154 research outputs found

    Characterization of an interleukin 4 (IL-4) responsive region in the immunoglobulin heavy chain germline epsilon promoter: regulation by NF-IL-4, a C/EBP family member and NF-kappa B/p50

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    A large body of data indicate that antibody class switching is directed by cytokines by inducing or repressing transcription from unrearranged, or germline, CH genes. Interleukin 4 (IL-4) induces transcription of the germline C epsilon genes in activated B cells and subsequently, cells in this population will undergo switch recombination to immunoglobulin E. Furthermore, the data suggest that transcription of germline C epsilon genes is required for class switching. In this paper we define DNA elements required for induction of transcription of the germline C epsilon genes by IL-4. To do this, segments of DNA from the 5\u27 flank of the initiation sites for germline epsilon RNA were ligated to a luciferase reporter gene and transfected into two mouse B cell lines, one of which can be induced to switch to IgE. By analysis of a series of 5\u27 deletion constructs and linker-scanning mutations, we demonstrate that a 46-bp segment (residing at -126/-79 relative to the first RNA initiation site) contains an IL-4 responsive region. By electrophoretic mobility shift assays, we find that this segment binds three transcription factors: the recently described NF-IL4, one or more members of the C/EBP family of transcription factors, and NF-kappa B/p50. Mutation of any of the binding sites for these three factors abolishes or reduces IL-4 inducibility of the epsilon promoter. A 27-bp segment within this IL-4 response region containing binding sites for NF-IL4 and a C/EBP factor is sufficient to transfer IL-4 inducibility to a minimal c-fos promoter

    Epidemiological aspects of surgical site infections in an income country. The case of regional hospital center, Borgou (Benin)

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    ABSTRACT Background: Surgical site infection is frustrating for the care team and depressing for the patient. Objective: To determine the epidemiological aspects of surgical site infections in regional hospital, Borgou. Methods: The study was crossed with prospective data collection. Recruitment was done for six months (from February 2013 to July 2013), each patient operated in both surgical services (general surgery and maternity) consents to be followed for one month or year. The surgical site infection was defined according to the CDC/NHSN 2009. Results: The frequency of surgical site infections was 7.3% (44/603). The mean age was 30.7 ± 15.8 years with minimum and maximum of 5 months and 70 years, respectively. They were significantly (p<0.05) more common in general surgery than that of maternity and visceral surgery and obstetrics were more concerned (14/44 each); the median time to SSI onset was 7.8 ± 3.8 days. The deep incisional infection was the most frequent (34/44). The most encountered organism was Escherichia coli (64.7%); multidrug resistance was 41.2%. The healing time averaged 30.5 ± 13.8 days with minimum and maximum of 20 and 92 days. Conclusion: Monitoring measures must be taken to reduce surgical site infection at the Regional Hospital Centre of Borgou.Background: Surgical site infection is frustrating for the care team and depressing for the patient. Objective: To determine the epidemiological aspects of surgical site infections in regional hospital, Borgou. Methods: The study was crossed with prospective data collection. Recruitment was done for six months (from February 2013 to July 2013), each patient operated in both surgical services (general surgery and maternity) consents to be followed for one month or year. The surgical site infection was defined according to the CDC/NHSN 2009. Results: The frequency of surgical site infections was 7.3% (44/603). The mean age was 30.7 ± 15.8 years with minimum and maximum of 5 months and 70 years, respectively. They were significantly (p<0.05) more common in general surgery than that of maternity and visceral surgery and obstetrics were more concerned (14/44 each); the median time to SSI onset was 7.8 ± 3.8 days. The deep incisional infection was the most frequent (34/44). The most encountered organism was Escherichia coli (64.7%); multidrug resistance was 41.2%. The healing time averaged 30.5 ± 13.8 days with minimum and maximum of 20 and 92 days. Conclusion: Monitoring measures must be taken to reduce surgical site infection at the Regional Hospital Centre of Borgou

    RISK FACTORS OF SURGICAL SITE INFECTION AT THE REGIONAL AND TEACHING HOSPITAL CENTER OF BORGOU (BENIN)

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    Introduction: The reduction of the SSI rate requires knowledge of its risk factors. Objective: To analyze the risk factors of SSI occurrence at CHD-B Methods: Prospective, descriptive and analytical study involving 603 patients undergoing general surgery (218) and obstetrics and gynecology (385) from 1st&nbsp;January to 31st&nbsp;July 2013. Results: 44 patients have developed SSI (7.3%). The SSI frequency was 12.8% in general surgery and 4.2% in gynecology-obstetrics (p significant). The mean age of patients developing SSI was 30.7 ± 15.8 years with a minimum and maximum 5 months and 70 years, respectively; and for general surgery patients, there were 23 men and 5 women (p not significant). The presence of preoperative infectious spot at admission (P = 0.003), the preoperative shaving of the site to be incised (p = 0.000), the ASA score (p = 0.000), the surgery contamination class (p = 0.000), and the NNIS score (p = 0.000) were all significantly related to SSI occurrence. Considering all these factors, the NNIS score ≥2 remained the predictive tool by multiplying by 3.4 the risk of SSI occurrence. Conclusion: NNIS score is the best SSI prediction tool at CHD-B. KEYWORDS: Surgical site infection; Risk factor; NNIS score

    RISK FACTORS OF SURGICAL SITE INFECTION AT THE REGIONAL AND TEACHING HOSPITAL CENTER OF BORGOU (BENIN)

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    Introduction: The reduction of the SSI rate requires knowledge of its risk factors. Objective: To analyze the risk factors of SSI occurrence at CHD-B Methods: Prospective, descriptive and analytical study involving 603 patients undergoing general surgery (218) and obstetrics and gynecology (385) from 1st&nbsp;January to 31st&nbsp;July 2013. Results: 44 patients have developed SSI (7.3%). The SSI frequency was 12.8% in general surgery and 4.2% in gynecology-obstetrics (p significant). The mean age of patients developing SSI was 30.7 ± 15.8 years with a minimum and maximum 5 months and 70 years, respectively; and for general surgery patients, there were 23 men and 5 women (p not significant). The presence of preoperative infectious spot at admission (P = 0.003), the preoperative shaving of the site to be incised (p = 0.000), the ASA score (p = 0.000), the surgery contamination class (p = 0.000), and the NNIS score (p = 0.000) were all significantly related to SSI occurrence. Considering all these factors, the NNIS score ≥2 remained the predictive tool by multiplying by 3.4 the risk of SSI occurrence. Conclusion: NNIS score is the best SSI prediction tool at CHD-B. KEYWORDS: Surgical site infection; Risk factor; NNIS score

    Studies on lipovitellin in the back water shrimp Caridina nilotica (Roux, 1833)

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    Based on the morphological appearance, ovary of Caridina nilotica was segregated as four maturation stages (I to IV). The biochemical parameters were significantly varied during maturation. Vitellin was quantified from non-denatured PAGE and noted that it positively increased during the ovarian developmental stages. This protein was considered as a lipoglyco nucleic acid binding protein based on specific staining

    Non-Photochemical Quenching in Cryptophyte Alga Rhodomonas salina Is Located in Chlorophyll a/c Antennae

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    Photosynthesis uses light as a source of energy but its excess can result in production of harmful oxygen radicals. To avoid any resulting damage, phototrophic organisms can employ a process known as non-photochemical quenching (NPQ), where excess light energy is safely dissipated as heat. The mechanism(s) of NPQ vary among different phototrophs. Here, we describe a new type of NPQ in the organism Rhodomonas salina, an alga belonging to the cryptophytes, part of the chromalveolate supergroup. Cryptophytes are exceptional among photosynthetic chromalveolates as they use both chlorophyll a/c proteins and phycobiliproteins for light harvesting. All our data demonstrates that NPQ in cryptophytes differs significantly from other chromalveolates – e.g. diatoms and it is also unique in comparison to NPQ in green algae and in higher plants: (1) there is no light induced xanthophyll cycle; (2) NPQ resembles the fast and flexible energetic quenching (qE) of higher plants, including its fast recovery; (3) a direct antennae protonation is involved in NPQ, similar to that found in higher plants. Further, fluorescence spectroscopy and biochemical characterization of isolated photosynthetic complexes suggest that NPQ in R. salina occurs in the chlorophyll a/c antennae but not in phycobiliproteins. All these results demonstrate that NPQ in cryptophytes represents a novel class of effective and flexible non-photochemical quenching

    Bmcc1s, a Novel Brain-Isoform of Bmcc1, Affects Cell Morphology by Regulating MAP6/STOP Functions

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    The BCH (BNIP2 and Cdc42GAP Homology) domain-containing protein Bmcc1/Prune2 is highly enriched in the brain and is involved in the regulation of cytoskeleton dynamics and cell survival. However, the molecular mechanisms accounting for these functions are poorly defined. Here, we have identified Bmcc1s, a novel isoform of Bmcc1 predominantly expressed in the mouse brain. In primary cultures of astrocytes and neurons, Bmcc1s localized on intermediate filaments and microtubules and interacted directly with MAP6/STOP, a microtubule-binding protein responsible for microtubule cold stability. Bmcc1s overexpression inhibited MAP6-induced microtubule cold stability by displacing MAP6 away from microtubules. It also resulted in the formation of membrane protrusions for which MAP6 was a necessary cofactor of Bmcc1s. This study identifies Bmcc1s as a new MAP6 interacting protein able to modulate MAP6-induced microtubule cold stability. Moreover, it illustrates a novel mechanism by which Bmcc1 regulates cell morphology

    C-terminal diversity within the p53 family accounts for differences in DNA binding and transcriptional activity

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    The p53 family is known as a family of transcription factors with functions in tumor suppression and development. Whereas the central DNA-binding domain is highly conserved among the three family members p53, p63 and p73, the C-terminal domains (CTDs) are diverse and subject to alternative splicing and post-translational modification. Here we demonstrate that the CTDs strongly influence DNA binding and transcriptional activity: while p53 and the p73 isoform p73γ have basic CTDs and form weak sequence-specific protein–DNA complexes, the major p73 isoforms have neutral CTDs and bind DNA strongly. A basic CTD has been previously shown to enable sliding along the DNA backbone and to facilitate the search for binding sites in the complex genome. Our experiments, however, reveal that a basic CTD also reduces protein–DNA complex stability, intranuclear mobility, promoter occupancy in vivo, target gene activation and induction of cell cycle arrest or apoptosis. A basic CTD therefore provides both positive and negative regulatory functions presumably to enable rapid switching of protein activity in response to stress. The different DNA-binding characteristics of the p53 family members could therefore reflect their predominant role in the cellular stress response (p53) or developmental processes (p73)

    Specific Recognition of p53 Tetramers by Peptides Derived from p53 Interacting Proteins

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    Oligomerization plays a major role in regulating the activity of many proteins, and in modulating their interactions. p53 is a homotetrameric transcription factor that has a pivotal role in tumor suppression. Its tetramerization domain is contained within its C-terminal domain, which is a site for numerous protein-protein interactions. Those can either depend on or regulate p53 oligomerization. Here we screened an array of peptides derived from proteins known to bind the tetrameric p53 C-terminal domain (p53CTD) and identified ten binding peptides. We quantitatively characterized their binding to p53CTD using fluorescence anisotropy. The peptides bound tetrameric p53CTD with micromolar affinities. Despite the high charge of the binding peptides, electrostatics contributed only mildly to the interactions. NMR studies indicated that the peptides bound p53CTD at defined sites. The most significant chemical shift deviations were observed for the peptides WS100B(81–92), which bound directly to the p53 tetramerization domain, and PKCα(281–295), which stabilized p53CTD in circular dichroism thermal denaturation studies. Using analytical ultracentrifugation, we found that several of the peptides bound preferentially to p53 tetramers. Our results indicate that the protein-protein interactions of p53 are dependent on the oligomerization state of p53. We conclude that peptides may be used to regulate the oligomerization of p53

    Conformational Altered p53 as an Early Marker of Oxidative Stress in Alzheimer's Disease

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    In order to study oxidative stress in peripheral cells of Alzheimer's disease (AD) patients, immortalized lymphocytes derived from two peculiar cohorts of patients, referring to early onset AD (EOSAD) and subjects harboured AD related mutation (ADmut), were used. Oxidative stress was evaluated measuring i) the typical oxidative markers, such as HNE Michel adducts, 3 Nitro-Tyrosine residues and protein carbonyl on protein extracts, ii) and the antioxidant capacity, following the enzymatic kinetic of superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GRD). We found that the signs of oxidative stress, measured as oxidative marker levels, were evident only in ADmut but not in EOSAD patients. However, oxidative imbalance in EOSAD as well as ADmut lymphocytes was underlined by a reduced SOD activity and GRD activity in both pathological groups in comparison with cells derived from healthy subjects. Furthermore, a redox modulated p53 protein was found conformational altered in both EOSAD and ADmut B lymphocytes in comparison with control cells. This conformational altered p53 isoform, named “unfolded p53”, was recognized by the use of two specific conformational anti-p53 antibodies. Immunoprecipitation experiments, performed with the monoclonal antibodies PAb1620 (that recognizes p53wt) and PAb240 (that is direct towards unfolded p53), and followed by the immunoblotting with anti-4-hydroxynonenal (HNE) and anti- 3-nitrotyrosine (3NT) antibodies, showed a preferential increase of nitrated tyrosine residues in unfolded p53 isoform comparing to p53 wt protein, in both ADmut and EOSAD. In addition, a correlation between unfolded p53 and SOD activity was further found. Thus this study suggests that ROS/RNS contributed to change of p53 tertiary structure and that unfolded p53 can be considered as an early marker of oxidative imbalance in these patients
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