Early human disturbance of the natural environment recorded in annually laminated sediments of Lake Gosciaz,central Poland

Palynological records from the annually laminated sediments of Lake Gosciaz are presented for the period ca. 7600–3900 conventional B.P. Indications in percentage and influx diagrams of Mesolithic and Early Neolithic human impact on the natural environment around the lake are discussed and compared with the archaeological evidence. The first indications of human disturbance start at ca. 6700 B.P. and in the following period four disturbance phases with interruptions are distinguished. A relationship between the Elm Decline and an increasing thickness of annual sediment layers as a consequence of increased soil erosion is suggested. Some hitherto unrecognized or incompletely known microfossils are identified and figured, and their palaeoecological significance is discussed. The records of akinetes of Aphanizomenon probably indicate increasing eutrophication of the lake. Charred fragments of grass epidermis are possibly indicative of openings in the forest.     

Isolation and partial characterization of an unusual human immunodeficiency retrovirus from two persons of west-central African origin.

An unusual human retrovirus was isolated from two patients with persistent generalized lymphadenopathy who originate from West-Central Africa and are currently residing in Belgium. Although the virus shared a number of the same biological and morphological properties as human immunodeficiency retrovirus type 1 (HIV-1) and HIV-2, significant antigenic differences could be demonstrated. Several of the viral proteins also differed in molecular weight from the corresponding HIV-1 and HIV-2 proteins. Partial chemical cleavage of the most highly conserved viral proteins resulted in patterns which differed from those of HIV-1 and HIV-2. Furthermore, nucleic acid hybridization experiments were capable of discriminating between the virus types. Sequence analysis of the viral U3 region revealed a unique enhancer organization not found in other immunodeficiency viruses. The data indicated that the new isolate is more closely related to HIV-1 than to HIV-2 but clearly differs in a number of important respects.     

Typha as a wetland food resource: evidence from the Tianluoshan site,Lower Yangtze Region,China

Vegetation History and Archaeobotany - Wetlands have been attractive environments for early communities worldwide. In China, wetlands offered natural ecological settings for the start of rice...     

Cellular localization of oriC during the cell cycle of Escherichia coli as analyzed by fluorescent in situ hybridization

The origin of replication of Escherichia coli, oriC, has been labeled by fluorescent in situ hybridization (FISH). The E. coli K12 strain was grown under steady state conditions with a doubling time of 79 min at 28 degrees C. Under these growth conditions DNA replication starts in the previous cell cycle at -33 min. At birth cells possess two origins which are visible as two separated foci in fully labeled cells. The number of foci increased with cell length. The distance of foci from the nearest cell pole has been measured in various length classes. The data suggest: i) that the two most outwardly located foci keep a constant distance to the cell pole and they therefore move apart gradually in line with cell elongation; and ii) that at the initiation of DNA replication the labeled origins occur near the center of prospective daughter cells.     

Properties of triiodothyronine binding sites in cerebral cortical cytosol

Some properties of brain cytosol components that specifically bind L-triiodothyronine (T3) were examined in order to resolve their relevance and relationship to nuclear receptors. A marked variation in T3 binding activity was apparent among different brain areas. Binding exhibited temperature dependence and was maximal at 0 degrees C. The binding component was shown to be a protein that migrated as a single included peak on Sephadex G-100 columns at a position corresponding to a Stokes radium of 30A degrees and a M.W. of 54,000. On a linear glycerol gradient the T3-macromolecular complex was estimated to have a sedimentation constant of .4.2S. By combining sedimentation and gel filtration data the calculated M.W. was 53,000. With DEAE-cellulose chromatography the T3 complex eluted as a single peak at 115mM KH2PO4. The results indicate that the properties of the cytosol thyronine-binding protein are similar in many respects to those reported for nuclear receptors. In addition, the regional and developmental binding parameters parallel those for nuclei. We conclude that cytosolic recognition sites may function in the modulation of nuclear receptors and in addition serve to distinguish target from non-target tissue.     

The redox state of transglutaminase 2 controls arterial remodeling

While inward remodeling of small arteries in response to low blood flow, hypertension, and chronic vasoconstriction depends on type 2 transglutaminase (TG2), the mechanisms of action have remained unresolved. We studied the regulation of TG2 activity, its (sub) cellular localization, substrates, and its specific mode of action during small artery inward remodeling. We found that inward remodeling of isolated mouse mesenteric arteries by exogenous TG2 required the presence of a reducing agent. The effect of TG2 depended on its cross-linking activity, as indicated by the lack of effect of mutant TG2. The cell-permeable reducing agent DTT, but not the cell-impermeable reducing agent TCEP, induced translocation of endogenous TG2 and high membrane-bound transglutaminase activity. This coincided with inward remodeling, characterized by a stiffening of the artery. The remodeling could be inhibited by a TG2 inhibitor and by the nitric oxide donor, SNAP. Using a pull-down assay and mass spectrometry, 21 proteins were identified as TG2 cross-linking substrates, including fibronectin, collagen and nidogen. Inward remodeling induced by low blood flow was associated with the upregulation of several anti-oxidant proteins, notably glutathione-S-transferase, and selenoprotein P. In conclusion, these results show that a reduced state induces smooth muscle membrane-bound TG2 activity. Inward remodeling results from the cross-linking of vicinal matrix proteins, causing a stiffening of the arterial wall.     

In vivo vitiligo induction and therapy model: double-blind, randomized clinical trial

In this study, we developed an in vivo vitiligo induction model to explore the underlying mechanisms leading to Koebner's phenomenon and to evaluate the efficacy of therapeutic strategies. The model consisted of 12 pigmented test regions on the back of generalized vitiligo patients that were exposed to three Koebner induction methods: cryotherapy, 755 nm laser therapy, and epidermal abrasion. In addition, four cream treatments (pimecrolimus, tacrolimus, steroid and placebo) were randomly applied. Koebnerization was efficiently induced by all three induction methods. In general, cryotherapy was the best method of Koebner induction, followed by 755 nm laser therapy and epidermal abrasion. Reproducible results were obtained, which showed enhanced depigmented surface areas and higher amounts of T lymphocytes in placebo-treated test zones compared to active treated areas. Tacrolimus and local steroids were better inhibitors of Koebner's process (P < 0.05) compared to pimecrolimus. Our in vivo vitiligo induction model is very informative to investigate vitiligo induction and to determine the efficacy of topical treatments in vitiligo. This proof of concept confirms the efficient comparison of head-to-head therapeutic strategies intra-individually in a standardized, specific and better timed way.     

Revised classification/nomenclature of vitiligo and related issues: the Vitiligo Global Issues Consensus Conference

During the 2011 International Pigment Cell Conference (IPCC), the Vitiligo European Taskforce (VETF) convened a consensus conference on issues of global importance for vitiligo clinical research. As suggested by an international panel of experts, the conference focused on four topics: classification and nomenclature; definition of stable disease; definition of Koebner's phenomenon (KP); and 'autoimmune vitiligo'. These topics were discussed in seven working groups representing different geographical regions. A consensus emerged that segmental vitiligo be classified separately from all other forms of vitiligo and that the term 'vitiligo' be used as an umbrella term for all non-segmental forms of vitiligo, including 'mixed vitiligo' in which segmental and non-segmental vitiligo are combined and which is considered a subgroup of vitiligo. Further, the conference recommends that disease stability be best assessed based on the stability of individual lesions rather than the overall stability of the disease as the latter is difficult to define precisely and reliably. The conference also endorsed the classification of KP for vitiligo as proposed by the VETF (history based, clinical observation based, or experimentally induced). Lastly, the conference agreed that 'autoimmune vitiligo' should not be used as a separate classification as published evidence indicates that the pathophysiology of all forms of vitiligo likely involves autoimmune or inflammatory mechanisms.     

Solid-phase synthesis of C-terminally modified peptides.

In this paper, a straightforward and generic protocol is presented to label the C-terminus of a peptide with any desired moiety that is functionalized with a primary amine. Amine-functional molecules included are polymers (useful for hybrid polymers), long alkyl chains (used in peptide amphiphiles and stabilization of peptides), propargyl amine and azido propyl-amine (desirable for 'click' chemistry), dansyl amine (fluorescent labeling of peptides) and crown ethers (peptide switches/hybrids). In the first part of the procedure, the primary amine is attached to an aldehyde-functional resin via reductive amination. To the secondary amine that is produced, an amino acid sequence is coupled via a standard solid-phase peptide synthesis protocol. Since one procedure can be applied for any given amine-functional moiety, a robust method for C-terminal peptide labeling is obtained.