Prediction and estimation of effective population size

Effective population size (Ne) is a key parameter in population genetics. It has important applications in evolutionary biology, conservation genetics and plant and animal breeding, because it measures the rates of genetic drift and inbreeding and affects the efficacy of systematic evolutionary forces, such as mutation, selection and migration. We review the developments in predictive equations and estimation methodologies of effective size. In the prediction part, we focus on the equations for populations with different modes of reproduction, for populations under selection for unlinked or linked loci and for the specific applications to conservation genetics. In the estimation part, we focus on methods developed for estimating the current or recent effective size from molecular marker or sequence data. We discuss some underdeveloped areas in predicting and estimating Ne for future research.

Beta-3 adrenergic agonists reduce pulmonary vascular resistance and improve right ventricular performance in a porcine model of chronic pulmonary hypertension

Beta-3 adrenergic receptor (β3AR) agonists have been shown to produce vasodilation and prevention of ventricular remodeling in different conditions. Given that these biological functions are critical in pulmonary hypertension (PH), we aimed to demonstrate a beneficial effect of β3AR agonists in PH. An experimental study in pigs (n = 34) with chronic PH created by pulmonary vein banding was designed to evaluate the acute hemodynamic effect and the long-term effect of β3AR agonists on hemodynamics, vascular remodeling and RV performance in chronic PH. Ex vivo human experiments were performed to explore the expression of β3AR mRNA and the vasodilator response of β3AR agonists in pulmonary arteries. Single intravenous administration of the β3AR agonist BRL37344 produced a significant acute reduction in PVR, and two-weeks treatment with two different β3AR selective agonists, intravenous BRL37344 or oral mirabegron, resulted in a significant reduction in PVR (median of −2.0 Wood units/m² for BRL37344 vs. +1.5 for vehicle, p = 0.04; and −1.8 Wood units/m² for mirabegron vs. +1.6 for vehicle, p = 0.002) associated with a significant improvement in magnetic resonance-measured RV performance. Histological markers of pulmonary vascular proliferation (p27 and Ki67) were significantly attenuated in β3AR agonists-treated pigs. β3AR was expressed in human pulmonary arteries and β3AR agonists produced vasodilatation. β3AR agonists produced a significant reduction in PVR and improved RV performance in experimental PH, emerging as a potential novel approach for treating patients with chronic PH.

A Potential Biofilm Metabolite Signature for Caries Activity - A Pilot Clinical Study

BACKGROUND

This study's aim was to compare the dental biofilm metabolite-profile of caries-active (N=11) or caries-free (N=4) children by gas chromatography-mass spectrometry (GC/MS) analyses.

METHODS

Samples collected after overnight fasting, with or without a previous glucose rinse, were combined for each child based on the caries status of the site, re-suspended in ethanol and analyzed by GC/MS.

RESULTS

Biofilm from caries-active sites exhibited a different chromatographic profile compared to caries-free sites. Qualitative and quantitative analysis suggested a special cluster of branched alcohols and esters present at substantially higher intensity in biofilms of caries-active sites.

CONCLUSIONS

This pilot study indicates that there are metabolites present in the biofilm which have the potential to provide a characteristic metabolomics signature for caries activity.

Longitudinal analyses of early lesions by fluorescence: an observational study

Previous caries experience correlates to future caries risk; thus, early identification of lesions has importance for risk assessment and management. In this study, we aimed to determine if Quantitative Light-induced Fluorescence (QLF) parameters--area (A [mm(2)]), fluorescence loss (F [%]), and Q [% × mm(2)]--obtained by image analyses can predict lesion progression. We secured consent from 565 children (from 5-13 years old) and their parents/guardians and examined them at baseline and regular intervals over 48 months according to the International Caries Detection Assessment System (ICDAS), yearly radiographs, and QLF. QLF images from surfaces with ICDAS 0/1/2/3/4 at baseline that progressed (N = 2,191) to cavitation (ICDAS 5/6) or fillings and surfaces that did not progress to cavitation/fillings (N = 4,141) were analyzed independently for A, F, and Q. Linear mixed-effects models were used to compare means and slopes (changes over time) between surfaces that progressed and those that did not. QLF A, F, and Q increased at a faster rate for surfaces that progressed than for surfaces that did not progress (p = .0001), regardless of type of surface or baseline ICDAS score. AUC for ICDAS ranged from 0.65 to 0.80, but adding QLF information improved AUC (0.82-0.87, p < .0005). We concluded that faster changes in QLF variables can indicate lesion progression toward cavitation and be more clinically relevant than actual QLF values.

The natural history of dental caries lesions: a 4-year observational study

Dental caries is a ubiquitous disease affecting all age groups and segments of the population. It is known that not all caries lesions progress to cavitation, but little is known regarding the progression pattern of caries lesions. This study's purpose was to evaluate the natural history of dental caries using a standardized, visually based system, the International Caries Detection and Assessment System (ICDAS). The study population consisted of 565 consenting children, who were enrolled and examined at baseline and at regular intervals over 48 months with ICDAS and yearly bitewing radiographs. Of these, 338 children completed all examinations. Not all lesions cavitated at the same rate, differing by surface type and baseline ICDAS severity score and activity status. With increasing severity, the percentage of lesions progressing to cavitation increased: 19%, 32%, 68%, and 66% for ICDAS scores 1, 2, 3, and 4, respectively. Lesions on occlusal surfaces were more likely to cavitate, followed by buccal pits, lingual grooves, proximal surfaces, and buccal and lingual surfaces. Cavitation was more likely on molars, followed by pre-molars and anterior teeth. Predictors of cavitation included age, gender, surfaces and tooth types, and ICDAS severity/activity at baseline. In conclusion, characterization of lesion severity with ICDAS can be a strong predictor of lesion progression to cavitation.

Risk factors of caries progression in a Hispanic school-aged population

The purpose of this Institutional Review Board-approved study was to identify risk factors of caries lesion progression in children enrolled in rural schools in Puerto Rico. A convenience sample of 408 children (5-13 yrs old) was examined at baseline and at 12 and 24 mos with the International Caries Detection and Assessment System (ICDAS). A total of 395 caregivers completed a 25-item questionnaire including socio-demographic, dietary, protective factors, disease experience, and access to care. Caries progression was significant (89% and 91% at 12 and 24 mos, respectively). Multiple-variable models for predicting children with lesion progression and numbers of lesions progressing were calculated for 2 outcome variables (any-progression vs. progression-toward-cavitation). Models developed had areas under the receiver operating characteristic (ROC) curve ranging between 0.70 and 0.79 and were very similar regardless of the outcome (progression criteria), prediction time (12-24 mos), or inclusion (or not) of previous caries experience. Significant predictors of disease progression collected through a parent-completed questionnaire included questions related to caries experience in the child or caregiver, and the caregiver's rating of the child's oral health.

Ageing, health and medication consumption in a sample of academic employees at a Mexican university

Teachers and researchers are valuable resources of universities. A healthy life style includes appropriate utilization of medicines. In this work we explore health status and medicine consumption among a sample of academic employees over 40 years of age at a Mexican university. We analyzed answers to an on line survey in a random sample of academic employees, 40 years and older who work at the National University of Mexico. The 179 item survey was answered from November 2009 to October 2010, by 240 randomly selected academic employees. A section of the questionnaire was oriented toward health issues. We analyzed reported illness, self-perception of health status and medicine consumption. The bodies systems involved most often among those who report any kind of disease were: circulatory and endocrine and/or metabolic, followed by osteomuscular and digestive. Medicinal agents were consumed in the last two weeks by 52% of respondents. Among these, vitamins were consumed by 28%, drugs for pain by 17%, drugs for high blood pressure by 14%, drugs for high cholesterol by 13%, antibiotics by 8%, drugs for diabetes by 5%, cold medicines by 4%. It is suggested that medicinal drugs may not be consumed in situations in which they are indicated, such as in hypercholesterolemia and possibly in hypertension and diabetes. Others, such as vitamins are frequently utilized. Research and interventions should be directed toward better utilization of medicinal drugs.

Use of ICDAS combined with quantitative light-induced fluorescence as a caries detection method

The purpose of this study was to combine a standardized visually based system, the International Caries Detection and Assessment System (ICDAS), with a sensitive fluorescence-based system, quantitative light-induced fluorescence (QLF), to determine the ability to monitor caries lesion progression. This combination (QLF-I) has the potential to increase the sensitivity of the visual method without compromising specificity. A total of 460 children were enrolled and examined at baseline, 8 months and 12 months by ICDAS and QLF by a single examiner. The examiner repeatability for both methods was comparable, varying between weighted kappa of 0.70 and 0.79. The DMFT score was 6.0 (SD 5.8) at baseline and 6.4 (SD 6.3) at 12 months, and both methods were able to follow the increase in incidence. The QLF-I scored more surfaces at the early ICDAS scores (1 and 2) and score 4. Not all lesions progressed at the same rate, differing by score at baseline and surface type.

EEG and behavioral changes following neurofeedback treatment in learning disabled children

Neurofeedback (NFB) is an operant conditioning procedure, by which the subject learns to control his/her EEG activity. On one hand, Learning Disabled (LD) children have higher values of theta EEG absolute and relative power than normal children, and on the other hand, it has been shown that minimum alpha absolute power is necessary for adequate performance. Ten LD children were selected with higher than normal ratios of theta to alpha absolute power (theta/alpha). The Test Of Variables of Attention (TOVA) was applied. Children were divided into two groups in order to maintain similar IQ values, TOVA values, socioeconomical status, and gender for each group. In the experimental group, NFB was applied in the region with highest ratio, triggering a sound each time the ratio fell below a threshold value. Noncontingent reinforcement was given to the other group. Twenty half-hour sessions were applied, at a rate of 2 per week. At the end of the 20 sessions, TOVA, WISC and EEG were obtained. There was significant improvement in WISC performance in the experimental group that was not observed in the control group. EEG absolute power decreased in delta, theta, alpha and beta bands in the experimental group. Control children only showed a decrease in relative power in the delta band. All changes observed in the experimental group and not observed in the control group indicate better cognitive performance and the presence of greater EEG maturation in the experimental group, which suggests that changes were due not only to development but also to NFB treatment.

Human immunodeficiency virus in plasma and cervicovaginal secretions in Filipino women

This study examined 30 HIV-infected women in Manila to assess the relationship between cervicovaginal and plasma HIV-1 viral load. An interview and gynaecologic examination was conducted and cervicovaginal lavage (CVL) and venous blood specimens were collected. HIV-1 RNA was detected in plasma samples of 24 patients (80%) and in CVL samples of 18 women (60%); 16 patients (53%) had detectable levels in both. CVL HIV-1 RNA was detectable in 75% of women (6/8) with plasma viral loads between 10,000 and 100,000 copies/mL and in 77% of women (10/13) with plasma viral loads higher than 100,000 copies/mL (P =0.0086). Among women with CD4 cell counts of less than 200, 200-500, and greater than 500/mm(3), CVL HIV-1 RNA was detected in 73%, 69%, and 17% of women, respectively (P =0.1428). HIV-1 RNA shedding in the genital tract was significantly associated with plasma viral load.

Inhibitory effect against polymerase and ribonuclease activities of HIV-reverse transcriptase of the aqueous leaf extract of Terminalia triflora

Dichloromethane, methanol and aqueous extracts from the leaves of Terminalia triflora were investigated for their inhibitory effect on polymerase and ribonuclease activities of HIV reverse transcriptase.The most potent activity was found in the aqueous extract, which inhibited both polymerase and ribonuclease activities of the enzyme with an IC50 of 1.6 micro g/mL and 1.8 micro g/mL respectively. The antiinfective activity of the extract was demonstrated in HLT4LacZ-IIIB cell culture with an IC50 of 1.0 micro g/mL. The extract was submitted to a purification process by extractive and chromatographic methods. The activity remained in the hydrophillic fraction. Tannins present in this active purified fraction, as determined by TLC and HPLC methods, could account for the anti HIV-RT activity found in the aqueous extract.

Granulocyte colony-stimulating factor induces neutrophils to secrete macrophage colony-stimulating factor

In this work we provide evidence showing that granulocytes produce macrophage colony-stimulating factor (M-CSF) from the band cell stage and secrete this factor when induced to differentiate into polymorphonuclear cells by recombinant human granulocyte colony-stimulating factor (rhG-CSF). Using an enriched population of myeloid band cells from murine bone marrow, we identified the presence of M-CSF with a chromophore-labelled monoclonal anti-M-CSF antibody. Using ELISA we detected the secretion of M-CSF in the supernatants of cultures of enriched band cells when induced with rhG-CSF to differentiate into mature neutrophils. We also found that M-CSF is the only factor responsible for the colony forming activity in the supernatants and lysates of band cells treated with rhG-CSF.

Factors affecting the dimerization of the p66 form of HIV-1 reverse transcriptase

The association and dissociation of the homodimeric p66/p66 form of HIV-1 reverse transcriptase were investigated. The effects on the dimerization process of different salt concentrations, pH and the presence of a template/primer and nucleotide substrates were monitored by measuring polymerase activity and analytical size-exclusion HPLC. At submicromolar concentrations of enzyme and physiological salt concentrations, most of the enzyme exists in the inactive monomeric form. Increasing NaCl concentration from 0.05 to 1 M decreased the equilibrium dissociation constant from 2.0 to 0.34 microM. Analysis of the kinetics of the dimerization process indicated it followed a two-step mechanism, with rapid initial association of the two subunits to form an inactive homodimer followed by a slow isomerization step rendering the active enzyme form. The presence of poly(rA)/dT(20) decreased the equilibrium dissociation constant of the homodimer about 30-fold, while the addition of 5 microM dTTP had no effect. The kinetics of the process showed that the template/primer favored dimerization by binding to the inactive homodimer and promoting its isomerization to the active form. These results were confirmed by analyzing the reverse reaction, i.e. the dissociation of the enzyme, by dilution in a low-ionic-strength buffer. The results suggest that binding of immature HIV-1 reverse transcriptase to its natural template/primer may be relevant in both the dimerization process and the selection of its natural primer.

[Sodium caseinate induces differentiation of 32D pluripotential hematopoietic cells]

AIM

To determine the role of sodium caseinate (CasNa) in the modulation of hemopoiesis.

MATERIALS AND METHODS

32D cells, a murine hemopoietic multipotential cell line dependent on interleukin-3 (IL-3) for proliferation and survival, were used. These cells were cultured with 0.5 ng/mL of IL-3, together with different concentrations of CasNa. We evaluated: proliferation (direct counting under the microscope and use of thymidine 3H), morphological differentiation (giemsa staining), cytochemistry (specific staining for monocytes and granulocytes), and function (presence of Fc receptors and reduction of nitro-blue tetrazolium). In addition, we determined cell viability through trypan blue exclusion and apoptosis using the TUNEL assay in situ.

RESULTS

We showed that CasNa induced a decrease in cell proliferation, which is dose dependent, and is neither a result of a diminished cell viability, nor due to an increase in cell death through apoptosis. In addition, CasNa induces cell differentiation towards the monocytic lineage.

CONCLUSIONS

CasNa has the capacity to differentiate 32D cells towards the monocytic lineage, and, importantly, has a potent differentiating activity on 32D cells being able to promote differentiation in a shorter time than the well known factors G-CSF and GM-CSF.

Sources of abnormal EEG activity in brain infarctions

EEGs from 16 patients with stroke in three different stages of evolution were recorded. EEG sources were calculated every 0.39 Hz by frequency domain VARETA. The main source was within the delta band in 2 out of 4 chronic patients, and in 67% of the patients in the acute or subacute stages when edema (cytotoxic or vasogenic) was present. Moreover, all patients showed abnormal activity in the theta band. Sources of abnormal activity in cortical or corticosubcortical infarcts were located in the cortex, surrounding the lesion. At the site of the infarct, a decrease of EEG power was observed. Sources of abnormal theta power coincided with edema and/or ischemic penumbra.

Correlation between profile of circulating mononuclear cells and clinical manifestations in patients with pemphigus vulgaris

Phenotypes of 38 samples of mononuclear (PBMC) cells from 11 different patients with pemphigus vulgaris (PV) at different stages of the disease were explored looking for a possible relationship between cell immunity, mucocutaneous or mucosal lesion intensity and capacity of serum autoantibodies to elicit the disease in mice. PBMC from 5 patients with mucocutaneous lesions and sera with IgG capable of inducing the disease in neonatal mice had a high proportion of mature monocytes with CD14low DRhigh, and co-expressing CD16 and CD11b. In addition, a high proportion of CD19+CD5+ activated B cells and a very low proportion of naive CD4+CD45RA+ and CD8+CD11b+ T lymphocytes was observed. Monocytes from these patients expressed inducible nitric oxide synthase (iNOS). In contrast, PBMC from 6 patients, with lesions restricted to mucosal membranes and IgG lacking the capacity to induce the disease in mice, contained a high proportion of CD14high DRlow co-expressing CD16 circulating macrophages, CD8+CD11b+ T cells, and a low proportion of activated B lymphocytes. The results suggest a possible association between proportion of different antigen presenting cells (monocytes with high HLA-DR and low CD14 expression and activated B lymphocytes, or differentiated monocytes/macrophages), type of PV and capacity of serum autoantibodies to elicit the disease in mice.