Effects of acute or chronic administration of desmethylimipramine on the local level of methionine incorporation in cerebral proteins in freely moving rats

Incorporation of methionine into brain proteins has been measured by quantitative autoradiography after desmethylimipramine administration in rats. Acute treatment decreased protein synthesis in three regions: hippocampus, hypothalamus and habenula. After chronic treatment the decrease extended to four other regions: substantia nigra, raphe dorsalis, trigeminal nerve and hypophysis. An opposite effect was observed in the retrosplenial cortex.     

Continuous-time modeling of cell fate determination in Arabidopsis flowers

Background  

The genetic control of floral organ specification is currently being investigated by various approaches, both experimentally and through modeling. Models and simulations have mostly involved boolean or related methods, and so far a quantitative, continuous-time approach has not been explored.     

The Emerging Role of Copeptin

Direct measurement of the nonapeptide vasopressin has been limited by analyte instability ex vivo and in vivo rapid degradation, low serum concentrations requiring a sensitive assay and inherent secretory pulsatility. Copeptin is a 39 amino acid glycopeptide cleavage product of vasopressin synthesis with high stability, providing a marker of vasopressin secretion. Copeptin measurement has applications in diagnosis of diabetes insipidus and other diseases with altered vasopressin secretion. This review summarises our current understanding of serum copeptin measurement in diabetes insipidus and possible future applications of copeptin assays. As vasopressin is a stress hormone, there is emerging evidence on the use of copeptin for diagnosis and prognostication of disorders such as syndrome of inappropriate anti-diuretic hormone secretion, diabetes mellitus, critical illness, stroke, cardiovascular disease, respiratory disease, renal disease and thermal stress. Copeptin concentration measurement is likely to improve the diagnostic reliability of diabetes insipidus and, as a marker of stress, may have diagnostic or prognostic utility in specific clinical circumstances. Further studies are needed to determine if goal-directed therapy using plasma copeptin concentrations may improve patient outcomes.     

Production of interleukin-1 receptor antagonist isoforms by microglia in mixed rat glial cells stimulated by lipopolysaccharide

Although the natural interleukin-1 receptor antagonist (IL-1Ra) has been shown to be produced by microglial cells in response to immune stimuli, nothing was known about the ability of these cells in primary culture to produce the different isoforms of IL-1Ra. Using RT-PCR, we first confirmed that mixed glial cell cultures from newborn rats respond to the cytokine inducer, lipopolysaccharide, by synthesizing IL-1Ra mRNA. Using double immunostaining, we showed that IL-1Ra was detected in microglia but not in astrocytes. Using Western blotting, we finally demonstrated that the IL-1Ra1 isoform was secreted in the supernatant of mixed glial cell cultures, and its production increased in response to lipopolysaccharide. The three different IL-1Ra isoforms were constitutively expressed in cell lysates and their levels increased after lipopolysaccharide treatment, except for IL-1Ra3. These results point to the ability of microglial cells in primary culture to produce the different isoforms of IL-1Ra.     

Film formation from colloidal dispersions stabilized by sugar derivatives and their controllable release for selective protein adsorption

Although the use of sugar and sugar derivatives has been documented in polymer research for many years, there are no reports that would utilize these species as polymerization sites of colloidal polymeric particles that, later on, may be released during particle coalescence to form films with surfaces that differentiate protein adsorption. These studies show that, when n-dodecyl-beta-D-maltoside (DDM) is utilized for the synthesis and stabilization of poly[methyl methacrylate-co-(n-butyl acrylate)] (p-MMA/nBA) colloidal particles, upon particle coalescence DDM stratifies near the film-air (F-A) interface. By using attenuated total reflectance Fourier transform infrared (ATR FT-IR) spectroscopy and internal reflection infrared imaging (IRIRI), comparative adsorption studies on p-MMA/nBA surfaces exposed to globulin (Glo), fibrinogen (Fib), and bovine serum albumin (BSA) reveal that the presence of DDM selectively inhibits Glo and Fib adsorption, but does not affect BSA. The presence of DDM also enhances the rate of mobility of sodium dioctylsulfosuccinate (SDOSS) resulting from interactions between DDM and SDOSS moieties, and the surface morphologies change as a result of concentration variations of DDM in the colloidal dispersions.     

Stimuli-responsive surfactant/phospholipid stabilized colloidal dispersions and their film formation

Methyl methacrylate (MMA) and n-butyl acrylate (nBA) were copolymerized into stable colloidal particles in the presence of micelle forming sodium dioctyl sulfosuccinate (SDOSS) and liposome forming 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) in aqueous media that serve as thermodynamically stable loci for lipophilic monomers and nanostructured templates. These studies show for the first time that hollow colloidal particles may coalesce to form polymeric films and the combination of SDOSS and DLPC dispersing agents provides a stimuli-responsive environment during film formation through which individual surface stabilizing components can be driven to the film-air (F-A) or film-substrate (F-S) interface. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) of p-MMA/nBA colloidal dispersions revealed preferential and enhanced mobility of SDOSS and DLPC lipid rafts to the F-A and F-S interfaces in response to thermal, ionic, and enzymatic stimuli.     

ANTHROPOMETRIC DETERMINANTS OF ROWING ERGOMETER PERFORMANCE IN PHYSICALLY INACTIVE COLLEGIATE FEMALES

The aim of the study was to evaluate anthropometric characteristics as determinants of 500 m rowing ergometer performance in physically inactive collegiate females. In this cross-sectional study, which included 196 collegiate females aged 19-23 years not participating in regular physical activities, body mass (BM), body height (BH), length of upper limbs (LA), length of lower limbs (LL), body mass index (BMI), slenderness index (SI), and the Choszcz-Podstawski index (CPI) were measured and a stepwise multiple regression analysis was performed. Participants performed 500 m maximal effort on a Concept II rowing ergometer. BM, BH, LA, LL, and the BMI, SI and CPI indices were found to be statistically significant determinants of 500 m performance. The best results (T) were achieved by females whose BH ranged from 170 to 180 cm, with LA and LL ranging from 75 to 80 cm and 85 to 90 cm, respectively. The best fitting statistical model was identified as: T = 11.6793 L_R – 0.1130 L_R² – 0.0589 L_N² + 29.2157 CPI² + 0.1370 LR·LN - 2.6926 LR·CPI – 211.7796. This study supports a need for additional studies focusing on understanding the importance of anthropometric differences in rowing ergometer performance, which could lead to establishing a better quality reference for evaluation of cardiorespiratory fitness tested using a rowing ergometer in collegiate females.