Regulation of lymphocyte proliferation after influenza virus infection of human mononuclear leukocytes

Previous studies demonstrated that in vitro infection with influenza A viruses altered several functions of human monocytes-macrophages but did not detectably alter functions of human lymphocytes. However, both types of cells were infected, as determined by production and surface expression of viral antigens. In the current studies, human mononuclear leukocytes were infected in vitro and assayed for both influenza virus-induced proliferation and mitogen (phytohemagglutinin [PHAl)-induced proliferation, as well as for ability to stimulate proliferative responses by normal autologous leukocytes. The leukocytes showed proliferation in response to the infectious virus, but concomitant depressed proliferative responses to PHA. Coculture experiments suggested suppression of PHA-induced responses by the virus-infected cells. However, upon coculture with fresh autologous leukocytes (without PHA stimulation), both virus-infected macrophages and virus-infected lymphocytes induced autologous lymphocyte proliferative responses. Altered proliferative responses to mitogen stimulation after exposure to the virus were not due to diminished interleukin-1 production or diminished expression of HLA-DR by monocytes-macrophages. The expression of influenza virus antigens and resulting induction of autologous proliferative responses, combined with depressed mitogen-induced proliferation, may be important in human antiviral defense.

Survival in chronic hepatitis B. An analysis of 379 patients

Survival data from 379 patients with chronic hepatitis B were analyzed to determine life expectancy for the patient from the time of first contact. One hundred twenty-one patients had chronic persistent hepatitis, 128 had chronic active hepatitis, and 130 had chronic active hepatitis with cirrhosis. The frequency of symptoms (p less than 0.001), stigmata of chronic liver disease (p less than 0.001), and liver function test abnormalities (p less than 0.001) increased as the histologic features worsened, whereas the percentage of patients with circulating hepatitis B DNA polymerase declined (p less than 0.001). Women were uncommon in our series and had less severe disease than men (p less than 0.02). Fifty-one patients had died by the time of this analysis. The estimated 5-year survival rates were 97% for patients with chronic persistent hepatitis, 86% for those with chronic active hepatitis, and 55% for those with chronic active hepatitis with cirrhosis. The usual cause of death was liver failure and its sequelae. A multivariate analysis found age of 40 years or more, total bilirubin level of 1.5 mg/dL or more, ascites, and spider nevi to be factors that identified patients at a higher risk of death. The prognosis for patients with chronic hepatitis B is similar to that for patients with chronic hepatitis of other causes.

Low dose prednisone therapy in rheumatoid arthritis: a double blind study

Prednisone, 5 mg taken each morning, was added to other drugs in 18 patients with rheumatoid arthritis. Sixteen patients were given a placebo in this double blind study. After 24 weeks, all patients were given the placebo. Slight functional improvement was noted in the prednisone group during the 24-week period, but deterioration after switching to placebo was sustained for at least 8 weeks. Progression of hand erosions occurred in 1 prednisone-treated patient, and in 4 controls. An asymptomatic vertebral spine compression fracture developed in 2 patients given prednisone; this was the only toxicity noted possibly due to this therapy. Minimal dose prednisone may be useful as "bridge" therapy between nonsteroidal antiinflammatory therapy and use of disease-modifying drugs.

Effect of Grinding Method on Textural Properties of Cooked Ground Beef 1, 2

Effects of eight grinding methods on textural properties of cooked beef patties were tested on beef from two sources. The methods tested were representative of those used by processors throughout the country and the sources were U.S. Choice chucks and U.S. Utility grade triangles. Patties from the .32 × .32 cm and silent cutter methods scored highest for tenderness and were lowest in amounts of subjectively determined connective tissue for both Choice and Utility grade beef. Sensory panel and Instron means indicated that the size of plate for initial grind was related (P < .10) to tenderness and the amount of connective tissue in the final product. Patties prepared by the 2.54 × .32 cm grinding method were generally inferior to patties prepared by the .32 × .32 cm grinding method.

Effects of Electrical Stimulation and Early Postmortem Muscle Excision on pH Decline, Sarcomere Length and Color in Beef Muscles

Electrical stimulation of prerigor beef carcasses produced a rapid initial drop in pH of longissimus muscles excised and vacuum-packaged at 1, 2 or 4 h postmortem. This initial drop was further increased by delayed excision and was severe enough that even -30-C storage did not retard the overall decline. Through the first 10 h of the 30-h sampling period at -30 C, pH was higher for nonstimulated than for stimulated muscle and was substantially affected by the time of muscle excision. Compared to -30-C storage, a 3-C storage temperature resulted in an even faster decline of pH in electrically stimulated muscle but still hindered the decline in nonstimulated muscle. Although the decline in pH was affected by electrical stimulation, excision time and storage method, initial (time of excision) and final (5 days postmortem) sarcomere length were not. Electrical stimulation of prerigor beef carcasses did not affect the appearance of hot-boned or cold-boned longissimus or semimembranosus muscles. Excision time, however, did affect the color and color uniformity of semimembranosus muscles, apparently because of alteration of the temperature and pH relationship. Excision times of 1 or 2 h appear preferable to 4 or 48 h because combinations of high temperature and low pH within deeper areas of the carcass could cause severe non-uniformity of color in muscles set deep within the carcass.

Device for Microbiological Sampling of Meat Surfaces

A coring device for sampling meat surfaces was developed. Aerobic plate counts of beef and pork carcasses were significantly higher when determined by the coring method than by the cotton or alginate swab technique.