and adolescents from poor families seem to be at higer risk for sever courses of COVID-19.

• Comorbidities were no key mediating factor in this study.

Underascertainment of COVID-19 cases among first responders: a seroepidemiological study

Background

Providing frontline support places first responders at a high risk for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

Aims

This study was aimed to determine the anti-SARS-CoV-2 seroprevalence in a cohort of first responders (i.e. firefighters/paramedics), to detect the underascertainment rate and to assess risk factors associated with seropositivity.

Methods

We conducted a serological survey among 745 first responders in Germany during 27 November and 4 December 2020 to determine the anti-SARS-CoV-2 seroprevalence using Elecsys® Anti-SARS-CoV-2 immunoassay (Roche Diagnostics, Mannheim, Germany). As part of the examination, participants were asked to provide information on coronavirus disease 2019 (COVID-19)-like-symptoms, information on sociodemographic characteristics and workplace risk factors for a SARS-CoV-2 infection and any prior COVID-19 infection. Descriptive statistics and logistic regression analysis were performed and seroprevalence estimates were adjusted for test sensitivity and specificity.

Results

The test-adjusted seroprevalence was 4% (95% CI 3.1–6.2) and the underascertainment rate was 2.3. Of those tested SARS-CoV-2 antibody positive, 41% were aware that they had been infected in the past. Seropositivity was elevated among paramedics who worked in the emergency rescue team providing first level of pre-hospital emergency care (6% [95% CI 3.4–8.6]) and those directly exposed to a COVID-19 case (5% [95% CI 3.5–8.1]). Overall, the seroprevalence and the underascertainment rate were higher among first responders than among the general population.

Conclusions

The high seroprevalence and underascertainment rate highlight the need to mitigate potential transmission within and between first responders and patients. Workplace control measures such as increased and regular COVID-19-testing and the prompt vaccination of all personnel are necessary.

[Specific components for integrative and flexible care models according to § 64b SGB V]

BACKGROUND

There is a need for a theoretical model for evaluating integrative and flexible care models according to § 64b of the Social Security Statutes Book V (SGB V).

MATERIAL AND METHODS

An iterative process of data collection and analysis has been executed according to grounded theory methodology.

RESULTS

A total of 11 specific components have been identified and shown to be robust and practicable and compatible with the data from the literature.

CONCLUSION

These components can be used for implementation, quality management and evaluation of projects for treatment models according to § 64b SGB V.

High efficacy of sofosbuvir/velpatasvir and impact of baseline resistance-associated substitutions in hepatitis C genotype 3 infection

BACKGROUND

Twelve weeks of the pangenotypic direct-acting antiviral (DAA) combination sofosbuvir/velpatasvir (SOF/VEL) was highly efficient in patients with hepatitis C virus (HCV) genotype 3 (GT3) infection in the ASTRAL-3 approval study. However, presence of resistance-associated substitutions (RASs) in the HCV nonstructural protein 5A (NS5A) was associated with lower treatment response.

AIM

To assess the efficacy and safety of SOF/VEL ± ribavirin (RBV) and the impact of NS5A RASs and RBV use on treatment outcome in HCV GT3 infection in a real-world setting.

METHODS

In this multicentre cohort study, GT3 patients from ten treatment centres across Germany were included. Sustained virological response was assessed 12 weeks after end-of-treatment (SVR12) in modified intention-to-treat (mITT) and per-protocol analysis (PP). NS5A RASs were tested by population-based sequencing.

RESULTS

A total of 293 GT3 patients were included. The median age was 48 years, 70% were male, 25.3% were cirrhotic, 9.2% were HCV/HIV co-infected and 21.8% were treatment-experienced, including 4.1% with DAA experience. Baseline NS5A RASs (Y93H, A30K, L31M) were detected in 11.2%. RBV was added in 5% of noncirrhotic and 58.9% of cirrhotic patients, respectively. SVR12 rates for SOF/VEL±RBV were 95.9% (mITT) and 99.5% (PP), respectively. Only 1 virological relapse occurred in a cirrhotic patient previously treated with SOF/RBV. No treatment-related major adverse events occurred.

CONCLUSION

Twelve weeks of SOL/VEL±RBV was safe and highly efficient in HCV GT3 across a diverse patient population. Baseline NS5A RASs were rarely observed and presence did not seem to impact SVR, regardless of the use of RBV.

Outcome of a hepatitis B vaccination program for clients of a drug consumption facility

BACKGROUND

Intravenous drug users (IDUs) are a risk group for hepatitis B. In Germany, the hepatitis B virus (HBV) vaccination rates in IDUs are low.

OBJECTIVES

In this study the implementation and success of HBV vaccination in a drug consumption facility (DCF) was evaluated.

STUDY DESIGN

Clients attending a DCF were asked regarding their HBV status. In case of no known HBV infection and no previous vaccination, clients interested in HBV vaccination were offered a HBV blood testing. HBV vaccination was administered to susceptible clients in months 0, 1, 6. Booster vaccinations were offered to clients without seroconversion (anti-HBs < 100 U/l).

RESULTS

193 out of 364 clients reported on a known HBV infection or immunity after vaccination. 95 (55.6%) out of 171 eligible clients underwent a HBV serology. According to HBV serology 31 (32.6%) out of 95 clients were not susceptible for vaccination (mainly due to an unknown HBV infection). 47 (73.4%) out of 64 clients susceptible were administered 3 vaccinations. 10 clients received at least one further vaccination. For those showing up for testing (36 out of 47 clients) the seroconversion rate was 69.4% (> 100 IU/l) and 83.3% (> 10 IU/l), respectively.

DISCUSSION

Only a minority of clients of a DCF was susceptible for HBV vaccination. 47 out of 64 (73.4%) susceptible clients underwent at least three administrations of the vaccine, mostly resulting in seroconversion. Even in IDUs attending a DCF, a clientele with unstable social and health conditions, HBV vaccination can be carried out successfully.

The CO dehydrogenase accessory protein CooT is a novel nickel-binding protein

In Rhodospirillum rubrum, maturation of Carbon Monoxide Dehydrogenase (CODH) requires three accessory proteins, CooC, CooT and CooJ, dedicated to nickel insertion into the active site, which is constituted by a distorted [NiFe₃S₄] cubane coordinated with a mononuclear Fe site. CooC is an ATPase proposed to provide the energy required for the maturation process, while CooJ is described as a metallochaperone with 16 histidines and 2 cysteines at the C-terminus, likely involved in metal binding and/or storage. Prior to the present study, no information was available on CooT at the molecular level. Here, the X-ray structure of RrCooT was obtained, which revealed that this protein is a homodimer featuring a fold that resembles an Sm-like domain, suggesting a role in RNA metabolism that was however not supported by experimental observations. Biochemical and biophysical evidence based on circular dichroism spectroscopy, light scattering, isothermal titration calorimetry and site-directed mutagenesis showed that RrCooT specifically binds a single Ni(ii) per dimer, with a dissociation constant of 9 nM, through the pair of Cys2, highly conserved residues, located at the dimer interface. Despite its role in the activation of RrCODH in vivo, CooT was thought to be a unique protein, found only in R. rubrum, with an unclear function. In this study, we extended the biological impact of CooT, establishing that this protein is a member of a novel Ni(ii)-binding protein family with 111 homologues, linked to anaerobic metabolism in bacteria and archaea, and in most cases to the presence of CODH.

Treatment of fulminant acute Hepatitis B with nucles(t)id analogues is safe and does not lead to secondary chronification of Hepatitis B

Background: Acute hepatitis B virus (HBV) infection is still a major cause of acute liver failure (ALF), necessitating a high rate of emergency liver transplantation (LTx). Acute infection is followed by high viral replication rates leading to hepatocyte death and, ultimately, ALF. The objective of treating HBV-induced ALF thus is to eliminate, or significantly suppress, HBV replication and therefore reduce cell death and support regeneration. Objective: In this retrospective study, we want to evaluate the timing, the safety, and the long-term virological outcome of this approach. Methods/results: In this study, we included 32 patients (16 female and 16 males; median age 39.5 years) with ALF due to hepatitis B, who were transferred to the university hospital Essen, Germany between January 2009 and December 2013. Before treatment, transaminases were highly elevated, bilirubin was increased, and elevated international normalized ratio (INR) revealed impaired liver function. HBV-DNA and HBsAg were positive. All 32 patients received oral antiviral treatment (3 lamivudine, 21 entecavir, and 8 tenofovir) between 1 day and 4 months after diagnosis of acute hepatitis B. One patient died, 2 were transplanted, one died shortly after LTx the other patient survived after LTx. These 3 patients received treatment in a state of advanced liver failure, and 1 patient 4 months after initial diagnosis of hepatitis B. Twenty-nine patients survived without LTx. Five patients were discharged without further follow-up. All 24 remaining patients became HBV-DNA negative in median of 100 days. Twenty-two patients were followed further, and all patients lost their HBsAg in median of 108 days. Sixteen of the 22 patients experienced a seroconversion to anti-HBs in median of 137 days. Four patients who were followed for 1 more year after HBsAg did not develop anti-HBs. None of the patients developed chronic hepatitis B. Conclusion: Immediate treatment of HBV-induced ALF with nucleos(t)id-analogues (NUCs) appears save and prevents LTx and death, and there is no indication for increased chronicity.

Evaluation of an integrated care program for schizophrenia: concept and study design

Concept and design of an independent scientific evaluation of different pathways of care for schizophrenia patients in Germany with respect to effectiveness and efficiency are presented. In this prospective, observational study, schizophrenia patients receiving an integrated care treatment, the intervention group (IG), are compared with patients under routine care conditions treated by the same physician (first control group, CG 1). A second control group (CG 2) of patients treated by office-based psychiatrists not participating in the integrated care program will be recruited and their data compared with the two other groups. The total amount of psychiatric hospital days after 12 months is defined as primary outcome parameter. Secondary outcome parameters comprise the frequency of psychiatric inpatient readmissions, severity of schizophrenia symptoms, remission rates and quality of life. Patients undergo assessments at baseline, month 6 and 12 using standardized and experimental questionnaires. Routine data of a regional German social health insurance fund complement information on included patients. Additionally, a cost-effectiveness and cost-utility analysis will be performed. Until now, 137 psychiatrists included 980 patients in the integrated care project in Lower Saxony, Germany, and 47 psychiatrists (IG and both CGs) are willing to participate in the independent evaluation. For the first time, a prospective observational controlled evaluation study of a countrywide integrated care project planning to recruit 500 schizophrenia patients has started using comprehensive assessments as well as routine data of a social health insurance fund.

[HCV reinfection after liver transplantation - management and first experiences with telaprevir-based triple therapy]

BACKGROUND AND OBJECTIVE

The management of hepatitis C virus (HCV) recurrence after liver transplantation (LTx) is a major challenge in patient care. For patients with HCV GT1, treatment standard with pegylated interferon (PEG-IFN) and ribavirin (RBV) has been augmented in 2011 by first generation protease inhibitors (PI), telaprevir (TVR) and boceprevir (BOC). We report our first experiences with TVR-based triple therapy in patients with GT1-reinfection of the graft.

PATIENTS AND METHOD

13 patients with histologically proven HCV GT1-reinfection of the graft received 12 weeks of PEG-IFN/RBV/TVR followed by 12 weeks of PEG-IFN/ RBV only. During the triple therapy phase immune suppression was tightly monitored, and the patients were also closely monitored for side effects.

RESULTS

The dosage of immunosuppressants had to be reduced significantly (TAC: 30-fold; CSA 3,5-fold). Stable levels were achieved by daily or over-daily dosing of a special size application of 0,1 mg tacrolimus (Tac) bid or a minimal dose of 10 mg cyclosporine (CSA) bid or qd, respectively. In all patients hematological side effects were observed, 65 % of which required RBV dose reduction, administration of erythropoietin or blood transfusions. Increase of kidney retention values requiring infusions occurred in 50 %. All side effects were reversible. There were no early discontinuations of therapy. An early viral response (EVR) with viral decline below limit of detection was noted at week 12 in 9/13 patients and at week 12 in further 3 patients.

CONCLUSION

Our preliminary results show high EVR response rates of TVR-based triple therapy in LTx patients with HCV-GT1 re-infection.

A patient with severe respiratory failure caused by novel human coronavirus

We report a case of a 45-year-old patient who developed severe acute respiratory distress syndrome accompanied by renal failure. An infection with a novel human coronavirus was confirmed and found to be the reason for rapidly progressive respiratory failure of our patient.

Assays for laboratory confirmation of novel human coronavirus (hCoV-EMC) infections

We present a rigorously validated and highly sensitive confirmatory real-time RT-PCR assay (1A assay) that can be used in combination with the previously reported upE assay. Two additional RT-PCR assays for sequencing are described, targeting the RdRp gene (RdRpSeq assay) and N gene (NSeq assay), where an insertion/deletion polymorphism might exist among different hCoV-EMC strains. Finally, a simplified and biologically safe protocol for detection of antibody response by immunofluorescence microscopy was developed using convalescent patient serum.

An empiric analysis of omaha system targets

Interface terminologies used in electronic health records must be re-evaluated and revised to reflect current health care practice and knowledge. To enable future revisions of the Omaha System Intervention Scheme, investigators evaluated formal semantic structure of target terms and concept duplication of problem and target terms. Using linguistic principles and qualitative analysis, five themes were found. A multidimensional formal semantic structure for the intervention target term was proposed. Concept duplication was examined for 16 problem-target matches. Clinical data enabled assessment of the validity of a proposed formal semantic structure and concept duplication. Recommendations are suggested for future development of the Omaha System Intervention Scheme.

[Bremen Risk Assessment Scale for General Psychiatry. Predicting violent behavior in mentally ill patients discharged from general psychiatry]

BACKGROUND

In order to identify psychiatric patients who have a higher risk of being aggressive towards others, a risk checklist, the "Bremen Risk Assessment Scale for General Psychiatry" (BRAS-GP) was developed. The results of the first trial are described in this article.

METHODS

In this prospective study all in-patients who were treated in the last quarter of 2006 were included. The BRAS-GP was applied on discharge to patients who were treated involuntarily. In a 1-year follow-up all patients who had been readmitted were analyzed to assess if any aggressive incident had occurred to confirm or refute the prognoses.

RESULTS

On evaluation of the readmissions data, we calculated sensitivity of 0.72 and specificity of 0.71 as well as an "area under the curve" of 0.74. Especially during the first months after discharge readmissions linked with aggressive behavior were observed.

CONCLUSION

The BRAS-GP is a useful prognostic instrument with high predictive validity. It can be easily applied in general psychiatric wards to help identify risk patients. After detecting risk patients special treatment strategies can then be offered.

Characterization of CD8+ T-cell response in acute and resolved hepatitis A virus infection

BACKGROUND & AIMS

In contrast to the infection with other hepatotropic viruses, hepatitis A virus (HAV) always causes acute self-limited hepatitis, although the role for virus-specific CD8 T cells in viral containment is unclear. Herein, we analyzed the T cell response in patients with acute hepatitis by utilizing a set of overlapping peptides and predicted HLA-A2 binders from the polyprotein.

METHODS

A set of 11 predicted peptides from the HAV polyprotein, identified as potential binders, were synthesized. Peripheral blood mononuclear cells (PBMCs) from patients were tested for IFNγ secretion after stimulation with these peptides and ex vivo with HLA-A2 tetramers. Phenotyping was carried out by staining with the activation marker CD38 and the memory marker CD127.

RESULTS

Eight out of 11 predicted HLA-A2 binders showed a high binding affinity and five of them were recognized by CD8+ T cells from patients with hepatitis A. There were significant differences in the magnitude of the responses to these five peptides. One was reproducibly immunodominant and the only one detectable ex vivo by tetramer staining of CD8+ T cells. These cells have an activated phenotype (CD38hi CD127lo) during acute infection. Three additional epitopes were identified in HLA-A2 negative patients, most likely representing epitopes restricted by other HLA-class I-alleles (HLA-A11, B35, B40).

CONCLUSIONS

Patients with acute hepatitis A have a strong multi-specific T cell response detected by ICS. With the tetramer carrying the dominant HLA-A2 epitope, HAV-specific and activated CD8+ T cells could be detected ex vivo. This first description of the HAV specific CTL-epitopes will allow future studies on strength, breadth, and kinetics of the T-cell response in hepatitis A.

Characterization of full-length hepatitis C virus genotype 4 sequences

Over 85% of the world's nearly 170 million hepatitis C virus (HCV)-infected subjects exist in regions of Africa, Southeast Asia and Middle Eastern countries where genotypes 4-6 are very common. In particular, HCV genotype 4 is highly prevalent in Egypt with more than 19% of the population infected and chronic HCV representing one of the top five leading causes of death, due in part to ineffective interferon alpha treatment against this genotype. Despite this, very little work has been carried out to characterize the sequence diversity of genotype 4, which will be critical to the development of effective vaccines and antiviral therapies against this genotype. As a result of the paucity of sequence data available for HCV genotype 4, for which only one full genome sequence is currently available, we were interested in characterizing additional genotype 4 sequences and to provide reagents for amplification of this genotype. Here we describe seven unique HCV genotype 4a full genomes, in addition to a single genotype 4d genome, and characterize their sequence diversity in relation to other more closely characterized HCV genotypes.

Effects of acetylsalicylic acid on ascorbic acid concentrations in plasma, gastric mucosa, gastric juice and urine--a double-blind study in healthy subjects

OBJECTIVE

This study investigated concentrations of ascorbic acid (ASC) in gastric mucosa, gastric juice, urine and plasma in healthy subjects under steady state and fasted conditions with and without concomitant administration of acetylsalicylic acid (ASA).

MATERIAL AND METHODS

This was a prospective, randomized, double-blind, parallel-group study in healthy subjects. It has assessed the effects of a 6-day administration of 0.8 g ASA or 0.48 g ASC, 3 times daily and the combination of both on concentrations of ASC in gastric mucosa, gastric juice, urine and plasma. Treatments were switched after 6 days without any washout for assessment of compartment sensitivity to changes in study medication resulting in an overall 14-day study period. Each of the 3 treatment groups consisted of 15 subjects.

RESULTS

ASC concentrations were highest in the gastric mucosa (251+/-11 microg/g), followed by gastric juice (29+/-6 microg/ml), plasma (10+/-0.2 microg/ml), and urine (5+/-1 microg/ml). On day 7, ASC concentrations in gastric mucosa, plasma and urine had increased in those groups receiving ASC and decreased in the group receiving ASA only. All differences were statistically significant and indicate an interaction with ASA. In gastric juice, differences in ASC concentrations between the treatment groups were not statistically significant between baseline and day 7. ASC concentrations in plasma were strongly correlated with corresponding ASC concentrations in gastric mucosa (r = 0.34) and urine (r = 0.83), as were ASC concentrations in gastric mucosa with ASC in urine (r = 0.28).

CONCLUSIONS

The gastric mucosa is the largest depot of ASC in the human body with ASC concentrations 25 times higher than in plasma. In healthy subjects, clinically relevant doses of ASA reduced ASC concentrations in gastric mucosa by about 10% within 6 days resulting from antioxidative defense mechanisms. In patients with long-term ASA treatment or conditions with additional risks such as elderly subjects with unfavorable dietary conditions and impaired antioxidative protection, a protective adjunct administration of ASC appears to be beneficial.

Effects of buffered and plain acetylsalicylic acid formulations with and without ascorbic acid on gastric mucosa in healthy subjects

BACKGROUND

The most frequently reported adverse events associated with acetylsalicylic acid intake are minor gastrointestinal complaints. Galenic modifications, such as buffered formulations with or without ascorbic acid, may improve the benefit-risk ratio by decreasing the local mucosal side-effects of acetylsalicylic acid.

AIM

To assess endoscopically-proven gastrointestinal lesions and the amount of gastric microbleeding of four different buffered and plain acetylsalicylic acid formulations, one containing paracetamol.

METHODS

A randomized, four-fold cross-over study was performed in 17 healthy subjects who underwent serial oesophago-gastro-duodenoscopy before and after each course of 4-day dosing. Gastric aspirates were collected for the determination of haemoglobin concentrations to detect microbleeding.

RESULTS

Buffered acetylsalicylic acid plus ascorbic acid yielded the lowest Lanza score, the lowest increase in the number of mucosal petechiae and the lowest increase in the amount of gastric microbleeding. Subjects receiving acetylsalicylic acid plus paracetamol plus caffeine showed the highest Lanza score of all treatments, and a considerably greater sum of petechiae in the oesophagus, stomach and duodenum compared with those receiving buffered acetylsalicylic acid plus ascorbic acid.

CONCLUSIONS

The trial confirms that buffering of acetylsalicylic acid improves local gastric tolerability. Acetylsalicylic acid in combination with ascorbic acid shows significantly fewer gastric lesions and the lowest increase in gastric microbleeding compared with the other tested formulations.

Biomonitoring on carcinogenic metals and oxidative DNA damage in a cross-sectional study

Oxidative DNA damage is mediated by reactive oxygen species and is supposed to play an important role in various diseases including cancer. The endogenous amount of reactive oxygen species may be enhanced by the exposure to genotoxic metals. A cross-sectional study was conducted from 1993 to 1994 in an urban population in Germany to investigate the association between metal exposure and oxidative DNA damage. The cross-sectional sample of 824 participants was recruited from the registry of residents in Bremen, comprising about two-third males and one-third females with an average age of 61.1 years. A standardized questionnaire was used to obtain the occupational and smoking history. The incorporated dose of exposure to metals was assessed by biological monitoring. Chromium, cadmium, and nickel were measured in 593 urine samples. Lead was determined in blood samples of 227 participants. As a biomarker for oxidative DNA damage, 7,8-dihydro-8-oxoguanine has been analyzed in lymphocytes of 201 participants. Oxidative lesions were identified by single strand breaks induced by the bacterial formamidopyrimidine-DNA glycosylase (Fpg) in combination with the alkaline unwinding approach. The concentrations of metals indicate a low body load (median values: 1.0 microg nickel/l urine, 0.4 microg cadmium/l urine, and 46 microg lead/l blood; 83% of chromium measures were below the technical detection limit of 0.3 microg/l). The median level of Fpg-sensitive DNA lesions was 0.23 lesions/10(6) bp. A positive association between nickel and the rate of oxidative DNA lesions (Fpg-sensitive sites) was observed (odds ratio, 2.15; tertiles 1 versus 3, P < 0.05), which provides further evidence for the genotoxic effect of nickel in the general population.

Structure and promoter activity of the mouse CDC25A gene

CDC25A is a member of a group of highly related, dual-specificity phosphatases that promote cell cycle phase transitions by regulating the activity of cyclin-dependent kinases. Here we report the cloning and genomic sequence of 21,067 nucleotides encompassing the mouse CDC25A gene. The coding sequence is expressed from 17,904 bp of genomic DNA comprising 15 exons. We also mapped the transcription initiation site to a consensus initiator element proximal to an SP1 site. Approximately 1 kb of sequence upstream of the transcription initiation site confers promoter activity and cell type specificity to a reporter gene construct. Surprisingly, transcription from this promoter was repressed by over-expression of catalytically active but not catalytically inactive CDC25A protein. We also show, using NIH 3T3 cells, that murine CDC25A mRNA levels fluctuate only modestly over the cell cycle. Our findings provide insights into the regulation of CDC25A expression and have facilitated construction of gene knock-out vectors.

Microcomputer education for nursing: an approach to microcomputer education in a large tertiary care center

Communication skills needed for the healthcare environment are changing. In the past, poor reading and writing skills made it difficult to use a paper chart. Current computer technology provides many new opportunities for communicating in the clinical setting. Computer literacy has become a necessary skill for efficient use of clinical computer systems. At this large tertiary care setting, a survey was developed and distributed to staff to assess learner needs. Nursing staff identified educational needs for basic computer knowledge, the ability to move between computer functions, and the skills to navigate through specific applications. Based on survey analysis, three educational classes were constructed that addressed the department's specific needs.

Extra and intracellular expression of Mycobacterium tuberculosis genes

To understand how Mycobacterium tuberculosis survives and grows in an infected host, we are studying the mycobacterial transcriptional machinery and its response to stresses encountered in vitro and in vivo. Much has been learned about sigma factors and other transcriptional regulators concerning their roles in controlling mycobacterial gene expression. It has recently been shown that sigma A is the essential housekeeping sigma factor and the alternative sigma factor sigma B, not essential for growth in a laboratory setting, is required for a robust protective response to various environmental stresses. We are also studying the mechanism by which the R522H mutation in sigma A prevents the transcription of certain genes, including some that are believed necessary for virulence. Also under investigation is the mycobacterial iron acquisition apparatus and its regulation, as metabolism of this essential element plays a key role in microbial pathogenesis. We have identified and characterized the major mycobacterial iron regulator IdeR that blocks the synthesis of the iron uptake machinery and have identified target genes in M. smegmatis and M. tuberculosis that are directly repressed by IdeR. Recent studies have examined the control of M. tuberculosis gene expression in vivo. Among these new approaches are an in vivo expression technology system to identify M. tuberculosis genes that are induced in macrophages and mice and a novel RT-PCR method that allows an accurate comparison between the levels of specific mRNAs in M. tuberculosis grown in vitro with those found in bacteria growing in human macrophages.

Transcriptional control of the iron-responsive fxbA gene by the mycobacterial regulator IdeR

Exochelin is the primary extracellular siderophore of Mycobacterium smegmatis, and the iron-regulated fxbA gene encodes a putative formyltransferase, an essential enzyme in the exochelin biosynthetic pathway (E. H. Fiss, Y. Yu, and W. R. Jacobs, Jr., Mol. Microbiol. 14:557-569, 1994). We investigated the regulation of fxbA by the mycobacterial IdeR, a homolog of the Corynebacterium diphtheriae iron regulator DtxR (M. P. Schmitt, M. Predich, L. Doukhan, I. Smith, and R. K. Holmes, Infect. Immun. 63:4284-4289, 1995). Gel mobility shift experiments showed that IdeR binds to the fxbA regulatory region in the presence of divalent metals. DNase I footprinting assays indicated that IdeR binding protects a 28-bp region containing a palindromic sequence of the fxbA promoter that was identified in primer extension assays. fxbA regulation was measured in M. smegmatis wild-type and ideR mutant strains containing fxbA promoter-lacZ fusions. These experiments confirmed that fxbA expression is negatively regulated by iron and showed that inactivation of ideR results in iron-independent expression of fxbA. However, the levels of its expression in the ideR mutant were approximately 50% lower than those in the wild-type strain under iron limitation, indicating an undefined positive role of IdeR in the regulation of fxbA.

Outbreaks of Staphylococcus aureus infections during treatment of late onset pneumonia with ciprofloxacin in a prospective, randomized study

We carried out a prospective, randomized four-center study in nosocomial pneumonia to evaluate the clinical and microbiological efficacy and safety of different treatment regimens in adult intensive care patients. During the randomized treatment of 18 patients with late onset pneumonia, ciprofloxacin (CIP) was compared to ceftazidim plus gentamicin (CAZ/GM), outbreaks of Staphylococcus aureus infections occurred in center 1. This article reports the unexpected findings. In the CIP group six out of ten patients were superinfected or reinfected with ciprofloxacin-resistant pathogens at the follow-up on day 5 after treatment. Four out of these six patients were superinfected with methicillin-susceptible or methicillin-resistant S. aureus (MRSA). Four superinfected patients died with pneumonia during treatment or before the follow-up. In the CAZ/GM group one out of eight patients was superinfected with MRSA. One patient died with pneumonia during treatment. There was no problem with multiresistant S. aureus or MRSA before the study period in center 1. In conclusion, we observed outbreaks of S. aureus infections during the treatment of late onset pneumonia with ciprofloxacin, which were associated with a high mortality. These superinfections occurred in mechanically ventilated, postoperative cardiac surgical patients after 13 days in the intensive care unit (ICU). We recommend combining ciprofloxacin with an antibiotic agent active against gram-positive bacteria in ventilator-associated pneumonia after a prolonged ICU stay. Selective pressure of ciprofloxacin could have played a role in these superinfections.

H2 receptor-mediated facilitation and H3 receptor-mediated inhibition of noradrenaline release in the guinea-pig brain

The effect of histamine and related drugs on the tritium overflow evoked electrically (0.3 Hz) or by introduction of Ca2+ ions into Ca2+-free K+-rich (25 mmol/l) medium containing tetrodotoxin was studied in superfused guinea-pig brain cortex, cerebellum, hippocampus or hypothalamus slices and in mouse brain cortex slices preincubated with 3H-noradrenaline. The electrically evoked tritium overflow in guinea-pig cortex slices was inhibited by histamine; the H3 receptor antagonist clobenpropit reversed the effect of histamine to a slight facilitation. The facilitatory effect of histamine (obtained in the presence of clobenpropit) was not affected by the H1 receptor antagonist mepyramine but abolished by the H2 receptor antagonist ranitidine. In the absence of clobenpropit, ranitidine augmented the inhibitory effect of histamine. In slices superfused in the presence of ranitidine, the evoked overflow was inhibited by histamine and, more potently, by the H3 receptor agonist R-alpha-methylhistamine in a concentration-dependent manner (maximum inhibitory effect obtained for both agonists 30-35%). The concentration-response curve of histamine was shifted to the right by the H3 receptor antagonist thioperamide. R-alpha-methylhistamine inhibited the electrically evoked tritium overflow also in guinea-pig cerebellar, hippocampal and hypothalamic slices. In cortex slices superfused in the presence of clobenpropit, the H2 receptor agonists impromidine and, less potently, R-sopromidine facilitated the evoked overflow in a concentration-dependent manner. S-Sopromidine only tended to increase the evoked overflow. The effect of impromidine was counteracted by the H2 receptor antagonists ranitidine and cimetidine. The extent of the maximum facilitatory effect of impromidine (by 15-20%) was about the same when (i) the Ca2+ concentration in the medium was reduced from 1.3 to 0.98 mmol/l, (ii) the time of exposure to impromidine was reduced from 28 to 8 min or (iii) cerebellar, hippocampal or hypothalamic slices were used instead of cortical slices. The Ca2+-induced tritium overflow in guinea-pig cortex slices was inhibited by histamine (in the presence of ranitidine); this effect was abolished by clobenpropit. In slices superfused in the presence of clobenpropit, impromidine failed to facilitate the Ca2+-evoked tritium overflow. The electrically evoked tritium overflow in mouse brain cortex slices was inhibited by histamine by about 60% (both in the absence or presence of ranitidine). The inhibitory effect of histamine was abolished (but not reversed) by clobenpropit. In conclusion, noradrenaline release in the guinea-pig brain cortex is inhibited via presynaptic H3 receptors and facilitated via H2 receptors not located presynaptically. In the mouse brain cortex, only inhibitory H3 receptors occur. The extent of the H3 receptor-mediated effect is more marked in the mouse than in the guinea-pig brain cortex.

Cannabinoid CB1 receptor-mediated inhibition of noradrenaline release in the human and guinea-pig hippocampus

We examined the question of whether cannabinoid receptors modulating noradrenaline release are detectable in the brain of humans and experimental animals. For this purpose, hippocampal slices from humans, guinea-pigs, rats and mice and cerebellar, cerebrocortical and hypothalamic slices from guinea-pigs were incubated with [3H]noradrenaline and then superfused. Tritium overflow was evoked either electrically (0.3 or 1 Hz) or by introduction of Ca2+ ions (1.3 mM) [corrected] into Ca(2+)-free, K(+)-rich medium (25 mM) [corrected] containing tetrodotoxin 1 microM. Furthermore, the cAMP accumulation stimulated by forskolin 10 microM was determined in guinea-pig hippocampal membranes. We used the following drugs: the cannabinoid receptor agonists (-)-cis-3-[2-hydroxy-4-(1,1- dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclo-hexanol (CP-55,940) and R(+)-[2,3-dihydro-5-methyl-3- [(morpholinyl)methyl]pyrrolo[1,2,3-de]-1,4-benzoxazinyl]- (1-naphthalenyl)methanone (WIN 55,212-2), the inactive S(-)-enantiomer of the latter (WIN 55,212-3) and the CB1 receptor antagonist N-piperidino-5-(4-chlorophenyl)- 1-(2,4-dichlorophenyl)-4-methyl-3-pyrazole-carboxamide (SR 141716). The electrically evoked tritium overflow from guinea-pig hippocampal slices was reduced by WIN 55,212-2 (pIC30% 6.5) but not affected by WIN 55,212-3 up to 10 microM. The concentration-response curve of WIN 55,212-2 was shifted to the right by SR 141716 (0.032-microM) (apparent pA2 8.2), which by itself did not affect the evoked overflow. WIN 55,212-2 1 microM also inhibited the Ca(2+)-evoked tritium overflow in guinea-pig hippocampal slices and the electrically evoked overflow in guinea-pig cerebellar, cerebrocortical and hypothalamic slices as well as in human hippocampal slices but not in rat and mouse hippocampal slices. SR 141716 (0.32 microM) markedly attenuated the WIN 55,212-2-induced inhibition in guinea-pig and human brain slices. SR 141716 0.32 microM by itself increased the electrically evoked tritium overflow in guinea-pig hippocampal slices but failed to do so in slices from the other brain regions of the guinea-pig and in human hippocampal slices but failed to do so in slices from the other brain regions of the guinea-pig and in human hippocampal slices. The cAMP accumulation stimulated by forskolin was reduced by CP-55,940 and WIN 55,212-2. The concentration-response curve of CP 55,940 was shifted to the right by SR 141716 (0.1 microM; apparent pA2 8.3), which by itself did not affect cAMP accumulation. In conclusion, cannabinoid receptors of the CB1 subtype occur in the human hippocampus, where they may contribute to the psychotropic effects of cannabis, and in the guinea-pig hippocampus, cerebellum, cerebral cortex and hypothalamus. The CB1 receptor in the guinea-pig hippocampus is located presynaptically, is activated by endogenous cannabinoids and may be negatively coupled to adenylyl cyclase.

Purification and properties of the Mycobacterium smegmatis mc(2)155 beta-lactamase

The beta-lactamase of Mycobacterium smegmatis mc(2)155 has been purified to protein homogeneity. Its N-terminal sequence and catalytic properties are similar to those of the beta-lactamase produced by Mycobacterium fortuitum D316 and establish this new enzyme as a member of molecular class A.

Cannabinoid receptor-mediated inhibition of dopamine release in the retina

The possible occurrence of cannabinoid (CB) receptors was studied on superfused guinea-pig retinal discs preincubated with [3H]dopamine or [3H]noradrenaline. Tritium overflow was evoked either electrically (3 Hz) or by re-introduction of Ca2+ 1.3 mM after superfusion with Ca(2+)-free medium containing K+ 30 mM. The accumulation of [3H]dopamine ([3H]DA) and [3H]noradrenaline ([3H]NA) was inhibited by the selective inhibitor of the neuronal dopamine transporter GBR-12909 (pIC50% 7.29 and 7.41, respectively) but not by the selective inhibitor of the neuronal noradrenaline transporter desipramine (1 microM). The electrically or Ca(2+)-evoked tritium overflow in retinal discs preincubated with [3H]DA or [3H]NA was reduced by the CB receptor agonists CP-55,940 and WIN 55,212-2 (pIC50% in discs preincubated with [3H]NA, electrical stimulation: 7.03 and 6.70, respectively) but not affected by the inactive S(-)enantiomer of the latter, WIN 55,212-3 (up to 10 microM). The concentration-response curve of WIN 55,212-2 was shifted to the right by the CB1 receptor antagonist SR 141716 (apparent pA2: 8.29) which, by itself, increased the evoked overflow. The facilitatory effect of SR 141716 was not affected by GBR-12909 and the dopamine receptor antagonist haloperidol. In conclusion, the dopaminergic neurones of the guinea-pig retina can be labelled by both [3H]DA and [3H]NA. Transmitter release from the dopaminergic neurones is inhibited by activation of cannabinoid receptors of the CB1 type, which appear to be tonically activated by an endogenous CB receptor ligand.

Recombinant BCG expressing the leishmania surface antigen Gp63 induces protective immunity against Leishmania major infection in BALB/c mice

We have cloned and expressed the gp63 gene of Leishmania major in BCG to develop a recombinant vaccine against zoonotic cutaneous leishmaniasis. Two different expression systems were investigated. The first system consists of pAN, a Mycobacterium paratuberculosis promoter, which drives expression of ORF2, an open reading frame in IS900. This system allows the production of heterologous polypeptides as hybrids with the ORF2 gene product. The second expression system relies on the production of antigenic fragments as fusion proteins with the N-terminal region of Mycobacterium fortuitum beta-lactamase. Both constructs resulted in the production of Gp63 in BCG. The ability of the two recombinant BCG strains to induce protective immunity against a challenge with L. major amastigotes was evaluated after vaccination of susceptible (BALB/c), and resistant (C57BL/6) mice. Recombinant BCG producing Gp63 as a hybrid protein with the N-terminal region of the beta-lactamase elicited significant protection against a challenge with L. major in BALB/c-immunized mice.

Identification of mycobacterium tuberculosis DNA sequences encoding exported proteins by using phoA gene fusions

The activity of bacterial alkaline phosphatase (PhoA) is dependent on it being exported across the plasma membrane. A plasmid vector (pJEM11) allowing fusions between phoA and genes encoding exported proteins was constructed to study protein export in mycobacteria. Introduction of the Mycobacterium fortuitum beta-lactamase gene (blaF*) into this vector led to the production in M. smegmatis of protein fusions with PhoA activity. A genomic library from M. tuberculosis was constructed in pJEM11 and screened in M. smegmatis for clones with PhoA activity. Sequences of the M. tuberculosis inserts directing the production of protein fusions in these PhoA-positive clones were determined. They include part of the already-known exported 19-kDa lipoprotein, a sequence with similarities to the exported 28-kDa antigen from M. leprae, a sequence encoding a protein sharing conserved amino acid motifs with stearoyl-acyl-carrier-protein desaturases, and unknown sequences. This approach thus appears to identify sequences directing protein export, and we expect that more extensive screening of such libraries will lead to a better understanding of protein export in M. tuberculosis.

Escherichia coli-mycobacteria shuttle vectors for operon and gene fusions to lacZ: the pJEM series

A series of Escherichia coli-mycobacteria shuttle plasmids for the isolation and study of gene regulatory sequences was constructed. These pJEM vectors contain an efficient transcription terminator and multiple cloning sites and allow either operon or gene fusions to lacZ. By constructing operon fusions with pJEM15, we assessed various previously characterized mycobacterial promoters in the fast-growing species Mycobacterium smegmatis and the slow-growing species M. bovis BCG. Our results suggest that M. smegmatis and M. bovis BCG RNA polymerases do not share the same specificity. To isolate new mycobacterial promoters, an M. tuberculosis DNA library was generated, using pJEM13, and screened in M. smegmatis. Several Lac+ clones were isolated, and the beta-galactosidase activity was measured.

Transcription and expression analysis, using lacZ and phoA gene fusions, of Mycobacterium fortuitum beta-lactamase genes cloned from a natural isolate and a high-level beta-lactamase producer

The gene encoding a class A beta-lactamase was cloned from a natural isolate of Mycobacterium fortuitum (blaF) and from a high-level amoxicillin-resistant mutant that produces large amounts of beta-lactamase (blaF*). The nucleotide sequences of the two genes differ at 11 positions, including two in the region upstream from the coding sequence. Gene fusions to Escherichia coli lacZ and transcription and expression analysis of the cloned genes in Mycobacterium smegmatis indicated that high-level production of the beta-lactamase in the mutant is mainly or wholly due to a single base pair difference in the promoter. These analyses also showed that transcription and translation start at the same position. A comparison of the amino acid sequence of BlaF, as predicted from the nucleotide sequence, with the determined N-terminal amino acid sequence indicated the presence of a typical signal peptide. The fusion of blaF (or blaF*) to the E. coli gene phoA resulted in the production of BlaF-PhoA hybrid proteins that had alkaline phosphatase activity. These results demonstrate that phoA can be used as a reporter gene for studying protein export in mycobacteria.

Expression of Escherichia coli beta-galactosidase in Mycobacterium bovis BCG using an expression system isolated from Mycobacterium paratuberculosis which induced humoral and cellular immune responses

A promoter sequence, PAN, was isolated from Mycobacterium paratuberculosis and characterized. This promoter lies adjacent to, and outside, the 3' end of an IS900 insertion element. IS900 contains an open reading frame, ORF2, on the complementary strand which codes for the putative transposase of this insertion sequence. A DNA fragment containing PAN and part of ORF2 was fused to the lacZ gene and inserted into the replicative shuttle vector pRR3. Mycobacterium smegmatis and Mycobacterium bovis BCG (BCG) transformed with this plasmid exhibited beta-galactosidase activity. However, lacZ was only expressed in Escherichia coli under the control of PAN, when ORF2 was deleted. Immunization of mice with the recombinant M. bovis BCG expressing lacZ resulted in the induction of a high humoral and cellular response directed against beta-galactosidase. The PAN-ORF2 expression system may prove to be particularly useful for cloning and expression of heterologous genes in the BCG vaccine strain.

Molecular cloning, characterization and purification of ornithine carbamoyltransferase from Mycobacterium bovis BCG

A genomic library of Mycobacterium bovis BCG has been constructed by cloning DNA partially digested with Sau3A into the Escherichia coli expression vector pAS1. The gene coding for ornithine carbamoyl-transferase (EC.2.1.3.3; OTCase), hereafter referred to as argF, was isolated from the library by complementation of a double argF-argI mutant of E. coli and its sequence was determined. The translation initiation codon used, GTG, was identified by comparing the amino acid sequence deduced from the gene with the N-terminal sequence of the corresponding purified protein. On this basis, the M. bovis BCG OTCase monomer consists of 307 amino acid residues and displays about 44% identity with other OTCases, the most closely related homologue being the anabolic enzyme of Pseudomonas aeruginosa. The native enzyme has an estimated molecular mass of 110 kDa, suggesting a trimeric structure as is the case for most of the anabolic OTCases known from various organisms.

Occupational and environmental hazards associated with lung cancer

In a hospital-based case-control study 194 lung cancer cases, 194 hospital controls, and 194 population controls were interviewed for their smoking, occupational, and residential history by trained interviewers, using a standardized questionnaire. In order to include many different environmental exposures, case ascertainment took place in seven different hospitals with catchment areas ranging from rural to highly industrialized. Lung cancer risk strongly increases with cumulative cigarette dose, reaching an odds ratio (OR) of 16.19 (95% confidence limits (CL): 5.10, 51.33) for male smokers of more than 40 pack-years and an OR of 19.99 (95% CL: 4.98, 80.24) for female smokers of more than 20 pack-years. For the quantification of occupational exposure to known carcinogens of the lung a novel approach was developed which accumulates exposure information obtained by supplemental questionnaires through an automatic procedure. The OR for the highest exposure group in males was 2.7 (95% CL: 1.23, 5.78). Significantly increased risks were observed in the metal industry, particularly in smelter and foundry workers (OR 4.8, 95% CL: 1.15, 20.16) and in turners (OR 2.2, 95% CL: 1.05, 4.75). In the construction industry the risks were particularly high in road construction workers (OR 3.7, 95% CL: 1.06, 13.20) and in unskilled construction workers (OR 2.7, 95% CL: 1.24, 5.76). The risks in these occupational groups increased with duration and with latency. Quantification of air pollution was done on a county basis by time period. An index based on emission data for sulphur dioxide was compared to a semiquantitative index, which included additional information on ambient air pollution. After adjustment for smoking and occupational exposures an OR of 1.01 (95% CL: 0.53, 1.91) for an emission index and of 1.16 (95% CL: 0.64, 2.13) for a semiquantitative index was obtained.

Expression of heterologous genes in Mycobacterium bovis BCG: induction of a cellular response against HIV-1 Nef protein

Mycobacterium bovis bacillus Calmette-Guérin (BCG) has been used as a live bacterial vaccine to immunize more than two billion people against tuberculosis. In an attempt to use this vaccinal strain as a vehicle for protective antigens, the human immunodeficiency virus type 1 gene encoding the Nef protein was cloned in a mycobacteria-Escherichia coli shuttle plasmid and transferred into BCG. The nef gene was expressed under the control of an expression cassette carrying the promoter of the groES/groEL1 operon from Streptomyces albus and a synthetic ribosome-binding site. Lymph node cells from mice immunized with BCG-nef proliferated vigorously in response to purified Nef protein. This first report of a proliferative response suggests that recombinant BCG strains may be used to immunize against pathogens for which T-cell-mediated responses are important for protection.

Smoking cessation and nonsmoking intervals: effect of different smoking patterns on lung cancer risk

A case-control study of lung cancer was conducted in northwestern Germany in 1985-86. The study included 194 lung cancer cases and the same number of hospital controls and population controls who were matched to the cases by sex and age. Personal interviews were conducted by trained interviewers. We report here the effect of different smoking patterns--such as nonsmoking intervals, and time since quitting smoking--on lung cancer risk. Both quitting smoking and having a nonsmoking interval are seen to reduce lung cancer risk significantly. For a nonsmoking interval of three years or more, relative risk (RR) = 0.21, 95 percent confidence interval (CI) = 0.08-0.52; for quitting smoking for 10 years or more, RR = 0.23, CI = 0.11-0.48). A dose-response relationship was estimated for cigarette dose, length of nonsmoking interval, and time since stopped smoking.

The design of case-control studies: the effect of confounding on sample size requirements

This paper considers the extent to which confounding effects of covariates, which are not controlled for by matching in the design, may influence the sample size necessary for case-control studies. The quantitative calculations are performed for an age-matched case-control study on lung cancer and air pollution, and are based on different evaluation methods. For illustrative purposes attention is confined to a dichotomous risk factor and a single dichotomous covariate. By using the numerical values of a pilot study investigating lung cancer and air pollution, it turns out that the sample size required for detecting a relative risk as close as 1.15 to 1 is only slightly influenced by the strength of the association between confounder and risk factor for reasonable variations around our empirical values. On the other hand, sample size considerably increases with increasing relative risk of a confounder even when the association remains small. The sample size required for an individually matched analysis practically equals that for an age-stratified analysis when the relative risk of the covariate is one. With a relative risk greater than one, however, the size for a matched analysis exceeds that for a stratified analysis and the ratio between them increases with increasing relative risk.

Transposition of an antibiotic resistance element in mycobacteria

Bacterial resistance to antibiotics is often plasmid-mediated and the associated resistance genes encoded by transposable elements. Mycobacteria, including the human pathogens Mycobacterium tuberculosis and M. leprae, are resistant to many antibiotics, and their cell-surface structure is believed to be largely responsible for the wide range of resistance phenotypes. Antibiotic-resistance plasmids have so far not been implicated in resistance of mycobacteria to antibiotics. Nevertheless, antibiotic-modifying activities such as aminoglycoside acetyltransferases and phosphotransferases have been detected in fast-growing species. beta-lactamases have also been found in most fast- and slow-growing mycobacteria. To date no mycobacterial antibiotic-resistance genes have been isolated and characterized. We now report the isolation, cloning and sequencing of a genetic region responsible for resistance to sulphonamides in M. fortuitum. This region also contains an open reading frame homologous to one present in Tn1696 (member of the Tn21 family) which encodes a site-specific integrase. The mycobacterial resistance element is flanked by repeated sequences of 880 base pairs similar to the insertion elements of the IS6 family found in Gram+ and Gram- bacteria. The insertion element is shown to transpose to different sites in the chromosome of a related fast-growing species, M. smegmatis. The characterization of this element should permit transposon mutagenesis in the analysis of mycobacterial virulence and related problems.