The three‐year incidence of pulmonary arterial hypertension associated with systemic sclerosis in a multicenter nationwide longitudinal study in France

Objective

An algorithm for the detection of pulmonary arterial hypertension (PAH), based on the presence of dyspnea and the findings of Doppler echocardiographic evaluation of the velocity of tricuspid regurgitation (VTR) and right‐sided heart catheterization (RHC), which was applied in a large multicenter systemic sclerosis (SSc) population, estimated the prevalence of PAH to be 7.85%. The aim of this observational study was to investigate the incidence of PAH and pulmonary hypertension (PH) during a 3‐year followup of patients from the same cohort (the ItinérAIR‐Sclérodermie Study).

Methods

Patients with SSc and without evidence of PAH underwent evaluation for dyspnea and VTR at study entry and during subsequent visits. Patients in whom PAH was suspected because of a VTR of 2.8–3.0 meters/second and unexplained dyspnea or a VTR of >3.0 meters/second underwent RHC to confirm the diagnosis.

Results

A total of 384 patients were followed up for a mean ± SD of 41.03 ± 5.66 months (median 40.92 months). At baseline, 86.7% of the patients were women, and the mean ± SD age of the patients was 53.1 ± 12.0 years. The mean ± SD duration of SSc at study entry was 8.7 ± 7.6 years. After RHC, PAH was diagnosed in 8 patients, postcapillary PH in 8 patients, and PH associated with severe pulmonary fibrosis in 2 patients. The incidence of PAH was estimated to be 0.61 cases per 100 patient‐years. Two patients who exhibited a mean pulmonary artery pressure of 20–25 mm Hg at baseline subsequently developed PAH.

Conclusion

The estimated incidence of PAH among patients with SSc was 0.61 cases per 100 patient‐years. The high incidence of postcapillary PH highlights the value of RHC in investigating suspected PAH.

     

Targeting the polyamine transport system with benzazepine- and azepine-polyamine conjugates

The polyamine transport system (PTS) whose activity is up-regulated in cancer cells is an attractive target for drug design. Two heterocyclic (azepine and benzazepine) systems were conjugated to various polyamine moieties through an amidine bound to afford 18 compounds which were evaluated for their affinity for the PTS and their ability to use the PTS for cell delivery. Structure-activity relationship studies and lead optimization afforded two attractive PTS targeting compounds. The azepine-spermidine conjugate 14 is a very selective substrate of the PTS that may serve as a vector for radioelements used for diagnoses or therapeutics in nuclear medicine. The nitrobenzazepine-spermine conjugate 28 is a very powerful PTS inhibitor with very low intrinsic cytotoxicity, able to prevent the growth of polyamine depleted cells in presence of exogenous polyamines.     

Backward masking during rapid serial visual presentation affects the amplitude but not the latency of the P3 event‐related potential

Masking of the first target in the attentional blink (AB) paradigm increases the magnitude of the AB relative to when the first target is not masked. We examined the underlying causes of this effect in an experiment in which a single target was presented in a rapid visual serial presentation stream. The P3 to the target was isolated by subtracting infrequent target category trials from frequent target category trials. The item immediately trailing the target (i.e., the mask) was present in the masked condition and replaced by a blank screen in the not‐masked condition, reproducing conditions known to modulate the AB. Masking the target significantly reduced the amplitude of the target‐locked P3 but had no effect on P3 latency. Results are discussed in relation to previous findings in the AB literature.     

pfmdr1 Amplification Associated with Clinical Resistance to Mefloquine in West Africa: Implications for Efficacy of Artemisinin Combination Therapies

We describe here a clinical failure in the treatment with mefloquine of acute falciparum malaria contracted in Africa and associated with in vitro mefloquine resistance and pfmdr1 copy number amplification. This case raises the question of the presence and the evolution of this genotype in Africa, which is also known to alter the susceptibility to artemisinin combination therapy (ACT).     

Determination of Genotypic Diversity of Mycobacterium avium Subspecies from Human and Animal Origins by Mycobacterial Interspersed Repetitive-Unit-Variable-Number Tandem-Repeat and IS1311 Restriction Fragment Length Polymorphism Typing Methods

Members of the Mycobacterium avium complex (MAC) are ubiquitous bacteria that can be found in water, food, and other environmental samples and are considered opportunistic pathogens for numerous animal species, mainly birds and pigs, as well as for humans. We have recently demonstrated the usefulness of a PCR-based mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing for the molecular characterization of M. avium subsp. paratuberculosis and M. avium strains exclusively isolated from AIDS patients. In the present study we extended our analysis, based on eight MIRU-VNTR markers, to a strain collection comprehensively comprising the other M. avium subspecies, including M. avium subsp. avium, M. avium subsp. hominissuis, and M. avium subsp. silvaticum, isolated from numerous animal species, HIV-positive and HIV-negative humans, and environmental sources. All strains were fully typeable, with the discriminatory index being 0.885, which is almost equal to that obtained by IS1311 restriction fragment length polymorphism (RFLP) typing as a reference. In contrast to IS1311 RFLP typing, MIRU-VNTR typing was able to further discriminate M. avium subsp. avium strains. MIRU-VNTR alleles strongly associated with or specific for M. avium subspecies were detected in several markers. Moreover, the MIRU-VNTR typing-based results were consistent with a scenario of the independent evolution of M. avium subsp. avium/M. avium subsp. silvaticum and M. avium subsp. paratuberculosis from M. avium subsp. hominissuis, previously proposed on the basis of multilocus sequence analysis. MIRU-VNTR typing therefore appears to be a convenient typing method capable of distinguishing the three main subspecies and strains of the complex and providing new epidemiological knowledge on MAC.The most frequent agents of nontuberculous mycobacterioses belong to the Mycobacterium avium complex (MAC); in particular, M. avium subsp. hominissuis is a frequent agent of human mycobacterioses (12, 25). Members of this subspecies are also frequent infectious agents for pigs, leading to significant economic losses in pig farming, albeit that subspecies produces very low rates of morbidity in this animal species (23, 24). Two other MAC members, M. avium subsp. avium and M. avium subsp. paratuberculosis, are the causative agents of two other important, often fatal (2) animal pathologies, avian tuberculosis (40) and ruminant paratuberculosis (Johne''s disease) (6), respectively. Like other opportunistic agents, M. avium subsp. avium and M. avium subsp. hominissuis are also capable of infecting a wide range of animal species, including cattle, deer, wild boars, goats, and horses (40). In contrast, M. avium subsp. silvaticum is taxonomically very close to M. avium subsp. avium but almost exclusively infects wood pigeons (41).In the particular case of M. avium subsp. hominissuis, strains with similar or identical genotypes are usually found in common between pigs and human patients (26), which does not permit the potential zoonotic risk of this subspecies to be discarded. Moreover, these mycobacteria can be found in environmental sources such as water, biofilms, soil, aerosols, and phagocytic protozoa and amoebae (11), all of which can act as common sources of infection for animals and humans.For epidemiological investigations of MAC, the current reference molecular typing technique is restriction fragment length polymorphism analysis (RFLP) based on the IS1245 (47) and IS1311 (19, 20) insertion sequences. Whereas IS1311 RFLP usually generates clear hybridization patterns, IS1245 RFLP yields complex multiband patterns which are difficult to compare among different experiments and laboratories, mainly because of the heterogeneity in the intensities of the hybridization bands (19, 20, 42). Recently, an even simpler PCR-based molecular typing method, multilocus variable-number tandem-repeat analysis (MLVA), which is based on mycobacterial repetitive elements called mycobacterial interspersed repetitive-unit-variable-number tandem repeats (MIRU-VNTRs) (14, 34, 36, 37), has been described for M. avium subsp. paratuberculosis (38). This method presented better results for the differentiation of strains of this subspecies than those obtained by the standard IS900 RFLP method (38) and showed a promisingly good discrimination index (DI) with a panel of M. avium strains isolated from human AIDS patients (38).In the study described here, we extended that initial study by applying MIRU-VNTR typing to a large strain panel set comprising M. avium subsp. hominissuis, M. avium subsp. avium, and M. avium subsp. silvaticum strains isolated from diverse animal and human sources. Our aim was to further analyze the power of MIRU-VNTR typing to discriminate isolates within these subspecies and to identify possible specific signatures within the complex for better characterization and detection of interspecies transmission patterns.     

Identification of lumbar spinal neurons controlling simultaneously the prostate and the bulbospongiosus muscles in the rat

Lumbar spinothalamic neurons in the lamina X of the L3-L4 spinal cord segment have been proposed to constitute the spinal ejaculation generator in male rats. Lumbar spinothalamic cells are immunoreactive for galanin and neurokinin-1 receptors. We previously showed that after injection of pseudorabies virus either in the bulbospongiosus muscle or in the prostate, retrogradely labeled cells in the L3-L4 segment also displayed galanin or neurokinin-1 receptor immunoreactivities, demonstrating a direct link between lumbar spinothalamic cells and two anatomical structures involved in the two phases of ejaculation i.e. the emission and the expulsion phases. In order to provide with a more precise anatomical support for the role of lumbar spinothalamic cells in controlling ejaculation, we injected simultaneously in male adult rats two strains of recombinant pseudorabies virus, expressing either beta-galactosidase (PRV-BaBlu) or green fluorescent protein (PRV-152) in the prostate and in the bulbospongiosus muscle, respectively. After 5 days, we performed multiple immunofluorescence experiments to detect PRV-BaBlu, PRV-152 and galanin or neurokinin-1 receptors in transverse sections of the L1-S1 segment. Double- and triple-labeled cells were counted using confocal laser scanning microscope. Double-labeled neurons with the two strains of pseudorabies virus were mainly found at the L3-L4 segment lateral to the central canal in lamina X and represented about 60% of the total number of pseudorabies virus-labeled neurons. All the double pseudorabies virus-labeled neurons also expressed lumbar spinothalamic and most of them neurokinin-1 receptor, identifying them as lumbar spinothalamic neurons. The convergence of retrograde labeling from prostate and bulbospongiosus muscle on the same lumbar spinothalamic cells strongly reinforce their role in the spinal control and coordination of the emission and expulsion of sperm.