Comparison of four different methods for detection of rubella IgM antibodies

Four different tests for detection of rubella-specific IgM antibodies were compared: two Ig separation methods (centrifugation and chromatography) with subsequent haemagglutination inhibition test and two commercially available ELISA tests. The 114 sera tested had been sent to the diagnostic laboratory, mostly with insufficient clinical histories. Agreement between the centrifugation method and one of the ELISA tests was good (2 divergent results with 107 sera tested), while the other ELISA test yielded more positive (partly perhaps non-specific) results. The chromatographic method did not separate the Ig classes as reliably as the centrifugation method, but because of its simplicity it may be useful, if adequate test controls are performed. The divergent results are discussed. It is postulated that in cases with pending induced abortion, two independent tests should be performed.     

Recirculating and germinal center B cells differentiate into cells responsive to polysaccharide antigens

Antibodies against bacterial capsular polysaccharides play a critical protective role. Responses to these antigens can occur without the help or control of T cells and are associated with marginal zone (MZ) B cells. Capsular antigens are diverse and some cross-react with self-carbohydrate epitopes. This diversity may explain the recruitment of non-autoreactive recirculating B cells and memory B cells to the MZ in addition to other B cells, some of which are weakly autoreactive cells, that are recruited to the MZ without entering the recirculating pool. To test whether memory B cells respond to polysaccharide-based antigens, mice with hapten-specific memory B cells were challenged with hapten-polysaccharide. Hapten-specific plasma cells producing high affinity antibody with Ig V-region mutations were induced. To test whether naive recirculating B cells can form MZ cells that respond to polysaccharide, recirculating B cells from lymph nodes were transferred into Rag-1-deficient mice. MZ cells differentiated from the donor cells without proliferation or T cell help and responded to polysaccharide-based antigen. The differentiation of B cells both from germinal centers and the recirculating pool to the MZ phenotype is likely to make an important contribution to the repertoire of B cells that respond to polysaccharide antigens.     

Amygdaloid inhibition of maternal behavior in the nulliparous female rat

In the first experiment, the effects of lesions of (1) the amygdala, (2) its major efferent projection system, the stria terminalis or (3) other non-limbic brain sites on the induction of maternal behavior in the nulliparous female rat were investigated. Animals sustaining lesions of either the amygdala or the stria terminalis became maternal more rapidly than did control animals. In the second study the effects of lesions to different portions of the amygdala on both maternal and fear responding were investigated. It was found that animals sustaining damage to the corticomedial amygdaloid nuclei became maternal more quickly than did animals sustaining either basolateral amygdaloid damage or no amygdaloid damage. Also in comparison to lesioned controls, animals with lesions of the amygdala showed reduced ‘fearfulness’ on a number of fear-mediated tasks. The third study attempted to interrelate fear responsiveness and maternal behavior by observing nulliparous animals with amygdaloid or stria terminalis lesions for their responses to unfamiliar foster pups placed daily into their preferred nesting quadrant. While control animals actively avoided pups placed into their nest sites (by moving their nest site to another quadrant of the cage), animals with amygdaloid lesions or lesions of the stria terminalis, did not. These results are interpreted to mean that nulliparous females generally do not respond maternally to pups because these females are, in general, more neophobic than parturient females and they tend to find pups and their novel odors, aversive. This aspect of their behavior is likely mediated by the amygdala. These data are discussed in terms of their relevance to the rapid maternal responsiveness normally shown by the female at parturition.     

Obesity and Circulating Levels of Vitamin D before and after Weight Loss Induced by a Very Low-Calorie Ketogenic Diet

Background: Vitamin D plays a pivotal role in calcium and phosphorus metabolism, also influencing bone tissue. Several studies have reported that vitamin D blood levels were significantly lower in people with obesity, probably due to its uptake by the adipose tissue. Clinical studies that investigated the changes of circulating levels of vitamin D following weight loss reported controversial data. A very low-calorie ketogenic diet is acknowledged as a reliable treatment to achieve a rapid weight loss. Therefore, we investigated the effect of weight loss, consequent to a very low-calorie ketogenic diet, on vitamin D blood concentrations. Methods: A cohort of 31 people with obesity underwent a very low-calorie ketogenic diet for 10–12 weeks. The serum concentrations of vitamin D, parathormone, calcium and phosphorous were measured before and after weight loss; they were compared to a control group of 20 non-obese, non-diabetic, age- and gender-matched persons. Results: Patients with obesity had a higher habitual intake of vitamin D than the control group (p < 0.05). However, the vitamin D blood levels of the obese group were significantly lower than those of the control group (p < 0.005) and they increased after weight loss (p < 0.001). At baseline, vitamin D blood concentrations of the persons with obesity were significantly correlated with both fat mass–kg (r = −0.40; p < 0.05) and body mass index (r = −0.47; p < 0.01). Following very low-calorie ketogenic diet, the change in vitamin D serum concentrations was correlated only with the change in fat mass–kg (r = −0.43; p < 0.01). Conclusion: This study confirmed that patients with obesity have lower vitamin D levels that normalize after significant weight loss, supporting the hypothesis that vitamin D is stored in the adipose tissue and released following weight loss.     

Sarcopenia and Appendicular Muscle Mass as Predictors of Impaired Fasting Glucose/Type 2 Diabetes in Elderly Women

Elderly women exhibit a high risk of type 2 diabetes (T2D), but no definitive data exist about the possible role of postmenopausal increases in visceral adiposity, the loss of lean body mass, or decreases in the sum of the lean mass of arms and legs (appendicular skeletal muscle mass (ASMM)). This retrospective, longitudinal study investigated whether body composition (bioelectrical impedance analysis) predicted the development of impaired fasting glucose (IFG) or T2D in a cohort of 159 elderly women (age: 71 ± 5 years, follow-up: 94 months) from southern Italy (Clinical Nutrition and Geriatric Units of the “Mater Domini” University Hospital in Catanzaro, Calabria region, and the “P. Giaccone ”University Hospital in Palermo, Sicily region). Sarcopenia was defined in a subgroup of 128 women according to the EWGSOP criteria as the presence of low muscle strength (handgrip strength <16 kg) plus low muscle mass (reported as appendicular skeletal muscle mass <15 kg). Participants with a low ASMM had a higher IFG/T2D incidence than those with a normal ASMM (17% vs. 6%, p-adjusted = 0.044); this finding was independent of BMI, fat mass, waist circumference, and habitual fat intake (OR = 3.81, p = 0.034). A higher incidence of IFG/T2D was observed in the subgroup with sarcopenia than those without sarcopenia (33% vs. 7%, p-adjusted = 0.005) independent of BMI and fat mass (OR = 6.75, p = 0.007). In conclusion, this study demonstrates that elderly women with low ASMM had a higher probability of developing IFG/T2D. Further studies are needed to confirm these results in men and in other age groups.     

Adhesiveness of human uterine epithelial RL95-2 cells to trophoblast: rho protein regulation

Embryo implantation involves adhesion of trophoblast cells to the epithelial lining of the endometrium. Using an in-vitro model to simulate this initial interaction, we previously reported that attachment of human trophoblast-like JAR spheroids to human uterine epithelial RL95-2 cells provokes a Ca(2+) influx in RL95-2 cells depending on apically localized integrin receptors. Here, we demonstrate that adhesiveness of RL95-2 cells for JAR spheroids, measured by a centrifugal force-based adhesion assay, is dependent on Rho GTPases, most likely RhoA. Cellular expression and distribution of RhoA were studied by fluorescence confocal microscopy, focusing on the localization of RhoA and F-actin within the adhesion sites between JAR and RL95-2 cells. Contact areas contained high amounts of RhoA and F-actin fibres near the plasma membrane. To determine whether Rho GTPases may influence JAR cell binding, we treated RL95-2 cells with Clostridium difficile toxin A, which specifically inactivates Rho GTPases. Toxin A treatment changed the subcellular distribution of endogenous RhoA in RL95-2 cells and altered RhoA and F-actin colocalization. Adhesion of JAR spheroids to RL95-2 cells treated with toxin A was largely suppressed. These data indicate that Rho GTPases, most likely RhoA, play an important role in uterine epithelial RL95-2 cells for trophoblast binding, and suggest that RhoA may be involved in local signalling cascades during early embryo implantation in vivo.     

A TLC screening program for 170 commonly used pesticides using the corrected Rf value (R f c value)

Summary This article reports TLC data (corrected R_f values; R _f ^c values) of 170 commonly used pesticides which are regularly encountered in toxicological analysis. Silica gel was used as the stationary phase and three binary systems were chosen as solvents.     

Hydrophobic Bombyx mori Silk Fibroin: Routes to Functionalization with Alkyl Chains

Bombyx mori silk fibroin (SF) is a very versatile biopolymer due to its biocompatibility and exceptional mechanical properties which make possible its use as a functional material in several applications. SF can be modified with a large variety of chemical approaches which endow the material with tailored chemical–physical properties. Here, a systematic investigation of different routes is reported to graft long alkyl chains on SF based on both liquid- and solid-phase, aiming to modulate its hydrophobic behavior. The liquid phase method involves direct activation of SF tyrosine residues via diazo coupling and cycloaddition reactions, generating hydrophobic materials insoluble in any common solvent. The solid phase approach consists of the chemical modification of drop-casted SF films by esterification of hydroxyl groups of serine, threonine, and tyrosine SF residues with acyl chlorides of fatty acids. For the solid-state functionalization, a new class of hydrophobic pendant groups is synthesized, based on triple esters of gallic acid anhydrides, that are reacted with the biopolymer to further enhance its resulting hydrophobic features.     

Calcitonin Gene-related Peptide Stimulates the Induction of c-fos Gene Expression in Rat Astrocyte Cultures

The action of calcitonin gene-related pepide (CGRP) was studied on c-fos gene expression in rat astrocyte cultures. A strong and transient increase in c-fos mRNA was observed in cultured astrocytes after treatment with CGRP. Quantitative Northern blot analysis revealed an increase of c-fos mRNA within 15 min, a peak after 30 min with a 10 - 15 fold increase over unstimulated cells and a subsequent decline. Induction of the c-fos gene by CGRP was concentration-dependent, half maximal stimulation of c-fos mRNA being obtained with 100 nM CGRP. The CGRP effect appeared to be mediated by a CGRP receptor and calcitonin was found to mimic only weakly the action of CGRP on cultured astrocytes. Calcitonin transiently induced c-fos gene expression with a similar time course to CGRP, but its effect was much less pronounced. Agents affecting the intracellular cyclic AMP level, forskolin and Ro 20-1724, stimulated c-fos mRNA in a strong and transient fashion with a temporal sequence similar to the response to CGRP. Further, the phosphodiesterase inhibitor Ro 20-1724 potentiated the action of CGRP on c-fos mRNA induction, suggesting a role for cyclic AMP in the action of CGRP. The present results indicate that CGRP may play a physiological role as a regulator of astrocyte gene expression.