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Site-specific genetic divergence in parallel hybrid zones suggests non-allopatric evolution of reproductive barriers

The evolution of reproductive isolation in the presence of gene flow is supported by theoretical models but rarely by data. Empirical support might be gained from studies of parallel hybrid zones between interbreeding taxa. We analysed gene flow over two hybrid zones separating ecotypes of Littorina saxatilis to test the expectation that neutral genetic markers will show site-specific differences

Comparison of the adsorption of o-phthalate on boehmite (gamma-AlOOH), aged gamma-Al2O3, and goethite (alpha-FeOOH)

This work is concerned with the adsorption of o-phthalate (1,2-benzenedicarboxylate) at the water-metal (hydr)oxide interface. Previously published infrared spectroscopic, potentiometric, and adsorption data characterizing the boehmite (gamma-AlOOH) system are compared with new data collected for o-phthalate adsorption on aged gamma-Al2O3 and goethite (alpha-FeOOH). The study focuses on identifyin

Assessment of beta-cell function during the oral glucose tolerance test by a minimal model of insulin secretion

Objective To characterise the performance of beta -cell during a standard oral glucose tolerance test (OGTT). Design Fifty-six subjects were studied. A minimal analogic model of beta -cell secretion during the OGTT was applied to all OGTTs (see below). The amount of insulin secreted over 120' in response to oral glucose (OGTT-ISR; Insulin Units 120'(-1) m(-2) BSA) and an index of beta -cell secret

Inflammatory markers in matched plasma and cerebrospinal fluid from patients with Alzheimer's disease.

It has been suggested that a number of molecules associated with inflammation are involved in the pathogenesis of Alzheimer's disease (AD). We measured the levels of alpha1-antichymotrypsin (ACT), alpha1-antitrypsin (AAT), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1) and oxidised low-density lipoprotein (oxLDL) in matched cerebrospinal fluid (CSF) and plasma of 141 patients wit

Protein A and protein G ELISA for the detection of IgG autoantibodies against tissue transglutaminase in childhood celiac disease

Objectives: To investigate if the detection of celiac disease (CD) in children was improved by using alternative conjugates for assessment of tissue transglutaminase (tTG) autoantibodies. Methods: Serum samples from 108 biopsy confirmed CD children and 42 control subjects were investigated for the presence of autoantibodies with tTG coated microplates using protein A (PA), protein G (PG), anti-IgG

The humoral immune response to Helicobacter pylori infection in children with gastrointestinal symptoms

The prevalence of Helicobacter pylori is high in Eastern Europe. The purpose of this study was to estimate the prevalence of H. pylori in symptomatic Lithuanian children and to identify the infection by clinicopathological and serological analyses. One hundred sixteen symptomatic children (age 8-16) with gastritis and duodenal ulcer were included. Biopsies were histologically assessed according to

PMMA particles and pressure - a study of the osteolytic properties of two agents proposed to cause prosthetic loosening

Amongst the wear debris particles implicated in the particle hypothesis for prosthetic loosening are polymethylmethacrylate (PMMA), and particularly PMMA with barium sulphate contrast agent. Another suggested cause for loosening is hydrostatic pressure. PMMA particles were combined with hydrostatic pressure in a study to investigate whether there could be a synergistic or additive effect between t

Does an active sun exposure habit lower the risk of venous thrombotic events? A D-lightful hypothesis

Background: Venous and arterial thrombotic complications exhibit a seasonal variation, with risk peaking in winter and dropping to a nadir in summer. We sought a possible correlation between sun exposure habits and venous thromboembolism (VTE) events. Methods: This was a cohort study comprising 40 000 women (1000 per year of age from 25 to 64 years) who were drawn from the southern Swedish populat

The evolution of sex ratios and sex-determining systems

Sex determination is a fundamental process governed by diverse mechanisms. Sex ratio selection is commonly implicated in the evolution of sex-determining systems, although formal models are rare. Here, we argue that, although sex ratio selection can induce shifts in sex determination, genomic conflicts between parents and offspring can explain why single-factor systems (e.g. XY/XX or ZW/ZZ) are co

A meta-analysis of prior corticosteroid use and fracture risk

The relationship between use of corticosteroids and fracture risk was estimated in a meta-analysis of data from seven cohort studies of similar to42,000 men and women. Current and past use of corticosteroids was an important predictor of fracture risk that was independent of prior fracture and BMD.

Posterior atlanto-axial dislocation in rheumatoid arthritis

Seven patients with rheumatoid arthritis and posterior atlanto-axial dislocation are presented. The patients were elderly women who had suffered with the disease a long time. In all cases earlier cervical radiographs were available, excluding any predisposing congenital anomaly. Fracture and arthritic destruction of the dens, of parts of the body of the axis, or of the anterior arch of the atlas p

The X4 phenotype of HIV type 1 evolves from R5 in two children of mothers, carrying X4, and is not linked to transmission

Previously, we found that emergence of the X4 viral phenotype in HIV-1-infected children was related to the presence of X4 in their mothers (C. H. Casper et al., J Infect Dis 2002; 186: 914-921). Here, we investigated the origin of the X4 phenotype in the child, analyzing two mother-child pairs (Ma-Ca, Mb-Cb) where the mothers carried X4 and their children developed X4 after an initial presence of

Testosterone in females: Mediator of adaptive traits, constraint on sexual dimorphism, or both?

When selection on males and females differs, the sexes may diverge in phenotype. Hormones serve as a proximate regulator of sex differences by mediating sex-biased trait expression. To integrate these perspectives, we consider how suites of traits mediated by the same hormone in both sexes might respond to selection. In male birds, plasma testosterone (T) varies seasonally and among species accord

Cerebral amyloid angiopathy, white matter lesions and Alzheimer encephalopathy - A histopathological assessment

To test the hypothesis that the cerebral amyloid angiopathy (CAA) of Alzheimer's disease (AD) is quantitatively associated with white matter lesions (WML), the brains of 63 demented patients exhibiting varying degrees of Alzheimer encephalopathy (AE) were examined, along with those of 10 nondemented control cases. The ratio of amyloid-positive to amyloid-negative vessels in the leptomeninges of th