Analysis of diagnostic tests in patients with dry eye and hypothyroidism: an observational study

PURPOSE

Colombia is a country with a high prevalence of hypothyroidism, approximately 18.5% compared to the rest of Latin American countries, which is estimated at 10%. That is why in the ophthalmology consultation we find a large proportion of patients with this disease and who also present symptoms of dry eye. When conducting a search in the medical literature, most publications refer to the clinical presentation of dry eye in hyperthyroidism, which is why the main objective of this study is to evaluate tear function tests in the diagnosis of dry eye in patients with hypothyroidism.

METHODS

This is an observational, cross-sectional study carried out in the period between May and December 2019 in the ocular surface unit of the Ophthalmic Technology Center (CTO) in Bogotá. The tests of: OSDI test (Ocular Surface Disease Index), Schirmer type I, tear meniscus height, NiBUT, Osmolarity, Ferning test, Lisamine Green test of 59 patients with Dry Eye Disease (DED) and history of hypothyroidism.

RESULTS

Schirmer type I and NiBUT tests were the parameters that presented the highest percentage of severity, while lissamine green staining and meniscometry showed a tendency to normality.

CONCLUSIONS

The population of this study presents a mixed type dry eye without epithelial cell damage.

Effectiveness of a Weight-Loss Intervention in Preventing Frailty and Functional Decline in Community-Dwelling Obese Older People. A Randomized Controlled Trial

Background: Obesity is a risk factor for frailty and muscle weakness, so weight loss in obese older adults may prevent frailty and functional decline. Objective: To assess the safety and efficacy of a multimodal weight-loss intervention in improving functional performance and reducing frailty risk in obese older adults. Design: Randomized controlled trial with 2 parallel arms. Setting and participants: Community-dwelling obese adults aged 65-75 years with body mass index (BMI) 30-39 kg/m2. Intervention: 6-month multimodal intervention based on diet and a physical activity program. Control group: Usual care. Main and secondary outcome measures: Frailty (Fried criteria) rate and functional performance at 6, 12, and 24 months of follow-up, respectively. Intermediate outcome measures: Weight loss, body composition changes, and metabolic and inflammatory biomarker changes. Results: N=305. The study intervention increased gait speed at 12 and 24 months of follow-up, but had no significant effect on frailty prevention. It was effective in reducing weight, BMI, fat mass, interleukin 6, and insulin resistance and improving self-reported quality of life. Conclusions: The study intervention was not demonstrated to be effective in preventing frailty in obese people aged 65-75 years at 24 months of follow-up. However, it allowed weight loss and a reduction in inflammatory and insulin resistance markers, which could have a long-term effect on frailty that requires further research.

Continuous presence of females in estrus does not prevent seasonal inhibition of LH and androgen concentrations in bucks

In male goats, being in permanent visual contact with females in estrus does not prevent seasonal variation in certain endocrine hormone levels and sexual activities. In this study, we tested whether continuous and full contact with females in estrus prevented seasonal endocrinological variation in bucks. In 1 experiment (Exp. 1), we verified that the sudden introduction of goats in estrus increased the plasma concentrations of androgen in bucks during the nonbreeding season under our experimental conditions. In another experiment (Exp. 2), we tested the ability of estrous goats to prevent seasonal inhibition of LH and androgen secretions in bucks kept in permanent and full contact with them. In Exp. 1, 3 groups of bucks (n = 5 in each group) were isolated from females from the months of July to January. On January 27, one group continued being isolated from females; a second group was exposed to ovariectomized, untreated goats; and a third group was exposed to ovariectomized goats with induced estrus. Plasma androgen concentrations were determined every 2 h from 8 h before to 8 h after the introduction of females. The introduction of estrus-induced goats significantly increased androgen concentrations, which were higher than in the isolated bucks, as well as in those exposed to untreated goats (P < 0.05). In Exp. 2 (n = 5 per group), one group of bucks was isolated from females from October to July, whereas two other groups remained in contact with ovariectomized goats, either untreated or regularly induced to estrus. In the three groups of bucks, plasma concentrations of LH were determined once during the months of October, February, March, and June, whereas androgen concentrations were determined weekly from October to July. The mean plasma LH and androgen concentrations were low and did not differ among the groups of bucks during the normal seasonal period of sexual inactivity (P > 0.05). We conclude that full contact and sexual interactions with estrus-induced goats failed to stop the seasonality of LH and androgen plasma concentrations of bucks, although bucks could respond to the introduction of females by acute increases in plasma LH and androgen.

Total Body Water and Intracellular Water Relationships with Muscle Strength, Frailty and Functional Performance in an Elderly Population

BACKGROUND

As a person ages, total body water (TBW), intracellular water (ICW), muscle mass and muscle strength tend to decline. The decline in ICW may reflect losses in the number of muscle cells but may also be responsible for less hydrated muscle cells.

AIM

To assess whether TBW and ICW are associated with muscle strength, functional performance and frailty in an aged population, independently of muscle mass.

METHODOLOGY

Design: An observational cross-sectional study of community-dwelling individuals aged 75 years and older. TBW, ICW, fat mass, lean mass and muscle mass were assessed by bioelectrical impedance analysis, frailty status was measured according to Fried criteria, handgrip strength was measured using the hand-held JAMAR dynamometer, and functional performance was measured according to the Barthel index and gait speed.

RESULTS

A total of 324 subjects were recruited (mean age 80.1 years, 47.5% women). TBW and ICW were closely correlated with muscle mass in both sexes. ICW was also associated with Barthel score, gait speed and frailty in both sexes and with handgrip in men. Considerable variability in ICW was observed for the same muscle mass. Multivariate analysis showed a positive effect of ICW on handgrip, functional performance and gait speed and a protective effect of ICW on frailty, independently of age, sex, body mass index and number of comorbidities.

CONCLUSIONS

In elderly individuals with similar muscle mass, those with higher ICW had a better functional performance and a lower frailty risk, suggesting a protective effect of cell hydration, independently of muscle mass.

Alimentación de ovinos con heno de avena cosechado en dos etapas de madurez en el noroeste de Chihuahua, México

Manipular la variedad y la etapa de madurez al corte del heno de avena (Avena sativa L.), puede mejorar el valor nutricional del forraje y por tanto la respuesta productiva de los animales. Se evaluó el efecto de la alimentación de corderas con heno de tres variedades de avena, cosechadas en dos etapas de madurez. El estudio se llevó a cabo en el noroeste del estado de Chihuahua, México. La hipótesis fue que la avena cosechada en madurez fisiológica presenta mayor proporción de grano lo que mejora el valor nutritivo del forraje y la ganancia de peso en las corderas. Las variedades de avena evaluadas fueron Cuauhtémoc, Menonita y Bachíniva. Las avenas fueron cosechadas para heno en las etapas de grano lechoso-masoso (L-Masoso) y madurez fiológica (M-Fisiológica). Se usaron 72 corderas (21,2 ± 3,7 kg), que fueron agrupadas por peso y alimentadas ad libitum durante 63 d, con una ración compuesta de 65 % heno de avena y 35 % concentrado. El diseño fue en bloques completos al azar con arreglo factorial 3 x 2 entre variedad y etapas de madurez. La composición química de los forrajes fue similar entre las variedades de avena. No se observó efecto de variedad ni etapa de madurez sobre el comportamiento productivo de las corderas. El consumo de materia seca, la ganancia diaria de peso y la conversión alimenticia en L-Masoso y M-Fisiologica fueron 1,03 y 1,01 kg, 119 y 130 g, y 9,6 y 8,9 kg a-1 d-1, respectivamente. La falta de respuesta en los animales se atribuyó a la composición química similar que presentaron los forrajes. Aunque la avena cosechada en L-Masoso mejoró (P

Contreo en surco y etapa de madurez sobre la producción y calidad del forraje de variedades de avena

El déficit hídrico es uno de los principales factores que limitan la producción de forrajes en las zonas áridas y semiáridas del mundo. Nuestra hipótesis fue que el sistema de labranza de captación de agua surcos con contras (SCC), podría incrementar el rendimiento de forraje de avena (Avena sativa L.), y que cosechar el forraje en la etapa de madurez fisiológica mejora su calidad. Del año 2005 al 2007, se midió el efecto del sistema de siembra: surcos con contras (SCC) y la etapa de madurez al corte: grano lechoso masoso (LM) y madurez fisiológica (MF), sobre el rendimiento y calidad de forraje, de cinco variedades de avena, establecidas bajo condiciones de temporal, en el noroeste del estado de Chihuahua, México, El diseño fue parcelas sub-subdivididas en bloques completos al azar, la parcela grande fue el sistema de siembra, la mediana la etapa de madurez al corte, y la parcela chica la variedad, los sitios (n=14) fueron las repeticiones. La composición química y la materia seca digestible (MSD) del heno de avena fueron medidas, sin tomar en cuenta el efecto de sistema de siembra SCC. La producción de materia seca fue 8,7 % mayor (P0,05) con 9,50 y 9,20 %; la fibra detergente neutro varío (P

Characterization of the cross-neutralizing antibody response against hepatitis C virus in the liver transplantation setting

Neutralizing antibody (nAb) activity during the course of natural infection is believed to be crucial to combating virus propagation. The aim of this study was to measure the impact of nAb response on HCV early kinetics and genetic evolution in the liver transplantation (LT) setting. A cohort of 28 patients undergoing LT for HCV-related cirrhosis was included in the study. Viral load, nAb titers and hypervariable region 1 (HVR1) sequences were determined in serum samples obtained before and at different time points after LT. Serum nAb titers were assessed using HCV pseudoparticles (HCVpp). HVR1 sequences were obtained by direct sequencing. Patients were classified according to viral kinetic patterns (plateau or increasing), during the first week after LT. All patients demonstrated high titers of nAbs before LT, although this was not associated with early kinetic patterns or HVR1 evolution during the first week after LT. We found that in patients with plateau HCV early kinetics, the virus required adaptive mutations, while in those with increasing viral loads, the HVR1 region remained largely conserved (p = 0.015). These data suggest that HCV adaptation via selection of the best-fitted variants may account for early viral kinetics following LT.

Hemagglutinating activity of Gallibacterium strains

In the present study, the hemagglutinating activity of seven reference strains, and nine Mexican and three Danish field isolates, of Gallibacterium was investigated by using fresh erythrocytes of 19 different types including chicken (broiler, rooster, layer hen), turkey, pigeon, quail, duck, Harris's hawk (Parabuteo unicinctus), house finch (Carpodacus mexicanus), cow, sheep, horse, dog, rabbit, pig, and human (groups A, B, AB, and O; Rh+). Agglutination was observed for broiler chicken, layer hen, quail, rabbit, and pig erythrocytes with a subset of Gallibacterium strains, whereas most tested strains agglutinated rabbit erythrocytes. Transmission electron microscopic examination of a hemagglutinating strain demonstrated a close interaction between the bacterial and erythrocyte surfaces. The results indicate that some Gallibacterium strains are able to agglutinate avian or mammalian erythrocytes, or both. However, the mechanisms enabling hemagglutination are not known and will be addressed in future studies.

Evolution of the NS3 and NS5B regions of the hepatitis C virus during disease recurrence after liver transplantation

In patients with hepatitis C virus (HCV)-related cirrhosis, infection recurrence is universal after liver transplantation (LT). The relevance of host and virus-related factors on the outcome of hepatitis C recurrence is poorly understood. This study analyzed the relationship between the genetic evolution of the Non-Structural (NS)3 protease and NS5B polymerase regions of HCV and the severity of hepatitis C recurrence. Thirty-three patients were classified as having mild (n = 16) or severe recurrence (n = 17), according to the degree of fibrosis in liver biopsies obtained 1 year after transplantation. Viral load and consensus sequences of the NS3 and NS5B domains were determined in a pre-LT and in four post-LT sequential serum samples. At week 12 after LT, viremia was significantly higher in patients with severe recurrence. NS3 and NS5b regions evolved independently after LT. The genetic evolution of NS3 domain was not related to the severity of the recurrence. However, the diversification in the NS5B region later than 12 weeks after LT was greater in patients with mild than in those with severe recurrence, suggesting a stronger immune pressure in the first group. These observations highlight the complex interplay between viral evolution and clinical outcomes in the LT setting.

[Factors associated to the visiting time in patients with ischaemic cerebrovascular disease]

INTRODUCTION

The high prevalence of cerebrovascular disease in underdeveloped countries has made it a public health issue. Establishing therapy within the first three hours in the case of patients with cerebrovascular disease has proved to have beneficial effects on the patient.

AIM

To identify the factors associated with the time taken to visit the hospital emergency department by patients with ischaemic cerebrovascular disease in the population of Colombia.

PATIENTS AND METHODS

We conducted a cross-sectional analytical study that included patients over 18 years old who had been clinically diagnosed as having an acute ischaemic cerebrovascular disease. The time between onset of symptoms and admission to the emergency department was estimated and then related to sociodemographic and cultural factors and the severity of the clinical features.

RESULTS

The mean time taken to visit hospital was 17 hours and 48 minutes (standard deviation: 24 hours and 12 minutes). In 22.8% of cases the patient was admitted within the first three hours. Patients who were covered by the subsidised health care system and came from low socioeconomic classes, together with those from rural areas took longer to visit (p < 0.005). The values on the United States Institute of Health scale did not have any relation to visiting times.

CONCLUSIONS

The time that elapses between the presentation of the cerebrovascular disease and visiting the emergency department in the Colombian population is high, especially among the population with lower levels of income and schooling. There is a need to implement models of education targeted towards the community and focused on the early identification of signs, symptoms and impact of cerebrovascular disease, as well as to set up a system of health care that prevents delays by coordinating resources both inside and outside hospitals.

Ecotoxicological evaluation of diesel-contaminated soil before and after a bioremediation process

Evaluation of contaminated sites is usually performed by chemical analysis of pollutants in soil. This is not enough either to evaluate the environmental risk of contaminated soil nor to evaluate the efficiency of soil cleanup techniques. Information on the bioavailability of complex mixtures of xenobiotics and degradation products cannot be totally provided by chemical analytical data, but results from bioassays can integrate the effects of pollutants in complex mixtures. In the preservation of human health and environment quality, it is important to assess the ecotoxicological effects of contaminated soils to obtain a better evaluation of the healthiness of this system. The monitoring of a diesel-contaminated soil and the evaluation of a bioremediation technique conducted on a microcosm scale were performed by a battery of ecotoxicological tests including phytotoxicity, Daphnia magna, and nematode assays. In this study we biostimulated the native microflora of soil contaminated with diesel by adding nutrients and crop residue (corn straw) as a bulking agent and as a source of microorganisms and nutrients; in addition, moisture was adjusted to enhance diesel removal. The bioremediation process efficiency was evaluated directly by an innovative, simple phytotoxicity test system and the diesel extracts by Daphnia magna and nematode assays. Contaminated soil samples were revealed to have toxic effects on seed germination, seedling growth, and Daphnia survival. After biostimulation, the diesel concentration was reduced by 50.6%, and the soil samples showed a significant reduction in phytotoxicity (9%-15%) and Daphnia assays (3-fold), confirming the effectiveness of the bioremediation process. Results from our microcosm study suggest that in addition to the evaluation of the bioremediation processes efficiency, toxicity testing is different with organisms representative of diverse phylogenic levels. The integration of analytical, toxicological and bioremediation data is necessary to properly assess the ecological risk of bioremediation processes.

[Trans-surgical ablation of atrial flutter in patients treated with closure of atrial septal defect. Pilot project]

Atrial flutter is one of the most common arrhythmias in patients with atrial septal defect, after surgery 14% of patients can develop it and may be associated with high morbidity. In this study we performed prophylactic and therapeutic ablation of atrial flutter during atrial septal closure surgery drawing 4 lines; line 1, isthmus cavo-tricuspid, the area between the inferior vena cava and the tricuspid ring; line 2, the area between coronary sinus ostium and inferior vena cava; line 3, the area between tricuspid valve annulus and coronary sinus ostium; and line 4, the area between lateral atriotomy and atrial septal defect. Twenty-one patients were included, 6 (28.5%) patients had atrial flutter before surgery and 15 (71.4%) were in sinus rhythm. There were no new cases of atrial flutter, but at six months follow up 2 (33.3%) patients recidivated with atrial flutter. One patient developed high degree atrio-ventricular block and a pacemaker had to be implanted. Older age at the time of surgery and high systolic pulmonary pressure were significantly higher in those patients with atrial flutter before surgery and in patients with arrhythmias recurrence. Ablation of atrial flutter during atrial septal closure surgery can be a good option for the treatment and prevention of atrial arrhythmias, but more studies are still needed.

Two nitrate/nitrite transporters are encoded within the mobilizable plasmid for nitrate respiration of Thermus thermophilus HB8

Thermus thermophilus HB8 can grow anaerobically by using a membrane-bound nitrate reductase to catalyze the reduction of nitrate as a final electron acceptor in respiration. In contrast to other denitrifiers, the nitrite produced does not continue the reduction pathway but accumulates in the growth medium after its active extrusion from the cell. We describe the presence of two genes, narK1 and narK2, downstream of the nitrate reductase-encoding gene cluster (nar) that code for two homologues to the major facilitator superfamily of transporters. The sequences of NarK1 and NarK2 are 30% identical to each other, but whereas NarK1 clusters in an average-distance tree with putative nitrate transporters, NarK2 does so with putative nitrite exporters. To analyze whether this differential clustering was actually related to functional differences, we isolated derivatives with mutations of one or both genes. Analysis revealed that single mutations had minor effects on growth by nitrate respiration, whereas a double narK1 narK2 mutation abolished this capability. Further analysis allowed us to confirm that the double mutant is completely unable to excrete nitrite, while single mutants have a limitation in the excretion rates compared with the wild type. These data allow us to propose that both proteins are implicated in the transport of nitrate and nitrite, probably acting as nitrate/nitrite antiporters. The possible differential roles of these proteins in vivo are discussed.

[Double inlet left ventricle. Morphopathology and surgical anatomy]

Because of the possibility of surgical treatment of double inlet left ventricle, its basic morphologic features of surgical and imaging importance are analyzed. Seventeen hearts were studied with the segmental sequential system. The situs was solitus in thirteen; dextroisomerism in three and levoisomerism in one. The atrioventricular valves were separated in nine; there was a common atrioventricular valve in eight; straddling of the atrioventricular valve in seven and stenosis in two. The rudimentary right ventricle was to the right side in twelve hearts and to the left side in five. The discordant ventriculoarterial connection was the most frequent (seven), followed by the concordant one (five) and double outlet right ventricle (five). There was pulmonary stenosis in five. The ventricular septum did not reach the crux cordis. The ventricular septal defect was bigger in straddling atrioventricular valves than in valves completely open into the left ventricle, being restrictive in ventriculoarterial concordance. Surgical treatment varies as the complexity of this cardiopathy does, from cardiac septation to palliation procedures. The morphologic knowledge of this cardiac malformation is basic to interpret correctly the diagnostic imaging.

[Permanent rhythm and conduction disorders in patients surgically treated for atrial septal defect]

Atrial septal defect (ASD) represents a congenital heart disease with good prognosis, however, atrial arrhythmias are well-documented complications. A retrospective study was performed to assess the prevalence, types and risk factors of arrhythmias in patients with ASD after surgical correction. 920 patients were analyzed retrospectively; cases with complex congenital heart disease or another systemic alteration conditioning atrial rhythm disturbances were excluded. 460 patients with ASD corrected by surgery were followed at least for six months after the procedure. 29.3% of patients were male and 70.7% female. Direct closure was performed in 63%, pericardial patch was installed in 27%. 29 patients (6.3%) had conduction and rhythm disturbances before surgery, the most common arrhythmias were atrial flutter (34.5%), first degree A-V block (31%) and low right atrial rhythm (27.6%). Six months after atrial defect closure, 65 patients (14.13%) had arrhythmias, 44.6% atrial flutter, 20% ectopic atrial rhythm, 10.8% sick sinus syndrome. The risk of atrial arrhythmias was related to age at surgical repair, pulmonary hypertension and atrial arrhythmias before surgery.

[Coronary revascularization without extracorporeal circulation. An alternative therapy (preliminary report)]

Direct myocardial revascularization techniques has earned great acceptance in the treatment of ischemic coronary syndromes in the past two decades. Almost since its beginnings the procedure was done with the aid of extracorporeal circulation, since the technical accessibility with cardiac standstill further helped to evolve the procedure. As years went by, complications due to the use of the pump became evident, such as microembolism, bleeding disorders, and others. Besides this, there is a special group of patients, those with high surgical risk, with preexisting pulmonary, hepatic or cerebral disease, who benefit a great deal when bypass grafting procedure is done without the pump. In this article we delineate the indications, contraindications, and the procedure itself based in our personal experience, reporting our first five patients with this technique.

[Coxiella burnetii endocarditis. A report of the first case diagnosed in Mexico]

The first case of Q fever endocarditis that has been diagnosed in Mexico is presented. A 10-year-old girl with discrete subaortic stenosis (SAS) and patent ductus arteriosus (PDA) was seen in December of 1996 with fever, hepatomegaly and splenomegaly. She presented also anemia, leukopenia, hypergammaglobulinemia, positive rheumatoid factor, cryoglobulinemia, antinuclear and anticytoplasmic antibodies (anti-RNA-proteins and anti-DNA). An aortic valve vegetation was seen by echocardiogram. Blood-cultures were negative. Antibody test for Coxiella burnetii was positive. Treatment with doxicyclin was initiated as soon the diagnosis was done. PDA was closed, SAS was liberated and two aortic vegetations were resected. Endocarditis in Q fever occurs when there is predisposing heart disease and/or immunodeficiency. Effective therapy has not yet been established. The diagnosis of Q fever endocarditis is difficult; it should be considered, in case of clinical suspicion of endocarditis with negative blood-cultures.

[Endocarditis due to an alga of the genus Prototheca sp. A saprophyte of water and of tree sap?]

We report a case of a preterm neonate with very low birth weight (775 grs), He stayed 77 days in a neonatal care unit due to respiratory distress syndrome, with respiratory support for 27 days, and complications in gastrointestinal and nervous systems. In a structural normal heart, he developed infective endocarditis that was treated with good bacteriologic results. An echocardiogram showed the persistence of a mass in the right atrium, the mass was a thrombus and it was resected. Histopathological analysis and cultures of the thrombus reported Prototheca sp. that is an algae. The patient received medical treatment with amphothericin B with satisfactory clinical evolution. He is doing well 6 months later. This is the first report of literature of an algae causing endocarditis.

Prevalence of phenotypic activated protein C resistance (APCR) in venous thromboembolic patients

Until the discovery of activated protein C resistance (APCR), less than 10% of patients with venous thromboembolism (VT) showed defects in proteins involved in the inhibition of coagulation. APCR is caused by a single point mutation in the factor V gene, and it is accepted that APCR is associated with an increased risk for VT. In this work, we studied the prevalence of APCR in venous thromboembolic patients and found it to be 10.5% compared with 4.5% in controls (p = 0.105).

[The radiofrequency ablation of Mahaim and Kent fibers during the repair of Ebstein's anomaly]

A young man 20 years old was referred to the Institute with Ebstein anomaly. He had experienced palpitations since the age of eight. Those episodes occurred several times a year. During the electrophysiologic study a regular antidromic reciprocating tachycardia was induced using a right atriofascicular connection (Mahaim). The atrial insertion of the Mahaim fibers was in the right posterolateral atrium. Also another orthodromic supraventricular tachycardia was induced with anterograde conduction over atrioventricular node and retrograde conduction over to canceled atrioventricular right posteroseptal bypass tract (Kent). During surgery to repair Ebstein anomaly we decided to perform radiofrequency catheter ablation of both Mahaim and Kent fibers at the tricuspid annulus in the posteroseptal and lateral regions, eliminating accessory pathways conduction. There were no complications during the procedure. The tachycardia has not recur in a six months period of follow up. No antiarrhythmic drugs has been given.

[The usefulness of electrophysiology in a patient undergoing cardiomyoplasty]

The cardiomyoplasty is a new surgical procedure that uses a skeletal muscle electrostimulated in order to reinforce or even substitute partially the cardiac muscle. We present the electrophysiology aspects in a patient with dilated cardiomyopathy that underwent cardiomyoplasty. First the latissimus dorsi muscle was prepared with a neurostimulant ITREL II. During the surgical procedure a dual-chamber pacemaker mode DDD brand CPI was placed. After three months, ablation radiofrequency of the AV node was performed in order to control the atrial fibrillation that caused heart failure. By means of the AV block we obtained synchrony between the ventricular stimulation and the latissimus dorsi muscle, and by this the patient improved. Using the modern pacemakers and radiofrequency we can control the bradyarrhythmias as well as the tachyarrhythmias frequent in patients with dilated cardiomyopathy, increasing the success rate of cardiomyoplasty.

[Atrioventricular and ventriculoatrial conduction in patients operated on for the Wolff-Parkinson-White syndrome]

Over the last decade the surgical treatment of the Wolff-Parkinson-White syndrome has been well accepted. It is important to make an early diagnosis for surgical success. For this purpose we utilized programmed electrical stimulation to assess the functional characteristics of atrioventricular and ventriculoatrial conduction in our post-operative patients. In 55% of the cases we found accelerated nodal conduction. Programmed electrical stimulation correctly identified 90% of successfully treated patients. We did not found any false positive curve, therefore, this method has a high specificity. We concluded that in post-operative patients with the Wolff-Parkinson-White syndrome: 1- There is a high incidence of accelerated nodal conduction and 2- programmed electrical stimulation can correctly identify most of the patients who were successfully treated.

[Surgical resection of a focus of ventricular tachycardia guided by endocardial and epicardial mapping]

We describe a case of a 46 years old female with chagasic heart disease. In one year she presented six episodes of sustained ventricular tachycardia, heart rate 230 beats per minute, morphology of RBBB AQRS -60 degrees, with hemodynamic deterioration that needed electrical cardioversion. She was treated with several antiarrhythmic drugs but not good response was obtained. Programmed electrical stimulation was done and it show three different types of ventricular tachycardia, trough pace-mapping the site of the clinical tachycardia was located in the portion inferior and inferior-posterior of the left ventricle that was confirmed by entrainment. Epicardial mapping was performed in 38 ventricular sites following the modified Harken sketch and the location of the site of outlet was confirmed in the posterior base of the left ventricle, at this point the surgical resection was done with no complication. The results were satisfactory. Eight days later programmed electrical stimulation was done and the ventricular tachycardia could not be induced. Six months afterwards the patient is asymptomatic without medical treatment.

[Surgical treatment of supraventricular tachycardias (Wolff Parkinson White and Occult Kent). Experience at the "Ignacio Chávez" National Institute of cardiology]

We report our initial experience in the surgical section of the accessory pathway in thirteen patients: eight patients with Wolff Parkinson White syndrome and five with accessory pathway functioning only in direction ventricle to atrium (Kent concealed), with recurrent episodes of paroxysmal supraventricular tachycardia with no response to medical treatment. Three of these patients had episodes of auricular fibrillation with interval RR lower than 250 msec and one patient presented syncope. A total of fifteen accessory pathways were sectioned: 7 left lateral, 5 left posterior, one left posterolateral, one right lateral, and another one right anteroseptal. In the same procedure two patients had correction of another heart malformation: one with patent ductus arteriosus and another with and another with atrial septal defect. All patients had successful outcome, one of them needed a second surgery for persistent accessory pathway. We had two post-operatory complications: one mediastinitis and one patient with ectopic auricular tachycardia.

[Enterotoxigenic Staphylococcus aureus and thermonuclease: risk indicators of staphylococcal poisoning with milk products]

We examined 159 samples of milk and milk products for staphylococcal count and presence of thermonuclease. Highest count for S aureus was found in cheese, followed by raw milk. Enterotoxins, mostly A and D, were found in 32% of 34 S aureus strains isolated from cheese and milk. Thermonuclease was detected in dried milk and cheese. Identification of this enzyme is a good method to evaluate risk of food poisoning from S aureus contamination.