Uterine and fetal asphyxia monitoring in parturient sows treated with oxytocin

Oxytocin is used to induce and control parturition, nevertheless, the increase of uterine contractions decreases blood flow and gaseous exchange through the womb predisposing to intra-partum mortality. The objective of the present study was to evaluate the effect of oxytocin on myometrial activity, fetal intrauterine hypoxia and postnatal asphyxia in sows during farrowing. Hybrid (n = 120) sows approaching the time of farrowing were randomly assigned in two groups of 60 animals each. Group I (G(1): control) was treated IM with saline solution and Group II (G(2)) was injected IM with oxytocin (1IU/6kg LW) as a single dose at birth of the first piglet. Both average number of myometrial contractions and intensity in G(2) were greater (P < 0.01) as compared with G(1). The mean of intra-partum stillbirths (IPS's) and those where fetal cardiac frequency (FCF) or heart beats, could not be detected after birth, were greater (P < 0.01) in G(2) as compared with G(1). The average decelerations of FCF known as dips II, which indicate severe hypoxia, was greater in G(2) (P < 0.01) as compared with that of G(1). There was a greater (P < 0.01) number of intra-partum stillbirths, stained with severe meconium in G(2) when compared with G(1). Oxytocin treatment increased (P < 0.01) the number of pigs born alive with ruptured umbilical cords and those with different grades of meconium staining on their skin. It was concluded that administration of oxytocin at the onset of parturition increased the myometrial activity, decreased fetal cardiac frequency, predisposed the rupture of umbilical cords and the degree of meconium staining, and increased intra-partum mortality.     

VariScan: Analysis of evolutionary patterns from large-scale DNA sequence polymorphism data

SUMMARY: VeriScan is a software package for the analysis of DNA sequence polymorphisms at the whole genome scale. Among other features, the software (1) can conduct many population genetic analyses; (2) incorporates a multiresolution wavelet transform-based method that allows capturing relevant information from DNA polymorphism data; (3) facilitates the visualization of the results in the most commonly used genome browsers.     

Continuous-flow/stopped-flow system for enzyme immunoassay using a rotating bioreactor: determination of Chagas disease

The high sensitivity that can be attained using an immunoassays coupled to a rotating bioreactor with electrochemical detection mediated by [Os(bpy)2Cl(pyCOOH)]Cl, has been verified for the detection of Trypanozoma cruzi (T. cruzi), This protozoan parasite causes Chagas disease, affecting more than 18 million people in central and south America. Antibodies in the serum sample are allowed to react immunologically with whole homogenates of the parasite as antigen that are immobilized on a rotating disk. The bound antibodies are quantified by a horseradish peroxidase (HRP) enzyme labeled second antibodies specific to human IgG in presence of hydrogen peroxide using an osmium complex [Os(bpy)2Cl(pyCOOH)]Cl as enzymatic mediators. The amperometric measurement performed at 0.00 V versus Ag/AgCl can be done within 2 min and the analysis time does not exceed 23 min. The calculated detection limits was 0.01 mIU ml(-1). Reproducibility assays were made using repetitive serum of 0.182 mIU ml(-1) T. cruzi specific antibody (measured as the activity of the correspondent anti-serum's enzyme conjugated); the percentage standard error was less than 5%. The amperometric immunoreactors showed significantly higher sensitivity and lower time consumed than the standard spectrophotometric detection ELISA method.     

Cloning and characterization of the phosphoglucomutase of Trypanosoma cruzi and functional complementation of a Saccharomyces cerevisiae PGM null mutant

Trypanosoma cruzi is the etiological agent of Chagas' disease, a chronic illness characterized by progressive cardiomyopathy and/or denervation of the digestive tract. The parasite surface is covered with glycoconjugates, such as mucin-type glycoproteins and glycoinositolphospholipids (GIPLs), whose glycans are rich in galactopyranose (Galp) and/or galactofuranose (Galf) residues. These molecules have been implicated in attachment of the parasite to and invasion of mammalian cells and in modulation of the host immune responses during infection. In T. cruzi, galactose (Gal) biosynthesis depends on the conversion of uridine diphosphate (UDP)-glucose (UDP-Glc) into UDP-Gal by an NAD-dependent reduction catalyzed by UDP-Gal 4-epimerase. Phosphoglucomutase (PGM) is a key enzyme in this metabolic pathway catalyzing the interconversion of Glc-6-phosphate (Glc-6-P) and Glc-1-P which is then converted into UDP-Glc. We here report the cloning of T. cruzi PGM, encoding T. cruzi PGM, and the heterologous expression of a functional enzyme in Saccharomyces cerevisiae. T. cruzi PGM is a single copy gene encoding a predicted protein sharing 61% amino acid identity with Leishmania major PGM and 43% with the yeast enzyme. The 59-trans-splicing site of PGM RNA was mapped to a region located at 18 base pairs upstream of the start codon. Expression of T. cruzi PGM in a S. cerevisiae null mutant-lacking genes encoding both isoforms of PGM (pgm1Delta/pgm2Delta) rescued the lethal phenotype induced upon cell growth on Gal as sole carbon source.     

Different approaches for assaying melanosome transfer

Many approaches have been tried to establish assays for melanosome transfer to keratinocytes. In this report, we describe and summarize various novel attempts to label melanosomes in search of a reliable, specific, reproducible and quantitative assay system. We tried to fluorescently label melanosomes by transfection of GFP-labeled melanosomal proteins and by incubation of melanocytes with fluorescent melanin intermediates or homologues. In most cases a weak cytoplasmic fluorescence was perceived, which was probably because of incorrect sorting or deficient incorporation of the fluorescent protein and different localization. We were able to label melanosomes via incorporation of 14C-thiouracil into melanin. Consequently, we tried to develop an assay to separate keratinocytes with transferred radioactivity from melanocytes after co-culture. Differential trypsinization and different magnetic bead separation techniques were tested with unsatisfactory results. An attempt was also made to incorporate fluorescent thiouracil, since this would allow cells to be separated by FACS. In conclusion, different methods to measure pigment transfer between donor melanocytes and acceptor keratinocytes were thoroughly examined. This information could give other researchers a head start in the search for a melanosome transfer assay with said qualities to better understand pigment transfer.     

Noncommutativity of eye rotations and the half-angle rule

In order to produce kinematically efficient behavior when dealing with the noncommutativity of rotations, the oculomotor system has developed strategies such as the half-angle rule. In this issue of Neuron, Ghasia and Angelaki demonstrate that during smooth pursuit eye movements the half-angle rule is implemented by the mechanical properties of the eye plant.     

Electrophoresis karyotype and chromosome-length polymorphism of Histoplasma capsulatum clinical isolates from Latin America

Intact chromosomes of 19 clinical isolates of Histoplasma capsulatum recently obtained in Argentina, Mexico and Guatemala and the laboratory reference strain G186B from Panama were analyzed using pulsed-field gel electrophoresis. Chromosomal banding patterns of the human isolates revealed 5-7 bands, ranging from 1.3 to 10 Mbp in size. Strain G186B showed five bands of approximately 1.1, 2.8, 3.3, 5.4 and 9.7 Mbp. Thirteen different electrokaryotypes were identified, indicating that the genome of H. capsulatum varies widely in nature, as observed previously in laboratory strains. No definite association was found between electrokaryotype and geographical or clinical source.     

Matrix gamma-carboxyglutamic acid protein (MGP) G-7A and T-138C gene polymorphisms in Indian (Mayo and Teenek) and Mestizo populations from Mexico

Matrix gamma-carboxyglutamic acid protein (MGP) genotypes (G-7A and T-138C) were determined in 266 individuals from three Mexican populations. Mexicans showed increased frequencies of the G-7A G allele and the G7-A GG genotype compared to Europeans. For the T-138C genotype, we found differences among the Mexicans. This study could help to define the significance of MGP polymorphisms as genetic markers in Amerindian populations.     

Molecular demonstration of SLC4A1 gene deletion in two Mexican patients with Southeast Asian ovalocytosis

We describe the finding of two Mexican patients with a specific 27-bp deletion in the solute carrier family 4 gene (SLC4A1delta27) (also known as the band 3 gene found on chromosome 17q21-q22), characteristic of Southeast Asian ovalocytosis (SAO). The patients were asymptomatic, and the initial diagnosis was made by microscopic observation of the presence of typical stomatocytic ovalocytes. The gene deletion was confirmed by PCR and DNA sequencing. Both patients were heterozygous for the deletion. One patient is from Tabasco state, in southeastern Mexico, a malaria-endemic zone. The other patient is from Mexico City, which is not a malaria-endemic area. Their families have no non-Mexican ancestors and their previous generations were born in Mexico. Both patients carry the HLA-B*3501 subtype, characteristic of Amerindians and Asian populations. Familial and HLA data led us to conclude that these two patients are the first report of SLC4A1delta27 in Amerindians. The nucleotide analysis showing a perfect match sequence between Southeast Asian and Mexican patients suggests, but does not prove, that the Mexican gene is not a de novo mutation. Instead, this gene might be the result of migration of individuals with Asian ancestry into the Mexican gene pool. We are looking for other families with the mutation to detect, by HLA analysis, the ancient ethnic origin of these patients.