Ex vivo analysis of human antigen-specific CD8+ T-cell responses: quality assessment of fluorescent HLA-A2 multimer and interferon-gamma ELISPOT assays for patient immune monitoring.

The authors developed a standardized approach for immune monitoring of antigen-specific CD8+ T cells within peripheral blood lymphocytes (PBLs) that combines direct ex vivo analysis of Melan-A/MART-1 and influenza-specific CD8+ T cells with HLA-A2/peptide multimers and interferon-gamma ELISPOT assays. Here the authors assessed the quality of results obtained with 180 PBLs from healthy donors and melanoma patients. Reproducibility of the multimer assay was good (average of 15% variation). In the absence of in vivo antigen-specific T-cell responses, physiologic fluctuations of multimer-positive T cells was low, with variation coefficients of 20% for Melan-A and 28% for influenza-specific T cells. In contrast, patients with vaccination-induced T-cell responses had significantly increased T-cell frequencies clearly exceeding physiologic fluctuations. Comparable results were obtained with ELISPOT assays. In conclusion, this approach is well suited to assess T-cell responses as biologic endpoints in clinical vaccine studies.

Absence of snapshot memory of the target view interferes with place navigation learning by rats in the water maze

Contribution of visual and nonvisual mechanisms to spatial behavior of rats in the Morris water maze was studied with a computerized infrared tracking system, which switched off the room lights when the subject entered the inner circular area of the pool with an escape platform. Naive rats trained under light-dark conditions (L-D) found the escape platform more slowly than rats trained in permanent light (L). After group members were swapped, the L-pretrained rats found under L-D conditions the same target faster and eventually approached latencies attained during L navigation. Performance of L-D-trained rats deteriorated in permanent darkness (D) but improved with continued D training. Thus L-D navigation improves gradually by procedural learning (extrapolation of the start-target azimuth into the zero-visibility zone) but remains impaired by lack of immediate visual feedback rather than by absence of the snapshot memory of the target view.

Discriminant analysis of skull morphometric characters in Apodemus sylvaticus, A-flavicollis, and A-alpicola (Mammalia; Rodentia) from the Alps

A total of 108 Apodemus skulls from Switzerland, Austria, Italy, France and Germany was studied to determine morphological characteristics useful in identifying individuals as Apodemus sylvaticus (Linnaeus, 1758), A. flavicollis (Melchior, 1834) or A. alpicola Heinrich, 1952. The original assignment of the samples to the three species was based on molar cusp morphology, body proportions, pelage coloration, and allozyme analysis. The 24 measured cranial characters used together accurately discriminated between the three species and correctly classified 100% of the individuals to species. A stepwise discriminant function analysis showed that 6 cranial characters are sufficient to differentiate between the three species, with a correct classification above 97%. Fisher's linear discriminant function coefficients can be used directly for classification of unknown specimens.

Puhdasta puhetta?

Vastine Osmo Nikkilän arvosteluun Suomen sanojen alkuperät laahaamisesta pööveliin // Virittäjä Vol. 101 (1997) : 2, s. 291-308

High specificity of line-immunoassay based algorithms for recent HIV-1 infection independent of viral subtype and stage of disease.

ABSTRACT: BACKGROUND: Serologic testing algorithms for recent HIV seroconversion (STARHS) provide important information for HIV surveillance. We have shown that a patient's antibody reaction in a confirmatory line immunoassay (INNO-LIATM HIV I/II Score, Innogenetics) provides information on the duration of infection. Here, we sought to further investigate the diagnostic specificity of various Inno-Lia algorithms and to identify factors affecting it. METHODS: Plasma samples of 714 selected patients of the Swiss HIV Cohort Study infected for longer than 12 months and representing all viral clades and stages of chronic HIV-1 infection were tested blindly by Inno-Lia and classified as either incident (up to 12 m) or older infection by 24 different algorithms. Of the total, 524 patients received HAART, 308 had HIV-1 RNA below 50 copies/mL, and 620 were infected by a HIV-1 non-B clade. Using logistic regression analysis we evaluated factors that might affect the specificity of these algorithms. RESULTS: HIV-1 RNA <50 copies/mL was associated with significantly lower reactivity to all five HIV-1 antigens of the Inno-Lia and impaired specificity of most algorithms. Among 412 patients either untreated or with HIV-1 RNA ≥50 copies/mL despite HAART, the median specificity of the algorithms was 96.5% (range 92.0-100%). The only factor that significantly promoted false-incident results in this group was age, with false-incident results increasing by a few percent per additional year. HIV-1 clade, HIV-1 RNA, CD4 percentage, sex, disease stage, and testing modalities exhibited no significance. Results were similar among 190 untreated patients. CONCLUSIONS: The specificity of most Inno-Lia algorithms was high and not affected by HIV-1 variability, advanced disease and other factors promoting false-recent results in other STARHS. Specificity should be good in any group of untreated HIV-1 patients.

Epidemiology of uveitis in Switzerland.

During the period from January 1990 to December 1993, 558 new patients (250 female and 308 male, mean age 44 years; range 5-92) were seen at the Uveitis Clinic of the Hopital Jules Gonin. These 558 patients (740 eyes) were subdivided into anterior uveitis (343 patients-61%), intermediate uveitis (57 patients-10%), posterior uveitis (118 patients-21 %) and panuveitis (40 patients-7%). The incidence of uveitis for the referral area considered was calculated to be 17.5 per 100,000 inhabitants per year. A specific diagnosis was found in 386 cases (69%). The most frequently diagnosed entities were HLA-B27-associated acute anterior uveitis (89 cases-15.9%), uveitis associated with acute herpes zoster ophthalmicus (54 cases-9.7%), toxoplasmosis (53 cases-9.5%), sarcoidosis (33 cases-5.9%), typical pars planitis (31 cases-5.6%), Fuchs' heterochromic cyclitis (30 cases-5.4%), herpetic anterior uveitis (23 cases-4.1 %) and acute retinal necrosis (13 cases-2.3%). Incidence and distribution of most disease entities correspond to those of other European and American series.

Gene frequencies of plasminogen in Switzerland.

Plasminogen (PLG) polymorphism was studied by agarose gel electrophoresis and immunofixation in 308 unrelated individuals from Switzerland. The gene frequencies observed were: PLG 1 = 0.69, PLG 2 = 0.28, and rare alleles = 0.03.

Growth and differentiation of aggregating fetal brain cells in a serum-free defined medium.

Aggregating cultures of mechanically dissociated fetal brain cells provide an excellent system for neurobiological studies of cellular growth and differentiation, but, in common with almost all culture systems, they have the disadvantage that crude serum is required in the medium. Although several cell lines have either been adapted to serum-free conditions or grown normally in serum-free media supplemented with hormones, trace elements and defined serum components, this approach has never been applied to differentiating primary cells of the central nervous system. We now describe the successful cultivation of aggregating fetal rat brain cells in a chemically defined, serum-free medium.

New loci associated with birth weight identify genetic links between intrauterine growth and adult height and metabolism.

Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood. Previous genome-wide association studies of birth weight identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes and a second variant, near CCNL1, with no obvious link to adult traits. In an expanded genome-wide association meta-analysis and follow-up study of birth weight (of up to 69,308 individuals of European descent from 43 studies), we have now extended the number of loci associated at genome-wide significance to 7, accounting for a similar proportion of variance as maternal smoking. Five of the loci are known to be associated with other phenotypes: ADCY5 and CDKAL1 with type 2 diabetes, ADRB1 with adult blood pressure and HMGA2 and LCORL with adult height. Our findings highlight genetic links between fetal growth and postnatal growth and metabolism.