Partially Processed pre-rRNA Is Preserved in Association with Processing Components in Nucleolus-derived Foci during Mitosis

Previous studies showed that components implicated in pre-rRNA processing, including U3 small nucleolar (sno)RNA, fibrillarin, nucleolin, and proteins B23 and p52, accumulate in perichromosomal regions and in numerous mitotic cytoplasmic particles, termed nucleolus-derived foci (NDF) between early anaphase and late telophase. The latter structures were analyzed for the presence of pre-rRNA by fluorescence in situ hybridization using probes for segments of pre-rRNA with known half-lives. The NDF did not contain the short-lived 5′-external transcribed spacer (ETS) leader segment upstream from the primary processing site in 47S pre-rRNA. However, the NDF contained sequences from the 5′-ETS core, 18S, internal transcribed spacer 1 (ITS1), and 28S segments and also had detectable, but significantly reduced, levels of the 3′-ETS sequence. Northern analyses showed that in mitotic cells, the latter sequences were present predominantly in 45S-46S pre-rRNAs, indicating that high-molecular weight processing intermediates are preserved during mitosis. Two additional essential processing components were also found in the NDF: U8 snoRNA and hPop1 (a protein component of RNase MRP and RNase P). Thus, the NDF appear to be large complexes containing partially processed pre-rRNA associated with processing components in which processing has been significantly suppressed. The NDF may facilitate coordinated assembly of postmitotic nucleoli.

Nuclear foci of mammalian recombination proteins are located at single-stranded DNA regions formed after DNA damage

A sensitive and rapid in situ method was developed to visualize sites of single-stranded (ss) DNA in cultured cells and in experimental test animals. Anti-bromodeoxyuridine antibody recognizes the halogenated base analog incorporated into chromosomal DNA only when substituted DNA is in the single strand form. After treatment of cells with DNA-damaging agents or γ irradiation, ssDNA molecules form nuclear foci in a dose-dependent manner within 60 min. The mammalian recombination protein Rad51 and the replication protein A then accumulate at sites of ssDNA and form foci, suggesting that these are sites of recombinational DNA repair.

B lymphocyte involvement in ankylosing spondylitis: the heavy chain variable segment gene repertoire of B lymphocytes from germinal center-like foci in the synovial membrane indicates antigen selection

The synovial membrane (SM) of affected joints in ankylosing spondylitis (AS) is infiltrated by germinal center-like aggregates (foci) of lymphocytes similar to rheumatoid arthritis (RA). We characterized the rearranged heavy chain variable segment (VH) genes in the SM for gene usage and the mutational pattern to elucidate the B lymphocyte involvement in AS.

Conference on disease with natural foci and parasitological problems...[Moscow, Leningrad, Academy of Science USSR, 1959]

"Sponsored by the Academy of Sciences of the USSR (Zoological Institute, Leningrad) and the Academy of Medical Sciences (Institute of Epidemiology and Microbiology imeni)...N. F. Gamaley."

Naraazione storica contemporanea delle avventure e delle impresi di una flotta di crociati partita dalla foci della Schelda l'anno 1189. Letta 2. aprile 1840.

Text: De itinere navali de eventibus deque regus, a peregrinis Hierosolymam petentibus, 1589, fortiter gestis narratio," pp. [15-31].

Regulatory foci and organisational commitment

We use regulatory focus theory to derive specific predictions regarding the differential relationships between regulatory focus and commitment. We estimated a structural equation model using a sample of 520 private and public sector employees and found in line with our hypotheses that (a) promotion focus related more strongly to affective commitment than prevention focus, (b) prevention focus related more strongly to continuance commitment than promotion focus, (c) promotion and prevention focus had equally strong effects on normative commitment. Implications of these findings for the three-component model of commitment, especially the ‘dual nature’ of normative commitment, as well as implications for human resources management and leadership are discussed.

Marking high-technology market evolution through the foci of market stories:the case of local area networks

Previous research suggests that changing consumer and producer knowledge structures play a role in market evolution and that the sociocognitive processes of product markets are revealed in the sensemaking stories of market actors that are rebroadcasted in commercial publications. In this article, the authors lend further support to the story-based nature of market sensemaking and the use of the sociocognitive approach in explaining the evolution of high-technology markets. They examine the content (i.e., subject matter or topic) and volume (i.e., the number) of market stories and the extent to which content and volume of market stories evolve as a technology emerges. Data were obtained from a content analysis of 10,412 article abstracts, published in key trade journals, pertaining to Local Area Network (LAN) technologies and spanning the period 1981 to 2000. Hypotheses concerning the evolving nature (content and volume) of market stories in technology evolution are tested. The analysis identified four categories of market stories - technical, product availability, product adoption, and product discontinuation. The findings show that the emerging technology passes initially through a 'technical-intensive' phase whereby technology related stories dominate, through a 'supply-push' phase, in which stories presenting products embracing the technology tend to exceed technical stories while there is a rise in the number of product adoption reference stories, to a 'product-focus' phase, with stories predominantly focusing on product availability. Overall story volume declines when a technology matures as the need for sensemaking reduces. When stories about product discontinuation surface, these signal the decline of current technology. New technologies that fail to maintain the 'product-focus' stage also reflect limited market acceptance. The article also discusses the theoretical and managerial implications of the study's findings. © 2002 Elsevier Science Inc. All rights reserved.

Anti-leishmanial effects of purified compounds from aerial parts of Baccharis uncinella C. DC. (Asteraceae)

Species of Baccharis exhibit antibiotic, antiseptic, wound-healing, and anti-protozoal properties, and have been used in the traditional medicine of South America for the treatment of several diseases. In the present work, the fractionation of EtOH extract from aerial parts of Baccharis uncinella indicated that the isolated compounds caffeic acid and pectolinaringenin showed inhibitory activity against Leishmania (L.) amazonensis and Leishmania (V.) braziliensis promastigotes, respectively. Moreover, amastigote forms of both species were highly sensible to the fraction composed by oleanolic + ursolic acids and pectolinaringenin. Caffeic acid also inhibited amastigote forms of L. (L.) amazonensis, but this effect was weak in L. (V.) braziliensis amastigotes. The treatment of infected macrophages with these compounds did not alter the levels of nitrates, indicating a direct effect of the compounds on amastigote stages. The results presented herein suggest that the active components from B. uncinella can be important to the design of new drugs against American tegumentar leishmaniases.

Factors driving the abundance of ixodes ricinus ticks and the prevalence of zoonotic I. ricinus-borne pathogens in natural foci

Environmental factors may drive tick ecology and therefore tick-borne pathogen (TBP) epidemiology, which determines the risk to animals and humans of becoming infected by TBPs. For this reason, the aim of this study was to analyze the influence of environmental factors on the abundance of immature-stage Ixodes ricinus ticks and on the prevalence of two zoonotic I. ricinus-borne pathogens in natural foci of endemicity. I. ricinus abundance was measured at nine sites in the northern Iberian Peninsula by dragging the vegetation with a cotton flannelette, and ungulate abundance was measured by means of dung counts. In addition to ungulate abundance, data on variables related to spatial location, climate, and soil were gathered from the study sites. I. ricinus adults, nymphs, and larvae were collected from the vegetation, and a representative subsample of I. ricinus nymphs from each study site was analyzed by PCR for the detection of Borrelia burgdorferi sensu lato and Anaplasma phagocytophilum DNA. Mean prevalences of these pathogens were 4.0% ± 1.8% and 20.5% ± 3.7%, respectively. Statistical analyses confirmed the influence of spatial factors, climate, and ungulate abundance on I. ricinus larva abundance, while nymph abundance was related only to climate. Interestingly, cattle abundance rather than deer abundance was the main driver of B. burgdorferi sensu lato and A. phagocytophilum prevalence in I. ricinus nymphs in the study sites, where both domestic and wild ungulates coexist. The increasing abundance of cattle seems to increase the risk of other hosts becoming infected by A. phagocytophilum, while reducing the risk of being infected by B. burgdorferi sensu lato. Controlling ticks in cattle in areas where they coexist with wild ungulates would be more effective for TBP control than reducing ungulate abundance.

Testosterone Therapy Differently Regulates The Anti- And Pro-inflammatory Cytokines In The Plasma And Prostate Of Rats Submitted To Chronic Ethanol Consumption (uchb).

Ethanol consumption damages the prostate, and testosterone is known by anti-inflammatory role. The cytokines were investigated in the plasma and ventral prostate of UChB rats submitted or not to testosterone therapy by ELISA and Western blot, respectively. Additionally, inflammatory foci and mast cells were identified in the ventral prostate slides stained by hematoxylin and eosin and toluidine blue, respectively. Inflammatory foci were found in the ethanol-treated animals and absent after testosterone therapy. Plasma levels of IL-6 and IL-10 were not changed while TNFα and TFG-β1 were increased in the animals submitted testosterone therapy. Regarding to ventral prostate, IL-6 did not alter, while IL-10, TNFα, and TFG-β1 were increased after testosterone therapy. Ethanol increases NFR2 in addition to high number of intact and degranulated mast cell which were reduced after testosterone therapy. So, ethanol and testosterone differentially modulates the cytokines in the plasma and prostate.

Ten Years Of Proteomics In Multiple Sclerosis.

Multiple sclerosis, which is the most common cause of chronic neurological disability in young adults, is an inflammatory, demyelinating, and neurodegenerative disease of the CNS, which leads to the formation of multiple foci of demyelinated lesions in the white matter. The diagnosis is based currently on magnetic resonance image and evidence of dissemination in time and space. However, this could be facilitated if biomarkers were available to rule out other disorders with similar symptoms as well as to avoid cerebrospinal fluid analysis, which requires an invasive collection. Additionally, the molecular mechanisms of the disease are not completely elucidated, especially those related to the neurodegenerative aspects of the disease. The identification of biomarker candidates and molecular mechanisms of multiple sclerosis may be approached by proteomics. In the last 10 years, proteomic techniques have been applied in different biological samples (CNS tissue, cerebrospinal fluid, and blood) from multiple sclerosis patients and in its experimental model. In this review, we summarize these data, presenting their value to the current knowledge of the disease mechanisms, as well as their importance in identifying biomarkers or treatment targets.

Androgen Therapy Reverses Injuries Caused By Ethanol Consumption In The Prostate: Testosterone As A Possible Target To Ethanol-related Disorders.

Chronic ethanol consumption leads to reproductive damages, since it can act directly in the tissues or indirectly, causing a hormonal imbalance. Prostate is a hormone-dependent gland and, consequently, susceptible to ethanol. The potential of testosterone therapy in the ethanol-related disorders was investigated in the prostate microenvironment. UChB rats aged 90 days were divided into 2 experimental groups (n=20): C: drinking water only and EtOH: drinking 10% (v/v) ethanol at >2 g/kg body weight/day+water. At 150 days old, 10 rats from each group received subcutaneous injections of testosterone cypionate (5 mg/kg body weight) diluted in corn oil every other day for 4 weeks, constituting T and EtOH+T, while the remaining animals received corn oil as vehicle. Animals were euthanized at 180 days old, by decapitation. Blood was collected to obtain hormone concentrations and ventral prostate was dissected and processed for light microscope and molecular analyses. Ventral prostate weight, plasma testosterone and DHT and intraprostatic testosterone concentrations were increased after testosterone treatment. Plasma estradiol level was reduced in the EtOH+T. Inflammatory foci, metaplasia and epithelial atrophy were constantly found in the prostate of EtOH and were not observed after hormonal therapy. No differences were found in the expression of AR, ERβ and DACH-1. Additionally, testosterone treatment down-regulated ERα and increased the e-cadherin and α-actinin immunoreactivities. Testosterone was able to reverse damages caused by ethanol consumption in the prostate microenvironment and becomes a possible target to be investigated to ethanol-related disorders.

Fibrodysplasia ossificans progressiva: case report

Fibrodysplasia ossificans progressiva is a rare genetic disease characterized by widespread soft tissue ossification and congenital stigmata of the extremities. We report on a male child followed for ten years since the age of 3 years and 9 months, when the diagnosis was made. He was born with bilateral hypoplasic hallux valgus and ventricular septal defect, corrected by transsternal approach when 32 months old. Restriction of neck mobility followed and foci of ectopic ossification appeared. Four crises of disease exacerbation were treated with oral prednisone and/or other antiinflammatory drugs. Sodium etidronate 5 to 10 mg/kg/day was prescribed intermittently during about six years but was discontinued due to osteopenia. The disease course has been relentless, with severe movement restriction including the chest wall. A review showed few similar case reports in the Brazilian literature. We revisit the criteria for diagnosis and the essentials of management and treatment.