Study of TiO2/Ti4O7 photo-anodes inserted in an activated carbon packed bed cathode: Towards the development of 3D-type photo-electro-Fenton reactors for water treatment.

In this work, commercially available Polymethyl-meta-acrylate (PMMA) spectroscopy cells were modified on the external walls with films of TiO2, Ti4O7 or TiO2/Ti4O7 mixtures. Film characterization was carried out using SEM and UV-vis spectroscopy. The results of photocatalytic (PC), electro-oxidation (EO), and photoelectrochemical (PEC) experiments on the decolorization of a methyl orange (MO) model dye solution showed that while anatase provides better photocatalytic properties and the partially reduced Ti4O7 larger electronic conductivity, the TiO2/Ti4O7 composite film behaves as a semiconductor substrate that combines the advantages of both materials (for PEC experiments for instance, decolorization values for the model dye solution using TiO2, Ti4O7 and a TiO2/Ti4O7 mixed film, corresponded to 35%, 46% and 53%, respectively). In order to test this film as an effective photoanode material in a 3-D type reactor for water treatment processes, a TiO2/Ti4O7 modified PMMA spectroscopy cell was inserted in an activated carbon (AC) bed so that the semiconductor material could be illuminated using an external UV source positioned inside the PMMA cell. The connected AC particles that were previously saturated with MO dye were used as cathode sites for the oxygen reduction reaction so that the photoelectrochemical reactions that take place in the anode could be complemented with coupled electro-Fenton processes in the cathode. As expected, the combination resulted in an effective decolorization of the dye solution that results from a complex combination of processes. The experimental decolorization data was successfully fitted to a pseudo-first order kinetic model so that a deeper understanding of the contribution of each process in the reactor could be obtained.

Effect of enzymatic pretreatment on the physical quality of plantain (Musa ssp., group AAB) employing airflow reversal drying.

This work aimed to evaluate the effect of enzymatic pretreatment on the color and texture of plantain (Musa ssp., group AAB) dried by airflow reversal drying. Plantain slices 1.0 cm thick were used. Pretreatment with two commercial enzymes, Pectinex Ultra SPL (Aspergillus aculeatus) and Pectinex 3XL (Aspergillus niger), was performed. Drying kinetics were determined with and without pretreatment at temperatures of 50, 65 and 80 °C using a fixed bed convective dryer. An air speed of 6 m/s, a bed height of 5 cm and either unidirectional flow or airflow reversal (every 15 min) were used for drying. Color and texture were analyzed, and consumer acceptance of the results of the best treatments was determined. Pretreatment with the enzyme A. niger and airflow reversal gave the best drying kinetics and showed the greatest reduction in drying time (59.0%) at 80 °C. The best hardness results were found at 80 °C with A. niger enzymatic pretreatment with both types of air flow. Brightness and hue angle showed that samples pretreated with enzymes and dried at 65 °C had a lighter yellow color compared to non-pretreated samples. Plantain samples enzymatically pretreated and dried at 65 and 80 °C were the most accepted by consumers. This kind of enzymatic pretreatment on plantain could allow the conservation of some physical properties and reduction of drying times relative to the current methodology.

Preparation of betulinic acid nanoemulsions stabilized by ω-3 enriched phosphatidylcholine.

Bioactive compounds such as ω-3 fatty acids and terpenes, have been associated with beneficial health effects; however, their solubility in the gastrointestinal tract and its bioavailability in the body are low. Nanoemulsions offer a viable alternative to disperse lipophilic compounds and improve their dissolution, permeation, absorption and bioavailability. Enzyme modified phosphatidylcholine (PC) with ω-3 fatty acids was used as emulsifier to stabilize oil-in-water nanoemulsions generated using ultrasound device. These systems were used as carriers of betulinic acid, which has reported anti-carcinogenic activity. Phospholipase-catalyzed modification of PC allowed the incorporation of 50 mol% of ω-3 fatty acids. Formation variables such as oil type and ultrasound amplitude had effects on nanoemulsion characteristics. Incorporation of betulinic acid affected globule size; however, betulinic acid nanoemulsions below 200 nm could be prepared. The conditions under which betulinic acid nanoemulsions were obtained using the modified phosphatidylcholine with the smaller globule size (91 nm) were 10% PC, 25% glycerol, medium chain oil and 30% amplitude for 12 min in the sonicator. Storage temperature had an effect on the stability of the nanoemulsions, at 5°C we observed the smallest growth in globule size. The use of olive oil decreased the globule size growth during storage of the nanoemulsion stabilized with modified phosphatidylcholine, although globule size obtained was greater than 200 nm. Medium pH had a significant effect on the nanoemulsions; alkaline pH values improved storage stability. These results provide useful information for using this type of carrier system on the formulation of products in the pharmaceutical or food industry.

Network efficient power control for wireless communication systems.

We introduce a two-loop power control that allows an efficient use of the overall power resources for commercial wireless networks based on cross-layer optimization. This approach maximizes the network's utility in the outer-loop as a function of the averaged signal to interference-plus-noise ratio (SINR) by considering adaptively the changes in the network characteristics. For this purpose, the concavity property of the utility function was verified with respect to the SINR, and an iterative search was proposed with guaranteed convergence. In addition, the outer-loop is in charge of selecting the detector that minimizes the overall power consumption (transmission and detection). Next the inner-loop implements a feedback power control in order to achieve the optimal SINR in the transmissions despite channel variations and roundtrip delays. In our proposal, the utility maximization process and detector selection and feedback power control are decoupled problems, and as a result, these strategies are implemented at two different time scales in the two-loop framework. Simulation results show that substantial utility gains may be achieved by improving the power management in the wireless network.

[Pharmacologic reperfusion in acute myocardial infarction]. / Reperfusión farmacológica en el infarto agudo del miocardio.

Reperfusion therapy is fundamental in the treatment of the acute myocardial infarct and can be accomplished either through pharmacological methods or through direct angioplasty. Undoubtedly, pharmacological reperfusion is the most available and it has modified the natural history of the acute myocardial infarct. Reperfusion therapy must be as dynamic and multifactorial as the physiopathology per se of the acute myocardial infarct. Reperfusion is defined as: to reestablish blood flow after an obstruction has been caused and to be useful it must be close to normal both in the epicardial and transmyocardial vessels.

[Influence of the pericardium in the pathophysiology of ventricular dysfunction in acute infarct of the right ventricle. Experimental study] . / La influencia del pericardio en la patofisiología de la disfunción ventricular en el infarto agudo del ventrículo derecho. Estudio experimental.

UNLABELLED: To obtain more information about the role of the pericardium in the setting of acute right ventricular infarction (ARVI) we studied the behaviour of the ventricular function curves (VFC) and the relationship of the ventricular end-diastolic pressures (R-VEDP-RV:LV) in two groups of dogs. Group A. (n = 12) Control (C), ARVI, Pericardiectomy (P). A parabolic behaviour of the C VFC was noted (r2 = 071) and it's flexion point (FP) was found in 13. +/- 2 mmHg. After the ARVI the right (R) VFC was shifted downwards and to the right and the FP was documented in 18 +/- 2 mmHg (p < 0.05) in relation to C VFC. After P the RVFC was displaced upwards and to the left in relation to ARVIC RVFC (p < 0.05). The C R-VEDP-RV:LV = 0.75 and only a trend to equalization after the ARVI and after P were noted (0.91, 0.84, respectively) (p = ns). Group B (n = 12). Control (C), P, ARVI. The RVFC after P was shifted up and to the left in relation to the C RVFC (p < 0.05) and the FP = 10 +/- 2 mmHg. After P in the setting of ARVI the RVFC was shifted downward and to the right in relation to P RVFC (p < 0.05). After P the R-VEDP-RV:LV = 0.45 and statistical significant equalized in the condition of ARVI without pericardium (0.95, p < 0.05). CONCLUSION: Ours results support a partial restrictive role of the pericardium in the origin of the low cardiac output (LCO) in ARVI. Because, equalization of the R-VEDP-RV:LV is not only due to the restraining pericardial effect but is also due to right ventricular myocardial ischemia. The FP (18. +/- 2 mmHg) found seems to be the top value of RVEDP for volume infusion in experimental ARVI. Hemodynamic finding that could be useful in the preload volume management for humans with ARVI and LCO or systemic hypotension.

[Ventricular function curves with and without pericardium: analysis of pericardial pressures]. / Las curvas de función ventricular con y sin pericardio: análisis de las presiones pericárdicas.

Simultaneous right and left ventricular function curves (VFC, R, L) were obtained in a canine model, (open chest preparation), with and without pericardium. Preload and afterload conditions for the right and left ventricles were controlled. VFC were constructed from zero to 25 mmHg of ventricular end-diastolic pressures and by increasing the cardiac output from 50 to 250 mL/kg-1min-1. Both, right and left VFC showed an initial steep rise at low filling pressures and then flattened off to a plateau at high filling pressures. The best mathematical model that fitted with the VFC, with and without the pericardium was the parabola (r2 = 0.71, 0.72 respectively). After pericardiectomy R and L VFC were displaced to the left of the VFC with pericardium and a decrease in filling pressures were noted at the same points of cardiac output, findings that suggest a restraining effect of the pericardium. By subtracting the filling pressures obtained with pericardium from those without pericardium at the same levels of cardiac output, pericardial pressures were derived. In all the range of the VFC the pericardial pressures were positive, and this pressure increase as cardiac output increase. Thus the transmural pressure was never cero, for both right and left ventricles. The observed relation for the R and L filling pressures, derived from a polynomial equation of second order suggest a small although not unimportant effect of the pericardium at normal filling pressures, and a very substantial influence at high levels of cardiac output. The demarcation between small and major effects appears in the upper range of normal filling pressures in this dynamic approach of the pericardial pressures.

[Comparative analysis of reperfusion time in primary angioplasty vs thrombolysis. Success vs time]. / Análisis del tiempo de reperfusión entre angioplastía primaria y trombolisis: éxito vs tiempo.

UNLABELLED: We studied 398 patients with diagnosis of acute myocardial infarction who arrived within the first six hours of symptom onset that were treated with thrombolysis or primary angioplasty, they were divided in two groups: Group 1 (n = 198), those treated with 1.5 million U of streptokinase over 60 min and Group 2 (n = 200), those treated with primary angioplasty. In Group 1 the "pain-door" time was 3.7 +/- 1.7 hs vs 3.8 +/- 2.4 hs in group 2 (p = NS). The "door-needle" time was 48 +/- 12 min. compared with the "door-balloon" time of 84 +/- 30 min (p < 0.001). In Group 1, 154 (77.6%) of the patients had clinical of reperfusion after thrombolysis, 58 of them underwent coronary angiography and had an infarct related artery (IRA) patency rate of 45.3%. In Group 2 the IRA patency rate was 85.5% (p < 0.005). CONCLUSION: Thrombolysis was achieved in a lesser period of time but our findings showed that primary angioplasty was more effective obtaining a TIMI 3 flow.

[The utility of rapid qualitative determination of troponin T, the MB fraction of creatine phosphokinase and myoglobin in acute ischemic coronary syndromes]. / Utilidad de la determinación cualitativa rápida de troponina-T, fracción MB de creatina fosfocinasa y mioglobina en los síndromes isquémicos coronarios agudos.

The objective of our study was to validate the diagnostic utility of cardiac troponine T in acute ischemic syndromes, and also in cases of difficult diagnosis. We analyzed its concordance and compare them with conventional enzymatic quantitative methods. We determined sensitivity, specificity, positive and negative predictive values and likelihood ratio. Kappa index was used to know the concordance grade between T troponin and the positive or negative results of the quantitative enzymatic curve. Stochastic significance was valued by Chi square of Mcnemar test. In seventy patients who arrived to the hospital with chest pain who were assigned to five different groups. The sensitivity in quantitative markers was higher than qualitative methods, however the specificity, likelihood ratio was lower. In the total group the concordance analysis between qualitative and quantitative markers was adequate, (kappa index 0.65 p < 0.05). This study suggest that the rapid bedside qualitative test by cardiac Troponin T is a good diagnostic marker compared with conventional quantitative markers to evaluate chest pain in acute ischemic syndromes.

[Late thrombolysis and electrical stability in acute myocardial infarction. Role of the collateral flow]. / Trombolisis tardía y estabilidad eléctrica en el infarto agudo del miocardio: importancia del flujo colateral.

We evaluated 249 patients (pts) with first acute myocardial infarction: 1. Pts without thrombolysis, n = 119, 2. Pts treated with thrombolysis within 6 hours following MI, n = 80 and 3. Pts treated with thrombolysis between 6-12 hours after MI. Arrhythmic events were evaluated during follow up. All underwent heart rate variability studies and coronary angiogram where anterograde flow (TIMI) and collateral flow (Rentrop scale 0-2 = poor collateral flow and 3 = good collateral flow) were determined. Pts in group 2 and 3 showed a better anterograde and collateral flow than group 1 (p < 0.001). A lower spectral power in the high frequency band and a higher ratio low/high frequency band were observed in group 1 (p < 0.05). Conjunctive consolidation analysis showed more malignant arrhythmias in TIMI 0-2 with poor collateral flow than TIMI 0-2 with good collateral flow (17/138-12.3% vs 0/14-0%). Kaplan Meier analysis was able to demonstrate more cardiac sudden death events in TIMI 0-2 with poor collateral flow than TIMI 0-2 with good collateral flow or TIMI 3 (x2 = 7.22, p = 0.028), independently of thrombolytic treatment.

[Results of treatment of acute myocardial infarction with thrombolytic therapy. Experiences in 437 patients in the coronary care unit of the National Institute of Cardiology "Ignacio Chavez"]. / Resultados del enfermo con infarto agudo del miocardio con terapia trombolítica. Experiencia en 473 enfermos de la unidad coronaria del instituto nacional de cardiología ignacio chávez.

OBJECTIVE: To review the results and complications of thrombolysis in patients with acute myocardial infarction (AMI) and its complications. METHODS: Since june 1989 to august 1994 we studied patients with AMI, who underwent thrombolysis. Clinical characteristics, complications and angiographic results are described. RESULTS: Of the total population 86.3% patients received Streptokinase (SK) and 13.7% recombinant tissue plasminogen activator (rt-PA). In 20 patients the age was under 40 years, 373 between 40-70 years, and 80 patients over 70 years. 84% were men and 16% women. 72% had smoking habit; 21% diabetes mellitus, 43% hypertension, 54% had previous angina and previous AMI in 22%. The location of AMI was anterior in 234 patients and 239 inferior. In 63% enzyme washout was observed, and rapid electrocardiographic evolution in 81%. Postthrombolisis arrhythmias was observed in 64.7%. Major bleeding in 11.8% and central nervous system hemorrhage in 0.4% only with rt-PA. Postinfarction angina in 22%, and re-infarction in 4%. Cardiac rupture in 1.4%, with shock and death. Mitral insufficiency in 2.1% demonstrated by echocardiogram. Coronary angiography was done in 373 patients (80%), of which 50.7% was made in the first 5 days. The culprit artery was anterior descending in 273 patients and right coronary in 95. Left ventricular dysfunction was seen in 23% in patients with anterior AMI, and 5% with inferior AMI. Cardiogenic shock was seen in 7%. Coronary artery bypass grafting was undertaken in 106 patients and coronary angioplasty in 67. The ten days mortality was 8.8%, principally due to cardiogenic shock, ventricular arrhythmias and ventricular rupture. CONCLUSIONS: The usefull permeability in the culprit artery was obtained in 40%, who had coronary angiography done 145 hours posthrombolysis. Mortality was under 10% in this study.

[Myths, prejudices and reality about dental treatment during pregnancy. A medical opinion]. / Mitos, prejuicios y realidades del tratamiento odontológico durante el embarazo. Opinión médica.

The education and assistance strategies aimed al preserving oral health must play an important role in the overall care of the pregnant woman. It has been demonstrated that there are beliefs and practices in our culture that relegate, odontologic care in this stage, where attitudes and behaviors on the health-disease process are influenced by the prevailing medical culture, which includes the physician's opinion. The objective was To obtain the physician's opinion on the odontologic care during pregnancy. A previously validate survey which included 15 questions, was applied to a randomly selected sample of 700 physicians. Of the 650 surveys analyzed, 57% were applied to general practitioners, 24% to gynecologists and obstetrician, and 19% to other medical specialist regularly consulted by women during their prenatal care. There is low referral of pregnant women to the regularly check their patients teeth of gums 53% physicians said that the odontologist did not need to consult them about dental treatment, while 593 thought otherwise, 362 surveyed practitioners point out the convenience of using the lead apron when taking periapical x-ray. These results point out the importance of establishing a good communication channel between the physician and dentist. It is clear that there is a lack of truth in the oral health specialist's ability to provide treatment to pregnant patients, and that the physician ignores many of the odontological procedures and their low risk.

[Analysis of reperfusion by thrombolysis of the artery responsible for acute myocardial infarction]. / Análisis de la permeabilidad por trombolisis de la arteria responsable de infarto miocárdico agudo.

OBJECTIVE: To analyze the role of the culprit coronary artery in myocardial infarction, its evolution and mortality. And to correlate with clinical criteria of reperfussion. MATERIALS AND METHODS: We included patients with clinical diagnosis of acute myocardial infarction (MI) treated with thrombolytic therapy, and coronariography. We used the TIMI study angiographic scale to evaluate the level of permeability of the culprit artery. RESULTS: Of 473 patients with of acute MI; coronariography was made in 377. The most frequent culprit vessel was anterior descending artery in 168 patients (45%) and right coronary artery in 139 patients (36%). In 276 patients the culprit vessel was permeable (73%). Of them in 30 patients, had TIMI 1 alterations, TIMI 2 in 97 patients, had TIMI 3 in 148 patients, only 102 patients had TIMI 0. In anterior MI the most frequent reperfussion arrhythmia was ventricular ectopic beats followed by slow ventricular tachycardia and ventricular tachycardia in 54%, ventricular fibrillation was observed only in six patients, of whom TIMI scale was 2 and 3 in five patients. In inferior MI, ventricular ectopic beats and slow ventricular tachycardia was seen in 25% of patients. In patients with permeable culprit artery we observed significant depression of ST segment, (159 patients, 42%), and significant increase in CK-MB levels, seen in 191 patients (51%). In the group of patients with total occlusion of the culprit artery, twenty-one (30%) had left ventricular disfuntion, and only six of them were in cardiogenic shock. In the group of patients with permeable culprit artery only two percent had cardiogenic shock. Therefore the analysis of the clinical evolution is the maia marker to take into consideration to send patients to early coronary arteriography with the objective to look for other therapeutic alternatives.

[Treatment of acute myocardial infarction with rt-PA in 60 minutes. Cooperative study]. / Tratamiento del infarto agudo del miocardio con rt-PA en 60 minutos. Estudio cooperativo.

UNLABELLED: Thrombolytic therapy (TT) modifies the natural history of acute myocardial infarction (AMI) diminishing morbi-mortality rate. In recent studies, modification of infusion velocity, decreased the mortality 10 percentage points. OBJECTIVE: Test if rt PA administration over an hour is safe and practical. MATERIAL AND METHODS: A prospective, cooperative trial during 3 years, included patients with AMI with less than 6 hours of the onset of symptoms that received rt-PA therapy. Initially 10 mg bolus and then 90 mg over 60 minutes period. Together with the administration of rt-PA, 5000 units of heparin was given, followed by 1000 units per hour adjusted to keep PTT at 1.5 to 2 times normal. All patients received aspirin and according of the evolution adjuvant therapy. We defined bleeding complications and/or cerebrovascular accident related to thrombolytic therapy. RESULTS: We included 225 patients who received rt-PA. Average age was 57.1 +/- 22.2 years, 78.7% males and 21.3% females. Arrival time at hospital was 2.93 +/- 1.7 hours. 82.2% were in class I-II by NYHA. 59.2% had anterior wall location and 32.4% posterior-inferior wall 80% had reperfusion criteria. Only 7.1% required transfusion and 0.4% presented CNS bleeding. The survival rate was 95.2%. The mortality had no relation with bleeding. CONCLUSION: Fast infusion is an effective and safe method. Transfusion requirements are no greater, and CNS bleeding was noted in 0.4% of the cases.

[Hemodynamic effects of oral captopril in patients with critical aortic stenosis]. / Efectos hemodinámicos del captopril oral en pacientes con estenosis aórtica crítica.

OBJECTIVES: To analyse the hemodynamic and ventricular function effects of oral captopril in severe aortic stenosis. PATIENT POPULATION: inclusion criteria: patients older than 18 years with critical aortic stenosis. EXCLUSION CRITERIA: angiotensin-converting enzyme inhibitor used previously contraindication to right catheterisation aortic insufficiency, valvular prosthesis in aortic position, or other valvulopathy. As well as the need for immediate valvular aortic replacement arrhythmia, A-V conduction alterations, or ventilatory support. PROTOCOL: prospective, no randomized. Swan-Ganz catheter was used. Basal hemodynamic measurements were made on 1, 2, 4, 6 and 8 hours during 48 hours. Captopril was administered 12.5 mg first and then 8 mg tid (6 doses). STATISTICAL ANALYSIS: Neuman-Keuls test was used for multivariate comparisons. Statistical significance was determined with P < 0.05. RESULTS: 22 patients were analyzed. Systemic vascular resistance fell from 1750 Dyn/seg/cm-5 to 1200 (P-0.001), cardiac output increased from 4.1l/min to 5.8 (P-0.001), cardiac index increased from 2.4 l/min/m2 to 2.9 (P-0.009), stroke volume from 47 ml to 64 (P-0.04) and stroke volume index from 27 ml/m2 to 36 (P-0.002). In patients with heart failure (n = 7) the systemic vascular resistance fell from 2050 Dyn/seg/cm-5 to 1463 (P-0.04), cardiac output increased from 2.8l/min to 4.1 (P-0.04), cardiac index from 2.07 l/min/m2 to 2.75 (P-0.04), stroke volume from 46 ml to 64 (P-0.03), pulmonary capillary wedge pressure fell from 19 mmHg to 16 (0.04) and the systolic pulmonary arterial pressure fell from 63 mmHg to 42 (P-0.009). CONCLUSIONS: captopril improves the hemodynamic parameters in patients with critical aortic stenosis, principally in those with heart failure.

[Acute myocardial infarction related to cocaine use. Report of a case]. / Infarto agudo del miocardio relacionado con el consumo de cocaína. Informe de un caso.

Cocaine use has been associated with ischemic syndromes, especially angor pectoris, myocardial infarction, cardiac arrhythmias and sudden death. A significant number of persons suffering from myocardial infarction associated with cocaine abuse do not have significant coronary atherosclerosis, and the mechanism for infarction in these patients have remained obscure. This report describes a young man with angiographically normal coronary arteries in whom cocaine abuse probably produced coronary artery spasm leading to coronary thrombosis and infarction.

[Attitudes and behavior for reproductive health]. / Actitudes y conductas para la salud reproductiva.

Educational interventions represent an alternative for the reproductive well-being. The objective of this investigation was to identify in a mexican community, attitudes and behaviors related to reproductive health, with the goal of implementing a specific health education program. The study population consisted of women between 12 and 44 years old, living in non-residential areas of the Delegation Miguel Hidalgo, D.F. Variables of interest were analyzed only in women with parity (n = 300). Data were collected through interview. The mean age was 31 +/- 8 years. 93.3% were married or in consensual union. 63% had elementary, junior high or prevocational studies. 89% answered that would visit the doctor before considering a pregnancy (junior high+, p < .05), 99% would seek prenatal care if they were pregnant, and 92.7% would have a hospital delivery (parity < or = 3, p < .003). 69.5% had a preconceptional visit before their last pregnancy and 89.9% received prenatal care (junior high+, p < .008). 92.5% had only hospital deliveries (< or = 30 years, p < .05, junior high+, p < .0001, primigravida p < .002, with institutionalized medical services, p < .001), 1.7% had only out-of-hospital deliveries, and 5.8% both. Agreement between attitudes and behaviors are presented. An educational program consisting of confirmation and support to positive attitudes, values and beliefs, and reinforcement to decision making, will result in a final behavior: early assistance to medical care.

[Perception of reproductive risk factors]. / Percepción de factores de riesgo reproductivo.

The objective of this study was to identify risk perception on several factors related to reproductive health, with the goal of implementing an educational intervention based on detected needs. 405 women between 12 and 44 years were interviewed at home. 62.2% perceived the risk of pregnancy at 17 years and younger; 78.8% the risk of pregnancy at 35 years and older; 76.6% the risk of parity of 5 and higher; and 55.1% the risk of birth interval of 2 years and less. 60.5% recognized family history of birth defects, 80.2% age 35 years and older, and 84.4% rubella during pregnancy, as risk factors for newborns with congenital malformations. 27.7% identified history of a low birth weight and 61.0% birth interval of 1 year and less, as risk factors for low birth weight. The majority perceived the risk of tobacco, alcohol and drugs consumption during pregnancy, diseases with no treatment and deficient nutrition. There was an inconsistent influence of social and obstetric variables on risk perception. No linear correlation was detected. Health educators should recognize differences on knowledge and behavior of future receptors before an educational intervention starts.

PIP: 405 lower class women aged 12-44 in the Delegacion Miguel Hidalgo, Mexico City, were interviewed in their homes in an effort to identify patterns in their perceptions of reproductive risk factors. The women were interviewed in late 1989 with a largely precoded questionnaire containing items described in the literature as risk factors for pregnancy, low birth weight, and birth defects. 7.9% of the respondents were 12-15 years old, 17.3% were 16-20, 37.0% were 21-30, 24.4% were 31-40, and 13.3% were 41-44. 24.9% were single, 59.5% were married, and 12.0% were in free union. 7.9% had no education, 33.8% had primary, 33.8% secondary, 20.9% preparatory, and 3.5% professional educations. Among the 300 women who had children, 23.6% had 1, 48.9% had 2-3, and 28.3% had 4 or more. 22.7% had histories of abortion, 1.3% of stillbirths, 15.7% of premature labor, 11.3% of low birth weight infants, 4.7% of neonatal deaths, and 5.0% of infant death. 62.2% perceived the risk of pregnancy at 17 years or younger, 78.8% the risk of pregnancy at age 35 or over, 70.6% the risk of a 5th or higher order pregnancy, and 55.1% the risk of a birth interval of less than 2 years. The majority perceived smoking, drinking alcohol, untreated pathologies during pregnancy, and inadequate nutrition to be risk factors. 27.7% identified a history of low birth weight infants and 61.0% birth intervals of 1 year or less as risk factors for low birth weight. 60.5% recognized family history of birth defects, 80.2% maternal age of 35 or over, and 84.4% rubella during pregnancy as risk factors for congenital malformations. The influence of sociodemographic and obstetric variables on perception of risks was inconsistent and no linear correlations were detected. Health educators should recognize differences in levels of knowledge and behavior in the target population when the educational program is designed.

[Nosocomial infection in the neonatal period at a third level care center]. / Infección nosocomial en la etapa neonatal en un centro de tercer nivel de atención.

Results are presented on epidemiologic surveillance of nosocomial infection of all neonates attended at the Instituto Nacional de Perinatologia throughout 1988-1990, reporting rates of 2.1, 2.9 and 5.5 per 100 discharge for each of the years studied. Data are presented in full by service, showing rates of 4.7, 9.5 and 23.0 per 100 discharge in Neonatal Intensive Care Unit (NICU) and 1.5, 3.2 and 6.7 per 100 discharge for Neonatal Intermediate Care (NIC) for the same three years. With respect to type of infection, septicemia, pneumonia and conjunctivitis come as the most frequent causes of infection and Staphylococcus sp coagulase negative (30%), Staphylococcus aureus (27%) and Escherichia coli (7%) as the prevailing microorganisms in nosocomial infection.