Freeze-fracture study of Trichomonas vaginalis

The freeze-fracture technique was used to analyse the organization of the plasma membrane, as well as membranes of cytoplasmic organelles, of the pathogenic protozoan Trichomonas vaginalis. Rosettes formed by 4 to 14 intramembranous particles were seen on the fracture faces of the membrane lining the anterior flagella as well as in fracture faces of the plasma membrane enclosing the anterior region of the protozoan and in cytoplasmic organelles. Special organization of the membrane particles were also seen in the region of association of the recurrent flagellum to the cell body.

Stability of isoenzyme and kinetoplast DNA (k-DNA) patterns in successively cloned Trypanosoma cruzi populations

Four Trypanosoma cruzi strains from zymodermes A, B, C and D were successively clonedon BHI-LIT-agar-blood BLAB). Twenty clones from the first generation (F1), 10 from The second (F2) and 4 from the third (F3) from the strains A138, B147 and C23 were isolated. The D150 strain provied 29 F1 and F2 clones. The strains and clones had their isoenzyme and K-DNA patterns determined. The clones from A138, Bl47 and C231 strains presented isoemzyme and K-DNA patterns identical between thewmselves and their respective parental strains. Therefore showing the homogenety and stability of isoenzyme and K-DNA patterns after successive cloning. The Dl50 strain from zymodeme D (ZD) showed heterogeneity. Twenty-eight out of 29 clones of the first generation were of zymodeme A and only one was of zymodeme C, confirming previous reports that ZD strains consisted of ZA and ZC parasite populations. The only D150 strain clone of zymodeme C showed a K-DNA pattern identical to its parental strain. The remining clones although similar among themselves were different from the parental strain. Thus the T. cruzi strains had either homonogeneus or heterogeneous populations. The clones produced by successive cloning provided genetically homonogeous populations. Their experimental use will make future results more reliable and reproducible.

Infection rate of Babesia spp. sporokinetes in engorged Boophilus microplus from an area of enzootic stability in the State of Minas Gerais, Brazil

The infection rates of Babesia sporokinetes in engorged Boophilus microplus were evaluated during a 2-year period in a dairy farm located in an area of enzootic stability. Every 14 days engorged females were collected from calves and from adult animals. Ticks were incubated at 27 ± 0.5ºC and 80-90% relative humidity and Babesia infection rates were determined by microscopic examination of Giemsa-stained hemolymph smears. After 52 collections, 2105 ticks were obtained, from which 982 were collected from calves and 1123 from cows. The total Babesia infection rate was 10%, however the incidence was higher (p < 0.05) in ticks collected from calves (17.5%) than in those collected from cows (3.6%). Females collected from cows showed the highest infection rates in January, March, and August, and absence of infection in April and May. Ticks feeding on calves were infected throughout the experimental period. The infection rates of engorged females collected from naturally infected calves that were artificially infested with Babesia-free-larvae of B. microplus gradually decreased until the calves were four months old. No differences were observed among infection rates of ticks collected from calves maintained under natural conditions.

Pulmonary tuberculosis: evaluation of interferon-gamma levels as an immunological healing marker based on the response to the Bacillus Calmette-Guerin

Tuberculosis (TB) is a disease caused by Mycobacterium tuberculosis whose interaction with the host may lead to a cell-mediated protective immune response. The presence of interferon-g (IFN-gamma) is related to this response. With the purpose of understanding the immunological mechanisms involved in this protection, the lymphoproliferative response, IFN-g and other cytokines like interleukin (IL-5, IL-10), and tumor necrosis factor alpha (TNF-a) were evaluated before and after the use of anti-TB drugs on 30 patients with active TB disease, 24 healthy household contacts of active TB patients, with positive purified protein derivative (PPD) skin tests (induration > 10 mm), and 34 asymptomatic individuals with negative PPD skin test results (induration < 5 mm). The positive lymphoproliferative response among peripheral blood mononuclear cells of patients showed high levels of IFN-g, TNF-a, and IL-10. No significant levels of IL-5 were detected. After treatment with rifampicina, isoniazida, and pirazinamida, only the levels of IFN-g increased significantly (p < 0.01). These results highlight the need for further evaluation of IFN-g production as a healing prognostic of patients treated.

Differences in the stability of the plasmids of Yersinia pestis cultures in vitro: impact on virulence

Plasmid and chromosomal genes encode determinants of virulence for Yersinia pestis, the causative agent of plague. However, in vitro, Y. pestis genome is very plastic and several changes have been described. To evaluate the alterations in the plasmid content of the cultures in vitro and the impact of the alterations to their pathogenicity, three Y. pestis isolates were submitted to serial subculture, analysis of the plasmid content, and testing for the presence of characteristic genes in each plasmid of colonies selected after subculture. Different results were obtained with each strain. The plasmid content of one of them was shown to be stable; no apparent alteration was produced through 32 subcultures. In the other two strains, several alterations were observed. LD50 in mice of the parental strains and the derived cultures with different plasmid content were compared. No changes in the virulence plasmid content could be specifically correlated with changes in the LD50.

Assessing protein stability of the dimeric DNA-binding domain of E2 human papillomavirus 18 with molecular dynamics

The objective of this study is to understand the structural flexibility and curvature of the E2 protein of human papillomavirus type 18 using molecular dynamics (6 ns). E2 is required for viral DNA replication and its disruption could be an anti-viral strategy. E2 is a dimer, with each monomer folding into a stable open-faced β-sandwich. We calculated the mobility of the E2 dimer and found that it was asymmetric. These different mobilities of E2 monomers suggest that drugs or vaccines could be targeted to the interface between the two monomers.

Scientific production on the applicability of phenytoin in wound healing

Phenytoin is an anticonvulsant that has been used in wound healing. The objectives of this study were to describe how the scientific production presents the use ofphenytoinas a healing agent and to discuss its applicability in wounds. A literature review and hierarchy analysis of evidence-based practices was performed. Eighteen articles were analyzed that tested the intervention in wounds such as leprosy ulcers, leg ulcers, diabetic foot ulcers, pressure ulcers, trophic ulcers, war wounds, burns, preparation of recipient graft area, radiodermatitis and post-extraction of melanocytic nevi. Systemic use ofphenytoinin the treatment of fistulas and the hypothesis of topical use in the treatment of vitiligo were found. In conclusion, topical use ofphenytoinis scientifically evidenced. However robust research is needed that supports a protocol for the use ofphenytoinas another option of a healing agent in clinical practice.

Duration of smoking cessation for the prevention of surgical wound healing complications

The study aimed to find scientific evidence about the duration of preoperative smoking cessation required to reduce surgical wound healing complications. An integrative review was performed in the databases, Latin American and Caribbean Literature on Health Sciences (LILACS) and Medical Literature Analysis and Retrieval System Online (MEDLINE), from 08/17/2012 to 09/17/2012, using the keywords: tobacco use cessation and wound healing; tobacco use cessation and preoperative period; tobacco use cessation and perioperative period (LILACS) and tobacco use cessation and perioperative period; tobacco use cessation and wound healing (MEDLINE). Out of the 81 eligible studies, 12 were included. The duration of smoking cessation needed to reduce healing complications was at least four weeks (four studies with level of evidence I, three studies with level of evidence II, two studies with level of evidence IV, and one study with level of evidence VII).

Effectiveness of Enteral Nutritional Therapy in the Healing Process of Pressure Ulcers: A Systematic Review

OBJECTIVE To evaluate the effectiveness of enteral nutritional therapy (ENT) in the healing process of pressure ulcers (PU) in adults and the elderly. METHOD A systematic review whose studies were identified through the databases of Cochrane, MEDLINE/PubMed, SciELO, LILACS, EMBASE, CINAHL, Web of Science, and manual searches. It included randomized clinical trials (RCTs) without delimiting the period or language of publication, which addressed adults and elderly patients with pressure ulcers in a comparative treatment of enteral nutritional therapy and placebo or between enteral nutritional therapy with different compositions and dosages. RESULTS We included ten studies that considered different interventions. It resulted in more pressure ulcers healed in the groups that received the intervention. The included studies were heterogeneous with regard to patients, the type of intervention, the sample and the follow-up period, all of which made meta-analysis impossible. CONCLUSION Although the enteral nutritional therapy demonstrates a promotion of pressure ulcer healing, sufficient evidence to confirm the hypothesis was not found.

Effectiveness Of 2% And 4% Papain Gels In The Healing Of Venous Ulcers

OBJECTIVE To analyze the effectiveness of 2% and 4% papain gels in tissue repair of venous ulcers. METHOD Quasi-experimental study with consecutive sample of 16 patients with 30 venous ulcers treated at the outpatient clinic of a teaching hospital, from April to November in 2011, using a form for clinical assessment of the patient and its lesion. Variables were analyzed by Wilcoxon and McNemar test (p < 0.05). RESULTS Most participants were female; aged between 51 and 59 years; obese; with hypertension. Regarding ulcers, there was an average decrease of 7.9 cm2 (50% of its original size) in 90 days; 20% of the ulcers completely healed within 56.67 days. There was an increase in epithelialization, significant reduction in the slough and edema, improved depth, in the type and amount of exudate (p < 0.0001). CONCLUSION 2% and 4% papain gels were effective in healing venous ulcers.

Laser therapy in pressure ulcers: evaluation by the Pressure Ulcer Scale for Healing and Nursing Outcomes Classification

AbstractOBJECTIVETo describe the pressure ulcer healing process in critically ill patients treated with conventional dressing therapy plus low-intensity laser therapy evaluated by the Pressure Ulcer Scale for Healing (PUSH) and the result of Wound Healing: Secondary Intention, according to the Nursing Outcomes Classification (NOC).METHODCase report study according to nursing process conducted with an Intensive Care Unit patient. Data were collected with an instrument containing the PUSH and the result of the NOC. In the analysis we used descriptive statistics, considering the scores obtained on the instrument.RESULTSA reduction in the size of lesions of 7cm to 1.5cm of length and 6cm to 1.1cm width, in addition to the increase of epithelial tissue and granulation, decreased secretion and odor.CONCLUSIONThere was improvement in the healing process of the lesion treated with adjuvant therapy and the use of NOC allowed a more detailed and accurate assessment than the PUSH.

Spatial variability of aggregate stability in latosols under sugarcane

The spatial variability of soils under a same management system is differentiated, as expressed in the properties. The spatial variability of aggregate stability of a eutrophic Red Latosol (ERL) and a dystrophic Red Latosol (DRL) under sugarcane was characterized. Samples were collected in a regular 10 m grid, in the layers 0.0-0.2 and 0.2-0.4 m, with 100 points per area, and the following properties were determined: geometric mean diameter (GMD) of aggregates, mean weight diameter (MWD) of aggregates, percent of aggregates in the > 2.0 mm class and organic matter (OM) content. The eutrophic Red Latosol (ERL) had a higher aggregate stability thn the dystrophic Red Latosol (DRL), which may be attributed to the higher clay and OM content and the gibbsitic mineralogy of this soil class. The differentiated evolution of the studied Oxisols explains the wider range and lower variation coefficient and variability, for all properties studied in the eutrophic Red Latosol.

Aggregate stability as affected by short and long-term tillage systems and nutrient sources of a hapludox in southern Brazil

The ability of a soil to keep its structure under the erosive action of water is usually high in natural conditions and decreases under frequent and intensive cultivation. The effect of five tillage systems (NT = no-till; CP = chisel plowing and one secondary disking; CT = primary and two secondary distings; CTb = CT with crop residue burning; and CTr = CT with removal of crop residues from the field), combined with five nutrient sources (C = control, no nutrient application; MF = mineral fertilizers according to technical recommendations for each crop; PL = 5 Mg ha-1 y-1 fresh matter of poultry litter; CM = 60 m³ ha-1 y-1 slurry cattle manure; and SM = 40 m³ ha-1 y-1 slurry swine manure) on wet-aggregate stability was determined after nine years (four sampled soil layers) and on five sampling dates in the 10th year (two sampled soil layers) of the experiment. The size distribution of the air-dried aggregates was strongly affected by soil bulk density, and greater values of geometric mean diameter (GMD AD) found in some soil tillage or layer may be partly due to the higher compaction degree. After nine years, the GMD AD on the surface was greater in NT and CP compared to conventional tillage systems (CT, CTb and CTr), due to the higher organic matter content, as well as less soil mobilization. Aggregate stability in water, on the other hand, was affected by the low variation in previous gravimetric moisture of aggregates, which contributed to a high coefficient of variation of this attribute. The geometric mean diameter of water-stable aggregates (GMD WS) was highest in the 0.00-0.05 m layer in the NT system, in the layers 0.05-0.10 and 0.12-0.17 m in the CT, and values were intermediate in CP. The stability index (SI) in the surface layers was greater in treatments where crop residues were kept in the field (NT, CP and CT), which is associated with soil organic matter content. No differences were found in the layer 0.27-0.32 m. The effect of nutrient sources on GMD AD and GMD WS was small and did not affect SI.

Seeds enriched with phosphorus and molybdenum improve the contribution of biological nitrogen fixation to common bean as estimated by 15n isotope dilution

Seeds with a high concentration of P or Mo can improve the growth and N accumulation of the common bean (Phaseolus vulgaris L.), but the effect of enriched seeds on biological N2 fixation has not been established yet. This study aimed to evaluate the effect of seeds enriched with P and Mo on growth and biological N2 fixation of the common bean by the 15N isotope dilution technique. An experiment was carried out in pots in a 2 x 3 x 2 x 2 factorial design in randomized blocks with four replications, comprising two levels of soil applied P (0 and 80 mg kg-1), three N sources (without N, inoculated with rhizobia, and mineral N), two seed P concentrations (low and high), and two seed Mo concentrations (low and high). Non-nodulating bean and sorghum were used as non-fixing crops. The substrate was 5.0 kg of a Red Latosol (Oxisol) previously enriched with 15N and mixed with 5.0 kg of sand. Plants were harvested 41 days after emergence. Seeds with high P concentration increased the growth and N in shoots, particularly in inoculated plants at lower applied P levels. Inoculated plants raised from high P seeds showed improved nodulation at both soil P levels. Higher soil P levels increased the percentage of N derived from the atmosphere (%Ndfa) in bean leaves. Inoculation with the selected strains increased the %Ndfa. High seed P increased the %Ndfa in inoculated plants at lower soil P levels. High seed Mo increased the %Ndfa at lower soil P levels in plants that did not receive inoculation or mineral N. It is concluded that high seed P concentration increases the growth, N accumulation and the contribution of the biological N2 fixation in the common bean, particularly in inoculated plants grown at lower soil P availability.