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Biomedical subjects

M C Ramos

Publications and source records attributed to M C Ramos.

At least 19 recordsLinked to original sources
PubMed2005

Metals in vineyard soils of the Penedès area (NE Spain) after compost application.

The application of organic wastes to improve soil physical characteristics in mechanized vineyards planted after land levelling is becoming a common practice in Mediterranean areas. It may be useful as an additional source of organic matter and nutrients, but these wastes could also have negative effects due to their metal content. The aim of the study was to evaluate the influence of compost application on soil metal contents in mechanized vineyard soils of the Spanish Mediterranean area, where this practice is repeated every three years. The study was carried out in a ten-year-old vineyard where the main soil type is Typic Calcixerept. Composted cattle manure was applied in alternate rows, at a rate of 40 Mgha(-1) dry-weight. Nine sampling points were located along the slopes of two plots: a levelled plot prepared for mechanization with large soil disturbance movements within the plot, and a plot of undisturbed soil. At each location, soil samples were taken in both treated and untreated soils. Total concentrations (digestion with aqua regia) and the extractable DTPA (Diethylene-triaminepentacetic)-CaCl2-TEA (Triethanolamine) fractions of Cu, Zn and Mn were analyzed in each sample. For Cu and Zn, the initial concentration was higher in the undisturbed plot. In both cases, total Cu and total Zn were positively affected by manure input and the concentration in treated soils was significantly higher than in untreated soil. For Mn, the initial concentration was higher in disturbed soils than in undisturbed ones, and although in both scenarios the concentrations increased with manure, no significant differences were found between treated and untreated soils. The extractable fraction also increased in treated versus untreated soils, although for Cu and Mn the extractable/total metal ratio was similar in treated and untreated soils. After one compost application, total metal contents increased significantly, particularly for Zn. Most of those metals are accumulated in the soil, due to the soil characteristics.

Agriculture↗
PubMed2005

Effects of cattle manure on erosion rates and runoff water pollution by faecal coliforms.

The large quantities of slurry and manure that are produced annually in many areas in which cattle are raised could be an important source of organic matter and nutrients for agriculture. However, the benefits of waste recycling may be partially offset by the risk of water pollution associated with runoff from the fields to which slurry or manure has been applied. In this paper, the effects of cattle manure application on soil erosion rates and runoff and on surface water pollution by faecal coliforms are analysed. Rainfall simulations at a rate of 70 mm h(-1) were conducted in a sandy loam soil packed into soil flumes (2.5m long x 1m wide) at a bulk density of 1400 kg m(-3), with and without cattle slurry manure applied on the surface. For each simulation, sediment and runoff rates were analysed and in those simulations with applied slurry, presumptive faecal coliform (PFC) concentrations in the runoff were evaluated. The application of slurry on the soil surface appeared to have a protective effect on the soils, reducing soil detachment by up to 70% but increasing runoff volume by up to 30%. This practice implies an important source of pollution for surface waters especially if rainfall takes place within a short period after application. The concentrations of micro-organisms (presumptive faecal coliforms (PFCs)) found in water runoff ranged from 1.9 x 10(4) to 1.1 x 10(6) PFC 100mL(-1), depending on the initial concentration in the slurry, and they were particularly high during the first phases of the rainfall event. The result indicates a strong relationship between the faecal coliforms transported by runoff and the organic matter in the sediment.

Animals↗
PubMed2005

Prevalence of katG Ser315 substitution and rpoB mutations in isoniazid-resistant Mycobacterium tuberculosis isolates from Brazil.

SETTING: Four hundred and sixty-eight isoniazid (INH) resistant Mycobacterium tuberculosis isolates recovered from a selected Brazilian population. OBJECTIVE: To check for susceptibility to other chemotherapeutic drugs used in TB treatment, and to ascertain mutations involved in INH and rifampicin (RMP) resistance. DESIGN: Antimicrobial susceptibility to RMP, streptomycin and ethambutol (EMB) was evaluated by the resistance ratio method and pyrazinamide (PZA) by activity assay. Single strand conformation polymorphism (SSCP) and sequence analysis were performed in samples from this panel to confirm mutations in codon 315 of the katG and in a 69-bp region of the rpoB gene. RESULTS: Combined resistance to INH+RMP, INH+ PZA, INH+EMB, and INH+RMP+PZA was shown in respectively 272 (58.1%), 126 (26.9%), 47 (10%), 116 (24.8%) isolates. No katG mutation was found in 19 (39.6%) of 48 strains tested. Ser315Thr substitution was found in 29 (60.4%). All RMP-resistant strains tested (n = 25) showed rpoB mutations. S531L substitution was found in 15 (60%). CONCLUSION: INH-resistant strains isolated from selected Brazilian populations frequently show resistance to other first-line anti-tuberculosis drugs. rpoB mutation was responsible for RMP resistance in all strains. Among INHr strains, katG mutations were shown in only 60.4%. Genetic approaches targeting the rpoB gene but not the katG gene have a high sensitivity to detect resistance among Brazilian M. tuberculosis strains.

Antitubercular Agents↗
PubMed2003

IS1245 restriction fragment length polymorphism typing of Mycobacterium avium from patients admitted to a reference hospital in Campinas, Brazil.

Mycobacterium avium is an important pathogen among immunodeficient patients, especially patients with AIDS. The natural history of this disease is unclear. Several environmental sources have been implicated as the origin of this infection. Polyclonal infection with this species is observed, challenging the understanding of its pathogenesis and treatment. In the present study 45 M. avium strains were recovered from 39 patients admitted to a reference hospital between 1996 and 1998. Species identification was performed using a species-specific nucleic acid hybridization test (AccuProbe) from Gen-Probe. Strains were genotyped using IS1245 restriction fragment length polymorphism typing. Blood was the main source of the organism. In one patient with disseminated disease, M. avium could be recovered more than once from potentially sterile sites. Strains isolated from this patient had different genotypes, indicating that the infection was polyclonal. Four patient clones were characterized in this population, the largest clone being detected in eight patients. This finding points to a common-source transmission of the organism.

AIDS-Related Opportunistic Infections↗
PubMed2002

PCR-based ribotyping of Staphylococcus aureus.

Genotyping techniques are valuable tools for the epidemiologic study of Staphylococcus aureus infections in the hospital setting. Pulsed-field gel electrophoresis (PFGE) is the current method of choice for S. aureus strain typing. However, the method is laborious and requires expensive equipment. In the present study, we evaluated the natural polymorphism of the genomic 16S-23S rRNA region for genotyping purpose, by PCR-based ribotyping. Three primer pairs were tested to determine the size of amplicons produced and to obtain better discrimination with agar gel electrophoresis and ethidium bromide staining. The resolution of the typing system was determined using sets of bacteria obtained from clinical specimens from a large tertiary care hospital. These included DNA from three samples obtained from a bacteremic patient, six strains with known and diverse PGFE patterns, and 88 strains collected over a 3-month period in the same hospital. Amplification patterns obtained from samples from the same patient were identical, and PFGE from samples known to be different produced three genotypes. Amplification of DNA from 61 methicillin-resistant isolates produced only one pattern. Methicillin-sensitive strains yielded a diversity of patterns, pointing to a true polyclonal distribution throughout the hospital (22 unique patterns from 27 strains). Computer-based software can be used to differentiate among identifiable strains, given the low number of bands and good characterization of PCR products. PCR-based ribotyping can be a useful technique for genotyping methicillin-sensitive S. aureus strains, but is of limited value for methicillin-resistant strains.

Genotype↗
PubMed2001

Spotted fever in Brazil: a seroepidemiological study and description of clinical cases in an endemic area in the state of São Paulo.

During 1985-1995, illnesses clinically and epidemiologically compatible with Brazilian spotted fever were identified in 17 patients in the county of Pedreira, in the state of São Paulo, Brazil. Spotted-fever group rickettsial infection was confirmed by serology and/or immunostaining of tissues in 10 of these patients. Immunostaining confirmed infection in a 37-year-old pregnant patient, although rickettsial antigens were not demonstrable in the tissues of the fetus. A serosurvey was conducted in four localities in the county to determine the prevalence of subclinical or asymptomatic infections with spotted fever group rickettsiae. Five hundred and twenty-five blood samples were tested by an indirect immunofluorescence assay for antibodies reactive with Rickettsia rickettsii. Twenty-two (4.2%) of these samples demonstrated titers > or = 1:64. The results indicate that Brazilian spotted fever is endemic within this region of Brazil.

Adult↗
PubMed2000

Alzheimer's risk associated with human apolipoprotein E, alpha-2 macroglobulin and lipoprotein receptor related protein polymorphisms: absence of genetic interactions, and modulation by gender.

Apolipoprotein E (apoE), the lipoprotein receptor related protein (LRP) and alpha-2 macroglobulin (alpha2M) have been proposed as a functional complex involved in amyloid clearance, a crucial event for Alzheimer's disease development. In this work, we present an epidemiological approach aimed to study the interactions among these genes, age and gender. This approach did not reveal significant associations between the genes; however, the present study indicated that the risk associated with APOE promoter and LRP gene polymorphisms is modulated by gender.

Age Factors↗
PubMed1999

Widespread occurrence of the homologues of the early nodulin (ENOD) genes in Oryza species and related grasses.

Eighty accessions representing 23 species from the genus Oryza were examined for the presence of homologues of early nodulin (ENOD) genes. Southern analyses indicated a widespread distribution of homologues of ENOD genes across all the genomes of rice as well as other monocots. The degree of cross-hybridization of the legume ENOD genes with sequences in the genomes of various species, as revealed by hybridization differentials measured in terms of signal intensities, however, suggests that the homologues of ENOD genes are conserved to varied extents in different Oryza species. The presence of homologues of ENOD genes in a wide variety of plant species denotes that the biological functions of early nodulins may be diverse, and not restricted to nodule organogenesis alone. The fact that ENOD gene homologues exist widely both in dicots and monocots provides evidence that these homologues have arisen from a common ancestral plant.

DNA, Plant↗
PubMed1999

Usefulness of spoligotyping in molecular epidemiology of Mycobacterium bovis-related infections in South America.

Two hundred twenty-four Mycobacterium bovis isolates, mainly from South American countries, were typed by spoligotyping, and 41 different spoligotypes were identified. A total of 202 M. bovis isolates (90%) were grouped into 19 different clusters. The largest cluster contained 96 isolates (42.8%) on the basis of the most frequently observed spoligotype, spoligotype 34. Nineteen M. bovis isolates from humans in Argentina had spoligotypes and polymorphic GC-rich repetitive sequence (PGRS) types that represented the most common types found among isolates from cattle. All five isolates from Uruguay and three of the six isolates from Paraguay had spoligotypes that were also detected for isolates from Argentina. The spoligotypes of isolates from Brazil, Costa Rica, and Mexico and of some of the isolates from Paraguay could not be found in Argentina. A total of 154 M. bovis isolates were selected in order to compare the discriminative power of spoligotyping and restriction fragment length polymorphism (RFLP) analysis with direct repeat (DR) and PGRS probes. By spoligotyping, 31 different types were found, while AluI-digested DR probe-associated RFLP analysis identified 42 types, and RFLP analysis with the PGRS probe also detected 42 types; these were partly independent of the DR types. By combining the results obtained by spoligotyping and by RFLP analysis with the DR and PGRS probes, 88 different types were obtained. Although the differentiation of M. bovis by spoligotyping was less discriminatory than differentiation by RFLP analysis with the DR and PGRS probes, spoligotyping is easier to perform and its results are easier to interpret. Therefore, for the purpose of typing of M. bovis isolates, spoligotyping could be performed first and the isolates could be grouped into clusters and then analyzed by RFLP analysis with the DR and PGRS probes.

Animals↗
PubMed1998

Validation of national algorithms for the diagnosis of sexually transmitted diseases in Brazil: results from a multicentre study.

OBJECTIVE: To validate STD flow charts for the management of genital discharge and genital ulcer currently recommended by the National STD Control Programme in Brazil. METHODS: A study was conducted in five Brazilian STD clinics from January to June 1995. After an interview, a clinical examination was performed by a physician, who recorded a presumptive diagnosis, based on his/her clinical experience. This diagnosis was compared with a gold standard laboratory diagnosis in order to calculate sensitivity, specificity, and positive predictive value of the clinical diagnosis. The validity of the simulated national flow charts was assessed using the same method. RESULTS: A total of 607 men and 348 women participated in the study. Gonorrhoea was the aetiology most frequently detected in men with urethral discharge. The sensitivity of the clinical diagnosis was far lower than the sensitivity fo the national flow chart, using the syndromic approach, for both gonococcal and chlamydial urethritis. Adding a simple laboratory test (Gram stain) to the national flow chart increased the specificity and positive predictive value for gonorrhoea. Among the women with vaginal discharge, a cervical infection was detected in 17%, a vaginal infection in 74%, and mixed infection in 9%. The sensitivity of the diagnosis for cervical infection increased from 16% (clinical aetiological approach) to 54% (when adding a syndromic approach) and to 68% when adding a risk assessment, as in the national flow charts. The cure or improved rate of genital ulcers was 96% after 1 week. CONCLUSIONS: The results of the study will help to convince policy makers and those involved in training healthcare workers in Brazil of the public health advantages of the syndromic approach, as an essential part of STD/HIV control activities.

Adult↗
PubMed1998

[The postantibiotic effect of amoxicillin/clavulanic acid on Streptococcus pneumoniae strains of different serotypes and penicillin sensitivity].

Amoxicillin and clavulanic acid, combined in a 4:1 ratio, caused a significant (longer than 0.5 hours) postantibiotic effect (PAE) for the S. pneumoniae stains tested. These strains were from a different serotype (3, 6 and 9) and also had different susceptibility to penicillin. The duration of the PAE depended both on the strain and the amoxicillin/clavulanic acid concentration used. It is significant that for the serotype 9 strain, which was both penicillin and amoxicillin resistant, the duration of the PAE was between 1.5 and 2.2 hours. These results agree with those observed by other authors as to the effectiveness of amoxicillin/clavulanic acid against S.pneumoniae.

Amoxicillin-Potassium Clavulanate Combination↗
PubMed1997

The development and implementation of an integrated multidisciplinary clinical pathway.

Clinical pathways, linear time-related representations of patient care processes, are widely encouraged as a mechanism to outline efficient, cost-effective, multidisciplinary care. The translation of pathways from concept to reality is, however, predictably difficult. All caregivers are dedicated to a common goal, but organizational, personal, and professional perspectives are barriers to development of a common tool. Moreover, the building process requires the discovery, articulation, and communication of previously tacit patient care processes. Although no prescription can work for all pathway development, some strategies can help ensure the best possible chance of pathway success. Participants must recognize that between-patient variability can be expected to decrease with pathway implementation, and educational processes must support that aim. "Stakeholder groups" must be identified and their investment must be assessed, with careful attention paid to acquiring the unconditional support of institutional leadership. Planning of precise building, implementation, and piloting processes, with provision for facilitation of building and implementation processes, is critical. Those charged with pathway development must commit to the establishment and explication of clear goals (economic and quality outcomes) and to careful integration of the pathway with planned and existing continuous quality improvement processes. These strategies are illustrated with actual experiences in implementing cystectomy and pressure ulcer pathways in one academic medical center.

Communication↗
PubMed1996

Ampicillin-sulbactam is effective in prevention and therapy of experimental endocarditis caused by beta-lactamase-producing coagulase-negative staphylococci.

Optimal strategies for the prophylaxis and therapy of endocarditis caused by oxacillin-resistant, coagulase-negative staphylococci in patients with native or prosthetic valvular heart disease are not well defined. We compared the in vivo efficacies of ampicillin-sulbactam-based regimens with those of vancomycin-based oxacillin-resistant, beta-lactamase-producing coagulase-negative staphylococcal isolate (Staphylococcus haemolyticus SE220). Ampicillin-sulbactam (100 and 20 mg/kg of body weight, respectively, given intramuscularly in a two-dose regimen) was equivalent to vancomycin (30 mg/kg given intravenously in a two-dose regimen) in its prophylactic efficacy against the coagulase-negative staphylococcal strain (93 and 80%, respectively). The combination of ampicillin-sulbactam plus either rifampin or vancomycin did not enhance the prophylactic efficacy compared with that of ampicillin-sulbactam or vancomycin alone. In the therapy of established aortic valve endocarditis in rabbits caused by this same coagulase-negative staphylococcal strain, animals received 7-day ampicillin-sulbactam-based or vancomycin-based regimens with or without rifampin. All treatment regimens were effective at lowering intravegetation coagulase-negative staphylococcal densities and rendering vegetations culture negative compared with the coagulase-negative staphylococcal densities and vegetations of untreated controls, with ampicillin-sulbactam in combination with rifampin or vancomycin being the most active regimen. However, only the regimen of ampicillin-sulbactam in combination with vancomycin effectively prevented relapse of endocarditis posttherapy after a 5-day antibiotic-free period. For animals receiving rifampin-containing regimens, relapses of endocarditis were associated with the in vivo development of rifampin resistance among coagulase-negative staphylococcal isolates in the vegetation. Ampicillin-sulbactam was highly effective in the prevention of experimental endocarditis caused by a beta-lactamase-producing, oxacillin-resistant coagulase-negative staphylococcal strain. Ampicillin-sulbactam was also efficacious for the therapy of coagulase-negative staphylococcal endocarditis, especially when it was combined with vancomycin to prevent posttherapeutic relapses.

Ampicillin↗
PubMed1996

Proliferating cell nuclear antigen (PCNA) as a marker of dysplasia in oral mucosa.

The development of head and neck cancer has been proposed to be a multistep process, with accumulation of genetic and phenotypic alterations resulting from carcinogen exposure. Proliferating cell nuclear antigen (PCNA), also called cyclin, is a 36-KD auxiliary protein of DNA polymerase-delta, that has been found to be a useful marker in immunocytochemical studies of cell proliferation because its expression correlates with the proliferative state of the cell. PCNA expression was analyzed in 10 samples of normal mucosa, 23 benign oral lesions (18 hyperplasia and 5 oral lichen plani), 10 oral lesions with epithelial dysplasia, and 10 dysplastic epithelia adjacent to tumors. Immunocytochemical stained sections were scored for the presence or absence of suprabasal PCNA positivity regardless of location. The results indicate that the PCNA expression in the suprabasal layers increased with the degree of epithelia dysplasia and in the samples of histological dysplastic epithelium adjacent to the tumors, while the percentage of suprabasal PCNA expression was insignificant in the samples of normal oral mucosa and benign oral lesions. The authors conclude that suprabasal PCNA expression could be a marker of dysplasia in oral mucosa, indicating a special proliferative cellular state in those lesions.

Biomarkers, Tumor↗
PubMed1993

Mitral valve prolapse and its effects: a programme of inquiry within Orem's Self-Care Deficit Theory of Nursing.

The optimum growth and scientific progress of nursing knowledge during the next century will depend upon the development and execution of focused programmes of clinical and theoretical research. The planning and design of such programmes must originate with the clear definition of nursing research questions. Nesting such questions within established theoretical frameworks provides a nursing context, lends precise language and suggests relevant variables for study. The development of a sequence of related studies exploring and describing the self-care needs of people with symptomatic mitral valve prolapse illustrates one such systematic research programme. Orem's Self-Care Deficit Theory of Nursing was used as a theoretical framework for four completed studies which describe one population's need for nursing assistance. The evolving nature of the research programme and plans for future research are discussed.

Adolescent↗