Dermatological conditions during TNF-α-blocking therapy in patients with rheumatoid arthritis: a prospective study

Various dermatological conditions have been reported during tumor necrosis factor (TNF)-α-blocking therapy, but until now no prospective studies have been focused on this aspect. The present study was set up to investigate the number and nature of clinically important dermatological conditions during TNF-α-blocking therapy in patients with rheumatoid arthritis (RA). RA patients starting on TNF-α-blocking therapy were prospectively followed up. The numbers and natures of dermatological events giving rise to a dermatological consultation were recorded. The patients with a dermatological event were compared with a group of prospectively followed up RA control patients, naive to TNF-α-blocking therapy and matched for follow-up period. 289 RA patients started TNF-α-blocking therapy. 128 dermatological events were recorded in 72 patients (25%) during 911 patient-years of follow-up. TNF-α-blocking therapy was stopped in 19 (26%) of these 72 patients because of the dermatological event. More of the RA patients given TNF-α-blocking therapy (25%) than of the anti-TNF-α-naive patients (13%) visited a dermatologist during follow-up (P < 0.0005). Events were recorded more often during active treatment (0.16 events per patient-year) than during the period of withdrawal of TNF-α-blocking therapy (0.09 events per patient-year, P < 0.0005). The events recorded most frequently were skin infections (n = 33), eczema (n = 20), and drug-related eruptions (n = 15). Other events with a possible relation to TNF-α-blocking therapy included vasculitis, psoriasis, drug-induced systemic lupus erythematosus, dermatomyositis, and a lymphomatoid-papulosis-like eruption. This study is the first large prospective study focusing on dermatological conditions during TNF-α-blocking therapy. It shows that dermatological conditions are a significant and clinically important problem in RA patients receiving TNF-α-blocking therapy.     

Detection of microspheres in vivo using multispectral optoacoustic tomography

We introduce a new approach to detect individual microparticles that contain NIR fluorescent dye by multispectral optoacoustic tomography in the context of the hemoglobin-rich environment within murine liver. We encapsulated a near infrared (NIR) fluorescent dye within polystyrene microspheres, then injected them into the ileocolic vein, which drains to the liver. NIR absorption was determined using multispectral optoacoustic tomography. To quantitate the minimum diameter of microspheres, we used both colorimetric and spatial information to segment the regions in which the microspheres appear. Regional diameter was estimated by doubling the maximum regional distance. We found that the minimum microsphere size threshold for detection by multispectral optoacoustic tomography images is 78.9 µm.     

Biological equilibrium in ecosystems 3. Classification of ecosystems

The Theory of Biological Equilibrium (TBE) is applied to the classification of ecosystems. It is shown that one of the basic factors, the habitat-type, governs the distribution of species through the subfactors climate and substrate in accordance with the Theory of Tolerance. Groups of species can be distinguished which show a very similar distribution, and combinations of species in these groups form the kengroups of classification units, or associations. Because the habitat-type of associations is often fragmented, the classification procedures can be applied to explaint the natural extinction of species, as well as the probability of species extinction through man's actions upon biocenoses.     

Biological equilibrium in ecosystems 1. A theory of biological equilibrium

In this paper the process of establishing equilibrium in ecosystems is explored, and compared to the process of transformation. This process changes the state of organisms from absent to present, and the reverse, and if functioning randomly on very large numbers of individuals, results in biological equilibrium which can be expressed by the ratio (e?x): 1, withx=1 at Natural Biological Equilibrium (NBE). A model of ecosystems shows that four basic factors are operative in ecosystems: the constraint, or habitat-type; the regulator, or carrying capacity of the substrate; the input, or organisms; and the operator, death. The Theory of Biological Equilibrium (TBE) proposed, postulates that Natural Biological Equilibrium is reached when the individuals in an ecosystem are in dynamic balance with the carrying capacity of the substrate of the ecosystem. The TBE provides the theoretical basis for the Canonical Hypothesis, which postulates that the parameters in eco- systems are fixed, and can be computed from the number of species in the system. The TBE is in agreement with many well-known ecological phenomena, provides the basis for several hypotheses, and forces the rejection of some traditional hypotheses, viz., the hypothesis of competition as a factor in ecosystems.     

Trends in High-Risk Sexual Behaviors among General Population Groups in China: A Systematic Review

Background

The objective of this review was to investigate whether Chinese population groups that do not belong to classical high risk groups show an increasing trend of engaging in high-risk sexual behaviors.

Methods

We systematically searched the English and Chinese literature on sexual risk behaviors published between January 1980 and March 2012 in PubMed and the China National Knowledge Infrastructure (CNKI). We included observational studies that focused on population groups other than commercial sex workers (CSWs) and their clients, and men who have sex with men (MSM) and quantitatively reported one of the following indicators of recent high-risk sexual behavior: premarital sex, commercial sex, multiple sex partners, condom use or sexually transmitted infections (STIs). We used generalized linear mixed model to examine the time trend in engaging in high-risk sexual behaviors.

Results

We included 174 observational studies involving 932,931 participants: 55 studies reported on floating populations, 73 on college students and 46 on other groups (i.e. out-of-school youth, rural residents, and subjects from gynecological or obstetric clinics and premarital check-up centers). From the generalized linear mixed model, no significant trends in engaging in high-risk sexual behaviors were identified in the three population groups.

Discussion

Sexual risk behaviors among certain general population groups have not increased substantially. These groups are therefore unlikely to incite a STI/HIV epidemic among the general Chinese population. Because the studied population groups are not necessarily representative of the general population, the outcomes found may not reflect those of the general population.     

Isoform switching facilitates period control in the Neurospora crassa circadian clock

A striking and defining feature of circadian clocks is the small variation in period over a physiological range of temperatures. This is referred to as temperature compensation, although recent work has suggested that the variation observed is a specific, adaptive control of period. Moreover, given that many biological rate constants have a Q₁₀ of around 2, it is remarkable that such clocks remain rhythmic under significant temperature changes. We introduce a new mathematical model for the Neurospora crassa circadian network incorporating experimental work showing that temperature alters the balance of translation between a short and long form of the FREQUENCY (FRQ) protein. This is used to discuss period control and functionality for the Neurospora system. The model reproduces a broad range of key experimental data on temperature dependence and rhythmicity, both in wild‐type and mutant strains. We present a simple mechanism utilising the presence of the FRQ isoforms (isoform switching) by which period control could have evolved, and argue that this regulatory structure may also increase the temperature range where the clock is robustly rhythmic.     

11beta-hydroxysteroid dehydrogenase type 1: a new regulator of fetal lung maturation.

Glucocorticoids (GCs) induce surfactant synthesis in the late fetal lung. Deficient GC action causes respiratory distress syndrome. 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) converts inert cortisone (11-dehydrocorticosterone in rodents) into active cortisol (corticosterone), thus amplifying intracellular GC action. We investigated 11beta-HSD1 in the late fetal lung using the licorice-derived inhibitor, glycyrrhetinic acid (GE), in pregnant rats (day 13 of gestation until term). Control fetal mice and rats showed high 11beta-HSD activity in the late fetal lung; levels of plasma 11-dehydrocorticosterone were also high. Reduction/loss of pulmonary 11beta-HSD1 activity in GE-treated rats substantially impaired fetal lung maturation. Lungs from GE-exposed rats had lower surfactant protein-A (mRNA and protein) levels and reduced amniotic fluid lecithin/sphingomyelin ratios. There was a marked depletion of lung surfactant before and after birth, as detected by both light and electron microscopy. The data emphasize the importance of 11beta-HSD1 in amplifying key GC-dependent maturational processes in the late fetal lung.