Molecular and Serological Identification of Anaplasma marginale and Borrelia burgdorferi in Cattle and Ticks from Nuevo Leon, Northern Mexico.

Ticks and tick-borne diseases affect livestock productivity and cause significant economic losses. Therefore, surveillance of these pathogens and vectors is paramount to reducing these effects in livestock. This study aimed to identify Anaplasma marginale and Borrelia burgdorferi sensu lato in ticks collected from cattle. Molecular biology techniques were utilized to identify A. marginale for both types of samples, i.e., ticks and bovine blood. Serology of cattle using indirect immunofluorescence assay (IFA) was conducted to determine antibodies to B. burgdorferi s.l. from seven locations in Nuevo Leon, Mexico, between 2015 and 2017. From 404 bovines, 2880 ticks were collected: Rhipicephalus microplus (2391 females and 395 males), Amblyomma spp. (51 females and 42 males) and Dermacentor variabilis (1 female). Rhipicephalus microplus represented the largest specimens captured, with 96.7% within the seven study sites. PCR processed only 15% (442) of tick samples to identify A. marginale. Field genera proportions were followed to select testing tick numbers. Results showed that 9.9% (44/442) of A. maginale infected the pooled tick species, whereas the highest percent corresponded to 9.4% (38/404) in R. microplus. Regarding the molecular analysis of blood samples, 214 of 337 (63.5%) were positive for A. maginale. In each of the seven locations, at least one bovine sample tested positive for A. maginale. Borrelia burgdorferi s.l. was not found either in the ticks or serum samples. Two A.marginale DNA nucleotide sequences obtained in this study were deposited in the GenBank with the following accession numbers OR050501 cattle, and OR050500 R.microplus tick. Results of this work point to current distribution of bovine anaplasmosis in northern Mexico.

A smart school routing and scheduling problem for the new normalcy.

One of the critical actions that emerged during the onset of the New Normalcy after COVID-19 lockdowns, is the safe return to schools and workplaces. Therefore, dedicated transportation services need to adapt to meet new requirements such as arrival reliability for multiple bell times, the consequent staggering of arrivals and departures, and the decrease in bus capacity due to the physical distancing required by regulators. In this work, we address these issues plus additional labor conditions concerning drivers for a university context; with the goal of optimizing social interests such as covering demand and travel time under limited resources. We propose a bi-level approach, where firstly a bus routing generation sub-problem is solved before a bus scheduling sub-problem. This (strategic) solution is then considered as the baseline for subsequent dynamic (operational) routing. The latter is based on real-time demand provided by the students via a mobile app and considers stop-skipping to further minimize travel time. This integrated transport solution was tested in a university case, showing that with the same resources, it can meet these new requirements. In addition, numerical experimentation was also carried out with benchmark instances to identify, among available and literature-recommended solution algorithms and an effective tailored Tabu Search implementation, those that perform best for this type of problems.

Photodegradation of Rituximab and Critical Evaluation of Its Sensibility to Electromagnetic Radiation.

Rituximab is a monoclonal antibody used in the treatment of lymphoma non-Hodgkin. This mAb is photosensitive as it is administrated to the patient by infusion/perfusion; therefore, photostability is a decisive factor in the efficacy of this biologic. To better understand the photodegradation mechanisms of Rituximab, this biologic was exposed to different irradiance conditions. We show in this study that this mAb photodegrade proportionally to irradiance intensities. The main modifications of Rituximab by irradiance correlate to the increase in aggregates, decrease in its Tm, acidic charge variants, oxidation of the Trp (36) in the heavy chain, and decrease in complement-dependent cytotoxicity (CDC) potency. To understand the relationship between real-life photo-exposition conditions and ICH standardized light tests, a full characterization was set up. Worst photo-stress cases were evaluated, 1 and 2 h under direct sunlight through a window, mimicking the ID65 electromagnetic radiation profile. Our results show that only exposition to direct sun irradiance during 2 h, (≈ 150 kluxes•h), increases critically soluble and insoluble aggregates, diminishing Tm, increasing acidic charge variants, and the photooxidation of the Trp (36) in the heavy chain measured by peptide mapping-RP-UPLC-MS. A decrease in CDC below 80% resulted under this condition, which correlates with physicochemical analyses. While inside light-room exposition (similar to ICH test) and ICH conditions do not have any contribution to the degradation of Rituximab measured by these physicochemical and biological analytical methods. These results indicate that exposition of Rituximab to below ≈ 75 kluxes•h of sun light cannot photodegrade critically this biologic inside of its primary container.

Diethylcarbamazine as potential treatment of COVID-19 lung fibrosis.

Diethylcarbamazine, the antiparasitic drug, also possesses anti-inflammatory and immunomodulatory activities. The anti-fibrotic activity of diethylcarbamazine makes it a potential candidate to treat coronavirus disease 2019 (COVID-19)-related pulmonary fibrosis. Experimental and clinical studies should assess this possible effect.

Field Effectiveness of Drones to Identify Potential Aedes aegypti Breeding Sites in Household Environments from Tapachula, a Dengue-Endemic City in Southern Mexico.

Aedes aegypti control programs require more sensitive tools in order to survey domestic and peridomestic larval habitats for dengue and other arbovirus prevention areas. As a consequence of the COVID-19 pandemic, field technicians have faced a new occupational hazard during their work activities in dengue surveillance and control. Safer strategies to monitor larval populations, in addition to minimum householder contact, are undoubtedly urgently needed. Drones can be part of the solution in urban and rural areas that are dengue-endemic. Throughout this study, the proportion of larvae breeding sites found in the roofs and backyards of houses were assessed using drone images. Concurrently, the traditional ground field technician's surveillance was utilized to sample the same house groups. The results were analyzed in order to compare the effectiveness of both field surveillance approaches. Aerial images of 216 houses from El Vergel village in Tapachula, Chiapas, Mexico, at a height of 30 m, were obtained using a drone. Each household was sampled indoors and outdoors by vector control personnel targeting all the containers that potentially served as Aedes aegypti breeding sites. The main results were that the drone could find 1 container per 2.8 found by ground surveillance; however, containers that were inaccessible by technicians in roofs and backyards, such as plastic buckets and tubs, disposable plastic containers and flowerpots were more often detected by drones than traditional ground surveillance. This new technological approach would undoubtedly improve the surveillance of Aedes aegypti in household environments, and better vector control activities would therefore be achieved in dengue-endemic countries.

Near misdiagnosis of acute HIV-infection with ELISA-Western Blot scheme: Time for mindset change.

Some HIV-infection diagnostic guidelines and health care providers still rely on the ELISA-Western blot diagnostic algorithm. We present a near misdiagnosis case with discordant test results and a lack of proper counseling. We point out the need for an assertive update of health care providers on diagnostic HIV-tests.

Furosemide stress test and interstitial fibrosis in kidney biopsies in chronic kidney disease.

BACKGROUND: Interstitial fibrosis (IF) on kidney biopsy is one of the most potent risk factors for kidney disease progression. The furosemide stress test (FST) is a validated tool that predicts the severity of acute kidney injury (especially at 2 h) in critically ill patients. Since furosemide is secreted through the kidney tubules, the response to FST represents the tubular secretory capacity. To our knowledge there is no data on the correlation between functional tubular capacity assessed by the FST with IF on kidney biopsies from patients with chronic kidney disease (CKD). The aim of this study was to determine the association between urine output (UO), Furosemide Excreted Mass (FEM) and IF on kidney biopsies after a FST. METHODS: This study included 84 patients who underwent kidney biopsy for clinical indications and a FST. The percentage of fibrosis was determined by morphometry technique and reviewed by a nephropathologist. All patients underwent a FST prior to the biopsy. Urine volume and urinary sodium were measured in addition to urine concentrations of furosemide at different times (2, 4 and 6 h). We used an established equation to determine the FEM. Values were expressed as mean, standard deviation or percentage and Pearson Correlation. RESULTS: The mean age of the participants was 38 years and 44% were male. The prevalence of diabetes mellitus, hypertension and diuretic use was significantly higher with more advanced degree of fibrosis. Nephrotic syndrome and acute kidney graft dysfunction were the most frequent indications for biopsy. eGFR was inversely related to the degree of fibrosis. Subjects with the highest degree of fibrosis (grade 3) showed a significant lower UO at first hour of the FST when compared to lower degrees of fibrosis (p = 0.015). Likewise, the total UO and the FEM was progressively lower with higher degrees of fibrosis. An inversely linear correlation between FEM and the degree of fibrosis (r = - 0.245, p = 0.02) was observed. CONCLUSIONS: Our findings indicate that interstitial fibrosis correlates with total urine output and FEM. Further studies are needed to determine if UO and FST could be a non-invasive tool to evaluate interstitial fibrosis. TRIAL REGISTRATION: ClinicalTrials.gov NCT02417883.

Chemokine profile in Alzheimer's disease: Results from a Mexican population.

Alzheimer's Disease (AD) is the main cause of dementia worldwide. Inflammatory cytokines and chemokines are related to different stages of AD and may be related to the progression of the disease. A Case-control study of AD patients healthy, age and sex-matched controls was carried out at the University Hospital "Dr. José E. Gonzalez", UANL. Cytokines and chemokines were measured from blood samples taken from the cubital vein after 8 h of fast. We included 78 subjects from which 29 had AD and 49 were healthy controls. CTACK (p = 0.003), MIG (p = 0.043) and SDF-1α (p = 0.001) were increased in subjects with AD, whereas no change was observed in other cytokines and chemokines. CTACK, MIG and SDF-1α are present in the Central Nervous System and are related to inflammation and endothelial dysfunction. Longitudinal studies evaluating the change of these chemokines in AD are needed to understand their role in AD progression and possibly lead to new diagnostic and therapeutic targets.

Process signatures in glatiramer acetate synthesis: structural and functional relationships.

Glatiramer Acetate (GA) is an immunomodulatory medicine approved for the treatment of multiple sclerosis, whose mechanisms of action are yet to be fully elucidated. GA is comprised of a complex mixture of polypeptides with different amino acid sequences and structures. The lack of sensible information about physicochemical characteristics of GA has contributed to its comprehensiveness complexity. Consequently, an unambiguous determination of distinctive attributes that define GA is of highest relevance towards dissecting its identity. Herein we conducted a study of characteristic GA heterogeneities throughout its manufacturing process (process signatures), revealing a strong impact of critical process parameters (CPPs) on the reactivity of amino acid precursors; reaction initiation and polymerization velocities; and peptide solubility, susceptibility to hydrolysis, and size-exclusion properties. Further, distinctive GA heterogeneities were correlated to defined immunological and toxicological profiles, revealing that GA possesses a unique repertoire of active constituents (epitopes) responsible of its immunological responses, whose modification lead to altered profiles. This novel approach established CPPs influence on intact GA peptide mixture, whose physicochemical identity cannot longer rely on reduced properties (based on complete or partial GA degradation), providing advanced knowledge on GA structural and functional relationships to ensure a consistent manufacturing of safe and effective products.

Design of a strong cation exchange methodology for the evaluation of charge heterogeneity in glatiramer acetate.

Complex pharmaceuticals are in demand of competent analytical methods able to analyze charge heterogeneity as a critical quality attribute (CQA), in compliance with current regulatory expectations. A notorious example is glatiramer acetate (GA), a complex polypeptide mixture useful for the treatment of relapsing-remitting multiple sclerosis. This pharmaceutical challenges the current state of analytical technology in terms of the capacity to study their constituent species. Thus, a strong cation exchange methodology was designed under the lifecycle approach to support the establishment of GA identity, trough the evaluation of its chromatographic profile, which acts as a charge heterogeneity fingerprint. In this regard, a maximum relative margin of error of 5% for relative retention time and symmetry factor were proposed for the analytical target profile. The methodology met the proposed requirements after precision and specificity tests results, the former comprised of sensitivity and selectivity. Subsequently, method validation was conducted and showed that the method is able to differentiate between intact GA and heterogeneity profiles coming from stressed, fractioned or process-modified samples. In summary, these results provide evidence that the method is adequate to assess charge heterogeneity as a CQA of this complex pharmaceutical.

Los idiomas del cuerpo: un estudio de caso sobre una paciente con epilepsia bifocal fármacorresistente

El autor del presente trabajo realiza un estudio de caso teórico-clínico acerca de un paciente que presenta un cuadro epiléptico bifocal fármacorresistente, detectable en el encefalograma, alternado con pseudocrisis epilépticas (histeroepilepsia), lo que lo lleva a cuestionarse, por un lado, sobre el alto porcentaje (30%) de pacientes epilépticos fármacorresistentes y su relación con los trastornos psicosomáticos; así como sobre la combinación en un mismo paciente de dos niveles de funcionamiento psíquico: uno narcisista no neurótico (las epilepsias como un trastorno psicosomático) y un funcionamiento neurótico histérico conversivo (las pseudocrisis). La importancia de dicho trabajo reside en el aumento en la consulta de pacientes con trastornos narcisistas no neuróticos, en los que se encuentran los trastornos psicosomáticos, así como en el difícil manejo (y alto porcentaje) de los pacientes epilépticos refractarios, que desde la neurología y la psiquiatría han representado un reto no resuelto y donde la clínica psicoanalítica tiene un saber por aportar.

The author of this paper builds a theoretical and clinical case study, based on a patient presenting with drug resistant bifocal epilepsy, detectable by EEG, that alternates with epileptic pseudoseizures (hystero-epilepsy) that rises the question on one side, about the high percentage (30%) of drug-resistant epileptic patients and its relationship with psychosomatic disorders; and, on the other, the combination of two levels of psychic functioning with the same patient: a non-neurotic narcissist (epilepsy as a psychosomatic disorder) and a functioning neurotic hysterical conversive operation (the pseudoseizures). The importance of this work lies in the increased consultation of patients with non-neurotic narcissistic disorders, among which are psychosomatic disorders, as well as the hard-to-handle (and high percentage of) refractory epilepsy patients, that have presented an unresolved challenge to Neurology and Psychiatry and where the psychoanalytic clinic has the knowledge to contribute.

Mammalophilic feeding behaviour of Culex quinquefasciatus mosquitoes collected in the cities of Chetumal and Cancun, Yucatán Peninsula, Mexico.

OBJECTIVE: The studie describes the blood-feeding behaviour of mosquitoes in Mexico, to understand host-vector relationships and dynamics of disease transmission. METHODS: From September 2012 to November 2012 and in November 2013, 911 blood-fed Cx. quinquefasciatus mosquitoes were collected with aspirators inside houses in Chetumal and Cancun. Blood meals were analysed by PCR and subsequent Sanger sequencing of the cytochrome b gene. RESULTS: 93.3% of mosquitoes fed on mammals, 6.5% on birds and 0.2% on reptiles. The most frequent vertebrate hosts were humans (65.4%), dogs (23.2%), chicken (5.4%), cattle (2.2%) and cats (1.8%). CONCLUSIONS: Cx. quinquefasciatus most frequently fed on humans and dogs in both studied cities, which is in contrast to a previous study that demonstrated lower prevalence of mammalian blood in engorged Cx. quinquefasciatus.

Antimicrobial Effect of Lactobacillus reuteri on Cariogenic Bacteria Streptococcus gordonii, Streptococcus mutans, and Periodontal Diseases Actinomyces naeslundii and Tannerella forsythia.

Lactic acid bacteria (LAB) are well known for their beneficial effects on human health in the intestine and immune system; however, there are few studies on the impact they can generate in oral health. The aim of this study was to test and compare in vitro antimicrobial activity of L. reuteri on pathogenic bacteria involved in the formation of dental caries: S. mutans, S. gordonii, and periodontal disease: A. naeslundii and T. forsythia. Also, we determined the growth kinetics of each bacterium involved in this study. Before determining the antimicrobial action of L. reuteri on cariogenic bacteria and periodontal disease, the behavior and cell development time of each pathogenic bacterium were studied. Once the conditions for good cell growth of each of selected pathogens were established according to their metabolic requirements, maximum exponential growth was determined, this being the reference point for analyzing the development or inhibition by LAB using the Kirby Bauer method. Chlorhexidine 0.12% was positive control. L. reuteri was shown to have an inhibitory effect against S. mutans, followed by T. forsythia and S. gordonii, and a less significant effect against A. naeslundii. Regarding the effect shown by L. reuteri on the two major pathogens, we consider its potential use as a possible functional food in the prevention or treatment of oral diseases.

Lack of IgG antibody seropositivity to Borrelia burgdorferi in patients with Parry-Romberg syndrome and linear morphea en coup de sabre in Mexico.

BACKGROUND: Progressive hemifacial atrophy or Parry-Romberg Syndrome (PRS) is a rare, acquired, progressive dysplasia of subcutaneous tissue and bone characterized by unilateral facial involvement. Its etiology is unknown, but theories about its pathogenesis include infectious, degenerative, autoimmune, and traumatic causes among others. The causal relationship of PRS and linear morphea en coup de sabre (LMCS) with Borrelia burgdorferi infection remains controversial. Our goal was to serologically determine anti-B. burgdorferi antibodies in patients diagnosed with PRS and LMCS to establish a possible association as a causative agent. METHODS: We conducted a serology study with patients belonging to a group of 21 individuals diagnosed with PRS, six with LMCS, and 21 matched controls. Anti-Borrelia IgG antibodies were determined by ELISA. A descriptive statistical analysis and Fischer's exact test were done. RESULTS: In serological tests, only two cases had borderline values and were further analyzed by Western blot with non-confirmatory results. For both the PRS and LMCS group, the association test was not significant, suggesting a lack of association between PRS or LMCS and the presence of anti-Borrelia antibodies. CONCLUSION: In Mexico there are no previous studies on Borrelia infection and its relationship between PRS or LMCS. Our result showed a lack of association of either clinical entities with anti-Borrelia-antibodies. Former reports of this association may suggest coincidental findings without causal relationship.

Prenatal HIV testing in the US-Mexico border region, 2005: the Brownsville-Matamoros Sister City Project for Women's Health.

INTRODUCTION: Routine prenatal human immunodeficiency virus (HIV) screening provides a critical opportunity to diagnose HIV infection, begin chronic care, and prevent mother-to-child transmission. However, little is known about the prevalence of prenatal HIV testing in the US-Mexico border region. We explored the correlation between prenatal HIV testing and sociodemographic, health behavior, and health exposure characteristics. METHODS: The study sample consisted of women who delivered live infants in 2005 in hospitals with more than 100 deliveries per year and resided in Matamoros, Tamaulipas, Mexico (n = 489), or Cameron County, Texas (n = 458). We examined univariate and bivariate distributions of HIV testing in Matamoros and Cameron County and quantified the difference in odds of HIV testing by using logistic regression. RESULTS: The prevalence of prenatal HIV testing varied by place of residence--57.6% in Matamoros and 94.8% in Cameron County. Women in Cameron County were significantly more likely than those in Matamoros to be tested. Marital status, education, knowledge of methods to prevent HIV transmission (adult-to-adult), discussion of HIV screening with a health care professional during prenatal care, and previous HIV testing were significantly associated with prenatal HIV testing in Matamoros, although only the latter 2 variables were significant in Cameron County. CONCLUSION: Although national policies in both the United States and Mexico recommend prenatal testing for HIV, a greater proportion of women in Cameron County were tested, compared with women in Matamoros. Efforts between Matamoros and Cameron County to improve HIV testing during pregnancy in the border region should consider correlates for testing in each community.

[Profile of sexual behavior in 12- to 19-year-old Mexican adolescents. Results of ENSA 2000]. / Perfil del comportamiento sexual en adolescentes mexicanos de 12 a 19 años de edad. Resultados de la ENSA 2000.

OBJECTIVE: To describe traits associated with sexual behaviors in Mexican adolescents, their knowledge about contraception, and factors associated with pregnancy and utilization of contraceptives during first sexual intercourse. MATERIAL AND METHODS: Data from the Mexican National Health Survey 2000 (ENSA 2000) were analyzed. This study, conducted between September 1999 and March 2000, was a complex survey with a probabilistic, stratified, and cluster sampling design. The sample population included 15 241 adolescents 12 to 19 years of age. Data analysis included descriptive statistics and a chi-squared test for differences of proportions; also, logistic regression was used to obtain odds ratios. RESULTS: A total of 69.2% adolescents reported knowledge of at least one contraception method; 16.4% of subjects reported having had sexual intercourse. Males initiated sexual intercourse earlier than females and only 37% of all adolescents utilized contraceptives during their first sexual intercourse. Logistic regression analysis showed that being male, having a higher education, having knowledge of at least one contraception method, and having initiated sexual intercourse at an older age, were factors associated with utilization of a contraception method in their first sexual intercourse. A total of 55.7% of sexually active female adolescents had been pregnant. Pregnancy among adolescents was associated with low educational level, sexual activity at early age, and to have sometime lived in free union. CONCLUSIONS: The majority of sexually active adolescents did not use contraception during their first sexual intercourse, rendering them at risk of unwanted pregnancies.

Perfil del comportamiento sexual en adolescentes mexicanos de 12 a 19 años de edad: resultados de la ENSA 2000 / Profile of sexual behavior in 12 to 19 year-old Mexican adolescents: results of ENSA 2000

OBJETIVO: Describir las características del comportamiento sexual de los adolescentes mexicanos, su grado de conocimiento sobre anticoncepción, las variables que se relacionan con la utilización de anticonceptivos en la primera relación sexual y las que se asocian con el embarazo. MATERIAL Y MÉTODOS: Se analizó la base de datos de adolescentes de la Encuesta Nacional de Salud 2000, realizada en septiembre de 1999 a marzo de 2000, la cual tuvo un diseño complejo al ser probabilístico, polietápico, estratificado y por conglomerados. La muestra incluyó a adolescentes de entre 12 a 19 años de edad (n=15 241). Se hizo un análisis descriptivo, se aplicó la prueba ji cuadrada (Wald) para evaluar diferencias de proporciones, y se construyeron dos modelos de regresión logística para obtener razones de momios. RESULTADOS: El 69.2 por ciento de los adolescentes refirió conocer al menos un método de control de la fecundidad. El 16.4 por ciento mencionó haber tenido relaciones sexuales, y los hombres iniciaron la actividad sexual antes que las mujeres; es importante mencionar que tan sólo 37 por ciento de los adolescentes usaron algún método anticonceptivo en la primera relación sexual. El análisis de regresión logística mostró que los adolescentes del sexo masculino, los de mayor escolaridad, quienes poseían información de algún método anticonceptivo y aquellos que inician esta actividad a una edad mayor tuvieron más probabilidad de usar anticonceptivos en su primera relación sexual. El 55.7 por ciento de las mujeres que mencionaron haber iniciado actividad sexual han estado embarazadas. El embarazo en las adolescentes se asoció significativamente con un nivel bajo de escolaridad, con iniciar su vida sexual a edades tempranas y con el hecho de haber estado alguna vez unidas. Conclusiones. En general, la población adolescente que ha tenido relaciones sexuales no utilizó métodos anticonceptivos durante su primera relación, lo cual incrementa la posibilidad de embarazos.

Effect of oral chronic intoxication with sodium arsenite on murine giardiasis.

Chronic exposure to toxicants alters immune function that can affect the ability of the host to mount a response to infection. Giardiasis is a gastrointestinal disease in which subtle alteration in immunity of the host can transform the normal acute infection into a chronic one. In this work we used a murine giardiasis model to evaluate the effect of chronic oral intoxication with sodium arsenite on the characteristics of giardiasis. BALB/c mice were intoxicated during 45 days with water containing 50, 125 or 250 microg/mL sodium arsenite. Each group was then inoculated with G. muris cysts. Cysts excreted in the feces were isolated and quantified. The toxic effect of arsenic on intestinal trophozoites was evaluated using G. lamblia trophozoites cultured in vitro with different arsenic concentrations, corresponding to equivalent concentrations of arsenic found in the gut lumen of intoxicated mice. Mice intoxicated with 125 and 250 microg/mL of sodium arsenite and infected with G. muris cysts displayed a shorter period of cysts excretion and were resistant to secondary infection with the parasite. In vitro studies showed that G. lamblia trophozoites were able to grow in presence of high sodium arsenite concentrations, suggesting the absence of a direct toxic effect on the parasite in the gut. Since a longer period of Giardia cysts excretion is associated with suppression of the immune system, the earlier clearance of primary G. muris infection in intoxicated mice suggests the induction of an immune modification that leads to an improved ability of mice to overcome the infection.

Alteraciones cromosómicas secundarias en pacientes con leucemia mieloide crónica, en un hospital de referencia del noreste de México / Secondary Chromosomic Changes in Patients with Myeloid Leukemia in a Reference Hospital in Northeastern Mexico

Introducción: la caracterización del perfil citogenético que presenta una determinada fase de la leucemia mieloide crónica (LMC), está ofreciendo nuevas direcciones para la investigación de la etiología a nivel molecular. En México no existen datos de la descripción cromosómica de esta enfermedad, por lo que el objetivo del presente estudio fue determinar las alteraciones cromosómicas de 56 pacientes con LMC. Diseño: estudio transversal (diagnóstico y estadio). Material y métodos: las muestras de médula ósea de 56 pacientes con LMC en diferentes etapas, fueron sometidas a estudios citogenéticos mediante técnicas de bandeo G e hibridación in situ fluorescente (FISH), con sonda específica para cromosoma Filadelfia (Ph). Resultados: 19% (6/31) de los pacientes en etapa crónica mostró alteraciones cromosómicas secundarias, en contraste con 60% (15/25) observado en aquellos pacientes en etapa acelerada. Las alteraciones cromosómicas secundarias más frecuentes fueron: las trisomías 8 y 19, cromosoma Ph extra e isocromosoma de brazos largos del cromosoma 17. Conclusión: este es el primer trabajo que determina alteraciones cromosómicas secundarias en pacientes mestizos mexicanos con LMC, cuyas frecuencias están de acuerdo con lo reportado para otras poblaciones a nivel mundial.

Introduction: Our aim was to characterize the cytogenetic profile that displays a certain phase of chronic myelogenous leukemia (CML), offering new directions for investigation of the etiology to the molecular level. In Mexico, data does not exist in this regard; thus, the objective of the present study was to determine cytogenetic alterations in 56 Mestizo Mexican patients with LMC. Design: Cross-sectional study (diagnosis and stage) was carried out. Materials and Methods: samples of bone marrow of 56 patients with CML in different phases were analyzed using G banding and fluorescence in situ hybridization (FISH) with DNA probes for Philadelphia chromosome (Ph). Results: 19% of patients in chronic stage showed secondary chromosomal alterations in contrast with an observed 60% in patients in accelerated stage. Most frequent alterations included trisomy 8 and 19, extra Ph chromosome, and isochromosome of thell. Conclusions: We believe this to be the first work that determines secondary chromosomal alterations in Mexican racially mixed patients with LMC. These are in agreement with those reported for other populations at the worldwide level.

Evaluation of the mutagenic and cytotoxic effects of mercurous chloride by the micronuclei technique in golden Syrian hamsters.

The aims of this study were to evaluate the mutagenic and cytotoxic activity of mercurous chloride by the micronucleus technique in vivo on the bone marrow of golden Syrian hamsters after a single i.p. drug administration. Forty male golden Syrian hamsters were classified into eight groups: negative control, positive control and six groups treated with different doses of mercurous chloride (1.25, 2.5, 5, 10, 20 and 40 mg/kg). The negative control was injected with physiological saline i.p. and the positive control with cyclophosphamide at a dose of 80 mg/kg i.p. With respect to mutagenic effect, the average number of micronucleated polychromatic erythrocytes (MPE) in hamsters treated with different doses of mercurous chloride was not significant compared with the negative control. With respect to cytotoxic effect, the average polychromatic erythrocyte/red blood cell ratio showed a significant decrease when the doses were higher than the 2.5 mg/kg dose compared with the negative control. In conclusion, this preliminary study shows a cytotoxic effect but not a mutagenic effect of calomel in vivo at one time point (24 h).