Mycoplasma genitalium,an agent of reemerging sexually transmitted infections

M. genitalium is a reemerging microorganism, responsible for sexually transmissible infections (STIs), with prevalence which varies depending on the country and population group studied. We report here M. genitalium prevalence among the specimens received for STI diagnosis in our routine microbiological laboratory in the university hospital in Marseille, France. We tested 4 624 samples from 3 793 patients using qPCR for M. genitalium, C. trachomatis, N. gonorrheae, T. pallidum. Of these samples, 528 (13.6%) patients were tested positive for at least one pathogen and 126 (3.3%) were positive for M. genitalium. M. genitalium is the second most prevalent micro‐organism detected in women after C. trachomatis (10.4%) and the third most prevalent in men after C. trachomatis (5.1%) and N. gonorrhoeae (4.4%). We observed no significant differences between the prevalence of M. genitalium in vaginal, urethral and urine specimens (p = 0.9). Prevalence of M. genitalium is significantly higher in patients aged between 10–30 years (4.1%) compared to those aged between 30 and 50 years (2.7%) (p = 0.02, RR = 1.54 [1.06–2.24]) and patients over 50 years of age (1.1%) (p = 0.003, RR= 3.98 [1.47–10.8]). M. genitalium is a common agent of STI, therefore we suggest that this micro‐organism should be systematically tested during chronic, recurrent, or antibiotic resistant genital infections and in populations at high‐risk of STIs.     

Differential diagnosis of pulmonary embolism in outpatients with non-specific cardiopulmonary symptoms

Most cardiopulmonary diseases share at least one symptom with pulmonary embolism (PE). The aim of this study was to identify the most common acute causes of dyspnea, chest pain, fainting or palpitations, which diagnostic procedures were performed and whether clinicians investigate them appropriately. An Italian multicenter collaboration gathered 17,497 Emergency Department (ED) records of patients admitted from January 2007 to June 2007 in six hospitals. A block random sampling procedure was applied to select 800 hospitalised patients. Results of the overall 17,497 patients were obtained by weighting sampled cases according to the probability of the randomisation block variables in the whole population. The case-mix of enrolled patients was assessed in terms of cardiopulmonary symptoms, and the prevalence of acute disorders. The actual performance of procedures was compared with a measure of their accuracy as expected in the most common clinical presentations. PE occurred in less than 4% of patients with cardiopulmonary symptoms. Acute heart failure, pneumonia and chronic obstructive pulmonary disease exacerbation were the most likely diagnoses in patients with dyspnea. Acute myocardial infarction was present in roughly 10% of patients with chest pain. Atrial fibrillation was the prevalent diagnosis in patients with palpitations. Echocardiography, computed tomographic pulmonary angiography, perfusion lung scan, D-dimer test and B-type natriuretic peptide were performed less than expected from their accuracy. Diagnostic strategies, starting from non-specific symptoms and coping with the eventuality of PE, are likely to benefit from an increased awareness of the examination’s accuracy in discriminating among several competing hypotheses, rather than in testing the single PE suspicion.     

Visualizing novel concepts of cardiovascular calcification

Cardiovascular calcification is currently viewed as an active disease process similar to embryonic bone formation. Cardiovascular calcification mainly affects the aortic valve and arteries and is associated with increased mortality risk. Aortic valve and arterial calcification share similar risk factors, including age, gender, diabetes, chronic renal disease, and smoking. However, the exact cellular and molecular mechanism of cardiovascular calcification is unknown. Late-stage cardiovascular calcification can be visualized with conventional imaging modalities such as echocardiography and computed tomography. However, these modalities are limited in their ability to detect the development of early calcification and the progression of calcification until advanced tissue mineralization is apparent. Due to the subsequent late diagnosis of cardiovascular calcification, treatment is usually comprised of invasive interventions such as surgery. The need to understand the process of calcification is therefore warranted and requires new imaging modalities which are able to visualize early cardiovascular calcification. This review focuses on the use of new imaging techniques to visualize novel concepts of cardiovascular calcification.     

Starch digestibility modulation significantly improves glycemic variability in type 2 diabetic subjects: A pilot study

Background and aimsIn type 2 diabetes (T2D) patients, the reduction of glycemic variability and postprandial glucose excursions is essential to limit diabetes complications, beyond HbA1c level. This study aimed at determining whether increasing the content of Slowly Digestible Starch (SDS) in T2D patients’ diet could reduce postprandial hyperglycemia and glycemic variability compared with a conventional low-SDS diet.Methods and resultsFor this randomized cross-over pilot study, 8 subjects with T2D consumed a controlled diet for one week, containing starchy products high or low in SDS. Glycemic variability parameters were evaluated using a Continuous Glucose Monitoring System.Glycemic variability was significantly lower during High-SDS diet compared to Low-SDS diet for MAGE (Mean Amplitude of Glycemic Excursions, p < 0.01), SD (Standard Deviation, p < 0.05), and CV (Coefficient of Variation, p < 0.01). The TIR (Time In Range) [140–180 mg/dL[ was significantly higher during High-SDS diet (p < 0.0001) whereas TIRs ≥180 mg/dL were significantly lower during High-SDS diet. Post-meals tAUC (total Area Under the Curve) were significantly lower during High-SDS diet.ConclusionOne week of High-SDS Diet in T2D patients significantly improves glycemic variability and reduces postprandial glycemic excursions. Modulation of starch digestibility in the diet could be used as a simple nutritional tool in T2D patients to improve daily glycemic control.Registration numberin clinicaltrials.gov: NCT 03289494.     

Deletion of the Uracil Permease Gene Confers Cross-Resistance to 5-Fluorouracil and Azoles in Candida lusitaniae and Highlights Antagonistic Interaction between Fluorinated Nucleotides and Fluconazole

We characterized two additional membrane transporters (Fur4p and Dal4p) of the nucleobase cation symporter 1 (NCS1) family involved in the uptake transport of pyrimidines and related molecules in the opportunistic pathogenic yeast Candida lusitaniae. Simple and multiple null mutants were constructed by gene deletion and genetic crosses. The function of each transporter was characterized by supplementation experiments, and the kinetic parameters of the uptake transport of uracil were measured using radiolabeled substrate. Fur4p specifically transports uracil and 5-fluorouracil. Dal4p is very close to Fur4p and transports allantoin (glyoxyldiureide). Deletion of the FUR4 gene confers resistance to 5-fluorouracil as well as cross-resistance to triazoles and imidazole antifungals when they are used simultaneously with 5-fluorouracil. However, the nucleobase transporters are not involved in azole uptake. Only fluorinated pyrimidines, not pyrimidines themselves, are able to promote cross-resistance to azoles by both the salvage and the de novo pathway of pyrimidine synthesis. A reinterpretation of the data previously obtained led us to show that subinhibitory doses of 5-fluorocytosine, 5-fluorouracil, and 5-fluorouridine also were able to trigger resistance to fluconazole in susceptible wild-type strains of C. lusitaniae and of different Candida species. Our results suggest that intracellular fluorinated nucleotides play a key role in azole resistance, either by preventing azoles from targeting the lanosterol 14-alpha-demethylase or its catalytic site or by acting as a molecular switch for the triggering of efflux transport.     

Effect of a Radiotherapeutic Megavoltage Beam on Ultrasound Contrast Agents

Collateral damage to healthy surrounding tissue during conventional radiotherapy increases when deviations from the treatment plan occur. Ultrasound contrast agents (UCAs) are a possible candidate for radiation dose monitoring. This study investigated the size distribution and acoustic response of two commercial formulations, SonoVue/Lumason and Definity/Luminity, as a function of dose on clinical megavoltage photon beam exposure (24 Gy). SonoVue samples exhibited a decrease in concentration of bubbles smaller than 7 µm, together with an increase in acoustic attenuation and a decrease in acoustic scattering. Definity samples did not exhibit a significant response to radiation, suggesting that the effect of megavoltage photons depends on the UCA formulation. For SonoVue, the influence of the megavoltage photon beam was especially apparent at the second harmonic frequency, and can be captured using pulse inversion and amplitude modulation (3.5-dB decrease for the maximum dose), which could eventually be used for dosimetry in a well-controlled environment.