PubMed Health⌕ Search

Biomedical subjects

L M da Costa

Publications and source records attributed to L M da Costa.

6 recordsLinked to original sources
PubMed2001

Mobility of heavy metals as related to soil chemical and mineralogical characteristics of Brazilian soils.

In order to better understand the relationship between soil characteristics and mobility of some heavy metals, correlation studies were conducted in samples of unlimed and limed A, B and C horizons of three Brazilian soils, representative of the majority of the tropical soils. A number of chemical and mineralogical characteristics of one Oxisol and two Ultisols were related to the retardation factors (Rf) for zinc (Zn), cadmium (Cd), copper (Cu) and lead (Pb). The retardation factors, obtained in leaching column experiments, were used as an estimate of solute movement in the profile. Soil types and soil horizons were found to influence metal retardation factors which, in turn, correlated better with the chemical than the mineralogical soil characteristics. For the unlimed soil samples, the soil characteristics that significantly correlated with Zn-Rf and Cd-Rf were the sum of exchangeable bases (SB), and soil exchangeable (Ca-KCl) and non-exchangeable (Ca-HCl) calcium contents. These results showed the strong influence of the cation exchange phenomenon on the retention and mobility of these two metals. For Cu and Pb, not only SB, cation exchange capacity (CEC) and Ca-KCl and Ca-HCl but also the organic matter correlated well with the Rf, showing that complex or chelate formation may play an important role in the movement of these elements. The important soil chemical characteristics related to the retardation factors in the limed soil samples were SB for Cd, and Ca-HCl for Cu and Pb, suggesting that precipitation may also influence the mobility and retention of the latter two heavy metals in these soil samples. Soil pH influenced the heavy metals adsorption and movement as shown by the significant correlation with the retardation factors when the combined data for the unlimed and limed soil samples was considered.

Adsorption↗
PubMed2000

Utilization review: a practical approach for physicians.

Rhode Island has rules and regulations for UR, as well as an appeals process. When the appeals process is used, it is more often than not successful. (Table 1) If questions arise concerning the UR Act, the UR process, the appeals process, the rights of patients, physicians, and reviewers, or the authority of the HEALTH, please contact OMCR. For a copy of the Rules and Regulations for the Utilization Review of Health Care Services (R23-17.12-1-UR), please write: Rhode Island Department of Health Office of Managed Care Regulation 3 Capitol Hill Cannon Building, Room 410 Providence, RI 02908.

Certification↗
PubMedDate not supplied

Rickettsiae-infected ticks in an endemic area of spotted fever in the State of Minas Gerais, Brazil.

A study on tick-borne rickettsiosis was developed in the county of Santa Cruz do Escalvado, State of Minas Gerais, Brazil, where a clinical case of the disease, confirmed by necropsy, had been reported. Of the 1,254 ticks collected, 1,061 belonged to the Amblyomma genus, 57 to the Rhipicephalus sanguineus species, 81 to Boophilus microplus, and 46 to Anocentor nitens. The hemolymph test associated with Giménez staining showed that 18 of the 221 A. cajennense specimens, 1 of the 16 R. sanguineus, 1 of the 22 B. microplus, 3 of the A. nitens, and 1 of the A. ovale contained rickettsia-like microorganisms. Only 3 A. cajennense ticks were positive under direct immunofluorescence. A. cajennense was the only species found on humans.

Animals↗
PubMedDate not supplied

[Chlamydia trachomatis: significance of endocervical sampling in diagnosis by the Papanicolaou method].

One hundred and sixty-one cervicovaginal smears of women seen at the Instituto Adolfo Lutz, Laboratory I, in Taubaté (SP) were examined cytologically by the Papanicolaou method and by direct immunofluorescence (IF) for Chlamydia trachomatis (Ct). Thirty-three cases (20.5%) had positive results for Ct in the IF. With the Papanicolaou method, those cases presenting fine vacuolation in endocervical metaplastic cells according to recent criteria were suggestive of Ct infection. Compared to IF, the Papanicolaou method showed high sensitivity (91.6%) in the group of smears containing endocervical cells. The IF is a high sensitivity and specificity method, but its cost cannot be afforded by a great portion of our population. In view of the high incidence of Ct infection in the female genital tract, the authors concluded that the Papanicolaou method in smears containing endocervical cells may be considered the first option for the detection of this agent.

Adult↗