Localization of some steroidogenic enzymes in the ovary of the rabbit

The distribution of delta 5-3 beta-HSD, peroxidase and cytochrome oxidase in immature, sexually mature and pregnant rabbit ovary has been studied histochemically. Corpora lutea are found only in pregnant rabbits. delta 5-3 beta-HSD is present in the theca interna of mature follicles, corpora lutea and interstitial gland cells but is absent in the granulosa cells of both developing and mature follicles. The granulosa cells of mature and developing follicles, hypertrophied theca interna and the luteal cells all show intense cytochrome oxidase activity. Peroxidase is present in the corpora lutea only. It is suggested that delta 5-3 beta-HSD in the theca interna and interstitial gland cells is the enzyme responsible for steroid synthesis in the ovaries of immature as well as sexually mature rabbits, while peroxidase and delta 5-3 beta-HSD present in the corpora lutea together regulate luteal steroidogenesis during pregnancy. The intense cytochrome oxidase activity together with peroxidase and delta 5-3 beta-HSD confirms the observations that this tissue is a site of intense oxidative activity.     

Wastewater: A Potential Bioenergy Resource

Wastewaters are a rich source of nutrients for microorganisms. However, if left unattended the biodegradation may lead to severe environmental hazards. The wastewaters can thus be utilized for the production of various value added products including bioenergy (H₂ and CH₄). A number of studies have reported utilization of various wastewaters for energy production. Depending on the nature of the wastewater, different reactor configurations, wastewater and inoculum pretreatments, co-substrate utilizations along with other process parameters have been studied for efficient product formation. Only a few studies have reported sequential utilization of wastewaters for H₂ and CH₄ production despite its huge potential for complete waste degradation.     

Changes in the levels of superoxide anion radical and superoxide dismutase during the estrous cycle of Rattus norvegicus and induction of superoxide dismutase in rat ovary by lutropin

Superoxide dismutase, which has been shown to be present in a number of tissues, exhibits cyclic changes during the reproductive cycle of rats. An inverse correlation is seen between the levels of superoxide dismutase and superoxide radical. In immature, pseudopregnant rats, primed with human Chorionic Gonadotropin, lutropin seemed to induce ovarian superoxide dismutase, which could be blocked significantly by the introduction of anti-LH serum. These results point out the specific induction of superoxide dismutase by lutropin. It is reasonable to postulate that during luteal functioning, luteinizing hormone induces superoxide dismutase which in turn seems to play a central role generating hydrogen peroxide from superoxide anion radicals. Hydrogen peroxide, thus formed, drives the peroxidase-ascorbate system, responsible for production of progesterone.     

Reversal of Abscisic Acid-Induced Stomatal Closure by trans-Cinnamic and p-Coumaric Acid

Abscisic acid (ABA)-induced increase in stomatal diffusive resistance (SDR) in excised leaves of bean (Phaseolus vulgaris L. cv Pencil Pod) and maize (Zea mays L. cv Golden Bantam) is inhibited by low concentrations of trans-cinnamic acid (TCA) (1 micromolar) and p-coumaric acid (PCA) (10 micromolar) when given together with ABA (10 micromolar) in the transpiration stream through the cut end of the petiole or leaf blade. A concentration effect is observed both in the ABA action and its reversal by phenolic acids. Leaves having attained a high diffusive resistance in ABA solution recover rapidly when transferred to water. ABA (10 micromolar) induced closure of the stomata in onion, Allium cepa L. and Vicia faba epidermal peels. This is associated with loss of K⁺ from guard cells. In the presence of TCA (10 micromolar) and PCA (10 micromolar) K⁺ is retained in the guard cells with open stomata. The dark closure of stomata is also inhibited by TCA and PCA. It is suggested that these phenolic acids may inhibit the ABA effect by competing with or acting on some ABA-specific site, probably located on the plasma membrane, regulating flux of K⁺ ions. A weak association of ABA with the plasma membrane is envisaged because of the rapid recovery obtained upon transferral of the leaves to water.     

Molecular and cellular remodeling of HepG2 cells upon treatment with antitubercular drugs

Drug-induced liver injury (DILI) is an adverse outcome of the currently used tuberculosis treatment regimen, which results in patient noncompliance, poor treatment outcomes, and the emergence of drug-resistant tuberculosis. DILI is primarily caused by the toxicity of the drugs and their metabolites, which affect liver cells, biliary epithelial cells, and liver vasculature. However, the precise mechanism behind the cellular damage attributable to first-line antitubercular drugs (ATDs), as well as the effect of toxicity on the cell survival strategies, is yet to be elucidated. In the current study, HepG2 cells upon treatment with a high concentration of ATDs showed increased perforation within the cell, cuboidal shape, and membrane blebbing as compared with control/untreated cells. It was observed that ATD-induced toxicity in HepG2 cells leads to altered mitochondrial membrane permeability, which was depicted by the decreased fluorescence intensity of the MitoRed tracker dye at higher drug concentrations. In addition, high doses of ATDs caused cell damage through an increase in reactive oxygen species production in HepG2 cells and a simultaneous reduction in glutathione levels. Further, high dose of isoniazid (50–200 mM), pyrazinamide (50–200 mM), and rifampicin (20–100 µM) causes cell apoptosis and affects cell survival during toxic conditions by decreasing the expression of potent autophagy markers Atg5, Atg7, and LC3B. Thus, ATD-mediated toxicity contributes to the reduced ability of hepatocytes to tolerate cellular damage caused by altered mitochondrial membrane permeability, increased apoptosis, and decreased autophagy. These findings further emphasize the need to develop adjuvant therapies that can mitigate ATD-induced toxicity for the effective treatment of tuberculosis.     

Effect of phenolic compounds on abscisic acid-induced stomatal movement: Structure – activity relationship

Application of abscisic acid (ABA) brings about stomatal closure within 30 min in epidermal peels of Vicia faba . A number of phenolic compounds antagonise the effect of ABA. Derivatives of benzoic acid, cinnamic acid, coumarin and flavonoids have been studied in order to establish structure – activity relationship. Derivatives of benzoic acid reverse the ABA effects. Coumarin, esculetin and three hydro derivatives of cinnamic acid fail to show the anti-ABA activity. Thus, the presence of parahydroxyl group and double bond in the side chain is necessary for anti-ABA activity.     

A peptide containing a novel FPGN CD40-binding sequence enhances adenoviral infection of murine and human dendritic cells.

CD40 is a receptor with numerous functions in the activation of antigen presenting cells (APCs), particularly dendritic cells (DC). Using phage display technology, we identified linear peptides containing a novel FPGN/S consensus sequence that enhances the binding of phage to a purified murine CD40-immunoglobulin (Ig) fusion protein (CD40-Ig), but not to Ig alone. To examine the ability the FPGN/S peptides to enhance adenoviral infection of CD40-positive cells, we used bifunctional peptides consisting of an FPGN-containing peptide covalently linked to an adenoviral knob-binding peptide (KBP). One of these, FPGN2-KBP, was able to enhance adenoviral infection of both murine and human DCs in a dose-dependent manner. FPGN2-KBP also improved infection of murine B cell blasts, a murine B lymphoma cell line (L10A), and immortalized human B cells. To demonstrate that enhancement of adenoviral infection depended on the presence of CD40, we analyzed infection of the breast cancer line, SKBR3, that does not express CD40 or the adenovirus cellular receptor, CAR. Infection of SKBR3 cells was enhanced by FPGN2-KBP following transient transfection with a plasmid vector that expresses murine CD40, but not when the cells were mock-transfected. In conclusion, we have isolated a peptide that binds to murine CD40, and promotes the uptake of adenoviruses into CD40-expressing cells of both murine and human origin, suggesting that it may have potential applications for antigen delivery to CD40-positive antigen-presenting cells.     

Over-expression of superoxide dismutase and lack of surface-thiols in spermatozoa: inherent defects in oligospermia.

The infertility associated with oligospermia had been suspected to be a direct consequence of the impairment in fertilizing ability of the spermatozoa rather than the presence of low sperm number per se. This study defines some of these impairments, which include an over expression of superoxide dismutase, poor superoxide anion radical generation capacity and a lack of sperm-surface thiols in oligospermia. The abnormal biochemical make-up of spermatozoa could explain their low fertilizing ability in case of oligospermia.     

Superoxide anion radical induces lipid phase transitions that mimic temperature-induced phase-transition phenomenon of membrane lipids

A biological membrane is shown to undergo lipid-phase transition leading to increased membrane fluidity when exposed to extraneously generated superoxide anion radical. This phase-transition is several folds higher in magnitude when compared to the temperature-induced fluidity change at the transition temperatures. This finding could have significant importance since an altered membrane configuration may involve aspects of biochemistry, biophysics or physiology.