Cytokeratin No. 9, an epidermal type I keratin characteristic of a special program of keratinocyte differentiation displaying body site specificity

Plantar epidermis of the bovine heel pad as well as human plantar and palmar epidermis contain large amounts of an acidic (type I) keratin polypeptide (No. 9) of Mr 64,000 which so far has not been found in epidermis of other sites of the body. We present evidence for the keratinous nature of this protein, including its ability to form cytokeratin complexes and intermediate-sized filaments in vitro. We have isolated RNA from plantar epidermis of both species and show, using translation in vitro, that these polypeptides are genuine products of distinct mRNAs. Using immunofluorescence microscopy with specific antibodies against this protein, we demonstrate its location in most cells of suprabasal layers of plantar epidermis as well as in sparse keratinocytes which occur, individually or in small clusters, in upper layers of epidermis of other body locations. We conclude that cytokeratin No. 9 is characteristic of a special program of keratinocyte differentiation which during morphogenesis is expressed in most epidermal keratinocytes of soles and palms but only in a few keratinocytes at other body sites. This example of cell type-specific expression of a member of a multigene family in relation to a body site-related program of tissue differentiation raises important biological questions concerning the regulation of keratinocyte differentiation and morphogenesis as well as the function of such topological heterogeneity within a given type of tissue.     

Model studies of low-temperature optical transitions of photosynthetic reaction centers A-, LD-, CD-, ADMR- and LD-ADMR-spectra for Rhodopseudomonas viridis

The optical spectra of the reaction center (RC) of Rhodopseudomonas viridis including absorption (A), linear dichrosism (LD), circular dichroism (CD), absorption-detected magnetic resonance (ADMR) and its linear dichroism (LD-ADMR) are simulated by an exciton model. It involves the Q_y transitions of six prosthetic groups: four (bacteriochlorophyll-b molecules, two bacteriopheophytin-b molecules and the Soret bands B_y of the special-pair pigments, which couple most strongly with the corresponding Q_y transitions. For the ADMR-spectra additional excitations of the special-pair triplet are introduced. While interactions between the Q_y transitions and the B_y transitions are in principle determined from the structural arrangement of the pigments, the interactions to the other states are adjusted to fit the spectral features for the various transitions. The interaction of the newly introduced states are interpreted in terms of a simple model.     

Even the Smallest Non-Crop Habitat Islands Could Be Beneficial: Distribution of Carabid Beetles and Spiders in Agricultural Landscape

Carabid beetles and ground-dwelling spiders inhabiting agroecosystems are beneficial organisms with a potential to control pest species. Intensification of agricultural management and reduction of areas covered by non-crop vegetation during recent decades in some areas has led to many potentially serious environmental problems including a decline in the diversity and abundance of beneficial arthropods in agricultural landscapes. This study investigated carabid beetle and spider assemblages in non-crop habitat islands of various sizes (50 to 18,000 square metres) within one large field, as well as the arable land within the field, using pitfall traps in two consecutive sampling periods (spring to early summer and peak summer). The non-crop habitat islands situated inside arable land hosted many unique ground-dwelling arthropod species that were not present within the surrounding arable land. Even the smallest non-crop habitat islands with areas of tens of square metres were inhabited by assemblages substantially different from these inhabiting arable land and thus enhanced the biodiversity of agricultural landscapes. The non-crop habitat area substantially affected the activity density, recorded species richness and recorded species composition of carabid and ground-dwelling spider assemblages; however, the effects were weakened when species specialised to non-crop habitats species were analysed separately. Interestingly, recorded species richness of spiders increased with non-crop habitat area, whereas recorded species richness of carabid beetles exhibited an opposite trend. There was substantial temporal variation in the spatial distribution of ground-dwelling arthropods, and contrasting patterns were observed for particular taxa (carabid beetles and spiders). In general, local environmental conditions (i.e., non-crop habitat island tree cover, shrub cover, grass cover and litter depth) were better determinants of arthropod assemblages than non-crop habitat island size, indicating that the creation of quite small but diversified (e.g., differing in vegetation cover) non-crop habitat islands could be the most efficient tool for the maintenance and enhancement of diversity of ground-dwelling carabids and spiders in agricultural landscapes.     

Comparison of methods to detect biosurfactant production by diverse microorganisms

Three methods to detect biosurfactant production, drop collapse, oil spreading, and blood agar lysis, were compared for their ease of use and reliability in relation to the ability of the cultures to reduce surface tension. The three methods were used to test for biosurfactant production in 205 environmental strains with different phylogenetic affiliations. Surface tension of select strains that gave conflicting results with the above three methods was also measured. Sixteen percent of the strains that lysed blood agar tested negative for biosurfactant production with the other two methods and had little reduction in surface tension (values above 60 mN/m). Thirty eight percent of the strains that did not lyse blood agar tested positive for biosurfactant production with the other two methods and had surface tension values as low as 35 mN/m. There was a very strong, negative, linear correlation between the diameter of clear zone obtained with the oil spreading technique and surface tension (rs = -0.959) and a weaker negative correlation between drop collapse method and surface tension (rs = -0.82), suggesting that the oil spreading technique better predicted biosurfactant production than the drop collapse method. The use of the drop collapse method as a primary method to detect biosurfactant producers, followed by the determination of the biosurfactant concentration using the oil spreading technique, constitutes a quick and easy protocol to screen and quantify biosurfactant production. The large number of false negatives and positives obtained with the blood agar lysis method and its poor correlation to surface tension (rs = -0.15) demonstrated that it is not a reliable method to detect biosurfactant production.     

The genus Teliocrinus (Crinoidea,Echinodermata): a key taxon among pentacrinid stalked crinoids

The main characters of the stalked crinoids of the family Pentacrinitidae attributed to the genus Teliocrinus are re‐evaluated from a quantitative study of phenotype variation, new observations on arm and stalk articulations, and observation of ontogenetic trends. All of the specimens collected in the northern Indian Ocean belong to the same species, i.e. Teliocrinus springeri (Clark, 1909). However, two phenotypes living at different depths remain valid as subspecies: Teliocrinus springeri springeri (Clark, 1909) and Teliocrinus springeri liliaceus (Clark, 1909). Teliocrinus shares several ontogenetic trends with Endoxocrinus, especially in nonfunctional brachial articulations and stalk symplexies. Its assignment to the Diplocrininae is confirmed. A discussion of its affinities with pentacrinid fossil genera in which the crown is well preserved suggests that Diplocrininae could have first appeared during the Lower Cretaceous. A shortening of brachitaxes and a paedomorphic trend of stalk symplexies are the main other evolutionary traits. Nonfunctional articulations are frequently found at the paedomorphic pole of the heterochronic gradient, without clear derived characters. Classification of pentacrinids mainly based on such symplesiomorphy or paedomorphic characters must be definitively abandoned. However, in post‐Palaeozoic stalked crinoids the scarcity of well‐preserved fossils, the high frequency of paedomorphy, and convergent adaptive characters makes phylogenetic reconstruction only based on morphological characters very difficult and speculative. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 155 , 22–39.     

Drug-Eluting versus Bare-Metal Stent for Treatment of Saphenous Vein Grafts: A Meta-Analysis

Background

Saphenous vein grafts develop an aggressive atherosclerotic process and the efficacy of drug eluting stents (DES) in treating saphenous vein graft (SVG) lesions has not been convincingly demonstrated. The aim of this study was to review and analyze the current literature for controlled studies comparing DES versus bare metal stents (BMS) for treatment of SVG stenoses.

Methodology/Principal Findings

We searched several scientific databases and conference proceedings up to March 15, 2010 for controlled studies comparing target vessel revascularization (TVR) between DES and BMS. Summary odds ratios (OR) for the primary endpoint TVR and secondary endpoints infarction, stent thrombosis and death were calculated using random-effect models. A total of 29 studies (3 randomized controlled trials RCT) involving 7549 (202 in RCT) patients were included. The need for target vessel revascularization in the DES group tended to be lower compared to BMS for the 3 RCT (OR 0.50 [0.24–1.00]; p = 0.051) and for observational studies (0.62 [0.49–0.79]; p<0.001). There was no significant difference in the risk for myocardial infarction in the RCT (OR 1.25 [0.22–6.99]; p = 0.250) but a lower risk for DES based on the observational studies 0.68 [0.49–0.95]; p = 0.023. The risk for stent thrombosis was found to be non-different in the RCT (OR 0.78 [0.03–21.73], p = 0.885) while it was in favor of DES in the observational studies (0.58 [0.38 – 0.84]; p<0.001). The mortality was not significantly different between DES and BMS in the RCT''s (OR 2.22 [0.17 – 29.50]; p = 0.546) while the observation studies showed a decreased mortality in the DES group (0.69 [0.55–0.85]; p<0.001).

Conclusion

DES may decrease TVR rate in treatment of SVG stenoses. No differences in reinfarction rate, stent thrombosis or mortality was found between the DES and BMS groups in the RCT''s while the observational data showed lower risk for myocardial infarction, stent thrombosis and death in the DES group. This may be a result of patient selection bias in the observational studies or represent a true finding that was not the detected in the RCT analysis due to limited statistical power.     

Opportunistic testing of medically underserved women for cervical cancer in South Africa

OBJECTIVE: To determine the yield of opportunistic Pap smears taken in an unscreened and medically underserved population in the Transkei Region of South Africa. STUDY DESIGN: Cross-sectional study of 22,160 cervical cytology specimens from an unscreened population attending gynecologic outpatient clinics between January 1990 and December 1996. RESULTS: The overall prevalence of atypical squamous cells of uncertain significance (ASCUS), low grade squamous intraepithelial lesions (LSIL) and high grade squamous intraepithelial lesions (HSIL) was, respectively, 34.7%, 8.3% and 2.4%. The ASCUS: SIL ratio was 3:1. The prevalence of invasive squamous cell carcinoma was 1.6%. The yield of opportunistic Pap smears was 10.7% including only LSIL and HSIL. CONCLUSION: The pathologic process of precursor lesions of cervical cancer appears to start at an early age since > 20% of cases are diagnosed before the age of 30 years. In the absence of a national screening program, opportunistic testing of medically underserved women needs to be maintained and encouraged.