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Low-frequency mutations associated with drug resistance have been related to virologic failure in subjects with no history of pre-treatment and recent HIV diagnosis. In total, 78 antiretroviral treatment (ART)-naïve subjects with a recent HIV diagnosis were selected and followed by CD4+ T lymphocytes and viral load tests to detect virologic failure. We sequenced the basal samples retrospectively using next-generation sequencing (NGS), looking for low-frequency mutations that had not been detected before using the Sanger sequencing method (SSM) and describing the response to ART. Twenty-two subjects developed virologic failure (VF), and thirteen of them had at least one drug-resistance mutation associated with Reverse Transcriptase Inhibitors (RTI) and Protease Inhibitors (PIs) at frequency levels ≤ 1%, not detected previously in their basal genotyping test. No resistance mutations were observed to Integrase Strand Transfer Inhibitors (INSTIs). We identified a possible cause of VF in ART-naïve subjects with low-frequency mutations detected. To our knowledge, this is the first evaluation of pre-existing drug resistance for HIV-1 minority variants carried out on ART-naïve people living with HIV/AIDS (PLWHA) by analyzing the HIV-1 pol gene using NGS in the country.

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The aim of this study was to assess intra-arch mandibular dimensional changes that may occur during mouth opening using cone beam-computed tomography (CBCT). Fifteen patients in need of any type of treatment whose execution considered a pre- and post-CBCT assessment consented and were enrolled. CBCTs were taken with the following settings: 90 kV, 8 mA, field of view (FOV) 140 by 100 mm (height and diameter), Voxel size 0.25 mm (high resolution). The pre-CBCT was executed in the maximum mandibular opening (MO), while the post-CBCT was in the maximum intercuspation (MI). A thermoplastic stent with radiopaque fiducial markers (steel ball bearings) was fabricated for each patient. Measurements were made using radiographic markers between contralateral canines and contralateral first molars and between ipsilateral canines and first molars on both sides. Paired t-tests were performed to evaluate the difference between open and closed positions on these four measurements. In the MO position were registered a significative tightening of the mandible at the canine (-0.49 mm, SD 0.54 mm; p < 0.001) and molar points (-0.81 mm, SD 0.63 mm; p < 0.001) and a significative shortening of the mandible on the right (-0.84 mm, SD 0.80 mm; p < 0.001) and left sides (-0.87 mm, SD 0.49 mm; p < 0.001). Within the study limitations, mandibular flexure determined a significant shortening and tightening between maximum intercuspation to maximum opening positions. Mandibular dimensional changes should be considered in light of other patient factors in the treatment planning of implant positioning and long-span complete arch implant-supported fixed prostheses in order to avoid technical complications.

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OBJECTIVES: To determine the prevalence and risk factors of genital Chlamydia trachomatis (CT) among school-going sexually experienced male and female adolescents in Panama. METHODS: We conducted two multisite cross-sectional studies using two-stage cluster sampling to select adolescents aged 14-19 years attending urban public high schools (URB) in Panama City, San Miguelito, Colón and Panama Oeste from 2015 to 2018, and in the rural Indigenous Comarca Ngäbe-Buglé (CNB) from July-November 2018. CT testing was performed by real-time PCR on urine samples. Random-effects logistic regression accounting for sample clustering was used to identify risk factors. RESULTS: We enrolled 3166 participants (54.3% females), median age 17 years (IQR: 15.9-18.1), with no difference by sex. Sexual experience was reported by 1954 (61.7%) participants. Combined CT prevalence was 15.8% (95% CI: 14.2 to 17.4), with no significant differences by region (URB=16.5%, 95% CI: 14.7% to 18.6%; CNB=13.6%, 95% CI: 10.9% to 16.8%; p=0.12). In an age-and-region-adjusted analysis, CT prevalence was higher among female participants compared with males (21.6% vs 9.1%, adjusted OR (AOR)=2.87, 95% CI: 1.62 to 5.10). Among sexually experienced females, CT prevalence was higher among those who reported ≥3 lifetime sex partners compared with one partner (33.5% vs 15.3%, AOR=2.20, 95% CI: 1.09 to 4.07); and among those reporting at least one pregnancy compared with nulligravidae participants (30.9% vs 13.8%, AOR=1.89, 95% CI: 1.05 to 3.43). In unadjusted analyses among males, CT was associated with older age (11.5% among those aged 18-19 years vs 3.4% among those aged 14-15 years, OR=3.69, 95% CI: 1.10 to 12.33). CONCLUSIONS: We report high CT prevalence among sexually experienced, school-going adolescents in Panama. Female adolescents, particularly those with multiple sex partners and a history of pregnancy, were at highest risk. Adolescent-targeted CT screening should be implemented in Panama. Additionally, evidence-based comprehensive sexuality education will be imperative.

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OBJECTIVES: To investigate the effects of applying dry needling into a trigger point (TrP) or non-TrP area in people who have suffered a stroke and to investigate if the effects of dry needling are maintained at six-week follow-up. METHODS: A controlled, repeated-measures, crossover, double-blinded randomized trial was conducted. Nineteen patients with hemiparetic shoulder pain after a stroke event were randomly assigned to receive a single multimodal treatment session combined with TrP dry needling or non-TrP dry needling. The neuro-rehabilitation session included modulatory interventions targeting the central nervous system. Spasticity (Modified Ashworth Scale), shoulder pain intensity (numerical pain rate scale, 0-10), and upper extremity function (Motor Evaluation Scale for Upper Extremity in Stroke [MESUPES], Reaching Performance Scale [RPS]) were assessed before (baseline) and one, two, three, four, five, and six weeks after the treatment session by a blinded assessor. All participants received both sessions in a randomized order where they were followed up for six weeks before receiving the opposite treatment and then followed up for another six weeks. RESULTS: Changes in muscle tone (all P > 0.266) and upper extremity function (MESUPES: F = 0.544, P = 0.465; RPS close task: F = 0.820, P = 0.371; RPS far task: 0.830, P = 0.368) were similar after both interventions at all follow-up periods. The decrease in shoulder pain was higher within the TrP dry needling group as compared with the non-TrP dry needling group, particularly at two and four weeks (P = 0.01). CONCLUSIONS: The effect of dry needling on muscle tone (spasticity) and upper extremity function is not related to its application in or outside of a TrP area. The effect of dry needling on shoulder pain was slightly superior when applied over a TrP in poststroke people. These effects were maintained six weeks after treatment.

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Most of the information on clinical factors related to HIV infection is focused on key populations and young people. Therefore, there is little information on clinical factors related to HIV infection in older persons (>45 years old). In this study, data on CD4 lymphocyte counts were analyzed on adults who are linked to care and have their first CD4 cell count done from different regions of the Republic of Panama from 2012 to 2017. Samples were grouped according to late presentation status, region of origin in the country, year, gender, and age groups. Factors associated with late presentation to care and advanced HIV were assessed on each group by multivariable logistic regression. Late presentation to care was observed in 71.6% of the evaluated subjects, and advanced HIV in 54.5%. Late presentation was associated with males (adjusted odds ratio [AOR] = 1.3, 95% confidence interval [CI]=1.1-1.6, p = 0.03), age greater than 45 years old (AOR = 2.3 CI= 1.8-2.9, p < 0.001), and being from regions where antiretroviral clinics are not well instituted (AOR = 2.1, CI = 1.6-2.7, p < 0.001). Despite an increase in subjects linked to care with a CD4 test performed over the years, late presentation remained constant. Therefore, prevention policies must be reformulated. Promotion of routine HIV testing, accessibility among all population groups, installation of antiretroviral clinics, and implementation of programs as rapid initiation of antiretroviral therapy should be rolled out nationally.

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BACKGROUND: There is scant information on sexually transmitted infection (STI) prevalence and risk factors among Latin American indigenous populations. We investigated STI prevalence and risk factors among adolescents of the Comarca Ngäbe-Buglé indigenous region of Panama. METHODS: A population-based cross-sectional study was conducted among school-going adolescents aged 14 to 19 years. Eligible consenting participants self-completed a questionnaire and provided blood and urine samples. Female participants provided additional self-administered genital swabs. Seroprevalences of human immunodeficiency virus (HIV), syphilis, hepatitis B (HBsAg, anti-HBc), and herpes simplex virus type 2 (HSV-2) were determined in all participants; genital Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) by PCR among participants who reported sexual experience or were seropositive for HIV/syphilis/HSV2/HBsAg; high-risk human papillomavirus (HPV) by qualitative DNA assay and bacterial vaginosis (BV) by Gram-stain among female participants. Risk factors were identified by estimating adjusted odds ratios (AOR) using random-effects logistic regression. RESULTS: We enrolled 700 participants (median age, 17 years [female participants]; 18 years [male participants]) from 20 schools. Sexual experience was reported by 536 participants (76.6%). The HIV/STI prevalences among females and males were: HIV 0.4% and 1.0%, high-titer active syphilis 1.3% and 6.6%, HSV-2 16.1% and 16.1%, HBsAg 1.3% and 1.4%, anti-HBc 3.2% and 1.4%, NG 1.8% and 1.7%, CT 17.5% and 10.7%; among females: BV 42.9% and HPV 33.2%. CT was independently associated with being female (AOR, 2.02; 95% confidence interval [CI], 1.20-3.41); high-titer active syphilis with being male (AOR, 4.51; 95% CI, 1.17-17.40). Bacterial vaginosis was associated with sexual behavior (≥3 lifetime sex partners: AOR, 3.81; 95% CI, 1.29-11.26), HPV with sexual experience (AOR, 4.05; 95% CI, 1.62-10.09). CONCLUSIONS: School-going indigenous adolescents in rural Panama have substantial STI burden. Targeted STI screening is required.

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The Hepatitis B Virus (HBV) can cause acute or chronic infection it is also associated with the development of liver cancer, thousands of new infections occur on a yearly basis, and many of these cases are located in certain areas of the Caribbean and Latin America. In these areas, the HBV prevalence is still high which makes this virus a serious public health concern to the entire region. Studies performed in Panama suggest a complex pattern in the distribution of HBV among the country's different risk groups. We use phylogenetic analysis in order to determine which HBV genotypes were circulating in these specific groups; for this we used a fragment of the PreS2/2 region of the HBV genome. Subsequently whole HBV genome sequences were used for Bayesian analysis of phylodynamics and phylogeography. Two main genotypes were found: genotype A (54.5%) and genotype F (45.5%). There was a difference in the distribution of genotypes according to risk groups: 72.9% of high risk groups were associated to genotype A, and 55.0% of samples of genotype F were associated to the low risk group (p<0.002). The Bayesian analysis of phylogeny-traits association revealed a statistically significant geographical association (p<0.0001) with both genotypes and different regions of the country. The Bayesian time of most recent common ancestor analysis (tMRCA) revealed a recent tMRCA for genotype A2 circulating in Panama (1997, 95% HPD: 1986-2005), when it is compared with Panamanian genotype F1c sequences (1930, 95% HPD: 1810 - 2005). These results suggest a possible change in the distribution of HBV genotypes in Panama and Latin America as a whole. They also serve to encourage the implementation of vaccination programs in high-risk groups, in order to prevent an increase in the number of new HBV cases in Latin America and worldwide.

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Hepatitis B Virus (HBV) is an infectious agent that causes more than half of the cases of liver disease and cancer in the world. Globally there are around 250 million people chronically infected with this virus. Despite 16% of the cases of liver disease in Central America are caused by HBV, the information regarding its genetic diversity, genotypes and circulation is scarce. The purpose of this study was to evaluate the genetic variability of the HBV genotypes from HBV-DNA positive samples obtained from screening blood donors at the Social Security System of Panama and to estimate its possible origin. From 59,696 blood donors tested for HBV infection during 2010-2012, there were 74 HBV-DNA positive subjects. Analysis of the partial PreS2-S region of 27 sequences shows that 21% of the infections were caused by genotype A, 3% by genotype D and 76% by genotype F. In addition, we were able to confirm circulation of six sub-genotypes A1, A2, A3, D4, F3, F1 and a proposed new sub-genotype denominated F5pan. We found a confinement of sub-genotypes F1 and F5pan to the western area of Panama. The tMRCA analysis suggests a simultaneous circulation of previously described sub-genotypes rather than recent introductions of the Panamanian sub-genotypes in the country. Moreover, these results highlight the need of more intensive research of the HBV strains circulating in the region at the molecular level. In conclusion, Panama has a high HBV genotype diversity that includes a new proposed sub-genotype, an elevated number of PreCore-Core mutations, and confinement of these variants in a specific geographical location.

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Despite the effectiveness of current hepatitis B virus (HBV) vaccines, it is estimated that 350 million individuals suffer from chronic HBV infection and more than 50% of these affected individuals live on the Asian continent. Panama is a country with a great diversity of foreign groups; the Chinese community is a large example of this phenomenon. There is an urgent need to perform studies that evaluate the prevalence and the genetic diversity of HBV in this community. This study aimed to evaluate the prevalence of HBV and its genotypes and mutant variants in the Chinese population residing in Panama. In total, 320 subjects were enrolled in the study. Forty-two subjects (13.1%) were positive for HBsAg and HBV-DNA from 18 subjects revealed the presence of genotypes B2 and C1. Secondary mutations associated with drug resistance at positions rtV207L and rtN239T of the reverse transcriptase gene were identified. Additionally, the mutation pair A1762T/G1764A was found in three samples and the mutation G1896A was detected in an HBeAg-negative subject. In conclusion, to our knowledge, this is the first study to report high HBV prevalence rates in resident ethnic Chinese in Central America and the presence of genotypes B2 and C1 in this region.

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Despite the effectiveness of current hepatitis B virus (HBV) vaccines, it is estimated that 350 million individuals suffer from chronic HBV infection and more than 50% of these affected individuals live on the Asian continent. Panama is a country with a great diversity of foreign groups; the Chinese community is a large example of this phenomenon. There is an urgent need to perform studies that evaluate the prevalence and the genetic diversity of HBV in this community. This study aimed to evaluate the prevalence of HBV and its genotypes and mutant variants in the Chinese population residing in Panama. In total, 320 subjects were enrolled in the study. Forty-two subjects (13.1%) were positive for HBsAg and HBV-DNA from 18 subjects revealed the presence of genotypes B2 and C1. Secondary mutations associated with drug resistance at positions rtV207L and rtN239T of the reverse transcriptase gene were identified. Additionally, the mutation pair A1762T/G1764A was found in three samples and the mutation G1896A was detected in an HBeAg-negative subject. In conclusion, to our knowledge, this is the first study to report high HBV prevalence rates in resident ethnic Chinese in Central America and the presence of genotypes B2 and C1 in this region.

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A one-step RT-PCR and one-enzyme RFLP was used to detect and distinguish among flaviviruses, including the four serotypes of dengue and the St. Louis Encephalitis, West Nile and Yellow Fever viruses in cultured virus samples or acute-phase human serum. Using a previously described RT-PCR, but novel RFLP procedure, results are obtained in 24 h with basic PCR and electrophoresis equipment. There is 95% agreement between RT-PCR/RFLP results and those achieved by indirect immunofluorescence assays, and 100% agreement between RT-PCR/RFLP results and gene sequencing. This method is more rapid than tests of cytopathic effect based on virus isolation in tissue culture, and simpler than real-time PCR. It does not require specialized equipment, radioisotopes or computer analysis and is a method that can be applied widely in the developing world. It allows for prompt determination of whether a flavivirus is the cause of illness in a febrile patient, rapid identification of dengue serotypes in circulation, and improved patient management in cases where prior dengue exposure make dengue hemorrhagic fever or dengue shock syndrome a risk.

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OBJECTIVES: To evaluate the efficacy and safety of 2.5 mg and 5 mg mifepristone during 3 months for the treatment of uterine fibroids before surgery. DESIGN: Multicenter randomized clinical trial. LOCATIONS: Eusebio Hernández Hospital, Havana, Cuba and the Alemán Hospital, Managua, Nicaragua. SUBJECTS: Included in the study were 146 women with symptomatic uterine fibroids. TREATMENT: GROUP I: half a tablet of 5 mg (2.5 mg) mifepristone taken orally every 24 hours, and Group II: one tablet of 5 mg mifepristone taken orally every 24 hours over a period of 3 months in both groups. Two endometrial biopsies were performed. VARIABLES TO EVALUATE EFFICACY: Increase in average hemoglobin, changes in fibroid and uterine volume, and symptomatic improvement. RESULTS: The average hemoglobin at the end of treatment was 0.6 g/dL greater in the 5 mg mifepristone group (P = 0.033). In both groups there were similar reductions in fibroid volumes. Clinical improvement was more significant in the 5 mg group. CONCLUSION: The dose to be used should be 5 mg.

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Dengue virus is one of the most important arboviral pathogens and the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. It is transmitted between humans by the mosquitoes Aedes aegypti and Aedes albopictus, and at least 2.5 billion people are at daily risk of infection. During their lifecycle, mosquitoes are exposed to a variety of microbes, some of which are needed for their successful development into adulthood. However, recent studies have suggested that the adult mosquito's midgut microflora is critical in influencing the transmission of human pathogens. In this study we assessed the reciprocal interactions between the mosquito's midgut microbiota and dengue virus infection that are, to a large extent, mediated by the mosquito's innate immune system. We observed a marked decrease in susceptibility to dengue virus infection when mosquitoes harbored certain field-derived bacterial isolates in their midgut. Transcript abundance analysis of selected antimicrobial peptide genes suggested that the mosquito's microbiota elicits a basal immune activity that appears to act against dengue virus infection. Conversely, the elicitation of the mosquito immune response by dengue virus infection itself influences the microbial load of the mosquito midgut. In sum, we show that the mosquito's microbiota influences dengue virus infection of the mosquito, which in turn activates its antibacterial responses.

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In freshwater ecosystems, rotifers and cladocerans are ideal prey for fish larvae whereas copepods, due to their purported low growth rate and predatory tendency, are not. We recently isolated the parthenogenetic Elaphoidella grandidieri (Gueme et Richard, 1893) a benthic freshwater harpacticoid, from a fish farm in the State of Morelos, central Mexico and tested its potential as a live prey organism for larval vertebrates. Population growth and life table demography experiments were conducted, in 100 ml recipients with 50 ml of test medium on a diet of Scenedesmus acutus at a density of 1.0 X 10(6) cell ml(-1); the former on live algae alone while the latter on live algae as well as detritus. We also conducted experiments to document the prey preference for this copepod by the larval Ameca splendens (Pisces: Goodeidae) and Ambystoma mexicanum (Amphibia: Ambystomatidae), fed the rotifer Plationus patulus, the ostracod Heterocypris incongruens, and the cladocerans Moina macrocopa and Daphnia pulex. Elaphoidella grandidieri is relatively easy to maintain under laboratory conditions, reaching densities (copepodites and adults) of more than 10,000 l(-1). The generation time ranged between 30-45 days, depending on the diet. The net reproductive rate was as high as 60 nauplii female(-1) day (1). Population growth rates ranged between 0.03 and 0.11 d(-1), live algae being the superior diet compared to detritus. Both predators showed no preference for E. grandidieri, but in the absence of alternate prey they consumed 80% of the harpacticoids offered. The data have been discussed in relation to the potential of E. grandidierias live food for aquaculture.

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OBJECTIVES: Praziquantel and albendazole are currently used for chemotherapeutic treatment of neurocysticercosis. Albendazole has been found to be more effective than praziquantel; however, it is well known that not all patients will show a complete resolution of cysts. Searching for more effective treatments, this study was designed to evaluate the effect of the combination of praziquantel and albendazole sulphoxide in a Taenia crassiceps in vitro model as well as the kind of interaction between both drugs. METHODS: In order to determine the concentration that produced 50% effect (EC50), T. crassiceps cysts were incubated in culture medium containing praziquantel (0.005-0.04 microg/mL), albendazole sulphoxide (0.021-0.16 microg/mL) or the combination of praziquantel and albendazole sulphoxide in a fixed-dose ratio (1:1). The experimental concentration (EC50Exp) of the combination was determined from the concentration-response curve constructed from the combined drug treatment. Isobolographic analyses were used to define the nature of the interaction between praziquantel and albendazole sulphoxide. Morphological and ultrastuctural alterations after different treatments over the parasite tissue were observed by light and transmission electron microscopy. RESULTS: The changes in ultrastructure were more marked with the praziquantel and albendazole sulphoxide combination. Also the cysticidal effect of the combination was observed earlier than that of each drug alone. When isobolographic analysis was employed, we found that the experimental EC50 value (0.042 microg/mL) was not significantly different from the theoretical EC50 value (0.035 microg/mL), which indicates an additive interaction between praziquantel and albendazole sulphoxide. CONCLUSIONS: Our study suggests that the combination of praziquantel and albendazole sulphoxide could potentially improve the current neurocysticercosis treatment.

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PURPOSE: To evaluate Smoking Cessation Clinic success rate and attitudes toward smoking among current and quitters enrolled at the clinic. METHODS: Telephone survey among a random sample of 61 subjects enrolled at the Smoking Cessation Clinic in the San Juan Veterans Affairs Hospital. The questionnaire was validated and standardized for Hispanic subjects. RESULTS: Twenty eight percent of the subjects interviewed referred they had quit smoking. Quitters used to smoke more cigarettes than current smokers do. Quitters perceived their general health to be worse than current smoker's perception. Even though Quitters were concerned about weight gain after quitting, it was not a negative outcome for smoking cessation. No association was found between active smoking and use of ethanol, neither socializing with friends nor feeling anxious. CONCLUSION: The Smoking Cessation Clinic at the San Juan Veterans Affairs Hospital has a success rate similar to other clinics reported in the literature. Poor health perception and consumption of more than one pack per day predicted smoking cessation. There was no single strong factor associated to smoking cessation. The idiosyncrasy of targeted population should be taken in account when designing smoking cessation program.

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Although the sural nerve is the most extensively studied nerve in man, there is a dearth of data regarding the normal variations in the size-frequency distribution of axons in normal subjects; criteria for assessing the normality of a given individual are not available. Therefore, in everyday practice, the surgical pathologist may meet with difficulty in interpretit the biopsy of one particular individual, in whom the distribution is slightly different from the curves published. The object of this work is to detect the normal limits of variation in the distribution of diameters of muelinated and unmyelinated fibers in normal subjects and to establish the criteria that permit the calculated curves to be used in veryday clinical practice. Normal sural nerves of 19 patients were analyzed. Ages ranged between 18 months and 55 years. Morphometric analysis was performed with the Histoscan X automatic image processing analyzer, and , for statistical analysis, mixtures of lognormal distributions were fitted and tested with Pearson's statistics. Nerves of three diabetic patients were used for testing the method. They were clearly classified as abnormal. The curves, therefore, have been proven useful for everyday surgical pathology practice

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