José Vidal

Pathogenic cysteine mutations affect progranulin function and production of mature granulins

J. Neurochem. (2010) 112, 1305–1315.

Further studies on the ELISA-spot technique: Its application to particulate antigens and a potential improvement in sensitivity

Applications of the ELISA-spot technique to particulate antigens (sheep erythrocytes and E. coli) are reported; sheep erythrocytes were used to ensure a rigorous comparison of the spot assay and the haemolytic plaque assay. The spot technique was also applied to soluble antigens (dextran and trinitrophenyl-lipopolysaccharide) to assess the putative occurrence of non-haemolytic antibodies. In most instances, the spot assay disclosed higher numbers of antibody-secreting cells than the plaque assay. An examination of the kinetics of spot formation demonstrated that spot development was most rapid during the first and second hours of enzyme activity and slowed thereafter, although the numbers of spots at 16 h were higher than those at 2 h. To shorten the assay time a redox reaction (which yields an insoluble formazan) was coupled to the enzymatic reaction. In duplicate assays, this improved technique gave larger numbers of spots in a shorter time, than the conventional assay.

Coupling redox and enzymic reactions improves the sensitivity of the ELISA-spot assay.

A method is described to increase the sensitivity of the conventional bromo-chloro-indolyl-phosphate ELISA-spot assay. The method is based on the addition of nitro blue tetrazolium to the substrate: the hydrogen ions released during the conversion of indoxyl to indigo, reduce the tetrazolium salt to insoluble diformazan. In this paper, the nitro blue tetrazolium assay is shown (a) to be more sensitive and faster than the bromo-chloro-indolyl-phosphate assay, and (b) to disclose precisely those areas where antibody secretion has occurred.

Bases anatomopatológicas de la disfunción ventricular latente en diabéticos insulinodependientes

Introduccion y objetivos La historia natural dela miocardiopatia diabetica no esta bien definida,debido principalmente a la comun asociacion conenfermedad coronaria e hipertension arterial. Dadoque estas dos entidades son infrecuentes en los pacientesjovenes, estos constituyen un modelo adecuadopara el estudio de la miocardiopatia diabeticaen sus fases incipientes. Pacientes y metodos Se estudiaron 33 pacientesafectados de diabetes mellitus tipo I sin antecedentesde hipertension arterial ni enfermedad coronaria.Su edad media era de 28 ± 8 anos (rango, 18-46anos) y 14 eran varones. Resultados En el ecocardiograma se observo unventriculo izquierdo de tamano normal y sin anomaliasde la motilidad segmentaria, excepto en uncaso. En la ventriculografia isotopica se detectouna fraccion de eyeccion basal del 56,5 ± 6,6% queaumento al 63 ± 7,4% (p Conclusiones La disfuncion ventricular latentees un hallazgo frecuente en los pacientes diabeticosjovenes asintomaticos, y esta no es secundaria aaterosclerosis coronaria ni a enfermedad de pequenovaso. En este grupo de pacientes las anomaliashistologicas son constantes y se manifiestan por fibrosisintersticial, hipertrofia celular, miocitolisis ydepositos lipidicos.

Association of the antibody response to hemocyanin with behavior in mice bred for high or low antibody responsiveness

Researchers attempted to find a genetic correlation between the antibody response and some behaviors by comparing the behavioral profile of good antibody-producing mice (Biozzis H mice) with that of bad antibody producers (Biozzis L mice). The behavioral tests used were 2 open fields, a light-darkness test, and reaction to capture; the antigen was keyhole limpet hemocyanin, and blood levels of immunoglobulin (Classes IgM and IgG) antibodies to hemocyanin were measured by diffusion-in-gel-enzyme-linked immunosorbent assay. H and L mice differed in the magnitude of the antibody response (H > L), in reaction to capture (L > H), and in rearing in 1 of the open fields (L > H). Yet the level of IgM or IgG antibodies was uncorrelated with those behaviors in the (H x L) F2 hybrids and in outbred CD1 mice. Thus, the behavioral differences between H and L mice are not due to the antibody response genes but to other genes fixed during selection for antibody responsiveness.

The conditioned stimulus elicits taste aversion but not sickness behavior in conditioned mice.

Objectives: This article extends previous reports on (i) elicitation of taste aversion after pairing a flavored beverage (saccharin solution) with a disease-provoking microbial product (lipopolysaccharide, LPS, or polyinosinic:polycytidylic acid, poly I:C); (ii) elicitation of sickness behavior (assessed as diminished ingestion of water and food) by the conditioned stimulus, and (iii) development of tolerance to those microbial products. Methods: Mice of the CD1 strain were conditioned by pairing ingestion of 0.15% saccharin solution with injection of LPS (100 µg/mouse) or poly I:C (6 mg/kg). A few days later, some mice were offered saccharin solution and were injected with saline, whereas other mice were offered saccharin solution and were injected with the microbial product. Results: Regardless of the nature of the unconditioned stimulus (LPS or poly I:C), (i) taste aversion to saccharin ensued, (ii) tolerance ensued to sickness elicitation by a second administration of the microbial component, and (iii) saccharin taste did not evoke sickness. Conclusions: Symptoms of infectious sickness in the absence of infection are hardly explained by exposure to the conditioned stimulus.

Differences of nu / + and nu / nu mice in some behaviors reflecting temperament traits

The goal of this paper is to discover a pattern of consistent behavioral differences between athymic CD1 nu/nu mice and euthymic CD1 nu/+ ones. The following behaviors, thought to be correlates of temperament traits, were measured along 3 trials: ambulation, rear, and defecation in two open fields of varying light intensity, interaction time with a conspecific, and variables in the light-darkness test (time in the lit compartment, latency to leave the dark compartment, and number of crossings between compartments). Besides, weight and (IgM and IgG) antibodies to rat erythrocytes were measured. Relative to nu/nu mice, nu/+ mice were heavier, yielded much higher antibody responses, interacted more with a conspecific (the males, but not the females), and ambulated slightly more in the open fields, although the proportion of variance in the behaviors accounted for by the nude mutation was small (< 20%). Therefore, the nude mutation participated in the expression of the activity or extraversion traits.

Mice Do Not Develop Conditioned Taste Aversion because of Immunity Loss

Objectives: This study intends to test the generation of conditioned taste aversion and conditioned immunodepression by daily paired administration of saccharin solution with cyclophosphamide, 15 mg/kg, for 4 days. Methods: One group of male mice of the outbred CD1 strain drank 0.15% saccharin and received 1 injection of cyclophosphamide, 15 mg/kg, for 4 days (paired group), another group (unpaired group) received the same doses of saccharin and cyclophosphamide noncontingently, the third group (cy60) received saccharin paired with cyclophosphamide, 60 mg/kg, and the fourth group (placebo) received saccharin in the absence of cyclophosphamide. All mice were immunized with keyhole limpet hemocyanin (KLH), 0.2 mg, 1 day before the treatments. Results: Mice of the paired, unpaired and cy60 groups displayed a similarly decreased antibody response to KLH, but mice of the paired group did not develop an aversion to saccharin while mice of the cy60 group did. Besides, repeat presentation of saccharin to mice of the paired group did not alter their antibody response to ovalbumin compared with mice of the unpaired or placebo group. Conclusions: Taste aversion was not elicited in response to impaired immunity and the conditioned stimulus (saccharin) did not impair the antibody response.

Taste-Aversion Conditioning, But Not Immunosuppression Conditioning, Occurs Under Partial Water Deprivation

The authors investigated whether conditioned taste aversion and immunosuppression took place when water was available during conditioning and test protocols. The authors elicited taste-aversion conditioning and immunosuppression in outbred CD1-strain mice by pairing a conditioned stimulus (sucrose or saccharin solution) with an unconditioned stimulus (cyclophosphamide) that causes gastrointestinal upset and is immunosuppressive. The authors introduced a new conditioning protocol: 5 pairings of a saccharin solution with a low-dose injection of cyclophosphamide. Under these conditions, the authors generated conditioned aversion to saccharin but did not generate conditioned decrease of the antibody response. The authors conclude that taste-aversion conditioning, but not immunosuppression conditioning, occurred under partial water deprivation.

Antibody response and some behaviors as differential traits between two inbred strains of mice (C57BL/6 and BALB/C)

The goals of this research were to find out if the antibody response and some behaviors are differential traits for murine strains C57BL/6 and BALB/c and to study the influence of strain and isolation on both behavior and the antibody response. 21 C57BL/6 male mice and 28 BALB/c male mice were used; of those, 11 C57BL/6 and 16 BALB/c were kept isolated, and the remaining mice were housed 2 per cage. The tests were Open-fields 1, 2, and 3 (of varying light and sound stimulation), holeboard, light-darkness test, immunization with rat erythrocytes; in addition, the mice were weighed. The traits that best differentiated both strains (according to discriminant analysis) were weight, IgM primary response, and emotional behavior (ambulation, rearing, and defecation in stimulating open-fields). Social isolation (of adult mice) influenced emotional behavior, but not the antibody response.