Short communication: Bovine milk sampling efficiency for pregnancy-associated glycoproteins (PAG) detection test

Two experiments were conducted to verify whether the time of day at which a milk sample is collected and the possible carryover in the milking system may affect pregnancy-associated glycoproteins (PAG) levels and, consequently, the pregnancy test results in dairy cows. In experiment one, we evaluated the effect of time of day at which the milk sample is collected from 51 cows. In experiment two, which evaluated the possible occurrence of carryover in the milk meter milking system, milk samples from 94 cows belonging to two different farms were used. The samples were subjected to pregnancy test using ELISA methodology to measure PAG concentrations and to classify the samples as positive (pregnant), negative (nonpregnant), or suspicious (recheck). We found that the time of milking did not affect the PAG levels. As to the occurrence of carryover in the milk meter, the PAG levels of the samples collected from Farm-2 were heavily influenced by a carryover effect compared with the samples from Farm-1. Thus, milk samples submitted to a pregnancy test can be collected during the morning or the evening milking. When the sample is collected from the milk meters, periodic equipment maintenance should be noted, including whether the milk meter is totally drained between different animals’ milking and equipment cleaning between milking is performed correctly to minimize the occurrence of carryover, thereby avoiding the effect on PAG levels and, consequently, the pregnancy test results. Therefore, a single milk sample can be used for both milk quality tests and pregnancy test

The Cellular Prion Protein Interacts with the Tissue Non-Specific Alkaline Phosphatase in Membrane Microdomains of Bioaminergic Neuronal Cells

BACKGROUND: The cellular prion protein, PrP(C), is GPI anchored and abundant in lipid rafts. The absolute requirement of PrP(C) in neurodegeneration associated to prion diseases is well established. However, the function of this ubiquitous protein is still puzzling. Our previous work using the 1C11 neuronal model, provided evidence that PrP(C) acts as a cell surface receptor. Besides a ubiquitous signaling function of PrP(C), we have described a neuronal specificity pointing to a role of PrP(C) in neuronal homeostasis. 1C11 cells, upon appropriate induction, engage into neuronal differentiation programs, giving rise either to serotonergic (1C11(5-HT)) or noradrenergic (1C11(NE)) derivatives. METHODOLOGY/PRINCIPAL FINDINGS: The neuronal specificity of PrP(C) signaling prompted us to search for PrP(C) partners in 1C11-derived bioaminergic neuronal cells. We show here by immunoprecipitation an association of PrP(C) with an 80 kDa protein identified by mass spectrometry as the tissue non-specific alkaline phosphatase (TNAP). This interaction occurs in lipid rafts and is restricted to 1C11-derived neuronal progenies. Our data indicate that TNAP is implemented during the differentiation programs of 1C11(5-HT) and 1C11(NE) cells and is active at their cell surface. Noteworthy, TNAP may contribute to the regulation of serotonin or catecholamine synthesis in 1C11(5-HT) and 1C11(NE) bioaminergic cells by controlling pyridoxal phosphate levels. Finally, TNAP activity is shown to modulate the phosphorylation status of laminin and thereby its interaction with PrP. CONCLUSION/SIGNIFICANCE: The identification of a novel PrP(C) partner in lipid rafts of neuronal cells favors the idea of a role of PrP in multiple functions. Because PrP(C) and laminin functionally interact to support neuronal differentiation and memory consolidation, our findings introduce TNAP as a functional protagonist in the PrP(C)-laminin interplay. The partnership between TNAP and PrP(C) in neuronal cells may provide new clues as to the neurospecificity of PrP(C) function

¿Es necesario investigar anticuerpos IgM contra el virus de la hepatitis A cuando el enzimograma hepático es normal? Is it necessary to investigate anti-hepatitis A virus (HAV) IgM antibodies when the hepatic enzymogram is normal?

La hepatitis por virus A (VHA) es la más frecuente de las hepatitis virales en el mundo, especialmente en los países subdesarrollados. Donde esta enfermedad es endémica, se suelen realizar un gran número de estudios de laboratorio para confirmarla. El objetivo del presente trabajo fue evaluar la utilidad de investigar anticuerpos IgM anti hepatitis A (IgM anti-VHA) para el diagnóstico de la VHA en pacientes con niveles séricos normales de aspartato y alanina aminotransferasas (AST/ALT). Todos los pacientes que concurrieron al laboratorio con solicitud de enzimograma hepático y anticuerpos IgM anti-VHA durante el período octubre 2005-marzo 2006 fueron evaluados en este estudio. Los datos clínicos más frecuentes fueron presunción de hepatitis e ictericia (27,5 y 12,7%). La determinación de IgM anti-VHA se realizó por ensayo inmunoenzimático de micropartículas (MEIA); la de enzimas hepáticas en un multianalizador. De los 158 pacientes estudiados, 84 tenían valores elevados de AST/ALT; dentro de este grupo, el 82% fue reactivo para IgM anti-VHA. Los 74 pacientes restantes mostraron niveles normales de AST/ALT y solo 7 de ellos, bajo control de evolución por VHA ya confirmada, fueron reactivos para IgM anti-VHA. El 49% de los pacientes IgM anti-VHA reactivos correspondió a menores de 10 años. De acuerdo con estas observaciones, sugerimos que los estudios de laboratorio para confirmar infección aguda por VHA deberían realizarse en forma secuencial, ya que es innecesaria la determinación de anticuerpos IgM anti-VHA cuando las aminotransferasas séricas son normales.Type A viral Hepatitis (HAV) is the most frequent viral hepatitis around the world, especially in low income countries. In order to confirm this disease, a lot of laboratory tests are annually carried out where HAV is endemic. Our objective was to establish the utility of investigating anti-hepatitis A virus (HAV) IgM antibodies for HAV diagnosis in patients with normal levels of serum aspartate and alanine aminotransferases (AST/ALT). All patients (n = 158) received in the laboratory requesting a hepatic enzymograme and anti-HAV IgM were evaluated in a prospective study between October 2005 and March 2006. Anti-HAV IgM assays were carried out by microparticle enzyme immunoassay (MEIA). The quantification of hepatic enzymes was made in a multianalyzer. The most frequent clinical data were: presumption of hepatitis and jaundice (27.5 and 12.7%). Eighty four of the 158 patients (53%) showed elevated values of ALT and AST, whereas 69 patients in this group (82%) were anti-Hav IgM reactive. The remaining 74 patients (47%) showed normal levels of AST/ALT and none of them were anti-HAV IgM reactive, except 7, who were on control of a confirmed HAV infection. Of the anti-HAV IgM reactive group of patientss, 49% were children under 10 years of age. Laboratory HAV confirmatory tests would have to be made in sequential form, the determination of anti-HAV IgM antibodies being unnecessary when normal values of serum aminotransferases are observed