Impact of the induction phase chemotherapy on cytokines and oxidative markers in peripheral and bone marrow plasma of children with acute lymphocytic leukemia.

B-cell acute lymphocytic leukemia (B-ALL) is the main neoplasia affecting children worldwide, in which cytotoxic chemotherapy remains the main treatment modality. In this study, we analyzed the profile of inflammatory markers concerning oxidative stress and cytokines in 17 B-ALL patients. Peripheral blood (PB) and bone marrow (BM) samples were collected and evaluated for the pro-oxidative status (nitric oxide products-NOx and hydroperoxides), antioxidants (sulfhydryl groups-SH and total radical-trapping antioxidant parameter-TRAP), and cytokines (TNF-α, IFN-γ), at diagnosis (D0) to and the end of the induction phase (D28). At D28, hydroperoxides were higher in PB, concomitant to TNF-α levels. INF-γ was increased in the BM at D28. Hydroperoxides were higher in patients presenting malignant cells in BM and/or PB after treatment, a condition named minimal residual disease (MRD) when compared to those without MRD at D28. These findings suggest that oxidative stress and cytokines vary across the B-ALL induction phase, and lipid peroxidation is a potential marker associated with MRD status.

Characterisation of Mannheimia spp. strains isolated from bovine nasal exudate and factors associated to isolates, in dairy farms in the Central Valley of Mexico.

Mannheimia spp. strains obtained from bovine nasal exudates of either clinically healthy or clinically affected by respiratory tract disease animals were isolated and characterised to estimate the prevalence of isolated serotypes in dairy farms in Mexico, by means of a trans-sectional descriptive study. Strains were isolated and typified through biochemical and immunological tests. chi(2) or Fisher statistical tests were applied, as well as odds ratio calculation and logistic regression analysis to evaluate the association and effect of some variables on Mannheimia spp. isolation. The apparent prevalence rates of Mannheimia haemolytica was significantly higher in diseased bovines (OR = 1.94; p < 0.05), as well as in bovines younger than 1 year of age (OR = 23.98; p < 0.05), and in bovines not vaccinated against bovine pasteurellosis (OR = 1.52; p < 0.05). Age was the variable that remained in the logistic regression model. Serotype A1 showed the highest prevalence, even when most isolates were not-typable. Bovines younger than one year of age and those with disease were the groups with the highest frequency of M. haemolytica and Mannheimia glucosida isolates.

Immunohistochemical detection of antigens of distemper, adenovirus and parainfluenza viruses in domestic dogs with pneumonia.

The lungs of 35 dogs that died in Mexico from acute or subacute pneumonia were examined immunohistochemically for canine distemper virus (CDV), canine adenovirus (CAV) and canine parainfluenza virus (CpiV), to determine their frequency and occurrence and possible associations. CDV was identified in 27 (77%) cases, CAV in 20 (57%) and CpiV in 18 (51%). The most frequent dual association was that between CDV and CpiV (five cases; 14%). All three viruses, however, were identified in the same lung in 10 cases. Immunolabelling occurred in alveolar macrophages, monocytes, pneumocytes, epithelial cells and syncytial cells. It was concluded that immunohistochemistry is a useful diagnostic tool in canine respiratory disease to complement histopathological examination.

Haplotype study of microsatellites flanking the t(15;17) breakpoint in acute promyelocytic leukemia patients from North Portugal.

A higher frequency of acute promyelocytic leukemia (APL) has been noted in countries of Southern Europe and among 'Latino' patients of the United States with acute myeloid leukemia (AML). In order to discover whether there is any genetic predisposition to the disease, we analyzed microsatellites flanking PML and RARalpha genes in 29 t(15;17) APL patients from North Portugal and compared them with a control group of 123 healthy individuals. Fluorescent PCR products were analyzed using an automated capillary electrophoresis system and allele and haplotype frequencies of the two populations were determined. No significant differences were found, suggesting the same genetic origin of patients and healthy individuals. As suggested by the four microsatellites screened, MSI (microsatellite instability) does not explain the increased incidence of t(15;17) APL in this Portuguese population. These results intend to be a new approach to the study of APL, reflecting the particularity of the disease.

Seroprevalence study of bovine neosporosis in Mexico.

An indirect enzyme-linked immunosorbent assay was used to obtain epidemiologic information on bovine neosporosis in dairy herds of the Mexican central plateau. Sera were collected from 1,003 cows from 50 dairy herds. Forty-three herds (group A) had been experiencing a high abortion rate. The abortion rates for the remaining 7 herds (group B) were within normal limits for Mexico. Five-hundred sixty-one (56%) of the 1,003 sera were positive. The seroprevalence of Neospora caninum antibodies was 72% (95% CI = 68-75%) in group A and 36% (95% CI = 31-40%) in group B. These results clearly show that infection with N. caninum is widespread in Mexican dairy herds, as indicated by seropositive cows in group A and group B herds at the time of the sample collection.

Neosporosis in Mexican dairy herds: lesions and immunohistochemical detection of Neospora caninum in fetuses.

Of 211 aborted bovine fetuses collected from Mexican dairy herds between January 1996 and March 1999, 73 showed microscopical lesions consistent with neosporosis. Of these 73 fetuses, 58 (79%) showed lymphocytic myocarditis, 39 (53%) showed microgliosis and multifocal necrosis in the brain, 39 (53%) showed lymphocytic hepatitis, and 19 (26%) showed lymphocytic myositis. Immunohistochemical examination of brain, myocardium and liver from 53 of the same 73 fetuses demonstrated Neospora caninum antigens in 41 (77%), of which 19 (46%) gave positive results in one of the three sites, 15 (37%) in two, and seven (17%) in three. The results indicated the presence of neosporosis in a number of the main dairy farming regions of Mexico.

Purification and characterization of an adhesin from Pasteurella haemolytica.

We purified an adhesin from Pasteurella. haemolytica by affinity chromatography using glutaraldehyde treated rabbit erythrocytes stroma. The adhesin is a protein of 68 kDa, as determined by SDS-PAGE, and the most abundant amino acids constituting this protein were Gly, Ser, Glx, and Ala, and low concentrations of Cys, Met, and Tyr residues were also found. The N-terminal sequence of the adhesin is ANEVNVYIYKQPYLI. No carbohydrate residues were detected. The adhesin agglutinated rabbit erythrocytes but when the latter were desialylated or pronase treated the agglutinating activity was abolished. The agglutinating activity of the adhesin was inhibited with N-acetyl-D-glucosamine (GlcNAc), and in a lesser degree with N-acetyl-neuraminic acid (NeuAc). GalNAc, N-glycolyl-neuraminic acid, N-deacetylated GlcNAc, or neutral sugars do not modify the activity of the adhesin. The equatorial -OH on C4 and the NH-acetylated group on C2 from GlcNAc, as well as the 4-OH and NH-acetylated group on C5 from NeuAc seem to be responsible for the interaction with the adhesin. The protein is divalent cation-dependent and thermolabile. As for the agglutinating activity, the adhesion of P.haemolytica to tracheal cell-cultures was inhibited by GlcNAc, NeuAc or the purified adhesin, strongly suggesting that the P.haemolytica adhesin plays an important role in infection.

Importancia del conocimiento de la Ciencia y Tecnología en la Educación Bioquímica y Farmacéutica / Importance of the knowledge of the science and technologic in the education biochemestry and pharmaceutical

El presente trabajo tiene como objetivo fundamental, orientar a la juventud de Bioquímica y Farmacéutica, sobre la importancia que tiene el conocimiento de la ciencia, tecnología e innovación tecnológica. Tres elementos fundamentales para el desarrollo de nuestro país y para enfrentar con solvencia, los problemas que presenta el siglo XXI. Con este propósito es necesario incluir los conceptos básicos de ciencia, tecnología e innovación tecnológica

Transplacental transfer of measles and total IgG.

This study was conducted to evaluate factors affecting the levels of total IgG (tIgG) and measles specific IgG (mIgG) in mother and cord sera, and the efficiency of transplacental transport of tIgG and mIgG. The study was conducted in four hospitals in Oporto, Portugal, where 1539 women and their newborns were enrolled. Measles IgG levels were lower among vaccinated mothers and respective cord sera than among vaccinated counterparts. Cord mIgG was strongly correlated with maternal levels in both vaccinated and unvaccinated groups. Transplacental transport efficiency (TTE) of mIgG decreased with increasing maternal levels, although almost one third of the observed effect was due to measurement error. The TTE was not affected by vaccination status. Monitoring maternal measles antibody levels and maternal vaccination status could be useful to determine when the age for measles vaccination can be reduced.

[Mechanisms of pathogenicity and adhesion in Pasteurella haemolytica]. / Mecanismos de patogenicidad y adherencia de Pasteurella haemolytica.

Pasteurella haemolytica is one of the bacteria most commonly isolated from pneumonic cases in ruminants. Some of the mechanisms and factors involved in the pathogenesis of the disease are partially documented; and the early stages of bacterial colonization have not been totally clarified. Therefore a review is presented in this paper, particularly related with the mechanisms of bacterial pathogenicity responsible of pulmonary damage to ruminants, as well as a detailed analysis of the adherence process.

Serotypes of Pasteurella multocida and Pasteurella haemolytica isolated from pneumonic lesions in cattle and sheep from México.

A total of 13,000 pairs of lungs were examined at Mexico's City abbatoir, where 8,000 corresponded to sheep and 5,000 to cattle. From those, 224 pneumonic lesions were observed, obtaining 97 positive isolates, which yielded 112 strains of Pasteurella sp. Forty isolates were identified as P. haemolytica and 72 as P. multocida. One-hundred percent of P. haemolytica belonged to biotype A. Serotypes were determined by indirect haemagglutination. P. multocida isolates were classified according to the acriflavine and hyaluronidase techniques, 61% belonged to type A, 25% to type D and 14% were untypified. Somatic serotypes were determined by gel immunodiffusion; serotype 3 was more frequent, in sheep 72% and in cattle 77%.

[Urinary tract infections. The causative agents and their sensitivities to chemotherapeutic drugs]. / Infecções do tracto urinário. Agentes e sensibilidades aos quimioterápicos.

A retrospective study was made of the requests for bacteriological examination of urine samples by the different clinical departments of Vila Nova de Famalicão District Hospital, between July/89-June/90 and July/91-June/92. We were interested in assessing the spectrum of occurring micro-organisms in urinary tract infections, their antibiotic susceptibility, especially to those more frequently used in clinical practice in this institution and their evolution in time. In conclusion, the prevalence of isolated pathogens was quite similar to the spectrum published by other authors for a hospital population. No significant variation was found in the bacterial population between the two periods analysed, if we exclude the great increase in coagulase-negative staphylococci. In terms of benefits/costs/resistance, we concluded that the best antibiotic for the beginning of therapy in this Hospital is cotrimoxazole. Good choices were also quinolones, third-generation cephalosporins or aminoglycosides, but with the disadvantages of greater cost for the first two and toxicity for the last.

[Evaluation of phagocytosis, bactericidal effect, and cytotoxicity of Pasteurella haemolytica and Pasteurella multocida in bovine alveolar macrophages]. / Evaluación de fagocitosis, efecto bactericida y citotoxicidad de Pasteurella haemolytica y Pasteurella multocida en macrofagos alveolares de bovinos.

Evaluation of phagocytosis and bactericidal effect of Pasteurella haemolytica and P. multocida was conducted on bovine alveolar macrophages freshly obtained through bronchioalveolar washings from live animals. Cytotoxic activity of these bacteria on the alveolar macrophages was evaluated through the simple visual assay in microplates, using bovine blood leukocytes as a comparative target cell. In order to evaluate phagocytosis the following variables were considered P. haemolytica and P. multocida (independently) in contact with alveolar macrophages, P. haemolytica and P. multocida in suspension as a positive control of bacterial growth, and RPMI-1640 medium alone, as a negative control of bacterial growth. To measure bactericidal capacity, bacteria were incubated with plastic adhered alveolar macrophages at 30 minutes and 3 hours intervals. Samples incubated 30 minutes were taken as phagocytosis-base readings and at the 3 h interval to evaluate bactericidal capacity of the alveolar macrophages on phagocytized bacteria. Reading of the samples of each evaluation was conducted in a spectrophotometer a 380 nm. Phagocytosis results indicated that bacterial proliferation was higher when bacteria were alone as compared when they were with alveolar macrophages (p < 0.05). Bactericidal capacity of the macrophages was efficient because bacterial numbers were higher in the first evaluation as compared to the second (p < 0.05). It was demonstrated that the cytotoxic effect of P. haemolytica was more severe on blood leukocytes as compared to alveolar macrophages (p < 0.05). There was no evidence of P. multocida cytotoxicity on the evaluated cells. With the development of this technique for the obtention of alveolar macrophages and using spectrophotometry for the phagocytosis and bactericidal effect evaluations, numerous variables and samples can be tested, such as opsonized bacteria or to measure the behaviour of alveolar macrophages infected with different agents involved in the bovine pneumonic complex.

[Bardet-Biedl syndrome: subclinical renal disorders in 2 siblings]. / Síndrome de Bardet-Biedl: alteraciones renales subclínicas en dos hermanos.

Two siblings with Bardet-Biedl's syndrome are studied, in whom renal structural and functional disorders were observed, with reduction in the ability to concentrate urine in both cases and decrease of creatinine clearance in the second case. The study of the hypophyseal function was normal.

Bacterial adhesion to mucosal surfaces with special reference to Pasteurella multocida isolates from atrophic rhinitis.

Adhesion to mucosal cells is an important virulence attribute of bacterial pathogens colonizing these sites. Bacteria of the upper respiratory system, such as members of the genus Bordetella, have well-defined adhesins. The main adhesin of B. pertussis is the filamentous hemagglutinin which can be used by other bacteria for attachment. The main adhesin of B. bronchiseptica is the bovine erythrocyte hemagglutinin. In both Bordetella species the presence of fimbriae does not appear critical to adhesion. In contrast, atrophic rhinitis (AR)-producing strains of Pasteurella multocida colonize poorly the pig's nasal mucosa. We performed an in vitro trial using newborn pigs' turbinate explants and showed that two toxigenic strains (serotype D fimbria + and serotype A fimbria -) were adherent when observed by scanning electron microscopy (SEM). Intranasal inoculation of both six week old and newborn SPF pigs with various strains of P. multocida also resulted in colonization. Adhesion was best achieved by toxigenic strains, regardless of possession of fimbria, hemagglutinin or capsular serotype. Colonization was more abundant and constant in tonsils. Nasal colonization was sporadic and sparse. Colonization of trachea and lung was only observed with serotype A strains. The results showed that toxigenic P. multocida can colonize the upper respiratory tract, especially the tonsils, of pigs.