The ability of four yeast DNA polymerase mutant strains to carry out the repair of DNA treated with MMS was studied. Mutation
in DNA polymerase Rev3, as well as the already known mutation in the catalytic subunit of DNA polymerase δ, were both found
to lead to the accumulation of single-strand breaks, which indicates defective repair. A double-mutant strain carrying mutations
in DNA polymerase δ and a deletion in the REV3 gene had a complete repair defect, both at permissive (23°C) and restrictive (38°C) temperatures, which was not observed
in other pairwise combinations of tested polymerase mutants. Other polymerases are not involved in the repair of exogenous
DNA methylation damage, since neither mutation in the DNA polymerase ɛ, nor deletion in the DNA polymerase IV (β70) gene, caused defective repair. The data obtained suggest that DNA polymerases δ and Rev3p are both necessary to perform
repair synthesis in the base-excision repair of methylation damage. The results are discussed in the light of current concepts
on the role of DNA polymerase Rev3 in mutagenesis.
Received: 18 November / 10 December 1996 相似文献
INTRODUCTION: Oxidative modification of proteins affects their biological properties. Previously we have shown that hypochlorite (HOCl), the product of activated neutrophils, enhances protein immunogenecity. Collagen type II, a primary component of cartilage, is commonly used in the induction of arthritis in animals (CIA). The aim of this study was to examine whether HOCl may affect immunogenic, tolerogenic, and arthritogenic properties of collagen. MATERIALS AND METHODS: DBA/J mice were injected with either native (CNAT) or chlorinated collagen (CHOCl) to induce arthritis. The effect of chlorination on collagen properties was measured by evaluation of incidence and severity of CIA. Moreover, the concentration of serum anti-collagen IgG antibodies and myeloperoxidase (MPO) activity in inflamed joints was determined. RESULTS: Mice immunized with CNAT in adjuvant developed arthritis (CIA) with an incidence of 69%. CNAT also exerted tolerogenic properties when injected intravenously either before or shortly after primary immunization, resulting in decreased incidence and severity of CIA, reduced MPO activity in inflamed joints, and lowered serum levels of anti-CNAT IgG anti-bodies. Chlorination of collagen significantly diminished its ability to induce CIA and to trigger generation of anti-CNAT IgG antibodies. Interestingly, chlorination did not affect tolerogenic properties of collagen administered prior to primary immunization with CNAT. CONCLUSIONS: These results suggest that chlorination of collagen may selectively affect functional epitopes of collagen. It is likely that in inflamed joints, neutrophil derived HOCl, in some circumstances, will destroy arthritogenic and immunogenic B cell epitopes, while regulatory T cell epitopes will be preserved. 相似文献
Numerous reports indicate that cyclic 3',5' guanosine monophosphate (cGMP) is involved in the regulation of immune processes. However, the mechanisms responsible for the synthesis of this nucleotide and its signaling pathways in immune cells are still not well recognized. The aim of our studies was to establish: 1) which form of guanylyl cyclase (GC) synthesizes cGMP in murine lymphoid organs and 2) whether the same organs express the isoforms PKG1alpha and/or PKG1beta of protein kinase G, known as possible target for synthesized cGMP. Cells isolated from thymus, lymph nodes, and spleen were treated with activators (SNP, ANP, CNP, STa) of soluble or particulate cyclases. Sodium nitroprusside (SNP) elevated intracellular cGMP 2-fold in thymic and lymph node cells and about 10-fold in spleen cells. Atrial natriuretic peptide (ANP) caused modest but statistically significant increases of cGMP in cells of all three organs. Additionally, spleen cells elevated their cGMP content about 2-fold in response to C-type natriuretic protein (CNP). In cellular homogenates of the all analyzed organs, the antibody anti-PKG1beta stained the 78 kDa band corresponding to the molecular mass of PKG1. Only homogenates of spleen cells were stained by the antibody recognizing PKG1alpha. Our results indicate that in the investigated organs cGMP may be synthesized mainly by soluble GC in response to nitric oxide. The modest increase of cGMP upon stimulation by ANP suggests that in all these organs either exists only a small subpopulation of cells that express particulate cyclase GC-A or GC-A is expressed at very low level. In spleen cells, however, cyclase GC-B appears to be the more active enzyme. Elevated cGMP concentration may in turn activate PKG1beta in thymus, lymph node, and spleen cells and also PKG1alpha in spleen cells. 相似文献
Summary The studies were carried out on male Wistar rats subjected to running within an electric rotating drum. The animals were divided into four experimental groups, differing one from another as to the duration of training. Each training session lasted 30 days. In the first group the daily run lasted 3 min, in the second group 5 min; in the third group, a 1 min run on the first day, and one min longer on each successive day; in the fourth group a 2 min run on the first day and for two min longer on each successive day.The determinations made prior to and after training included the peripheral blood erythrocyte (Er) and reticulocyte (Ret.) count, the hemoglobin concentration (Hb) and packed cell volume (PCV) and, determined by spectrophotometric methods, the activity of pyruvate kinase (PK), glucose-6-phosphate dehydrogenase (G6PD) and glutathione reductase (GR). Training induced an improvement of all enzymatic activities. The heavier the physical exertion, the more intensive was the enzymatic activity of red blood cells, due to the intensification of bone marrow erythropoetic activity under physical exertion and the appearance of young red cells in peripheral blood. All the experimental groups revealed a drop in erythrocyte count (Er), hemoglobin concentration (Hb), and hematocrit values (PCV), as well as an increase in the reticulocytes count (Ret) and in the activity of all the enzymes investigated. In the fourth group anemia was detected: prolonged endurance training decreased the RBC by 24.2%, Hb by 31.1%, PCV by 26.2% and increased the reticulocyte count by 881.6%. Pronounced loading with physical effort leads to shifts in the glucose utilization ratio along particular erythrocyte metabolic pathways. This change in enzymatic activities may prove to be one of the causes of faster elimination of old RBCs. 相似文献
An IUD (TCu220C) was inserted in 82 women during low-transverse cesarean section. No untoward effect on puerperal morbidity or lactation was observed and no serious complications occurred in this series. At 12 months the rates were zero for pregnancy and 7.7 for expulsion; the latter figure is comparable to that reported after immediate postplacental insertion of the same IUD model. Intracesarean IUD insertion is a procedure that deserves further promotion.
Resumen A 82 mujeres se les insertó un DIU (TCu220C) durante una cesárea transversa en el segmento bajo. No se observaron efectos adversos en la morbilidad puerperal y la lactancia y no ocurrieron complicaciones serias en esta serie. A los 12 meses la tasa de embarazos fue de cero y de 7,7 la de expulsiones; esta última cifra es comparable a la registrada después de la inserción postparto inmediato del mismo modelo du DIU. Por lo tanto, la inserción intracesárea de DIU se considera un procedimiento que merece mayor promoción.
Résumé Un dispositif intra-utérin (TCu220C) a été mis en place chez 82 femmes au cours d'une césarienne transverse basse. On a noté aucune répercussion défavorable sur la morbidité post-puerpérale ni sur l'allaitement et aucune complication sérieuse est apparue dans cette série. Au bout de douze mois, les fréquences étaient de zéro pour les grossesses et de 7,7 pour les expulsions. Les chiffres ultérieurs sont comparables à ce qui a été publié après insertion post-placentaire immédiate du même modèle de DIU. La mise en place d'un DIU au cours de la césarienne est une méthode qui mérite d'être plus largement répandue.
Summary Recurrent and severe infections and absence of thymic shadow in X-ray examination were observed in children with the transposition of the great arteries (TGA). Among 45 children (29 boys and 16 girls) with TGA whose age ranged from 3 days to 16 years and who were hospitalized during 1 year, infectious diarrhea was observed in 77.7% cases, urinary tract infections in 44.5%, respiratory tract infections in 42.2%, sepsis in 17.5%, and meningitis in 8.8%. Nine of the children died, sepsis was a cause of death in seven children, and there were postsurgical complications in two children. Immunologic abnormalities in children with TGA included a decreased level of T-lymphocytes and T29° subpopulation, impaired mitogen-induced lymphoproliferation in vitro, and increased nitro blue tetrazolium (NBT) reduction activity of monocytes. Impaired parameters of cellular immunity correlated with worst clinical status. No disorders of humoral immunity were observed. These observations may be important for forming opinion about proper therapy and the cause of death in children with TGA.All results have been included in T. Marek-Szydowska's doctoral dissertation and were communicated at the 65th Annual Meeting of Deutsche Gesellschaft für Rechtsmedizin, St. Gallen, Switzerland, Sept. 9–13, 1986 相似文献
Prevention Science - This study examined the impact of a state policy requiring that any school with a habitual truancy rate of 8% or higher to be trained in Tier 1 school-wide Positive Behavioral... 相似文献
BackgroundThe aim of this study was to assess the analgesic efficacy of sufentanil in dressings after surgical treatment of burn wounds.Patients and methodsTwenty adult patients, who underwent surgical treatment of third–degree burn wounds under general anesthesia, were included. Two of the patients underwent surgery twice. During surgery, patients received 50–100 μg fentanyl every 20–30 min and, after surgery, patients received 100 mg ketoprofen twice daily. Additionally, ten patients (group 1) received 50 μg sufentanil added to the burn wound dressings soaked in octenidine and phenoxyethanol while 10 patients (group 2) received 25 μg sufentanil added to the same dressings. The rescue analgesic, which was administered when pain intensified, was 5 mg subcutaneous morphine. Plasma sufentanil concentrations were assayed at 1, 2, 3, and 6 h after surgery completion and when pain was reported, along with pain intensity evaluation.ResultsSufentanil was not detected in the serum of any patients. Rescue morphine was given during the postoperative period (24 h) in one patient in group 1 (who underwent surgery twice) and three patients in group 2. The mean sufentanil concentration in dressings was higher in group 1 (0.13 ± 0.03) than group 2 (0.06 ± 0.03 μg/mL; p < 0.001). The group 1 patient who received rescue morphine had a sufentanil concentration of 0.10 μg/mL, which was the lowest concentration in group 1. Group 2 patients who received rescue morphine had sufentanil concentrations of at least two–fold lower (0.03–0.05 μg/mL). No adverse effects were observed.ConclusionsSufentanil in dressings after burn wound surgery provides effective and safe analgesia and the sufentanil concentration in dressings should be ≥0.10 μg/mL in a solution of octenidine and phenoxyethanol. 相似文献
People can express their identity in different ways, one of which is through language. Non-binary individuals often speak in a gender-neutral way and use specific language forms. Language use not only reveals their identity but also can shape how others perceive them. The present study’s purpose was to analyze how non-binary people are perceived through the language they use. The research was conducted in Polish, a language that is especially challenging for non-binary individuals because it has many gender markers. To avoid using gendered forms, they often use a specific form of passive voice. In an experiment, participants (N?=?130, 102 women, 28 men) read a gendered (feminine or masculine) text and a gender-neutral text with passive voice. Most gave a masculine name to the person in the neutral text, but addressed them in a gender-neutral way when asked to react to them in presented scenarios. The gender-neutral text was evaluated as being less comprehensible than the gendered texts, and the non-binary person was rated less competent and colder than a man or a woman and was less socially accepted. Furthermore, the negative evaluation of non-binary people seemed to be attributable to unfamiliarity with gender-neutral language and its lower comprehensibility. More research is needed to understand these perceptions better and to be able to prevent their potential negative consequences.
This article is devoted to convincing policy makers to use good practices in encouraging older people to pursue adequate and effective health policies. Long-term scientific research focused on the effects of health promotion programmes is rarely undertaken, although its scope is still expanding. At the same time, it is strongly desirable to form health policy based on scientific evidence. In this situation, an indication of good practices characterised by precisely defined features and their systematic evaluation could be an alternative to an insufficient number of empirical studies. The first step of the methodology was a literature review on health promotion for older people, aimed at defining good practices and criteria used for their selection. The authors searched the following databases: PubMED, Embase and Cochrane Library, as well as international databases dedicated to health promotion programmes for older people (e.g. Age-friendly World ( https://extranet.who.int/agefriendlyworld/age-friendly-practice-database-launched ); HealthProElderly ( www.healthproelderly.com/database/index.php?id=16 ); JA-CHRODIS ( www.chrodis.eu ); EuroHealthNet ( www.eurohealthnet.eu ) and ProFouND; ( www.profound.eu.com ). As relevant health policy information is usually available in national languages, the authors then approached national experts in 10 European countries, who filled in a dedicated survey on health promotion programmes for older people and indicated examples of good practices from their countries. Practical evidence, based on real implemented programmes, is valuable as inspiration for health promotion programmes, their planning and management. Selecting good practices from among implemented and evaluated actions makes it possible to establish their value. The significance of good practices in health promotion is to deliver real benefits and health effects for a target group, which, in the case of evident benefits, renders the practices credible and worthy of further dissemination. The EU already successfully shares good practices in migrant health and environmental protection. Creating databases on good practices helps policy makers promote the sustainability of already implemented activities and enhances their applicability by other organisations and in different settings. 相似文献