First report of acaricidal efficacy from plumbagin on larvae of Rhipicephalus microplus and Rhipicephalus sanguineus resistant to conventional acaricides.

The problem of resistance to acaricides in ticks such as Rhipicephalus microplus and R. sanguineus has motivated the search for control alternatives, such as the use of extracts and secondary metabolites from plants. Plumbagin is a natural product present in plants such as Plumbago zeylanica L., Diospyros kaki, and D. anisandra, of which acaricidal activity has been reported. Therefore, the objective of this study was to evaluate in vitro the acaricidal efficacy of plumbagin on larvae of R. microplus and R. sanguineus resistant to conventional acaricides. Larvae from engorged female ticks, collected from naturally infested dairy cattle and domiciled dogs, in Yucatan, Mexico, were used. The larval packet test and the larval immersion test were performed to detect acaricide susceptibility. Both tick populations were detected as resistant to cypermethrin and amitraz. Then, the modified larval immersion test was used and plumbagin was evaluated at concentrations of 1%, 0.5%, 0.25%, and 0.125% (%w/v), obtaining a mortality of 100% in the four concentrations for both tick species. Subsequently, lower doses of plumbagin were evaluated at concentrations of 0.0625%, 0.03125%, 0.015625% and 0.0078125%, obtaining mortalities of 100 to 36.26% for R. microplus and 100%-5.33% for R. sanguineus. Using Probit analysis, lethal concentrations at 50% (LC50), 99% (LC99) and confidence intervals at 95% (CI95%) were calculated. R. microplus showed a LC50 of 0.011% (CI95%: 0.010-0.011) and LC99 of 0.019% (CI95%: 0.018-0.022). R. sanguineus presented a LC50 of 0.017% (CI95%: 0.015-0.018) and CL99 of 0.031% (CI95%: 0.027-0.036). It was concluded that plumbagin has high acaricidal efficacy against larvae of R. microplus and R. sanguineus resistant to amitraz and cypermethrin. R. microplus larvae were significantly more susceptible to LC50 and LC99 compared to R. sanguineus. This is the first report on the acaricidal efficacy of plumbagin on larvae of R. microplus and R. sanguineus resistant to conventional acaricides.

Superlinear Photoluminescence by Ultrafast Laser Pulses in Dielectric Matrices with Metal Nanoclusters.

An intense photoluminescence emission was observed from noble metal nanoclusters (Pt, Ag or Au) embedded in sapphire plates, nucleated by MeV ion-implantation and assisted by an annealing process. In particular, the spectral photoluminescence characteristics, such as range and peak emission, were compared to the behavior observed from Pt nanoclusters embedded in a silica matrix and excited by UV irradiation. Correlation between emission energy, nanoclusters size and metal composition were analyzed by using the scaling energy relation EFermi/N1/3 from the spherical Jellium model. The metal nanocluster luminescent spectra were numerically simulated and correctly fitted using the bulk Fermi energy for each metal and a Gaussian nanoclusters size distribution for the samples. Our results suggest protoplasmonics photoluminescence from metal nanoclusters free of surface state or strain effects at the nanoclusters-matrix interface that can influence over their optical properties. These metal nanoclusters present very promising optical features such as bright visible photoluminescence and photostability under strong picosecond laser excitations. Besides superlinear photoluminescence from metal nanoclusters were also observed under UV high power excitation showing a quadratic dependence on the pump power fluence.

[The severity of rheumatoid arthritis as a timely predictor of instability in the asymptomatic cervical spine]. / La severidad de la artritis reumatoide como predictor oportuno de inestabilidad de la columna cervical asintomática.

INTRODUCTION: Cervical spine involvement is common in patients with RA, risk factors such as disease activity may be related to asymptomatic cervical instability. OBJECTIVE: To determine the associated factors for asymptomatic cervical spine instability in patients with rheumatoid arthritis. MATERIAL AND METHODS: Case and control study from the external spine and rheumatology consultation of a level II trauma center to identify all patients diagnosed with rheumatoid arthritis (RA) and asymptomatic cervical instability. With simple X-rays of the cervical spine, carrying out radiographic measurements, the diagnosis of cervical instability was performed, risk factors such as the presence of rheumatoid factor (FR), previous articular surgeries, elevations of the C-reactive protein (PCR) values were evaluated. The severity and activity of the disease measured in the activity index of 28 articulations (DAS 28) in addition to the index of activity of the simplified disease (SDAI). RESULTS: We assessed 32 patients, nine patients (28.1%) met the criteria for instability of the anterior cervical spine atlantoaxial subluxation (SAAa) (100%), also one patient with SAAa presented vertical subluxation (SV), risk factors more relevant: DAS 28 with an OR = 3.54, SDA with an OR = 2.34 and finally the PCR 1.0 its OR = 2.88. CONCLUSION: The risk factors associated opportunely in our population are the severity of the activity of the disease that we can see in the DAS and SDAI when applied in patients and PCR 1.0.

INTRODUCCIÓN: La afectación de la columna cervical es común en pacientes con artritis reumatoide (AR), factores de riesgo como la actividad de la enfermedad puede estar relacionada con inestabilidad cervical asintomática. OBJETIVO: Determinar los factores asociados a la inestabilidad de la columna cervical asintomáticos en pacientes con artritis reumatoide. MATERIAL Y MÉTODOS: Estudio de casos y controles provenientes de la consulta externa de reumatología y columna de un centro de trauma de nivel II para identificar a todos los pacientes diagnosticados con AR e inestabilidad cervical asintomáticos. Con radiografías simples de la columna cervical que hacen mediciones radiográficas, se realizó el diagnóstico de inestabilidad cervical, se evaluaron los factores de riesgo como la presencia de factor reumatoide (FR), cirugías articulares previas, las elevaciones de los valores de proteína C reactiva (PCR), la severidad y actividad de la enfermedad medida en el índice de actividad de la enfermedad de 28 articulaciones (DAS 28), además del índice de actividad de la enfermedad simplificada (SDAI). RESULTADOS: Se evaluaron 32 pacientes, nueve (28.1%) cumplieron con los criterios para inestabilidad de la columna cervical con subluxación atlantoaxial anterior (SAAa) (100%), también un paciente con SAAa presentaba subluxación vertical (SV), los factores de riesgo más relevantes: el DAS 28 con un OR = 3.54, SDA con un OR = 2.34 y por último el PCR 1.0 su OR = 2.88. CONCLUSIÓN: Los factores de riesgo asociados oportunamente en nuestra población son la severidad de la actividad de la enfermedad que podemos observar en el DAS y SDAI al aplicarlos en los pacientes y PCR 1.0.

Improving preclinic preparation for patients with chronic conditions in quito, ecuador: a randomized controlled trial.

Objectives. As in many settings, patients in community health centers in Ecuador do not complete previsit forms or receive assistance to identify questions and concerns they would like to address in brief clinic visits with physicians. We examined the comparative effectiveness of providing (1) a previsit form to complete; (2) a previsit form along with assistance in completing the form; and (3) usual care. Methods. Parallel, three-arm randomized controlled trial in two health centers serving indigent to low-income communities in Quito, Ecuador, among 199 adult patients who took medications for at least one chronic condition. Outcome measures were self-reported satisfaction with the visit, confidence in asking questions, and extent to which patients' objectives were met. Results. Patients who received assistance in completing a previsit form were more than twice as likely as participants in usual care to report achieving everything they wanted during their visit (AOR 2.2, P = 0.039). There were no differences in any outcomes between the groups who received the previsit form with no assistance and usual care. Conclusions. For high-quality patient-centered primary care, it is important to develop and test innovative and scalable interventions for patients and physicians to make the best use of limited clinic time.

Ultrafast optical phase modulation with metallic nanoparticles in ion-implanted bilayer silica.

The nonlinear optical response of metallic-nanoparticle-containing composites was studied with picosecond and femtosecond pulses. Two different types of nanocomposites were prepared by an ion-implantation process, one containing Au nanoparticles (NPs) and the other Ag NPs. In order to measure the optical nonlinearities, we used a picosecond self-diffraction experiment and the femtosecond time-resolved optical Kerr gate technique. In both cases, electronic polarization and saturated absorption were identified as the physical mechanisms responsible for the picosecond third-order nonlinear response for a near-resonant 532 nm excitation. In contrast, a purely electronic nonlinearity was detected at 830 nm with non-resonant 80 fs pulses. Regarding the nonlinear optical refractive behavior, the Au nanocomposite presented a self-defocusing effect, while the Ag one presented the opposite, that is, a self-focusing response. But, when evaluating the simultaneous contributions when the samples are tested as a multilayer sample (silica-Au NPs-silica-Ag NPs-silica), we were able to obtain optical phase modulation of ultra-short laser pulses, as a result of a significant optical Kerr effect present in these nanocomposites. This allowed us to implement an ultrafast all-optical phase modulator device by using a combination of two different metallic ion-implanted silica samples. This control of the optical phase is a consequence of the separate excitation of the nonlinear refracting phenomena exhibited by the separate Au and Ag nanocomposites.

Tuning the aspect ratio of silver nanospheroids embedded in silica.

A method is proposed to control the aspect ratio (epsilon) of elongated nanoparticles obtained by ion implantation in a transparent matrix. The procedure was tested for Ag spheroids in silica and we could accurately change epsilon in the range from the maximum value obtained by the ion implantation (around 3.0 in this case) to 1.0 (spherical shape). The values of epsilon were determined in several steps from optical extinction spectroscopy measurements, by fitting the modification and splitting of the surface plasmon resonance peak, using the T-matrix method. In the initial (maximum deformation) and final (undeformed) states, transmission electron microscopy images were obtained, showing a good agreement with the T-matrix results in both cases.

Anticancer drug discovery and development throughout the world.

This year's American Society of Clinical Oncology International Symposium devoted 2 hours to a lively discussion of various aspects of anticancer drug discovery and development throughout the world. The scientific program started with an overview of efforts directed toward promoting international collaboration in natural product-derived anticancer drug discovery. This was followed by a discussion on the importance of interethnic differences and pharmacogenetics in anticancer drug development. Thereafter, this part of the program was completed by a description of the activities of the newly created Singapore-Hong Kong-Australia Drug Development Consortium and an overview of the contribution of Japan to anticancer drug development. The logistics and regulatory aspects of clinical trials with new anticancer agents in different parts of the world were then presented, with an emphasis on Europe, North America, and Japan. The program was completed with a panel discussion of the efforts to harmonize the exchange of clinical data originating from one region of the globe with other territories, with input from official representatives of the United States Food and Drug Administration and the Medical Devices Evaluation Center of Japan.

Comparison of extraction methods and detection systems in the gas chromatographic analysis of volatile carbonyl compounds.

High-resolution gas chromatography (HRGC) with electron-capture detection (ECD), nitrogen-phosphorus detection (NPD), flame ionization detection (FID) or with mass spectrometry-selected ion monitoring (MS-SIM) was used in the analysis of volatile carbonyl compounds. Eighteen carbonyl compounds that are typically produced during lipid peroxidation were derivatized quantitatively with pentafluorophenylhydrazine (PFPH) at room temperature, to afford their corresponding water-insoluble hydrazones. These derivatives were extracted into non-polar phases by means of either liquid-liquid extraction (LLE) (hexane) or solid-phase extraction (SPE) on 3 ml C18 octadecyl-bonded phase cartridges. Detection limits of 10(-14) and 10(-12) mol/ml per aldehyde were achieved with the ECD and MS-SIM systems, respectively. The effects of extraction conditions on sensitivity and recovery were determined by performing parallel HRGC-ECD and HRGC-MS-SIM analyses of pentafluorophenylhydrazones of the eighteen compounds under study. Recoveries of 51.4-78.9 +/- 1.2-4.5 and 80.9-98.3 +/- 1.0-3.5% were obtained with LLE and SPE, respectively. The method was applied to the analysis of the volatile carbonyl compounds in various heated vegetable oils (corn, palm or sunflower) and to the analysis of volatile aldehydes in human urine.

Obstrucción de la unión pieloureteral en niños y adolescentes: estudio y tratamiento / Obstruction of the pyelouretheral junction in children and adolescents: study and treatment

Se presenta un estudio retrospectivo de 84 pacienes que en el período comprendido entre enero del 86 y agosto del 95 fueron sometidos a una ureteropieloplastía. La Orografía intravenosa realizada a los 6 meses de la intervención mostró ausencia de dilatación en 20 riñones 56 con ectasia residual (95 por ciento de exito). Anulación en un caso y persistencia de la obtrucción en 3 casos. 9 pacientes no acudieron al control. Se presentaron complicaciones en 8 pacientes (8,9 por ciento). Dado el carácter histórico de nuestra serie tenemos una baja incidencia de diagnóstico prenatal de obtrucción de la UPU. 21 por ciento, que en las series actuales se acerca al 70 por ciento gracias al uso sístemático de la ecografía durante el embarazo. El diagnóstico prenatal nos pemitiría llevar a cabo la reparación de la obtrucción de la UPU lo más precozmente posible. Ya que parece existir un menor índice de complicaciones.con un mayor índice de éxitos en los grupos de menor edad

Neonatal screening for sickle cell disease: a cost-effectiveness analysis.

PURPOSE: To determine the cost-effectiveness of screening newborn infants for sickle cell disease. DESIGN: We developed a decision model that examined two strategies: (1) screening neonates and administering penicillin to infants found to have sickle cell disease in the hope of preventing pneumococcal sepsis, and (2) not screening but administering penicillin to infants after symptoms of sickle cell disease develop. The model calculates the cost-effectiveness of these strategies during the first 3 years of life. We applied the model to three prototypic populations of neonates--black, nonblack with a relatively high prevalence of hemoglobin S genes, and nonblack with a low prevalence of hemoglobin S genes. DATA IDENTIFICATION: We obtained from the published literature the effectiveness and risk of penicillin prophylaxis, the risk of pneumococcal sepsis, and the probability that in infants not screened the development of symptoms would lead to the discovery of sickle cell disease within the first 3 years of life; we used the published literature and the Hardy-Weinberg law to determine the prevalence of sickle cell disease. We used actual variable costs of screening, antibiotic prophylaxis, and hospitalization for pneumococcal sepsis or anaphylaxis. RESULTS: Screening and then treating affected black infants costs only $3100 more per life saved than not screening. Screening nonblack populations with a high prevalence of hemoglobin S genes would cost $1.4 million per life saved, and screening low prevalence populations would cost $450 billion per life saved. CONCLUSIONS: Screening black infants is very worthwhile, but screening populations in which the hemoglobin S gene is rare is unjustified.

Evaluación de las subpoblaciones linfocitarias CD4+ y CD8+ en adultos infectados con el virus de la inmunodeficiencia humana (VIH) / valuation of CD4+ and CD8+ lymphocyte subpopulation in adults infected with the human immunodeficiency virus

Se presentan los resultados de la evaluación de las subpoblaciones linfocitarias CD4+ y CD8+ en 127 adultos cubanos, infectados con el virus de la inmunodeficiencia humana (VIH) y acogidos a tratamiento sanatorial. En comparación con el grupo control, se encontró una disminución significativa de las células CD4 en los infectados con VIH (32,2+13.3 vs. 48,2 + 10,4 %: p<0,01), un incremento significativo en las células CD8+ (39,3 + 12,4 % vs. 26,5 + 10.2 %, p<0,01) y una disminución de la relación CD4/CD8 (0,9 + 0.6 vs. 2,0 + 0,7: p<0,01). Cuando los seropositivos al VIH se agruparon según su clasificación clínica después del ingreso en el sanatorio, tanto en los asintomáticos como en los casos con linfoadenopatía persistente generalizada y en los que presentaron otras complicaciones incluyendo el SIDA, se detectaron individuos con disminución de la relación CD4/CD8 desde su ingreso. Sin embargo, en los asintomáticos esta alteración se presentó sólo en el 28 % de los casos, mientras que en los pacientes sintomáticos el 37 % tenía esta alteración. El nivel de linfocitos T CD4+ no permitió diferenciar a los individuos clinicamente más afectados del resto de los infectados con VIH

[Management of traumatic injuries of the colon]. / El manejo de las heridas traumáticas del colon.

We have reviewed our experience with penetrating lesions of the colon at the Santo Tomás Hospital. Good results were obtained with immediate suture of the lesions without need for colostomy when favorable conditions permit.

Avaliaçäo nutricional no paciente oncológico / Nutritional evaluation in oncologia patients

Os autores avaliam nutricionalmente 87 doentes do Serviço de Cirurgia Gastrenterológica do Hospital do Ipiranga do INAMPS, Säo Paulo. Desses, 32 säo portadores de neoplasias e 55 de afecçöes simples sem suspeita clínica de má-nutriçäo. Os parâmetros medidos foram peso, altura, albumina e transferrina sérica, PCT e resposta ao PPD intradérmico. Discute-se a praticidade de cada método e sua capacidade de reconhecer a má nutriçäo. Na comparaçäo entre os grupos, o peso, a albumina e a PCT distinguem-se como método de avaliaçäo nutricional na abordagem inicial do paciente oncológico

Regresión espontánea del hemangioendotelioma múltiple juvenil del hígado / Spontaneous regression of hepatic hemangioendothelioma in adolescent

Se presentan tres casos de Hemangioendotelioma Múltiple Juvenil de la Unidad de Investigación en Nutrición y Gastroenterología Infantil del Hospital Miguel Pérez Carreño durante el período 1979-1985. Este tumor vascular benigno pero poco frecuente puede presentar problemas considerables tanto en el diagnóstico como en el tratamiento. El diagnóstico se basó en la tríada clínica de hepatomegalia, anemia e insuficiencia cardíaca con pruebas de funcionalismo hepático conservado y se confirmó con gammagrafía en los tres casos y ultrasonido y biopsia hepática en uno de ellos. El tratamiento médico fue efectivo en el control de los síntomas observándose en los tres casos una regresión espontánea del tumor