Distribution of atrial natriuretic peptide and its effects on contraction and intracellular calcium in ventricular myocytes from streptozotocin-induced diabetic rat

The distribution of atrial natriuretic peptide (ANP) in blood plasma and cardiac muscle and its effects on ventricular myocyte contraction and intracellular free calcium concentration [Ca2+]i in the streptozotocin (STZ)-induced diabetic rat have been investigated. Blood plasma concentration and heart atrial and ventricular contents of ANP were significantly increased in STZ-treated rats compared to age-matched controls. STZ treatment increased the number of ventricular myocytes immunolabeled with antibodies against ANP. In control myocytes the percentage of cells that labeled positively and negatively were 17% versus 83%, respectively. However, in myocytes from STZ-treated rat the percentages were 52% versus 53%. Time to peak (TPK) shortening was significantly and characteristically prolonged in myocytes from STZ-treated rats (360+/-5 ms) compared to controls (305+/-5 ms). Amplitude of the Ca2+ transient was significantly increased in myocytes from STZ-treated rats compared to controls (0.39+/-0.02 versus 0.29+/-0.02 fura-2 RU in controls) and treatment with ANP reduced the amplitude of the Ca2+ transient to control levels. ANP may have a protective role in STZ-induced diabetic rat heart.     

Targeting human langerin promotes HIV-1 specific humoral immune responses

The main avenue for the development of an HIV-1 vaccine remains the induction of protective antibodies. A rationale approach is to target antigen to specific receptors on dendritic cells (DC) via fused monoclonal antibodies (mAb). In mouse and non-human primate models, targeting of skin Langerhans cells (LC) with anti-Langerin mAbs fused with HIV-1 Gag antigen drives antigen-specific humoral responses. The development of these immunization strategies in humans requires a better understanding of early immune events driven by human LC. We therefore produced anti-Langerin mAbs fused with the HIV-1 gp140z Envelope (αLC.Env). First, we show that primary skin human LC and in vitro differentiated LC induce differentiation and expansion of naïve CD4⁺ T cells into T follicular helper (Tfh) cells. Second, when human LC are pre-treated with αLC.Env, differentiated Tfh cells significantly promote the production of specific IgG by B cells. Strikingly, HIV-Env-specific Ig are secreted by HIV-specific memory B cells. Consistently, we found that receptors and cytokines involved in Tfh differentiation and B cell functions are upregulated by LC during their maturation and after targeting Langerin. Finally, we show that subcutaneous immunization of mice by αLC.Env induces germinal center (GC) reaction in draining lymph nodes with higher numbers of Tfh cells, Env-specific B cells, as well as specific IgG serum levels compared to mice immunized with the non-targeting Env antigen. Altogether, we provide evidence that human LC properly targeted may be licensed to efficiently induce Tfh cell and B cell responses in GC.     

Study of the Effect of Phosphorus on Mineral Nutrition of Faba Bean « Vicia fabae L.»

Our study focuses on the study of the phosphorus efficiency on the mineral nutrition of a leguminous plant; to study this efficiency, we tested the effect of increasing doses of phosphorus on the mineral nutrition of faba bean and on the concentration of Nt (total nitrogen), Pi (available phosphorus), KE (exchangeable potassium), C (organic carbon), and the organic matter (OM) rate in the rhizospheric soil after harvest, as well as the concentration of N, P, K, Na, and Ca in the roots, stems, leaves, and seeds of faba bean. The faba bean crop was subjected to four phosphorus doses (P0?=?0 kg/ha; P1?=?70 kg/ha; P2?=?140 kg/ha; P3?=?210 kg/ha). The main results obtained showed that the concentration of the mineral elements in the different faba bean parts reacted differently to the phosphorus treatments. Regarding the dosage of nutrients in the different parts of the faba bean, the results obtained highlight that Pi deficiency in the soil does not only affect phosphate nutrition but can also affect the absorption of other mineral elements, a synergy is recorded between the K concentration in the roots and in the stems with the organic carbon in the soil, and an antagonism between K and Na in the different parts of the plant. All the results obtained in this work show that a phosphate fertilization for doses between 70 kg/ha and 140 kg/ha of P2O5 improves the microbial life of soil microorganisms.

     

Combination Proximal Pulmonary Artery Coiling and Distal Embolization Induces Chronic Elevations in Pulmonary Artery Pressure in Swine

Pulmonary hypertension (PH) is associated with aberrant vascular remodeling and right ventricular (RV) dysfunction that contribute to early mortality. Large animal models that recapitulate human PH are essential for mechanistic studies and evaluating novel therapies; however, these models are not readily accessible to the field owing to the need for advanced surgical techniques or hypoxia. In this study, we present a novel swine model that develops cardiopulmonary hemodynamics and structural changes characteristic of chronic PH. This percutaneous model was created in swine (n=6) by combining distal embolization of dextran beads with selective coiling of the lobar pulmonary arteries (2 procedures per lung over 4 weeks). As controls, findings from this model were compared with those from a standard weekly distal embolization model (n=6) and sham animals (n=4). Survival with the combined embolization model was 100%. At 8 weeks after the index procedure, combined embolization procedure animals had increased mean pulmonary artery pressure (mPA) and pulmonary vascular resistance (PVR) compared to the controls with no effect on left heart or systemic pressures. RV remodeling and RV dysfunction were also present with a decrease in the RV ejection fraction, increase in the myocardial performance index, impaired longitudinal function, as well as cardiomyocyte hypertrophy, and interstitial fibrosis, which were not present in the controls. Pulmonary vascular remodeling occurred in both embolization models, although only the combination embolization model had a decrease in pulmonary capacitance. Taken together, these cardiopulmonary hemodynamic and structural findings identify the novel combination embolization swine model as a valuable tool for future studies of chronic PH.     

Diabetic retinopathy in the Eastern Morocco: Different stage frequencies and associated risk factors

Diabetes is a major cause of morbidity and mortality worldwide. It can affect many organs and, over time, leads to serious complications. Diabetic retinopathy (DR), a specific ocular complication of diabetes, remains the leading cause of vision loss and vision impairment in adults. This work is the first in Eastern Morocco aimed at identifying the different stages of DR and to determine their frequencies and associated risk factors. It is a case-control study conducted from December 2018 to July 2019 at the ophthalmology department of Al-Irfane Clinic (Oujda). Data were obtained from a specific questionnaire involving 244 diabetic patients (122 cases with retinopathy vs 122 controls without retinopathy). All results were analyzed by the EPI-Info software. This study shows a predominance of proliferative diabetic retinopathy (PDR) with 57.4% of cases (uncomplicated proliferative diabetic retinopathy (UPDR): 23.8%; complicated proliferative diabetic retinopathy (CPDR): 33.6%). The non-proliferative diabetic retinopathy (NPDR) represents 42.6% (minimal NPDR: 8.2%; moderate NPDR: 26.2%; severe NPDR: 8.2%). The determinants of DR were insulin therapy, high blood pressure, poor glycemic control and duration of diabetes. Regarding the chronological evolution, retinopathy precedes nephropathy. Diabetic nephropathy (DN) was present in 10.6% of cases especially in patients with PDR. In summary, the frequency of PDR was higher than that of NPDR. DR appears before DN with a high frequency of DN in patients with PDR. Good glycemic control and blood pressure control, as well as early diagnosis are the major preventive measures against DR.     

Antioxidant activity of benzoxazolinonic and benzothiazolinonic derivatives in the LDL oxidation model

A series of benzazolone compounds were synthesized utilizing benzoxazolinonic and benzothiazolinonic heterocycles as the building unit. The antioxidant activity of these compounds was determined by inhibition of lipid peroxidation. The oxidation of LDL was induced in the presence of CuSO₄ or 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH). The protective action of these compounds against the cytotoxicity was evaluated with lactate dehydrogenase (LDH) activity in bovine aortic endothelial cells (BAECs) and cellular vitality by measuring mitochondrial activity in the presence of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide). The best antioxidant activities were observed for phenolic compounds 13 and 14b with ratio R = 2.5, 3.2 (5 μM). Both of these test substances increased the cell viability significantly as indicated by MTT assay and LDH release assay.     

Type-2 histone deacetylases as new regulators of elicitor-induced cell death in plants

? Plant resistance to pathogen attack is often associated with a localized programmed cell death called hypersensitive response (HR). How this cell death is controlled remains largely unknown. ? Upon treatment with cryptogein, an elicitor of tobacco defence and cell death, we identified NtHD2a and NtHD2b, two redundant isoforms of type-2 nuclear histone deacetylases (HDACs). These HDACs are phosphorylated after a few minutes' treatment, and their rate of mRNAs are rapidly and strongly reduced, leading to a 40-fold decrease after 10 h of treatment. ? By using HDAC inhibitors, RNAi- and overexpression-based approaches, we showed that HDACs, and especially NtHD2a/b, act as inhibitors of cryptogein-induced cell death. Moreover, in NtHD2a/b-silenced plants, infiltration with cryptogein led to HR-like symptoms in distal leaves. ? Taken together, these results show for the first time that type-2 HDACs, which are specific to plants, act as negative regulators of elicitor-induced cell death in tobacco (Nicotiana tabacum), suggesting that the HR is controlled by post-translational modifications including (de)acetylation of nuclear proteins.