Static and Dynamic Stabilization of the Shoulder After Total Scapulectomy in an Electric Burn Patient.

ABSTRACT: An otherwise healthy 49-year-old man experienced a high-voltage electrical injury to the left shoulder resulting in total scapulectomy, partial calviculectomy, and a substantial soft tissue defect. The majority of the muscles around his shoulder were debrided because of necrosis, with only the pectoralis and latissimus dorsi muscles remaining attached to the humerus. Surprisingly, the patient's brachial plexus remained intact, and his left elbow, wrist, and hand function were preserved. A novel combination of 3 static and dynamic suspension techniques were used to stabilize his shoulder and prevent traction injury to the brachial plexus. Postoperative follow-up at 1 year demonstrated excellent stability of his reconstructed shoulder, which allowed him to ambulate independently and return to employment.

The Role of Reconstruction on Desmoid Tumor Recurrence: A Systematic Review and Technical Considerations.

BACKGROUND: Desmoid tumors occur throughout the body, presenting as aggressive, locally invasive lesions that can impede quality of life. Many controversies remain regarding the optimal surgical treatment of desmoid. This article presents a systematic review and meta-analysis on surgical management, focusing on risk of recurrence and the utility of reconstruction within this unique patient population. METHODS: A systematic review was conducted to search for articles. The clinical course of patients diagnosed with desmoid tumors and treated by our institution's multidisciplinary team was retrospectively reviewed over a 13-year period. Meta-analysis study findings were compared with our cohort. RESULTS: From the systematic review, 10 studies with level of evidence III were found, which resulted in 981 patients. Twenty patients from our institution met the inclusion criteria for our study. In both our study cohort and the pooled results, recurrence was significantly higher in patients with positive microscopic margin after resection. In our study cohort, patients with recurrence had higher rates of positive margins compared with those without recurrence (83.3% vs 7.1%, P = 0.004), whereas the pooled study showed a difference of margin positivity of 50% vs 40% ( P = 0.01). No patients who underwent reconstruction in our study cohort had a recurrence during the study period. CONCLUSION: In both our cohort and pooled results, recurrence was significantly higher in patients with positive margins after initial resection. Reconstruction was not found to be a risk factor for recurrence. Reconstruction following desmoid tumor resection should be considered a viable option if a large and aggressive resection is required to obtain negative margins.

Comparison of 1-year healthcare resource utilization and related costs for patients with heart failure in the Chagas and non-Chagas matched cohorts.

Background: Chagas disease is one of the leading causes of heart failure (HF) in Latin Americans, and there are limited data available that examine related costs of care for patients with HF. This study aimed to compare healthcare resource utilization and related costs for patients with HF, with and without Chagas disease. Methods: A prospective matched-cohort study comparing the healthcare costs for patients with HF with Chagas disease and care costs for patients with HF without Chagas disease was conducted between January 2019 and December 2019. Only direct costs have been estimated, including hospitalization costs, medications and other cardiovascular interventions, and clinical and laboratory follow-up for up to 1 year. Results: A total of 80 patients with chronic HF were included in the study. Of the 80 patients, 40 patients in the Chagas cohort and 40 patients in the non-Chagas cohort were matched for age, insurer and sex. From a social security system perspective, the total costs for the two cohorts during the study period were U$970,136. Specifically, the healthcare costs for the Chagas cohort were greater than the total healthcare costs for the non-Chagas group (U$511,931 versus U$458,205; p = 0.6183) Most costs were associated with hospitalizations (65.5% versus 59.6%), with averages of U$12,798.5 and U$11,455.1 per person in the Chagas and non-Chagas groups, respectively. In both the Chagas (51.6%) and non-Chagas cohorts (54.5%), causes of readmission unrelated to HF outweighed causes of readmission related to HF. High incidences of hospital admissions were observed during the rainy (cold) season for both cohorts. Conclusions: Over a 12-month follow-up period, patients with chronic HF and Chagas consume as many healthcare resources as those with chronic HF and without Chagas. These data highlight the considerable and growing economic burden of HF on the Colombian health system.

Breaking Barriers to Breast Reconstruction among Socioeconomically Disadvantaged Patients at a Large Safety-net Hospital.

Socioeconomic disparities remain prevalent among those who undergo breast reconstruction. At our institution, patients must meet certain criteria to become eligible for breast reconstruction. The purpose of this study was to determine the impact of socioeconomic factors on breast reconstruction eligibility, enrollment, choice, and completion at our large safety-net institution. Methods: A retrospective chart review of patients who underwent partial or total mastectomy at a large safety-net hospital from 2016 to 2019 was completed. Surgical and demographic data were compared across varying socioeconomic factors. Results: A total of 645 patients were included in the study. More patients of a racial minority had government-based insurance than White patients (89% versus 81%; P = 0.01). Those with government-based insurance had higher average hemoglobin A1c values (6.26 versus 6.0; P = 0.03), proportion of American Society of Anesthesiologists scores greater than III (46% versus 40%; P = 0.01), and smokers (23% versus 9%; P = 0.02) than those with private insurance. Diabetic patients, patients with an American Society of Anesthesiologists greater than III, and active smokers were significantly less likely to receive a plastic surgery consult. Patients with government-based insurance underwent immediate tissue expander placement at mastectomy at rates lower than those with private insurance (57% versus 69%; P = 0.01). Conclusions: Barriers remain for socioeconomically disadvantaged patients to be eligible for, undergo, and complete breast reconstruction. Obesity, diabetes, smoking, and poor overall health were identified as the main barriers and were associated with racial minorities, government-based insurance, and lower incomes. Concerted effort through multidisciplinary teams is needed to maximize eligibility of socioeconomically disadvantaged breast cancer patients for reconstruction.

Know Thyself: Natural and Adapted Behavior Styles of General and Plastic Surgery Residents.

BACKGROUND: Resident miscommunication and fractured team dynamics are associated with decreased quality of patient care. Interventions to improve resident communication and team coordination include behavioral assessments, which promote leadership and communication skills. METHODS: In this retrospective review, general and plastic surgery residents voluntarily completed the DISC (dominance, influence, steadiness, and compliance) behavioral assessment. This validated tool is composed of four behavioral categories: dominance (D), influence (I), steadiness (S), and compliance (C). It is used to classify an individual's natural and adapted behavior styles. Results were anonymously collected and analyzed using the Pearson chi-square test. RESULTS: Of 94 surgery residents, 84 completed the survey (89 percent): 43 men and 41 women. Surgery residents combined had a significantly higher percentage of natural C's compared to the general population (23 percent versus 14 percent; p = 0.02). The majority of surgery residents adapted to C in the work environment (39 versus 36 percent; p = 0.85). There was a significant difference in male and female general surgery adapted D profiles (4 percent versus 23 percent; p = 0.05). CONCLUSIONS: The pressure of accuracy in surgical residency attracts natural C individuals. Residents without a natural C behavioral profile tend to adapt to the C profile. The ability to recognize behavior traits is crucial in surgical residency. Developing a better understanding of one's own behavior will provide insight into personal risk factors for miscommunication and inefficient team dynamics.

Tissue Expander-Based Breast Reconstruction at a Major Safety-Net Hospital: Managing the Outsized Risk of Infection.

Background: Immediate tissue expander (TE) breast reconstruction is reported to have the highest rate of postoperative infection among reconstructive modalities. The risk of infection is higher among patients treated at safety-net hospitals. Objectives: The goal of this study was to identify significant contributing factors to the elevated infection risk at our major safety-net institution. Methods: A retrospective chart review was conducted on all TE-based reconstruction patients with a diagnosis of postoperative infection between 2015 and 2019. Preoperative, perioperative, and postoperative risk factors for infection were determined and compared across patient and procedure demographics. Results: Two hundred forty-three patients, for a total of 412 breast reconstructions, were included in our study. Significant preoperative selection factors were identified to contribute to the elevated risk of infection, including the following: older age, higher BMI, and diabetes. Significant intraoperative and postoperative contributing factors included greater mastectomy weight, larger TE's and intraoperative fill volume, and longer drain duration. Doxycycline treatment for infected patients resulted in a significantly higher rate of resolution. Conclusions: Safety-net hospital population patients undergoing TE breast reconstruction are at higher risk for postoperative infection. Personal and procedural risk factors are identified. Balancing the benefits of immediate breast reconstruction with TEs with the elevated risk of postoperative infection remains challenging. Implementation of more stringent eligibility criteria may help mitigate the risk of infection.

Global Pandemic and Plastic Surgery Residency Match: Can Social Media Fill the Void?

BACKGROUND: The type of content that influences plastic and reconstructive surgery (PRS) residency program selection and attracts applicants is continually changing and not clearly understood. Further, the COVID-19 pandemic has had a major yet undetermined impact on residency selection. OBJECTIVES: The purpose of this study was to determine the type of PRS social media (SM) content that drives prospective applicants' interest in a residency program, and the degree of SM influence on applicants, especially in the context of COVID-19. METHODS: Prospective PRS residency applicants were surveyed anonymously. RESULTS: An average of 60% of respondents reported that PRS SM content influenced their perception of a program. Fifty-eight percent reported that resident lifestyle content made them more interested in a program. Separately, 32% reported that resident lifestyle content influenced them to rank a program higher. Seventy-two percent of respondents claimed SM content did not make them lose interest in a program. Rarely posting, outdated content, and lack of engagement were cited as factors for loss of interest in a program. A majority of respondents (53%) reported wanting to see more resident life and culture content on SM. Of the existing PRS SM content, respondents were most interested in resident lifestyle, followed by clinical and program-specific content. CONCLUSIONS: The COVID-19 pandemic amplified the importance of SM PRS residency selection. Resident lifestyle content was consistently indicated as more likely to make respondents gain interest in a program, rank a program higher, and as the most desired content. PRS programs will benefit from highlighting resident camaraderie, quality of life, hobbies, and lifestyle to attract applicants.

Post-operative delirium in older hip fracture patients: a new onset or was it already there?

PURPOSE: Hip fractures are a worldwide health issue primarily for older patients, conditioning major morbidity and mortality. An experienced multidisciplinary team is essential to manage surgery and peri-operative implications, to enable rapid functional and cognitive recovery. Delirium is a recognizable problem associated with negative outcomes. Our study aims to determine the influence of pre-operative delirium in the incidence of post-operative delirium, and to evaluate the association between other known peri-operative risk factors with both conditions. METHODS: A single-center, retrospective cohort study, conducted at a Level II trauma center over a 14-month period, included 241 patients with 65 years of age or older submitted to hip fracture surgery. Peri-operative data were gathered regarding baseline characteristics (sociodemographic, functional and cognitive status), intra-operative events (anesthesia technique, surgery duration, blood loss) and post-operative outcomes (delirium occurrence). RESULTS: Statistical analysis evidenced a female (75.5%) and elderly population (83.9 ± 7.8 years old) with significant comorbidities (cognitive impairment in 51.9%, ASA ≥ III in 79.7%, mean CIRS-G 8.83 ± 4.69) that underwent surgical fracture repair, mostly under 4 h (96.3%) and under regional anesthesia (63.1%). Pre- and post-operative delirium incidence was 18.3% and 12.9%, respectively, displaying increased presence according to cognitive impairment severity. CONCLUSION: Post-operative delirium was almost inexistent when it was absent pre-operatively. Moreover, pre-operative cognitive status was associated with the development of pre- and post-operative delirium. Careful cognitive assessment, implementation of preventive strategies and avoidance of peri-operative pro-delirium factors are crucial for comprehensive geriatric care.

Geriatric care in European countries where geriatric medicine is still emerging.

PURPOSE: Practicing geriatric medicine is a challenging task since it involves working together with other medical doctors while coordinating a multidisciplinary team. Global Europe Initiative (GEI) group within the European Geriatric Medicine Society gathers geriatricians from different regions where geriatrics is underrepresented or still developing to promote initiatives for the advancement of geriatric medicine within these countries. METHODS: Here we present a first effort to describe several aspects that affect practicing geriatric medicine in five different countries: Greece, Portugal, Russia, Turkey, and Tunisia. RESULTS: We can notice discrepancies between countries concerning all dimensions of geriatrics (recognition, training, educational and professional standards, academic representation, working context). CONCLUSIONS: These differences correspond to the specificities of each country and set the frame where geriatric medicine is going to be developed across Europe. EuGMS with GEI group can provide useful support.

The UriCath study: characterization of the use of indwelling urinary catheters among hospitalized older patients in the Internal Medicine Departments of Portugal.

PURPOSE: Approximately 25% of older inpatients have an indwelling urinary catheter (IUC), 45-54% unnecessarily. This study aims to describe the prevalence, indications, and complications of IUC use in Portuguese older inpatients. METHODS: Multicentric, cross-sectional, observational study conducted in Portuguese internal medicine wards (UriCath). RESULTS: Of a total of 3135 inpatients from 39 hospitals, we included 628 patients with 65 years old or more using an IUC, mean age 82.0 ± 7.5. Prevalence of IUC use was 20.0%. The average Barthel Index was 44.0 ± 37.3 and Charlson comorbidity Index was 7.0 ± 2.8. The main reasons for IUC use were: urinary output monitoring (47.5%), urinary retention (22.5%), and pressure ulcers (11.0%). The IUC removal was attempted in 9.1% and 24.7% developed a complication. CONCLUSION: IUC use among older inpatients is prevalent and often inappropriate. Clinical awareness and development guidelines for restricted use of IUC are essential to reduce morbimortality and healthcare costs.

Metallosis: A New Form of Autoimmune/Autoinflammatory Syndrome Induced by Adjuvants Syndrome (ASIA)?

Autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA) is a new entity in which exposure to an adjuvant triggers an aberrant autoimmune response. Metallosis is a rare condition characterized by the deposition and build-up of metal debris in the soft tissues of the body associated with metal-on-metal (MOM) prosthetic devices. It can present with local/systemic symptoms and signs due to a chronic inflammatory host response. The authors present the case of a 51-year-old woman with a 6-month history of systemic complaints due to intoxication with metal ions from hip metallosis. This case highlights the importance of follow-up and continuous monitoring of patients with a hip prosthesis. As this is a rare condition, a patient presenting with unspecific symptoms such as ASIA syndrome induced by metallosis requires a high level of clinical suspicion as the removal of the adjuvant can resolve the condition. LEARNING POINTS: Asia syndrome is a new entity in which exposure to an adjuvant triggers an aberrant autoimmune response.Metallosis is an uncommon condition with local and systemic presentation.A high level of suspicion and close monitoring is needed in patients with vague systemic complaints.

European postgraduate curriculum in geriatric medicine developed using an international modified Delphi technique.

BACKGROUND: the European Union of Medical Specialists (UEMS-GMS) recommendations for training in Geriatric Medicine were published in 1993. The practice of Geriatric Medicine has developed considerably since then and it has therefore become necessary to update these recommendations. METHODS: under the auspices of the UEMS-GMS, the European Geriatric Medicine Society (EuGMS) and the European Academy of Medicine of Ageing (EAMA), a group of experts, representing all member states of the respective bodies developed a new framework for education and training of specialists in Geriatric Medicine using a modified Delphi technique. Thirty-two expert panel members from 30 different countries participated in the process comprising three Delphi rounds for consensus. The process was led by five facilitators. RESULTS: the final recommendations include four different domains: 'General Considerations' on the structure and aim of the syllabus as well as quality indicators for training (6 sub-items), 'Knowledge in patient care' (36 sub-items), 'Additional Skills and Attitude required for a Geriatrician' (9 sub-items) and a domain on 'Assessment of postgraduate education: which items are important for the transnational comparison process' (1 item). CONCLUSION: the current publication describes the development of the new recommendations endorsed by UEMS-GMS, EuGMS and EAMA as minimum training requirements to become a geriatrician at specialist level in EU member states.

Elimination of onchocerciasis from Colombia: first proof of concept of river blindness elimination in the world.

BACKGROUND: Onchocerciasis is a chronic parasitic infection originally endemic in 13 discrete regional foci distributed among six countries of Latin America (Brazil, Colombia, Ecuador, Guatemala, Mexico and Venezuela). In Colombia, this disease was discovered in 1965 in the Pacific Coast of the country. The National Onchocerciasis Elimination Program was established in 1993 with the aim of eliminating disease morbidity and infection transmission. In 2013, the World Health Organization (WHO) verified Colombia as free of onchocerciasis, becoming the first country in the world to reach such a goal. This report provides the empirical evidence of the elimination of Onchocerca volvulus transmission by Simulium exiguum (s.l.) after 12 years of 6-monthly mass drug administration of Mectizan® (ivermectin) to all the eligible residents living in this endemic area. METHODS: From 1996 onwards, a biannual community-based mass ivermectin administration programme was implemented, complemented by health education and community participation. In-depth parasitological, serological and entomological surveys were conducted periodically between 1998 and 2007 to evaluate the impact of ivermectin treatment according to the 2001 WHO guidelines. When the interruption of parasite transmission was demonstrated, the drug distribution ceased and a three-year post-treatment surveillance (PTS) period (2008-2010) was initiated. RESULTS: After 23 rounds of treatment, parasitological and ophthalmological assessments showed absence of microfilariae in skin and anterior chamber of the eyes. Serological tests proved lack of antibodies against O. volvulus in children under 10 years-old. A total of 10,500 S. exiguum flies tested by PCR had no L3 infection (infectivity rate = 0.0095%; 95% CI: 0.0029-0.049) during 2004, indicating interruption of parasite transmission. However, biannual ivermectin treatments continued until 2007 followed by a 3-year PTS period at the end of which 13,481 flies were analyzed and no infective flies were found (infectivity rate = 0%; 95% CI: 0.0-0.014). CONCLUSIONS: These results fulfilled the WHO criteria for onchocerciasis elimination. Consequently, in 2013 Colombia was verified as free of onchocerciasis, demonstrating that elimination of this neglected tropical disease is an achievable goal and paving the way for an elimination agenda to be followed by other endemic countries in Latin America and Africa.

Prevalence and treatment outcomes of routine Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis testing during antenatal care, Gaborone, Botswana.

OBJECTIVES: Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) are curable, mostly asymptomatic, STIs that cause adverse maternal and perinatal outcomes. Most countries do not test for those infections during antenatal care. We implemented a CT, NG and TV testing and treatment programme in an antenatal clinic in Gaborone, Botswana. METHODS: We conducted a prospective study in the antenatal clinic at Princess Marina Hospital in Gaborone, Botswana. We offered pregnant women who were 18 years or older and less than 35 weeks of gestation, CT, NG and TV testing using self-collected vaginal swabs. Testing was conducted using a GeneXpert® CT/NG and TV system. Those who tested positive were given directly observed antibiotic therapy and asked to return for a test of cure. We determined the prevalence of infections, uptake of treatment and proportion cured. The relationships between positive STI test and participant characteristics were assessed. RESULTS: We enrolled 400 pregnant women. Fifty-four (13.5%) tested positive for CT, NG and/or TV: 31 (8%) for CT, 5 (1.3%) for NG and 21 (5%) for TV. Among those who tested positive, 74% (40) received same-day, in person results and treatment. Among those who received delayed results (6), 67% (4) were treated. Statistical comparisons showed that being unmarried and HIV infected were positively association CT, NG and/or TV infection. Self-reported STI symptoms were not associated with CT, NG and/or TV infection. CONCLUSION: The prevalence of CT, NG and/or TV was high, particularly among women with HIV infection. Among women with CT, NG and/or TV infection, those who received same-day results were more likely to be treated than those who received delayed results. More research is needed on the costs and benefits of integrating highly sensitive and specific STI testing into antenatal care in Southern Africa.

Risk factors for treatment interruption and severe adverse effects to benznidazole in adult patients with Chagas disease.

BACKGROUND: Etiological treatment of Chagas disease in chronic asymptomatic patients is still in debate and the adverse effects of traditional drugs are one of the main concerns in clinical practice. This study evaluated retrospectively the safety profile of benznidazole (BZN) and identified predictive factors for definite treatment interruption and development of severe reactions in adult patients treated with BZN in Colombia. METHODS: Retrospective follow-up study conducted by review of medical records of adults with chronic Chagas disease treated with BZN in Colombia. A parametric survival analysis based on a generalized gamma distribution was used for assessing risk factors for treatment interruption. A multinomial logistic regression model was used to estimate the probability of severe adverse drug reactions (ADRs). Statistical associations were expressed as time ratios (TR) and adjusted odds ratios (aOR) respectively. RESULTS: In total 224 adults patients treated with BZN were included; 172 (76.8%) completed the standard therapy (60 days of treatment), 205 (91.5%) presented ADRs and 52 cases (23.2%) required treatment interruption. The predominant symptoms were: rash (37.9%), itching (33.7%), epigastric pain (26.4%), abdominal bloating (24.2%) and nausea (22.1%). ADRs were mild (57.4%), moderate (35.5%) and severe (7.3%). Time to treatment interruption was significantly shorter when using doses of BZN ≥ 6 mg/kg/day (TR 0.55; 95% CI 0.39-0.76), presenting severe ADRs (TR 0.12; 95% CI: 0.07-0.19) and eosinophilia (TR 0.68; 95% CI: 0.49-0.94). Female sex (aOR 3.98; 95% CI 1.56-10.16), dose of BZN ≥ 6 mg/kg/day (aOR 1.41; 95% CI 1.17-1.70) and presence of > 3 ADRs (aOR 6.47; 95% CI 1.24-34.34) were considered as risk factors for developing severe ADRs. CONCLUSIONS: Dose, severity of ADRs, eosinophilia and female sex were the main predictors for treatment interruption or severe ADRs. The potential implications of these findings are discussed.

[Gene polymorphisms in the dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) genes and structural modelling of the dhps gene in Colombian isolates of Toxoplasma gondii]. / Polimorfismos en los genes de dihidrofolato-reductasa ( dhfr ) y dihidropteroato-sintasa ( dhps ) y modelado estructural del gen dhps en aislamientos colombianos de Toxoplasma gondii.

INTRODUCTION: There are no reports describing polymorphisms in target genes of anti- Toxoplasma drugs in South American isolates. OBJECTIVE: This study sought to perform cloning and sequencing of the dihydrofolate reductase ( dhfr ) and dihydropteroate-synthase ( dhps ) genes of the reference Rh strain and two Colombian isolates of Toxoplasma gondii . MATERIALS AND METHODS: Two isolates were obtained from the cerebrospinal fluid of HIV-infected patients with cerebral toxoplasmosis. A DNA extraction technique and PCR assay for the dhfr and dhps genes were standardized, and the products of amplification were cloned into Escherichia coli and sequenced. RESULTS: One polymorphism (A « G) was found at position 235 of exon 2 in the dhps gene. In addition, two polymorphisms (G « C) at positions 259 and 260 and one polymorphism (T « G) at position 371 within exon 4 of the dhps gene were detected. In this last exon, a bioinformatic analysis revealed a non-synonymous polymorphism in the coding region that could lead to the substitution of Glu (CAA or CAG) for His (encoded by codons AAU or AAC). A structural model of the T. gondii DHPS protein was calculated, and the results revealed modifications in secondary structure due to mutations. CONCLUSIONS: The methods described in this study can be used as a tool to search for polymorphisms in samples from patients with different clinical manifestations of toxoplasmosis and to examine their relationship with the therapeutic response.

Polimorfismos en los genes de dihidrofolato-reductasa ( dhfr ) y dihidropteroato-sintasa ( dhps ) y modelado estructural del gen dhps en aislamientos colombianos de Toxoplasma gondii / Gene polymorphisms in the dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) genes and structural modelling of the dhps gene in Colombian isolates of Toxoplasma gondii

Introducción. No existen reportes sobre las variaciones en la secuencia de los genes blanco de los medicamentos anti- Toxoplasma en aislamientos provenientes de Suramérica. Objetivo. Clonar y secuenciar los genes de la dihidrofolato-reductasa ( dhfr ) y la dihidropteroato-sintetasa ( dhps ) de la cepa de referencia RH y de dos aislamientos colombianos de Toxoplasma gondii. Materiales y métodos. Se obtuvieron dos aislamientos de T. gondii en líquido céfalorraquídeo de pacientes colombianos positivos para HIV con toxoplasmosis cerebral. Se extrajo el ADN de los genes dhfr y dhps y se amplificaron mediante reacción en cadena de la polimerasa (PCR). Los productos fueron clonados en el vector pGEM-T y secuenciados. Resultados. Se encontró un cambio de adenina por guanina (A « G) en la posición 235 del exón 2 del gen dhps , dos cambios de guanina por citocina (G « C) en las posiciones 259 y 260 y un cambio de timina por guanina (T « G) en la posición 371 del exón 4 del gen dhps. Por análisis bioinformático, en este último exón se identificó un polimorfismo no sinónimo en la región codificante, que podría llevar al cambio de una Glu (CAA o CAG) por una His (codificada por los codones AAU o AAC). Se calculó el modelo estructural de la enzima dihidropteroato-sintetasa (DHPS) de T. gondii y se identificaron las modificaciones en la estructura secundaria ocasionadas por las mutaciones. Conclusiones. La metodología estandarizada puede servir como base para la búsqueda de polimorfismos en muestras de pacientes con diferentes manifestaciones clínicas de toxoplasmosis y para establecer su posible relación con los cambios en la sensibilidad a los antifolatos y la reacción al tratamiento.

Introduction: There are no reports describing polymorphisms in target genes of anti- Toxoplasma drugs in South American isolates. Objective: This study sought to perform cloning and sequencing of the dihydrofolate reductase ( dhfr ) and dihydropteroate-synthase ( dhps ) genes of the reference Rh strain and two Colombian isolates of Toxoplasma gondii . Materials and methods: Two isolates were obtained from the cerebrospinal fluid of HIV-infected patients with cerebral toxoplasmosis. A DNA extraction technique and PCR assay for the dhfr and dhps genes were standardized, and the products of amplification were cloned into Escherichia coli and sequenced. Results: One polymorphism (A « G) was found at position 235 of exon 2 in the dhps gene. In addition, two polymorphisms (G « C) at positions 259 and 260 and one polymorphism (T « G) at position 371 within exon 4 of the dhps gene were detected. In this last exon, a bioinformatic analysis revealed a non-synonymous polymorphism in the coding region that could lead to the substitution of Glu (CAA or CAG) for His (encoded by codons AAU or AAC). A structural model of the T. gondii DHPS protein was calculated, and the results revealed modifications in secondary structure due to mutations. Conclusions: The methods described in this study can be used as a tool to search for polymorphisms in samples from patients with different clinical manifestations of toxoplasmosis and to examine their relationship with the therapeutic response.