Omicron Waves in Argentina: Dynamics of SARS-CoV-2 Lineages BA.1, BA.2 and the Emerging BA.2.12.1 and BA.4/BA.5.

The COVID-19 pandemic has lately been driven by Omicron. This work aimed to study the dynamics of SARS-CoV-2 Omicron lineages during the third and fourth waves of COVID-19 in Argentina. Molecular surveillance was performed on 3431 samples from Argentina, between EW44/2021 and EW31/2022. Sequencing, phylogenetic and phylodynamic analyses were performed. A differential dynamic between the Omicron waves was found. The third wave was associated with lineage BA.1, characterized by a high number of cases, very fast displacement of Delta, doubling times of 3.3 days and a low level of lineage diversity and clustering. In contrast, the fourth wave was longer but associated with a lower number of cases, initially caused by BA.2, and later by BA.4/BA.5, with doubling times of about 10 days. Several BA.2 and BA.4/BA.5 sublineages and introductions were detected, although very few clusters with a constrained geographical distribution were observed, suggesting limited transmission chains. The differential dynamic could be due to waning immunity and an increase in population gatherings in the BA.1 wave, and a boosted population (for vaccination or recent prior immunity for BA.1 infection) in the wave caused by BA2/BA.4/BA.5, which may have limited the establishment of the new lineages.

The effect of preoperative clindamycin in reducing early oral implant failure: a randomised placebo-controlled clinical trial.

OBJECTIVES: To assess the effect of preoperative oral clindamycin in reducing early implant failure in healthy adults undergoing conventional implant placement. MATERIALS AND METHODS: We conducted a prospective, randomised, double-blind, placebo-controlled clinical trial in accordance with the ethical principles and Consolidated Standards of Reporting Trials statement. We included healthy adults who underwent a single oral implant without previous infection of the surgical bed or the need for bone grafting. They were randomly treated with a single dose of oral clindamycin (600 mg) 1 h before surgery or a placebo. All surgical procedures were performed by one surgeon. A single trained observer evaluated all patients on postoperative days 1, 7, 14, 28, and 56. Early dental implant failure was defined as the loss or removal of an implant for any reason. We recorded the clinical, radiological, and surgical variables, adverse events, and postoperative complications. The study outcomes were statistically analysed to evaluate differences between the groups. Furthermore, we calculated the number required to treat or harm (NNT/NNH). RESULTS: Both the control group and clindamycin group had 31 patients each. Two implant failures occurred in the clindamycin group (NNH = 15, p = 0.246). Three patients had postoperative infections, namely two placebo-treated and one clindamycin-treated, which failed (relative risk: 0.5, CI: 0.05-5.23, absolute risk reduction = 0.03, confidence interval: - 0.07-0.13, NNT = 31, CI: 7.2-∞, and p = 0.5). One clindamycin-treated patient experienced gastrointestinal disturbances and diarrhoea. CONCLUSIONS: Preoperative clindamycin administration during oral implant surgery in healthy adults may not reduce implant failure or post-surgical-complications. CLINICAL RELEVANCE: Oral clindamycin is not efficacy. TRIAL REGISTRATION: The present trial was registered (EudraCT number: 2017-002,168-42). It was approved by the Committee for the Ethics of Research with Medicines of Euskadi (CEIm-E) on 31 October 2018 (internal code number: 201862) and the Spanish Agency of Medicines and Medical Devices (AEMPS) on 18 December 2018.

Evolution of SARS-CoV-2 during the first year of the COVID-19 pandemic in Northwestern Argentina.

Studies about the evolution of SARS-CoV-2 lineages in different backgrounds such as naive populations are still scarce, especially from South America. This work aimed to study the introduction and diversification pattern of SARS-CoV-2 during the first year of the COVID-19 pandemic in the Northwestern Argentina (NWA) region and to analyze the evolutionary dynamics of the main lineages found. In this study, we analyzed a total of 260 SARS-CoV-2 whole-genome sequences from Argentina, belonging to the Provinces of Jujuy, Salta, and Tucumán, from March 31st, 2020, to May 22nd, 2021, which covered the full first wave and the early second wave of the COVID-19 pandemic in Argentina. In the first wave, eight lineages were identified: B.1.499 (76.9%), followed by N.5 (10.2%), B.1.1.274 (3.7%), B.1.1.348 (3.7%), B.1 (2.8%), B.1.600 (0.9%), B.1.1.33 (0.9%) and N.3 (0.9%). During the early second wave, the first-wave lineages were displaced by the introduction of variants of concern (VOC) (Alpha, Gamma), or variants of interest (VOI) (Lambda, Zeta, Epsilon) and other lineages with more limited distribution. Phylodynamic analyses of the B.1.499 and N.5, the two most prevalent lineages in the NWA, revealed that the rate of evolution of lineage N.5 (7.9 × 10-4 substitutions per site per year, s/s/y) was a ∼40% faster than that of lineage B.1.499 (5.6 × 10-4 s/s/y), although both are in the same order of magnitude than other non-VOC lineages. No mutations associated with a biological characteristic of importance were observed as signatures markers of the phylogenetic groups established in Northwestern Argentina, however, single sequences in non-VOC lineages did present mutations of biological importance or associated with VOCs as sporadic events, showing that many of these mutations could emerge from circulation in the general population. This study contributed to the knowledge about the evolution of SARS-CoV-2 in a pre-vaccination and without post-exposure immunization period.

Estimate of activity discharged into the sewer network in neuroendocrine treatments with 177Lu-DOTA-TATE.

The urine of patients treated for neuroendocrine tumors with 177Lu is a liquid radioactive waste. The total body activity retained by the patient is quantified with SPECT-CT image 1 day after administration. From the activity of 177Lu in patient after 1 day Apat_Lu177_1d, the activity in urine after 1 day Aurine_Lu177_1d is determined, as well as the activity of 177mLu Aurine_Lu177m_1d that accompanies 177Lu as an impurity. Admitting the patient 24 hours in a dedicated room with storage tanks reduces the discharged activity below the permitted limits.

Antimicrobial Mechanisms of Leucocyte- and Platelet Rich Fibrin Exudate Against Planktonic Porphyromonas gingivalis and Within Multi-Species Biofilm: A Pilot Study.

Leucocyte- and platelet rich fibrin (L-PRF) is an autologous biomaterial used in regenerative procedures. It has an antimicrobial activity against P. gingivalis although the mechanism is not fully understood. It was hypothesized that L-PRF exudate releases hydrogen peroxide and antimicrobial peptides that inhibit P. gingivalis growth. Agar plate and planktonic culture experiments showed that the antimicrobial effect of L-PRF exudate against P. gingivalis was supressed by peroxidase or pepsin exposure. In developing multi-species biofilms, the antimicrobial effect of L-PRF exudate was blocked only by peroxidase, increasing P. gingivalis growth with 1.3 log genome equivalents. However, no effect was shown on other bacteria. Pre-formed multi-species biofilm trials showed no antimicrobial effect of L-PRF exudate against P. gingivalis or other species. Our findings showed that L-PRF exudate may release peroxide and peptides, which may be responsible for its antimicrobial effect against P. gingivalis. In addition, L-PRF exudate had an antimicrobial effect against P. gingivalis in an in vitro developing multi-species biofilm.

Efficacy of a Coriolus versicolor-Based Vaginal Gel in Women With Human Papillomavirus-Dependent Cervical Lesions: The PALOMA Study.

OBJECTIVE: The aim of the study was to evaluate the efficacy of Papilocare, a Coriolus versicolor-based vaginal gel, in repairing human papillomavirus (HPV)-related low-grade cervical lesions. METHODS: The study is a multicenter, open-label, randomized, parallel-group, watchful waiting approach-controlled trial involving 91 HPV-positive women with low-grade Pap smear alterations and consistent colposcopy. RESULTS: The percentage of patients with normal Pap smear and concordant colposcopy 3 and 6 months after receiving treatment (78.0% and 84.9%) was significantly higher than without treatment (54.8% and 64.5%), especially in high-risk HPV patients (79.5% and 87.8% vs 52.0% and 56.0%). At 6-month visit, overall HPV clearance was achieved by a greater number of patients receiving treatment (59.6%) compared with those without treatment (41.9%), especially high-risk HPV ones (62.5% vs 40.0%). The cervical re-epithelization score was significantly higher with treatment (mean = 4.5) than without (mean = 4.1). Compared with baseline, perceived stress decreased in the treatment group (from 21.1 to 19.0) and increased in the control group (from 17.7 to 20.7). A total of 7 possible or probable treatment-related adverse events were reported, most of them (n = 6) being mild or moderate in severity. CONCLUSIONS: Treatment with Papilocare has demonstrated a better clinical benefit than the conventional watchful waiting approach in clinical practice for total and high-risk HPV patients in terms of its efficacy to treat HPV-related cervical lesions and to clear all HPV strains after a single 6-month period. It has demonstrated an adequate safety and tolerability and confers additional benefits such as higher re-epithelization, stress reduction, and high treatment adherence.

Antibiotic dosage prescribed in oral implant surgery: A meta-analysis of cross-sectional surveys.

This study aimed to assess the dosage and types of antibiotics prescribed in oral implant surgery, compare them among the different subpopulations (country and prescription regimens) and against the evidence-based recommended dosage: a 2-gram single preoperative dose of amoxicillin. A meta-analysis of cross-sectional surveys was conducted, which reports the overall dosage (and type) of antibiotics prescribed in combination with implant placement. PubMed, Cochrane, Science, Direct, and EMBASE via OVID were searched until April 2019. Three reviewers independently undertook data extraction and risk of bias assessment. The outcome variable was set on the average of prophylactic antibiotics prescribed per oral implant surgery. Overall, 726 participants from five cross-sectional surveys, representing five different countries were finally included. Amoxicillin was the most prescribed antibiotic. On average, 10,724 mg of antibiotics were prescribed per implant surgery. This average was significantly (p<0.001) higher than 2,000 mg. Overall, amoxicillin doses were significantly higher than 2,000 mg (9,700 mg, p<0.001). All prescribed amoxicillin regimens independently contained more than 2,000 mg, including those comprising only preoperative amoxicillin (2,175 mg, p = 0.006). Exclusive preoperative antibiotic regimens were the only subgroup with prescription dosages below this threshold (p = 0.091). Significant variations in antibiotic prescriptions were found among different countries and antibiotic regimens (p<0.001). In conclusion, the average dose of antibiotics prescribed per oral implant surgery was larger than the evidence-based recommended dose in healthy patients and straightforward conditions. In addition, variations in the average antibiotic dosages were found among different countries and prescription regimens.

Antibiotic prophylaxis prescribing habits in oral implant surgery in the Netherlands: a cross-sectional survey.

BACKGROUND: There seems to be no consensus on the prescription of prophylactic antibiotics in oral implant surgery. The Dutch Association of Oral Implantology (NVOI) guidelines do not include a clear policy on prophylactic antibiotic prescriptions for oral implant surgery among healthy patients. The purpose of the study was to determine whether antibiotic prophylaxis is commonly prescribed in the Netherlands by general dentists, maxillofacial surgeons and oral implantologists in conjunction with oral implant surgery among healthy patients and to assess the type and amount of prophylactic antibiotic prescribed. METHODS: This observational cross-sectional study is based on a web survey. A questionnaire developed in the United States of America was translated and slightly adjusted for use in the Netherlands. It contained predominantly close-ended questions relating to demographics, qualifications, antibiotic type, prescription duration and dosage. An email including an introduction to the study and an individual link to the questionnaire was sent in February 2018 to a sample of 600 general dental practitioners and all 302 specialized dentists (oral implantologists, periodontists and maxillofacial surgeons) recognized by the NVOI. Overall, 902 questionnaires were anonymously sent. Finally, 874 potential participants were reached. Collected data were analyzed through descriptive statistics. RESULTS: In total, 218 (24.9%) participants responded to the questionnaire, including 45 females (20.8%) and 171 males (79.2%). Overall, 151 (69.9%) regularly placed oral implants. Of them, 79 (52.7%) prescribe antibiotics only in specific situations, 66 (43.7%) regularly, and 5 (3.3%) did not prescribe antibiotics at all. Overall, 83 participants who prescribe antibiotics did so both pre- and postoperatively (57.2%), 47 only preoperatively (32.4%) and 12 exclusively postoperatively (8.3%). A single dose of 2000 mg of amoxicillin orally one hour prior to surgery was the most prescribed preoperative regimen. The most frequently prescribed postoperative regimen was 500 mg of amoxicillin three times daily for five days after surgery. On average, participants prescribe a total of 7018 mg of antibiotics before, during or after oral implant surgery. CONCLUSIONS: Antibiotic prophylaxis in conjunction with oral implant surgery is prescribed in the Netherlands on a large scale, and recommendations based on the last published evidence are frequently not followed.

Antibiotic prophylaxis habits in oral implant surgery among dentists in Italy: a cross-sectional survey.

BACKGROUND: The prescription of prophylactic antibiotics in conjunction with oral implant surgery remains inconsistent among different populations of dentists. The main objective of this study was to assess the current antibiotic prescribing habits of dentist in conjunction with oral implant surgery in Italy. The secondary objective was to assess the nature and amount (mg) of antibiotics prescriptions in order to evaluate whether any consensus has been reached and if the current recommendations are complied. METHODS: Observational cross-sectional study based on a web-survey reported according to the STROBE guidelines. A questionnaire was sent via email to each registered member of the Italian Academy of Osseointegration (n = 400). The email included a link to the anonym web questionnaire developed on www.encuestafacil.com. It contained close-ended and some open-ended questions concerning demographics, antibiotic type, prescription duration and dosage. Collected data were analyzed using STATA® 14 software. RESULTS: 160 participants responded the survey (response rate = 40%). Approximately 84% routinely prescribed prophylactic antibiotics in conjunction with oral implant surgery, 15.6% prescribed antibiotics in certain situations and only 1 did not prescribe antibiotics at all. Overall, 116 respondents prescribed both pre- and postoperative antibiotics, 29 prescribed antibiotics only preoperatively and 14 prescribed antibiotics exclusively after surgery. Italian dentists prescribed an average amount of 10,331 mg antibiotics before, during or after oral implant surgery. Approximately, only 17% (n = 27) of the participants who prescribed antibiotics before oral implant surgery complied with the recommendations proposed by the latest publications (no more than 3 g of preoperative amoxicillin before oral implant surgery). CONCLUSIONS: Dentists in Italy on a large scale prescribe antibiotic prophylaxis in conjunction with oral implant surgery among healthy patients. A high range of prophylactic regimens is prescribed and they are not adhering to the new science-based specifications. Guidelines focused on the indications for prophylactic antibiotics among healthy patients are required to prevent bacterial resistance, side effects and costs caused by overtreatment and the irrational use of antibiotics.

Diagnosis and gestational follow-up in a patient with Herlyn-Werner-Wünderlich syndrome, a case report.

OBJECTIVE: Herlyn-Werner-Wünderlich syndrome (HWW) is a rare congenital malformation of the urogenital tract due to a fusion failure in the Müllerian ducts. This anomaly consists of a didelphus uterus with obstructed hemivagina and sometimes associated with ipsilateral renal agenesis. The treatment of choice is surgical, it consists of a simple procedure of resection of the vaginal septum and drainage of the obstructed hemivagina and retained collections. CASE REPORT: We report the case of a pregnancy in a 37-year-old woman with SHWW without resection of the vaginal septum. CONCLUSIONS: The early detection is important due to the possible associated complications. Women with uterine defects are subject to an increased risk of complications in pregnancy and childbirth. Therefore, each case must be treated individually.

Antibiotic prophylaxis habits in dental implant surgery among dentists in Spain. A cross-sectional survey

BACKGROUND: The use of antibiotics to prevent dental implant failures and postoperative infections remains a controversial issue. The objectives of this study were to assess the current antibiotic prescribing patterns and antibiotic prescribing frequency of dentists in Biscay (Spain) in conjunction with routine dental implant surgery among healthy patients and to determine whether any consensus has been reached by such practitioners and last published evidence was being followed. MATERIAL AND METHODS: Observational cross-sectional study: electronic survey. This study was reported according to the STROBE guidelines. This anonymous questionnaire contained open-ended and close-ended questions. An email was sent 26 October 2017 to all the registered members of the Biscay dentists' College (n=989). The collected data were analyzed using STATA(R) 14 software, and 95% confidence intervals (CI) were used to assess the frequency of prescription for each antibiotic regimen. RESULTS: The survey was responded to by a total of 233 participants (response rate=23.56%). Overall, 210 participants finished the survey completely, and 23 surveys were answered partially. The questionnaire was responded to by 122 females (58.1%) and 88 males (41.9%). Of the participants, 88% (n=207) always routinely prescribed prophylactic antibiotics in conjunction with dental implant surgery (95% CI: 84.79-92.88%). Approximately 9% (n=22) prescribed antibiotics sometimes (95% CI: 5.68-13.19%), and only 4 dentists (1.72%) never prescribed antibiotics (95% CI: 0.04-3.38%). Overall, 179 of 233 respondents prescribed both pre- and postoperative antibiotics (78.85%, 95% CI: 72.96-83.97%), 13 prescribed antibiotics only preoperatively (5.73%, 95% CI: 3.08-9.59%), and 35 prescribed antibiotics exclusively after routine dental implant surgery (15.42%, 95% CI: 10.98-20.78%). CONCLUSIONS: Most of the dentists working in Biscay routinely prescribe prophylactic antibiotics in conjunction with dental implant surgery among healthy patients. A large range of prophylactic regimens are prescribed and the most recently published evidence is not being followed

Evolutionary dynamics of Hepatitis C virus in a chronic HIV co-infected patient and its correlation with the immune status.

The HCV evolutionary dynamics play a key role in the infection onset, maintenance of chronicity, pathogenicity, and drug resistance variants fixation, and are thought to be one of the main caveats in the development of an effective vaccine. Previous studies in HCV/HIV co-infected patients suggest that a decline in the immune status is related with increases in the HCV intra-host genetic diversity. However, these findings are based on single point sequence diversity measures or coalescence analyses in several virus-host interactions. In this work, we describe the molecular evolution of HCV-E2 region in a single HIV-co-infected patient with two clearly defined immune conditions. The phylogenetic analysis of the HCV-1a sequences from the studied patient showed that he was co-infected with three different viral lineages. These lineages were not evenly detected throughout time. The sequence diversity and coalescence analyses of these lineages suggested the action of different evolutionary patterns in different immune conditions: a slow rate, drift-like process in an immunocompromised condition (low levels of CD4+ T lymphocytes); and a fast rate, variant-switch process in an immunocompetent condition (high levels of CD4+ T lymphocytes).

Does chlorhexidine reduce bacteremia following tooth extraction? A systematic review and meta-analysis.

BACKGROUND AND AIMS: Scientific evidence is not clear regarding the use of antimicrobial mouth rinse before dental extraction to reduce bacteremia. We tested the null hypothesis that there would be no difference in the incidence of bacteremia following dental extractions in patients treated with or without chlorhexidine. MATERIAL AND METHODS: We conducted a meta-analysis following the recommendations proposed by PRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The data sources Pubmed, Cochrane, Web of Science, Science Direct, Scopus, and Ovid MD were searched until April 30, 2017. (chlorhexidine) AND (bacteremia OR bacteraemia) AND (extraction OR removal) were used as key words in a free-text search. Published meeting abstracts were searched. The references of each article were reviewed. We only included randomized controlled clinical trials. There were no restrictions regarding language or date of publication. The outcome measure was the incidence of the bacteremia measured within the first ten minutes post-extraction. Two reviewers independently undertook the risk of bias assessment and data extraction. A fixed-effects inverse variance weighted meta-analysis was conducted. RESULTS: Out of 18 studies, eight eligible trials with 523 participants were selected, 267 in the experimental group and 256 in the control group: risk ratio = 0.882 (95% confidence interval 0.799 to 0.975; p = 0.014), heterogeneity I2 = 13.07%, and p = 0.33. The number needed to treat was 16 (95% CI 7-Infinity). CONCLUSIONS: Approximately 12% of bacteremia cases can be prevented if a population is exposed to chlorhexidine. CRD42016046586.

Which antibiotic regimen prevents implant failure or infection after dental implant surgery? A systematic review and meta-analysis.

OBJECTIVE: To assess which antibiotic regimen prevents dental implant failures or postoperative infections following dental implant placement. MATERIALS AND METHODS: Systematic review and meta-analysis. DATA SOURCES: Pubmed, Cochrane, Science Direct, and EMBASE via OVID were searched up to August 2017. Only randomized controlled clinical trials (RCT) using antibiotics were included. Outcome measures were set on dental implant failures or postoperative infection incidence after dental implant surgery. Three reviewers independently undertook risk of bias assessment and data extraction. Stratified meta-analyses of binary data using fixed-effects models were performed using Stata 14.0. The risk ratio (RR) and 95% confidence interval (CI) were estimated. RESULTS: Nine articles were included corresponding to 15 RCTs. All RCTs tested only oral amoxicillin. Implant-failure analysis: overall RR = 0.53 (P = .005, 95% CI: 0.34-0.82) and overall NNT = 55 (95% CI, 33-167). Single-dose oral amoxicillin preoperatively (SDOAP) is beneficial (RR = 0.50, CI: 0.29-0.86. P = .012), when compared to postoperative oral amoxicillin (POA): RR = 0.60, CI: 0.28-1.30. P = .197. Postoperative-infection analysis: overall RR = 0.76 (P = 0.250, 95% CI: 0.47-1.22). Neither SDOAP (RR = 0.82, CI = 0.46-1.45, P = .488) nor POA (RR = 0.64, CI = 0.27-1.51, P = .309) are beneficial. I2 = 0.0%, chi-squared tests P ≈ 1. CONCLUSION: Only SDOAP is effective and efficacious at preventing implant failures, but it was not significant for postoperative infections following dental implant surgeries.

Dosimetric impact in the dose-volume histograms of rectal and vesical wall contouring in prostate cancer IMRT treatments.

AIM: The main purpose of this study was to evaluate the differences in dose-volume histograms of IMRT treatments for prostate cancer based on the delineation of the main organs at risk (rectum and bladder) as solid organs or by contouring their wall. BACKGROUND: Rectum and bladder have typically been delineated as solid organs, including the waste material, which, in practice, can lead to an erroneous assessment of the risk of adverse effects. MATERIALS AND METHODS: A retrospective study was made on 25 patients treated with IMRT radiotherapy for prostate adenocarcinoma. 76.32 Gy in 36 fractions was prescribed to the prostate and seminal vesicles. In addition to the delineation of the rectum and bladder as solid organs (including their content), the rectal and bladder wall were also delineated and the resulting dose-volume histograms were analyzed for the two groups of structures. RESULTS: Data analysis shows statistically significant differences in the main parameters used to assess the risk of toxicity of a prostate radiotherapy treatment. Higher doses were received on the rectal and bladder walls compared to doses received on the corresponding solid organs. CONCLUSIONS: The observed differences in terms of received doses to the rectum and bladder based on the method of contouring could gain greater importance in inverse planning treatments, where the treatment planning system optimizes the dose in these volumes. So, one should take into account the method of delineating of these structures to make a clinical decision regarding dose limitation and risk assessment of chronic toxicity.

La prevención del cáncer ginecológico en la asistencia privada / Prevention of gynecologic cancer in private assistance

Están definidos dos escenarios para la aplicación de las estrategias preventivas de un cáncer, los que se desarrollan en el ámbito de las iniciativas de salud pública y aquellos que se circunscriben a la actividad asistencial personalizada. Saber dónde estamos trabajando y no mezclar estos ámbitos preventivos es imprescindible para alcanzar bien los objetivos, que son diferentes en su ambición, por lo que en su consecución, en pura lógica, deberán ser usadas metodologías también diferentes. A continuación detallamos las que en opinión de los firmantes podrían ser los modelos de conducta a seguir en la actividad asistencial personalizada enfocados a la prevención de los cánceres ginecológicos (AU)

Two scenarios are defined for the application of preventive strategies of cancer, those developed within the scope of public health initiatives and those that are confined to the personalized care activity. Knowing where we are working and not mixing these preventive areas is essential to achieve the objectives properly, which are different in their ambition, so that in their pursuit, in pure logic, there should be used different methodologies. Next are detailed, in the opinion of the signatories, which could be the models of conduct to be followed in the personalized care activity focused on the prevention of gynecological cancers (AU)

Does Chlorhexidine Prevent Alveolar Osteitis After Third Molar Extractions? Systematic Review and Meta-Analysis.

PURPOSE: The prevention of alveolar osteitis (AO) in dental extractions remains a controversial issue. Chlorhexidine is one of the most widely studied antiseptics for the prevention of AO. The purpose of this systematic review and meta-analysis was to assess the efficacy and effectiveness of chlorhexidine in the prevention of AO after third molar extractions. MATERIALS AND METHODS: The authors searched databases and the references of each article retrieved up to December 2015. Clinical randomized controlled trials (RCTs) using only chlorhexidine were included. The predictor variable was whether chlorhexidine was used in any formulation, concentration, or regimen. The outcome measurement was the incidence of postoperative AO. The authors also recorded variables describing the characteristics of the included studies. Statistical analysis was performed using STATA 12.0. Meta-analysis of binary data was conducted using a fixed-effects model. Risk ratios and 95% confidence intervals (CIs) were estimated. Forest, l'Abbé, and funnel plots were constructed. RESULTS: Twenty-three studies published from 1979 to 2015, corresponding to 18 trials (16 parallel-group and 2 split-mouth RCTs), that reported on 2,824 third molar extractions (1,458 in experimental group and 1,366 in control group) were included. The overall relative risk (RR) was 0.53 (95% CI, 0.45-0.62; P < .0001). There was no evidence of heterogeneity (I2 = 9.3%; P = .336 by χ2 test). The number needed to treat was 8 (95% CI, 7-11). There were no relevant differences between chlorhexidine rinse (RR = 0.58; 95% CI, 0.47-0.71) and gel (RR = 0.47; 95% CI, 0.37-0.60). Chlorhexidine did not cause a larger proportion of adverse reactions than placebo. CONCLUSION: The use of chlorhexidine, in any formulation, concentration, or regimen, is efficacious and effective in preventing AO in patients who have undergone third molar extraction. Chlorhexidine gel was found to be moderately more efficacious than the rinse formulation.

Changing epidemiology of hepatitis C virus genotypes in the central region of Argentina.

The aim of this study was to analyze the prevalence of hepatitis C virus (HCV) genotypes in Córdoba province, Argentina, over a 12-year period and to study the changes at the molecular level. The HCV genotype was determined in 357 HCV-infected patients, and the phylogeny and demographic reconstruction for HCV-1 was assessed. A significant reduction in HCV-2 prevalence with respect to HCV-1 in Córdoba after 2003 was observed. These findings are consistent with the epidemiological changes observed in South America. Nevertheless, the consequences of these changes remain to be elucidated.

Genetic characterization and clinical implications of human papillomavirus type 16 (HPV16) variants from northeastern Argentina.

BACKGROUND: Human papillomavirus type 16 (HPV16) plays a central role in the development of cervical cancer. Worldwide studies indicate the existence of HPV16 variants that show different geographic distributions and oncogenic potential. OBJECTIVE: Our goal was to describe the genetic variation of HPV16 isolates identified in urban women with different grades of cervical lesions living in northeastern Argentina. STUDY DESIGN: We analyzed 116 HPV16-positive cervical samples (16 NLIM, 62 L-SIL, 16 H-SIL and 22 cervical cancer) from patients attending health centers in Misiones (Argentina) during 2006-13. HPV16 isolates were genetically characterized through PCR amplification and direct sequencing of 364 bp within the long control region, and the resulting sequences classified into variants based on phylogenetic analysis (lineages A, B, C and D). A potential association between HPV16 variants and lesion grade was evaluated through an odds ratio (OR) test. A temporal framework for the origin of HPV16 variants was assessed through coalescence analysis (BEAST v 1.7.5). RESULTS: Phylogenetic analysis of HPV16 sequences showed that 92.1% of the samples clustered with lineage A, and 6.9% to lineage D. HPV16 variants from lineage D were more frequently associated with high-grade lesions and cancer (HSIL+) than lineage A variants at an OR of 13.8 (1.6-117.0). The time to most common recent ancestor (tMCRA) of all variants was 119,103 years before present (HPD 95%=48,486-197,239), a date consistent with the time frame for modern human evolution. CONCLUSION: Our results suggest that HPV16 variants from lineage D may represent an additional risk factor for the development of cervical cancer in women living in northeastern Argentina. This study provides new information about viral isolates present in Argentina that will contribute to the monitoring of HPV16 infection in the vaccine era.

Implementación de intrumentos de evaluación objetiva de competencias técnicas en cirugía / Implementation instruments objective assessment of technical skills in surgery

Introducción: La adquisición de habilidades quirúrgicas constituye un factor central en la formación de todo cirujano. Sin embargo, la evaluación de las habilidades técnicas es uno de los factores más débiles y menos desarrollados. En la actualidad los recursos para evaluar las competencias técnicas adolecen de subjetividad, falta de confiabilidad y validez. La observación directa, método de evaluación más frecuentemente utilizado en nuestro medio, presenta inconvenientes instrumentales y está fuertemente influenciada por las relaciones intersubjetivas y los rasgos de personalidad. El objetivo de esta investigación es proponer la creación y el uso de un instrumento objetivo para evaluar el desempeño técnico, y determinar su confiabilidad y validez. Materiales y métodos: se seleccionaron dos procedimientos: la colecistectomía laparoscópica y la hernioplastia inguinal (técnica de Lichtenstein). Se constituyeron tres grupos de comparación según la experiencia quirúrgica: inicial, intermedio, y expertos. Se filmaron las cirugías en tiempo real, sin identificación del paciente ni del cirujano. Las filmaciones sin edición fueron asignadas a dos cirujanos expertos en una secuencia aleatoria por sorteo y con sobres sin identificación. Para la evaluación se propuso el uso de un instrumento objetivo (explicitación de pasos a evaluar y cuantificación mediante escala de Likert) y específico para cada procedimiento. Así mismo se utilizó la escala global OSATS (R. Reznick). Se aplicó un análisis de varianza no paramétrico para determinar la validez. Valores de p menores a 0.05 fueron considerados estadísticamente significativos. Valores superiores a 0,80 del Coeficiente alfa de Cronbach aseguraron confiabilidad.

SUMMARY: Introduction: technical skills acquisition is considered to be of paramount importance in surgical training. Yet, formal assessment of technical skills is the weakest and less developed area. Currently available resources to evaluate technical skills are largely subjective, and lack of validity and reliability. Direct observation, one of the most frequently used methods, is largely biased by interpersonal subjectivity and personality traits. We propose the creation and use of a new procedure-specific tool for objective assessment of technical skills in surgery to evaluate validity and reliability. Materials and Method: laparoscopic cholecystectomy and Lichstenstein’s inguinal hernia repair were the chosen procedures. Three groups of comparison were defined according to surgical expertise: initial, intermediate, and experts. Surgeries were videorecorded in real time without identification of the patient or the surgeon. Tapes without any posterior edition were assigned to two expert surgeons in a blind and randomized sequence. A newly proposed procedure-specific rating scale was used for evaluation, as well as Reznick’s OSATS global scale. Kruskal-Wallis non-parametric test was used to assess validity. p < 0,05 was considered statistically significant. Chronbach’s α values > 0.8 granted reliability.