Chlamydophila abortus (Chlamydia psittaci serotype 1) clearance is associated with the early recruitment of neutrophils and CD8(+)T cells in a mouse model

The immune mechanisms in response to Chlamydophila abortus (Chlamydia psittaci serotype 1) infection were studied in C57BL/6 and CBA mice. The infection was monitored and the following aspects of the immune response were evaluated: the nature of the leucocyte infiltrate in the liver, the percentages of polymorphonuclear neutrophils (PMNs), macrophages and lymphocytes in the spleen, and the concentrations of cytokines in serum. In addition, the serum concentrations of IgG1 and IgG2a were determined. Both mouse strains showed a Th1-like immune response, with high concentrations of IFN-gamma and minimal levels of IL-4; however, C57 mice differed from CBA mice in showing milder clinical signs and earlier resolution of infection. The greater ability of C57 mice than CBA mice to eliminate chlamydophilae was related to the establishment of an earlier innate immunity, based on a more pronounced PMN response, and on a greater presence of CD8(+)T cells.     

Hydrophilic polymers derived from vitamin E

Vitamin E containing copolymers for biomedical applications was obtained by copolymerization reaction of vitamin E methacrylate (VEMA) with 2-hydroxyethyl methacrylate (HEMA), N,N-dimethyl acrylamide (DMA) or vinyl pyrrolidone (VP), in different experiments. High molecular weight copolymers prepared by free radical reactions initiated by azobisisobutironitrilo, AIBN, present a random distribution of vitamin E derivatives along the macromolecular chains, and the average composition depends on the initial composition of the reaction medium. The relative flexibility of the polymeric systems was analyzed measuring the glass transition temperature of copolymeric sequences and that of the pure alternating diad (Tg12) obtained by the application of the treatments proposed by Johnston and Barton to all the systems. Tg12 was higher than the average T of both homopolymers (Tg) for the VEMA-HEMA system, Tg12 was lower than Tg for the VEMA-DMA system and Tg12 was similar to Tg for the VEMA-VP system. VEMA-HEMA copolymers gave rise to hydrogels in water, acidic and alkaline media. VEMA-DMA copolymers gave rise to hydrogels in acidic medium and dissolved in water and alkaline medium. VEMA-VP copolymers were soluble in all media. The swelling of all the hydrogels fit a second order kinetics. A VEMA-HEMA hydrogel was selected for in vivo experiments in order to study the influence of vitamin E on the regeneration process of Achilles tendon. The polymeric derivatives of vitamin E stimulated the regenerative process as a consequence of the antiaging effect in the local area of application.     

Evolution of MHC-G in humans and primates based on three new 3'UT polymorphisms

MHC-G is a class Ib (non-classical) major histocompatibility complex (MHC) whose functional and evolutionary characteristics are still under scrutiny. The study of noncoding sequences in the MHC genes may provide important phylogenetic information. In this work we have sequenced the MHC-G exon 8, which encodes for the 3'UT region, in different species of primates. It has been shown that: (1) a previously described 14 base pair (bp) deletion polymorphism is human-specific and the HLA-G alleles may be classified according to its absence or presence; (2) another newly described 3 bp deletion/insertion polymorphism is also human-specific; and (3) another newly described 51 bp deletion polymorphism is common to Pongidae and humans, but is not found in other primates belonging to the Cercopithecinae family. A hypothesis on the evolutionary pathway of this gene is put forward in the light of these findings.     

Changed accumbal responsiveness to alcohol in rats pre-treated with nicotine or the cannabinoid receptor agonist WIN 55,212-2

Alcohol, nicotine, and cannabinoid acutely increase the activity of the mesolimbic dopamine (DA) pathway. Although polysubstance consumption is a common pattern of abuse in humans, little is known about dopamine release following pre-exposure to these drugs. The purpose of this study was to test whether alcohol-induced dopamine release into the nucleus accumbens (NAc) shell is modified by different pre-treatments: water (i.g.), alcohol (1 g/kg, i.g.), nicotine (0.4 mg/kg, s.c.), and WIN 55,212-2 (1 mg/kg, s.c.). Male Wistar rats were treated (i.g.) for 14 days with either water or alcohol. In the following 5 days rats were injected (s.c.) with vehicle, nicotine, or WIN 55,212-2. Finally, a cannula was surgically implanted into the NAc shell and alcohol-induced extracellular dopamine release was monitored in freely moving rats. Alcohol (1 g/kg; i.g.) only increased the release of dopamine when animals were previously treated with water. This DA increase was markedly inhibited by (subchronic) treatment (5 days) with nicotine or WIN 55-212-2 as well as by previous (chronic) exposure to alcohol (14 days). These data demonstrate that pre-treatment with nicotine and the cannabinoid agonist WIN 55,212-2 is able to change the sensitivity of the NAc shell in response to a moderate dose of alcohol. Therefore, cannabinoid and nicotine exposure may have important implications on the rewarding effects of alcohol, because these drugs lead to long-lasting changes in accumbal dopamine transmission.     

Comparison of the allergenicity and Ole e 1 content of 6 varieties of Olea europaea pollen collected during 5 consecutive years.

BACKGROUND: Numerous varieties of Olea europaea have been described in Mediterranean countries. OBJECTIVE: To investigate the immunochemical characteristics of 6 varieties of Olea europaea collected during 5 consecutive years. METHODS: The varieties Carrasquefio, Manzanillo, Acebuche (wild olive), Hojiblanco, Picual, and Nevado were analyzed. Pollen samples from each variety were collected for 5 consecutive years from the same cultivars by trained personnel. The antigenic and allergenic profiles of these extracts were evaluated by means of sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot using the serum of 29 O. europaea-allergic individuals. Ole e 1 was measured using enzyme-linked immunosorbent assay and purified Ole e 1 and rabbit polyclonal antibodies. Allergenic potency was determined using enzyme-linked immunosorbent assay inhibition and is expressed in histamine equivalent prick units per gram of raw material. RESULTS: Hojiblanco and Acebuche had the lowest mean +/- SD Ole e 1 content in the 5 years (0.045 +/- 0.029 and 0.059 +/-0.031 microg/microg of freeze-dried material, respectively). The variety with the highest mean +/- SD Ole e 1 content was Picual (0.19 +/-0.075 microg/microg). Hojiblanco had the lowest total biological potency throughout the study. A positive correlation was obtained between rainfall in the winter months and total allergenicity of the 6 varieties. CONCLUSIONS: The different varieties of O. europaea pollen demonstrated great differences in allergenic potency and Ole e 1 content. These differences were maintained throughout the study, suggesting that they are due to genetic differences intrinsic to the varieties, although certain climatic effects may also play a role.     

Pre-test prediction models of BRCA1 or BRCA2 mutation in breast/ovarian families attending familial cancer clinics

Objective: To test whether statistical models developed to calculate pre-test probability of being a BRCA1/2 carrier can differentiate better between the breast/ovarian families to be referred to the DNA test laboratory.

Study design: A retrospective analysis was performed in 109 Spanish breast/ovarian families previously screened for germline mutations in both the BRCA1 and BRCA2 genes. Four easy to use logistic regression models originally developed in Spanish (HCSC model), Dutch (LUMC model), Finnish (HUCH model), and North American (U Penn model) families and one model based on empirical data of Frank 2002 were tested. A risk counsellor was asked to assign a subjective pre-test probability for each family. Sensitivity, specificity, negative and positive predictive values, and areas under receiver operator characteristics (ROC) curves were calculated in each case. Correlation between predicted probability and mutation prevalence was tested. All statistical tests were two sided.

Results: Overall, the models performed well, improving the performances of a genetic counsellor. The median ROC curve area was 0.80 (range 0.77-0.82). At 100% sensitivity, the median specificity was 30% (range 25-33%). At 92% sensitivity, the median specificity was 42% (range 33.3-54.2%) and the median negative predictive value was 93% (range 89.7-98%). BRCA1 families tended to score higher risk than BRCA2 families in all models tested.

Conclusions: All models increased the discrimination power of an experienced risk counsellor, suggesting that their use is valuable in the context of clinical counselling and genetic testing to optimise selection of patients for screening and allowing for more focused management. Models developed in different ethnic populations performed similarly well in a Spanish series of families, suggesting that models targeted to specific populations may not be necessary in all cases. Carrier probability as predicted by the models is consistent with actual prevalence, although in general models tend to underestimate it. Our study suggests that these models may perform differently in populations with a high prevalence of BRCA2 mutations.

     

IgH, TCR-gamma, and TCR-beta gene rearrangement in 80 B- and T-cell non-Hodgkin's lymphomas: study of the association between proliferation and the so-called "aberrant" patterns.

The current study analyzes the rearrangement pattern of immunoglobulin H (IgH), T-cell receptor (TCR)-gamma, and TCR-beta genes in a group of 80 non-Hodgkin's lymphomas (NHL) of different histologic subtypes (43 B-cell and 37 T-cell types). The sensitivity and specificity provided by polymerase chain reaction amplification of these loci are evaluated. The association between the proliferation index and the presence of the so-called "aberrant" or "dual" rearrangements is also considered. Ninety-one percent of B-cell NHL showed IgH gene monoclonality, and 21% also exhibited a monoclonal pattern in one of the TCR genes. Among T-cell NHL, the sensitivity of the study was 65% for the TCR-gamma gene and 46% for the TCR-beta gene. The total sensitivity was 76%, amplifying both loci. IgH gene aberrant rearrangements were observed in 16% of T-cell neoplasms. A substantial percentage of dual rearrangements were detected in precursor and mature B- and T-cell NHL. B-cell NHL showed a tendency toward higher values of proliferation when aberrant rearrangements were present; however, this trend was not significant. Furthermore, in the case of T-cell NHL there was a significant negative association between these two variables.     

Evolution of the influenza virus neuraminidase gene during drift of the N2 subtype

The complete genetic information for the neuraminidase (NA) gene of influenza virus A/Bangkok/1/79 has been cloned by in vitro synthesis of dsDNA, insertion into pBR322 plasmid, and transformation of Escherichia coli. The nucleotide sequence of the NA gene has been determined by the Maxam and Gilbert method. It is 1466 nucleotides long and contains a single open reading frame with a coding capacity for 469 amino acids. When compared to the NA genes of the N2 strains A/Victoria/3/75, A/Udorn/72, A/NT/60/68, and A/RI/5-/57, 90% of the nucleotide positions and 87% of the amino acid positions remained invariant. Forty-two nucleotide changes and 14 amino acid changes accumulated in the period 1975-1979, but the general structure of the protein appeared to remain constant.