Thiocarbohydrazide-crosslinked chitosan as a bioinspired corrosion inhibitor for protection of stainless steel in 3.5% NaCl

A facile single-step synthesis was performed to cross-link chitosan with thiocarbohydrazide to yield thiocarbohydrazide-chitosan (TC-Cht) which was for the first time evaluated as an inhibitor for corrosion of stainless steel in 3.5% NaCl solution. A comprehensive electrochemical analysis employing electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and cyclic voltammetry (CV) was undertaken and showed that the TC-Cht acts by adsorption on the steel surface and exhibits mixed type behavior with predominantly cathodic nature. The adsorption of TC-Cht molecules on the surface of stainless steel followed the Langmuir isotherm. The TC-Cht showed a high inhibition efficiency of >94% at 500 mg L^?1 concentration. Surface investigation using SEM and EDX supported the inhibitor adsorption on the steel surface.     

Lack of Amphetamine-Like Effects After Administration of Mefenorex in Normal Young Subjects

Mefenorex is an indirect sympathomimetic amine which acts as an anorectic drug and is used in combination with low diet to treat excess weight. The central nervous system (CNS) effects of mefenorex were assessed in a randomized, double-blind, three-way cross-over, placebo-controlled study involving nine healthy young male volunteers. They received either a single oral dose of mefenorex 80 mg (twice the recommended dose) or d-amphetamine sulfate 18 mg or a placebo at 1-week intervals. CNS pharmacodynamic measurements consisted of subjective evaluation (visual analogue scales and the Addiction Research Centre inventory (ARCI)), EEG, psychomotor performance and attention (tracking, simple and choice reaction times, tapping, continuous performance task, DSST, body sway) and memory (working memory and recall of a word list). d-Amphetamine produced a typical psychostimulant EEG profile (significant decrease in slow delta waves and increase in fast beta activities), significantly increased amphetamine, benzedrine and morphine–benzedrine scores of ARCI and significantly decreased body sway compared to placebo and mefenorex. A trend in favour of a stimulant effect occurred for all other parameters (particularly speed of reaction) and no changes of memory were noticed. In contrast, mefenorex did not produce an amphetamine-like EEG profile, neither significantly changed ARCI scores nor significantly modified psychomotor and memory performance compared to the placebo, although it induced a decrease in body sway. In conclusion, the present results indicate that a single oral dose of mefenorex, at twice the recommended daily dose, does not possess amphetamine-like subjective and EEG stimulant effects or sensations of well-being, often encountered with drugs of abuse liability potential, in a healthy young population.     

Plasticity of autonomic nerves: Differential effects of long-term guanethidine sympathectomy on the sensory innervation of the rat uterus during maturation

The sensory nerves, containing substance P and calcitonin gene-related peptide, and noradrenaline-containing sympathetic nerves of the rat uterus were analyzed following long-term sympathectomy with guanethidine in prepubertal (four weeks), young adult (eight weeks) and fully adult animals (18 weeks). Immunohistochemical and histochemical methods were used in association with nerve density measurements and biochemical assays. The main findings were as follows:

1. (1) long-term guanethidine treatment completely abolished the noradrenergic innervation of the uterine horn and parametrial tissue and markedly reduced the tissue levels of noradrenaline in both regions at the three ages analysed;

2. (2) in the uterine hom guanethidine treatment had no effect on the tissue levels of either calcitonin gene-related peptide or substance P or on the density of calcitonin gene-related peptide-containing nerves, at any of the three ages studied;

3. (3) in the parametrial tissue increased levels of calcitonin gene-related peptide were observed at 8 and 18 weeks of age, together with a significant increase in the density of calcitonin gene-related peptide-containing nerves.

Substance P levels showed a transient increase in this tissue at eight weeks. In conclusion, long-term sympathectomy with guanethidine resulted in an increase in calcitonin gene-related peptide and substance P in sensory nerves in the parametrial tissue, but not in the uterine horn. The changes in the parametrial tissue only occurred after puberty. It is suggested that sensory nerves in the uterine horn may be less responsive to sympathetic denervation since loss of sympathetic nerves occurs as part of a normal physiological process during pregnancy in this region.

An endogenous glycosylphosphatidylinositol-specific phospholipase D releases basic fibroblast growth factor-heparan sulfate proteoglycan complexes from human bone marrow cultures

Basic fibroblast growth factor (bFGF) is a hematopoietic cytokine that stimulates stromal and stem cell growth. It binds to a glycosylphosphatidylinositol (GPI)-anchored heparan sulfate proteoglycan on human bone marrow (BM) stromal cells. The bFGF- proteoglycan complex is biologically active and is released by addition of exogenous phosphatidylinositol-specific phospholipase C. In this study, we show the presence of an endogenous GPI-specific phospholipase D (GPI-PLD) that releases the bFGF-binding heparan sulfate proteoglycan and the variant surface glycoprotein (a model GPI-anchored protein) from BM cultures. An involvement of proteases in this process is unlikely, because released proteoglycan contained the GPI anchor component, ethanol-amine, and protease inhibitors did not diminish the release. The mechanism of release is likely to involve a GPI-PLD and not a GPI-specific phospholipase C, because the release of variant surface glycoprotein did not reveal an epitope called the cross- reacting determinant that is exposed by phospholipase C-catalyzed GPI anchor cleavage. In addition, phosphatidic acid (which is specifically a product of GPI-PLD-catalyzed anchor cleavage) was generated during the spontaneous release of the GPI-anchored variant surface glycoprotein. We also detected GPI-PLD-specific enzyme activity and mRNA in BM cells. Therefore, we conclude that an endogenous GPI-PLD releases bFGF-heparan sulfate proteoglycan complexes from human BM cultures. This mechanism of GPI anchor cleavage could be relevant for mobilizing biologically active bFGF in BM. An endogenous GPI-PLD could also release other GPI-anchored proteins important for hematopoiesis and other physiologic processes.     

Study of nuclear diameters in non-Hodgkin's lymphomas

The mean maximum nuclear diameter (D_max) in 21 cases of non-Hodgkin's lymphoma (NHL) has been determined, using the Reichert-Jung (Kontron) MOP-AMO₃ user-controlled image analyser. Nuclear diameters of high-grade malignancy NHL were found to be considerably greater than those of low-grade malignancy lymphomas, although there was some overlap of their ranges. These findings confirm objectively subjective estimates of nuclear size in NHL. The relative usefulness of the user-controlled (interactive) image analyser for the measurement of nuclei in tissue sections is compared with that of a fully automatic machine.