[Results of vagal nerve stimulation in patients with pharmacoresistant epilepsy in a national epilepsy referral centre]. / Resultados de la estimulacion del nervio vago en pacientes con epilepsia farmacorresistente en un centro de referencia nacional de epilepsia.

AIM: To describe clinical results and complications derived from vagal nerve stimulation therapy in drug resistant epileptic patients unsuitable for other surgical treatments, since the first implant in an epilepsy national referral centre. PATIENTS AND METHODS: A retrospective analysis of the patients implanted in our centre was held. Data related to baseline characteristics of their epilepsy and therapy complications was collected. RESULTS: 32 new implants in 31 patients are included, mean age of 34 years, 29.3 years of disease evolution, three anti-epileptic drugs at surgery and a postoperative follow-up of 4.03 years. Complex partial seizures types (71.9%) and cryptogenic aetiology (59.4%) were the most frequent. 75% of patients hadn't history of previous epilepsy surgery. 43.8% of patients had a seizure frequency improvement above 50%, with a better response in patients with complex partial seizures (p = 0.22) and cryptogenic aetiology. None statistical significance was found between antiepileptic drugs and seizure frequency. Dysphonia, hoarseness and dysphagia, mostly transient, were the side effects registered. There was an asystole during surgery, completely recovered. One device was replaced due to hardware rupture after a seizure related trauma, one had to be adjusted due to a previous vocal cord paresis, and one dysfunctioning device was removed. In 84.4% the tolerance was excellent. CONCLUSIONS: Vagal nerve stimulation is an effective treatment for significant seizure frequency improvement of resistant patients untreatable with other medical or surgical treatments. Further studies are needed to predict the individual response of each patient to therapy and optimizing indications, therefore contributing to cost/benefit optimization.

TITLE: Resultados de la estimulacion del nervio vago en pacientes con epilepsia farmacorresistente en un centro de referencia nacional de epilepsia.Objetivos. Describir los resultados clinicos y complicaciones derivados de la estimulacion vagal en pacientes con epilepsia farmacorresistente no tributaria de otras modalidades de tratamiento quirurgico, desde el primer implante en un centro de referencia nacional. Pacientes y metodos. Se realizo un analisis retrospectivo de los pacientes implantados en nuestro centro y se extrajeron datos relativos a las caracteristicas basales de su epilepsia y complicaciones derivadas. Resultados. Se incluyeron 32 nuevos implantes en 31 pacientes, con una edad media de 34 años, evolucion de enfermedad de 29,3 años, tres farmacos antiepilepticos prequirurgicos y 4,03 años de seguimiento. Las crisis parciales complejas (71,9%) y criptogenicas (59,4%) fueron el tipo y la etiologia de crisis mas frecuentes. El 75% no tenia antecedentes quirurgicos de epilepsia. Un 43,8% presento mejoria igual o superior al 50%, mayor en las epilepsias parciales complejas (p = 0,22) y la etiologia criptogenica. No se hallo asociacion estadistica entre ajustes de medicacion y frecuencia de las crisis. Los efectos secundarios encontrados fueron disfonia, ronquera y disfagia transitorias, y una asistolia intraoperatoria recuperada. Se realizo un recambio por ruptura de hardware postraumatica. Un paciente con paresia preexistente de cuerda vocal presento estridor laringeo que requirio ajuste de intensidad, y se produjo una retirada del sistema por disfuncion. En el 84,4%, la tolerancia fue excelente. Conclusiones. Constituye un tratamiento efectivo para mejorar significativamente la frecuencia de crisis de los pacientes farmacorresistentes y con contraindicacion para otras modalidades de tratamiento quirurgico. Se precisan futuros estudios para predecir la respuesta individual de cada paciente, optimizar las indicaciones y mejorar la relacion coste/beneficio.

Absence of CD38 delays arrival of neutrophils to the liver and innate immune response development during hepatic amoebiasis by Entamoeba histolytica.

To define the role of CD38 in the migration of neutrophils to the liver and consequently in the induction of an innate immune response during murine hepatic amoebiasis by Entamoeba histolytica, we examined amoebic liver abscess development (ALA), presence of amoebae and neutrophils, and expression levels of cytokines and other inflammation mediators mRNA, in infected wild-type and CD38 Knockout (CD38KO) C57BL/6J mice. Results showed that CD38KO mice undergo a delay in ALA development in comparison with the wild-type strain. The presence of amoebae lasted longer in CD38(-/-), and although neutrophils arrived to the liver in both strains, there was a clear difference in the time between the two strains; whereas in the wild-type strain, neutrophils arrived at early times (6-12 h), in the CD38KO strain, neutrophils arrived later (48-72 h). Cytokines profile during the innate immune response development (TNF-α, IL-1ß, IL-6) was, for WT mice concomitant with, and preceded, for CD38KO mice, the time in which neutrophils were present in the liver lesion. In conclusion, CD38 is important for neutrophils migration during hepatic amoebiasis, and in turn, these cells play an important role in the innate immune response.

Nitrite oxidation inhibition by hydroxylamine: experimental and model evaluation.

A proposed approach for biological nitrogen removal significantly reduces cost by reducing biomass production and carbon requirements via inhibition of nitrite oxidation (NO2- to NO3-). Batch experiments were conducted to examine the effect of hydroxylamine (HM) on nitrite oxidizers, ammonia oxidizers, and nitrite reducers. Hydroxylamine effect experiments were done at initial pH values of 7.4-8.4, nitrogen concentrations of 100 mg N/L, biomass concentrations of 100-400 mg VSS/L and HM dosages up to 43 mg/L. Nitrite oxidizer activity was completely inhibited by HM at dosages of 7.0 and 8.9 mg/L for pH values of 8.4 and 7.6, respectively. Relatively low HM concentrations (0.35-5.5 mg/L) can be used to completely inhibit nitrite oxidation, but do not significantly affect ammonia oxidizers and nitrite reducers. A model developed to describe the effect of pH on nitrite oxidation rate fits the data well (R2 = 0.89) with values for Vmax of 0.372 (mg N/mg VSS-hr), pH* of 7.72, and the inhibition constant Kh of 0.154. Incorporation of HM inhibition into the model provided a good fit to relative nitrite oxidation rate as a function of undissociated HM concentration (R2 = 0.80, Vmax = 0.028 mg N/mg VSS-hr, pH = 7.89, Kh = 0.302, a = 0.195, and Ki= 0.277 mg/L).

Human papillomavirus: a highly prevalent sexually transmitted disease agent among female sex workers from Mexico City.

BACKGROUND: Cervical cancer, a human papillomavirus (HPV)-caused neoplasia, is highly prevalent in Mexico. GOAL: To determine the prevalence of HPV infection in female sex workers (FSW) from Mexico City and to assess the association between HPV infection and the characteristics of these women. STUDY DESIGN: A questionnaire was applied to 495 FSW. Cervical cell specimens were obtained for DNA amplification and hybridization to detect 27 HPV types. A risk factor analysis was performed. RESULTS: The overall prevalence of HPV infection was 48.9%. The prevalence of high-risk HPV types was 43%, whereas that of low-risk types was 24.6%. A total of 18.8% of study participants was infected with both high-risk and low-risk HPV types, and 28.5% were infected with two or more HPV types. Younger age and failure to use a condom were independently associated HPV risks (odds ratio, 7.3 and 2.3; 95% CI, 3.5-15.0 and 1.2-4.4, respectively). CONCLUSIONS: Infection with high-risk and multiple HPV types is high among Mexican FSW. This study corroborated a higher infection rate in younger women. A higher risk of HPV infection is also observed in women who have been involved with sex work for less than 1 year. However, condom use showed a protective effect against HPV infection.

Modeling reduction of uranium U(VI) under variable sulfate concentrations by sulfate-reducing bacteria.

The kinetics for the reduction of sulfate alone and for concurrent uranium [U(VI)] and sulfate reduction, by mixed and pure cultures of sulfate-reducing bacteria (SRB) at 21 +/- 3 degrees C were studied. The mixed culture contained the SRB Desulfovibrio vulgaris along with a Clostridium sp. determined via 16S ribosomal DNA analysis. The pure culture was Desulfovibrio desulfuricans (ATCC 7757). A zero-order model best fit the data for the reduction of sulfate from 0.1 to 10 mM. A lag time occurred below cell concentrations of 0.1 mg (dry weight) of cells/ml. For the mixed culture, average values for the maximum specific reaction rate, V(max), ranged from 2.4 +/- 0.2 micromol of sulfate/mg (dry weight) of SRB. h(-1)) at 0.25 mM sulfate to 5.0 +/- 1.1 micromol of sulfate/mg (dry weight) of SRB. h(-1) at 10 mM sulfate (average cell concentration, 0.52 mg [dry weight]/ml). For the pure culture, V(max) was 1.6 +/- 0.2 micromol of sulfate/mg (dry weight) of SRB. h(-1) at 1 mM sulfate (0.29 mg [dry weight] of cells/ml). When both electron acceptors were present, sulfate reduction remained zero order for both cultures, while uranium reduction was first order, with rate constants of 0.071 +/- 0.003 mg (dry weight) of cells/ml. min(-1) for the mixed culture and 0.137 +/- 0.016 mg (dry weight) of cells/ml. min(-1) (U(0) = 1 mM) for the D. desulfuricans culture. Both cultures exhibited a faster rate of uranium reduction in the presence of sulfate and no lag time until the onset of U reduction in contrast to U alone. This kinetics information can be used to design an SRB-dominated biotreatment scheme for the removal of U(VI) from an aqueous source.

Hepatitis B markers in men seeking human immunodeficiency virus antibody testing in Mexico City.

OBJECTIVES: To estimate the prevalence and associated risk factors of hepatitis B virus (HBV) serologic markers in 1,377 men with high-risk sexual behavior attending a center for human immunodeficiency virus (HIV) detection in Mexico City. METHODS: The study population consisted of all men who were tested for HIV from March to September, 1992. Study participants responded to a standardized questionnaire and provided a blood sample for serology. RESULTS: A total of 1.9% of the population were hepatitis B surface antigen (HBsAg) carriers, and there was a significant difference in HBsAg prevalence between HIV-negative (0.8%) and HIV-positive individuals (7.9%). Sexual preference was associated with HBsAg prevalence; only 0.3% of men who had female sexual partners exclusively were HBsAg carriers, compared with 4.8% of men who had male sexual partners exclusively. Prevalence of antibodies to hepatitis B core antigen (anti-HBc) was 15.4%. However, men who reported only female partners had a 4.6% prevalence, whereas men who had only male partners had a 30.4% prevalence. Logistic regression analysis demonstrated an association of anti-HBc prevalence with age, marital status, sexual preference, seropositivity for HIV, and antibodies to herpes simplex virus type 2. CONCLUSIONS: These data demonstrate that coinfection with HBV is common in the HIV-positive men studied. The highest prevalences of HBsAg and anti-HBc were observed among homosexual men. These results highlight the need to intensify safe-sex education campaigns and to promote hepatitis B vaccination especially among this population group.

[Prevalence of antibodies to Pneumocystis carinii in subjects with high risk behavior for AIDS]. / Prevalencia de anticuerpos contra Pneumocystis carinii en sujetos con prácticas de alto riesgo de SIDA.

P. carinii pneumonia affects more than 80% of patients with AIDS in developed countries. In Mexico this complication has been described in 12 to 23% of patients with AIDS, and it has been proposed that competitive disease such as TB and the low life expectancy of AIDS patients in Mexico are the possible explanations of this low percentage. However, in Mexico the frequency with which the population at risk of contracting AIDS is exposed to P. carinii is unknown. Therefore, we looked for P. carinii antibodies in a group of blood samples obtained in an AIDS detection center in Mexico City. A Western blot analysis was performed on 157 blood samples from homosexual and bisexual men and on 21 from female partners of HIV positive men. Positive results were obtained for 76.9% of the samples. No difference was observed in the frequency of P. carinii antibodies between HIV positive and negative individuals. Also, no differences by sex or age were found. Prevalence of P. carinii antibodies in this group is 76.9%, similar to that found in a comparable group in the U.S.

Ruthenium red adsorption method for measurement of extracellular polysaccharides in sludge flocs.

A nondestructive method of measuring extracellular polysaccharides (ECP) in activated sludge floes using Ruthenium Red dye adsorption was developed at the Environmental Engineering Laboratory at the University of Colorado at Boulder. The effects of pH, buffer solution, dye concentration, sludge mass, temperature, and incubation time on dye adsorption was determined. Ruthenium Red dye adsorption to bacterial floes was found to fit a Brunauer-Emmett-Teller (BET) isotherm model. Of the other environmental conditions in the system, pH was found to have the strongest effect on dye adsorption to bacterial flocs. The amount of extra cellular polysaccharides (ECP) measured by Ruthenium Red adsorption was compared with extracellular polysaccharides measured by two chemical extraction methods. Of all methods considered Ruthenium Red dye adsorption measured the highest amount of extracellular polysaccharide with the lowest amount of bacterial cell disruption. Thus, Ruthenium Red dye adsorption was more effective than extraction procedures for measurement of extracellular polysaccharides in activated sludge flocs.

Incidencia de la arteria cilio-retinal en la población chilena / Incidence of the cilliar retinal artery in chilean population

Se estudia una población chilena de 567 pacientes (1.134 ojos) de consulta por morbilidad oftalmológica general, en busca de la Arteria Cilioretinal. Se determina una frecuencia de 26,2% en el grupo de pacientes y de 15,9% en el total de ojos, siendo más frecuente en hombres. Fue bilateral en 5,6% del grupo y en 21,5% de todas las ACR encontradas. La ubicación más frecuente es temporal (97%) y la longitud en 76,4% mayor de 1 diámetro discal (1,5 mm). Se determina alta correlación (93,3%) entre el diagnóstico oftalmoscópico y la confirmación angliográfica