Screening of anti-mycobacterial compounds in a naturally infected zebrafish larvae model.

OBJECTIVES: Mycobacterium tuberculosis is a deadly human pathogen that causes the lung disease TB. M. tuberculosis latently infects a third of the world's population, resulting in ∼1.5 million deaths per year. Due to the difficulties and expense of carrying out animal drug trials using M. tuberculosis and rodents, infections of the zebrafish Danio rerio with Mycobacterium marinum have become a useful surrogate. However, the infection methods described to date require specialized equipment and a high level of operator expertise. METHODS: We investigated whether zebrafish larvae could be naturally infected with bioluminescently labelled M. marinum by immersion, and whether infected larvae could be used for rapid screening of anti-mycobacterial compounds using bioluminescence. We used rifampicin and a variety of nitroimidazole-based next-generation and experimental anti-mycobacterial drugs, selected for their wide range of potencies against M. tuberculosis, to validate this model for anti-mycobacterial drug discovery. RESULTS: We observed that five of the six treatments (rifampicin, pretomanid, delamanid, SN30488 and SN30527) significantly reduced the bioluminescent signal from M. marinum within naturally infected zebrafish larvae. Importantly, these same five treatments also retarded the growth of M. tuberculosis in vitro. In contrast, only three of the six treatments tested (rifampicin, delamanid and SN30527) retarded the growth of M. marinum in vitro. CONCLUSIONS: We have demonstrated that zebrafish larvae naturally infected with bioluminescent M. marinum M can be used for the rapid screening of anti-mycobacterial compounds with readily available equipment and limited expertise. The result is an assay that can be carried out by a wide variety of laboratories for minimal cost and without high levels of zebrafish expertise.

Implantable loop recorders: a viable diagnostic tool in veterinary medicine.

OBJECTIVE: The purpose of this study was to investigate whether implantable loop recorders could be used in the diagnosis of unexplained collapse in dogs. METHODS: The medical records of six dogs presented to the University of Liverpool Small Animal Teaching Hospital between May 2003 and October 2006 for further evaluation of intermittent syncopal episodes, collapse or episodic weakness, were reviewed. All these dogs underwent standard investigations and had implantable loop recorders placed. RESULTS: A provisional diagnosis of supraventricular tachycardia was made in one dog, and diagnoses of exclusion of arrhythmogenic right ventricular cardiomyopathy and idiopathic epilepsy was made in two dogs. One dog suffered no further syncopal episodes, a diagnosis was not reached in another dog and the final dog was lost to follow-up. CLINICAL SIGNIFICANCE: The implantable loop recorder can be used successfully for the diagnosis of unexplained collapse in dogs.

Strictures of the sigmoid colon: barium enema evaluation.

PURPOSE: To assess the accuracy of radiologic interpretation, in the absence of clinical information, in the differentiation of benign and malignant sigmoid strictures at barium enema examination. MATERIALS AND METHODS: On two occasions, four independent observers retrospectively assessed examination findings in 78 patients with documented sigmoid strictures (43 benign, 35 malignant). Each stricture was graded by using a five-point scale (definitely malignant to definitely benign). RESULTS: No significant difference existed between the areas under the receiver operating characteristic curves for the two assessments with any observer. Consensus findings indicated agreement among at least three of the four observers in 68 (87%) and 66 (85%) cases at the first and second assessments, respectively. One benign stricture was called malignant at both assessments. When consensus existed, the positive predictive value for malignant strictures was 96% at both assessments (sensitivity, 63% and 66%). Nine malignant strictures were called benign, three at both assessments. When consensus existed, the positive predictive value for benign strictures was 84% and 88% at the first and second assessments, respectively (sensitivity, 88% and 86%, respectively). CONCLUSION: The differentiation between a benign and a malignant sigmoid stricture can be made in most cases at barium enema examination. When a stricture appears malignant, the diagnosis is usually correct, but caution is advised when a stricture appears benign.

Pelvic floor electrical stimulation in the treatment of genuine stress incontinence: a multicenter, placebo-controlled trial.

OBJECTIVE: Our purpose was to determine the efficacy of transvaginal electrical stimulation in treating genuine stress incontinence. STUDY DESIGN: This was a multicenter, prospective, randomized, double-blind, placebo-controlled 15-week trial comparing the use of an active pelvic floor stimulator with a sham device. Thirty-five women used an active unit and 17 control subjects used sham devices. Weekly and daily voiding diaries were recorded throughout the trial. Urodynamic testing, including pad test and subtracted cystometry, was done before and at the end of device use. Pelvic muscle strength was measured at baseline and at the end of the trial. Patients scored their symptoms on visual analog scales and completed quality-of-life questionnaires before and after therapy. RESULTS: Significant improvements from baseline were found in patients using active devices but not in controls. Comparisons of changes from baseline between active-device and control patients showed that active-device patients had significantly greater improvement in weekly (p = 0.009) and daily (p = 0.04) leakage episodes, pad testing (p = 0.005), and vaginal muscle strength (p = 0.02) when compared with control subjects. Significantly greater improvement was also found for both visual analog scores of urinary incontinence (p = 0.007) and stress incontinence (p = 0.02), as well as for subjective reporting of frequency of urine loss (p = 0.002), and urine loss with sneezing, coughing, or laughing (p = 0.02), when compared with controls. Pad testing showed that stress incontinence was improved by at least 50% in 62% of patients using an active device compared with only 19% of patients using sham devices (p = 0.01). Voiding diaries showed at least 50% improvement in 48% of active-device patients compared with 13% of women using the sham device (p = 0.02). No irreversible adverse effects were noted in either group. CONCLUSIONS: Transvaginal pelvic floor electrical stimulation was found to be a safe and effective therapy for genuine stress incontinence.