No abstract

SummaryThrombospondin (TSP), a large glycoprotein present in platelets, and various normal and tumor tissues, has recently been shown to promote cell adhesion and platelet aggregation. Most importantly because TSP has been shown to promote metastasis of melanoma tumor cells to the lung in a murine model (1) and since thromboembolic events commonly occur in patients afflicted with metastatic tumors, we explored the role of TSP in human cancer by measuring TSP blood levels in patients with various malignant neoplasms. Blood TSP levels were measured by indirect enzyme-linked immunoadsorbent assay (ELISA) from 20 control subjects, 22 patients with gastrointestinal (GI) cancer, 18 patients with breast cancer, and 17 patients with lung cancer. Control subjects consisted both of healthy subjects and acutely ill patients with no malignancies. TSP levels of both healthy and acutely ill controls were found to range between 245-440 μg/ml with a mean of 365 μg/ml. In contrast, elevated levels of TSP greater than the mean value of 400 μg/ml for controls ranging between 590-3,650 μg/ml were found in 20/22 (91%) patients with GI malignancies, 13/18 (72%) patients with breast cancer, and 15/17 (88%) with lung cancer. Mean TSP levels of GI, breast, and lung cancer patients were 3, 2, and 3 fold greater than controls, respectively. Increased blood TSP levels in patients were not due to increased levels of platelets since both control and patient groups had platelet counts within the normal range. These results suggest that TSP may play a role in tumor cell metastasis in man and could serve as a blood marker for metastasis.

SUMMARYThe growth of coliform organisms on meat tissue from sheep carcasses processed in a commercial abattoir was investigated. The results indicated that for practical purposes the minimum temperature of growth of these organisms on meat may be taken as 8 'C. Equations were derived relating the generation time and the lag time of coliform organisms in raw blended mutton to the temperature at which the meat is held. Estimates of growth obtained with these equations were found to agree closely with the experimental results, especially at temperatures above 10°C, and allowed the generation times and the lag times for all temperatures up to 40 'C to be calculated. These times were also found to agree closely with the times determined using a strain of Escherichia coli inoculated into blended mutton tissue. A strain of Salmonella typhimurium inoculated in the same way into blended mutton tissue gave longer generation and lag times at temperatures below 15 'C. Therefore, it is believed that the calculated tables of lag and generation times included in this paper can be used to determine the length of time raw chilled meat may be held afterwards at temperatures above the minimum temperature of growth without an increase in the number of any salmonella organisms present, and these times include a safety margin at each temperature.The study indicates that the mandatory codes of practice presently applied in commercial abattoirs are too stringent. Maintaining the temperature of boning rooms at 10 'C or less does not appear to be necessary providing the meat is processed within the calculated time limits. A relaxation of the restrictions on boning room temperatures would decrease costs, increase worker comfort and safety and would not compromise the bacteriological safety of the meat produced.

No abstract

When 107–108Salmonella anatum or Salm. typhimurium were inoculated into the rumen of sheep consuming 1·3 kg of lucerne chaff daily, salmonellae were eliminated from the rumen in 2 days, and could not be detected in the faeces after c. 1 week. During starvation, both Escherichia coli and salmonellae grew in the rumen. Resumption of feeding after starvation for 3 days caused further multiplication of E. coli and salmonellae in the rumen. The organisms were subsequently eliminated with further feeding. Inoculation with as few as 400 salmonellae cells into a starved sheep led to large numbers of salmonellae appearing in the faeces and being excreted in varying numbers for at least 5 weeks after resumption of feeding.

A hot water cabinet based on an idealized distributor design for the decontamination of sides of beef is described and a laboratory evaluation of this novel cabinet is reported.Beef sides were inoculated with E. coli and exposed to mean water temperatures at the surface tissue ( Tf) of 83.5,74.2,66.0 and 44.5"C for 10 or 20 s. Mean loglo reductions of bacteria for 10-s exposures were 2.23, 1.40, 0.91 and 0.2. For 20 s, reductions were 2.98,2.14,1.17 and 0.1. There was a significant (P < 0.05) linear relationship between log reductions and Tf which varied with exposure time. At a Tf of 83.5"C with exposuretimes greater than 20 s, carcass bloom was judged to be permanently and adversely affected. At shorter times or with lower temperatures this did not occur. Evaporative heat losses were well correlated with the pressure driving force (r = 0.89) and gravity driving force ( r = 0.92) for air interchange between the cabinet and its surrounds.The running cost using the distributor cabinet was one-third of that of an existing spray cabinet when compared at the maximum reduction of log 1.3 (95%) achieved by the spray cabinet. An additional advantage of the distributor cabinet is its constructional simplicity.

Substantial transfer of R factors occurred in vivo, under certain conditions, in the rumen of adult sheep in the absence of any antibiotic treatment. A starvation period of 24-48 hr. was required to produce the conditions necessary, when even quite low inocula (ca. 10(3) cells) of donor and recipient E. coli could grow within the rumen and reach a population density sufficient for transfer to take place. The results indicate that under the same conditions R factors may be transferred between organisms in the lower intestinal tract also. Without the starvation period, the inoculation of even massive numbers (10(10) cells) of the same organisms resulted in almost no detectable transfer. Some of the experimental animals on which a starvation period was imposed became carriers of either the inoculated recipient E. coli, or of R factor bearing coliforms, and these formed 1-10% of the total coliform population of the faeces for at least 6 weeks.

Summary. When sheep were held in abattoir pens, the fleece became contaminated with salmonellae within 1 day even when there was less than 1 salmonella/g of soil. Salmonellae were first shed in the faeces after 2–3 days. Both the percentage of infected sheep and the number of salmonellae/g of faeces subsequently increased rapidly. Contamination of fleece and carcasses increased with time and with the degree to which the pens were contaminated. The fleece appeared to be a significant source of salmonella contamination of the carcass.