Role of MHC-linked genes in autoantigen selection and renal disease in a murine model of systemic lupus erythematosus

We previously described a renal protective effect of factor B deficiency in MRL/lpr mice. Factor B is in the MHC cluster; thus, the deficient mice were H2b, the haplotype on which the knockout was derived, whereas the wild-type littermates were H2k, the H2 of MRL/lpr mice. To determine which protective effects were due to H2 vs factor B deficiency, we derived H2b congenic MRL/lpr mice from the 129/Sv (H2b) strain. Autoantibody profiling using autoantigen microarrays revealed that serum anti-Smith and anti-small nuclear ribonucleoprotein complex autoantibodies, while present in the majority of H2k/k MRL/lpr mice, were absent in the H2b/b MRL/lpr mice. Surprisingly, 70% of MRL/lpr H2b/b mice were found to be serum IgG3 deficient (with few to no IgG3-producing B cells). In addition, H2b/b IgG3-deficient MRL/lpr mice had significantly less proteinuria, decreased glomerular immune complex deposition, and absence of glomerular subepithelial deposits compared with MRL/lpr mice of any H2 type with detectable serum IgG3. Despite these differences, total histopathologic renal scores and survival were similar among the groups. These results indicate that genes encoded within or closely linked to the MHC region regulate autoantigen selection and isotype switching to IgG3 but have minimal effect on end-organ damage or survival in MRL/lpr mice.     

Mesenchymal stem cell therapy: A promising cell‐based therapy for treatment of myocardial infarction

For decades, mesenchymal stem (MSCs) cells have been used for cardiovascular diseases as regenerative therapy. This review is an attempt to summarize the types of MSCs involved in myocardial infarction (MI) therapy, as well as its possible mechanisms effects, especially the paracrine one in MI focusing on the studies (human and animal) conducted within the last 10 years. Recently, reports showed that MSC therapy could have infarct‐limiting effects after MI in both experimental and clinical trials. In this context, various types of MSCs can help cardiac regeneration by either revitalizing the cardiac stem cells or revascularizing the arteries and veins of the heart. Furthermore, MSCs could produce paracrine growth factors that increase the survival of nearby cardiomyocytes, as well as increase angiogenesis through recruitment of stem cell from bone marrow or inducing vessel growth from existing capillaries. Recent research suggests that the paracrine effects of MSCs could be mediated by extracellular vesicles including exosomes. Exosomal microRNAs (miRNAs) released by MSCs are promising therapeutic hotspot target for MI. This could be attributed to the role of miRNA in cardiac biology, including cardiac regeneration, stem cell differentiation, apoptosis, neovascularization, cardiac contractility and cardiac remodeling. Furthermore, gene‐modified MSCs could be a recent promising therapy for MI to enhance the paracrine effects of MSCs, including better homing and effective cell targeted tissue regeneration. Although MSC therapy has achieved considerable attention and progress, there are critical challenges that remains to be overcome to achieve the most effective successful cell‐based therapy in MI.     

Steady‐state and synchronous spectrofluorimetric methods for simultaneous determination of aliskiren hemifumarate and amlodipine besylate in dosage forms

Aliskiren hemifumarate (ALS) and amlodipine besylate (AML) were simultaneously determined by two different spectrofluorimetric techniques. The first technique depends on direct measurement of the steady‐state fluorescence intensities of ALS and AML at 313 nm and 452 nm upon excitation at 290 and 375 nm, respectively, in a solvent composed of methanol and water (10: 90, v/v) . The second technique utilizes synchronous fluorimetric quantitative screening of the emission spectra of ALS and AML at 272 and 366 nm, respectively using Δλ of 97 nm. Effects of different solvents and surfactants on relative fluorescence intensity were studied. The method was validated according to ICH guidelines. Linearity, accuracy and precision were found to be satisfactory in both techniques over the concentration ranges of 1–15 and 0.4–4 µg/mL for ALS and AML, respectively. In the first technique, limit of detection and limit of quantification were estimated and found to be 0.256 and 0.776 µg/mL for ALS as well as 0.067 and 0.204 µg/mL for AML, respectively. Also, limit of detection and limit of quantification were calculated in the synchronous method and found to be 0.293 and 0.887 µg/mL for ALS as well as 0.034 and 0.103 µg/mL for AML, respectively. The methods were successfully applied for the determination of the two drugs in their co‐formulated tablets. The results were compared statistically with reference methods and no significant difference was found. The developed methods are rapid, sensitive, inexpensive and accurate for the quality control and routine analysis of the cited drugs in bulk and in pharmaceutical preparations without pre‐separation. Copyright © 2014 John Wiley & Sons, Ltd.     

Synthesis of acyloxymethyl ester prodrugs of the transferable protein farnesyl transferase substrate farnesyl methylenediphosphonate

Three isoprenoid diphosphate analogues of farnesyl diphosphate (FPP) where the diphosphate has been replaced by methylene diphosphonate and the negative charges masked by frangible pivaloyloxymethyl (POM) esters were prepared. Farnesyl methylenediphosphonate is a sub-micromolar substrate for protein farnesyl transferase. The tripivaloyloxymethyl esters of isoprenoid methylenediphosphonate have significantly increased lipophilicity and may act as important farnesyl diphosphate prodrugs.     

Impact of UV and Peracetic Acid Disinfection on the Prevalence of Virulence and Antimicrobial Resistance Genes in Uropathogenic Escherichia coli in Wastewater Effluents

Wastewater discharges may increase the populations of pathogens, including Escherichia coli, and of antimicrobial-resistant strains in receiving waters. This study investigated the impact of UV and peracetic acid (PAA) disinfection on the prevalence of virulence and antimicrobial resistance genes in uropathogenic Escherichia coli (UPEC), the most abundant E. coli pathotype in municipal wastewaters. Laboratory disinfection experiments were conducted on wastewater treated by physicochemical, activated sludge, or biofiltration processes; 1,766 E. coli isolates were obtained for the evaluation. The target disinfection level was 200 CFU/100 ml, resulting in UV and PAA doses of 7 to 30 mJ/cm² and 0.9 to 2.0 mg/liter, respectively. The proportions of UPECs were reduced in all samples after disinfection, with an average reduction by UV of 55% (range, 22% to 80%) and by PAA of 52% (range, 11% to 100%). Analysis of urovirulence genes revealed that the decline in the UPEC populations was not associated with any particular virulence factor. A positive association was found between the occurrence of urovirulence and antimicrobial resistance genes (ARGs). However, the changes in the prevalence of ARGs in potential UPECs were different following disinfection, i.e., UV appears to have had no effect, while PAA significantly reduced the ARG levels. Thus, this study showed that both UV and PAA disinfections reduced the proportion of UPECs and that PAA disinfection also reduced the proportion of antimicrobial resistance gene-carrying UPEC pathotypes in municipal wastewaters.     

Effects of catecholamines on ovary morphology, blood concentrations of estradiol-17beta, progesterone, zinc, triglycerides and rate of ovulation in domestic hens

The present study is an attempt to shed more light on the role of epinephrine (EP) and norepinephrine (NE) in regulating ovarian follicular development, folliculogenesis and ovulation in laying hens. Sixty Egyptian local cross females (Mandarah), 50 weeks old, were individually housed and equally divided into three treatments: control (saline, 0.9% NaCl), EP (0.15 mg epinephrine/hen/day) and NE (0.75 mg norepinephrine/hen/day) (n=20). Animals were injected intramuscularly once a day for 15 successive days. At the end of the experimental period, 10 females from each treatment were randomly chosen, weighed and killed by decapitation. Ovaries and oviducts and ovarian follicles were examined. Plasma concentrations of estradiol-17beta, progesterone, zinc and triglyceride were determined. Results indicated that the ovaries of NE- and EP-treated hens were more developed than those of control hens being heavier and containing more yellow yolk-filled follicles. EP or NE significantly increased the ovulation rate and plasma concentrations of estradiol-17beta, progesterone, zinc and triglyceride compared with control treatment. It could be concluded that catecholamines may have a part in promoting ovarian follicular development and in stimulating ovulation in laying hens at the end of their reproductive lives.     

The integrative role of cryo electron microscopy in molecular and cellular structural biology

After gradually moving away from preparation methods prone to artefacts such as plastic embedding and negative staining for cell sections and single particles, the field of cryo electron microscopy (cryo‐EM) is now heading off at unprecedented speed towards high‐resolution analysis of biological objects of various sizes. This ‘revolution in resolution’ is happening largely thanks to new developments of new‐generation cameras used for recording the images in the cryo electron microscope which have much increased sensitivity being based on complementary metal oxide semiconductor devices. Combined with advanced image processing and 3D reconstruction, the cryo‐EM analysis of nucleoprotein complexes can provide unprecedented insights at molecular and atomic levels and address regulatory mechanisms in the cell. These advances reinforce the integrative role of cryo‐EM in synergy with other methods such as X‐ray crystallography, fluorescence imaging or focussed‐ion beam milling as exemplified here by some recent studies from our laboratory on ribosomes, viruses, chromatin and nuclear receptors. Such multi‐scale and multi‐resolution approaches allow integrating molecular and cellular levels when applied to purified or in situ macromolecular complexes, thus illustrating the trend of the field towards cellular structural biology.     

Assessment of grain quality in terms of functional group response to elevated [CO2], water,and nitrogen using a meta‐analysis: Grain protein,zinc, and iron under future climate

The increasing [CO₂] in the atmosphere increases crop productivity. However, grain quality of cereals and pulses are substantially decreased and consequently compromise human health. Meta‐analysis techniques were employed to investigate the effect of elevated [CO₂] (e[CO₂]) on protein, zinc (Zn), and iron (Fe) concentrations of major food crops (542 experimental observations from 135 studies) including wheat, rice, soybean, field peas, and corn considering different levels of water and nitrogen (N). Each crop, except soybean, had decreased protein, Zn, and Fe concentrations when grown at e[CO₂] concentration (≥550 μmol/mol) compared to ambient [CO₂] (a[CO₂]) concentration (≤380 μmol/mol). Grain protein, Zn, and Fe concentrations were reduced under e[CO₂]; however, the responses of protein, Zn, and Fe concentrations to e[CO₂] were modified by water stress and N. There was an increase in Fe concentration in soybean under medium N and wet conditions but nonsignificant. The reductions in protein concentrations for wheat and rice were ~5%–10%, and the reductions in Zn and Fe concentrations were ~3%–12%. For soybean, there was a small and nonsignificant increase of 0.37% in its protein concentration under medium N and dry water, while Zn and Fe concentrations were reduced by ~2%–5%. The protein concentration of field peas decreased by 1.7%, and the reductions in Zn and Fe concentrations were ~4%–10%. The reductions in protein, Zn, and Fe concentrations of corn were ~5%–10%. Bias in the dataset was assessed using a regression test and rank correlation. The analysis indicated that there are medium levels of bias within published meta‐analysis studies of crops responses to free‐air [CO₂] enrichment (FACE). However, the integration of the influence of reporting bias did not affect the significance or the direction of the [CO₂] effects.