Experimental peri-implantitis around titanium implants with a chemically modified surface with a monolayer of multi-phosphonate molecules: a preclinical in vivo investigation.

OBJECTIVES: The purpose of this experimental in vivo investigation was to evaluate the influence of modifying the implant surface by adding a monolayer of multi-phosphonate molecules on the development of experimental peri-implantitis. MATERIAL AND METHODS: Eight beagle dogs received 5 tests and 5 control implants each following a split-mouth design 3 months after premolar and molar extraction. On the most mesial implant of each side, a 3-mm buccal dehiscence was artificially created. Experimental peri-implantitis was induced by silk ligatures over a 4-month period; after ligature removal, peri-implantitis was left to progress for another 4 months without plaque control. Clinical, histological, and radiographic outcomes were evaluated. RESULTS: Radiographically, both implant groups showed a similar bone loss (BL) at the end of the induction and progression phases. BL measured on the histological sections of the test and control groups was 3.14 ± 0.42 mm and 3.26 ± 0.28 mm, respectively; the difference was not statistically significant (p > 0.05). The remaining buccal bone to implant contact (bBIC) percentage of the test and control groups was 59.38 ± 18.62 and 47.44 ± 20.46%, respectively; the difference, however, was not statistically significant (p > 0.05). Bone loss observed at dehiscent sites compared to non-dehiscent ones showed no statistically significant difference (p > 0.05). CONCLUSIONS: Addition of a monophosphonate layer to a moderately rough implant surface did not affect development of experimental peri-implantitis. CLINICAL RELEVANCE: Influence of implant surface on peri-implantitis may condition implant selection by the clinician, especially on patients with disease risk factors. In that sense, monophosphate layer implants do not show higher peri-implantitis risk than control implants.

Alveolar crest contour changes after guided bone regeneration using different biomaterials: an experimental in vivo investigation.

OBJECTIVE: To evaluate the changes in alveolar contour after guided bone regeneration (GBR) with two different combinations of biomaterials in dehiscence defects around implants. MATERIAL AND METHODS: Chronic alveolar ridge defects were created bilaterally in the mandible of eight Beagle dogs. Once implants were placed, three treatment groups were randomly allocated to each peri-implant dehiscence defect: (i) test group received a bone substitute composed of hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP) covered by a cross-linked collagen membrane, (ii) positive control group with placement of deproteinized bovine bone mineral (DBBM) plus a porcine natural collagen membrane, and (iii) a negative control with no treatment. Two healing periods (8 and 16 weeks) were evaluated. Dental casts were optically scanned, the obtained files were uploaded into an image analysis software and superimposed to evaluate the linear changes. RESULTS: In both healing periods, the gains in linear contours were higher in the test group and at the intermediate level (3 mm below the gingival margin). While at 8 weeks, no significant differences were found between the groups; at 16 weeks, the test and positive control groups demonstrated significant gains in contour compared with negative control. CONCLUSIONS: GBR using different biomaterials significantly increased the buccal contours of the alveolar crest when used at dehiscence defects around dental implants. CLINICAL RELEVANCE: Particulate highly porous synthetic bone substitute and a cross-linked collagen membrane demonstrated similar outcomes in terms of contour augmentation when compared to bovine xenograft (DBBM) and a collagen membrane.

Effects of a 6-Week Period of Polarized or Threshold Training on Performance and Fatigue in Elite Swimmers.

PURPOSE: To quantify the impact of a polarized distribution of training intensity on performance and fatigue in elite swimmers. METHODS: Twenty-two elite junior swimmers (12 males, age = 17 [3] y, and 10 females, age = 17 [3] y) participated in a crossover intervention study over 28 wk involving 2- × 6-wk training periods separated by 6 wk. Swimmers were randomly assigned to a training group for the first period: polarized (81% in zone 1, blood lactate concentration, [La]b ≤ 2 mmol·L-1; 4% in zone 2, 2 mmol·L-1 < [La]b ≤ 4 mmol·L-1; and 15% in zone 3, [La]b > 4 mmol·L-1) or threshold (65%/25%/10%). Before and after each period, they performed a 100-m maximal swimming test to determine performance, maximal [La]b, and oxygen consumption and an incremental swimming test to determine speed corresponding to [La]b = 4 mmol·L-1 (V4 mmol·L-1). Self-reported indices of well-being were collected with a daily questionnaire. RESULTS: Polarized training elicited small to moderately greater improvement than threshold training on 100-m performance (within-group change ± 90% confidence interval: 0.97% ± 1.02% vs 0.09% ± 0.94%, respectively) with less fatigue and better quality of recovery. There was no substantial gender effect. No clear differences were observed in physiological adaptations between groups. CONCLUSIONS: In elite junior swimmers, a 6-wk period of polarized training induced small improvements in 100-m time-trial performance and, in combination with less perceived fatigue, forms a viable option for coaches preparing such cohorts of swimmers for competition.

[Hospital biomedical research through the satisfaction of a Health Research Institute professionals]. / La investigación biomédica hospitalaria a través de la satisfacción de los profesionales de un Instituto de Investigación Sanitaria.

OBJECTIVE: A Health Research Institute is a powerful strategic commitment to promote biomedical research in hospitals. To assess user satisfaction is an essential quality requirement. The aim of this study is to evaluate the professional satisfaction in a Health Research Institute, a hospital biomedical research centre par excellence. METHODS: Observational study was conducted using a satisfaction questionnaire on Health Research Institute researchers. The explored dimensions were derived from the services offered by the Institute to researchers, and are structured around 4 axes of a five-year Strategic Plan. A descriptive and analytical study was performed depending on adjustment variables. Internal consistency was also calculated. RESULTS: The questionnaire was completed by 108 researchers (15% response). The most valued strategic aspect was the structuring Areas and Research Groups and political communication and dissemination. The overall rating was 7.25 out of 10. Suggestions for improvement refer to the need for help in recruitment, and research infrastructures. High internal consistency was found in the questionnaire (Cronbach alpha of 0.9). CONCLUSIONS: So far research policies in health and biomedical environment have not been sufficiently evaluated by professionals in our field. Systematic evaluations of satisfaction and expectations of key stakeholders is an essential tool for analysis, participation in continuous improvement and advancing excellence in health research.

Management and outcomes in digestive cancer surgery: design and initial results of a multicenter cohort study.

BACKGROUND: most studies that analyze the influence of structure factors on clinical outcomes are retrospective, based on clinical-administrative databases, and mainly focusing on surgical volume. OBJECTIVE: to study variations in the process and outcomes of oncologic surgery for esophagus, stomach, pancreas, liver metastases and rectum cancers in Catalonia, as well as the factors associated with these variations. PATIENTS AND METHOD: a retrospective (2002) and prospective (2003-05) multicenter cohort study. Data forms were designed to collect patient, process, and care outcome characteristics before surgery, at hospital discharge, and at 3 and 6 months after discharge. Main outcome measures were hospital and follow-up mortality, complications, re-interventions, and relapse rates. RESULTS: 49 hospitals (80%) participated in the retrospective phase, 44 of which (90%) also participated in the prospective phase: 3,038 patients (98%) were included. No differences were observed in the profile of operated patients according to hospital level of complexity, but clinical-pathological staging and other functional status variables could not be assessed because of over 20% of missing values. There was significant variability in the volume of interventions as well as in certain aspects of the healthcare process depending on type of cancer and center complexity. High rates of esophageal cancer mortality (18.2% at discharge, 27.3% at 6 months) and of complications and re-interventions for all cancers assessed, especially rectal cancer (18.4% re-interventions at 6 months), were identified. CONCLUSIONS: the study of the variability identified will require adequate risk-adjustment and should take into account different structure factors. It is necessary that information included in medical records be improved.

Use of antioxidants to minimize rancidity in pressurized and cooked chicken slurries.

Sodium chloride (5%) and some antioxidants (400 ppm rosemary extract; 2000 ppm acerola extract; 50 ppm ethylenediamine tetraacetic acid (EDTA); 1,000, 2,000, and 5,000 pm of sodium hexametaphosphate or 5 and 10% egg white powder) were added to minced chicken. From these mixtures, slurries were made by mixing with water (1:3) at 15,000 rpm for 30 s at 20 °C. Samples were pressurized (300, 500 and 900 MPa for 30 min at 20 °C) or cooked (90 °C for 15 min). Hexanal was quantified by solid phase microextraction at 1, 3, 6 and 9 days of 4 °C storage in contact with air. Hexanal values increased with pressure and storage time. Cooked slurries had higher hexanal contents than samples pressurized at 300 MPa, but lower than those treated at 500 and 900 MPa. Rosemary extract was an antioxidant for pressure-treated samples, but had little effect on cooked ones. Acerola extract was not an effective antioxidant, but EDTA strongly inhibited oxidation. Hexamethaphosphate also showed antioxidant ability. Egg white powder inhibited hexanal generation, which can be a new way for revalorizing egg constituents.

Lipid oxidation of pressurized and cooked chicken: role of sodium chloride and mechanical processing on TBARS and hexanal values.

Lipid oxidation of pressurized (300 and 500 MPa for 30 min at 20 °C) or cooked (90 °C for 15 min) minced chicken breast and slurries was evaluated. Mechanical processing, before and after pressurization and cooking, and addition of sodium chloride were also tested as prooxidant factors. At 1, 3, 6 and 9 days of storage at 4 °C, thiobarbituric acid reactive substances (TBARS) and hexanal were quantified by means of the TBARS test and solid phase microextraction, respectively. In general, pressurized samples presented less oxidation compounds than cooked samples. Thiobarbituric acid reactive substances and hexanal values tended to rise with increasing storage time. Both parameters showed similar patterns throughout the experiment. Salt and mechanical processing had greater prooxidant effect on pressurized samples. Pre-treatment slurries presented more oxidation than post-treatment slurries.

Atmospheric quality and distribution of heavy metals in Argentina employing Tillandsia capillaris as a biomonitor.

The atmospheric quality and distribution of heavy metals were evaluated throughout a wide region of Argentina. In addition, the biomonitor performance of Tillandsia capillaris Ruiz & Pav. f. capillaris was studied in relation to the accumulation of heavy metals and to its physiologic response to air pollutants. A sampling area of 50,000 km2 was selected in the central region of the Argentine Republic. This area was subdivided into grids of 25 x 25 km. Pools of T. capillaris, where present, were collected at each intersection point. From each pool three sub-samples were analyzed independently. Furthermore, five replicates were collected at 20% of the points in order to analyze the variability within the site. The content of Co, Cu, Fe, Ni, Mn, Pb and Zn was determined by Atomic Absorption Spectrometry. Chemical-physiological parameters were also determined to detect symptoms of foliar damage. Chlorophylls, phaeophytins, hydroperoxy conjugated dienes, malondialdehyde and sulfur were quantified in T. capillaris. Some of these parameters were used to calculate a foliar damage index. Data sets were evaluated by one-way ANOVA, correlation analysis, principal component analysis and mapping. Geographical distribution patterns were obtained for the different metals reflecting the contribution of natural and anthropogenic emission sources. According to our results it can be inferred that Fe, Mn and Co probably originated in the soil. For Pb, the highest values were found in the mountainous area, which can be attributed to the presence of Pb in the granitic rocks. Ni showed mainly an anthropogenic origin, with higher values found in places next to industrial centers. For Zn the highest values were in areas of agricultural development. The same was observed for Cu, whose presence could be related to the employment of pesticides. The foliar damage index distribution map showed that the central and southeastern zones were the ones where the major damage in the bioindicator was found. The central zone coincides with the city of Córdoba whereas the southeastern area is strictly agricultural, so the high values found there could be related to the use of pesticides.

Evaluation of phosphodiesterase I-based protocols for the detection of multiply damaged sites in DNA: the detection of abasic, oxidative and alkylative tandem damage in DNA oligonucleotides.

It has been proposed that DNA multiply damaged sites (MDS), where more than one moiety in a local region ( approximately 1 helical turn, 10 bp) of the DNA is damaged, are lesions of enhanced biological significance. However, other than indirect measures, there are few analytical techniques that allow direct detection of MDS in DNA. In the present study we demonstrate the potential of protocols incorporating an exonucleolytic snake venom phosphodiesterase (SVPD) digestion stage to permit the direct detection of certain tandem damage, in which two lesions are immediately adjacent to each other on the same DNA strand. A series of prepared oligonucleotides containing either single or pairs of tetrahydrofuran moieties (F), thymine glycol lesions (T(g)) or methylphosphotriester adducts (Me-PTE) were digested with SVPD and the digests examined by either (32)P-end-labelling or electrospray mass spectrometry. The unambiguous observation of SVPD-resistant 'trimer' species in the digests of oligonucleotides containing adjacent F, T(g) and Me-PTE demonstrates that the SVPD digestion strategy is capable of allowing direct detection of certain tandem damage. Furthermore, in studies to determine the specificity of SVPD in dealing with pairs of lesions on the same strand, it was found mandatory to have the two lesions immediately adjacent to each other in order to generate the trimer species; pairs of lesions separated by as few as one or two normal nucleotides behave principally as single lesions towards SVPD.

Salmonella enteritidis and aerobic mesophiles in inoculated poultry sausages manufactured with high-pressure processing.

Salmonella enteritidis-inoculated poultry sausages were pressurized at 500 MPa by combining different times (10 and 30 min) and temperatures (50, 60 and 70 degrees C) or heat treated with the same temperature-time combinations and a standard cooking (75 degrees C for 30 min). Counts of Salm. enteritidis and mesophilic bacteria were determined. Most pressure treatments generated statistically higher reductions than the corresponding heat treatments alone. Lethalities of about 7.5 and 6.5 log cfu g(-1) for Salm. enteritidis and mesophiles, respectively, were found in pressurized sausages. There was no significant difference in counts between pressurization at 60 degrees C for 30 min or at 70 degrees C and the standard cooking. High-pressure processing is a suitable alternative method in poultry sausage manufacture.

High-pressure processing applied to cooked sausages: bacterial populations during chilled storage.

Vacuum-packaged cooked sausages were pressurized at 500 MPa for 5 or 15 min at mild temperature (65 degrees C) and later stored at 2 and 8 degrees C for 18 weeks. Counts of aerobic mesophiles and psychrotrophs, lactic acid bacteria, enterobacteria, Baird-Parker microbiota, and Listeria spp. were determined 1 day and 3, 6, 9, 12, 15, and 18 weeks after treatment and compared with those of cooked sausages treated at 80 to 85 degrees C for 40 min. Pressurization generated reductions of about 4 log CFU/g in psychrotrophs and lactic acid bacteria. Enterobacteria and Listeria proved the most pressure sensitive; insignificant or no growth was detected throughout the study. Heat treatment inactivated psychrotrophs and enterobacteria similarly to pressure treatment. Listeria monocytogenes and enterotoxigenic Staphylococcus aureus were not found in treated samples. In general, there was no significant difference in counts of any bacterial populations either among treatments or between storage temperatures. High-pressure processing at mild temperature is an effective preservation method that can replace heat pasteurization applied to some cooked meat and poultry products after packaging.

Pressure- vs. heat-induced bacterial stress in cooked poultry sausages: a preliminary study.

Vacuum-packaged poultry cooked sausages were pressure-treated at 500 MPa by combinations of time (5-45 min) and temperature (2-80 degrees C) and later stored at 6-8 degrees C for 12 we. Mesophile and psychrotrophe counts were determined 1 d, 3, 6, 9 and 12 we after treatment and compared with those of cooked sausages pasteurized at 80-85 degrees C for 40 min. Both pressure and heat treatments offer great possibilities for preservation. Sausages pressurized at 65 degrees C for 15 min showed mesophile numbers below 2 log cfu g(-1) throughout the chill storage. Pressurization, unlike heat treatment, causes a reversible bacterial stress. Thus, injured cells recovered during storage and, at 6 and 12 we, after a temperature abuse (room temperature for approx. 24 h), counts increased up to 6.5 - 7.5 log units. Psychrotrophes were more sensitive to both treatments; no growth was detected the day after (a lethality of more than 4 log units).

Mechanically recovered poultry meat sausages manufactured with high hydrostatic pressure.

The effect of high pressure processing at high temperature on texture and color of frankfurter-type sausages made with different contents of mechanically recovered poultry meat (MRPM) was evaluated and compared with that of a standard cooking process. Five types of sausages containing 100, 75, 50, 25, and 0% MRPM and 0, 25, 50, 75, and 100% of minced pork meat (MPM), respectively, were manufactured. They were pressurized at 500 MPa for 30 min at 50, 60, 70, and 75 C or cooked at 75 C for 30 min. Pressure-treated sausages were less springy and firm, but more cohesive. Moreover, color of pressurized sausages was lighter and more yellow than that of conventionally cooked sausages. Addition of MPM increased cohesiveness, hardness, and force at 80% compression. Minced pork meat also caused the appearance of sausages to be lighter, less red, and less yellow. Cooked sausages made with MRPM can have an attractive appearance and texture via high pressure processing.

Listeria innocua and aerobic mesophiles during chill storage of inoculated mechanically recovered poultry meat treated with high hydrostatic pressure.

Mechanically recovered poultry meat (MRPM) was inoculated with Listeria innocua 910 CECT at a level of approximately 10(8) CFU g(-1). Vacuum-packaged samples were treated by combinations of pressure (350, 400, 450 and 500 MPa), time (5, 10, 15 and 30 min) and temperature (2, 10 and 20°C) and later stored at 2°C for 2 months. Counts of L. innocua and aerobic mesophilic bacteria were determined 1, 4, 7, 15, 30 and 60 days after pressurisation. For mesophiles, in most treatments, pressurization at 2°C gave the significantly best results. High pressure caused a marked bactericidal effect on L. innocua: reductions higher than 7.5 log units were achieved in several cases. Some cells were just sublethally injured by pressure. Samples treated at 500 MPa for 30 min at 2°C had counts of only 2.3 log units after 60 days of chill storage. Noninoculated pressurised MRPM did not show Listeria growth throughout storage. These results suggest that high pressure processing can enhance the microbiological quality of MRPM.

Combined effect of nisin and high hydrostatic pressure on destruction of Listeria innocua and Escherichia coli in liquid whole egg.

High hydrostatic pressure inactivation of Escherichia coli and Listeria innocua inoculated in liquid whole egg was improved significantly (P < 0.05) with nisin addition at concentrations of 1.25 and 5 mg/1. A reduction of almost 5 log10 units in E. coli counts and more than 6 log10 units for L. innocua was obtained at 450 MPa and 5 mg/l of nisin. For this treatment, the two microorganisms were not detectable after 1 month of storage at 4 degrees C. The amount of nisin added did not affect E. coli inactivation at 300 MPa. For L. innocua, 5 mg/l of nisin was more effective than 1.25 mg/l. Nisin showed no effect when samples were stored at 20 degrees C after pressurization, except for samples with L. innocua containing 5 mg/l of nisin and treated with 450 MPa.

Inactivation of Listeria innocua inoculated in liquid whole egg by high hydrostatic pressure.

The resistance of Listeria innocua, as a model microorganism for Listeria monocytogenes, to high hydrostatic pressure in liquid whole egg was studied at several pressures (300, 350, 400, and 450 MPa),temperatures (- 15, 2, and 20 degrees C), and times (5, 10, and 15 min). Listeria innocus was added to liquid whole egg at approximately 10(6) CFU/ml. Listeria innocua was not totally inactivated in any of the treatments. In general, reduction was better at 2 degrees than at room temperature, but the greatest inactivation was obtained at 450 MPa at 20 degrees C for 15 min (over 5 log of reduction), The results indicate that microbial inactivation was increased with prolonged exposure to pressure. D values for Listeria innocua were obtained at 400 MPa for two temperatures (2 and 20 degrees C), and different times (0 to 20 min). The microbial inactivation followed apparent first-order kinetics, exhibiting a decimal reduction time of 7.35 min at 2 degrees C and 8.23 min at 20 degrees C.