Encapsulation of hemoglobin inside liposomes surface conjugated with poly(ethylene glycol) attenuates their reactions with gaseous ligands and regulates nitric oxide dependent vasodilation

Acellular hemoglobin (Hb)-based O2 carriers (HBOCs) are being investigated as red blood cell (RBC) substitutes for use in transfusion medicine. However, commercial acellular HBOCs elicit both vasoconstriction and systemic hypertension which hampers their clinical use. In this study, it is hypothesized that encapsulation of Hb inside the aqueous core of liposomes should regulate the rates of NO dioxygenation and O2 release, which should in turn regulate its vasoactivity. To test this hypothesis, poly(ethylene glycol) (PEG) conjugated liposome-encapsulated Hb (PEG-LEHs) dispersions were prepared using human and bovine Hb. In this study, the rate constants for O2 dissociation, CO association, and NO dioxygenation were measured for free Hb and PEG-LEH dispersions using stopped-flow UV-visible spectroscopy, while vasoactivity was assessed in rat aortic ring strips using both endogenous and exogenous sources of NO. It was observed that PEG-LEH dispersions had lower O2 release and NO dioxygenation rate constants compared with acellular Hbs. However, no difference was observed in the CO association rate constants between free Hb and PEG-LEH dispersions. Furthermore, it was observed that Hb encapsulation inside vesicles prevented Hb dependent inhibition of NO-mediated vasodilation. In addition, the magnitude of the vasoconstrictive effects of Hb and PEG-LEH dispersions correlated with their respective rates of NO dioxygenation and O2 release. Overall, this study emphasizes the pivotal role Hb encapsulation plays in regulating gaseous ligand binding/release kinetics and the vasoactivity of Hb.     

Chloroplast-encoded chlB gene from Pinus thunbergii promotes root and early chlorophyll pigment development in Nicotiana tabaccum

Chlorophyll biosynthesis is catalyzed by two multi subunit enzymes; a light-dependent and a light-independent protochlorophyllide oxidoreductase. The light-independent enzyme consists of three subunits (ChlL, ChlN and ChlB) in photosynthetic bacteria and plastids in which the chlB gene encodes the major subunit that catalyzes the reduction of protochlorophyllide to chlorophyllide. We report here stable integration of the chlB gene from Pinus thunbergii into the chloroplast genome of tobacco. Using helium-driven biolistic gun, transplastomic clones were developed in vitro. The stable integration and homoplasmy for transgenes was confirmed by using PCR and Southern blotting techniques. Nodal cuttings of the homoplasmic transgenic and untransformed wild type shoots were cultured on MS medium in the dark. As expected, shoots developed from the cuttings of the wild type plants in the dark showed etiolated growth with no roots whereas shoots from the cuttings of the transgenic plants developed early and more roots. Upon shifting from dark to light in growth room, leaves of the transgenic shoots showed early development of chlorophyll pigments compared to the wild type shoots. Further, photosynthetically indistinguishable transgenic shoots also showed significant difference in root development from untransformed wild type shoots when cuttings were grown in the light. Therefore, it may be concluded that the chlB gene is involved, directly or indirectly, in the root development of tobacco. Further, the gene promotes early development of chlorophyll pigments, upon illumination from dark, in addition to its role in the light-independent chlorophyll formation when expressed together with subunits L&N in other organisms.     

Identification of neutral alleles at pollen sterility gene loci of cultivated rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) from wild rice (<Emphasis Type="Italic">O. rufipogon</Emphasis> Griff.)

Oryza rufipogon Griff. is the ancestor of Asian cultivated rice (O. sativa L.) and possesses valuable genes for rice breeding. Pollen abortion is one of the major causes of indica–japonica hybrid sterility in rice and it happens due to allelic interaction at the pollen sterility gene loci. A total of six loci (Sa, Sb, Sc, Sd, Se, and Sf) have been found to be associated with F₁ pollen sterility between indica and japonica rice, and five of them (all except Sf) have been mapped. Neutral alleles (S ⁿ ) at each locus have the potential to overcome the pollen sterility associated with the respective locus. Therefore, exploitation and utilization of neutral alleles have significant importance in overcoming indica–japonica hybrid sterility. In this study, an accession (IRW28) of O. rufipogon, native to China, was selected as paternal to cross with typical japonica (Taichung 65) and indica (Guanglu’ai 4) tester lines, and two F₂ populations were developed. The simple sequence repeat markers tightly linked to five pollen sterility loci were applied for genotyping the F₂ populations. Chi-squared tests were applied to examine the normal segregation/distortion at each locus. The expected and observed pollen sterility for each locus were estimated. As a result, the genotypes at five pollen sterility gene loci for IRW28 were identified as: Sa ⁱ⁻¹/Sa ⁱ⁻¹, Sb ⁿ /Sb ⁿ , Sc ⁱ⁻²/Sc ⁱ⁻², Sd ⁿ /Sd ⁿ and Se ⁿ /Se ⁿ . Our results suggest that IRW28 (O. rufipogon) has the neutral alleles for pollen fertility at the Sb, Sd and Se loci, and these alleles have a good affinity with indica and japonica rice. These neutral alleles provide valuable gene resources to overcome the inter-subspecific hybrid pollen sterility in rice.     

Glutamate Decarboxylase and GABA Aminotransferase Levels in Different Regions of Rat Brain on the Onset of Leptazol Induced Convulsions

The activities of Glutamate decarboxylase (GAD) and Gamma aminobutyric acid (GABA) were studied in three regions of rat brain in heightened neuronal activity resulting in convulsions by Leptazol. These enzymes were studied in preconvulsive, convulsive and post convulsive phases. The activity of GAD decreases significantly in the preconvulsive phase in all the three regions of brain followed by a significant increase during the convulsive and post convulsive phase in cerebral cortex and cerebellum. The activity of GABA-T decreases maximal during the preconvulsive phase followed by convulsive phase. The activity of this enzyme tended to increase to control values when the postconvulsive phase was reached. Therefore, it is suggested that the concomitant decrease of GAD activity and GABA concentration, is probably an important factor in the onset of convulsions.     

Syntheses of 1,2-annulated and 1-spiroannulated carbohydrate derivatives: recent developments

A variety of different strategies has been used for the 1,2-annulation and the 1-spiroannulation of further rings to monosaccharides. This short review presents some recent methods to access such structures involving radical chemistry, cycloadditions, Michael reactions and metal-catalyzed transformations.     

In vivo pharmacological investigation of Monotheca buxifolia and Bosea amherstiana using animal models

Experimental based evidence suggests that most of the medicinal plants possess wide-ranging pharmacological and biological activities that may possibly use in treatment of inflammation-related diseases. The current study was aimed to explore the acute toxicity, analgesic, sedative and antipyretic activities of Monotheca buxifolia and Bosea amherstiana in mices. In vivo experimental models were used in this study. Acute toxicity was evaluated for 24 h’ interval at concentration of 500, 1000, 1500 and 2000 mg/kg. The analgesic activity was estimated by acetic acid induced writhing test. White wood apparatus enclosed in stainless steel was used for sedative experiment and antipyretic activity was evaluated in brewer’s yeast induced hyperthermic at 50, 100 and 150 mg/kg i.p. Both plants were found safe at all tested doses. Monotheca buxifolia and Bosea amherstiana dose-dependently reduced abdominal constrictions in mice. Both plants exhibited significant (P < 0.0001) sedative effects in dose of 50, 150 and 150 mg/kg. Both plants markedly (P < 0.0001) reduced yeast induced hyperthermia. The inhibitions were dose-dependent and remained significant up to five hours of administration. These investigational results have linked a pharmacological indication for the traditional claim of the drugs to be used as an anti-inflammatory, analgesics and antipyretic agents.     

Environmentally induced nephrotoxicity and histopathological alternations in Wallago attu and Cirrhinus mrigla

Fish kidneys are sensitive to chemical changes in the freshwater ecosystem because they are directly and constantly exposed to chemicals dissolved in the water. This study evaluated nephrotoxicity in Wallago attu and Cirrhinus mrigala harvested from the Chenab River in an area of industrial and sewage waste disposal. Induced histological alternation data were correlated to the severity of environmental degradation in order to determine whether this biological system can be used as a tool for environmental monitoring programs. Kidneys from two fish species occupying different niches were collected and stored for 24 h in 10% formalin. Control fish were collected upstream of the polluted river area. Specimens were processed using topical histological methods. The major histological alterations observed in both species were renal tubule myxospora, hyperemia, glomerulonephritis, degeneration of renal tubule cells, dilation of glomerular capillaries, presence of pycnotic nuclei in the hematopoietic tissue, epithelial hypertrophy, vacuolization, reduced lumen of renal tubules, and shrinkage of glomeruli. Renal tubular atrophy, degeneration due to extensive degranulation, necrosis of glomeruli, glomerular expansion, absence of Bowman’s space, hypertrophied nucleus, necrosis and hyalinization of the interstitium, clogging of tubules, and regeneration of tubules was also observed. Wallago attu exhibited the maximum incidence of moderate to severe changes and was defined as having the highest “histopathologic alteration index”. These severe alterations were found to be related to environmental degradation, indicating the presence of stressors in freshwater. Control groups showed normal tissue morphology in the kidneys.     

Regulation of FSH receptor promoter activation in the osteoclast

We have shown recently that FSH stimulates osteoclast formation and function by a direct action on a G(i)-coupled FSH receptor (FSHR). Here, we report properties of the mouse FSH receptor promoter in the context of its activation in RAW-C3 osteoclast precursor macrophages. Basal promoter activity was low, but was significantly stimulated by receptor activator for NF-kappaB-ligand (RANK-L), a critical osteoclastogenic and pro-resorptive cytokine. In contrast, FSH dampened FSHR promoter activation, while estrogen had no effect. We surmise that the FSHR expression is regulated distinctly in the osteoclast, and differently from other cells, such as the ovarian follicular and Leydig cells.