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Biomedical subjects

D R Barnard

Publications and source records attributed to D R Barnard.

53 records · Page 3Linked to original sources
PubMed1985

WHO/FAO Working Team Report: entomology.

A summary of the more important concerns of the Working Team with particular reference to bluetongue (BT) virus (BTV), is as follows: With the exception of Australia, the US, and possibly parts of Africa, there are almost no concrete data that could be used to direct control efforts against the responsible vector(s) of BTV in a specific geographic area. In Australia, a broad plan of attack yielded data that showed that members of the subgenus Avaritia are the primary vector species. It has been clearly shown that Culicoides variipennis (Coq.) is the dominant vector species for most of the US. In the Middle East and certain areas of Africa, isolations from possible vector species indicated that C. imicola K., again probably a species complex and belonging to the subgenus Avaritia, is one of the likely vectors. Except for some subgenera, the taxonomy for much of the Culicoides remains in disarray. The subgenus Oecacta for example still remains a catchall for many species. Although a number of proposals have been made for delineating the species of the C. (Monoculicoides) variipennis species complex, none have been initiated because of the lack of funds. The Working Team strongly feels that the lack of definition of important species complexes is the result of short-term planning that does not consider the fact that efficiency can be increased and a great deal of monies saved by directing control toward the specific species or populations thereof that are responsible for a problem.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Inherited bleeding disorders in the newborn infant.

This article reviews the neonatal manifestations, diagnosis, and management of inherited bleeding disorders in newborn infants. Also considered are the problems of carrier detection and prenatal diagnosis. Normal values for coagulation factors in fetuses and infants are included in the discussion.

Blood Coagulation Disorders↗
PubMed1979

Neonatal thrombosis.

Abnormalities in blood flow, in blood vessel walls, in procoagulants, in circulating anticoagulants, and in the reticuloendothelial system may contribute to the thrombotic tendency of newborns. However, the importance of the role of each of these factors or other unmeasured factors is largely unknown. Most infants may be protected by their physiologic platelet dysfunction, increased fibrinolysis, and deficiencies in coagulation factors.

Adult↗
PubMed1979

Coagulation studies in extremely premature infants.

Evidence of developmental evolution of coagulation can be seen when the studies of 10 thriving extremely premature (EPT) infants are compared to normal full-term (FT) infants. The prothrombin time, partial thromboplastin time, and thrombin time all became shorter with increasing gestational age. Fibrinogen levels and platelet counts appear to be comparable to term infant and adult levels. Fibrin degradation products (FDP) of 10 micrograms/ml or less were found in the thriving EPT infants. When compared to healthy full-term infants, there is a definite gestational dependency of anti-thrombin III levels. Factors II and VII appear to be related to intrauterine maturation after the age of viability (24 wk), but factor VII-X complex does not. The contact factors XI, XII, high molecular weight kininogen (Fitzgerald factor), and prekallikrein (Fletcher factor) are all markedly decreased in thriving EPT infants. The mean factor V level is lower than that found in FT infants. This study confirms a gestational age dependency of factor VIII activity. The ratio of factor VIII antigen to factor VIII clotting activity is increased (2.8 vs 1.01 in FT and adults). Thriving small for gestational age (SGA) infants had coagulation studies which were not statistically different from those of thriving EPT infants. The coagulation changes which occurred in severely ill EPT were mainly in the factors which decrease during intravascular coagulation (factors I, V, and VIII). The present study suggests that because of the high antigen to activity ratio seen in thriving EPT infants, a dysfunctional or fetal factor VIII may have been produced. However, the further elevation of this ratio in the severely ill EPT infants is in keeping with a pathologic proteolysis or increased endothelial release of factor VIII antigen.

Blood Coagulation Factors↗