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O Silva

Publications and source records attributed to O Silva.

16 recordsLinked to original sources
PubMed2001

Magnetic resonance of a dextran-coated magnetic fluid intravenously administered in mice.

Magnetic resonance was used to investigate the kinetic disposition of magnetite nanoparticles (9.4 nm core diameter) from the blood circulation after intravenous injection of magnetite-based dextran-coated magnetic fluid in female Swiss mice. In the first 60 min the time-decay of the nanoparticle concentration in the blood circulation follows the one-exponential (one-compartment) model with a half-life of (6.9 +/- 0.7) min. The X-band spectra show a broad single line at g approximately 2, typical of nanomagnetic particles suspended in a nonmagnetic matrix. The resonance field shifts toward higher values as the particle concentration reduces, following two distinct regimes. At the higher concentration regime (above 10(14) cm(-3)) the particle-particle interaction responds for the nonlinear behavior, while at the lower concentration regime (below 10(14) cm(-3)) the particle-particle interaction is ruled out and the system recovers the linearity due to the demagnetizing field effect alone.

Animals↗
PubMed2000

Application of high performance liquid chromatography coupled with ultraviolet spectroscopy and electrospray mass spectrometry to the characterisation of ellagitannins from Terminalia macroptera roots.

PURPOSE: Terminalia macroptera roots are used in Guinea-Bissau and other West African countries to treat infectious diseases like gonorrhoea. Previous work showed an ethanol extract of T. macroptera roots (T) to have an in vitro antimicrobial profile against Neisseria gonorrhoae (including resistant strains) and enteropathogenic agents. The most active fractions of this extract were identified as the diethyl ether (T2) and water (T5) fractions. The aim of the present study was the identification of major compounds present in T and simultaneously in T2 or T5. METHODS: The T extract and T2 and T5 fractions were analysed by high performance liquid chromatography coupled with ultraviolet photodiode array (LC-UV) spectroscopy and electrospray ionization mass spectrometry (ES-MS). These analyses indicated the presence of ellagitannin derivatives. In order to confirm the identities of the detected compounds, they were isolated from T2 and T5 by preparative chromatographic techniques and identified by spectroscopic methods including tandem mass spectrometry. RESULTS: By using LC-UV-ES-MS, four major compounds (ellagic acid, gallic acid, punicalagin, terchebulin) could be identified in the T extract. Three other compounds (3,3'di-O-methylellagic acid, 3,4,3',4'-tetra-O-methylellagic acid, terflavin A) were also isolated and identified. CONCLUSIONS: LC-UV-ES-MS is a useful technique for the analysis of mixtures containing ellagitannins.

Chromatography, High Pressure Liquid↗
PubMed1997

Ursodeoxycholic acid in the treatment of cholestasis of pregnancy: a randomized, double-blind study controlled with placebo.

BACKGROUND/AIMS: Intense pruritus and the risk of stillbirths and premature deliveries justify the search for an effective pharmacologic treatment of intrahepatic cholestasis of pregnancy. This study was designed to test the efficacy of ursodeoxycholic acid in maternal pruritus, the biochemical abnormalities and the outcome of pregnancy, in patients with intrahepatic cholestasis of pregnancy of early onset. METHODS: Pregnant patients hospitalized in a secondary case-referral center with intense pruritus and abnormal serum levels of bile salts and aminotransferases, detected before week 33 of pregnancy, were randomly assigned to receive ursodeoxycholic acid, 1 g per day orally, or an identical placebo, until delivery, in a double-blind study. A 3-week trial period was chosen to compare drug and placebo effects. The follow-up was extended for 3 months after delivery. RESULTS: Twenty-four patients entered the trial; eight had deliveries before 2 weeks of treatment and one dropped out. The study was then completed in 15 patients: eight received ursodeoxycholic acid and seven placebo. No adverse effects were detected in the mothers or in their babies. After 3 weeks of treatment, patients receiving ursodeoxycholic acid (mean daily dose 16 mg/kg body weight) had a significant improvement in pruritus (p<0.02), in serum bilirubin (0.36+/-0.19 mg/dl (mean+/-SD) versus 0.95+/-0.48 in patients receiving placebo, p<0.01), in aspartate aminotransferase (52+/-42 IU/l vs 98+/-44, p<0.05) and in alanine aminotransferase (54+/-50 IU/l vs 229+/-154, p<0.01); serum total bile salts also tended to be lower in patients receiving ursodeoxycholic acid (26.3+/-33.7 micromol/l vs 55.0+/-44.8, p N.S.). Deliveries occurred at or near term in all mothers who received ursodeoxycholic acid (mean week of pregnancy: 38), while they occurred before week 36 of pregnancy in five patients who received placebo, including one stillbirth. All babies born alive had birth weights adequate for gestational age and they were thriving normally 3 months after delivery. CONCLUSIONS: Ursodeoxycholic acid is effective and safe in patients with intrahepatic cholestasis of pregnancy of early onset, attenuating pruritus and correcting some biochemical abnormalities in the mothers. Relevant aspects of fetal outcome were also improved in patients receiving ursodeoxycholic acid compared to placebo.

Adult↗
PubMed1997

Antimicrobial activity of Terminalia macroptera root.

Terminalia macroptera Guill et Perr. (Combretaceae) is a medicinal plant used in Guinea-Bissau and other West African countries to treat infectious diseases. The ethanol extract from T. macroptera decorticated root and their liquid-liquid partition fractions, were screened for antimicrobial activity, by the twofold serial microdilution assay against seven reference bacterial strains and against Candida albicans. The extract and fractions showed some activity against at least one of the test microorganisms. The best results were obtained against Shigella dysenteriae and Vibrio cholerae. The minimum inhibitory concentrations (MIC) of T. macroptera ethanol extract were also determined for about 100 clinical strains of Campylobacter sp., Escherichia coli, Salmonella sp., Shigella sp. and Vibrio cholerae. The ethanol extract activity against Campylobacter strains is similar to co-trimoxazole, higher than sulfamethoxazole but lower than tetracycline, erythromycin, ampicillin and streptomycin. Ellagitannins are the major compounds in the extract and active fractions. The obtained results suggest a potential importance of this medicinal plant in the treatment of enteric diseases, particularly in Campylobacter infections.

Anti-Bacterial Agents↗
PubMed1997

The significance of tumor contamination in the bone marrow from high-risk primary breast cancer patients treated with high-dose chemotherapy and hematopoietic support.

We studied the incidence and significance of tumor cell contamination of the bone marrow or peripheral blood progenitor cells of patients who had high risk primary breast cancer involving 10 or more axillary lymph nodes and who received high dose cyclophosphamide, cisplatin, and carmustine with hematopoietic support as consolidation following standard dose adjuvant chemotherapy. The autologous hematopoietic cell products were evaluated in 85 eligible patients. Eighty-three samples were available from the time of bone marrow harvest, and peripheral blood progenitor cells were evaluated from 57 of the 65 patients who additionally received these products. The screening technique utilized a panel of four anti-breast cancer monoclonal antibodies and an immunohistochemical technique. Thirty (36%) of the 83 evaluable patients had tumor cell contamination of the bone marrow. Only 2 (4%) of the 57 patients had tumor cell contamination of the peripheral blood progenitor cells. Tumor cell contamination of the bone marrow was associated with shorter disease-free survival and overall survival. In addition, the higher the number of tumor cells identified, the shorter disease-free and overall survival. There was no relationship between the tumor cell contamination of the bone marrow and the site of relapse. The combination of the log of the number of tumor cells +1 and number of positive lymph nodes predicted both disease-free and overall survival. Tumor cell contamination of the bone marrow from the harvest is associated with shorter disease-free and overall survival for patients who were treated with standard dose chemotherapy followed by consolidation with high dose alkylating agents and hematopoietic support. It is unclear what role the contaminating tumor cells have in relapse, and they may just be a high-risk marker. A comparison with other prognostic factors and characteristics of the tumor may determine the significance of the tumor contamination of the bone marrow.

Adult↗
PubMed1996

Antimicrobial activity of Guinea-Bissau traditional remedies.

The ethanolic extracts of twelve plants selected through ethnomedical survey in Guinea-Bissau were investigated for their in vitro antimicrobial properties over ten bacteria and Candida albicans, using agar diffusion and dilution methods. All the tested extracts showed some activity against at least one of the bacteria. Most of the extracts (79%) showed activity against Staphylococcus aureus and only one (Cryptolepis sanguinolenta) against Escherichia coli. Cryptolepis sanguinolenta and Terminalia macroptera root extracts showed some activity against Candida albicans as well as showing an interesting profile of activity against most of the enteropathogen microorganisms. Inhibition zones against Staphylococcus aureus were localised on extract chromatograms by bioautographic techniques.

Anti-Bacterial Agents↗
PubMed1996

A comparison of immunohistochemistry, two-color immunofluorescence, and flow cytometry with cell sorting for the detection of micrometastatic breast cancer in the bone marrow.

A significant percentage of women with primary breast cancer have micrometastatic disease in the bone marrow. Bone marrow involvement may be an adverse prognostic factor, and more aggressive therapy may be indicated for these patients. There are a number of different techniques and antibodies used to detect tumor cells in the bone marrow. We used the same panels of four antibreast cancer antibodies and compared three immunodetection techniques: two-color immunofluorescence, immunohistochemical staining, and fluorescence-activated cell sorting with cytologic examination of the sorted cells. The two-color immunofluorescence technique was superior and consistently detected one tumor cell contaminating one million normal bone marrow cells and had no reactivity with normal bone marrow.

Bone Marrow Neoplasms↗
PubMed1996

Correlation between the histopathology and the epiluminescence microscopy features of malignant blue nevus.

BACKGROUND: The validation of epiluminescence microscopy (ELM) for the diagnosis of pigmented skin lesions is conditional on the demonstration of consistent histologic correlates of the ELM patterns. The ELM characteristics of malignant blue nevus (MBN) have never been reported previously. OBJECTIVE: To evaluate the histologic counterparts of the ELM features of a case of MBN. METHODS: Comparison between the histologic characteristics observed in step-sections of the lesion and the structures observed in a digital ELM image. RESULTS: On ELM, the lesion showed a diffuse whitish-blue veil, round black blotches, a collection of dark colored punctate spots, and fragmented bluish reticular-like formations in the periphery. At histologic examination, the black blotches and the spots appeared to correlate with areas of intense focal necrosis in the papillary and reticular dermis, and the reticular-like structures were demonstrated to correspond to the presence of free melanin and melanophages in the papillary dermis. CONCLUSION: In this case of MBN, blotches and spots seen on ELM correlated with intense necrosis in the papillary and reticular dermis, and reticular-like formations were the counterparts of free melanin and melanophages in the papillary dermis.

Aged↗
PubMed1989

Preclausal patterns in language acquisition: a study of Spanish-speaking children in Chile.

Language utterances were recorded in three groups of 1- to 3-yr.-old day care children in Valdivia, Chile. An analysis of the preclausal patterns of language development according to the model outlined by Hubbell (1988) indicated that 4 of 12 major utterances--experiencer-state, action-object, agent-action, and negation-X--accounted for 68% of the total number of utterances recorded. The results suggest that preclausal patterns in language development of Spanish-speaking children are similar to and yet different in some respects from those of children who acquire English as their first language.

Child Language↗
PubMed1989

[Pre-existing diseases as risk factors and prognosis of genito-urinary infection in pregnancy].

With the intention of reducing the abortion, preterm delivery and perinatal mortality caused by the genito urinary infection (GUI) we attempt to identify the risk factors and with those make a diagnostic test, that permits detection and prediction of GUI during gestation period. Morbidity records that suggests alterations of immune response were studied in a group of 165 pregnant women that presented GUI and were compared with 86 pregnant women without GUI. As risk antecedents, we found: spontaneous abortions of second trimester 42.4% (study group) and 6.9% (control group) (p < 0.01), repeated vaginitis 31.5% and 2.3% (p < 0.01) urinary tract infection (UTI) 29.7% and 6.92% (p < 0.01), preterm deliveries 17.6% and 3.52% (p < 0.01), puerperal infection 9.12% and 0.0% (p < 0.05), familiar diabetes 21.2% and 8.12% (p < 0.05). Psychiatric pathology 12.72 and 3.5% (p < 0.05), typhoid fever 12.1% and 3.5% (p < 0.05) and surgical infections 16.4% and 8.12% (p < 0.1). A score was elaborated assigning 1/2 point to: puerperal infections, familiar diabetes, psychiatric pathology, typhoid fever and surgical infections; 1 point to: abortion, vaginitis, UTI and preterm delivery and 2 points to: repeated abortion, UTI and preterm delivery. Patients were divided in multiparous and primiparas. In multiparous with 1 or more points we found: sensitivity 75.3%, specificity 81%, positive predictive value 89.3%, negative predictive value 60.7% and accuracy 77.1%. In primiparas with 1/2 or more points we found: sensitivity 61.8%, specificity 70.5%, positive predictive value 78.3%, negative predictive value 51.7% and accuracy 65%.

Abortion, Spontaneous↗
PubMed1984

Effect of restricted suckling on pregnancy rates and calf performance in Brahman cows.

Seventy-six Brahman cows and first-calf heifers were assigned to one of two groups: 1) normal suckling (34 cows) or 2) twice-daily suckling (45 minutes of suckling each time; 42 cows). Twice-daily suckling was carried out from 30 days postcalving until weaning (seven months). All animals were maintained under artificial insemination for a four-month breeding period. Mean pregnancy rate was 63.06 +/- 0.06% and was influenced by suckling group (P<0.01) and number of parturitions (P<0.05). The pregnancy rates were 33% higher in twice-daily suckled cows. Forty-four percent of the first calf heifers in the twice-daily suckling group became pregnant compared to 9% in the normal suckling group (P<0.01). Twice-daily suckling improved pregnancy rate without depressing preweaning calf performance.

Journal Article↗
PubMed1984

Effect of restricted suckling on ovarian activity and uterine involution in Brahman cows.

Seventy-six Brahman cows and first-calf heifers ranging in age from three to five or more years were used to determine the effects of restricted suckling on postpartum ovarian activity and uterine involution. At 30 days postcalving, cows were randomly assigned to one of two groups: 1)normal suckling (34 cows) and 2)twice-daily suckling (42 cows). The cows were examined by rectal palpation weekly from parturition until the onset of the breeding season. The average interval from parturition to the presence of the first follicle larger than 10 mm (PPFI) was 36.0 +/- 1.0 days, and twice-daily suckling decreased PPFI length 8.1 days (P < 0.01); likewise, first- and second-calf heifers tended to have longer PPFI length (P < 0.05) than cows with three or more calvings. The average interval from parturition to first corpus luteum (PPCLI) was 59.0 +/- 2.0 days. PPCLI was affected by the age (P < 0.05) and weight of the cow at 30 days postpartum (P < 0.10). The average interval from parturition to first estrus (PPEI) was 68.0 +/- 5.0 days. PPEI was affected by suckling (P < 0.10) and month of parturition (P < 0.05). The average interval from parturition to uterine involution was 33.0 +/- 1.0 days. Uterine involution was influenced by month of calving (P < 0.01) and age of the cow (P < 0.05).

Journal Article↗
PubMedDate not supplied

Calcitonin in thyroidectomized patients.

Hypothyroid patients with total or near-total thyroidectomy were found to have detectable immunoreactive calcitonin in the serum and urine. These findings suggest that human calcitonin may be secreted by extrathyroidal tissues.

Adult↗