Effects of metformin on recognition memory and hippocampal neuroplasticity in rats with metabolic syndrome

Metabolic syndrome (MS) is a health problem that is characterized by body fat accumulation, hypertension, dyslipidemia, and hyperglycemia; recently, it has been demonstrated that MS also damages memory processes. The first-line drug in the treatment of MS and type 2 diabetes mellitus is metformin, which is an antihyperglycemic agent. This drug has been shown to produce neuroprotection and to improve memory processes. However, the mechanism involved in this neuroprotection is unknown. A 90-day administration of metformin improved the cognitive processes of rats with MS as evaluated by the novel object recognition test, and this finding could be explained by an increase in the neuronal spine density and spine length. We also found that metformin increased the immunoreactivity of synaptophysin, sirtuin-1, AMP-activated protein kinase, and brain-derived neuronal factor, which are important plasticity markers. We conclude that metformin is an important therapeutic agent that increases neural plasticity and protects cognitive processes. The use of this drug is important in the minimization of the damage caused by MS.     

Mutations of the Imprinted CDKN1C Gene as a Cause of the Overgrowth Beckwith–Wiedemann Syndrome: Clinical Spectrum and Functional Characterization

Beckwith–Wiedemann syndrome (BWS) is an imprinting disorder associating macroglossia, abdominal wall defects, visceromegaly, and a high risk of childhood tumor. Molecular anomalies are mostly epigenetic; however, mutations of CDKN1C are implicated in 8% of cases, including both sporadic and familial forms. We aimed to describe the phenotype of BWS patients with CDKN1C mutations and develop a functional test for CDKN1C mutations. For each propositus, we sequenced the three exons and intron–exon boundaries of CDKN1C in patients presenting a BWS phenotype, including abdominal wall defects, without 11p15 methylation defects. We developed a functional test based on flow cytometry. We identified 37 mutations in 38 pedigrees (50 patients and seven fetuses). Analysis of parental samples when available showed that all mutations tested but one was inherited from the mother. The four missense mutations led to a less severe phenotype (lower frequency of exomphalos) than the other 33 mutations. The following four tumors occurred: one neuroblastoma, one ganglioneuroblastoma, one melanoma, and one acute lymphoid leukemia. Cases of BWS caused by CDKN1C mutations are not rare. CDKN1C sequencing should be performed for BWS patients presenting with abdominal wall defects or cleft palate without 11p15 methylation defects or body asymmetry, or in familial cases of BWS.     

Frequency of genetic polymorphisms of PXR gene in the Brazilian population

INTRODUCTION:

PXR polymorphisms have been implicated in modulating CYP3A4 and PXR expression, potentially accounting for interindividual differences in drug metabolism. The prevalence of PXR polymorphisms varies among ethnic groups and data on the allelic distribution in the highly mixed Brazilian population is lacking. The aim of this study was to analyze genetic variations in the PXR gene in Brazilians and to compare the results to other ethnic groups.

METHODS:

DNA samples from 117 healthy Brazilians underwent PCR amplification and sequencing.

RESULTS:

Eleven polymorphisms were identified, 3 of which are highly associated with differences in CYP3A4 expression. We also identified 1 new synonymous variant in 1.3% of the alleles. Among the functional polymorphisms, –25913 C>T and –6994T>C occurred at a higher frequency compared to the African alleles (p < 0.05) but at a lower frequency compared to Caucasian alleles. The 8055 C>T allele was found at a similar frequency to those described in Caucasians and Africans (p > 0.05).

CONCLUSION:

We observed that functional variants of the PXR were frequent in our sample of the Brazilian population. Our results suggest that PXR gene variants may be of interest in pharmacogenetic studies involving Brazilians.     

Following the time course of face gender and expression processing: A task-dependent ERP study

The effects of task demands and the interaction between gender and expression in face perception were studied using event-related potentials (ERPs). Participants performed three different tasks with male and female faces that were emotionally inexpressive or that showed happy or angry expressions. In two of the tasks (gender and expression categorization) facial properties were task-relevant while in a third task (symbol discrimination) facial information was irrelevant. Effects of expression were observed on the visual P100 component under all task conditions, suggesting the operation of an automatic process that is not influenced by task demands. The earliest interaction between expression and gender was observed later in the face-sensitive N170 component. This component showed differential modulations by specific combinations of gender and expression (e.g., angry male vs. angry female faces). Main effects of expression and task were observed in a later occipito-temporal component peaking around 230 ms post-stimulus onset (EPN or early posterior negativity). Less positive amplitudes in the presence of angry faces and during performance of the gender and expression tasks were observed. Finally, task demands also modulated a positive component peaking around 400 ms (LPC, or late positive complex) that showed enhanced amplitude for the gender task. The pattern of results obtained here adds new evidence about the sequence of operations involved in face processing and the interaction of facial properties (gender and expression) in response to different task demands.     

Twenty-year trends in the prevalence of Down syndrome and other trisomies in Europe: impact of maternal age and prenatal screening

This study examines trends and geographical differences in total and live birth prevalence of trisomies 21, 18 and 13 with regard to increasing maternal age and prenatal diagnosis in Europe. Twenty-one population-based EUROCAT registries covering 6.1 million births between 1990 and 2009 participated. Trisomy cases included live births, fetal deaths from 20 weeks gestational age and terminations of pregnancy for fetal anomaly. We present correction to 20 weeks gestational age (ie, correcting early terminations for the probability of fetal survival to 20 weeks) to allow for artefactual screening-related differences in total prevalence. Poisson regression was used. The proportion of births in the population to mothers aged 35+ years in the participating registries increased from 13% in 1990 to 19% in 2009. Total prevalence per 10 000 births was 22.0 (95% CI 21.7–22.4) for trisomy 21, 5.0 (95% CI 4.8–5.1) for trisomy 18 and 2.0 (95% CI 1.9–2.2) for trisomy 13; live birth prevalence was 11.2 (95% CI 10.9–11.5) for trisomy 21, 1.04 (95% CI 0.96–1.12) for trisomy 18 and 0.48 (95% CI 0.43–0.54) for trisomy 13. There was an increase in total and total corrected prevalence of all three trisomies over time, mainly explained by increasing maternal age. Live birth prevalence remained stable over time. For trisomy 21, there was a three-fold variation in live birth prevalence between countries. The rise in maternal age has led to an increase in the number of trisomy-affected pregnancies in Europe. Live birth prevalence has remained stable overall. Differences in prenatal screening and termination between countries lead to wide variation in live birth prevalence.     

An overview of the National Consultative Council of Immunization in Honduras

The State of Honduras instituted its technical advisory committee on immunization in response to recommendations made by the Pan-American Health Organization (PAHO) and the National Extended Program of Immunization (EPI). On 9 October 1999, the “National Consultative Council of Immunization” (NCCI) was established to provide support and recommendations to the EPI program for the eradication, elimination and control of vaccine-preventable diseases. The seven permanent members of the Council are all paediatricians. Additionally, there are liaison members (from PAHO, the national EPI team, and others) who participate in NCCI meetings when required. Meetings take place three times per year. The high quality of Council recommendations is demonstrated by the fact that the health authorities have adopted all of them.     

Interleukin-4-promoted T helper 2 responses enhance Nippostrongylus brasiliensis-induced pulmonary pathology

The role of CD4⁺ T-cell interleukin-4 (IL-4) receptor alpha (IL-4Rα) expression in T helper 2 (TH2) immune responses has not been defined. To examine this role, we infected CD4⁺ T-cell IL-4Rα knockout (KO) mice with the parasitic nematode Nippostrongylus brasiliensis, which induces strong host TH2 responses. Although N. brasiliensis expulsion was not affected in CD4⁺ T-cell IL-4Rα KO mice, the associated lung pathology was reduced. Infected CD4⁺ T-cell IL-4Rα KO mice showed abrogation of airway mucus production. Furthermore, CD4⁺ T-cell IL-4Rα KO mouse lungs contained reduced numbers of lymphocytes and eosinophils. Restimulation of pulmonary region-associated T-cell populations showed that TH2 cytokine responses were disrupted. Secretion of IL-4, but not secretion of IL-13 or IL-5, from mediastinal lymph node CD4⁺ T cells was reduced in infected CD4⁺ T-cell IL-4Rα KO mice. Restimulation of tissue-derived CD4⁺ T cells resulted in equivalent levels of IL-4 and IL-13 on day 7 postinfection (p.i.) in control and CD4⁺ T-cell IL-4Rα KO mice. By day 10 p.i. the TH2 cytokine levels had significantly declined in CD4⁺ T-cell IL-4Rα KO mice. Restimulation with N. brasiliensis antigen of total lung cell populations and populations with CD4⁺ T cells depleted showed that CD4⁺ T cells were a key TH2 cytokine source. These data demonstrated that CD4⁺ T-cell IL-4 responsiveness facilitates eosinophil and lymphocyte recruitment, lymphocyte localization, and TH2 cytokine production in the allergic pathology associated with N. brasiliensis infections.     

Leishmania mexicana DNA activates murine macrophages and increases their TLR9 expression

BACKGROUND: Macrophages are immune system cells that recognize pathogen associated molecular patterns (PAMPs) through receptors that can be located on the cell membrane or in intracellular compartments, such as the TLR (toll like receptors). Different TLRs bind to ligands shared among multiple pathogens. The binding of ligands to TLRs induces a signaling cascade that leads to cytokine and co-stimulatory molecule production due to the nuclear translocation of NF-kappaB. We demonstrated that Leishmania lipophosphoglycan (LPG) is a ligand for TLR2, leading to NK-cell activation. Schieicher et al. recently reported that genomic DNA from Leishmania infantum activates plasmacitoid dendritic cells through TLR9, leading to IFN type I production. OBJECTIVE: In the present study we explored wether Leishmania mexicana DNA contained non-methylated CpG motifs able to activate murine bone marrow derived macrophages, as previously described for bacterial DNA containing CpG motifs. RESULTS AND CONCLUSIONS: We observed that Leishmania mexicana DNA contains non-methylated CpG morifs able ofactivating murine bone marrow derived macrophages, leading to the production of proinflammatory cytokines such as TNFalpha and IL- 12(P40) as well as the over expression of mRNA for TLR9.     

Dose-dependent autonomic dysfunction in chronic L-NAME-hypertensive diabetic rats

This study investigated the effects of varying doses of L-NAME on arterial pressure (AP), baroreflex control, and heart rate (HR)/AP variability in the STZ-diabetic rat. Fifty-two male Wistar rats were injected with 50 mg/kg IV STZ (diabetes, D, n = 24) or citrate (controls, C, n = 28) 30 days before recordings. After 16 days, they received 14 days of oral L-NAME, 10 (H10) or 30 (H30) mg/kg, or water. Catheters were implanted into the femoral artery and vein (PE-10) for measurements in conscious rats; recorded data were analyzed on a beat-to-beat basis. Mean AP was higher in CH30 versus C and in DH10 and DH30 versus D rats. Reflex tachycardia was blunted in CH30 and DH30 rats (b = -1.81, -1.41, -0.48 in C, CH10, and CH30, respectively, P < 0.05 and b = -1.45, -1.19, -0.28 in D, DH10, and DH30, respectively, P < 0.05). Although HR and AP variability were reduced in CH30 and DH30 rats versus C and D rats, the DH30 rat had more accentuated dysfunction. All doses of L-NAME produced similar AP responses in experimental versus control groups, independent of the disease state (diabetes). Thus, autonomic dysfunction is more related to the L-NAME dose used and to the association of diabetes and hypertension than to AP values.     

The laparoscopic management of intersex patients: the preferred approach

In the world's largest series of patients with intersex treated by laparoscopy, authors from Sao Paulo found that this technique allowed easy identification and removal of gonads. They also found that other organs could be removed and genitoplasty performed. OBJECTIVE: To present possibly the largest series of the use of laparoscopy for treating intersex patients. PATIENTS AND METHODS: Fifty intersex patients (34 with male and two with female pseudohermaphroditism, nine with gonadal dysgenesis, four with true hermaphroditism, and one with complex hypospadias), aged 0.5-46 years (mean 18.3), underwent laparoscopy to remove gonads and/or ductal structures incompatible with the social gender, or for gonadal tumour or a potential risk for malignancy. When necessary, genitoplasty was performed concomitantly. RESULTS: At the laparoscopic evaluation, 10 gonads of six patients were absent, while four were identified as 'vanishing'; 72 gonads (46 dysgenetic, 17 normal testes, one normal ovary, one ovotestis, seven gonadoblastomas or dysgerminomas) were removed; two ovotestes were replaced in the scrotum after removing the ovarian segment, as was one normal testis. Twelve patients with a urogenital sinus had its vaginal component removed, 11 including a hysterectomy. Three of these patients had a combined perineal approach to complete its removal, together with masculinizing genitoplasty. There were no intraoperative complications or conversions; two patients had complications after surgery. CONCLUSIONS: Laparoscopy allows the straightforward identification and removal of gonads. All abnormal ductal structures must be removed, as this increases the chance of resecting unidentified gonads. Removing the uterus and vaginal component of the urogenital sinus in patients with male social sex is feasible, with low morbidity. Genitoplasty, according to the social sex, can be performed in the same procedure.