MTHFR c.677C>T is a risk factor for non-syndromic cleft lip with or without cleft palate in Chile.

OBJECTIVE: The functional variant within the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene c.677C>T, producing alterations in folate metabolism, has been associated with the risk of non-syndromic cleft lip with or without cleft palate (NSCL/P). We assessed this association in a Chilean population using a combined analysis of case-control and case-parent trio samples. SUBJECTS AND METHODS: Samples of 165 cases and 291 controls and 121 case-parent trios (sharing the cases) were genotyped. Odds ratio (OR) was estimated for case-control (allele and genotype frequency differences), and this result was confirmed by allele transmission distortion in trios. Due to that these samples are not independent, a combined OR was also computed. Maternal genotype effect was additionally evaluated based on a log-linear method. RESULTS: Borderline but not significant OR (1.28; CI 0.97-1.69) was observed for risk allele (T) in the case-control sample. However, triad sample showed a significant association (OR 1.56: CI 1.09-2.25) which was confirmed by the combined OR (1.37; CI 1.11-1.71). Maternal genotype has been also associated with the phenotype (P = 0.002). CONCLUSIONS: In contrast to previous reports considering Chilean subjects, our results demonstrated that the offspring and maternal genotypes for MTHFR c.677C>T variant are strongly associated with NSCL/P in this Chilean population.

Genetic risk score for nonsyndromic cleft lip with or without cleft palate for a Chilean population.

It has been widely accepted that nonsyndromic cleft lip with or without cleft palate (NSCLP) depends on the altered function of several genes during craniofacial development. The construction of genetic risk score (GRS) have allowed to estimate the combined effect of risk alleles from genes interacting in different molecular pathways in order to improve an estimation of the individual's susceptibility to a complex disease. The aim of our study was to construct a GRS considering markers showing previous allele/haplotype association with NSCLP in Chile. Considering 10 risk markers from IRF6, MSX1, BMP4 and TGFB3 genes, we estimate a GRS for each of 152 NSCLP cases and 164 controls. GRS showed no significant results when comparing cases and controls for these markers. These results could be explained by a possible indirect relationship of these genes between them in NSCLP which GRS is not capable of detecting and/or the modest number of risk alleles considered herein.

The Chilean socio-ethno-genomic cline.

Studies of the current Chilean population performed using classical genetic markers have established that the Chilean population originated primarily from the admixture of European people, particularly Spaniards, and Amerindians. A socioeconomic-ethno-genetic cline was established soon after the conquest. Spaniards born in Spain or Chile occupied the highest Socioeconomic Strata, while Amerindians belonged to the lowest. The intermediate strata consisted of people with different degrees of ethnic admixture; the larger the European admixture, the higher the Socioeconomic Level. The present study of molecular genomic markers sought to calculate the percentage of Amerindian admixture and revealed a finer distribution of this cline, as well as differences between two Amerindian groups: Aymara and Mapuche. The use of two socioeconomic classifications - Class and Socioeconomic Level - reveals important differences. Furthermore, Self-reported Ethnicity (self-assignment to an ethnic group) and Self-reported Ancestry (self-recognition of Amerindian ancestors) show variations and differing relationships between socioeconomic classifications and genomic Amerindian Admixture. These data constitute a valuable input for the formulation of public healthcare policy and show that the notions of Ethnicity, Socioeconomic Strata and Class should always be a consideration in policy development.

Association analysis in a Latin American population revealed ethnic differences in rheumatoid arthritis-associated SNPs in Caucasian and Asian populations.

Large genome-wide association studies (GWAS) have increased our knowledge of the genetic risk factors of rheumatoid arthritis (RA). However, little is known about genetic susceptibility in populations with a large admixture of Amerindian ancestry. The aim of the present study was to test the generalizability of previously reported RA loci in a Latin American (LA) population with admixed ancestry. We selected 128 single nucleotide polymorphisms (SNPs) in linkage equilibrium, with high association to RA in multiple populations of non-Amerindian origin. Genotyping of 118 SNPs was performed in 313 RA patients/487 healthy control subjects by mid-density arrays of polymerase chain reaction (PCR). Some of the identified associations were validated in an additional cohort (250 cases/290 controls). One marker, the SNP rs2451258, located upstream of T Cell Activation RhoGTPase Activating Protein (TAGAP) gene, showed significant association with RA (p = 5 × 10-3), whereas 18 markers exhibited suggestive associations (p < 0.05). Haplotype testing showed association of some groups of adjacent SNPs around the signal transducer and activator of transcription 4 (STAT4) gene (p = 9.82 × 10-3 to 2.04 × 10-3) with RA. Our major finding was little replication of previously reported genetic associations with RA. These results suggest that performing GWAS and admixture mapping in LA populations has the potential to reveal novel loci associated with RA. This in turn might help to gain insight into the 'pathogenomics' of this disease and to explore trans-population differences for RA in general.

[Family risk perception to diabetes mellitus]. / Percepción de riesgo familiar a desarrollar diabetes mellitus.

OBJECTIVE: To describe the relation between risk perception of people with relatives who have been hospitalized with diabetes mellitus, and also their modifiable risk factors. MATERIAL AND METHOD: We applied a validated questionnaire to a hundred of people who have any relatives with diabetes mellitus, because we wanted to know their perception for risk of this disease and their modifiable risk factors, as obesity, sedentary life style and meals. We think that the relatives who have two or more modifiable risk factors have a higher probability to develop diabetes mellitus than the relatives who have only one of them. RESULTS: The risk perception to develop diabetes in patients' relatives could be 87%; 67% has fat, and 73% has a sedentary life style. So, the relation among the modification of risk factors and the risk perception towards diabetes mellitus was not really significant (p = 0.399, RR 0.94, IC 0.80-1.10 to 95%), but there is a statistical relation among high risk for diabetes mellitus acquisition and gender (chi2 5.0, p < 0.05, RR 1.61, IC 1.00 < Rr -2.58), when we associate the variable age and obesity (chi2 7.9, p < 0.05, RR 0.59, IC 0.37-0.93). CONCLUSIONS: More of 50 % patients' relatives are in a high risk to develop diabetes mellitus because they have a similar life style than the patient had before getting the illness. For this reason, we suggest a different educational and cultural orientation in Mexico to identify all people in risk and do following of previous parameters about their health.

Maternal biomarkers of methylation status and non-syndromic orofacial cleft risk: a meta-analysis.

Animal models have shown evidence of the role of maternal methyl donor status and its metabolism (one-carbon metabolism) in normal embryonic maxillofacial development. Nevertheless, studies in humans have shown conflicting results for the association of maternal methylation status biomarkers in the aetiology of the main craniofacial birth defects: non-syndromic orofacial clefts (NSOFCs). The aim of this study was to perform a meta-analysis assessing the relationship between maternal levels of methylation status biomarkers (plasma and erythrocyte folates and plasma vitamin B12 and homocysteine) and the risk of NSOFCs. A literature search of the conventional and grey medical-scientific databases identified 12 studies considering these variables. Based on standardized differences between means among cases and controls (Cohen's d test), evidence was found of an association only with high plasma homocysteine (d=0.37; P=0.026) when single effects were pooled. In addition to its usefulness as a marker of poor methyl-donor intake and/or metabolism, homocysteine appears to have a teratogenic effect. Although the results are based on a relatively small number of reports and/or studies of small sample sizes showing between-study heterogeneity, these problems were resolved by including an additional analysis. Therefore these findings constitute a real contribution towards explaining the complex aetiology of orofacial clefts.

Maternal obesity is a risk factor for orofacial clefts: a meta-analysis.

Orofacial clefts are the most prevalent birth defects that affect craniofacial structures and implicate genetic and environmental factors in their aetiology. Maternal metabolic state and nutrition have been related to these and other structural malformations, and studies of maternal obesity before pregnancy have shown controversial results about its association with the risk of orofacial clefts in their offspring. Our aim was to assess the combined effect of several single studies of maternal obesity on the risk of orofacial clefts using meta-analysis. We searched for these reports in the PubMed database, and selected 8 studies that met our criteria for eligibility. As a result of this analysis, and using maternal normal weight as a reference, we found that maternal obesity does increase the risk of orofacial clefts in their offspring (OR 1.18, 95% CI 1.11 to 1.26). When these clefts are considered separately, maternal obesity is associated with cleft lip with or without cleft palate (OR 1.13, 95% CI 1.04 to 1.23), and with cleft palate alone (OR 1.22, 95% CI 1.09 to 1.35). Our results support the relation between maternal obesity and orofacial clefts, and confirm two previous meta-analyses that considered fewer studies. However, the molecular mechanisms underlying this statistical evidence have not been fully elucidated.

Fluoxetine impairs insulin secretion without modifying extracellular serotonin levels in MIN6 ß-cells.

INTRODUCTION: Pancreatic ß-cells synthetize and store Serotonin (5-Hydroxytriptamine, 5HT) which is co-released with insulin. It has been proposed that extracellular 5HT binds to specific cell surface receptors and modulate insulin secretion. On the other hand, Selective Serotonin Reuptake Inhibitor (SSRI) fluoxetine seems to reduce Glucose-Stimulated Insulin Secretion (GSIS). However, it is unknown whether this effect results from changes in extracellular 5HT concentration owed to the blockade of 5HT transporter (SERT) or from non-5HT dependent actions. The aims of this work were: 1) to quantify extracellular 5HT levels and GSIS in ß-cell lines, 2) to determine whether extracellular 5HT levels and GSIS are changed by fluoxetine or 5-Hydroxytryptophan (5HTP, the immediate 5HT biosynthetic precursor), and 3) to quantify the expression of Slc6a4 gene (encoding SERT) in ß-cell lines in relation to other genes involved in 5HT system. MATERIAL AND METHODS: ß-cell lines MIN6 and RINm5f were subjected to GSIS protocols, after treatment with fluoxetine, 5HTP or 5HT. Insulin and 5HT were quantified by ELISA and HPLC, respectively. Relative mRNA expression was quantified by RT-qPCR. RESULTS: MIN6 ß-cells secretes 5HT in response to glucose, showing a sharp increase in 5HT release when cells were preloaded with 5HTP. Treatment with 5HT or fluoxetine reduces GSIS. Fluoxetine fails to further increases 5HTP-induced elevation of secreted 5HT. MIN6 ß-cells express both isoforms of Tryptophan Hydroxylase (Tph1 and Tph2), and have high expression levels of L-Dopa decarboxylase (Ddc), both enzymes involved in 5HT biosynthetic pathway, but do not express the 5HT transporters Slc6a4 or Slc6a3 (the Dopamine-5HT transporter) genes. CONCLUSION: The inhibitory effect of fluoxetine on ß-cell glucose stimulated insulin secretion is not mediated by blockage of 5HT transporter through SERT.

Linkage disequilibrium between MSX1 and non-syndromic cleft lip/palate in the Chilean population.

Non-syndromic cleft lip/palate (NSCLP) is a complex genetic trait. Linkage and association studies have suggested that a clefting locus could be located on chromosome 4p. Sixty Chilean families were recruited for this study; from these, we used unrelated trios to evaluate the possible linkage disequilibrium between MSX1 and NSCLP. An intragenic marker, MSX1-CA, and an extragenic marker, D4S432 at a distance of 0.8 cM from MSX1, were analyzed by means of polymerase chain-reaction with fluorescent-labeled forward primers, followed by electrophoresis on a laser-fluorescent sequencer. We carried out a transmission/disequilibrium test (TDT) for multiple alleles to evaluate the presence of linkage disequilibrium. Results showed a preferential transmission of the 169-bp allele of MSX1 (p = 0.03). Although there was no preferential transmission for the D4S432 marker, the overall extended TDT (ETDT) showed a significant result (p = 0.01). The authors' findings support the hypothesis of the contribution of MSX1 in the etiology of NSCLP in the Chilean population.

Brain oxygen tension in severe head injury.

OBJECTIVE: Ensuring adequate cerebral oxygenation and perfusion is of fundamental importance in the treatment of patients with acute cerebral disorders. Online continuous monitoring of brain oxygenation is possible with a parenchymal microelectrode that measures local brain oxygen tension. The ultimate question is whether therapeutic approaches can be targeted on the basis of such monitoring. Before this question can be addressed, the technique requires validation in the clinical setting. The frequency of occurrence of low values and its relation to outcome need to be established. METHODS: One hundred one comatose head-injured patients (Glasgow Coma Scale score < or = 8) were studied. Local brain oxygen tension probes were inserted in an undamaged part of the frontal region. Patients were treated in conformance with the European Brain Injury Consortium guidelines. Outcome at 6 months was determined by Glasgow Outcome Scale score. RESULTS: Early brain tissue hypoxia was frequently observed, despite aggressive treatment for intracranial pressure and cerebral perfusion pressure. Values lower than 15 mm Hg, for a duration longer than 30 minutes, were observed in 57 patients. Values lower than 10 mm Hg in 42 patients, and lower than 5 mm Hg in 22 patients, were observed during the first 24 hours. Depth and duration of tissue hypoxia were related to outcome and proved to be an independent predictor of unfavorable outcome and death. CONCLUSION: Monitoring the partial oxygen pressure of local brain tissue is a safe and reliable method for regulating cerebral oxygenation. Because brain tissue hypoxia occurs frequently and is significantly related to poor outcome, future efforts should be aimed at the treatment of brain tissue hypoxia. The effects of such brain hypoxia-targeted treatment need to be established in a multicenter study.

[Case and control study of atypical manifestations in gastroesophageal reflux disease]. / Estudio de casos y controles de manifestaciones atípicas en la enfermedad por reflujo gastroesofágico.

OBJECTIVE: To study the prevalence of atypical symptoms of gastroesophageal reflux disease (GERD) in patients with esophagitis compared to controls. METHODS: We studied consecutive patients who underwent upper endoscopy between January and August of 1997. They were classified in two groups: a) Cases, patients with endoscopic diagnosis of reflux esophagitis, and b) Controls, patients without esophagitis nor typical symptoms of GERD. They answered a questionnaire to evaluate the presence of typical and atypical symptoms of GERD. RESULTS: There were 50 cases and 50 controls. There were no intergroups differences related to gender (p = 0.2), age (p = 0.4), smoking history (p = 0.7) or history of allergic diseases (p = 0.6). The atypical symptoms of GERD were more frequent in cases (66%) than controls (42%) (OR = 2.7%, 95% CI = 1.2-6, p = 0.02). The atypical manifestations more frequent in the cases were hoarseness (OR = 9.3, CI 1.1-77), thoracic pain (4.9, 1.7-14) and globus (2.8, 0.9-9). The presence of atypical symptoms was not associated to the degree of esophagitis (p = 0.7), intensity of typical symptoms (p = 0.2), gender (0.4) or age of patients (p = 0.2). CONCLUSION: Patients with reflux esophagitis have a higher risk to develop extraesophageal disorders of the pharynx, larynx and lungs.

[Gastropathy caused by nonsteroidal anti-inflammatory agents]. / Gastropatía por anti-inflamatorios no esteroideos.

Nonsteroidal anti-inflammatory drugs (NSAID) are widely used in current clinical practice. Several gastric lesions occur as a side effect. This review paper describes the spectrum of gastric lesions, its pathogenesis, prevalence and incidence as well as clinical data, common risk factors, treatment and the prophylaxis of NSAID gastric toxicity.

[Alkaline phosphatase isoenzymes in serum and bronchoalveolar lavage from patients with bronchopulmonary disease]. / Isoenzimas de fosfatasa alcalina en el suero y lavado broncoalveolar de pacientes con patología broncopulmonar.

OBJECTIVE: In this study, we are looking at the principal isoenzymes of alkaline phosphatase (ALP), as injury markers of cellular membranes from bronchial epithelium, in 80 patients diagnosed with bronchopulmonary pathology from different ethology, using serum samples and bronchoalveolar lavage fluid (BAL). METHOD: Patients were grouped according to age as following: 26 preterm neonates suffering respiratory distress syndrome requiring mechanical ventilation; 32 children ranging from 2 to 12 years old, and 22 adults (30-65 years old) examined by bronchoscopy for the purpose of diagnosis. Results obtained from all pathological groups were compared with a control group showing similar characteristics. Isoenzymes were separated by electrophoresis on agarose gel and were quantified by desitometry. Total protein was measured in BAL; ALP activity was expressed in UI/mg x 10-3 of protein. RESULTS: We found that macromolecular ALP fraction was significantly increased in the serum of neonates with distress (p < 0.01), in the patients 2-12 years and adults affected by pulmonary pathology (p < 0.001). The electrophoresis of ALP isoenzymes showed a unique isoenzymatic band corresponding with its macromolecular fraction in the BAL fluid. CONCLUSIONS: We conclude that increased macromolecular fraction of alkaline phosphatase found in the serum of patients diagnosed with respiratory problems could have its origin in damaged pulmonary tissue.

[Acute infectious cholangitis]. / Colangitis infecciosa aguda.

AIM: To know the results in the treatment of acute infectious cholangitis (IAC) and to identify risk factors related to morbidity and mortality. MATERIAL AND METHODS: We reviewed the records of patients with AIC in a 7 year period. Clinical presentation, diagnostic methods and treatment were analyzed. RESULTS: There were 85 cases (61% females and 39% males). Abdominal pain, fever and jaundice were the symptoms most frequently observed. Choledocholithiasis was present in 75% of the cases, malignant obstruction in 12% and other causes in 13%. All patients received antibiotics and 74% underwent any form of biliary drainage. There were complications in 32% of the cases and 14% died. Malignant obstruction was related to high risk of death (OR 11.1). CONCLUSION: The IAC is a potentially life-threatening disease and is most ominous in cases of malignant occlusion of biliary tree.

[Open cholecystectomy in cirrhotic patients. Experience at the Salvador Zubirán National Institute of Nutrition]. / Colecistectomía abierta en pacientes cirróticos. Experiencia en el INNSZ.

AIMS: To inform the morbidity and mortality observed in cirrhotic patients who underwent open cholecystectomy. METHODS: We reviewed the clinical records of 31 cirrhotics that underwent open cholecystectomy and they were compared with a control group of the same age and sex. RESULTS: Despite administration of plasma or vitamin K or both, bleeding and transfusions during surgery were observed more frequently in cirrhotics. The morbidity was 13% in the controls and 42% in the cases. Renal failure, cardiac failure and upper gastrointestinal bleeding were present only in the cirrhotics. Mortality was 16% in this group (one Child A patient and four Child B-C patients). The variable related with major morbimortality was Child B or C classification. CONCLUSIONS: Open cholecystectomy was associated with high morbimortality. The valoration and preparation before surgery must be careful, and the indication from this procedure needs to be made with caution.

[Recommendations for the perinatal management and follow up of late preterm newborns]. / Recomendaciones para el manejo perinatal y seguimiento del recién nacido prematuro tardío.

Prematurity is the main reason for neonatal morbidity and mortality, and has become one of the greatest problems in public health, especially in developed countries. Prematurity rate has increased during the last 2 decades. This increase may be attributed to late preterm babies, that is, those with a gestational age between 34(+0) and 36(+6) weeks. Perinatal morbidities, as well as long term complications, are more frequent in this population than in term babies. The incidence is more similar to the one observed in earlier premature babies. The SEN34-36 group of the Spanish Society of Neonatology suggests these recommendations for the management of late preterm babies. Strategies are offered not only for the early detection of possible complications, but also for the correction of these morbidities, and from the point of view of a family and development centered care. Follow up is strongly recommended due to the high rate of late morbidities.

CO2 reactivity and brain oxygen pressure monitoring in severe head injury.

OBJECTIVE: To investigate the effect of hyperventilation on cerebral oxygenation after severe head injury. DESIGN: A prospective, observational study. SETTING: Neurointensive care unit at a university hospital. PATIENTS: A total of 90 patients with severe head injury (Glasgow Coma Scale score < or =8), in whom continuous monitoring of brain tissue oxygen pressure (PbrO2) was performed as a measure of cerebral oxygenation. INTERVENTIONS: Arterial PCO2 was decreased each day over a 5-day period for 15 mins by increasing minute volume on the ventilator setting to 20% above baseline. Arterial blood gas analysis was performed before and after changing ventilator settings. Multimodality monitoring, including PbrO2, was performed in all patients. Absolute and relative PbrO2/PaCO2 reactivity was calculated. Outcome at 6 months was evaluated according to the Glasgow Outcome Scale. MEASUREMENTS AND MAIN RESULTS: Effective hyperventilation, defined by a decrease of PaCO2 > or =2 torr (0.27 kPa), was obtained in 218 (84%) of 272 tests performed. Baseline PaCO2 averaged 32.3 +/- 4.5 torr (4.31 +/- 0.60 kPa). Average reduction in PaCO2 was 3.8 +/- 1.7 torr (0.51 +/- 0.23 kPa). PbrO2 decreased by 2.8 +/- 3.7 torr (0.37 +/- 0.49 kPa; p < .001) from a baseline value of 26.5 +/- 11.6 torr (3.53 +/- 1.55 kPa). PbrO2/PaCO2 reactivity was low on day 1 (0.8 +/- 2.3 torr [0.11 +/- 0.31 kPa]), increasing on subsequent days to 6.1 +/- 4.4 torr (0.81 +/- 0.59 kPa) on day 5. PbrO2/PaCO2 reactivity on days 1 and 2 was not related to outcome. In later phases in patients with unfavorable outcome, relative reactivity was increased more markedly, reaching statistical significance on day 5. CONCLUSIONS: Increased hyperventilation causes a significant reduction in PbrO2, providing further evidence for possible increased risk of secondary ischemic damage during hyperventilation. The low PbrO2/PaCO2 reactivity on day 1 indicates the decreased responsiveness of cerebral microvascular vessels to PaCO2 changes, caused by generalized vascular narrowing. The increasing PbrO2/PaCO2 reactivity from days 2 to 5 suggests that the risk of compromising cerebral oxygenation by hyperventilation may increase over time.

Brain tissue oxygen response in severe traumatic brain injury.

OBJECTIVE: To investigate clinical relevance and prognostic value of brain tissue oxygen response (TOR: response of brain tissue pO(2) to changes in arterial pO(2)) in traumatic brain injury (TBI). PATIENTS AND METHODS: In a prospective cohort study TOR was investigated in 41 patients with severe TBI (Glasgow Coma Score < or =8) in whom continuous monitoring of brain tissue oxygen pressure (PbrO(2)) was performed.TOR was investigated each day over a five day period for 15 minutes by increasing FiO(2) on the ventilator setting. FiO(2) was increased directly from baseline to 1.0 for a period of 15 minutes under stable conditions (145 tests). In 34 patients the effect of decreasing PaCO(2) was evaluated on TOR by performing the same test after increasing inspiratory minute volume on the ventilator setting to 20% above baseline. Arterial blood gas analysis was performed before and after changing ventilator settings. Multimodality monitoring, including PbrO(2) was performed in all patients. Outcome at six months was evaluated according to the Glasgow Outcome Scale. For statistical analysis the Mann-whitney U-test was used for ordinally distributed variables, and the Chi-square test for categorical variables. Predictive value of TOR was analyzed in a multivariable model. RESULTS: 145 tests were available for analysis. Baseline PbrO(2) varied from 4.0 to 50 mmHg at PaO(2) values of 73-237 mmHg. At FiO(2) settings of 1.0, PbrO(2) varied from 9.1-200 mmHg and PaO(2) from 196-499 mmHg. Three distinct patterns of response were noted: response type A is characterized by a sharp increase in PbrO(2), reaching a plateau within several minutes; type B by the absence of a plateau, and type C by a short plateau phase followed by a subsequent further increase in PbrO(2). Patterns characterized by a stable plateau (type A), considered indicative of intact regulatory mechanisms, were seen more frequently from 48 hours after injury on. If present within the first 24 hours after injury such a response was related to more favorable outcome (p = 0.06). Mean TOR of all tests was 0.73 +/- 0.59 with an median TOR of 0.58. Patients with an unfavourable outcome had a higher TOR (1.03 +/- 0.60) during the first 24 hours, compared to patients with a favorable outcome (0.61 +/- 0.51; p = 0.02). Multiple logistic regression analysis supported the independent predictive value of tissue oxygen response for unfavorable outcome (odds ratio 4.8). During increased hyperventilation, mean TOR decreased substantially from 0.75 +/- 0.54 to 0.65 +/- 0.45 (p = 0.06; Wilcoxon test). Within the first 24 hours after injury a decrease in TOR following hyperventilation was significantly related to poorer outcome (p = 0.01). CONCLUSIONS: Evaluation of TOR affords insight in (disturbances in) oxygen regulation after traumatic brain injury, is of prognostic value and may aid in identifying patients at (increased) risk for ischemia.