A capillary whole blood method for measuring the INR.

This study describes a method of measuring the INR on native whole blood capillary samples using Innovin recombinant thromboplastin. Modification of the reagent was necessary to compensate for the nonoptimal level of calcium in the sample/reagent mixture. Ninety-five percent of results obtained by the capillary blood method were no more than 0.42 INR higher or 0.38 INR lower than the venous blood method. The effect of changes in haematocrit was minimal. Significant differences in results were found between the Innovin and Thrombotest capillary blood methods. Provided the reagent was properly stored, there was no reagent drift and satisfactory results were obtained on samples supplied by UKNEQAS (coagulation) from previous trials. The method described is a convenient, simple and accurate method of measuring the INR using native capillary whole blood and Innovin recombinant thromboplastin.

Larval chemosensory projections and invasion of adult afferents in the antennal lobe of Drosophila.

We have studied the fate of olfactory afferents during metamorphic transformation of Drosophila melanogaster. Intracellular labeling of afferents from larval head chemosensilla suggests that the larval antennal lobe may be an olfactory target, whereas tritocerebral and suboesophageal centers are likely targets of gustatory sensilla. Application of monoclonal antibody 22C10 shows that the larval antennal nerve is the precursor of the adult antennal nerve and is used as a centripetal pathway for the adult afferents. Likely guidance cues are larval olfactory afferents that persist during early metamorphosis. P[GAL4] enhancer trap lines are introduced as efficient markers to follow the establishment of adult sensory projection. beta-Galactosidase and the bovine TAU protein were used as reporter proteins, and their expression patterns are compared. P[GAL4] lines MT14 and KL116 demonstrate that adult antennal afferents have arrived in the antennal lobe 24 h after pupariation and extend to the contralateral lobe 6 h later. Line MT14 expresses GAL4 mostly in basiconic sensilla and in certain trichoid sensilla, whereas KL116 is specific for trichoid and a small subset of basiconic sensilla. In the antennal lobe, largely complementary subsets of glomeruli are labeled by the two lines, in agreement with the observation that particular types of sensilla project to particular target glomeruli.

The role of the cut gene in the specification of central projections by sensory axons in Drosophila.

Mutations in the cut gene transform sense organs in Drosophila embryos from external sensory (es) receptors to chordotonal (ch) organs. We have investigated whether their central axonal projections are also transformed. Following Lucifer yellow injection of the sensory neuron, wild-type es and ch organs show characteristic, different projection patterns in the CNS. Transformed es neurons in cut embryos are variable in their projection patterns: some resemble wild-type es neurons, others ch neurons, while yet others are unlike either of these. We conclude that the cut gene influences axonal projections, although its action as a simple modality switch is open to question. Additional genes could be involved in the specification of the central axonal projection of the transformed neurons.