Time-dependent analysis of extra length of stay and mortality due to ventilator-associated pneumonia in intensive-care units of ten limited-resources countries: findings of the International Nosocomial Infection Control Consortium (INICC).

Ventilator-associated pneumonias (VAPs) are a worldwide problem that significantly increases patient morbidity, mortality, and length of stay (LoS), and their effects should be estimated to account for the timing of infection. The purpose of the study was to estimate extra LoS and mortality in an intensive-care unit (ICU) due to a VAP in a cohort of 69,248 admissions followed for 283,069 days in ICUs from 10 countries. Data were arranged according to the multi-state format. Extra LoS and increased risk of death were estimated independently in each country, and their results were combined using a random-effects meta-analysis. VAP prolonged LoS by an average of 2·03 days (95% CI 1·52-2·54 days), and increased the risk of death by 14% (95% CI 2-27). The increased risk of death due to VAP was explained by confounding with patient morbidity.

Model of the meniscus of an ionic-liquid ion source.

A simple model of the transfer of charge and ion evaporation in the meniscus of an ionic-liquid ion source working in the purely ionic regime is proposed on the basis of order-of-magnitude estimates which show that, in this regime, (i) the flow in the meniscus is dominated by the viscosity of the liquid and is affected very little by the mass flux accompanying ion evaporation, and (ii) the effect of the space charge around the evaporating surface is negligible and the evaporation current is controlled by the finite electrical conductivity of the liquid. The model predicts that a stationary meniscus of a very polar liquid undergoing ion evaporation is nearly hydrostatic and can exist only below a certain value of the applied electric field, at which the meniscus attains its maximum elongation but stays smooth. The electric current vs applied electric field characteristic displays a frozen regime of negligible ion evaporation at low fields and a conduction-controlled regime at higher fields, with a sharp transition between the two regimes owing to the high sensitivity of the ion evaporation rate to the electric field. A simplified treatment of the flow in the capillary or liquid layer through which liquid is delivered to the meniscus shows that the size of the meniscus decreases and the maximum attainable current increases when the feeding pressure is decreased, and that appropriate combinations of feeding pressure and pressure drop may lead to high maximum currents.

Breakup of a supported drop of a viscous conducting liquid in a uniform electric field.

Numerical computations and order-of-magnitude estimates are used to describe the time evolution of a drop of a very viscous liquid of finite electrical conductivity attached to a metallic plate which is suddenly subject to a uniform electric field. Under the action of the electric stresses induced at its surface, the drop elongates in the direction of the field, and charged droplets are emitted when the strength of the field is higher than a certain critical value. A stationary emission mode exists in which the attached drop develops a conical tip and a thin jet, with small droplets emitted from the end of the jet in a process that involves the formation of a long ligament. The flow rate and the electric current carried by the stream of droplets emitted in this mode are determined by the flow and the transfer of charge in the attached drop, in particular in a small region around its tip and in a leading stretch of the jet, where the solution is nearly stationary despite the transient character of the jet further downstream. A simplified analysis of the stationary regions is carried out to elucidate the effects of the physical properties of the liquid (electrical conductivity, permittivity, viscosity, and surface tension), the volume of the drop, and the strength of the applied field. For high electrical conductivities and applied fields well above its critical value, the electrical and viscous stresses are large compared to surface tension stresses, and their balance gives a flow rate proportional to the square of the applied field. The electric current is then that of a stationary electrified jet fed with this flow rate.

Renal clear cell carcinoma metastasis to submandibular gland: case report and review of the literature.

Metastases from renal clear cell carcinoma (RCCC) to the head and neck (HN) region are rare, representing 8-14% of all RCCC metastases, with the thyroid gland being the most common site of RCCC metastasis in the HN. Metastatic tumors that are located in the salivary glands have a prevalence of 5%, while the submandibular gland is only involved in 1% of the cases. We present the case of a 74-year-old female patient with metastasis to the submandibular gland, 11 years after radical nephrectomy for a RCCC.

Natural convection in tilted cylindrical cavities embedded in rocks.

This paper presents a theoretical investigation of the low Rayleigh number conjugate natural convection in a slender tilted cylindrical cavity which is embedded in a solid that is subject to a uniform vertical temperature gradient. Two cases have been analyzed; a fluid-filled cavity and a cavity filled with a fluid-saturated porous medium. The temperature of the solid and the velocity, temperature, and pressure in the cavity have been determined by analytically solving the coupled problems within and around the cavity. The effect of the ratio of the thermal conductivity of the material in the cavity to the thermal conductivity of the solid on the structure of the convection flow is discussed. The theoretical results for convection in the fluid-filled cavity are shown to be in good agreement with experimental PIV measurements.

Periodic emission of droplets from an oscillating electrified meniscus of a low-viscosity, highly conductive liquid.

The generation of identical droplets of controllable size in the micrometer range is a problem of much interest owing to the numerous technological applications of such droplets. This work reports an investigation of the regime of periodic emission of droplets from an electrified oscillating meniscus of a liquid of low viscosity and high electrical conductivity attached to the end of a capillary tube, which may be used to produce droplets more than ten times smaller than the diameter of the tube. To attain this periodic microdripping regime, termed axial spray mode II by Juraschek and Röllgen [R. Juraschek and F. W. Röllgen, Int. J. Mass Spectrom. 177, 1 (1998)], liquid is continuously supplied through the tube at a given constant flow rate, while a dc voltage is applied between the tube and a nearby counter electrode. The resulting electric field induces a stress at the surface of the liquid that stretches the meniscus until, in certain ranges of voltage and flow rate, it develops a ligament that eventually detaches, forming a single droplet, in a process that repeats itself periodically. While it is being stretched, the ligament develops a conical tip that emits ultrafine droplets, but the total mass emitted is practically contained in the main droplet. In the parametrical domain studied, we find that the process depends on two main dimensionless parameters, the flow rate nondimensionalized with the diameter of the tube and the capillary time, q, and the electric Bond number B(E), which is a nondimensional measure of the square of the applied voltage. The meniscus oscillation frequency made nondimensional with the capillary time, f, is of order unity for very small flow rates and tends to decrease as the inverse of the square root of q for larger values of this parameter. The product of the meniscus mean volume times the oscillation frequency is nearly constant. The characteristic length and width of the liquid ligament immediately before its detachment approximately scale as powers of the flow rate and depend only weakly on the applied voltage. The diameter of the main droplets nondimensionalized with the diameter of the tube satisfies d(d)≈(6/π)(1/3)(q/f)(1/3), from mass conservation, while the electric charge of these droplets is about 1/4 of the Rayleigh charge. At the minimum flow rate compatible with the periodic regimen, the dimensionless diameter of the droplets is smaller than one-tenth, which presents a way to use electrohydrodynamic atomization to generate droplets of highly conducting liquids in the micron-size range, in marked contrast with the cone-jet electrospray whose typical droplet size is in the nanometric regime for these liquids. In contrast with other microdripping regimes where the mass is emitted upon the periodic formation of a narrow capillary jet, the present regime gives one single droplet per oscillation, except for the almost massless fine aerosol emitted in the form of an electrospray.

A double-'blind' placebo-controlled study of nitazoxanide in the treatment of cryptosporidial diarrhoea in AIDS patients in Mexico.

Sixty-six patients with human immunodeficiency virus infection and diarrhoea caused by Cryptosporidium parvum were enrolled in a double-'blind' placebo-controlled study to evaluate the safety and efficacy of nitazoxanide in the treatment of cryptosporidiosis related to the acquired immune deficiency syndrome. Patients were randomly assigned to one of 3 treatment groups and received either 500 mg twice daily of nitazoxanide, 1000 mg twice daily of nitazoxanide, or placebo orally for 14 d; the patients on nitazoxanide then crossed over to placebo while the placebo patients crossed over to nitazoxanide therapy at either the high or low dose depending on their randomization. Three post-treatment faecal examinations were conducted on days 15, 22 and 29 following initiation of treatment: patients were considered 'cured' if none revealed any C. parvum oocysts. Both doses of nitazoxanide produced parasitological cure rates superior to the placebo responses (12/19 [63%, P = 0.016] for patients receiving 1 g/d and 10/15 [67%, P = 0.013] for those receiving 2 g/d). Parasitological cure was correlated with the complete resolution of the diarrhoeal syndrome in 19 of the 22 treated patients who were considered parasitologically cured (86%). Both doses of nitazoxanide were well tolerated by the patients.

Ion evaporation from the surface of a Taylor cone.

An analysis is carried out of the electric field-induced evaporation of ions from the surface of a polar liquid that is being electrosprayed in a vacuum. The high-field cone-to-jet transition region of the electrospray, where ion evaporation occurs, is studied taking advantage of its small size and neglecting the inertia of the liquid and the space charge around the liquid. Evaporated ions and charged drops coexist in a range of flow rates, which is investigated numerically. The structure of the cone-to-jet transition comprises: a hydrodynamic region where the nearly equipotential surface of the liquid departs from a Taylor cone and becomes a jet; a slender region where the radius of the jet decreases and the electric field increases while the pressure and the viscous stress balance the electric stress at the surface; the ion evaporation region of high, nearly constant field; and a charged, continuously strained jet that will eventually break into drops. Estimates of the ion and drop contributions to the total, conduction-limited current show that the first of these contributions dominates for small flow rates, while most of the mass is still carried by the drops.

Liquid flow induced by ion evaporation in an electrified meniscus.

A simple model is proposed for the flow around the apex of a meniscus of a liquid undergoing ion evaporation in a vacuum under the action of a high electric field. The model includes a simplified description of the effect of the space charge surrounding the evaporating surface, and the idealizations that ion evaporation occurs at a constant surface field and that the electric field and viscous forces are negligible in the liquid. In agreement with known experimental and theoretical results for liquid metal ion sources, numerical solutions of the model problem show that the meniscus develops a protrusion and the current-voltage characteristic is linear in a range of voltages above an extinction voltage at which evaporation switches off. An oscillatory regime and transient evolutions ending in surface pinch-off and the emission of a drop are described, and the stabilizing effect of the pressure variations due to the evaporation flux is discussed. Asymptotic estimates for large evaporation flow rates are worked out.

Free-boundary problems describing two-dimensional pulse recycling and motion in semiconductors.

An asymptotic analysis of the Gunn effect in two-dimensional samples of bulk n GaAs with circular contacts is presented. A moving pulse far from contacts is approximated by a moving free boundary separating regions where the electric potential solves a Laplace equation with subsidiary boundary conditions. The dynamical condition for the motion of the free boundary is a Hamilton-Jacobi equation. We obtain the exact solution of the free-boundary problem (FBP) in simple one-dimensional and axisymmetric geometries. The solution of the FBP is obtained numerically in the general case and compared with the numerical solution of the full system of equations. The agreement is excellent so that the FBP can be adopted as the basis for an asymptotic study of the multidimensional Gunn effect.

Axisymmetric pulse recycling and motion in bulk semiconductors.

The Kroemer model for the Gunn effect in a circular geometry (Corbino disks) has been numerically solved. The results have been interpreted by means of asymptotic calculations. Above a certain onset dc voltage bias, axisymmetric pulses of the electric field are periodically shed by an inner circular cathode. These pulses decay as they move towards the outer anode, which they may not reach. As a pulse advances, the external current increases continuously until a new pulse is generated. Then the current abruptly decreases, in agreement with existing experimental results. Depending on the bias, more complex patterns with multiple pulse shedding are possible.

[New alternatives in the treatment of bacterial vaginosis]. / Nuevas alternativas en el tratamiento de la vaginosis bacteriana.

Efficiency and security clindamycin vaginal cream (2%) were compared to oral metronidazole's for the treatment of 184 women with symptomatic bacterial vaginosis in a multicentric, randomized, double-blind, controlled study. The treatment was of 7 days duration, using placebo capsules for the clindamycin group and placebo cream for the metronidazole group. Patients were observed during a follow up (4-13 and 20-43 days after completion of therapy). Global results of this treatment indicated that clindamycin vaginal cream offers a similar efficiency than oral metronidazole. Improvement or total healing was 87% for clindamycin and 79% for metronidazole, with no significant differences (p > 0.22). No relapses were observed in the clindamycin group, and 7% in the metronidazole group. The clindamycin group had a failure rate of 3% compared to 15% in the oral metronidazole group. Both drugs were well tolerated. Side effects more frequently reported were vulvovaginal irritation and cervicitis/vaginitis. The only side effect that could have been classified as serious was a generalized rash in a patient receiving metronidazole. It was concluded that clindamycin vaginal cream (2%) is an efficient and secure alternative to oral metronidazole for the treatment of bacterial vaginosis being the elective therapy for pregnant women in their first gestational trimester.

Computer-based automated left atrium segmentation and volumetry from ECG-gated coronary CT angiography data: comparison with manual slice segmentation and ultrasound planimetric methods.

PURPOSE: Enlargement of the left atrium is a risk factor for cardiovascular or cerebrovascular events. We evaluated the performance of prototype software for fully automated segmentation and volumetry of the left atrium. MATERIALS AND METHODS: In 34 retrospectively ECG-gated coronary CT angiography scans, the end-systolic (LAVsys) and end-diastolic (LAVdia) volume of the left atrium was calculated fully automatically by prototype software. Manual slice segmentation by two independent experienced radiologists served as the reference standard. Furthermore, two independent observers calculated the LAV utilizing two ultrasound planimetric methods ("area length" and "prolate ellipse") on CTA images. Measurement periods were compared for all methods. RESULTS: The left atrial volumes calculated with the prototype software were in excellent agreement with the results from manual slice segmentation (r = 0.97 - 0.99; p < 0.001; Bland-Altman) with excellent interobserver agreement between both radiologists (r = 0.99; p < 0.001). Ultrasound planimetric methods clearly showed a higher variation (r = 0.72 - 0.86) with moderate interobserver agreement (r = 0.51 - 0.79). The measurement period was significantly lower with the software (267 ± 28 sec; p < 0.001) than with ultrasound methods (431 ± 68 sec) or manual slice segmentation (567 ± 91 sec). CONCLUSION: The prototype software showed excellent agreement with manual slice segmentation with the least time consumption. This will facilitate the routine assessment of the LA volume from coronary CTA data and therefore risk stratification.

Equilibrium height of a liquid in a gap between corrugated walls under spontaneous capillary penetration.

A simple and general method is presented to calculate the equilibrium surface of a liquid that penetrates spontaneously, due to capillarity, in the gap between two vertical corrugated plates. Several properties of the equilibrium solution are discussed and the results are backed by a qualitative experiment.

[Interrater reliability of the Spanish version of Schedule for Affective Disorders and Schizophrenia for School-Age Children--Present and Lifetime version (K-SADS-PL)]. / Estudio de fiabilidad interevaluador de la versión en español de la entrevista Schedule for Affective Disorders and Schizophrenia for School-Age Children--Present and Lifetime version (K-SADS-PL).

INTRODUCTION: The K-SADS-PL diagnostic interview is useful for the cross-sectional and longitudinal evaluation of psychopathology in children and adolescents. The objective of this article was to describe the interrater reliability of the Spanish version of the Schedule for Affective Disorders and Schizophrenia for School-Age Children--Present and Lifetime version (K-SADS-PL). METHOD: The interview was translated, back-translated and adapted to Spanish. Forty psychiatric outpatients (aged 6 to 17 years) were evaluated. The interviews were videotaped and scored by three independent raters. All of them included both the child's and parent's interview. Interrater reliability was obtained for affective, anxiety and conduct disorders using the Cohen's kappa coefficient. RESULTS: Kappa coefficients were between the good and excellent range for present and lifetime disorders (major depressive disorder kappa = 0.76, any anxiety disorder kappa = 0.84, attention deficit hyperactivity disorder kappa = 0.91 and conduct disorder, kappa = 1). CONCLUSION: The Spanish version of the K-SADS-PL is a reliable instrument for the assessment of psychopathology in children and adolescents.

Comparison of oral cefuroxime axetil and oral amoxycillin/clavulanate in the treatment of community-acquired pneumonia.

Cefuroxime axetil has been evaluated previously in the treatment of lower respiratory tract infections, but not specifically in the treatment of community-acquired pneumonia. In a multicentre, investigator-blinded clinical trial, 162 patients with community-acquired pneumonia were randomly assigned to receive orally either cefuroxime axetil 500 mg bid (n = 84) or amoxycillin/clavulanate 500 mg/125 mg tid (n = 78) for 10 days. Organisms were isolated from the pretreatment sputum specimens of 97 of 162 (60%) patients, the commonest isolates being Streptococcus pneumoniae (38%) and Haemophilus influenzae (18%). A satisfactory clinical outcome (cure or improvement) was achieved in 100% (55 of 55) and 96% (49 of 51) of the clinically evaluable patients treated with cefuroxime axetil or amoxycillin/clavulanate, respectively (P = 0.23). With respect to eradication of bacterial pathogens, a satisfactory outcome (cure, presumed cure or cure with colonization) was obtained in 94% (32 of 34) and 93% (37 of 40) of bacteriologically evaluable patients treated with cefuroxime axetil or amoxycillin/clavulanate, respectively (P = 1.00). Both treatment regimens used in this study were well tolerated. The most common drug-related adverse experiences were gastrointestinal events, reported by 8% and 4%, respectively, of the patients in the amoxycillin/clavulanate and cefuroxime axetil groups, a difference which was not statistically significant (P = 0.32). These results indicate that cefuroxime axetil twice a day is as effective as amoxycillin/clavulanate three times a day in the treatment of outpatients with mild to moderate community-acquired pneumonia.

HLA antigens associated to amoebic abscess of the liver in Mexican mestizos.

Worldwide prevalence of amoebiasis is estimated at 4 x 10(8) cases/year, yet only one of about 300 individuals harbouring Entamoeba histolytica suffers tissue invasion and these cases are mostly concentrated in certain areas of Asia, Africa and Latin America. Patients with amoebic abscess of the liver (AAL) represent only a small fraction of that. These contrasting figures have been tentatively explained on the one hand through variations in sex, immunocompetence, nutritional and other socioeconomic features of the host, and on the other hand through differences in parasite virulence. In order to explore a possible association between the major histocompatibility complex (MHC) and AAL susceptibility, we studied the HLA profile in 31 Mexican mestizos with AAL and compared it to race and socioeconomically matched controls. Mexican mestizo patients with AAL revealed a significant increase in HLA-Bw16 and HLA-DR3 which could suggest an HLA-related susceptibility to liver invasion by E. histolytica.

Clindamycin vaginal cream vs oral metronidazole in the treatment of bacterial vaginosis.

PIP: This study was designed to compare the safety/efficacy of the treatment of 2% clindamycin vaginal cream and oral metronidazole in 184 women with bacterial vaginosis. This was a randomized, prospective, multicenter, double-blind, controlled study. Patients were randomized to either Clindamycin phosphate vaginal cream 2%, 5 gm intravaginally at bedtime, and placebo oral metronidazole capsules taken twice daily, or oral metronidazole capsules, 500 mg, taken twice daily, and placebo clindamycin vaginal cream, 5 gm to be administered intravaginally at bedtime. All treatments were for 7 days. Patients were seen for followup at 4-13 days and 20-43 days after completion of protocol therapy. 2 investigators in Mexico City enrolled a total of 184 patients (91 clindamycin and 93 metronidazole). 1 patient never received drugs after enrollment, leaving 183 valuable for safety. A total of 114 were valuable for efficacy. Protocol regimens were comparable in efficacy (p=0.22) and the percentage of cure/improvement was 87% in the clindamycin group compared to 79% in the metronidazole group. No relapse was observed in the clindamycin group, as opposed to 7% in the metronidazole group. The clindamycin group had a failure of 13% while this was 15% in the metronidazole group. Both treatments were well-tolerated. Most of the events were either vulvovaginal irritation upon application of the study drug, or the development of vaginitis/cervicitis. The 1 event classified as serious in this study (metronidazole group) was generalized rash which, in the opinion of the investigator, was related to the study drug. There were 4 nongenital tract side effects (1 gastrointestinal, 2 dermatologic, and 1 allergy) all in the metronidazole group. The authors can conclude that clindamycin 2% vaginal cream is at least as effective as orally administered metronidazole for the treatment of bacterial vaginosis in nonpregnant women.^ieng

[Validity and reliability of the Spanish version of Yale-Brown obsessive-compulsive rating scale for children and adolescents]. / Estudio de validez y confiabilidad de la versión en español de la escala Yale-Brown del trastorno obsesivo-compulsivo para niños y adolescentes.

INTRODUCTION: The Children Yale-Brown Obsessive- Compulsive Scale (CY-BOCS) constitutes a very good instrument for the evaluation of obsessive-compulsive disorder (OCD) symptoms, by a clinical interview administered to the patient and parent, that includes summary score of the clinician. OBJECTIVE: We are proposing a Spanish version of instrument, which is rated during a brief clinical interview to the parents and the patients. We are presenting data reliability and validity using two out-patient samples. METHODS: After the translation to Spanish, a back translation and adaptation to Spanish of the CY-BOCS, twenty eight out-patients (75 % male) with a mean age 12.1 (+/- 2.7) from two clinical settings on Mexico City evaluated. Reliability was evaluated by computing the internal consistency (Cronbach's alpha) on all interviews. assess interrater agreement, the interviews were videotaped and scored by three independent raters and all of them included both the child and the parent interview. The CY-BOCS total scored was correlated with the K-SADS-PL diagnosis. RESULTS: The CY-BOCS total score for all subjects was 16.5 +/- 9.8. Cronbach's alpha coefficient was 0.87; Pearson correlation of total CY-BOCS score with the K-SADS-PL diagnosis was 0.60 (p < or = 0.05). The intraclass correlations coefficients for the parents, youngsters and clinician 0.96, 0.94 and 0.92, respectively. CONCLUSIONS: The Spanish version of the CY-BOCS reliable and valid instrument, useful for both clinicians and researchers in child and adolescent OCD assessment.