Psoriasis vulgaris and genetic markers

Summary In a sample of n=160 nonrelated male and female patients suffering from psoriasis vulgaris, blood, serum protein, and enzyme group typings have been carried out and compared with healthy controls from the same area (Rheinland-Pfalz). Marked statistically significant differences between patients and controls were found in none of the genetic blood polymorphisms considered here. However, combining previously published data from various authors with our own, significant associations between this skin disease and genetic polymorphisms such as MN, Gc, Gm(2), red cell acid phosphatase, and red cell phosphoglucomutase (PGM₁) were seen. The possible reasons for these associations are discussed.     

Serum depletion of corticosteroid binding activities,an early marker of human septic shock

We report that human sera within 24 hours after the onset of septic shock are virtually depleted of the corticosteroid binding activities characteristic for transcortin. By contrast, transcortin activities are not changed significantly in cases of acute inflammation, though septic shock and inflammatory sera are comparable in other respects: they show similar responses of their haptoglobin, thyroxine binding prealbumin, endogenous cortisol and progesterone levels. The physiological meaning and clinical interest of these results are discussed.     

Rhabdoide fehlen den Schlie\zellen vonDrosera

Zusammenfassung WÄhrend die Epidermiszellen der KelchblÄtter vonDrosera Rhabdoide (Eiwei\spindeln) enthalten, fehlen diese den Schlie\zellen.     

Cell-to-cell channels with two independently regulated gates in series: Analysis of junctional conductance modulation by membrane potential,calcium, and pH

We study cell-to-cell channels, in cell pairs isolated from Chironomus salivary gland, by investigating the dependence of junctional conductance (gj) on membrane potentials (E1, E2), on Ca2+, and on H+, and we explore the interrelations among these dependencies; we use two separate voltage clamps to set the membrane potentials and to measure gj. We find gj to depend on membrane potentials whether or not a transjunctional potential is present. The pattern of gj dependence on membrane potentials suggests that each channel has two closure mechanisms (gates) in series. These gates pertain, respectively, to the two cell faces of the junction. By treating the steady-state gj as the resultant of two simultaneous but independent voltage-sensitive open/closed equilibria, one within each population of gates (i.e., one on either face of the junction), we develop a model to account for the steady-state gj vs. E relationship. Elevation of cytosolic Ca2+ or H+ at fixed E lowers gj, but at moderate concentrations of these ions this effect can be completely reversed by clamping to more negative E. Overall, the effect of a change in pCai or pHi takes the form of a parallel shift of the gj vs. E curve along the E axis, without change in slope. We conclude (1) that the patency of a cell-to-cell channel is determined by the states of patency of its two gates; (2) that the patency of the gates depends on membrane potentials (not on transjunctional potential), on pCai, and on pHi; (3) that pCai and pHi determine the position of the gj vs. E curve on the E axis; and (4) that neither Ca2+ nor H+ at moderate concentrations alters the voltage sensitivity of gj.     

Patterns in intraspecific interaction strengths and the stability of food webs

A common approach to analyse stability of biological communities is to calculate the interaction strength matrix. Problematic in this approach is defining intraspecific interaction strengths, represented by diagonal elements in the matrix, due to a lack of empirical data for these strengths. Theoretical studies have shown that an overall increase in these strengths enhances stability. However, the way in which the pattern in intraspecific interaction strengths, i.e. the variation in these strengths between species, influences stability has received little attention. We constructed interaction strength matrices for 11 real soil food webs in which four patterns for intraspecific interaction strengths were chosen, based on the ecological literature. These patterns included strengths that were (1) similar for all species, (2) trophic level dependent, (3) biomass dependent, or (4) death rate dependent. These four patterns were analysed for their influence on (1) ranking food webs by their stability and (2) the response in stability to variation of single interspecific interaction strengths. The first analysis showed that ranking the 11 food webs by their stability was not strongly influenced by the choice of diagonal pattern. In contrast, the second analysis showed that the response of food web stability to variation in single interspecific interaction strengths was sensitive to the choice of diagonal pattern. Notably, stability could increase using one pattern and decrease using another. This result asks for deliberate approaches to choose diagonal element values in order to make predictions on how particular species, interactions, or other food web parameters affect food web stability.     

Invasive migration of a mainland rodent to santa catalina island and its effect on the endemic species <Emphasis Type="Italic">Peromyscus slevini</Emphasis>

Santa Catalina Island has an endemic mouse, Peromyscus slevini, which is the only native rodent species on the island. However, specimens of P. fraterculus have been recorded on the island. P. fraterculus is the most common species of Peromyscus off Santa Catalina Island in the Baja California peninsula. The records show the absence of P. slevini in the 1990s and an increasing number of P. fraterculus during the 2000s. P. slevini has recently been collected in 2007. The current situation in Santa Catalina Island shows a strong expansion of P. fraterculus and the restriction of P. slevini to the canyons. This study confirms for the first time the recent invasion of a peninsular native species in one island on the Gulf of California. Peromyscus fraterculus is a better desert adapted species in contrast to P. slevini. Under those conditions, in the near future, P. slevini could be extinct.     

Redox Proteomic Analysis Reveals Oxidative Modifications of Proteins by Increased Levels of Intracellular Reactive Oxygen Species during Hypoxia Adaptation of Aspergillus fumigatus

Aspergillus fumigatus faces abrupt changes in oxygen concentrations at the site of infection. An increasing number of studies has demonstrated that elevated production of intracellular reactive oxygen species (ROS) under low oxygen conditions plays a regulatory role in modulating cellular responses for adaptation to hypoxia. To learn more about this process in A. fumigatus, intracellular ROS production during hypoxia has been determined. The results confirm increased amounts of intracellular ROS in A. fumigatus exposed to decreased oxygen levels. Moreover, nuclear accumulation of the major oxidative stress regulator AfYap1 is observed after low oxygen cultivation. For further analysis, iodoTMT labeling of redox‐sensitive cysteine residues is applied to identify proteins that are reversibly oxidized. This analysis reveals that proteins with important roles in maintaining redox balance and protein folding, such as the thioredoxin Asp f 29 and the disulfide‐isomerase PdiA, undergo substantial thiol modification under hypoxia. The data also show that the mitochondrial respiratory complex IV assembly protein Coa6 is significantly oxidized by hypoxic ROS. Deletion of the corresponding gene results in a complete absence of hypoxic growth, indicating the importance of complex IV during adaptation of A. fumigatus to oxygen‐limiting conditions.     

Beta-globin gene cluster haplotype distribution in five Brazilian Indian tribes

Haplotypes derived from five polymorphic restriction sites in the beta-globin gene cluster were investigated in 139 individuals from five different Brazilian Indian tribes by the polymerase chain reaction (PCR). Eight haplotypes were identified. Haplotypes 2 (+????) and 6 (?++?+) were the most frequent and were common to all tribes. Their prevalences ranged from 60% to 93% and from 3% to 18%, respectively. Average heterozy-gosity measured by the Gini-Simpson index is markedly reduced among these Brazilian Indians when compared with Europeans (56%), but much less (8%) in relation to Asiatics, suggesting the absence of an important bottleneck effect in the early colonization of South America. The coefficient of gene differentiation (GST′) was estimated as 0.082 among six Brazilian Indian tribes, but when only three Tupi-Mondé-speaking tribes were considered, this estimate was reduced to 0.030. © 1995 Wiley-Liss, Inc.