Significant alterations in maternal nutrition may induce long-term metabolic consequences in offspring, in particular obesity and leptin and insulin resistance. Although maternal nutrient deprivation has been well characterized in this context, there is a relative paucity of data on how high fat (HF) nutrition impacts on the subsequent generation. The present study investigated the effects of maternal HF nutrition either throughout the mother's life up to and including pregnancy and lactation or HF nutrition restricted to pregnancy and lactation, on growth and metabolic parameters in male and female offspring. Virgin Wistar rats were assigned to one of three experimental groups: (1) controls (Cont): dams fed a standard chow diet throughout their life and throughout pregnancy and lactation; (2) maternal high fat (MHF) group: dams fed a HF diet from weaning up to and throughout pregnancy and lactation; and (3) pregnancy and lactation high fat (PLHF): dams fed a chow diet through their life until conception and then fed a HF diet throughout pregnancy and lactation. At weaning, all offspring were fed either a chow or HF diet for the remainder of the study (160 days). Litter size and sex ratios were not significantly different between the groups. MHF and PLHF offspring had significantly lower body weights and were hypoleptinaemic and hypoinsulinaemic at birth compared to Cont offspring. As adults however, chow-fed MHF and PLHF offspring were significantly more obese than Cont offspring (DEXA scanning at day 150, P < 0.001 for maternal HF diet). As expected a postweaning HF diet resulted in increased adiposity in all groups; MHF and PLHF offspring, however, always remained significantly more obese than Cont offspring. Increased adiposity in MHF and PLHF offspring was paralleled by hyperinsulinaemia and hyperleptinaemia (P < 0.001; MHF and PLHF versus Cont). It is of interest that a lifetime of HF nutrition produced a similar offspring phenotype to HF nutrition restricted to pregnancy and lactation alone, thus suggesting that the postnatal sequelae of maternal HF nutrition occurs independent of preconceptional diet. These data further reinforce the importance of maternal nutrition during these critical windows of development and show that maternal HF feeding can induce a markedly obese phenotype in male and female offspring completely independent of postnatal nutrition. Obesity and its sequelae may prove to be the greatest threat to human lifestyle and health in the developed world this century (Armitage et al. 2008). The obesity epidemic has seen the incidence of obesity and overweight almost double in Western societies and the trend is mirrored in developing nations that are transitioning to first-world economies. Obesity is strongly associated with the morbidities of type 2 diabetes, hypertension and ischaemic heart disease and represents an enormous burden to the health care system. Of even more concern is the rise of over 40% over the last 20 years in the prevalence of childhood obesity -with concomitant increases...

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Essentials Intracellular calcium pathways regulate megakaryopoiesis but details are unclear.We examined effects of NMDAR‐mediated calcium influx on normal and leukemic cells in culture.NMDARs facilitated differentiation of normal but proliferation of leukemic megakaryocytes.NMDAR inhibitors induced differentiation of leukemic Meg‐01 cells. Background N‐methyl‐d‐aspartate receptors (NMDARs) contribute calcium influx in megakaryocytic cells but their roles remain unclear; both pro‐ and anti‐differentiating effects have been shown in different contexts.ObjectivesThe aim of this study was to clarify NMDAR contribution to megakaryocytic differentiation in both normal and leukemic cells.MethodsMeg‐01, Set‐2, and K‐562 leukemic cell lines were differentiated using phorbol‐12‐myristate‐13‐acetate (PMA, 10 nmol L−1) or valproic acid (VPA, 500 μmol L−1). Normal megakaryocytes were grown from mouse marrow‐derived hematopoietic progenitors (lineage‐negative and CD41a‐enriched) in the presence of thrombopoietin (30‐40 nmol L−1). Marrow explants were used to monitor proplatelet formation in the native bone marrow milieu. In all culture systems, NMDARs were inhibited using memantine and MK‐801 (100 μmol L−1); their effects compared against appropriate controls.ResultsThe most striking observation from our studies was that NMDAR antagonists markedly inhibited proplatelet formation in all primary cultures employed. Proplatelets were either absent (in the presence of memantine) or short, broad and intertwined (with MK‐801). Earlier steps of megakaryocytic differentiation (acquisition of CD41a and nuclear ploidy) were maintained, albeit reduced. In contrast, in leukemic Meg‐01 cells, NMDAR antagonists inhibited differentiation in the presence of PMA and VPA but induced differentiation when applied by themselves.Conclusions NMDAR‐mediated calcium influx is required for normal megakaryocytic differentiation, in particular proplatelet formation. However, in leukemic cells, the main NMDAR role is to inhibit differentiation, suggesting diversion of NMDAR activity to support leukemia growth. Further elucidation of the NMDAR and calcium pathways in megakaryocytic cells may suggest novel ways to modulate abnormal megakaryopoiesis.

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Identification of unknown microorganisms to the species level is an important component of a microbiology course. Modern technologies such as matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing offer a rapid species level identification when compared to conventional phenotype-based methods, however they rely on a well-established taxonomy database and phenotypic assays can still play an important role in species determination. Another major limitation is the up-front cost of purchasing these modern specialized instruments and the requirement of skilled personnel to operate specialized equipment and software, which makes them unsuitable to use in the undergraduate teaching laboratory. Commercial biochemical identification systems such as the Oxoid Microbact™ GNB 12A/12E/24E kit is used for the identification of Enterobacteriaceae and other Gram negative bacteria in clinical and veterinary diagnostic laboratories, and food industries for disease control and treatment. In this article, we describe a method of reliably simulating this Microbact™ strip assay using artificial color liquids (which are affordable and easy to source) for the demonstration of phenotypic characterization of unknown Gram negative organisms while providing a safe teaching environment as no bacteria are used, familiarizing students with the concept of using Microbact™ 12A kit to identify a range of unknown Gram negative organisms.