Prescription of antibiotic prophylaxis in implant placement among Portuguese dentists: A web survey

OBJECTIVES

This study aims to assess whether antibiotic prophylaxis for dental implant placement is commonly used by dentists in Portugal.

MATERIALS AND METHODS

This cross-sectional survey study was based on a web survey with 22 questions divided into 5 parts. The 1st part focused on demographic details, work experience, and academic expertise, whereas the 2nd and 3rd parts were about the pre- and postoperative antibiotic prescriptions. The 4th and 5th parts focused on dentists' motivation for using/avoiding antibiotic prophylaxis and the use of a protocol, respectively. Data interpretation included descriptive analysis and statistical inference via cross-tabling with chi-square adjusted standardised for residual effects.

RESULTS

Of the 204 valid surveys, at least one was received from every large Portuguese city which ensured the national coverage of the survey. Most respondents are not specialist dentists (72%). Sixty-four percent of the respondents always use antibiotic prophylaxis, while 29% adopt it only when grafting materials are employed. Most respondents use both pre- and postoperative regimens (55%). Amoxicillin 875 mg + clavulanic acid 125 mg is the most prescribed antibiotic (57%). Finally, the risk reduction of postoperative infection is the most frequent justification for the use of antibiotic prophylaxis (60%).

CONCLUSIONS

The results highlight that most of the respondents do not follow the consensual international guidelines for prophylactic antibiotherapy in dental implant placement surgeries. This finding should serve as a rationale to increase the dissemination of those guidelines.

Global importance of Indigenous Peoples, their lands, and knowledge systems for saving the world's primates from extinction

Primates, represented by 521 species, are distributed across 91 countries primarily in the Neotropic, Afrotropic, and Indo-Malayan realms. Primates inhabit a wide range of habitats and play critical roles in sustaining healthy ecosystems that benefit human and nonhuman communities. Approximately 68% of primate species are threatened with extinction because of global pressures to convert their habitats for agricultural production and the extraction of natural resources. Here, we review the scientific literature and conduct a spatial analysis to assess the significance of Indigenous Peoples' lands in safeguarding primate biodiversity. We found that Indigenous Peoples' lands account for 30% of the primate range, and 71% of primate species inhabit these lands. As their range on these lands increases, primate species are less likely to be classified as threatened or have declining populations. Safeguarding Indigenous Peoples' lands, languages, and cultures represents our greatest chance to prevent the extinction of the world's primates.

Primates in peril: the significance of Brazil, Madagascar, Indonesia and the Democratic Republic of the Congo for global primate conservation

Primates occur in 90 countries, but four-Brazil, Madagascar, Indonesia, and the Democratic Republic of the Congo (DRC)-harbor 65% of the world's primate species (439) and 60% of these primates are Threatened, Endangered, or Critically Endangered (IUCN Red List of Threatened Species 2017-3). Considering their importance for global primate conservation, we examine the anthropogenic pressures each country is facing that place their primate populations at risk. Habitat loss and fragmentation are main threats to primates in Brazil, Madagascar, and Indonesia. However, in DRC hunting for the commercial bushmeat trade is the primary threat. Encroachment on primate habitats driven by local and global market demands for food and non-food commodities hunting, illegal trade, the proliferation of invasive species, and human and domestic-animal borne infectious diseases cause habitat loss, population declines, and extirpation. Modeling agricultural expansion in the 21st century for the four countries under a worst-case-scenario, showed a primate range contraction of 78% for Brazil, 72% for Indonesia, 62% for Madagascar, and 32% for DRC. These pressures unfold in the context of expanding human populations with low levels of development. Weak governance across these four countries may limit effective primate conservation planning. We examine landscape and local approaches to effective primate conservation policies and assess the distribution of protected areas and primates in each country. Primates in Brazil and Madagascar have 38% of their range inside protected areas, 17% in Indonesia and 14% in DRC, suggesting that the great majority of primate populations remain vulnerable. We list the key challenges faced by the four countries to avert primate extinctions now and in the future. In the short term, effective law enforcement to stop illegal hunting and illegal forest destruction is absolutely key. Long-term success can only be achieved by focusing local and global public awareness, and actively engaging with international organizations, multinational businesses and consumer nations to reduce unsustainable demands on the environment. Finally, the four primate range countries need to ensure that integrated, sustainable land-use planning for economic development includes the maintenance of biodiversity and intact, functional natural ecosystems.

Impending extinction crisis of the world's primates: Why primates matter

Nonhuman primates, our closest biological relatives, play important roles in the livelihoods, cultures, and religions of many societies and offer unique insights into human evolution, biology, behavior, and the threat of emerging diseases. They are an essential component of tropical biodiversity, contributing to forest regeneration and ecosystem health. Current information shows the existence of 504 species in 79 genera distributed in the Neotropics, mainland Africa, Madagascar, and Asia. Alarmingly, ~60% of primate species are now threatened with extinction and ~75% have declining populations. This situation is the result of escalating anthropogenic pressures on primates and their habitats-mainly global and local market demands, leading to extensive habitat loss through the expansion of industrial agriculture, large-scale cattle ranching, logging, oil and gas drilling, mining, dam building, and the construction of new road networks in primate range regions. Other important drivers are increased bushmeat hunting and the illegal trade of primates as pets and primate body parts, along with emerging threats, such as climate change and anthroponotic diseases. Often, these pressures act in synergy, exacerbating primate population declines. Given that primate range regions overlap extensively with a large, and rapidly growing, human population characterized by high levels of poverty, global attention is needed immediately to reverse the looming risk of primate extinctions and to attend to local human needs in sustainable ways. Raising global scientific and public awareness of the plight of the world's primates and the costs of their loss to ecosystem health and human society is imperative.

Injectability of calcium phosphate pastes: Effects of particle size and state of aggregation of β-tricalcium phosphate powders

The present study discloses a systematic study about the influence of some relevant experimental variables on injectability of calcium phosphate cements. Non-reactive and reactive pastes were prepared, based on tricalcium phosphate doped with 5 mol% (Sr-TCP) that was synthesised by co-precipitation. The varied experimental parameters included: (i) the heat treatment temperature within the range of 800-1100°C; (ii) different milling extents of calcined powders; (iii) the liquid-to-powder ratio (LPR); (iv) the use of powder blends with different particle sizes (PS) and particle size distributions (PSD); (v) the partial replacement of fine powders by large spherical dense granules prepared via freeze granulation method to simulate coarse individual particles. The aim was contributing to better understanding of the effects of PS, PSD, morphology and state of aggregation of the starting powders on injectability of pastes produced thereof. Powders heat treated at 800 and 1000°C with different morphologies but with similar apparent PSD curves obtained by milling/blending originated completely injectable reactive cement pastes at low LPR. This contrasted with non-reactive systems prepared thereof under the same conditions. Hypotheses were put forward to explain why the injectability results collected upon extruding non-reactive pastes cannot be directly transposed to reactive systems. The results obtained underline the interdependent roles of the different powder features and ionic strength in the liquid media on determining the flow and injectability behaviours.

Polymerisation of Kraft lignin from black liquors by laccase from Myceliophthora thermophila: effect of operational conditions and black liquor origin

The capacity of laccase from Myceliophthora thermophila to promote the oxidative polymerisation of Kraft lignin (KL) was evaluated in several conditions of pH, temperature, enzyme dosage and treatment time. Moreover, different black liquors from the Kraft cooking of Eucalyptus globulus and mixture of Pinus pinaster/E. globulus were evaluated in order to determine the effect of the KL source on the polymerisation reaction. Furthermore, one of these black liquors was fractionated by sequential organic solvent fractionation and the polymerisation of the corresponding fractions was tested. Polymerisation products were analysed by size exclusion chromatography and Fourier transform infrared spectroscopy. The results provide evidence of notable lignin modifications after incubation with laccase. Structural oxidation and a notably molecular weight increase were attained, reaching a polymer of 69-fold its initial molecular weight depending on the raw lignin. Moreover, optimum values of reaction conditions were obtained: pH 7.3, 70°C, 2UmL(-1) and 2h.

Enzymatic polymerisation and effect of fractionation of dissolved lignin from Eucalyptus globulus Kraft liquor

The potential ability of the laccase from Myceliophthora thermophila, either alone or with low molecular weight (LMW) additives, to polymerise a dissolved lignin from Kraft liquor of eucalypt cooking was investigated. A previous study of enzymatic performance (activity and stability) was carried out using a design experiment methodology. In addition, Kraft dissolved lignin (KDL) was fractionated according to two different protocols (solvent extraction and acidic fractionation) in order to identify possible lignin fractions with noticeable polymerisation ability. KDL and its corresponding lignin fractions were treated with laccase and analysed by size exclusion chromatography and Fourier transform infrared spectroscopy. The results provide conclusive evidence of notable lignin modifications after incubation with laccase. Moreover, lignin fractionation allows to obtain lignin fractions with different chemical characteristics and polymerisation capability. Depending on the type of raw lignin, molecular weight can increase from 4- to 21-fold by means of laccase polymerisation.

Differential Effects of Oral β Blockade on Cardiovascular and Sympathetic Regulation

In patients with hypertension, β blockade decreases muscle sympathetic nerve activity (MSNA; micrographic technique) expressed in burst frequency (burst/min) but does not affect MSNA expressed in burst incidence (burst/100 heart beats), because reductions in blood pressure (BP) upon each diastole continue to deactivate the arterial baroreceptors, but at a slower heart rate (HR). We studied the effects of oral β blockade on MSNA and baroreflex sensitivity (BRS) in normal participants. Bisoprolol (5 mg, 1 week) was administered in 10 healthy young adults, using a double-blind, placebo-controlled, randomized cross-over study design. The beat-to-beat mean RR interval (RR) and systolic blood pressure (SBP) series were analyzed by power spectral analysis and power computation over the very low frequency (VLF), low frequency, and high frequency (HF) bands. Baroreflex sensitivity was computed from SBP and RR cross-analysis, using time and frequency domain methods.

Bisoprolol increased RR (P < .0005), decreased mean SBP and diastolic blood pressure values (P < .01), did not change the SBP and RR powers, except for RR power in VLF (P < .02) and SBP power in HF (P < .03). The MSNA variability (P > .13) and respiratory pattern (P = .84) did not change from placebo to bisoprolol condition. The bisoprolol-induced bradycardia was associated with higher burst/100 heart beats (P < .05) and bisoprolol did not affect burst/min (P = .80). Time domain BRS estimates were increased after bisoprolol (P < .05), while frequency domain ones did not change (P > .1).

Oral bisoprolol induces differential effects on sympathetic burst frequency and incidence in normal participants. Peripheral sympathetic outflow over time is preserved as a result of an increased burst incidence, in the presence of a slower HR. Unchanged BP and HR and MSNA variability suggests that the larger burst incidence is not due to sympathetic activation.

Removal of organic pollutants and heavy metals in soils by electrokinetic remediation

In this work, the feasibility of electrokinetic remediation for the restoration of polluted soil with organic and inorganic compounds had been development and evaluated using a model soil sample. The model soil was prepared with kaolinite clay artificially polluted in the laboratory with chromium and an azo dye: Reactive Black 5 (RB5). The electromigration of Cr in a spiked kaolinite sample was studied in alkaline conditions. Despite of the high pH registered in the kaolinite sample (around pH 9.5), Cr migrated towards the cathode and it was accumulated in the cathode chamber forming a white precipitate. The removal was not complete, and 23% of the initial Cr was retained into the kaolinite sample close to the cathode side. The azo dye RB5 could be effectively removed from kaolinite by electrokinetics and the complete cleanup of the kaolinite could be achieved in alkaline environment. In this condition, RB5 formed an anion that migrated towards the anode where it was accumulated and quickly degraded upon the electrode surface. The electrokinetic treatment of a kaolinite sample polluted with both Cr and RB5 yielded very good results. The removal of Cr was improved compared to the experiment where Cr was the only pollutant, and RB5 reached a removal as high as 95%. RB5 was removed by electromigration towards the anode, where the dye was degraded upon the surface of the electrode by electrochemical oxidation. Cr was transported towards the cathode by electromigration and electroosmosis. It is supposed that the interaction among RB5 and Cr into the kaolinite sample prevented premature precipitation and allow Cr to migrate and concentrate in the cathode chamber.

Electromigration of Mn, Fe, Cu and Zn with citric acid in contaminated clay

Metal reactivity, speciation and solubility have an important influence in its transportation through a porous matrix by electrokinetics and, therefore, they dramatically affect the removal efficiency. This work deals with the effect of solubility and transport competition among several metals (Mn, Fe, Cu and Zn) during their transport through polluted clay. The unenhancement electrokinetic treatment results in a limited removal of the tested metals because they were retained into the kaolinite sample by the penetration of the alkaline front. Metals showed a removal degree in accordance with the solubility of the corresponding hydroxide and its formation pH. In 7 days of treatment, the removal results were: 75.6% of Mn; 68.5% of Zn, 40.6% of Cu and 14.8% of Fe. In order to avoid the negative effects of the basic front generated at the cathode, two different techniques were proposed and tested: the addition of citric acid as complexing agent to the polluted kaolinite sample and the use of citric acid to control de pH on the cathode chamber. Both techniques are based on the capability of citric acid to act as a complexing and neutralizing agent. Almost complete removal of Mn, Cu and Zn was achieved when citric acid was used (as neutralizing or complexing agent). But Fe only reached 33% of removal because it formed a negatively charged complex with citrate that retarded its transportation to the cathode.

Remediation of phenanthrene from contaminated kaolinite by electroremediation-Fenton technology

Polycyclic aromatic hydrocarbons (PAHs) cause a high environmental impact when released into the environment. The objective of this study was to evaluate the capacity to decontaminate polluted soils with phenanthrene as a model PAH using a combination of two technologies: electrokinetic remediation and Fenton process. Kaolinite was used as a model sample that was artificially polluted at the laboratory at an initial concentration of phenanthrene of 500 mg kg(-1) of dried kaolinite. The standard electrokinetic process resulted in negligible removal of phenanthrene from the kaolinite sample. Faster and more efficient degradation of this compound can be promoted by introduction of a strong oxidant into the soil such as hydroxyl radicals. For this reason, the Fenton reactions have been induced in several experiments in which H(2)O(2) (10%) was used as flushing solution, and kaolinite polluted with iron was used. When anode and cathode chambers were filled with H(2)O(2) (10%), the kaolinite pH is maintained at an acid value around 3.5 without pH control and an overall removal and destruction efficiency of phenanthrene of 99% was obtained in 14 days by applying a voltage gradient of 3 V cm(-1). Therefore, it is evident that a combined technology of electrokinetic remediation and Fenton reaction is capable of simultaneously removing and degrading of PAHs in polluted model samples with kaolinite.

Genomic comparisons and Shiga toxin production among Escherichia coli O157:H7 isolates from a day care center outbreak and sporadic cases in southeastern Wisconsin

Contour-clamped homogeneous electric field pulsed-field gel electrophoresis (CHEF-PFGE) was used to compare Wisconsin isolates of Escherichia coli O157:H7, including 39 isolates from a 1994 day care center outbreak, 28 isolates from 18 individuals from the surrounding geographic area with sporadic cases occurring during the 3 months before the outbreak, and 3 isolates, collected in 1995, from patients with hemolytic-uremic syndrome (HUS) who were from eastern Wisconsin counties other than those inhabited by the day care center and sporadic-case individuals. The technique of CHEF-PFGE using XbaI identified seven highly related restriction endonuclease digestion profiles (REDPs) (93 to 98% similarity) among the 39 day care center isolates and nine XbaI REDPs (63 to 93% similarity) among the 28 isolates from sporadic-case individuals, including REDP 33, which was exhibited by both day care and sporadic-case isolates. PFGE analyses of sequential E. coli O157:H7 isolates from symptomatic day care center attendees revealed that the REDPs of 25 isolates from eight patients were indistinguishable whereas the REDPs of 2 of 6 isolates from two patients differed slightly (93 to 95% similarity). The REDPs of the three isolates from 1995 HUS patients were 78 to 83% similar, with REDP 26 being exhibited by one HUS-associated isolate and an isolate from one day care attendee who did not develop HUS. The genes for both Shiga toxins I and II (stx1 and stx2, respectively) were detected in all but one isolate (sporadic case), and Shiga toxin production by the day care center isolates was not significantly different from that of the other isolates, including the three HUS-associated isolates. Analyses of E. coli O157:H7 isolates from both the day care center outbreak and sporadic cases by CHEF-PFGE permitted us to define the REDP variability of an outbreak and geographic region and demonstrated that the day care center outbreak and a HUS case in 1995 were caused by E. coli O157:H7 strains endemic to eastern Wisconsin.

Nutritional homeostasis in locusts: is there a mechanism for increased energy expenditure during carbohydrate overfeeding?

Maintenance of carbohydrate balance via changes in CO2 output volume was investigated in locusts using a flow-through respirometer. The effect of an imbalance in the dietary protein to digestible carbohydrate ratio on expired CO2 levels was measured in locusts fed one of two synthetic diets [7% protein, 21% digestible carbohydrate (7:21) and 21% protein, 7% digestible carbohydrate (21:7)]. Additionally, the effect of dietary dilution was investigated by feeding locusts one of two diets with a close-to-optimal ratio of protein to carbohydrate, one containing 7% protein and 7% digestible carbohydrate (7:7) and the other containing 21% protein and 21% digestible carbohydrate (21:21). For insects fed unbalanced diets, a higher CO2 output volume was measured during feeding on diet 7:21 when compared with insects fed on diet 21:7. Locusts also expired a greater volume of CO2 during the entire 2h observation period. This response is consistent with specific metabolic control of carbohydrate balance via enhanced respiration. For insects fed balanced diets, the total volume of CO2 expired over the duration of a meal was greater for insects fed diet 7:7 than for those fed diet 21:21, although this was due entirely to meals lasting longer on the more dilute diet. However, the basal level of respiration rate was greater for insects fed diet 21:21 and, as a result, over the entire 2h period, CO2 output volume did not differ between locusts fed diet 7:7 or 21:21. A possible mechanism for enhanced CO2 output volume on the nutritionally unbalanced diet was investigated, namely triglyceride/fatty-acid substrate cycling. There was no evidence for the presence of the thermogenic effect of this particular cycle on locusts as a means for dealing with excess ingested carbohydrate.