Ultrastructure of the eye of Urastoma cyprinae (Turbellaria,Alloeocoela)

Summary Urastoma cyprinae (Graff) is a microturbellarian which has been recorded both as a free-living organism by Westblad (1955) and Marcus (1951) and as a commensal in various lamellibranch molluscs (see Burt & Drinnan 1968). The material used in this study came from oysters, Crassostroea virginica, collected off the coast of Prince Edward Island, in which hosts it occurs in large numbers especially during the summer months when the oysters are spawning (Fleming et al. 1981). When U. cyprinae is exposed to light as happens, for example, when an oyster is opened, it shows a marked negative phototactic response.Preliminary work on the fine structure of the photoreceptors in U. cyprinae shows that the two eyes each consists of: (1) a single cup cell full of relatively large, electron-dense pigment granules; (2) a tripartite conical lens system; and (3) what appear to be two photosensitive rhabdomes. The pigment cup cell has a single, well defined nucleus situated basally and close to the membrane of the pigment cell furthest away from the rhabdomeres. The lens system consists of a cone made up of three, separate but equal, parts. Each part has two, flat inner surfaces which join at an angle of 120°, an outer rounded surface, and a rounded upper surface. When these three parts fit together, the cone-shaped lens is formed with the apex of the lens within the cup of the pigment cell and the rounded, convex, broad end of the cone lying more or less at the same level as the top of the pigment cup and below the epidermis layer. The rhabdomeres lie between the electron dense lenses and the inside of the pigment cup. They show connections to the visual cells which are bipolar: one extension joining the rhabdomeres; the other constituting the axon which extends into the centrally situated brain or into the longitudinal, lateral nerves. The axons that enter the brain, form connections with other axons from the other eye. The axons that extend posteriorly in a lateral position, presumably play a role in facilitating the avoidance reaction.The chemical nature of the unusual lens has not yet been determined. This is presently under investigation and will be reported later at which time our work will be discussed in relation to other types of rhabdomeric eyes in the Turbellaria.     

On some commensal Turbellaria of the Canadian East Coast

The brachyurans Chionoecetes opilio and Hyas araneus collected from the east coast of Canada harbour two species of commensal turbellarians. Ectocotyla hirudo (Levinsen) and E. multitesticulata Fleming & Burt are found on the gills and branchial chambers of male and female crabs. The molluscs Crassostrea virginica and Mytilus edulis collected from several locations where they are cultured along the Northumberland strait carry two commensal eulecithophoran turbellarians, both on the gills, viz., Urasloma cyprinae (Graff) and Paravortex gemellipara (Linton), the latter being a new host record. Aspects of the biology and life-history of these turbellarians are discussed, especially in relationship to the biology of their hosts.Abbreviations in the figures A Atrium - An Antrum - C Capsule - CO Common Oviduct - E Embryo - Ep Egg-laying pore - GP Genital Pore - I Intestine - O Ovary - Od Oviduct - Og Ora-genital Pore - Ph Pharynx - Sp Sperm - SV Seminal Vesicle - T Testes - Va Vagina - Y Yolk     

Phosphorus-31 relaxation times of 2,3-diphosphoglycerate in intact human erythrocytes

The reciprocals of the spin-lattice relaxation times (T₁s) of the 2-P and 3-P nuclei of 2,3-diphosphoglycerate (DPG) increased linearly as percent DPG bound was raised in model hemoglobin solutions. The 2-P T₁ was slightly greater in intact erythrocytes than in model solutions under similar experimental conditions. The change in the 3-P T₁ with cellular deoxygenation was anomalous indicating that this nucleus should not be used to estimate DPG binding inside intact erythrocytes.     

Alpha glucosidases in white blood cells, with reference to the detection of acid alpha 1-4 glucosidase deficiency.

The iron-containing violet acid phosphatases from beef spleen and pig allantoic fluid have been purified to homogeneity. Molecular weight determinations by zonal gel filtration, SDS-gel electrophoresis, and ultracentrifugation support values close to 40,000 for both enzymes, necessitating reappraisal of literature values. Similarly, the equivalent weight for iron is close to 20,000 for both enzymes, indicating the presence of two iron atoms per molecule of enzyme. The enzymes also have very similar ultraviolet and visible spectra, with λ_max values close to 550 nm, and ?₅₅₀ values(in terms of iron) of 2.04 × 10³ and 2.00 × 10³ for the beef spleen and pig allantoic fluid enzymes respectively.     

On the effect of glucono-δ-lactone on the yeast Pichia polymorpha

Investigation has been made into the action of glucono--lactone on living cells of Pichia polymorpha in relation to the uptake of D-(U-¹⁴C) glucose, and the incorporation of (2-¹⁴C) uracil and L-(U-¹⁴C)-threonine into RNA and protein respectively. Other factors such as the action of glucono--lactone on cell morphology and on enzymic synthesis have also been studied. The action of this compound on -glucanase has been found to take place in the hydrolytic power and not in the synthesis.     

Dopamine receptor binding: differentiation of agonist and antagonist states with 3H-dopamine and 3H-haloperidol.

³H-Dopamine and ³H-haloperidol bind with high affinity and selectivity to synaptic dopamine receptors in membrane preparations of the calf caudate. Binding of both ligands shows marked regional variations with greatest density in caudate, putamen, globus pallidus, nucleus accumbens and olfactory tubercle, areas rich in dopamine nerve terminals. The rank-order of phenothiazines and related agents as well as catecholamines in displacing both dopamine and haloperidol binding closely parallels their pharmacological potencies and affinities for the dopamine-sensitive adenylate cyclase. Dopamine's affinity for specific ³H-dopamine binding sites is 100 times its apparent affinity for the dopamine sensitive adenylate cyclase. Agonists have about 50 times more affinity for dopamine than haloperidol sites, whereas antagonists display about 100 times greater affinity for haloperidol than dopamine sites.     

Synthesis of β-glucanase and other extracellular proteins by cells and protoplasts of the yeast Pichia polymorpha

The synthesis of β-glucanase either by cells or by protoplasts of the yeast Pichia polymorpha has been found to occur in the presence of 2-deoxy-d-glucose in the growth medium. On the other hand, the synthesis of typical extracellular proteins such as invertase and acid phosphatase is strongly affected by the presence of the drug. The degree of inhibition is, however, directly related to the 2-deoxy-d-glucose concentration.     

Preliminary note on anti-insulin antibody formation in diabetics treated with porcine insulin

In the present study, we have tested the sera of sixty five diabetic patients treated with insulin, researching the action of some physiologic and therapeutic factors (sex, age, insulin dose and time of treatment), to production of anti-insulin antibodies. Our results have shown that an important percentage of diabetic patients treated by porcine insulin produce antibodies: 72% of studied patients, concerning chiefly all the women and patients under-fourty years old. However our results have not pointed out any relation between the administered insulin dose versus the anti-insulin antibodies production, in spite of the early production of these antibodies in a great part of the patients.     

Parasitic effect of Opius concolor (Spzl) (Hymenoptera, Braconidae) on an intermediate host Ceratitis capitata Wied (Diptera, Trypetidae)

The parasitic incidence of Opius concolor (Hymenoptera, Braconidae) on a replacement host, Ceratitis capitata (Diptera, Trypetidae) was studied using polyacrylamide gel electrophoresis and immunoelectrophoresis methods. A noticeable modification of C. capitata proteins was observed when parasited by O. concolor. But the most important phenomenon is the finding of common antigens between the host and the parasite. These results are discussed with regard to trophic and parasitic behaviour of the parasite.