Light and electron microscopic studies on the enzyme cytochemistry of leucocytes of eels, Anguilla species

The leucocytes of three anguillid eels were studied using enzyme cytochemistry. Leucocytes were stained for peroxidase, alkaline phosphatase, acid phosphatase, aryl sulphatase, β-glucuronidase, N-acetyl-β-glucosaminidase, β-galactosidase, lysozyme, a variety of non-specific esterases, chloroacetate esterase and two proteases. All cells were negative for aryl sulphatase, β-glucuronidase, N-acetyl-β-glucosaminidase, and β-galactosidase. Very few neutrophils, thought to be mature, and all eosinophils contained peroxidase-positive granules, and some monocytes showed very weak peroxidase staining. All leucocytes lacked alkaline phosphatase, but all cells except lymphocytes and thrombocytes of A. dieffenbachii contained acid phosphatase. Neutrophil acid phosphatase released into phagosomes was associated with Escherischia coli bacteriolysis. Neutrophils also secrete lysozyme and, with monocytes, produce and secrete a variety of esterases. The possible interaction of lysozyme, acid phosphatase and esterases in bacteriolysis is discussed.     

Diagnosis of ophthalmia neonatorum.

Ninety consecutively seen babies with eye discharge in the first three weeks of life were examined. Four babies had "sticky eyes" with no evidence of ophthalmia and had uniformly negative cultures and test results for antichlamydial antibody; these babies were excluded. Of the 86 babies with ophthalmia neonatorum, Neisseria gonorrhoeae was isolated from eight, Chlamydia trachomatis from 44, other bacteria alone from 20, and 14 had negative cultures. Three babies with negative cultures had longstanding conjunctivitis and had been treated with chloramphenicol eye ointment; all had antichlamydial IgM antibodies, indicating that the conjunctivitis was chlamydial. Hence the total number of babies whose conjunctivitis was chlamydial was 47. The result of the Gram stained conjunctival smear correlated well with that of culture and final assessment by the microimmunofluorescence test, enabling an immediate presumptive diagnosis to be made of gonococcal, chlamydial, or bacterial conjunctivitis. Prompt and effective treatment of babies was started. Explanation to the mother and contact tracing were carried out when the confirmatory cultures and antibody tests were completed. The Gram stained conjunctival smear is a highly sensitive, specific, and predictive test for the aetiological agent of ophthalmia neonatorum. By virtue of its simplicity and rapidity the test may be useful in developing countries.     

Evidence that muscarinic receptors in islet cells are not coupled functionally to adenylate cyclase through the inhibitory guanine nucleotide binding protein (Ni)

The effect of muscarinic agonist on adenylate cyclase was investigated in neonatal islet cells and in a clonal pituitary cell line (GH4C1) following labelling of the intracellular ATP pool with [2,8 3H]adenine. In islet cells carbamylcholine was without effect on basal or glucagon-stimulated adenylate cyclase activity, measured as 3H cyclic AMP production, but inhibited 3H cyclic AMP production in the clonal pituitary cells. The involvement of the inhibitory guanine nucleotide binding protein of adenylate cyclase (Ni) was investigated by the use of the Bordetella pertussis exotoxin, islet activating protein (IAP). Pre-treatment of islet cells with IAP was without effect on adenylate cyclase following carbamylcholine but in the clonal pituitary line abolished the inhibition of 3H cyclic AMP production. It is concluded that in the islet cell, in contrast to the clonal pituitary cell, muscarinic receptors are not effectively coupled through Ni to inhibit adenylate cyclase.