Image-based dynamic phenotyping reveals genetic determinants of filamentation-mediated beta-lactam tolerance

Antibiotic tolerance characterized by slow killing of bacteria in response to a drug can lead to treatment failure and promote the emergence of resistance. beta-lactam antibiotics inhibit cell wall growth in bacteria and many of them cause filamentation followed by cell lysis. Hence delayed cell lysis can lead to beta-lactam tolerance. Systematic discovery of genetic factors that affect beta-lactam killing kinetics has not been performed before due to challenges in high-throughput, dynamic analysis of viability of filamented cells during bactericidal action. We implemented a high-throughput time-resolved microscopy approach in a gene deletion library of Escherichia coli to monitor the response of mutants to the beta-lactam cephalexin. Changes in frequency of lysed and intact cells due to the antibiotic action uncovered several strains with atypical lysis kinetics. Filamentation confers tolerance because antibiotic removal before lysis leads to recovery through numerous concurrent divisions of filamented cells. Filamentation-mediated tolerance was not associated with resistance, and therefore this phenotype is not discernible through most antibiotic susceptibility methods. We find that deletion of Tol-Pal proteins TolQ, TolR, or Pal but not TolA, TolB, or CpoB leads to rapid killing by beta-lactams. We also show that the timing of cell wall degradation determines the lysis and killing kinetics after beta-lactam treatment. Altogether, this study uncovers numerous genetic determinants of hitherto unappreciated filamentation-mediated beta-lactam tolerance and support the growing call for considering antibiotic tolerance in clinical evaluation of pathogens. More generally, the microscopy screening methodology described here can easily be adapted to study lysis in large numbers of strains

Accuracy of registration algorithms in subtraction CT of the lungs: A digital phantom study

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Growing bone cysts in long-term hemodialysis

All patients with chronic renal failure undergoing hemodialysis for more than 10 years in the university hospitals of Leuven were selected for this study. The medical records and radiographs of these 21 patients were studied retrospectively. Skeletal surveys were examined for the presence and location of subchondral cysts. The predialysis films and the films taken after 5, 10, 15 and 20 years of dialysis were reviewed. Subchondral cysts that grew in size and number were found in the wrist, humeral head, hip, and patella. Accurate measurements were made of cysts in the wrist and compared with a control group. In the dialysis group, cystic involvement of the wrist was more common and the size and number of the cysts were larger. Soft tissue swelling was seen in the dialysis group but not in controls. Soft tissue swelling was assessed on shoulder radiographs by measuring the acromiohumeral distance (ACD) and in the knees by ultrasonic measurement of synovial thickness [25]. In 11 patients synovial or bone biopsies or aspirated synovial fluid were available. All these patients had swollen joints and multiple subchondral periarticular cysts. Amyloid deposition was found in ten of these patients, and this proved to be composed of B2 microglobulins in seven (Table 1).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46797/1/256_2004_Article_BF00197929.pd

Test-retest reliability of the ABILHAND Questionnaire in persons with chronic stroke.

To be able to evaluate recovery, effects of rehabilitation interventions and changes over time, reliable and valid outcome measures are needed. The ABILHAND Questionnaire is a measure of self-reported ability to perform complex daily hand activities. It is commonly used in stroke rehabilitation, but data about the measurement variability are missing

Interferon alfa for chronic hepatitis B infection: Increased efficacy of prolonged treatment

Interferon alfa (IFN-a) is the primary treatment for chronic hepatitis B. The standard duration of IFN-a therapy is considered 16 weeks; however, the optimal treatment length is still poorly defined. We evaluated the efficacy and acceptability of prolonged IFN-a treatment in patients with chronic hepatitis B. To investigate whether treatment prolongation could enhance the rate of hepatitis B e antigen (HBeAg) seroconversion, we conducted a prospective, controlled, multicenter trial in wh

Retreatment of hepatitis C non-responsive to Interferon. A placebo controlled randomized trial of Ribavirin monotherapy versus combination therapy with Ribavirin and Interferon in 121 patients in the Benelux [ISRCTN53821378]

BACKGROUND: Evidence based medicine depends on unbiased selection of completed randomized controlled trials. For completeness it is important to publish all trials. This report describes the first large randomised controlled trial where combination therapy was compared to placebo therapy and to ribavirin monotherapy, which has not been published untill now. METHODS: One hundred and twenty one patients with chronic hepatitis C and elevated transaminases who did not respond to previous treatment with standard interferon monotherapy, were included from 16 centers in Belgium, the Netherlands and Luxembourg between 1992 and 1996. Patient poor-response characteristics were: genotype 1 (69%), HCV RNA above 2 × 10(6 )copies/ml (55%) and cirrhosis (38%). Patients were randomized to 6 months combination therapy with interferon alpha-2b (3 MU tiw) and ribavirin (1000–1200 mg / day), 6 months ribavirin monotherapy (1000–1200 mg / day) or 6 months ribavirin placebo. The study was double blinded for the ribavirin / placebo component. One patient did not fit the entry criteria, and 3 did not start. All 117 patients who received at least one dose of treatment were included in the intention to treat analysis. RESULTS: At the end of treatment, HCV RNA was undetectable in 35% of patients on combination therapy and in none of the patients treated with ribavirin monotherapy or placebo. The sustained virological response rate at 6 months after therapy was 15% for patients treated with interferon and ribavirin. During the 6 months treatment period 13% of patients on interferon ribavirin combination therapy, 13% of patients on ribavirin monotherapy and 11% of patients on placebo withdrew due to side effects or noncompliance. At 24 weeks of treatment the mean Hb level was 85% of the baseline value, which means a mean decrease from 9.1 mmol/l to 7.8 mmol/l. The Hb levels at the end of treatment were not significantly different from patients treated with ribavirin monotherapy (p = 0.76). End of treatment WBC was significantly lower in patients treated with combination therapy, compared to ribavirin (p < 0.01) as well as for patients treated with ribavirin monotherapy compared to placebo (p < 0.01). DISCUSSION: This belated report on the only placebo controlled study of interferon ribavirin combination therapy in non responders to standard doses of interferon monotherapy documents the effectiveness, be it limited, of this approach as well as the dynamics of the effects on blood counts

The impact of a cancer Survivorship Care Plan on gynecological cancer patient and health care provider reported outcomes (ROGY Care): study protocol for a pragmatic cluster randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>There is a need for improvement of information provision and post-treatment care for cancer survivors. A Survivorship Care Plan (SCP) is recommended by the American Institute of Medicine and the Dutch Health Council, which is a summary of patients' course of treatment as a formal document, and includes recommendations for subsequent cancer surveillance, management of late effects, and strategies for health promotion. Until now, evidence on the effects of implementing the SCP in clinical practice is lacking. The rationale and study design of a pragmatic cluster randomized trial, aiming to assess the impact of SCP care in routine clinical practice, is presented.</p> <p>Methods/Design</p> <p>A web-based patient registration system 'Registrationsystem Oncological GYnecology' (ROGY) is used by gynecologists in the South of the Netherlands since 2006. A personalized SCP can automatically be generated out of ROGY. In this pragmatic cluster randomized controlled trial, 12 hospitals are randomized to either 'usual care' or 'SCP care'. In patients with 'usual care', the gynecologist provides care as usual. In patients with 'SCP care', information about the tumor stage and treatment is personally discussed with the patient and a document is handed to the patient. Prospectively, all patients diagnosed with endometrial or ovarian cancer in the participating hospitals will be approached for study participation. Patients will complete questionnaires after surgery, and before additional treatment, and after 6, 12, 18 and 24 months. In addition, health care providers will be asked their opinion about implementation of SCP care. Primary outcome is defined as patient satisfaction with information provision and care. Secondary outcomes are illness perception, health-related quality of life, health care use, prevalence, course and referral rate of survivors with psychosocial distress, and health care providers' evaluation of SCP care.</p> <p>Discussion</p> <p>The ROGY Care trial will help to gain insight into the impact of SCP care on patient reported outcomes, and on the evaluation of cancer survivors and health care providers of the different elements of the SCP. Therefore, results will contribute to efforts to improve quality of care for cancer survivors.</p> <p>Trial registration</p> <p>Trial Registration: <url>http://www.ClinicalTrials.gov</url>. Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01185626">NCT01185626</a></p> <p>Medical Research Ethics Committee Reference Number: NL33429.008.10 Grant Reference Number: UVT2010-4743</p