Structure-activity relationships in platelet-activating factor. Part 13: synthesis and biological evaluation of piperazine derivatives with dual anti-PAF and anti-HIV-1 or pure antiretroviral activity

HIV-1 infection of the brain and PAF neurotoxicity are implicated in AIDS dementia complex. We previously reported that a trisubstituted piperazine derivative is able to diminish both HIV-1 replication in monocyte-derived macrophages and PAF-induced platelet aggregation. We report in this work new compounds obtained by modifying its piperazine substituents. The structure-activity relationship study shows that a better dual activity or even pure antiretroviral compounds can be obtained in this series.     

Aluminum affects glial system and behavior of rats

Aluminum (Al) has been associated with neuronal dysfunction. These neuronal changes may involve glial alterations. We intend to evaluate the consequence of Al on the glial system and the behavior of rats exposed chronically to 0.3% of aluminum chloride in drinking water during 4 months in adulthood (A) or since intra-uterine age (IU); animals from this latter group were sacrificed at four months of age. Our data show an intense glial fibrillary acidic protein (GFAP)-immunoreactivity with a high density of astrocytes in both treated groups compared with controls. However, in IU rats, astrocytes display prominent glial cell bodies and processes. A and IU rat groups perform a significantly reduced locomotor activity. However, using the dark/light box test, the IU rats prefer to spend more time in the enlightened compartment compared to other groups. Behavioral and glial changes caused by Al exposure bring support for the role of Al in brain dysfunction involving glial alterations.     

The Association of IL-6, TNFα and CRP Gene Polymorphisms with Coronary Artery Disease in a Tunisian Population: A Case–Control study

Coronary artery disease is an inflammatory disease. Systemic markers of inflammation such as Interleukin-6, Tumor Necrosis Factor alpha and C-reactive protein have previously been shown to be associated with increased risk of cardiovascular events. The aim of the present study is to assess the role of variants in the IL-6 (??174 G/C), TNFα (??308 A/G) and CRP (+?1059G/C) genes as susceptibility markers for CAD in a Tunisian population. The investigation was conducted as a case–control study involving 204 patients and 400 age-gender matched controls. Genotyping was performed using polymerase chain reaction and restriction fragment length polymorphism analysis. There are significant differences between CAD patients and the control group with regard to BMI (p?<?10^–3) and family history of CAD (p?<?10^–3). The CAD patients are more likely to have a history of smoking (p?<?10^–3), have a higher value of TC (p?=?0.003), LDLc (p?=?0.016), hs-CRP (p?=?0.01), IL6 (p?<?10^–3) and TNFα (p?=?0.038). Our analysis showed significant differences between cases and controls in genotypic distribution of IL6-174CC (p?=?0.003; OR?=?7.71 CI (1.58–37.56)), TNFα ??308 AA (p?=?0.004; OR?=?2.95 (1.57–5.51)) and CRP?+?1059 CC (p?<?10^–3; OR?=?5.40 (2.30–12.68)). However, we failed to find an association between the different genotypes and the inflammatory markers levels. Our results suggest that the presence of IL-6 (??174 G/C), TNFα (-308 A/G) and CRP (+?1059G/C) polymorphisms, may be considered to be a risk factor for CAD in Tunisian population.

     

Paternal bisphenol A exposure induces testis and sperm pathologies in mice offspring: Possibly due to oxidative stress?

Bisphenol A (BPA), an endocrine and metabolic disruptor, is widely used to manufacture polycarbonate plastics and epoxy resins. Accumulating evidence suggests that paternal BPA exposure adversely affects male germlines and results in atypical reproductive phenotypes that might persist for generations to come. Our study investigated this exposure on testicular architecture and sperm quality in mouse offspring, and characterised underlying molecular mechanism(s). A total of 18 immature male Swiss albino mice (3.5 weeks old) were randomly divided into three groups and treated as follows: Group I, no treatment (sham control); Group II, sterile corn oil only (vehicle control); Group III, BPA (400 μg/kg) in sterile corn oil. At 9.5 weeks old, F0 males were mated with unexposed females. F0 offspring (F1 generation) were monitored for postnatal development for 10 weeks. At 11.5 weeks old, the animals were sacrificed to examine testicular architecture, sperm parameters, including DNA integrity, and oxidative stress biomarkers. Results showed that BPA significantly induced changes in the body and testis weights of the F0 and F1 generation BPA lineages compared to F0 and F1 generation control lineages. A decrease in sperm count and motility with further, increased sperm abnormalities, no or few sperm DNA alterations and elevated levels of MDA, PC and NO were recorded. Similar effects were found in BPA exposed F0 males, but were more pronounced in the F0 offspring. In addition, BPA caused alterations in the testicular architecture. These pathological changes extended transgenerationally to F1 generation males’ mice, but the pathological changes were more pronounced in the F1 generation. Our findings demonstrate that the biological and health BPA impacts do not end in paternal adults, but are passed on to offspring generations. Hence, linking observed testis and sperm abnormalities in the F1 generation to BPA exposure of their parental line was evident in this work. The findings also illustrate that oxidative stress appears to be a molecular component of the testis and sperm pathologies.     

Ovariectomized OVA-Sensitized Mice Display Increased Frequency of CD4+Foxp3+ T Regulatory Cells in the Periphery

It is well established that female sex hormones have a pivotal role in inflammation. For instance, our group has previously reported that estradiol has proinflammatory actions during allergic lung response in animal models. Based on these findings, we have decided to further investigate whether T regulatory cells are affected by female sex hormones absence after ovariectomy. We evaluated by flow cytometry the frequencies of CD4⁺Foxp3⁺ T regulatory cells (Tregs) in central and peripheral lymphoid organs, such as the thymus, spleen and lymph nodes. Moreover, we have also used the murine model of allergic lung inflammation a to evaluate how female sex hormones would affect the immune response in vivo. To address that, ovariectomized or sham operated female Balb/c mice were sensitized or not with ovalbumin 7 and 14 days later and subsequently challenged twice by aerosolized ovalbumin on day 21. Besides the frequency of CD4⁺Foxp3⁺ T regulatory cells, we also measured the cytokines IL-4, IL-5, IL-10, IL-13 and IL-17 in the bronchoalveolar lavage from lungs of ovalbumine challenged groups. Our results demonstrate that the absence of female sex hormones after ovariectomy is able to increase the frequency of Tregs in the periphery. As we did not observe differences in the thymus-derived natural occurring Tregs, our data may indicate expansion or conversion of peripheral adaptive Tregs. In accordance with Treg suppressive activity, ovariectomized and ovalbumine-sensitized and challenged animals had significantly reduced lung inflammation. This was observed after cytokine analysis of lung explants showing significant reduction of pro-inflammatory cytokines, such as IL-4, IL-5, IL-13 and IL-17, associated to increased amount of IL-10. In summary, our data clearly demonstrates that OVA sensitization 7 days after ovariectomy culminates in reduced lung inflammation, which may be directly correlated with the expansion of Tregs in the periphery and further higher IL-10 secretion in the lungs.     

Seasonal Modulation of the 8‐and 24‐Hour Rhythms of Ondansetron Tolerance in Mice

Ondansetron (Zophren®) is a serotonin 5HT₃-receptor antagonist used primarily to control nausea and vomiting caused by cytotoxic chemo‐and radio‐therapy. Tolerance to this drug shows both 24 and 8 h periodicities. In this framework, this study aimed to determine whether these ondansetron tolerance rhythms are modulated by season. The chronotoxic effect of a fixed dose (3.5 mg/kg, i.p.) of the drug was investigated with reference to both time of the day and year dependencies. Season‐related studies were performed on 560 male Swiss mice, 10 to 12 wks old, synchronized with L:D=12:12 for three weeks. During a 1 yr span (2005), four 24 h studies were performed with a single dosing time at 1, 7, 13, and 19 hours after light onset (HALO), respectively. Tolerance was assessed daily during a 40‐day span after acute ondansetron treatment. Both χ² test and cosinor methods were used to analyze the time series data. Statistically significant dosing time‐dependent changes were validated in both yearly and daily time scales. The 24 h mean survival rate peaked in spring (92%) compared to fall (72%), the 20% difference being statistically significant (χ² test with p<0.05 and cosinor with p<0.0001 for seasonal rhythm detection and with a peak time, Ø,=April 3±6.6 days). A 24 h rhythm was also detected in each of the seasonal time points. However, the curve pattern was monophasic in fall as well as spring. In fall, a large amplitude (A) circadian rhythm was detected that peaked at 19 HALO, while in the spring, a small circadian rhythm was detected that peaked at 1 HALO. The curve pattern was biphasic in summer (with large A) and in winter (with a small A). The existence of two peaks of equal magnitude in winter (100% survival rate) and in summer (100% and 90%) suggests the presence of both circadian and ultradian rhythms rather than an ultradian component of the 24 h period. The seasonal modulation of ondansetron circadian chronotolerance seems to involve several rhythm parameters: season‐related changes in the 24 h mean (M), amplitude (A), acrophase location (Ø), as well as bimodal curve patterns including the coexistence of rhythms with respectively 24 and 8 h periods in winter and summer. In conclusion, tolerance to ondansetron varies not only according to the 24 and 8 h periods but also according to seasons, which suggests the complexity of ondansetron toxicity rhythms. Seasonal modulation of ondansetron tolerance may also influence the strategies of chemo‐and chrono‐therapy, and it is therefore necessary to take it into account in clinical drug‐delivery protocols to minimize side effects of cytotoxic anticancer and antiemetic agents.     

Analysis of humeral head displacements from sequences of biplanar X-rays: repeatability study and preliminary results in healthy subjects

This work presents an accurate method to measure gleno-humeral translations in a controlled pseudo-kinematic environment. Low-dose biplanar X-rays were acquired from nine healthy subjects at three elevations of the arm in the scapular plane. On each set of images, shoulder bony landmarks were manually located in 3D using a dedicated software. Intra-observer and inter-observer repeatability of landmark identification, as well as humeral head center (GH) translations, were studied. Repeatability for the identification of GH in the global coordinate system (CS) was good with 95% confidence intervals (CIs) ranging from 0.57 to 2.25 mm. Scapular landmark CIs ranged from 0.80 to 12 mm. Gleno-humeral translations of small amplitude ( < 6 mm) were detected in seven out of nine subjects. The results obtained here confirm that calibrated low-dose stereo-radiography is a promising tool for the functional analysis of the shoulder.     

3D Evaluation of the acetabular coverage assessed by biplanar X-rays or single anteroposterior X-ray compared with CT-scan

Considering the increasing development of three dimensional (3D) imaging, the 3D assessment of the acetabular coverage is to become the most interesting tool for the detection of acetabular pathologies. Biplanar X-rays based methods allow a 3D reconstruction of the hip with a reduced radiation dose. This study proposes a 3D assessment method of the acetabular coverage from biplanar X-rays or from an anteroposterior X-ray (conventional clinical imaging). An in vitro evaluation of the method was performed on six hip joints in comparison with computed tomography. The global coverage, the local coverage and the acetabular rim orientation were estimated in 3D. The mean global acetabular coverage was 40% with an estimated mean accuracy of 1.3% for the biplanar X-rays based method. This study evaluated a 3D assessment method of the acetabular coverage from biplanar X-rays or anteroposterior X-ray and open the way for clinical in vivo applications.     

Pathways of cryptic invasion in a fish parasite traced using coalescent analysis and epidemiological survey

Introduced species have the potential to outperform natives via the introduction of new parasites to which the native ecosystem is vulnerable. Cryptic diversity within an invasive species can obscure invasion patterns and confound proper management measures. The aim of this study is to use coalescent theory based methodology to trace recent routes of invasion in populations of Ligula intestinalis, a globally distributed fish parasite possessing both native and recently introduced populations in North Africa. Molecular analyses of mitochondrial DNA discerned a pronounced genetic divergence between introduced and native populations. Distribution of mitochondrial haplotypes demonstrated common origin of European populations with North African parasites sampled from introduced fish species in Tunisia. To test the suggested pathway of introduction, microsatellite data were examined in a model-based coalescent analysis using the software MIGRATE, where Europe to Tunisia direction of migration was favoured over alternative hypotheses of gene flow. Specificity of Tunisian populations to different host species was assessed in an epidemiologic survey confirming prevailing host-based division between introduced and native parasites in North Africa. This approach combining advanced analysis of molecular markers with host-specificity data allows revealing the evolution of host-parasite interactions following biological invasion and provides basis for devising future management measurements.