No abstract available

No abstract available

[en] Brazilians as other communities are also predisposed to osteoporosis; even though the condition of diet may vary, the exposure to sun light all year long may introduce a factor of variability in the frequency and presentation of bone metabolic disturbances. Studies have already shown decreased incidence of hip fracture in the Brazilian elders. Normal variation of bone mineral density has already been determined in selected groups of individuals in large cities, but without any reference to diet or exposure to sun. The aim of this study is to evaluate bone mineral density as well as define the peak of bone mass in a normal urban population from 5 to 50 year old (90 females and 90 males), correlating these data with nutritional intake, sun exposure and physical activity. As a complement to this project, bone biopsies will be taken from normal individuals who died in automobile accidents and elements like Ca, Zn, K, Na, Sr, Fe, Cl will be evaluated. (author)

No abstract available

No abstract available

[en] The use of antibodies as reagents in clinical chemistry for the quantitation of a wide range of analytes has now become widely established. Initially antibodies were employed in precipitation techniques, usually for the analysis of serum proteins, in solution or in the form of antibody containing gels, e.g. immunoprecipitation, immunodiffusion, and immunoelectrophoresis. Further developments have led to the highly sensitive techniques of radioimmunoassay and recently immunometric assay for the measurement of drugs, tumour markers and hormones. In general, those techniques without the addition of a label e.g. immunoprecipitation, immunodiffusion and immunoturbidimetry are the older techniques used for the measurement of serum proteins. These techniques are relatively insensitive, measuring at the g/L. level, and in the case of immunodiffusion are generally slow. Automation coupled with the development of chemistries to enhance precipitation has, however, reduced measurement times to minutes in modern laboratories. Nevertheless these methods have detection limits of the order of 1 g/L

[en] Three or four general strategies are adopted for the control of infectious diseases. Early diagnosis, vaccination and chemotherapy. In the situations where there is transfer through mosquitoes or ticks from alternate hosts, control of the vector and of the infection in the alternate host are additional measures to be taken. This Chapter looks at the problems of disease control from the perspective of genetics, since molecular genetics now provides powerful tools in the form of radiolabelled DNA probes and clones of selected segments, useful for diagnosis as well as for vaccine design

[en] Thyroid disorders may manifest as abnormalities of anatomy of function of the gland. Most of them can be diagnosed after a careful clinical history and physical examination. Nevertheless, laboratory evaluation is important for an accurate diagnosis before embarking on treatment. There is also a small but a significant fraction of thyroid diseases that can be diagnosed only on the basis of laboratory findings. Often a diagnosis of thyroid disease may need more than a single test. Hence, it is essential to select appropriate tests for thyroid patients by their reliability, precision and overall cost. Many thyroid function tests are nuclear techniques and this trend is not likely to change in near future. Radionuclides that are commonly used in the evaluation of thyroid disorders include iodine-131 (¹³¹I), iodine-123 (¹²³I), iodine-125 (¹²⁵I) and technetium-99m (⁹⁹TC^m-TcO4)

[en] The uptake of radioiodine by the thyroid gland is altered by the iodine content of diet or drugs. American diet has a high iodine content because each slice of the white bread contains nearly 150μg of iodine due to the bleaching process employed in the production of the bread. This carrier content of iodine reduces the uptake so much, that the normal American uptakes are usually three to four times lower than the uptakes in the developing countries. The other drawback of the thyroid uptake test is that it is affected by the iodine containing drugs. Anti-diarrhoea medications are quire common in the developing countries and many of them contain iodine moiety. Without a reliable drug history, a low thyroid uptake value may lead to a misleading conclusion

[en] A method for direct labeling of antibodies with 99mTc is described. Sodium Metabisulfite (SMB) was evaluated as a new reducing agent of disulfide bridges of the IgG molecule. Under selected experimental conditions, radiochemical purities of the label higher than 90.0% were achieved in most of the experiments. On the basis of the obtained yields an empiric equation which describes the system was computed as: Y=93.6+2.1X5 - 1.36X6+0.9X7. The absence of X4 indicated that the purification on Sephadex of the reduced IgG was not relevant to the labeling process. The most important variables were tin ion concentration (X5), the volume of Tin-Tartrate solution (X6) and the incubating time between reduced IgG and Tin-Tartrate solution (X7). A low aggregation and fragmentation of the IgG molecule was obtained when a SMB/IgG molar relation of 750/1 was used. The stability of the 99mTc-IgG was assessed by DTPA, HSA and L-Cysteine challenge studies. An acceptable level of dissociation was observed in presence of DTPA and L-Cysteine, when the Tartrate anion was used. However the transchelation level for HSA was about 80.0 per cent. These preliminary results showed that SMB could be a useful reducing agent for direct labeling of IgG. Further studies are needed to correctly evaluate it. (author)