Genetic variability in the Guahibo population from venezuela

Four communities from Guahibo of Venezuela were analyzed for the genetic variants of nine erythrocyte enzymes and five serum proteins. Of the 14 loci determined, four were monomorphic. Significant frequency differentiation among communities, was present for ESD and TF markers. In general, Guahibo allele frequencies are in the variation ranges described for South American groups. The analysis indicates a relatively higher affinity of Guahibos with other Venezuelan groups within an irregular pattern of genetic distances that are likely related to the complex demographic history of the South American groups. Genetic diversity estimates reveal a moderate degree of genetic structure between the four Guahibo communities. This intra‐tribal variability in Guahibo appears to be lower than in Venezuelan Piaroa but higher than in other Amerindians and could be attributed to a combined effect of low population size and relative isolation of communities. At a continental level, the distribution of genetic diversity is consistent with preferential population movements along the eastern and western coastal areas. Am. J. Hum. Biol. 14:21–28, 2002. © 2002 Wiley‐Liss, Inc.     

Comparison of latex agglutination with enzyme immunoassay for detection of rotavirus in fecal specimens

Human rotaviruses are the most important etiologic agents of acquired diarrhea in infants and young children worldwide. Early diagnosis is essentialfor effective patient treatment. The latex agglutination (LA) assays for rotavirus diagnosis are rapid, inexpensive, and the most widely used to screen specimens. The performance of the LA Rotagen (Biokit S.A., Barcelona, Spain) was evaluated for rotavirus detection infecal samples of outpatients with acute gastroenteritis. This assay was compared with the enzyme immunoassay (EIA) EIARA (Bio-Manguinhos, Rio de Janeiro, Brazil). From January to October 2000, 285 fecal specimens were analyzed. Forty-four samples (15.4%) were reactive, 214 (75.4%) were nonreactive, and 27 (9.5%) were indeterminate by LA. All LA-positive samples were positive by EIA, and 2 LA-negative samples were positive by EIA. Of specimens indeterminate by LA, 67% were positive by EIA. The sensitivity, specificity, and accuracy of LA were 69%, 100%, and 93%, respectively. These results indicate that assay is as sensitive and specific as the EIA, and it could be applied on a large scale for screening stool specimens in suspected rotavirus diarrhea. However, the indeterminate results must be confirmed by other methods, such as EIA.     

Consensus sequence-based scheme for epidemiological typing of clinical and environmental isolates of Legionella pneumophila

A previously described sequence-based epidemiological typing method for clinical and environmental isolates of Legionella pneumophila serogroup 1 was extended by the investigation of three additional gene targets and modification of one of the previous targets. Excellent typeability, reproducibility, and epidemiological concordance were determined for isolates belonging to both serogroup 1 and the other serogroups investigated. Gene fragments were amplified from genomic DNA, and PCR amplicons were sequenced by using forward and reverse primers. Consensus sequences are entered into an online database, which allows the assignment of individual allele numbers. The resulting sequence-based type or allelic profile comprises a string of the individual allele numbers separated by commas, e.g., 1,4,3,1,1,1, in a predetermined order, i.e., flaA, pilE, asd, mip, mompS, and proA. The index of discrimination (D) obtained with these six loci was calculated following analysis of a panel of 79 unrelated clinical isolates. A D value of > 0.94 was obtained, and this value appears to be sufficient for use in the epidemiological investigation of outbreaks caused by L. pneumophila. The D value rose to 0.98 when the results of the analysis were combined with those of monoclonal antibody subgrouping. Sequence-based typing of L. pneumophila is epidemiologically concordant and discriminatory, and the data are easily transportable. This consensus method will assist in the epidemiological investigation of L. pneumophila infections, especially travel-associated cases, by which it will allow a rapid comparison of isolates obtained in more than one country.     

Qualitative difference between the cytotoxic T lymphocyte responses to melanocyte antigens in melanoma and vitiligo

Vitiligo is a skin disorder characterized by depigmented macules secondary to melanocyte loss. An unusual facet is its relation to melanoma: cytotoxic T lymphocytes directed to melanocyte antigens are found in both conditions and imply a breakdown of tolerance, yet the resulting immune reaction is the opposite. The mechanisms at the basis of these opposite effects are not known. Here, we performed a direct comparison of whole melanocyte-specific T cell populations in the two diseases. We demonstrate that neither precursor frequencies of Melan-A/MART-1-specific T lymphocytes nor their status of activation differ significantly. However, by using a tetramer-based T cell receptor down-regulation assay, we documented a higher affinity of vitiligo T cells. We calculated that the peptide concentration required for 50% of maximal receptor down-regulation differed by 6.5-fold between the two diseases. Moreover, only vitiligo T cells were capable of efficient receptor down-regulation and IFN-gamma production in response to HLA-matched melanoma cells, suggesting that this difference in receptor affinity is physiologically relevant. The differences in receptor affinity and tumor reactivity were confirmed by analyzing Melan-A/MART-1-specific clones established from the two diseases. Our results suggest that the quality, and not the quantity, of the melanocyte-specific cytotoxic responses differs between the two pathologies.     

A new method to assess oxidative stress in ART cycles

The role of oxidative stress (OS) in female reproduction is an understudied area for investigation. The aim of the study was to assess reactive oxygen species (ROS) levels both in follicular fluid (FF) and in serum samples of women undergoing IVF and to relate them to clinical outcomes. A total of 56 women were enrolled. From each patient a sample of serum and FF were collected at oocyte retrieval day and analyzed for OS, by measuring a class of reactive oxygen metabolites (ROMs) (dROMs test) and for biological anti-oxidant potential levels (BAP test). The data analyzed in serum and in FF were related to pregnancy outcomes. There was no significant relationship between d-ROMs and BAP levels in serum or FF GROUP A and B and the clinical parameters of prognosis of women: age, number of oocytes retrieved number of oocytes methaphase II, FSH, fertilization rate and cleavage rate, number of embryos transferred and embryo score. There was a positive association between systemic levels of OS measured in serum GROUP A and pregnancy outcomes (p?=?0.007) suggesting that the evaluation of OS in FF needs more investigation about markers in follicular microenvironment in order to predict IVF success.     

Favorable outcome of primary liver transplantation in children with cirrhosis and hepatocellular carcinoma

The outcome of HCC after transplantation (OLT) in children is not well known. Unfavorable features based on adult reports may lead to contraindicate OLT even in children. We reviewed a cohort of children with cirrhosis and HCC to evaluate their outcome after primary transplantation. We considered children with cirrhosis and HCC who had a primary OLT. We retrospectively recorded demographic, medical and surgical features, and MC as predictors of outcome. Among 456 children transplanted in the last 15 yr, 10 (2%), median age at diagnosis 1.8 yr (range 0.5-7.2), had HCC in biliary atresia (3), BSEP deficiency (3), tyrosinemia type 1 (2), complications of choledocal cyst and glycogen storage disease type IV (1 each). At HCC discovery, median AFP was 2322 ng/mL (3-35,000), high or rising in 9/10 patients. Six patients were outside the MC. Median time on the waiting list was 38 days (1-152). Two patients died from early complications of OLT. In the other eight patients, there was no tumor recurrence after a median follow-up of four yr. Children with cirrhosis may develop HCC at a very young age. The outcome appears excellent even outside MC. Primary liver transplantation is advisable for children with cirrhosis, HCC, and no extrahepatic disease.     

Association Between Left Atrial Size and Measures of Adiposity Among Normal Adolescent Boys

Obesity (OB) in adults is associated with insulin resistance, hypertension, and left atrial (LA) enlargement. This study aimed to determine the association between LA size and (1) different components of the metabolic syndrome (body mass index [BMI], waist circumference [WC], insulin levels, lipid levels, and blood pressure), and (2) left ventricular (LV) diameters and diastolic function. Data were collected cross-sectionally from 142 healthy adolescent boys age 16.8 ± 2.0 years in 2009. Measurements of BMI, WC, blood pressure, lipid profile, and insulin were performed. Mode M, two-dimensional Doppler echocardiography was performed. Measurements of LA area, LV end diastolic diameter (EDD), end systolic diameter (ESD), posterior wall, interventricular septum (IVS), and shortening fraction were performed. Tisular Doppler of the diastolic mitral annular E wave (DTE) and A wave (DTA) and the ratio of maximal early diastolic filling wave velocity to maximal early diastolic myocardial velocity (E/e′) were recorded. The study group included 38 OB boys (26.8%) and 32 overweight boys (22.5%). Significant univariate association was found between LA area and BMI (r = 0.61), WC (r = 0.56), systolic blood pressure (r = 0.21), insulinemia (r = 0.28), high-density lipoprotein-cholesterol (HDL-C) (r = –0.24), triglycerides (r = 0.20), EDD (r = 0.25), LV posterior wall (r = 0.25), IVS (r = 0.25), DTE (r = 0.27), DTA (r = 0.30), and E/e′ (r = –0.28). Multiple linear regression analysis showed that LA area was associated with BMI (B = 0.61; R ² = 0.47) adjusted for confounding variables. In adolescents, BMI and WC were significantly associated with LA, suggesting that OB could be associated with LA enlargement as early as adolescence.     

Congenital posterior cervical spine malformation due to biallelic c.240‐4T>G RIPPLY2 variant: A discrete entity

The clinical and radiological spectrum of spondylocostal dysostosis syndromes encompasses distinctive costo‐vertebral anomalies. RIPPLY2 biallelic pathogenic variants were described in two distinct cervical spine malformation syndromes: Klippel–Feil syndrome and posterior cervical spine malformation. RIPPLY2 is involved in the determination of rostro‐caudal polarity and somite patterning during development. To date, only four cases have been reported. The current report aims at further delineating the posterior malformation in three new patients. Three patients from two unrelated families underwent clinical and radiological examination through X‐ray, 3D computed tomography and brain magnetic resonance imaging. After informed consent was obtained, family‐based whole exome sequencing (WES) was performed. Complex vertebral segmentation defects in the cervico‐thoracic spine were observed in all patients. WES led to the identification of the homozygous splicing variant c.240‐4T>G in all subjects. This variant is predicted to result in aberrant splicing of Exon 4. The current report highlights a subtype of cervical spine malformation with major atlo‐axoidal malformation compromising spinal cord integrity. This distinctive mutation‐specific pattern of malformation differs from Klippel–Feil syndrome and broadens the current classification, defining a sub‐type of RIPPLY2‐related skeletal disorder. Of note, the phenotype of one patient overlaps with oculo‐auriculo‐vertebral spectrum disorder.     

VACTERL/caudal regression/Currarino syndrome-like malformations in mice with mutation in the proprotein convertase Pcsk5

We have identified an ethylnitrosourea (ENU)-induced recessive mouse mutation (Vcc) with a pleiotropic phenotype that includes cardiac, tracheoesophageal, anorectal, anteroposterior patterning defects, exomphalos, hindlimb hypoplasia, a presacral mass, renal and palatal agenesis, and pulmonary hypoplasia. It results from a C470R mutation in the proprotein convertase PCSK5 (PC5/6). Compound mutants (Pcsk5(Vcc/null)) completely recapitulate the Pcsk5(Vcc/Vcc) phenotype, as does an epiblast-specific conditional deletion of Pcsk5. The C470R mutation ablates a disulfide bond in the P domain, and blocks export from the endoplasmic reticulum and proprotein convertase activity. We show that GDF11 is cleaved and activated by PCSK5A, but not by PCSK5A-C470R, and that Gdf11-deficient embryos, in addition to having anteroposterior patterning defects and renal and palatal agenesis, also have a presacral mass, anorectal malformation, and exomphalos. Pcsk5 mutation results in abnormal expression of several paralogous Hox genes (Hoxa, Hoxc, and Hoxd), and of Mnx1 (Hlxb9). These include known Gdf11 targets, and are necessary for caudal embryo development. We identified nonsynonymous mutations in PCSK5 in patients with VACTERL (vertebral, anorectal, cardiac, tracheoesophageal, renal, limb malformation OMIM 192350) and caudal regression syndrome, the phenotypic features of which resemble the mouse mutation. We propose that Pcsk5, at least in part via GDF11, coordinately regulates caudal Hox paralogs, to control anteroposterior patterning, nephrogenesis, skeletal, and anorectal development.     

Thymosin alpha 1: A comprehensive review of the literature

Thymosin alpha 1 is a peptide naturally occurring in the thymus that has long been recognized for modifying, enhancing, and restoring immune function. Thymosin alpha 1 has been utilized in the treatment of immunocompromised states and malignancies, as an enhancer of vaccine response, and as a means of curbing morbidity and mortality in sepsis and numerous infections. Studies have postulated that thymosin alpha 1 could help improve the outcome in severely ill corona virus disease 2019 patients by repairing damage caused by overactivation of lymphocytic immunity and how thymosin alpha 1 could prevent the excessive activation of T cells. In this review, we discuss key literature on the background knowledge and current clinical uses of thymosin alpha 1. Considering the known biochemical properties including antibacterial and antiviral properties, time-honored applications, and the new promising findings regarding the use of thymosin, we believe that thymosin alpha 1 deserves further investigation into its antiviral properties and possible repurposing as a treatment against severe acute respiratory syndrome coronavirus-2.