High frequency properties of a planar ion trap fabricated on a chip.

We report on the measurement of the high frequency properties of a planar Penning ion trap fabricated on a chip. Two types of chips have been measured: the first manufactured by photolithographic metal deposition on a p-doped silicon substrate and the second made with printed circuit board technology on an alumina substrate. The input capacitances and the admittances between the different trap's electrodes play a critical role in the electronic detection of the trapped particles. The measured input capacitances of the photolithographic chip amount to 65-76 pF, while the values for the printed circuit board chips are in the range of 3-5 pF. The latter are small enough for detecting non-destructively a single trapped electron or ion with a specifically tuned LC resonator. We have also measured a mutual capacitance of ∼85 fF between two of the trap's electrodes in the printed circuit board chip. This enables the detection of single, or very few, trapped particles in a broader range of charge-to-mass ratios with a simple resistor on the chip. We provide analytic calculations of the capacitances and discuss their origin and possible further reduction.

Cell-autonomous regulation of cell and organ growth in Drosophila by Akt/PKB.

Organismal size is determined by a tightly regulated mechanism that coordinates cell growth, cell proliferation and cell death. The Drosophila insulin receptor/Chico/Dp110 pathway regulates cell and organismal size. Here we show that genetic manipulation of the phosphoinositide-3-OH-kinase-dependent serine/threonine protein kinase Akt (protein kinase B) during development of the Drosophila imaginal disc affects cell and organ size in an autonomous manner. Ectopic expression of Akt does not affect cell-fate determination, apoptosis or proliferation rates in imaginal discs. Thus, Akt appears to stimulate intracellular pathways that specifically regulate cell and compartment size independently of cell proliferation in vivo.

The translational inhibitor 4E-BP is an effector of PI(3)K/Akt signalling and cell growth in Drosophila.

The initiation factor 4E for eukaryotic translation (eIF4E) binds the messenger RNA 5'-cap structure and is important in the regulation of protein synthesis. Mammalian eIF4E activity is inhibited when the initiation factor binds to the translational repressors, the 4E-binding proteins (4E-BPS). Here we show that the Drosophila melanogaster 4E-BP (d4E-BP) is a downstream target of the phosphatidylinositol-3-OH kinase (PI(3)K) signal-transduction cascade, which affects the interaction of d4E-BP with eIF4E. Ectopic expression of a highly active d4E-BP mutant in wing-imaginal discs causes a reduction of wing size, brought about by a decrease in cell size and number. A marked reduction in cell size was also observed in post-mitotic cells. Expression of d4E-BP in the eye and wing together with PI(3)K or dAkt1, the serine/threonine kinase downstream of PI(3)K, resulted in suppression of the growth phenotype elicited by these kinases. Our results support a role for d4E-BP as an effector of cell growth.

[High retention of (99m)Tc-MIBI in delayed phase as a pitfall in the combined parathyroid-thyroid scintigraphy]. / Intensa retención de (99m)Tc-MIBI en la fase tardía como causa de error diagnóstico en la gammagrafía combinada paratiroides-tiroides.

Dual phase parathyroid scintigraphy with (99m)Tc-sestaMIBI is a very sensitive technique in the preoperative localization and diagnosis of parathyroid adenoma. However, pitfalls have been reported in patients with thyroid nodules with MIBI uptake or with previous thyroid surgery. To solve this problem, a thyroid scintigraphy with (99m)Tc-pertechnetate is usually performed following the parathyroid study. Occasionally, as in our patient the parathyroid lesion may show high MIBI uptake and delayed washout that interfere with the subsequent thyroid scintigraphy giving the false appearance of a pertechnetate avid lesion. This has been called the «shine through¼ effect. To avoid it, the parathyroid and thyroid scintigraphies can be performed on separate days. We have also found it useful to compare our results with that of ultrasound and fine needle aspiration puncture with measurement of the parathyroid hormone (PTH) and thyroglobulin in the aspirated material.

[Modifications of the glucose curves and gastric voiding of children with Dumping syndrome after laparoscopic Nissen surgery]. / Modificaciones de las curvas de glucemia y vaciamiento gástrico de los niños con síndrome de dumping tras cirugía de nissen laparoscópico.

INTRODUCTION: There has been an important evolution of surgical treatment in recent years due to the progressive generalization of laparoscopic surgery. All of the available techniques can be done laparoscopically with similar results to those of open surgery. In 1978, Villet et al. described the Dumping syndrome (DS) as a frequent complication of Nissen fundoplication. DS is a group of signs and symptoms that appear shortly after surgery, including abdominal pain, paleness, sweating, diarrhea, nausea, even weight loss. These symptoms can be differentiated into early dumping that occurs between 30 to 60 minutes after eating and late dumping that occurs 92-240 minutes after the postprandial period. MATERIAL AND METHODS: A total of 8 patients (3 boys and 5 girls) have been studied. Their ages ranged from 3 to 12 years (mean 9 years), and they were diagnosed of dumping syndrome after performing the laparoscopic Nissen-Rossetti. All underwent a gastric voiding study by scintigraphy after administration of a volume of milk adjusted to their weight labeled with 99Tc-DTPA and oral glucose overload test with 1.75 g/kg of glucose, determining the baseline glycemia and every 30 minutes post-intake, at 0, 30 and 90 minutes. Insulin was also measured to obtain the glucose/insulin ratio. This study was conducted for all patient diagnosed of dumping syndrome before and after laparoscopic Nissen-Rossetti surgery. RESULTS: The following results were obtained: Glucose Curve: 1. Maximum glycemia. PreNissen. The mean of the maximum glycemia values before surgery was 133.9+/-32.11 mg/dl. Post-Nissen. Mean maximum glycemias after surgery was 208.5 +/- 45.07 mg/dl with a range of 147-276 mg/dl. These differences of maximum glycemia were clearly significant with a p <0.002. Minimum glycemia. The mean value of the minimum glycemias after the surgery, compared with the previous value, did not show significant differences: 62.6+/- 11.51 mg/dl versus 71.8 +/- 28.04 mg/dl. Glucose/insulin ratio. The hyperinsulinism values after the intervention studied by means of the glucose/insulin ratio were abnormal in 70.5% (defined as ratio under 3). The mean value was also characteristic of hyperinsulinism (2.3 +/- 1.62). The mean value of the coefficient prior to the surgery was 4.6 with a deviation of 3.04, the differences not being statistically significant with a p= 0.097. Measurement of gastric voiding: The T1/2 (decay) value in post-Nissen patients was significantly lower than in pre-Nissen patients. The postsurgical mean and standard deviation was 29.74 +/- 7.92 min, while in the presurgical group, the mean and standard deviation was 73.75 +/- 28.34 min with p< 0.011; statistically significant. CONCLUSIONS: From the values obtained, we can state that a significant increase in maximum glycemia has been found in all children after surgery who were diagnosed of dumping syndrome and a significant decrease in the mean time of gastric voiding and therefore an increase in the acceleration of gastric voiding after the performance of the Nissen regarding the previous values. The dumping syndrome is a frequent side effect that we must keep in mind in patients who have been previously operated for anti-reflex surgery, the symptoms being greater in most of the transitory cases. Furthermore, it is important to keep in mind because it has an easy treatment that reverts the symptoms in a short time

A pilot experience launching a national dose protocol for vascular and interventional radiology.

The design of a national dose protocol for interventional radiology has been one of the tasks during the European SENTINEL Coordination Action. The present paper describes the pilot experience carried out in cooperation with the Spanish Society on Vascular and Interventional Radiology (SERVEI). A prospective sample of procedures was initially agreed. A common quality control of the X-ray systems was carried out, including calibration of the air kerma area product (KAP) meters. Occupational doses of the radiologists involved in the survey were also included in the survey. A total of 10 Spanish hospitals with interventional X-ray units were involved. Six hundred and sixty-four patient dose data were collected from 397 diagnostic and 267 therapeutic procedures. Occupational doses were evaluated in a sample of 635 values. The obtained KAP median/mean values (Gy.cm2) for the gathered procedures were: biliary drainage (30.6/68.9), fistulography (4.5/9.8), lower limb arteriography (52.2/60.7), hepatic chemoembolisation (175.8/218.3), iliac stent (45.9/73.2) and renal arteriography (39.1/59.8). Occupational doses (mean monthly values, in mSv) were 1.9 (over apron); 0.3 (under apron) and 4.5 (on hands). With this National experience, a protocol was agreed among the SENTINEL partners to conduct future similar surveys in other European countries.

[Vitamin intake in the adult population of the Andalusian Autonomous Community]. / Ingesta de vitamina A en la población adulta de la Comunidad Autónoma Andaluza.

BACKGROUND: The aim of this study was to know the intake of vitamin A of the Andalusian population and its distribution by gender and age. STUDY SETTING: The sample size was 3680 healthy individuals, from both genders, residents and registered at census of the Autonomous Community of Andalusia, with a multi-step, stratified and probabilistic study. SUBJECTS: Men and women with ages between 25-60 years, both included. INTERVENTIONS: By means of a personal interview, health habits of the individuals interviewed were gathered, and a dietary questionnaire was undertaken, which consisted, in the first place, of a 48-hour remembering analyzing dietary intake of each selected individual determining not only the type and quantity of foods consumed but also the way of cooking them and other ingredients, and distributing them according to the different daily meals. RESULTS: Mean Vitamin A intake in Andalusia is 800,63 mg/day. Men have greater intake than women, although the values for both genders are under the recommended (RI) ones. Vitamin A intake decreases with age in men, whereas in women the age group 50-69 years is the one having the lowest intake. 8,84% of women and 15,22% of men have intakes lower than 1/3 of de RI, which may be considered a high risk factor. The percentages of individuals having a likely risk of inadequate vitamin A ingestion (values lower than 2/3 of RI) are considerably high among the Andalusian population. CONCLUSIONS: Mean global intake of vitamin A in Andalusia is acceptable although about 40% of the population may be at risk of inappropriate ingestion, this condition being more pronounced for men.

[Differences between the neuropsychological profiles of Asperger's syndrome and non-verbal learning disorder]. / Diferencias entre los perfiles neuropsicológicos del síndrome de Asperger y del sindrome de dificultades de aprendizaje no verbal.

INTRODUCTION: The validity of the Asperger syndrome (AS) diagnose continues to be debated due to the lack of consensus on its definition, specially regarding higher-functioning autism. Previous research has suggested that the neuropsychological profile of the non verbal learning syndrome (NVLS) might be utilized to sustain a differential diagnose of the AS with other diseases associated with development. AIM: To analyze the neuropsychological profile of children diagnosed with AS and compare with those obtained from children with NVLS. SUBJECTS AND METHODS: All cognitive domains from 15 children have been evaluated with an extensive variety of tests; 5 were diagnosed with AS and 5 with NVLS, all of them submitted to the Nino Jesus Children's University Hospital. As a control group, another 5 children with no pathology were evaluated. RESULTS: Obtained data shows significant differences between the two groups under study. Profile from individuals under AS shows deficit in linguistic as well as non verbal skills and, when compared to the control group, executive functions seem to be generally more altered. CONCLUSIONS: Further investigation is suggested to determine that the NVLS could be an explanation model for AS. On the other hand, we stress the need to deepen the study of the executive functions and their relationship with the mind's theory, as an hypothesis to explain the AS.

Radioimmunotherapy for non-Hodgkin's lymphoma; positioning, safety, and efficacy of 90Y-Ibritumomab. 10 years of experience and follow-up. / Radioinmunoterapia en el linfoma no Hodgkin, posicionamiento, seguridad y eficacia de 90Y-ibritumomab. Experiencia y seguimiento a los 10 años.

INTRODUCTION: Radioimmunotherapy (RIT) is one of the therapies directed against molecular targets in non-Hodgkin's lymphoma (NHL). OBJECTIVE: To evaluate the positioning, safety, and effectiveness of RIT with 90Y-Ibritumomab in NHL patients. METHOD: A retrospective study was conducted on patients with NHL who received RIT with 90Y-Ibritumomab. An evaluation was made of the concordance with clinical guidelines, toxicity as rated by the Common Terminology Criteria for Adverse Events (CTCAE), and effectiveness was assessed based on response to treatment, overall survival (OS), and progression-free survival (PFS). RESULTS: RIT was requested in 26 patients, of whom 21 (11 women, mean age 56±10 years) were included in the study, with the following distribution: Follicular NHL, 67%, Mantle NHL, 14%, Diffuse large B-cell NHL, 9.5%, and Transformed NHL 9.5%. Twelve patients with refractory NHL, 7 for consolidation response, and 2 transplant conditioning, were treated. Adverse effects were observed in 71% of patients, which were usually manageable and transient, and with the most common being thrombocytopenia. At 3-4 months, overall response rate was 76.2% (71.4% complete and 4.8% partial response), and 19% had progression of disease. With a median follow up of 70 months, the OS was 96±8 months, and the PFS was 54±11 months. CONCLUSION: RIT showed a moderate correlation with clinical guidelines, and is probably underused. Adverse effects were common, mild, and manageable. The data show a high complete response rate and an increase in the OS and PFS.

Thermoregulation in endothermic dung beetles (Coleoptera: Scarabaeidae): effect of body size and ecophysiological constraints in flight.

We explore the physiological constraints of body temperature as related to body mass and ambient temperature during flight in endothermic dung beetles showing a mass-related breakpoint where species show strong vs. weak endothermy. We found two different strategies in the dung beetles prior to flight; larger beetles (>1.9 g) elevate and maintain their body temperature (T(b)) at levels well above ambient temperature (T(a)) whereas smaller beetles' (<1.9 g) T(b) tends to conform with T(a). Physiological constraints analysis revealed a constant maximum tolerated temperature (in flight) of 42 degrees C and a minimum temperature for flight of around 25 degrees C. These, with body mass, may play a role in thermal niche partitioning and geographical distribution patterns.

Independent regulation of adherens and tight junctions by tyrosine phosphorylation in Caco-2 cells.

To study the role of tyrosine phosphorylation in the control of intercellular adhesion of intestinal cells, we have generated several clones of Caco-2 cells that express high levels of pp60v-src only after addition of butyrate. Expression of this oncogene in cells 5 days after confluence induced beta-catenin and p120-ctn tyrosine phosphorylation, redistribution of E-cadherin to the cytosol and disassembly of adherens junctions. However, tight junctions of Caco-2 cells at 5 days after confluence were not altered by expression of pp60v-src. Similar results were obtained when Caco-2 cells were incubated with phosphotyrosine phosphatase inhibitor orthovanadate. Although addition of this compound to postconfluent cells disrupt adherens junctions, tight junctions remain unaltered, as determined measuring monolayer permeability to mannitol or hyperphosphorylation of Triton-insoluble occludin. Modifications in tight junction permeability of Caco-2 were only observed at high concentrations of orthovanadate (1 mM). Interestingly, this tyrosine phosphorylation-refractory state was achieved after confluence since early postconfluent cells (day 2) showed a limited but significant response to low doses of orthovanadate. These results suggest that tight junctions of differentiated Caco-2 cells are uncoupled from adherens junctions and are insensitive to regulation by tyrosine phosphorylation.

[Study of renal function and compensatory changes in children with single kidney]. / Determinación de función renal y cambios compensadores en niños con riñón único.

INTRODUCTION: It has always been thought that a reduction of renal tissue in childhood sometimes causes some irreversible injury in the remnant kidney as the years go by. The aim of this paper is to look over the presence of these changes and identify the risk of nephropaty throughout several parameters. MATERIAL AND METHODS: We reviewed 38 children, 23 males and 15 females, aged between 1 and 15 years, who had lost unilateral renal mass because of congenital or adquired diseases. We made two groups of patients on the basis of having born without any unilateral renal function -group I- or having lost unilateral renal function after the second year of life. We measured: Somatometry, arterial pressure, glomerular filtration, microalbuminuria, renal volume and gammagraphic studies were also made. We also considered the presence of contralateral anomalies. RESULTS: Body weight and height were within normal percentiles. Arterial pressure increased in 5 patients. Seric creatinine was normal, creatinine clearance (Ccr) was higher than normal in all patients of both groups, and urinary excretion of protein was normal. Renal volume of remnant kidney was similar in both groups, and no relation with renal function level was found, but it increased through the years. Isotopic studies showed ectatic drainage in all urinary systems. Contralateral anomalies were seen in 7 patients, and they consisted in hydronephrosis and vesico-ureteral reflux. CONCLUSIONS: Hypertension was not related to the cause of renal absence nor the pathology of remnant kidney. Ccr was higher than normal, showing an hyperfiltration status, not confirmed by the values of isotopic filtrate. Renal volume reached by the single kidney was affected by the time after the renal loss, and apparently has been slowed down in cases with contralateral anomalies.

Chylothorax in cirrhosis of the liver: analysis of its frequency and clinical characteristics.

OBJECTIVES: To ascertain the frequency and to describe the clinical and biochemical features of cirrhotic chylothorax. DESIGN: A descriptive clinical study. SETTING: A community teaching hospital. PATIENTS AND METHODS: Since November 1989 to October 1995, 809 patients with pleural effusions were studied by thoracentesis. Pleural effusions with a concentration of triglycerides higher than 110 mg/dL, a pleural fluid to serum triglyceride ratio higher than 1, and a pleural fluid to serum cholesterol ratio lower than 1 were considered chylothorax. RESULTS: Twenty-four patients had pleural effusions that complied with all three aforementioned biochemical conditions. Five of these 24 patients (20%), were found to have liver cirrhosis as the main cause of chylothorax and in 3 of them, an abdominal source of the effusion could be demonstrated by intraperitoneal injection of a radioisotope (99mTc-sulfur colloid). The cirrhotic chylous effusions had significantly lower (p<0.005) protein (median, 1.7; range, 1.4 to 2.7 g/dL), lactate dehydrogenase (LDH) (median, 96; range, 77 to 138 IU/L), and cholesterol (median, 25; range, 22 to 64 mg/dL) levels than chylous effusions resulting from other causes (protein: median, 4.1; range, 1.7 to 6.8 g/dL; LDH: median, 351; range, 140 to 8,600 IU/L; and cholesterol: median, 87; range, 38 to 160 mg/dL). Cirrhotic chylothorax was always a transudate according to Light's criteria. CONCLUSIONS: Chylothorax is a rare and apparently underappreciated manifestation of cirrhosis resulting from transdiaphragmatic passage of chylous ascites. Its uniform biochemical characteristics can facilitate its separation from chylous effusions of different etiology, therefore avoiding potentially harmful diagnostic and therapeutic procedures.

Observation of the continuous stern-gerlach effect on an electron bound in an atomic Ion

We report on the first observation of the continuous Stern-Gerlach effect on an electron bound in an atomic ion. The measurement was performed on a single hydrogenlike ion ( 12C5+) in a Penning trap. The measured g factor of the bound electron, g = 2.001 042(2), is in excellent agreement with the theoretical value, confirming the relativistic correction at a level of 0.1%. This proves the possibility of g-factor determinations on atomic ions to high precision by using the continuous Stern-Gerlach effect. The result demonstrates the feasibility of conducting experiments on single heavy highly charged ions to test quantum electrodynamics in the strong electric field of the nucleus.

Morphology of a dicephalic cat.

A detailed anatomical study of a dicephalic iniodymic monosomic cat in conjunction with the morphogenetical implications of the observed anomalies is presented. The animal exhibited two heads joined at the level of an anomalous medial exoccipital bone. Two brains and two foramina magna were present. The vertebral column was single but the cranial cervical vertebrae (C2 to C5) had doubled bodies. Cervical rachischisis with myeloschisis were associated defects. Two nasopharyngeal and oropharyngeal cavities converged caudally into a single laryngopharynx. The esophagus, larynx and trachea were single. Duplication of the tongue and hyoid apparatus was present. Palatoschisis affected both oral cavities. Hypoplasia of the anatomical structures in the medial aspects of both heads was observed. Microphthalmia was also observed in both medial eyes. Comparative aspects of the morphology, causative agents, and mechanisms and anomalous morphogenesis of anterior duplications are reviewed and discussed.

Can a decision tree help nurses to grade and treat pressure ulcers?

OBJECTIVE: This study investigated whether a decision tree can aid pressure ulcer management. It hypothesised that nurses who use a decision tree in pressure ulcer care assess wound grade more accurately and select more appropriate dressings. METHOD: Sixty-six nurses were randomly assigned to two groups. Each nurse reviewed written information and pictures of three cases of pressure ulceration, and then graded and selected a dressing for the lesions. The absence or presence of a decision tree was used as an independent variable. Measurements included: mean and standard deviation; confidence intervals; percentages; Chi-square test, Pearson's correlation and Kruskal-Wallis test. RESULTS: Baseline characteristics were comparable for both groups. There was no statically significant difference between the grades selected by the two groups. But significantly more of the decision tree users selected an appropriate dressing (p < 0.02). Joint scores (ranging from 0 to 6) were assigned for each accurate decision. The mean score for the experimental group was 4.47 +/- 1.14 (95% CI: 0.95 [4.06-4.88]) and for the control group, 3.35 +/- 1.30 (95% CI: 0.95 [2.90-3.81]). CONCLUSION: Decision trees could help nurses to make complex clinical decisions. Further studies undertaken in a clinical setting are needed.

[MIBI and parathyroid gland function in secondary hyperparathyroidism]. / MIBI y funcionalismo de las glándulas paratiroideas en el hiperparatiroidismo secundario.

The role of the double phase parathyroid scintigraphy with MIBI in the primary hyperparathyroidism has been well studied. The present work analyzes the benefit of this image technique in the diagnosis and therapeutic approach to uremia associated hyperparathyroidism. We studied 18 dialysis patients with clinical and analytical data of hyperparathyroidism. All of them were receiving treatment with i.v. vitamin D. We carried out two scintigraphic studies, the first under basal conditions (without changes in treatment) and the second one, a week later after the stimulation of the parathyroid gland through the cessation of the treatment with vitamin D and phosphorus binders, and the use of a low-calcium dialysate. In the basal study, fourteen patients had a positive uptake test in at least one of the four glands. These patients had significantly higher PTHi levels than those with a negative scintigraphic study. After the stimulation test, we found a statistically significative rise in PHTi (644 vs 979 p < 0.001) and phosphorus levels (5.8 vs 7.3; p < 0.01), a slight fall in calcium levels (p = NS) and a statistically significative increment in the score of scintigraphic captation (5.5 +/- 4.5 vs 6.8 +/- 5; p < 0.05). We found a statistically significative correlation between the PTHi level and the score of scintigraphic uptake, in the basal study (r = 0.6, p < 0.01) and after stimulation (r = 0.6, p < 0.01). The only variable associated with the scintigraphic uptake was PTHi, justifying 31.1% of the variance in the first study and 32.7% in the second. In conclusion, the MIBI scintigraphic is a useful exploration in the uremic patient with hyperparathyroidism, as it predicts the functional state of the parathyroid glands according to uptake intensity. The stimulation test could be useful in planning therapy, but some of its characteristics need to be established, such as the precise time to reach the maximum level of parathyroid stimulation.

[Familial outbreak of pneumonia by psittacosis]. / Brote familiar de neumonía por psitacosis.

A familial outbreak (4 cases) of pneumonia by psittacosis in Vall de Uxó (Castellón) during the month of April in 1990 is described. In addition to the epidemiologic, clinical and serologic (complement fixation) studies carried out a survey and serology of 11 healthy controls (neighbors, and employees from a bird shop) were performed. The serum of a parrot recently acquired by the patients (positive at 1/8) was analyzed. The habit of petting the animal was significantly associated with the disease. The patient's response to treatment was good. The titers of antibodies versus Chlamydia psittaci were higher than those of the controls examined and the established threshold for positivity (1/36). In addition to clinical intervention the roles of epidemiology and the participation of veterinary services are fundamental to control this disease the exact prevalence of which is unknown.

[Ulcerative colitis and colonic angiodysplasia associated with a lower digestive hemorrhage. Their diagnosis by 99-technetium-labelled red blood cells]. / Colitis ulcerosa y angiodisplasia de colon, asociadas en una hemorragia digestiva baja. Diagnóstico mediante hematíes marcados con 99mtecnecio.

We describe a case of a patient with previously diagnosed of ulcerative colitis, who was admitted to the hospital because of rectal bleeding and abdominal pain. A mild active colitis was reported by colonoscopy with biopsy. Rectal bleeding relapsed, and an arteriovenous malformation in the transverse colon compatible with angiodysplasia was located by early vascular scintigraphy with 99m-technetium-labeled red blood cells. This finding was confirmed by selective arteriography. Four months after hemicolectomy, the patient is free of rectal bleedings. Labeled red blood cell scintigraphy may be useful to differential diagnosis of lower digestive hemorrhage.

[Control of Chagas' disease in Guarani communities: knowledge and hygiene habits within the Project to Improve Living Conditions in Bolivia]. / Control del Chagas en comunidades guaraníes: conocimiento y hábitos higiénicos dentro del Proyecto de Mejoramiento de Viviendas en Bolivia.

The aim of this study was to identify knowledge and control of vectorial transmission (Triatoma infestans, known as vinchuca) of Chagas' disease in Guaraní Communities in Bolivia. We performed a descriptive study of a series of 98 individuals through a semi-structured questionnaire. Interviewees were asked about their familiarity with vinchuca, whether they thought vinchuca produced disease, the name of the disease and its consequences, as well as behavior related to eliminating the domestic insect vectors, such as cleaning of the home, backyard and corral.The insect vector was sufficiently well known (98%), although the name of the disease was identified by only 14.3% of the interviewees. Although the dwellings favored insect proliferation, they were not frequently cleaned: 28.6% cleaned their homes while and 42.9% cleaned the backyard and 7.1% cleaned the corral. Gender differences were found in the division of labor: women cleaned the homes and backyards, while men clean the corral. Experience has shown that the usefulness of projects for building healthy living areas and for health education depends on the value given to these projects by the community. Women are probably the best target group, because they perform a greater number of preventive tasks and seldom leave the community for extended periods of time.