Persistence of Hong Kong influenza virus variants in pigs.

The A/Hong Kong/1/68 (H3N2) influenza virus which has not been isolated from man for several years, was recently isolated from pigs in Hong Kong. Influenza viruses similar to A/Victoria/3/75, which are currently circulating in man, were also isolated from pigs. Both above-mentioned viruses could be transmitted readily from pig to pig in experimental studies. The isolation of influenza viruses similar to A/Hong Kong/68 from pigs in 1976 suggests that pigs may serve as a potential reservoir for future human pandemics as well as a possible source of genetic information for recombination between human and porcine strains of influenza virus.

Circulating ceruloplasmin is an important source of copper for normal and malignant animal cells.

The relative uptake of copper from ceruloplasmin and non-ceruloplasmin plasma pools, by normal and malignant cells, was investigated in vivo and in vitro, using 64Cu and 67Cu. 1. Most of the copper administered intravenously to normal and tumor-bearing rats was removed within 1 h, a substantial portion entering the liver. There were differences in the apparent avidity of individual tissue for ceruloplasmin vs. ionic copper, but when calculated on the basis of actual microgram absorbed, all showed a preference for ceruloplasmin. 2. Appreciable amount of copper from either source were also absorbed by the tumors, and cultured Ehrlich ascites tumor cells showed a rapid uptake and marked preference for ceruloplasmin over non-ceruloplasmin copper, as did primary rat muscle cell cultures. 3. Ceruloplasmin protein was also absorbed by normal and neoplastic rat tissues, but less rapidly than ceruloplasmin copper, as determined by administration of pure [3H]leucine- or [125I]ceruloplasmin. Copper deficiency did not accelerate this process. 4. It is concluded that, at least in rat, ceruloplasmin is the preferred plasma source of copper for normal and malignant cells, and that the copper on ceruloplasmin turns over more rapidly than the protein moiety, a finding consistent with its role as a copper transport protein.

A comparison of membrane vs. intracellular estrogen receptor-alpha in GH(3)/B6 pituitary tumor cells using a quantitative plate immunoassay.

The plasma membrane form of the estrogen receptor-alpha (mER-alpha) is involved in rapid estrogen-induced prolactin release from GH(3)/B6 rat pituitary tumor cells and can be detected immunocytochemically using several estrogen receptor-alpha (ER-alpha) antibodies. We recently described staining of fixed cells via a biotin-avidin-alkaline phosphatase sandwich assay. From this protocol, we have developed a rapid, quantifiable 96-well plate immunoassay for mER-alpha, using a different alkaline phosphatase substrate, para-nitrophenylphosphate, which generates a soluble yellow product, para-nitrophenol. We also permeabilized cells with detergent during fixation to measure intracellular ER-alpha (iER-alpha) with the same assay and then compared intracellular versus membrane ER-alpha levels in two GH(3)/B6 cell subclones originally selected for high and absent mER-alpha expression by immunocytochemistry. While the F10 subclone expresses plentiful amounts of the mER-alpha, the D9 subclone has undetectable levels of mER-alpha using this assay. In addition, there is a seven-fold difference in iER-alpha expression between the high (F10) and no (D9) mER-alpha expressing subclones. In the high mER-alpha expressing cell line, the mER-alpha totals approximately one third of total cellular ER-alpha. Neither membrane or intracellular forms of ER-beta were detected with this assay. The pNp assay allows convenient and quantitative comparison of multiple parameters of mER-alpha and iER-alpha regulation and should be applicable to other antigens that are expressed on the cell surface as well as intracellularly.

Bluetongue virus serotypes 20 and 17 infections in sheep: comparison of clinical and serological responses.

The clinical, virological and serological responses of sheep infected with an Australian bluetongue virus (BTV) isolate (serotype 20) were compared to responses in sheep inoculated with an American bluetongue isolate (serotype 17) with which it had shown cross-reactions in serum neutralization tests. In sheep inoculated with BTV 20, clinical signs were very mild and viremia was first detected by day 5; virus was isolated intermittently for a further 2 to 3 days. Neutralizing and precipitating antibodies were first detected in the serum of the sheep between 2 to 3 weeks following inoculation. In contrast, sheep inoculated with BTV 17 showed pyrexia and severe hyperemia of the nasolabial area and oral mucosa from day 7 to 17. Viremia was first detected on day 3 and extended to day 20, while the appearance and titers of serum antibodies was similar in both groups. After challenge with BTV 17 the sheep in both groups remained clinically normal, and virus was not detected in the blood; however, serum neutralizing antibody titers to both viruses increased 2 weeks after challenge and the mean titer of the two groups ranged from 1:250 to 1:640.

Electrophoretic comparison of the genomes of North American bluetongue viruses, one Australian bluetongue virus, and three other related orbiviruses.

The genomes of U.S. bluetongue viruses, an Australian bluetongue virus, and three other related orbiviruses were analyzed by polyacrylamide gel electrophoresis. The genomes were comprised of ten segments of double-stranded (ds) RNA. Estimates of the molecular weights of the dsRNA segments revealed that the U.S. bluetongue serotypes were remarkably similar. Although the dsRNA profiles of the viruses exhibited common segments, each virus had a distinct dsRNA profile. The usefulness of the genome analysis as a diagnostic tool for identification and for epidemiologic studies is discussed.

The role of HIV counseling and testing in the developing world.

The role of voluntary HIV counseling and testing is still under debate, especially in the developing world. HIV counseling-and-testing (HIV CT) services are a major component of HIV and AIDS control programs in the industrialized world and are increasingly being advocated in the developing world. In the United States, voluntary HIV CT has been a major component of HIV prevention efforts since the HIV antibody test became available in 1985. Yet even in the United States, questions about the management, cost, and effectiveness of voluntary HIV CT services continue to be raised. Because HIV CT has multiple goals, the evaluation of its effectiveness is a complicated task. Worldwide, a broad range of ethical, social, policy, technical, and economic issues encompass this HIV prevention activity. This article identifies the substantial barriers and serious concerns that are raised about HIV CT services and attempts to highlight the potential advantages of providing HIV CT as part of a developing country's comprehensive HIV prevention strategy.

Where injecting drug users receive HIV counseling and testing.

In 1990, nearly 1.5 million human immunodeficiency virus (HIV) antibody tests were performed at publicly funded sites. Eight percent of those tests were performed for self-identified illegal injecting drug users (IDU). The authors examined data from 28 project areas using a client record data base that permitted an analysis of self-reported risk behavior by type of service delivery site. Among self-identified IDUs, 68 percent of those tested and 82 percent of those found to be seropositive had obtained HIV counseling and testing services in settings other than drug treatment centers. The findings indicate that HIV-prevention programs for IDUs need to be available in various service delivery settings, not just in drug treatment programs. Strong links and cooperation between sites offering HIV counseling and testing and sites providing drug treatment programs are important to preventing HIV transmission to and from IDUs.

Clients without health insurance at publicly funded HIV counseling and testing sites: implications for early intervention.

The characteristics of clients reporting no health insurance were compared with those reporting any health insurance at publicly funded human immunodeficiency virus (HIV) counseling and testing sites in the United States during 1992. Thirty of 65 funded health departments collect data on self-reported health insurance status. Data were dichotomized into two groups, clients reporting any health insurance versus those reporting none, and multivariate logistic models were developed to explore independent associations. Of the 885,046 clients studied, 440,416 reported that they lacked health insurance. Clients without health insurance were more likely to be male, members of racial or ethnic minorities, adolescent, and HIV seropositive. Prisoners (odds ratio = 0.26), clients of Hispanic ethnicity (odds ratio = 0.52), and clients receiving testing during field visits (odds ratio = 0.53) in drug treatment centers (odds ratio = 0.55) and in tuberculosis clinics (odds ratio = 0.55) were less likely to have health insurance. Injecting drug users, whether heterosexual (odds ratio = 0.65) or homosexual (odds ratio = 0.67), were less likely to have health insurance compared with other behavioral risk groups. Large numbers of clients receiving publicly funded HIV counseling and testing lack health insurance. Lack of health insurance may interfere with subsequent receipt of needed primary care services among high-risk clients, especially HIV seropositive clients in need of early intervention services.

A study of clients returning for counseling after HIV testing: implications for improving rates of return.

Pretest and posttest counseling have become standard components of prevention-oriented human immunodeficiency virus (HIV) antibody testing programs. However, not all persons who receive pretest counseling and testing return for posttest counseling. Records of 557,967 clients from January through December 1990, representing more than 40 percent of all publicly funded HIV counseling and testing, were analyzed to determine variables independently associated with returning for HIV posttest counseling. On average, 63 percent of clients returned for posttest counseling. The rate varied by self-reported risk behavior, sex, race or ethnicity, age, site of counseling and testing, reason for visit, and HIV serostatus. In multivariate logistic models, persons who were young, African American, and pretest counseled in sexually transmitted disease (STD) clinics or family planning clinics were least likely to return for posttest counseling. Those clients who consider themselves to be at risk for HIV infection may be more likely to act on that perception and to follow through with posttest counseling than those who do not perceive risk. Counselors should make special efforts during pretest counseling to encourage adolescents, members of racial or ethnic minorities, and persons seen in STD and family planning clinics to return for posttest counseling by helping them understand and accept their own personal risk of HIV infection. Counselors need to establish, with the client's participation, a specific plan for receiving test results and posttest counseling.

Experimental placental transfer of foot-and-mouth disease virus in mice.

An attenuated type O foot-and-mouth disease (FMD) virus which was virulent for infant, but not for pregnant, mice proved to be superior to a virulent type C FMD virus in the development of a model system for the study of placental transfer of FMD in mice. When mice were inoculated at day 8 or 12 of gestation with type O FMD virus, the virus was detectable in the maternal pancreas for 3 days and in the placenta for 6 days. Viral levels in the fetus and the amniotic fluid were inconsistent and were apparently due to a spillover from the placental infection. The elimination of the virus from the placenta coincided with the expected production of maternal 7S antibody. Mice inoculated from days 0 to 12 of gestation did not have a significant increase in dead young by day 18 (the day of necropsy). Similarly inoculated mice, when permitted to go to term, produced and raised normal-size litters. Inoculation on day 15 of gestation resulted in an increased number of deaths due to morbidity of the dams. It was concluded that the placenta serves as an active site of infection for FMD virus in pregnant mice, but the fetus is relatively resistant to infection.

Experimental placental transfer of Akabane virus in the hamster.

Transplacental infection of hamster fetuses was produced by inoculation of pregnant hamsters with 10(6.3) plaque-forming units (PFU) of Akabane virus by either the intraperitoneal or the subcutaneous route. Virus with titers as high as 10(7.5) PFU/g of tissue was detected first in the placenta and later in the fetus. Virus could also be readily isolated from blood, lung, spleen, and liver of both pregnant and nonpregnant hamsters, but it reached higher titers and persisted longer in the placenta and fetus. Young dying at birth had Akabane virus titers as high as 10(7.3) PFU/g of brain tissue. Litter size was reduced by inoculation of the pregnant hamster at gestational day 11 or earlier, and survival of the newborn to 1 week of age was decreased by inoculation at gestational day 9 or later.

Vaccination for fowl plague.

Influenza A/turkey/Oregon/71 virus has antigenic characteristics of fowl plague virus but is avirulent for chickens. The virus was inoculated intratracheally in chickens at several dosage levels and resulted in the formation of antibody and immunity against fowl plague. The avirulent virus replicated in chickens and was recoverable by tracheal swab specimens up to 4 days after inoculation. Although the virus was transmitted to contact controls at the time when their cagemates were inoculated, it was not transmitted to contact controls placed with chickens inoculated 24 hours earlier. After 10 passages in chickens, the virus remained avirulent for chickens and turkeys.

Bluetongue virus serotype 20 infections in cattle of breeding age.

Ten cattle (6 heifers and 4 bulls) were inoculated with bluetongue virus (BTV) type 20. Clinical signs, antibody responses, and capabilities of these animals to replicate and maintain virus were assessed. The cattle showed no clinical signs of disease, although they did develop antibodies to BTV which showed long-term increasing titers. Virus was intermittently isolated from samples of blood, but not beyond day 21. Virus was not detected in the semen of the bulls, nor isolated from the tissues of the cattle at necropsy except from the genital tract of the 2 bulls which had been killed within 30 days after their inoculation. Gross and microscopic pathologic changes were not seen in any tissues that were attributable to BTV infection. There was no evidence of damage to the reproductive organs or of the development of a latent carrier state in either the heifers or the bulls.

Occurrence of idiopathic, familial hyperchylomicronaemia in a cat.

Primary hyperlipoproteinaemia (hyperchylomicronaemia with slight very low density lipoprotein elevation) is described in two related male cats. Fasting hyperlipaemia, lipaemia retinalis and subcutaneous xanthomas were detected on clinical examination. In one cat lipoprotein lipase activity measured after heparin activation was significantly reduced compared to the response in a normal cat. The lipid and protein concentration in each of the lipoprotein classes and the lipoprotein distribution of the two hyperlipaemic cats, two normolipaemic relations and 16 normolipaemic adult cats were determined. Plasma cholesterol and triglyceride levels were elevated in the hyperlipaemic cats with the major proportion of triglyceride and cholesterol being present in chylomicrons whereas in normolipaemic cats the majority of triglyceride was contained in very low density lipoprotein. High density lipoprotein was the predominant lipid carrier in both the normolipaemic and the hyperlipaemic cats but the protein content in chylomicrons was elevated in the two affected cats. The lipoprotein distribution in normal cats in this study agrees with previously reported values. The hyperlipaemic cats showed many of the features of familial lipoprotein lipase deficiency (type I hyperlipoproteinaemia, exogenous chylomicronaemia) which is an inherited disease in man.