Absence of knockdown mutations in pyrethroid and DDT resistant populations of the main malaria vectors in Colombia.

BACKGROUND: Knockdown resistance (kdr) is a well-characterized target-site insecticide resistance mechanism that is associated with DDT and pyrethroid resistance. Even though insecticide resistance to pyrethroids and DDT have been reported in Anopheles albimanus, Anopheles benarrochi sensu lato (s.l.), Anopheles darlingi, Anopheles nuneztovari s.l., and Anopheles pseudopunctipennis s.l. malaria vectors in Latin America, there is a knowledge gap on the role that kdr resistance mechanisms play in this resistance. The aim of this study was to establish the role that kdr mechanisms play in pyrethroid and DDT resistance in the main malaria vectors in Colombia, in addition to previously reported metabolic resistance mechanisms, such as mixed function oxidases (MFO) and nonspecific esterases (NSE) enzyme families. METHODS: Surviving (n = 62) and dead (n = 67) An. nuneztovari s.l., An. darlingi and An. albimanus mosquitoes exposed to diagnostic concentrations of DDT and pyrethroid insecticides were used to amplify and sequence a ~ 225 bp fragment of the voltage-gated sodium channels (VGSC) gene. This fragment spanning codons 1010, 1013 and 1014 at the S6 segment of domain II to identify point mutations, which have been associated with insecticide resistance in different species of Anopheles malaria vectors. RESULTS: No kdr mutations were detected in the coding sequence of this fragment in 129 samples, 62 surviving mosquitoes and 67 dead mosquitoes, of An. darlingi, An. nuneztovari s.l. and An. albimanus. CONCLUSION: Mutations in the VGSC gene, most frequently reported in other species of the genus Anopheles resistant to pyrethroid and DDT, are not associated with the low-intensity resistance detected to these insecticides in some populations of the main malaria vectors in Colombia. These results suggest that metabolic resistance mechanisms previously reported in these populations might be responsible for the resistance observed.

Prevalence of obesity and its association with blood pressure, serum lipids and selected lifestyles in a Puerto Rican population of adolescents 12-16 years of age

OBJECTIVES: To describe the prevalence of obesity and determine its association with blood pressure, serum lipids and lifestyles in adolescents attending a public junior-high school in San Juan, Puerto Rico. METHODS: During the 1999-2000 academic school year, 352 students, ranging in age from 12 years to 16 years, were screened for weight, height, and blood pressure. A sub-sample of voluntary adolescents (n = 26) was screened for serum lipids and lifestyles were assessed using a standardized questionnaire. RESULTS: The prevalence of level I obesity and level II obesity among 12 to 16 years old adolescents were 33.2 per cent and 2 per cent, respectively. The mean systolic and diastolic blood pressures were significantly higher in obese than in non-obese adolescents (p < .001). There were no significant differences in serum lipids between the study groups (p > .05). However, the obese group showed higher median levels of total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglycerides. The study group reported engaging in hazardous lifestyles (alcohol intake, smoking, and unhealthy eating patterns), but no real differences in lifestyles were found between obese and non-obese groups (p > .05). CONCLUSIONS: A high prevalence of level I and level II obesity was found in this population. In addition, significant positive correlations between blood pressure and body mass index were observed. This study underscores the need to assess the burden of obesity in Puerto Rico in order to develop community intervention strategies encouraging early detection and conduct modification towards healthier lifestyles.

Inmunofenotipificación de linfocitos en sangre periférica de pacientes chagásicos crónicos chilenos mediante citometría de flujo / Immnunophenotyping by flow cytometry of peripheral blood lymphocytes from Chilean chronic chagasic patients

Background: Cellular immune mechanisms of the resistance to infection by T cruzi as well as the pathogenesis of Chagas disease are still controversial. Aim: To quantify and analyse the peripheral blood immune cells from chagasic and non chagasic patients by flow cytometry. Patients and methods: Peripheral blood samples were taken from 21 individuals seropositive for Chagas disease, under no specific treatment. Control samples from 21 healthy blood donors were also obtained. To quantify immune cells populations by flow cytometry, antibodies against CD3, CD4, CD8, CD16/56, CD45/14, CD19 and HLA-DR markers were used. Results: The percentage of CD8+ cells was low and the CD4+/CD8+ ratio was high in chagasic patients, compared to their non infected counterparts. No statistically significant differences in the number of CD4+, NK, B, CD4+HLADR+ and CD8+HLADR+ cells, were observed within the two groups. Conclusions: These results show that Chilean chronic chagasic patients have lower percentage of CD8+ cells and higher CD4+/CD8+ ratio than non infected individuals

[Lipid profile in newborns with intrauterine growth retardation]. / Perfil lipídico en recién nacidos con retardo del crecimiento intrauterino.

BACKGROUND: The X syndrome, related to coronary disease in adults, could be possibly programmed priory to delivery, in children with intrauterine growth retardation. AIM: To measure serum lipids in newborns with symmetrical or asymmetrical intrauterine growth retardation. PATIENTS AND METHODS: One hundred thirty-five newborns with intrauterine growth retardation and 116 normal term newborns, with 38 to 41 gestational weeks, were studied. Total, HDL, and LDL cholesterol, triglycerides and apoproteins. A1 and B were measured in umbilical cord blood samples. RESULTS: No differences in total, HDL, LDL cholesterol, apoproteins A1 and B were observed between the study groups. Triglycerides were higher in newborns with intrauterine growth retardation, compared to normal term newborns (45 +/- 27 and 36 +/- 19 mg/dl respectively, p < 0.001). Differences in serum triglyceride levels respect to controls were observed in both male and female newborns with asymmetrical growth retardation. Likewise the differences respect to controls were observed in newborns with mild or severe but not with moderate growth retardation. CONCLUSIONS: Newborns with intrauterine growth retardation have higher triglyceride levels than normal term newborns.

Evaluación serológica del tratamiento de la enfermedad de Chagas crónica con alopurinol e itraconazol / Serologic evaluation of treatment of chronic Chagas disease with allopurinol and itraconazole

Background: Chagas disease is endemic in Chile. Allopurinol and itraconazole have activity against Trypanosoma cruzi and are recommended for the treatment of chronic disease in adults. Aim: To evaluate the chemotherapeutic effects of allopurinol and itraconazole using conventional and non conventional serologic test. Patients and methods: Sera of 90 patients with chonic Chagas disease were studied before and after 9 to 11 months of treatment with allopurinol or itraconazole and after two month of treatment with placebo. Indirect immunofluorescence, ELISA and Western Blot analysis were the conventional serologic tests used and antibody dependent complement mediated lysis (CoML) the non conventional test. Results: There were no differences in ELISA and indirect immunofluorescence tests before and after therapy. Antigenic recognition profiles by Western Blot showed qualitative and quantitative differences in a small number of cases. CoML showed that the greater negativity was achieved in the Chagasic group treated with allopurinol or itraconazole that had a negative xenodiagnosis before drugs treatment (35.8 and 61.6 percent, respectively). Conclusions: There is a reversion of lytic activity in sera of patients with negative xenodiagnosis before treatment, suggesting the parasitemia could be an important parameter to be considered in the chemotherapy of Chagas disease

[Serum lipid levels in children and teenagers from Concepción, Chile]. / Perfil lipídico y prevalencia de dislipidemias en niños y adolescentes de Concepción, Chile.

BACKGROUND: There is a relationship between serum lipid levels in children with those of adults. Preventive measures to reduce serum lipid levels should start in childhood. AIM: To study serum lipid levels in a representative sample of children and teenagers from Concepción, Chile. SUBJECTS AND METHODS: Serum total, HDL cholesterol and triglycerides were measured in 1,286 males and 816 females from 5 to 18 years old in the city of Concepción. RESULTS: Mean total cholesterol levels were 159 +/- 30 and 162 +/- 31 mg/dl in males and females respectively. The figures for HDL cholesterol were 46 +/- 11 and 47 +/- 11 mg/dl, for LDL cholesterol were 94 +/- 27 and 96 +/- 29 mg/dl and for triglycerides were 80 +/- 35 and 87 +/- 38 mg/dl. Nine percent of males and 12% of females had a total cholesterol over 200 mg/dl. Likewise 10% of males and 11% of females had a LDL cholesterol over 130 mg/dl. CONCLUSIONS: These numbers will help to plan and perform interventions in children, in order to prevent cardiovascular diseases.

Embolia calcificada a la arteria coronaria por degeneración de bioprótesis en posición aórtica / Calcified embolism of the coronary artery by degeneration of bioprothesis in aortic position

Se presenta un caso de embolia arterial coronaria por material calcificado de una bioprótesis de pericardio bovino del INC en posición aórtica 8 años después de su implantación. Se realizaron estudios de ecordiograma y cateterismo con coronariografía, que demostraron disfunción protésica aórtica y coronarias normales. Antes de internarse al hospital, el paciente refería angor y disnea. Durante la coronariografía hubo un aumento de la sintomatología, acompañado de cambios electrocardiográficos y horas después con elevación enzimática. El paciente fue llevado de urgencia a cirugía donde se efectuó un recambio protésico mitroaórtico con prótesis mecánica. Como hallazgos quirúrgicos: ausencia de una valva de la prótesis en posición aórtica, con calcio libre fragmentado en la región perianular y las dos valvas restantes completamente calcificadas, la prótesis en posición mitral de apariencia normal. Concluimos que la isquemia o el infarto de miocardio en presencia de coronarias normales en pacientes con bioprótesis de pericardio bovino en posición aórtica puede ser secundaria a embolia por calcio, originada por el proceso de mineralización de una bioprótesis degenerada años después de su implantación