Females of the weevil Zabrotes subfasciatus manipulate the size and number of eggs according to the host seed availability

In some insects, the finding of oviposition substrate triggers the uptake into oocytes of yolk proteins that are stored in the fat body during post-embryonic development. The main host of the bean weevil Zabrotes subfasciatus (Coleoptera; Chrysomelidae; Bruchinae; Amblycerini), in which larval resources are the sole source for future egg maturation, is Phaseolus vulgaris. Despite not feeding as adults, females of this species are able to lay eggs after encountering host seeds but it is not known how females react to changes in the availability of bean seeds. In the present study, the behaviour of Z. subfasciatus facing two very different environments for oviposition is investigated, as well as how this influences offspring fitness. The results obtained show that females of Z. subfasciatus react to variations in the availability of seeds belonging to the same host species by adjusting egg size and number. Females on low bean seed density lay larger and fewer eggs than those on high bean seed density, demonstrating a trade-off between these reproductive traits. Moreover, females can adjust egg size to changing levels of host availability during the first 4 days of their oviposition period. Although no difference in offspring weight is found, those from small eggs (low competition environment) result in larger adults. No response to selection on these traits after rearing beetles on the same host for 40 generations is observed. This unresponsiveness may indicate that beetle populations behave according to their reaction norm that already allows rapid adaptation to a varying amount of host-seed availability and better exploitation of the environments of this widespread stored-seed pest.

Hemispheric Lateralization in Benign Focal Epilepsy in Childhood With Centrotemporal Spikes (BECTS)

Benign focal epilepsy in childhood with centrotemporal spikes (BECTS) is one of the most common forms of epilepsy. In adults there is a higher percentage of lateralized epileptic discharges in the left cerebral hemisphere; however, in children this pattern does not seem to have the same distribution. The objective of this study was to evaluate the lateralization of interictal spikes in children with BECTS in relation to the sex of the child and the age of onset of epilepsy. We studied the electroencephalograms (EEGs) of 114 children with a clinical diagnosis of BECTS according to ILAE. The results obtained from two EEGs, performed at intervals of 6 and 12 months, were correlated with the age of onset of the epileptic seizures and the sex of the child. There was no association between the onset of epileptic seizures and the age of the child (p=0.461). When we analyzed the relationship between laterality and sex we did not observe any difference in the first EEG (p = 0.767) results; however, in the results of the second EEG there was a difference (p = 0.002). In males, left and bilateral interictal spikes were predominant, and in females the right hemisphere showed predominant spikes and there were continuous spike-and-wave discharges during slow sleep (CSWSS). The analysis between laterality and a child`s age did not show predominant interictal spikes in the hemispheres, except in males where there were predominant multifocal and generalized spikes, but not lateralization (p=0.011). The conclusion was that in BECTS the lateralization of interictal spikes was not consistent as described in adult patients, but there was a slight left hemispheric predominance in boys and right hemispheric predominance in girls.

Defective NF-kappaB Activation in Response to LPS in Type 1 Diabetes Dendritic Cells

Dendritic cells (DC) are the potent antigen presenting cells which modulate T cell responses to self or non-self antigens. DC play a significant role in the pathogenesis of autoimmune diseases, inflammation and infection, but also in the maintenance of tolerance. NF-kappaB, particularly RelB is a crucial pathway for myeloid DC differentiation and functional maturation. While the current paradigm is that mature, nuclear RelB+ DC prime T cells for immunity/autoimmunity and immature DC for tolerance, RelB-deficient mice paradoxically develop generalised systemic autoimmune inflammatory disease with myelopoiesis and splenomegaly. Previous studies suggested abnormal DC differentiation in healthy relatives of type 1 diabetes (t1dm) patients. Therefore, we compared NF- kB activation in monocyte-derived DC from t1dm and non-t1dm controls in response to LPS. While resting DC appeared normal, DC from 6 out of 7 t1dm patients but no t2dm or rheumatoid arthritis patients failed to translocate NF- kB subunits to the nucleus in response to LPS, along with a failure to up-regulate expression of cell surface CD40 and MHC class I. NF- kB subunit mRNA increased normally in t1dm DC after LPS. Both the classical or non-canonical NF- kB pathways were affected as both TNF-a and CD40 stimulation led to a similarly abnormal NF- kB response. In contrast, expression of phosphorylated p38 MAPK and pro-inflammatory cytokine production was intact. These abnormalities in NF- kB activation appear to be generally and specifically applicable at a post-translational level in t1dm, and have the capacity to profoundly influence immunoregulation in affected individuals.

Environmental control of potential yield of sunflower in the subtropics

A simple framework was used to analyse the determinants of potential yield of sunflower (Helianthus annuus L.) in a subtropical environment. The aim was to investigate the stability of the determinants crop duration, canopy light interception, radiation use efficiency (RUE), and harvest index (HI) at 2 sowing times and with 3 genotypes differing in crop maturity and stature. Crop growth, phenology, light interception, yield, prevailing temperature, and radiation were recorded and measured throughout the crop cycle. Significant differences in grain yield were found between the 2 sowings, but not among genotypes within each sowing. Mean yields (0% moisture) were 6 . 02 and 2 . 17 t/ha for the first sowing, on 13 September (S1), and the second sowing, on 5 March (S2), respectively. Exceptionally high yields in S1 were due to high biomass assimilation associated with the high radiation environment, high light interception owing to a greater leaf area index, and high RUE (1 . 47-1 . 62 g/MJ) across genotypes. It is proposed that the high RUE was caused by high levels of available nitrogen maintained during crop growth by frequent applications of fertiliser and sewage effluent as irrigation. In addition to differences in the radiation environment, the assimilate partitioned to grain was reduced in S2 associated with a reduction in the duration of grain-filling. Harvest index was 0 . 40 in S1 and 0 . 25 in S2. It is hypothesised that low minimum temperatures experienced in S2 reduced assimilate production and partitioning, causing premature maturation.

The p.A2215D Thyroglobulin Gene Mutation Leads to Deficient Synthesis and Secretion of the Mutated Protein and Congenital Hypothyroidism with Wide Phenotype Variation

Context: Thyroglobulin (TG) is a large glycoprotein and functions as a matrix for thyroid hormone synthesis. TG gene mutations give rise to goitrous congenital hypothyroidism (CH) with considerable phenotype variation. Objectives: The aim of the study was to report the genetic screening of 15 patients with CH due to TG gene mutations and to perform functional analysis of the p. A2215D mutation. Design: Clinical evaluation and DNA sequencing of the TG gene were performed in all patients. TG expression was analyzed in the goitrous tissue of one patient. Human cells were transfected with expression vectors containing mutated and wild-type human TG cDNA. Results: All patients had an absent rise of serum TG after stimulation with recombinant human TSH. Sequence analysis revealed three previously described mutations (p. A2215D, p. R277X, and g. IVS30 + 1G > T), and two novel mutations (p. Q2142X and g. IVS46-1G > A). Two known (g. IVS30 + 1G/p. A2215D and p. A2215D/p. R277X) and one novel (p. R277X/g. IVS46-1G > A) compound heterozygous constellations were also identified. Functional analysis indicated deficiency in TG synthesis, reduction of TG secretion, and retention of the mutant TG within the cell, leading to an endoplasmic reticulum storage disease, whereas small amounts of mutant TG were still secreted within the cell system. Conclusion: All studied patients were either homozygous or heterozygous for TG gene mutations. Two novel mutations have been detected, and we show that TG mutation p. A2215D promotes the retention of TG within the endoplasmic reticulum and reduces TG synthesis and secretion, causing mild hypothyroidism. In the presence of sufficient iodine supply, some patients with TG mutations are able to compensate the impaired hormonogenesis and generate thyroid hormone. (J Clin Endocrinol Metab 94: 2938-2944, 2009)

A GPR54-activating mutation in a patient with central precocious puberty

Gonadotropin-dependent, or central, precocious puberty is caused by early maturation of the hypothalamic-pituitary-gonadal axis. In girls, this condition is most often idiopathic. Recently, a G protein-coupled receptor, GPR54, and its ligand, kisspeptin, were described as an excitatory neuroregulator system for the secretion of gonadotropin-releasing hormone (GnRH). In this study, we have identified an autosomal dominant GPR54 mutation - the substitution of proline for arginine at codon 386 (Arg386Pro) - in an adopted girl with idiopathic central precocious puberty (whose biologic family was not available for genetic studies). In vitro studies have shown that this mutation leads to prolonged activation of intracellular signaling pathways in response to kisspeptin. The Arg386Pro mutant appears to be associated with central precocious puberty.

Structure of TcpG, the DsbA protein folding catalyst from Vibrio cholerae

The efficient and correct folding of bacterial disulfide bonded proteins in vivo is dependent upon a class of periplasmic oxidoreductase proteins called DsbA, after the Escherichia coli enzyme. In the pathogenic bacterium Vibrio cholerae, the DsbA homolog (TcpG) is responsible for the folding, maturation and secretion of virulence factors. Mutants in which the tcpg gene has been inactivated are avirulent; they no longer produce functional colonisation pill and they no longer secrete cholera toxin. TcpG is thus a suitable target for inhibitors that could counteract the virulence of this organism, thereby preventing the symptoms of cholera. The crystal structure of oxidized TcpG (refined at a resolution of 2.1 Angstrom) serves as a starting point for the rational design of such inhibitors. As expected, TcpG has the same fold as E. coli DsbA, with which it shares similar to 40% sequence identity. Ln addition, the characteristic surface features of DsbA are present in TcpG, supporting the notion that these features play a functional role. While the overall architecture of TcpG and DsbA is similar and the surface features are retained in TcpG, there are significant differences. For example, the kinked active site helix results from a three-residue loop in DsbA, but is caused by a proline in TcpG (making TcpG more similar to thioredoxin in this respect). Furthermore, the proposed peptide binding groove of TcpG is substantially shortened compared with that of DsbA due to a six-residue deletion. Also, the hydrophobic pocket of TcpG is more shallow and the acidic patch is much less extensive than that of E. coli DsbA. The identification of the structural and surface features that are retained or are divergent in TcpG provides a useful assessment of their functional importance in these protein folding catalysts and is an important prerequisite for the design of TcpG inhibitors. (C) 1997 Academic Press Limited.

The Saskatchewan Pediatric Bone Mineral Accrual Study: Bone mineral acquisition during the growing years

To investigate bone mineral accretion in growing children, the Saskatchewan Pediatric Bone Mineral Accrual Study was initiated in 1991. The study involves the collection of dietary and physical activity information along with anthropometric growth and maturity measurements every 6 months and dual-energy X-ray absorptiometer (DXA) bone scans of the whole body, AP lumbar spine and proximal femur taken annually, The study has now finished its 6th year and 68 males and 72 females from an original sample of 228 elementary schoolchildren are still involved, To investigate how bone mineral at clinically important sites proceeds in relation to maturation we developed distance and velocity growth curves for height and bone mineral content (BMC) for the AP lumbar spine, the femoral neck and the whole body, In both boys and girls, over 35% of total body and AP spine bone mineral and over 27% of the bone mineral at the femoral neck was laid down during the 4-year adolescent period surrounding peak linear growth velocity. The clinical significance of these values can be appreciated by consideration of the fact that as much bone mineral will be laid down during these 4 adolescent growing years as most people will lose during all of adult life.

Molluscum contagiosum: immunomorphological aspects of keratinocytes markers of differentiation and adhesion

Background Molluscum contagiosum (MC) is a Molluscipox virus infection of keratinocytes with hyperplasia and intracytoplasmic inclusions-the molluscum bodies (MBs). Few papers address cytokeratins (K) profile in MC, mainly focusing terminal keratinization process. Methods Forty-one MC lesions were subjected to immunohistochemical technique to verify K1, K10, K14, K16, involucrin, filaggrin, E-cadherin and p63 expression. MC immunolabeling pattern was compared to adjacent normal appearing epidermis (ANAE). Results In MC and ANAE, K1/K10 were expressed in suprabasal layers, K14 was expressed in basal and suprabasal layers and K16 was expressed through all spinous layer. Involucrin and filaggrin were observed in granular, spinous and in basal layer of ANAE and MC. E-cadherin was present up to the first layers of MC while ANAE exhibited E-cadherin labeling at basal and spinous layers. Basal and spinous layers keratinocytes nuclei, in both MC and ANAE, express p63. Conclusion Infection by Molluscipox virus alters keratinocyte differentiation status. The presence of K14 and p63 in spinous layer, as well as early expression of involucrin and filaggrin, associated to a hyperproliferative state disclosed by K16 expression, may be a result of disruption in keratinocytes maturation process. The changes observed at ANAE may represent early events in keratinization disturbance. Callegaro CF, Sotto MN. Molluscum contagiosum: immunomorphological aspects of keratinocytes markers of differentiation and adhesion.

Visuospatial attention disturbance in Duchenne muscular dystrophy

AIM The cognitive deficits present in the Duchenne muscular dystrophy (DMD) are not yet well characterized. Attention, considered to be the brain mechanism responsible for the selection of sensory stimuli, could be disturbed in DMD, contributing, at least partially, to the observed global cognitive deficit. The aim of this study was to investigate attentional function in individuals with DMD. METHOD Twenty-five males (mean age 12y; SD 2y 2mo) with DMD and 25 healthy males (mean age 12y; SD 2y) were tested in a visuospatial task (Posner computerized test). They were instructed to respond as quickly as possible to a lateralized visual target stimulus with the ipsilateral hand. Their attention was automatically orientated by a peripheral prime stimulus or, alternatively, voluntarily orientated by a central spatially informative cue. RESULTS The main result obtained was that the attentional effect (sum of the benefit and the cost of attention) did not differ between the two groups in the case of automatic attention (p=0.846) but was much larger for individuals with DMD than for comparison individuals in the case of voluntary attention (p < 0.001). INTERPRETATION The large voluntary attentional effect exhibited by the participants with DMD seems similar to that of younger children, suggesting that the disease is associated with delayed maturation of voluntary attention mechanisms.

Tone-evoked ABR in full-term and preterm neonates with normal hearing

This study was designed to investigate the feasibility of applying tone-ABRs in the nursery and neonatal intensive care unit (NICU), and to provide normative tone-ABR data from neonates. Normative tone-ABR latency data were determined. The study obtained intensity series of tone-ABRs from thirty preterm neonates and twenty fullterm neonates who had confirmed normal peripheral auditory function after passing both an OAE and ABR screening examination. ABRs were collected in response to 500, 1500, and 4000 Hz tone bursts at 70, 50, 30, and 20 dB nHL. Mean wave V latencies were compared between groups, ears, and by gender. Responses to tone bursts of 20 and 30 dB nHL were detected in 97% and 100% of all ears respectively, in addition to responses to the higher-intensity stimuli. Preterm neonates` ABRs showed significantly longer latencies than those of the full-term infants. Tone-ABR evaluation was found to be both feasible and reliable as a measure of auditory function in neonates.

Non-expression of insulin-like growth factor-I receptor is associated with apoptosis: an ultrastructural study on rat ameloblasts

Insulin-like growth factor-I (IGF-I) is a preiotrophic polypeptide which appears to have roles both as a circulating endocrine hormone and as a locally synthesized paracrine or autocrine tissue factor. IGF-I plays a major role in regulating the growth of cells in vivo and in vitro and initiates metabolic and mitogenic processes in a wide variety of cell types by binding to specific type I receptors in the plasma membrane, In this study, we report the distribution of IGF-I receptors in odontogenic cells at the ultrastructural level using the high resolution protein A-gold technique, In the pre-secretory stage, very little gold label was visible over the ameloblasts and odontoblasts, During the secretory stage the label was mostly seen in association with the cell membranes and endoplasmic reticulum of the ameloblasts. Lysosome-like elements in the post-secretory stage were labelled as well as multivesicular dense bodies, Very little labelling was encountered in the ameloblasts in the transitional stage, where apoptotic bodies were clearly visible, The maturation stage also exhibited labelling of the secretory-like granules in the distal surface. The presence of gold particles over the plasma membrane is an indication that IGF-I receptor is a membrane-bound receptor. Furthermore, the intracellular distribution of the label over the endoplasmic reticulum supports the local synthesis of the IGF-I receptor. The absence of labelling over the transitional ameloblasts suggests that the transitional stage may require the non-expression of IGF-I as a prerequiste or even a trigger for apoptosis.

Major histocompatibility complex (MHC) class II-positive dendritic cells in the rat iris - In situ development from MHC class II-negative precursors

Purpose. To examine the postnatal development of major histocompatibility complex (MHC) class II-positive dendritic cells (DC) in the iris of the normal rat eye. Methods. Single-and double-color immunomorphologic studies were performed on whole mounts prepared from rat iris taken at selected postnatal ages (2 to 3 days to 78 weeks). Immunopositive cells were enumerated, using a quantitative light microscope, and MHC class II expression on individual cells was assessed by microdensitometric analysis. Results. Major histocompatibility class II-positive DCs in the iris developed in an age-dependent manner and reached adult-equivalent density and structure at approximately 10 weeks of age, considerably later than previously described in other DC populations in the rat. In contrast, the anti-rat DC monoclonal antibody OX62 revealed a population of cells present at adult-equivalent levels as early as 3 weeks after birth. Dual-color immunostaining and microdensitometric analysis demonstrated that during postnatal growth, development of the network of MHC class II-positive DCs was a consequence of the progressive increase in expression of MHC class II antigen by OX62-positive cells. Conclusions. During postnatal growth, the DC population of the iris develops initially as an OX62-positive-MHC class II-negative population, which then develops increasing MHC class II expression in situ and finally resembles classic DC populations in other tissue sites. Maturation of the iris DC population is temporally delayed compared with time to maturation in other tissue sites in the rat.

Limited Ca(2+) and PKA-pathway dependent neurogenic differentiation of human adult mesenchymal stem cells as compared to fetal neuronal stem cells

The ability of mesenchymal stem cells to generate functional neurons in culture is still a matter of controversy. In order to assess this issue, we performed a functional comparison between neuronal differentiation of human MSCs and fetal-derived neural stem cells (NSCs) based on morphological, immunocytochemical, and electrophysiological criteria. Furthermore, possible biochemical mechanisms involved in this process were presented. NF200 immunostaining was used to quantify the yield of differentiated cells after exposure to CAMP. The addition of a PKA inhibitor and Ca(2+) blockers to the differentiation medium significantly reduced the yield of differentiated cells. Activation of CREB was also observed on MSCs during maturation. Na(+)-, K(+)-, and Ca(2+)-voltage-dependent currents were recorded from MSCs-derived cells. In contrast, significantly larger Na(+) currents, firing activity, and spontaneous synaptic currents were recorded from NSCs. Our results indicate that the initial neuronal differentiation of MSCs is induced by CAMP and seems to be dependent upon Ca(2+) and the PKA pathway. However, compared to fetal neural stem cells, adult mesenchymal counterparts are limited in their neurogenic potential. Despite the similar yield of neuronal cells, NSCs achieved a more mature functional state. Description of the underlying mechanisms that govern MSCs` differentiation toward a stable neuronal phenotype and their limitations provides a unique opportunity to enhance our understanding of stem cell plasticity. (C) 2009 Elsevier Inc. All rights reserved.

Protein profile of the luteal phase endometrium by tissue microarray assessment

To investigate the luteal phase endometrial expression of leukemia inhibitor factor (LIF), insulin-like growth factor 1 (IGF-1), progesterone receptor (PR), claudin 4 (CLDN4), vascular-endothelial growth factor receptor 3 (VEGFR-3), bone morphogenetic protein 4 (BMP-4) and citokeratin 7 (CK-7), we obtained luteal phase endometrial samples from 52 women. Samples were dated and integrated using a tissue microarray (TMA). Samples were immunostained for LIF, IGF-1, PR, CLDN4, VEGFR-3, BMP-4 and CK-7. Frequencies of positive expressions at the early, mid and late luteal phases were compared by two proportions test. Concomitant expression of these proteins was assessed with Chi-square or Fischer`s test. The frequency of LIF was positively correlated to the frequency of IGF-1 (r = 0.99; p < 0.05) and PR (r = 0.99; p < 0.05), and the correlation between IGF-1 and PR tended to be significant (r = 0.98; p < 0.1). The expression of PR was associated with the absence of CLDN4 (p < 0.001). Thus, expression of LIF, IGF-1 and PR are correlated during the luteal phase, and immunohistochemistry for these proteins might be used to assist in the assessment of endometrial maturation. In addition, the expression of CLDN4 and PR was not concomitant, warranting further investigation on the relationship of their endometrial expression.