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991.
992.
Genetic engineering applied to the production of fish, molluscs, algae, algal products, and crustaceans in natural environments and hatchery systems is still at the rudimentary stage. Cloning systems for producing commercially important chemicals, pharmacologically active compounds, and metamorphosis-stimulating substances present in marine organisms are being sought. Attempts are being made to develop useful drugs from the sea, including antineoplastic, antibiotic, growth-promoting (or -inhibiting), analgesic, and antispasmodic agents. Immediate commercial applications can be expected from engineered systems involving polysaccharide and specialty chemical production, with marine microorganisms as the source of genetic material.  相似文献   
993.
994.
995.
1. When a solution of ferric ammonium sulphate was added to shell membranes of the domestic fowl, iron infiltrated the mantle (cortex) surrounding the cores of the individual fibres of the membranes.

2. Contraction of warm eggs in ice‐cold colloidal iron caused flooding of pore canals and contamination of the underlying shell membranes with this element.

3. Appreciable contamination of the inner shell membrane with iron persisted for 25 d in infertile eggs stored at 37.5 °C.  相似文献   

996.
1. The effect of feeding the detergent, sodium lauryl sulphate at concentrations up to 10 g/kg diet on egg‐shell quality was examined in laying hens at 24, 36 and 48 weeks of age.

2. Lauryl sulphate at 2.5 g/kg or more in the diet significantly increased shell breaking strength, shell thickness and shell weight at 24 and 36 weeks. In 48‐week‐old hens only shell breaking strength was increased significantly. Egg production and egg weight were not affected significantly by lauryl sulphate.

3. Lauryl sulphate might increase these measures of quality by increasing shell deposition and/or shell elasticity.  相似文献   

997.
998.
The pathology of carcinoma of the small intestine in six adult cattle is described. The lesions were similar to those of carcinoma of the small intestine of sheep although a slightly less fibrous stroma and a greater tendency to metastasise was observed. Initial findings suggest the disease resembles small-intestinal carcinoma of sheep and cola-rectal carcinomas of man in having a higher prevalence in New Zealand than most other countries. This highlights the need to investigate common environmental factors which may be responsible for the induction and promotion of these tumours in both grazing ruminants and man.  相似文献   
999.
Antiserum directed against equine intestinal Alkaline Phosphatase (ALP) was produced in rabbits and used to develop a sensitive and quantitative assay for the detection of intestinal ALP in equine serum. This assay was then used to measure the half-life of intravenously injected intestinal ALP and to determine if the intestinal ALP was present in normal horse sera, sera from horses presented for lesions not involving the gastrointestinal tract and sera from horses presented with lesions involving the gastrointestinal tract. The results suggest that intestinal ALP is not likely to appear in equine serum even when gastrointestinal disease is present and, therefore, appears to be of no diagnostic value.  相似文献   
1000.
Equine herpesvirus abortion in Australia 1977 to 1982   总被引:1,自引:0,他引:1  
Until 1977 no case of abortion caused by equine herpesvirus 1 (EHV1) had been recorded in Australia although the virus, called equine rhinopneumonitis virus, had been known to have been present at least since 1962. Outbreaks of EHV1 abortion occurred in New South Wales in 1977 and in 1981. Sporadic cases of EHV1 abortion had been confirmed in some parts of Australia each year since 1975. It was concluded that an abortigenic subtype of EHV1 had been introduced to Australia in 1977 and that the previously endemic respiratory subtype occasionally caused abortion. Virus isolation in a variety of cell cultures and histopathological examination of tissue were shown to be satisfactory methods of diagnosis of EHV1 abortion. Lung proved to be the specimen of choice. Slight serological differences between "abortigenic" and "respiratory" subtypes of EHV1 were found in cross neutralisation tests. A serological survey of 219 Sydney horses of various ages revealed that most yearlings had already acquired neutralising antibody to both subtypes.  相似文献   
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