Biomedical subjects

L Neves

Publications and source records attributed to L Neves.

13 recordsLinked to original sources

PubMed2006

Anaerobic co-digestion of coffee waste and sewage sludge.

The feasibility of the anaerobic co-digestion of coffee solid waste and sewage sludge was assessed. Five different solid wastes with different chemical properties were studied in mesophilic batch assays, providing basic data on the methane production, reduction of total and volatile solids and hydrolysis rate constant. Most of the wastes had a methane yield of 0.24-0.28 m3 CH4(STP)/kg VS(initial) and 76-89% of the theoretical methane yield was achieved. Reduction of 50-73% in total solids and 75-80% in volatile solids were obtained and the hydrolysis rate constants were in the range of 0.035-0.063 d(-1). One of the solid wastes, composed of 100% barley, achieved a methane yield of 0.02 m3 CH4(STP)/kg VS(initial), reductions of 31% in total solids, 40% in volatile solids and achieved only 11% of the theoretical methane yield. However, this waste presented the highest hydrolysis rate constant. Considering all the wastes, an inverse linear correlation was obtained between methane yield and the hydrolysis rate constant, suggesting that hydrolysis was not the limiting factor in the anaerobic biodegradability of this type of waste.

Anaerobiosis↗

PubMed2005

Serological survey of Babesia bovis and Anaplasma marginale in cattle in Tete Province, Mozambique.

A serological survey of bovine babesiosis and anaplasmosis in communal cattle was conducted in the northwestern province of Tete, Mozambique. Blood was collected from cattle ranging from 4 to 15 months old from randomly selected farms from six districts. Thirty-nine per cent of all 478 calves tested in Tete Province were seropositive to the ELISA for Babesia bovis antibodies and 63% of all calves were seropositive in the card agglutination test for Anaplasma marginale. Seroprevalence of B. bovis ranged from 22.8% in Tete City District to 48.1% in Angonia District. For A. marginale, it ranged from 34.4% in Angonia District to 87.3% in Moatize District. The dominant factor affecting seroprevalence for both haemoparasites was district and there was a trend for higher intensity of tick control to be associated with a higher seroprevalence of B. bovis and a lower seroprevalence of A. marginale. The obvious differences were the low prevalence of B. bovis in Tete City Council District and the low prevalence of A. marginale in Angonia District. The levels of exposure to B. bovis seen in our study are well below any that could be considered to be consistent with endemic stability, yet they are sufficiently high to ensure that clinical disease would be a risk. The seroprevalence of A. marginale, however, suggests that endemic stability with respect to this disease could exist in districts other than Angonia. There was no strong and consistent relationship between the intensity of control and the likelihood of seropositivity to either of the diseases.

Agglutination Tests↗

PubMed2005

The susceptibility of Trypanosoma congolense isolated in Zambézia Province, Mozambique, to isometamidium chloride, diminazene aceturate and homidium chloride.

Resistance to trypanocidal drugs has been detected in various African countries and is a serious impediment to the control of livestock trypanosomosis. To determine whether drug resistant trypanosome strains are present in the Zambézia Province of Mozambique a study was initiated. To assess the effect of the farming system and the drug-use regimen on the development of drug resistance, trypanosome isolates were collected from cattle from subsistence and commercial livestock production systems. The susceptibility of seven isolates against isometamidium chloride, diminazene aceturate and homidium chloride was tested in mice using a multiple-dose test. In four of the seven isolates high levels of drug resistance to diminazene aceturate and isometamidium chloride were detected. In most cases the observed levels of drug resistance correlated with the drug-use practices in the particular livestock production system.

Animals↗

PubMed2004

Development of image analysis techniques as a tool to detect and quantify morphological changes in anaerobic sludge: I. Application to a granulation process.

Image analysis techniques were developed and applied to quantify the process of anaerobic granulation in an expanded granular sludge blanket reactor (EGSB) fed with a synthetic substrate based on glucose [60-30% COD (chemical oxygen demand)] and volatile fatty acids (40-70% COD) over 376 days. In a first operation period that lasted 177 days, the aggregation of dispersed sludge was quantitatively monitored through the recognition and quantification of aggregates and filaments. A parameter defined as the ratio between the filaments' length and the aggregates projected area (LfA) has proven to be sensitive to detect changes in the aggregation status of the anaerobic sludge. The aggregation time-defined as the moment when a balance between filaments' length and aggregates' size was established-was recognized through the LfA. The percentage of projected area of aggregates within three size ranges (0.01-0.1 mm, 0.1-1 mm, and >1 mm, equivalent diameter) reflected the granular size spectrum during the aggregation process. When sudden increases on the upflow velocity and on the organic loading rate were applied to the previously formed granules, the developed image analysis techniques revealed to be good indicators of granular sludge stability, since they were sensitive to detected filaments release, fragmentation, and erosion that usually leads to washout. The specific methanogenic activities in the presence of acetate, propionate, butyrate, and H(2)/CO(2) increased along the operation, particularly relevant was the sudden increase in the specific hydrogenophilic activity, immediately after the moment recognized as aggregation time.

Algorithms↗

PubMed2004

Ixodid ticks on dogs in southern Mozambique.

The objective of this study was to determine the species and distribution of ticks infesting domestic dogs in southern Mozambique. To this end 89 collections were taken from dogs and the geographic coordinates of the localities at which they were made noted. Fifty-eight of these collections were from animals in the city of Maputo and 16 from animals at rural settlements close to Maputo. A further 15 collections were made from dogs in rural environments north of Maputo. Ten ixodid tick species, of which one was only identified to genus level, were recovered. Rhipicephalus sanguineus was the most numerous of the ten species, and its prevalence and intensity of infestation were significantly higher on city dogs than on rural dogs (P < 0.01), whereas the converse was true for Haemaphysalis leachi (P < 0.01). Including the city of Maputo, the exact localities at which nine tick species were collected, were recorded.

Animals↗

PubMed2001

Addition of hypoxanthine to culture media allows in vitro cultivation of Babesia bovis and B. bigemina at reduced serum concentrations.

The microaerophilous stationary phase system (MASP) was introduced in 1980 and successfully used as a standard technique for Babesia bovis and B. bigemina in vitro culture. The percentage of serum in the medium and the dependence on specific serum donors have been recognized as important constraints both for immunochemical studies and for the logistics of culture routine. In the present study the supplementation of RPMI 1640 with hypoxanthine at a concentration between 50 and 200 microM has enabled patterns of growth of B. bovis and B. bigemina to be achieved comparable to the standard technique with a simultaneous reduction of serum concentration from 40% to 5%. With hypoxanthine-supplemented medium it was possible to either replace the bovine serum from a specific donor with horse serum or use commercial adult bovine serum or foetal calf serum at 10%. When the serum replacement media Albumax II and GF21 were used, the growth of both B. bovis and B. bigemina markedly decreased after 3 x 72 h cycles. However, when these species were cultivated in culture flasks previously coated with cells from a murine peritoneal lavage, continuous parasite growth was achieved.

Animals↗

PubMed2000

The distribution of tsetse (Diptera: Glossinidae) and bovine trypanosomosis in the Matutuine District, Maputo Province, Mozambique.

A tsetse and bovine trypanosomosis survey was conducted during 1998 and 1999 in the Matutuine District of Maputo Province (Mozambique). A total of 59 Glossina brevipalpis and 17 Glossina austeni were captured throughout the district. Survey results suggest that Glossina brevipalpis is mainly concentrated in dense vegetation along the Maputo River and in the wetlands east of the river. G. austeni, on the other hand, was captured mainly in dense thickets in drier areas. Both tsetse species are suspected to be vectors of bovine trypanosomosis. Bovine trypanosomosis (75,5% Trypanosoma congolense) was diagnosed in 53 animals (13,9%) from seven sampling sites distributed throughout the district. The prevalence of cattle with anti-trypanosomal antibodies was high (29,9%). The incidence of trypanosomal infections in sentinel cattle was also high. The widespread distribution of bovine trypanosomosis and the high prevalence of infection are likely to have a significant impact on cattle production and, hence, the cattle restocking exercise in the district.

Animals↗

PubMed1997

[Coronary disease in the postmenopausal woman. The experience of an intensive care unit over 10 years].

OBJECTIVES: Analysis of the characteristics of acute myocardial infarction in female patients admitted to a coronary care unit during a 10 year period. DESIGN: Retrospective analysis of computerized data collected during a 10-year period in every patient with acute myocardial infarction admitted between 1986 and 1995. SETTING: A coronary care unit of a central hospital. PATIENTS AND METHODS: Data on 2439 patients were analyzed in what concerns gender, age and hospital mortality. In the restricted group of 655 patients admitted between 1993 and 1995 the prevalence of the following risk factors was assessed: arterial hypertension, dyslipidemia, smoking and diabetes mellitus. RESULTS: During a 10-year period, 1918 male (M) and 521 female (F) patients were admitted, originating a 3.5 to 1 M:F ratio. The M:F relation decreased from decade to decade from 11:1 in patients under 50 years old to 1.8:1 in patients over 70 years old. Hospital mortality was 25.9% in female patients and 12.0% in male patients (p < 0.001). Mortality was similar in males and females until 60 years of age; significant differences were found only in the seventh decade of life (25% in females vs. 12% in males, p < 0.001) and in patients over 70 years old (36% in females vs. 24% in males, p < 0.005). Hypertension was significantly move prevalent in females (66% in females vs 46% in males, p < 0.001) as well as diabetes mellitus (31% in females vs. 20% in males). Similarly, a previous history of dyslipidemia was more frequently found in females than in males, but the difference was not significant (24% vs. 19%, respectively). On the contrary, smoking was significantly less frequent in female patients (11% in female patients vs. 44% in male patients, p < 0.001). CONCLUSIONS: The probability of the occurrence of acute myocardial infarction is very low in premenopausal women. The M:F ratio decreases with aging. The risk of death progressively increases with age, and it is significantly higher in females in relation to males after the age of 60 years. Women, besides being older, have a higher prevalence of coronary artery disease risk factors, namely hypertension, diabetes mellitus and dyslipidemia.

Adult↗

PubMed1995

Wall motion abnormalities and late ventricular arrhythmia during the predischarge phase of acute myocardial infarction.

BACKGROUND: Left ventricular wall aneurysm is a complication of acute myocardial infarction which has been considered a precipitating factor of cardiac failure and ventricular arrhythmia. We have evaluated the relation between severe left ventricular wall motion abnormalities and ventricular arrhythmia. METHODS: During a two-year period 146 patients admitted to a coronary care unit with acute myocardial infarction were studied. Radionuclide angiography performed within the second and the fourth weeks was used to analyse phase and wall motility changes, and patients were divided into three groups: 1) Hypokinesia and/or akinesia localized to one segment: with no or slight changes in phase image--102 patients; 2) Aneurysm: left ventricular deformity with well-defined chromatic changes in phase image--19 patients; and 3) Dyskinesia and/or extensive akinesia of two or more segments: phase image with diffuse heterogeneous changes--25 patients. Ventricular arrhythmia was studied using Holter electrocardiography taken during the second week of acute myocardial infarction. Three rhythmic profiles were considered: no premature ventricular contractions--41 patients; with three or more than three premature ventricular contractions per hour--38 patients; repetitive premature ventricular contractions--20 patients. RESULTS: Premature ventricular contractions were absent in 31 (30%) of the patients with hypokinesia/localized akinesia vs 8 (42%) of the patients with aneurysm, and vs 2 (8%) of the patients with dyskinesia/extensive akinesia. Premature ventricular contractions were frequent (> or = 3/h) in 22 (22%) of the patients with hypokinesia/localized akinesia vs 4 (21%) of the patients with aneurysm (p = 0.35; NS), and vs 12 (48%) of the patients with dyskinesia/extensive akinesia (p=0.003). Repetitive premature ventricular contractions were present in 10 (10%) of the patients with hypokinesia/localized akinesia vs 2 (11%) of the patients with aneurysm, and vs 8 (32%) of the patients with dyskinesia/extensive akinesia (p=0.008). CONCLUSIONS: We conclude that the presence of aneurysm was not associated with a higher occurrence of ventricular arrhythmia, but patients with dyskinesia/extensive akinesia had a higher occurrence of ventricular arrhythmia, > or = 3 premature ventricular contractions per hour and repetitive premature ventricular contractions. Our results suggest that ventricular arrhythmia is related to functionally severe wall motion abnormalities, and not to anatomical discriminants. This finding leads us to suggest different electrophysiological mechanisms behind these two entities.

Adult↗

PubMed1993

Antibodies to Cowdria ruminantium in Mozambican goats and cattle detected by immunofluorescence using endothelial cell culture antigen.

Endothelial cell cultures, established from bovine umbilical cord arteries and subsequently infected with Cowdria ruminantium, were used as antigen in the indirect fluorescent antibody test. Bovine sera (374) and caprine sera (388) collected in 6 provinces of Mozambique were tested. Overall, 30.4% of goat sera had antibodies to Cowdria, and 43% of sera collected from cattle. North of the River Save, where the tick Amblyomma variegatum is highly prevalent, overall percentages of positive sera were low, 10% in goats and 20% in cattle. However, south of the river where the tick Amblyomma hebraeum is abundant percentages were much higher, 63.5% in goats and 59.4% in cattle. These results are discussed in relation to field observations that clinical disease is rare or absent in the north with enzootic instability in goats and Friesian calves in the south.

Animals↗

PubMed1990

[Rhythmic profiles of the late phase of acute myocardial infarction as a function of age].

OBJECTIVES: To evaluate the incidence of ventricular arrhythmias in the late phase of acute myocardial infarction (AMI) and to compare it with the following clinical parameters: age, sex, AMI localization, ventricular function (Killip classes), maximal creatinokinase (CK max) and the presence of sinus tachycardia. DESIGN: Prospective study, during a period of 31 months, of a non-selected group of patients with AMI. SETTING: Coronary Care Unit (UTIC-Arsénio Cordiero). PATIENTS: Non-selected group of 153 patients with acute myocardial infarction who survived the second week of disease. MATERIAL AND METHODS: 24-hour Holter ECG performed between the 4th and the 25th day of AMI. The patients were divided into two groups according to the hourly frequency of premature ventricular beats (PVB): less than 3 per hour (PVB less than 3/h) and 3 or more per hour (PVB greater than or equal to 3/h). RESULTS: PVB greater than or equal to 3/h occurred in 36 patients (24%). There was no differences in the occurrence of ventricular arrhythmias between sex, AMI localization, AMI size evaluated by CK max, and the presence of sinus tachycardia. Patients in Killip class III had more ventricular arrhythmias (67%) than patients in Killip class I (23%) (p less than 0.005), in Killip class II (18%) (p = 0.007), and in Killip IV (0%) (p = 0.017). In patients with serious left ventricular failure (classes III + IV) the ventricular arrhythmias were not significantly higher (40%) than in patients without serious left ventricular failure (classes I + II) (22%) (chi 2 = 2.5; p less than 0.25 NS). Patients with less than 41 years old had less PVB greater than or equal to 3/h (4%) than patients between ages 41-69 (24%) (p less than 0.05), and than patients over 70 years old (47%) (p = 0.00075). CONCLUSIONS: The majority of patients (76%) showed a low risk rithmic profile (PVB less than 3/h) in the late phase of AMI. Among all parameters the age of the patients was the one best related to the occurrence of ventricular arrhythmias. Sex, AMI localization, AMI size, and the presence of sinus tachycardia were not related to the presence of PVB. A slight tendency was found in patients with heart failure to have more PVB. On the other hand the elder group carried a statistically significant risk factor for a higher occurrence of ventricular premature beats.

Adult↗

PubMed1990

[A case of rupture of the left ventricle free wall with papillary muscle dysfunction following acute myocardial infarction, operated on successfully].

The authors present a case of left ventricular free wall rupture post acute myocardial infarction, associated with mitral papillary posterior muscle necrosis, operated by infartectomy and mitral valvular protesis replacement. They refer the various complications occurred during the hospital staying, and discuss its medical and surgical approach. The patient was discharged alive and six months after the infarction keeps a moderate activity.

Female↗

PubMed1989

[Holter ECG in evaluating myocardial ischemia. Validation using the exercise test].

OBJECTIVES: Validation of ST-T ischemic changes in the Holter system by those recorded in the 12-lead ECG during the exercise test. DESIGN: The changes induced by the exercise test in the ST segment of the two Holter leads--aVF e V5 like--were compared with the changes simultaneously registered in the 12-lead ECG. SETTING: Exercise Test Laboratory and Holter Laboratory of the UTIC-Arsénio Cordeiro. Hospital de Santa Maria de Lisboa. PATIENTS: 31 patients, 23 male and 8 female, with a mean age of 55 +/- 7 years, 84% with ischemic heart disease. METHODS: The patients underwent a treadmill exercise test. 28 with the Bruce protocol and 3 with the Naugton protocol, during which the electrocardiogram was registered simultaneously with a 2-channel Holter recorder and by a conventional 12-lead system. The changes induced in the ST segment in the two systems were compared. RESULTS: The results of the two tests were concordant in 94% of the patients. In 4 patients (13%) there was not a good correlation between the inferior and anterior leads of the two methods, which diverged mainly between the Holter lead aVF and the inferior leads of the conventional ECG. The morphology of the ST depression was similar in both methods, and the severity of ST depression as judged by its amplitude showed an excellent positive linear correlation (r = 0.8542, p less than 0.001). CONCLUSIONS: The sensitivity and the specificity of the Holter system is similar to the conventional 12-lead ECG in detecting ischemic changes during exercise whenever they have electrocardiographic evidence.

Adult↗