Although the presence of chitin in nematodes is well documented little is known about its synthesis in this phyletic group. The recently completed genome sequence of Caenorhabditis elegans predicts two sequences with homology to chitin synthases (chitin-UDP acetyl-glucosaminyl transferase; EC 2.4.1.16). We show that these genes are differentially expressed in a pattern that may reflect different functional roles. One gene is expressed predominantly in the adult hermaphrodite (the main egg-producing stage in the nematode) and later larval stages, which is consistent with a role in production of chitin for the eggshell. The other gene, however, is expressed in the cells that form the pharynx, and only in the period directly preceding a moult. These data suggest that the product of this gene is involved in synthesis of the feeding apparatus, which is replaced during each moult. We have also isolated a full-length genomic sequence of a chitin synthase orthologue from the plant parasitic nematode Meloidogyne artiellia. The single gene present in M. artiellia shows an expression pattern that is consistent with a role for the protein in production of the eggshell.
sphere which surrounds them ? Normal vitality is generally stronger than atmospheric impurity, and defeats the latter ; moreover, the body is largely adaptabe, and a town-bred person falling ill in a town may do better than a country-bred person under like conditions. Yet this adapted state is probablyvless vigorous than the normal state. But in many cases the swing of life is feebler, whether of operation, disease or childbirth, and atmospheric impurity may turn the scale against this numerous class. He had recently attended a lady in puerperal fever, who had come to reside in an old 'house, the drainage of which was simply unknown and had not been investigated within human memory, and no other cause of infection could be discovered. A servant maid was at the same time lying ill in a room alone in the second week of enteric fever. Omitting specific impurities-the causes of fevers, diphtheria, and the like-the speaker spoke more at length on phthisis, laryngitis, bronchiectasis, empyema, scrofulous adenitis, pyelitis, spinal caries, and cystitis.He,referred to the developmenit of phthisis in towns, of the poisoning of the otherwise perhaps transient pulmonary lesion by foul air, as a transient sore-throat becomes foul and incurable in a badly drained house. He then pointed out that such cases, where softening begins, die of local corrosion and of septicaemia caused by the fermentation of the masses in the lung. He had found antiseptic inhalations and respirators disappointing, probably because they are intermittent in action. And he admitted that, even in thought, it seems impossible surgically to reach or scour out the cavities, save in a few very rare cases. The best treatment he had discovered was that by the air of Alpine heights, proved by Professor Tyndall to be aseptic. Phthisical H. J., AGED 55, a healthy powerfully built man, was admitted int -this Hospital on January 17th, 1878. He had been knocked down by a traction engine. The nature of the accident was, obscttre; -but it was stated in evidence that he had faLlen in front of the engine, and that the wheel had pressed him to the ground but had not passed over him; he was unTable to move, so he was brought here. at once, where he arrived one hour after the accident.On admission, he was found to have a fracture of the right humerus. There were bruises on the left thigh and leg and over the crest-of the right ilium. On examining the pelvis, no signs of fracture or dislocation were elicited. There was no marked collapse, but he seemed a good deal shaken. The humerus was put up, and the patient removed to the ward. He was seen two hours afterwards, and he expressed himself as being quite comfortable, and in no pain. The shock had passed off, and he was able to take some beef-tea and milk. The urine, which was passed voluntarily, was quite free from blood. At 9 P.M., four hours after admission, he was again seen, and then for 'the first time he complained of pain, which he referred to the lower part of the abdomen. A poultice was ordered, and. a draught o...
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