Physical and Sensory Characteristics of Vacuum Packaged Beef Steaks and Roasts Treated with an Edible Acetylated Monoglyceride

Vacuum packaged strip loins and top rounds were fabricated into loin steaks and round roasts and treated, respectively, with 3 and 2% Dermatex® Food Grade (DFG), an acetylated monoglyceride. Samples were then vacuum packaged and stored at 2 ± 2°C for up to 49 (steaks) and 56 (roasts) d. Mean lean color (vacuum packaged and oxygenated), surface discoloration and overall appearance scores were not consistently different between treated and control steaks and roasts regardless of storage time. No consistent differences were observed in pH values of the lean and purge, percentage moisture or sensory evaluations of steaks and roasts treated with DFG before storage.

Induction and suppression of glutathione transferases by interferon in the mouse

The administration of interferon-alpha/beta to female nude (nu/nu) mice caused significant changes in the levels of the cytosolic hepatic glutathione transferases. Antibodies raised against rat subunits, Ya, Yc, Yb1, Yb2, and Yk, and the subunits of the human transferases, mu (YbYb), lambda (YfYf), and epsilon (B1B1) all reacted with enzymes in the mouse and were used to demonstrate suppression and induction of transferase levels. Western blot analysis followed by semiquantitation by laser scanning showed the Ya, Yb1, Yb2, Yc, Yk, mu, and B1 subunits to be suppressed by 11, 11, 44, 30, 12, 14, and 47%, respectively, by interferon treatment. In contrast to these findings, the Yf subunit was induced 5-7-fold. A concomitant 220% increase was observed in the specific activity of the hepatic cytosol for ethacrynic acid, a substrate for the Yf subunit. Changes in the levels of transferase enzymes in normal and tumor cells may have significant implications when cytotoxic drugs are used in combination with interferons in cancer therapy. The Yf subunit, an enzyme found in human tumors and in placenta (Polidoro, G., Di Mio, C., Del Boccio, G., Zulli, P., and Fererici, G. (1980) Biochem. Pharmacol. 29, 1677-1680) has also been shown to be elevated in hepatic preneoplastic lesions (Kitahara, A., Satoh, K., Nishimura, K., Ishikawa, T., Ruike, K., Sato, K., Tsuda, H., and Ito, N. (1984) Cancer Res. 44, 2698-2703). These data indicate that the Yf subunit represents a potentially important interferon-inducible gene product.

Interferon gamma regulates HLA-D expression on solid tumors in vivo

In vivo administration of recombinant human interferon-gamma, rIFN-gamma, to nude mice bearing human tumor xenografts resulted in a strong induction of HLA-DR expression on the tumor cells in 2 of 3 lines tested. The induction was dose-dependent and declined rapidly after cessation of therapy. IFN-gamma also switched on DQ and DP products when the xenograft cells were treated in vitro. The in vivo alteration of tumor surface properties by rIFN-gamma may have therapeutic implications.

Effect of Film Oxygen Transmission Rate on Lean Color and Microbiological Characteristics of Vacuum-Packaged Beef Knuckles

Seventy-two beef knuckles were packaged (n = 12) in each of six different bag types with oxygen transmission rates (OTR) of 1, 10, 12, 13, 30 and 400 cc/m²/24 h at 4°C and 100% relative humidity to study brown discoloration of knuckles during refrigerated storage. Knuckles in bag types of OTR of 1 and 12 cc did not discolor as compared to those in bags with higher OTR (30 and 400 cc) probably due to differences in oxygen tension in the package and in the types of bacteria present. Deterioration of lean color of knuckles in some bag types of low OTR appeared associated with large percentages of Leuconostoc mesenteroides in the microflora.

Methods of Chilling and Packaging of Beef, Pork and Lamb Variety Meats for Transoceanic Shipment: Physical and Sensory Characteristics

The effects of chilling/tempering treatments on the pH, weight loss and quality characteristics of beef, pork and lamb variety meats (livers, hearts, tongues and kidneys) that were packaged either in polyethylene (PE) bags or vacuum packaged (VP) in the USA and transported fresh-chilled to Antwerp, Belgium, were evaluated. Product arrived at the final destination 11 d after departure from the United States seaport (13 to 15 d after packaging). Changes in pH during overseas shipment were generally small and suggested a lack of product quality deterioration resulting from major microbial proliferation during this period. Variety meats that were not prechilled before packaging generally had the lowest weight loss among chilling/tempering treatments. In general, fresh-chilled variety meats that were vacuum packaged incurred less weight loss than those that were packaged in PE bags. Livers lost a greater percentage of their weight during shipment than did other variety meats. Vacuum-packaged variety meats had more desirable quality characteristics after shipment than those that were packaged in PE bags. Shipping fresh-chilled variety meats in PE does not appear feasible. Although some statistical differences were noted, the chilling/tempering treatments appeared to have little appreciable effect on quality characteristics of variety meats, with two exceptions: (a) cooler-chilled variety meats packaged in PE bags had superior quality characteristics as compared to those that were not prechilled and packaged in PE bags; and (b) livers that were not prechilled before vacuum packaging did not maintain their qualitative characteristics as well as did those in other chilling/tempering treatments.

Methods of Chilling and Packaging of Beef, Pork and Lamb Variety Meats for Transoceanic Shipment: Microbiological Characteristics

The effect of various initial chilling treatments on the numbers and types of microorganisms of beef, pork and lamb tongues (n = 60) and livers (n = 60) packaged either in polyethylene (PE) film or in vacuum packages in Texas and transported fresh-chilled via transoceanic shipment to Antwerp, Belgium, was evaluated. Initial chilling treatments included: cooler-tempered (4 to 6 h at 2°C), cooler-chilled (24 h at 2°C) freezer-tempered (0.5 to 1 h at -20°C), freezer-chilled (2 h at -20°C), ice-chilled (2 h in ice water slush) and no prechilling (NPC) before packaging and subsequent refrigerated storage at 2°C. After the initial chilling treatments, the microflora was varied with Micrococcus spp. with or without coryneform bacteria being the predominant bacterial types of most samples. After refrigerated storage for 13 to 15 d, lactic acid bacteria became dominant in most vacuum-packaged samples and in pork and lamb samples stored in PE film. Brochothrix thermosphacta and Pseudomonas spp. constituted a greater part of the microflora of beef tongues and livers stored in PE film than that of comparable vacuum-packaged samples. Increases in aerobic plate counts (APC) of refrigerated vacuum-packaged samples nearly always were greatest for samples (NPC) that were not pre-chilled before packaging and usually were smallest for samples that were either freezer-chilled, freezer-tempered or ice-chilled.

Positive interactions between interferon and chemotherapy due to direct tumor action rather than effects on host drug-metabolizing enzymes

The mechanism of increased antitumor activity when human lymphoblastoid interferon [HuIFN-alpha(Ly)] and the drugs cyclophosphamide and Adriamycin are used in combination on a human tumor xenograft in nude mice has been investigated. HuIFN-alpha(Ly) did not affect hepatic levels of the drug-metabolizing enzymes cytochrome P-450 or the glutathione S-transferases. In contrast, mouse interferon caused significant and differential changes in the isozymic forms of these enzymes. However, addition of mouse interferon to the HuIFN-alpha(Ly)/cyclophosphamide or Adriamycin combinations had no effect on the final result, and did not increase the toxicity of the combination therapy. These data provide evidence that the increased activity of the combination therapy is due to effects on the tumor rather than on the host. Further studies showed significant perturbations in the tumor cell cycle after in vivo combination therapy. Cyclophosphamide caused an accumulation in G2 and the addition of HuIFN-alpha(Ly), which alone caused little change in cycle distribution, delayed this G2 block and strongly increased the number of cells in S phase. A similar, although less pronounced, effect was seen with HuIFN-alpha(Ly)/Adriamycin therapy. The increase in S phase seen in combined therapy may account for the synergy seen.

Immune human lymphocytes produce an acid-labile alpha-interferon

We have described in this paper a novel human interferon (IFN) with antigenic and cross-species reactivity of alpha-IFN and physicochemical properties of gamma-IFN. This IFN is produced by normal peripheral blood mononuclear cells during an immune response but has also been associated with autoimmune disease (10). The system described here will be useful in elucidating the biological significance and cell of origin of this IFN.

A phase I study of human lymphoblastoid interferon administered by continuous intravenous infusion

A phase I study of human lymphoblastoid interferon (IFN-alpha) was undertaken in patients with acute leukaemia and other malignancies. The pharmacokinetics of intravenous IFN-alpha were also investigated. IFN-alpha was administered to two patients by intravenous (IV) bolus injection at a dose of 5 X 10(6) U/m2; and to a further 37 patients (40 cycles) by continuous intravenous infusion (IVI) for 5, 7, or 10 days at doses ranging from 5 to 200 X 10(6) U/m2/day. Pyrexia, general malaise, anorexia, and rigors were observed at all dose levels; three patients became hypotensive. Myelosuppression occurred in all patients, including seven without bone marrow infiltration. Transient rises in alkaline phosphatase and transaminases (SGOT) were observed in patients receiving daily doses greater than 30 X 10(6) U/m2. Dose-limiting central nervous system toxicity, hyperkalaemia, and hypocalcaemia were encountered at 200 X 10(6) U/m2. In six patients with acute leukaemia there was a fall in the number of circulating leukaemic blasts and in one patient with acute myelogenous leukaemia (AML) the degree of bone marrow infiltration decreased from 99% to less than 5% with cellularity returning to normal. Serum levels of IFN above 1,000 U/ml were achieved with daily doses above 30 X 10(6) U/m2 given by IVI. The maximum safely tolerated daily dose, 100 X 10(6) U/m2 administered for 7 days, is appreciably higher than that used in most previous studies, although even at this level considerable toxicity may be encountered.