Studies on ulcerative dermal necrosis of salmonids

Fourteen fresh run salmon Satmo salar L. with early extant lesions of ulcerative dermal necrosis (UDN) were kept in separate tanks and treated with zinc free malachite green. Ten of the fish were held at 10° C and 4 at 2° C. The treatment precluded infection with Saprolegnia fungus and allowed natural resolution of the lesions. There was a marked difference in rate of healing between warm and cold water conditions.
Histological examination of healing lesions at different stages showed that there was a primary invasion of cuboidal epithelium over the collagen scar followed by a phase of disorganized proliferation which eventually organized itself into normal epithelium. Melanocytes were very obvious in the dermis of healing lesions.     

A discussion of microbial genetics in fermentation process development with particular reference to fungi producing high yields of antibiotics

When trying to improve antibiotic processes that are already high yielding, real industrial problems have to be faced. These include the use of organisms with non-ideal growth and recombination cycles, and problems of scale up from the laboratory to the main production plant. Many of the principles derived from academic studies have to be radically modified before they can be applied in the industrial context. These issues are a challenge to those who genuinely wish to contribute to the solution of industrial problems.     

A comparison of three salmonella antigen-capture ELISAs and culture for veterinary diagnostic specimens

Three sandwich-ELISAs, two of which are commercially available (Tecra and Locate), and one developed at the Veterinary Sciences Division, Stormont and a 3-step culture protocol, were compared for the detection of salmonella in 1000 animal specimens. Eight hundred and fifty of these were new submissions and the remainder were frozen portions from specimens previously shown to contain salmonellas by culture. The incidence of ELISA false-negative and false-positive results was highest for the Stormont and Locate kits respectively although the differences in sensitivity and specificity between the three ELISAs was not statistically significant. On 16 occasions all ELISA methods indicated the presence of salmonellas when none were isolated by initial culture, eight of these specimens contained salmonellas when reinvestigated by culture.     

Dimerization of 2,6-dimethoxyphenol by Aspergillus flavus: evidence for the reaction occurring close to mycelia

Aspergillus flavus grown on 2,6-dimethoxyphenol as sole carbon source produced tetramethoxy-p-dibenzoquinone by a free radical mechanism. The product was identified by H-nmr and ms. Scanning electron microscopy and light microscopy were used to follow the growth of mycelia and the attachment of crystals to the mycelial surfaces. Formation of dimer was inhibited by the presence of glucose in the medium.     

Phosphorylation of caldesmon77 by protein kinase C in vitro and in intact human platelets

Caldesmon is a widely distributed calmodulin- and actin-binding protein which occurs in different forms depending on the tissue or cell type under examination. On the basis of molecular weight, caldesmon species can be divided into two classes: caldesmon77 (Mr 70,000-80,000) and caldesmon150 (Mr 140,000-150,000). We have examined the phosphorylation of caldesmon77 by protein kinase C (the Ca2+/phospholipid-dependent enzyme) in vitro and in intact platelets. Caldesmon77, purified from bovine liver, could be phosphorylated by purified rat brain protein kinase C to a level of approximately 1.0 mol of phosphate per mol of caldesmon77 monomer. Two-dimensional tryptic peptide mapping and phosphoamino acid analysis reveals that caldesmon77 is phosphorylated at two major sites exclusively on serine residues. Following treatment of platelets with tumor-promoting phorbol ester, caldesmon77 phosphorylation was elevated 4-fold. Tryptic peptide mapping of phosphorylated platelet caldesmon77 demonstrates that phosphorylation is most significantly enhanced on two peptides which had migration patterns identical with those of the two major phosphopeptides of bovine liver caldesmon77 phosphorylated in vitro. The results of this study indicate that protein kinase C can phosphorylate caldesmon77 in vitro and in intact platelets, suggesting a role for protein kinase C in the regulation of caldesmon77 function or localization.     

A systematic study of the amino acid compositions and D/L ratios in fossil bones from two french neanderthalian sites

The reaction of racemization in which the L amino acids are reversibly converted into the corresponding D amino acids, proceeds in geological environment at such a slow rate that it may be used as a geochronometer. However, in fossils several parameters may affect the rate of racemization, i.e. moisture, surface, pH buffer and metal cations. This work consists of a systematic study of total amino acid content in fossil bones from two neanderthalian sites. The amino acid distributions of all specimens were determined and compared to that of fresh bone. The D/L amino acid were quantified and expressed in terms of age as a function of the temperature. The results led us to consider the «La Roquette» site older than «Les Canalettes» site.