Evaluation of a commercial process for collection and cooling of beef offals by a temperature function integration technique.

The hygienic adequacy of a commercial process for the collection and cooling of beef offals was assessed by a temperature function integration technique. The diverse operations for collection of offals were inspected. The rates of product movement through those operations, and the temperatures of products at the time of their being packed, were determined. From that information, four of the nine product types were selected for examination of their temperature histories during the assembly and cooling of the cartoned products. The products selected encompassed product at near-body and near-air-ambient temperatures at the time of packaging, product in the largest and smallest cartons used in the process, and product with relatively short and long residence times in an unchilled carton stack assembly area. Twenty-one temperature histories were collected for each of the products, and the possible proliferation of an indicator organism, Escherichia coli, calculated for each temperature history. The results were assessed against a temperature function integration criterion derived from studies of beef carcass and cartoned meat cooling processes. Products packaged at near-ambient temperature readily met with the criterion, but products packed at near-body temperatures did not comply. The latter non-compliance was extreme for product packaged in large cartons. However, the principal cause of non-compliance was identified as highly variable cooling conditions in the carton freezing facility. A brief survey of air speeds and temperatures within that facility indicated means by which product cooling could be better controlled.     

Measuring probe for fast transients monitoring in gas insulatedsubstation

This paper describes the construction of four probes adjusted for fast transient monitoring in 123 kV SF₆ insulated substations. The primary requirement was the ability to monitor without distortion very fast transients containing frequencies up to 200 MHz. The measuring system was tested and calibrated with the help of computer modeling techniques. The verified experimental apparatus was then used for testing and calibrating the measuring probes. During the test, various effects on the measuring system characteristics were analyzed with respect to materials used for the components of the system     

p53 in polyoma virus transformed REF52 cells

While cellular transformation by small DNA tumour viruses usually involves targeting the product of the p53 tumour suppressor gene by a virally encoded protein, none of the three polyoma virus (Py) specified T antigens have been observed to interact with p53. We show that primary mouse embryo fibroblasts and REF52 cells, which resemble primary cells in requiring co-operating oncogenes for transformation, cannot be transformed by the Py oncogene, middle T-antigen (PyMT), alone. These cells can be transformed by the complete Py early region, which encodes the Py large, middle and small T-antigens. We find that PyMT can transform rodent cells lacking a functional p53 protein (p53 null mouse embryo fibroblasts and DN-REF52 cells which contain a dominant negative p53). In Py transformed REF52 cells (Py-REF52) there is no significant accumulation of p53 protein, as opposed to SV40 transformed REF52 cells (SV-REF52) in which the amount of steady state p53 protein is elevated. However accumulation of p53 is observed following exposure of Py-REF52 cells to u.v. Treatment of Py-REF52 cells with X-rays results in a rapid increase in the levels of the p53-induced proteins p21/WAF1 and MDM2. In untransformed REF52 cells, X-irradiation causes p53 activation, which results in induction of both G1/S and G2/M blocks. In SV-REF52 and DN-REF52 cells, p53 abrogation results in the absence of both the G1/S and G2/M blocks. Only the absence of a G1/S block is observed in Py-REF52 cells exposed to X-irradiation. Together these results indicate that in contrast to most other DNA tumour viruses, Py does not appear to interfere with the DNA damage induced transactivation activities of the p53 protein but absence of a functional p53 protein can mediate transformation by the PyMT oncogene in the absence of other co-operating oncogenes. Possible modes of transformation by Py are discussed.     

Investigation of the production properties of filled fluoropolymers

Translated from Khimicheskoe i Neftyanoe Mashinostroenie, No. 4, pp. 32–33, April, 1991.     

Mikrobielle Werkstoffzerstörung – Schadensfälle und Gegenmaßnahmen: Umweltrechtliche Belange

Microbial deterioration of materials – case histories and countermeasures: Legal aspects of environmental protection Biofouling is a natural process. Usually, it does not cause too much harm if taken care of properly. If biofouling is fought by special means, problems may arise. The waste water does not meet the due standards. Sometimes the recipe of the treatment agent is not known. If the treatment causes more problems than it can solve help is needed quickly. Yet, it is advisable to keep one's mind clear. Wrong help can become very expensive. In addition, legal punishment will follow, if environmental legislation is hurt. Damages of the environment will be payed by an insurance company only, if the risk is covered by the insurance contract in advance. The best way to be sure is to have a good lawyer, a good expert in environmental techniques and environmental legislation, a good insurance, and to anticipate possible risks.     

Low density lipoprotein catabolism is enhanced by the cleaved form of alpha-1-antitrypsin

The frequent occurrence of hypocholesterolaemia following inflammatory processes is well known but unexplained. Elevated plasma levels of serine proteinase inhibitors (serpins) and their complexes with target enzymes have been demonstrated in inflammatory, malignant and infectious diseases which are also often accompanied by low plasma cholesterol levels. Under inflammatory conditions, uncomplexed, but cleaved inactive serpins arising from slow deacylation of the serpin-proteinase complex may be present in the circulation. To determine the influence of native and cleaved forms of serpins, such as alpha-1-antitrypsin (AAT), on lipoprotein metabolism, we investigated the effect of these forms on low density lipoprotein (LDL) catabolism in human HepG2 cell line. We have found that the cleaved form of AAT in concentrations from 125 to 2000 nmol l-1 stimulates LDL binding to the HepG2 cells, by up to 49% with a subsequent increase in LDL uptake and degradation of up to 79 and 65% respectively. Native AAT was also found to increase LDL binding and internalization by 20-25%, independently of the amount of AAT added, an effect most probably due to the cleaved form of AAT produced by local proteolysis of native AAT incubated in the cell culture. Moreover we have shown that the cleaved form of AAT interacts with LDL in vitro, and that such an interaction abolishes AAT ability to stimulate LDL binding and internalization. This study for the first time describes the ability of the cleaved form of AAT to stimulate LDL binding and internalization in HepG2 cell culture, and provides evidence that hypocholesterolaemia occurring during inflammatory processes may be mediated by cleaved forms of serpins.