Detection and characterization of hepatitis C virus RNA in immune globulins

BACKGROUND

Hepatitis C virus (HCV) RNA was measured in immune globulins and its chemical and physical properties were characterized.

STUDY DESIGN AND METHODS

The study examined 69 immune globulin lots from 7 manufacturers, including 44 intravenous and 25 intramuscular immune globulin preparations. In addition, 8 experimental intravenous immune globulin preparations were investigated. Detection and quantitation of HCV RNA were achieved by reverse transcription and nested polymerase chain reaction at limiting dilution. A multi-antigen anti-HCV enzyme immunoassay was also used to test these immune globulins.

RESULTS

The highest level of HCV RNA was found in an experimental immune globulin lot derived from a plasma pool made up of 186 anti-c100-3-reactive units. HCV RNA was detected only in 1 of 7 manufacturers' experimental intravenous immune globulin preparations derived from a pool made up of 2887 anti-c100-3-negative units. It was also detected in commercial intravenous immune globulin lots prepared by the same manufacturer from source plasma, but not from recovered plasma. More than half of the commercial intramuscular immune globulin lots, including specific immune globulin products, were HCV RNA positive. All immune globulin products examined were reactive for anti-HCV. Certain similarities were found for HCV RNA present in an immune globulin product and plasma. Ethanol at 20 or 25 percent had no effect upon the buoyant density of HCV RNA.

CONCLUSION

Many immune globulin preparations contained HCV RNA, with levels depending upon both the type of starting plasma and the manufacturing process. Exposure to ethanol did not appear to affect the physical characteristics of HCV RNA.

Immunogenicity of inactivated hepatitis A vaccine in children

BACKGROUND

Inactivated hepatitis A vaccine is now becoming available in many countries.

METHODS

To evaluate the immunogenicity and safety of inactivated hepatitis A vaccine in healthy children, 99 susceptible schoolchildren from 4 to 15 years of age received 360 enzyme-linked immunosorbent assay units of the inactivated hepatitis A vaccine at months 0, 1, and 6.

RESULTS

Antibody to hepatitis A virus seroconversion (> or = 20 mIU/mL) was 97% (96/99) in vaccinees after the first dose and 100% after the second (99/99) and booster (96/96) doses. The geometric mean titers of antibody to hepatitis A virus were 167, 465, and 4133 mIU/mL after each dose of vaccine, respectively. There were no significant side effects during the vaccination. Levels of antibody to hepatitis A virus were also tested in 9 susceptible children at day 7 and months 1 and 4 after the intramuscular injection of 2 mL of immune serum globulin. All children had measurable titers of antibody to hepatitis A virus 1 week after receiving immune serum globulin by sensitive enzyme immunoassay, but measurable titers had disappeared 1-4 months later.

CONCLUSIONS

The inactivated hepatitis A vaccine is safe and immunogenic in healthy children.

Flow cytometric detection of human red cells labeled with a fluorescent membrane label: potential application to in vivo survival studies

In vivo survival studies of human red cells (RBCs) are commonly carried out by using chromium-51 (51Cr), a gamma-emitting radionuclide, as the cell label. The effects of labeling human RBCs with PKH-2, a nonradioactive lipophilic fluorescent dye that binds to the cell membrane, and the feasibility of detecting the labeled cells by flow cytometric analysis were investigated. Optimal labeling, defined as maximum mean fluorescence intensity with minimal cell-to-cell variability in fluorescence intensity and minimal cell loss, was achieved with the use of 15.0 x 10(-6) M (15.0 x 10(-6) mol/L) PKH-2 and a cell concentration of 4.0 x 10(9) RBCs per mL. Both freshly drawn and stored RBCs could be labeled, but RBCs stored for more than 20 days did not take up the label as uniformly as fresher cells. Although labeling with PKH-2 did not interfere with the detection of ABO, Rh(D), or common minor RBC antigens by routine serologic methods, it resulted in a morphologic appearance resembling echinocytosis and an increased resistance to osmotic lysis by hypotonic saline. RBCs labeled by this method could be quantitated accurately in blood samples in which their proportion was 0.01 percent, or 1 labeled cell in 10,000 cells. This method holds promise as a simple, reliable, and sensitive method for the detection of labeled human RBCs, but the in vivo significance of the label's effects on cell morphology and osmotic fragility is not known. Further studies directly comparing PKH-2-labeled and 51Cr-labeled RBCs will be necessary to establish the accuracy of the former method in determining the in vivo survival of human RBCs.

Expression and characterization of the preS1 peptide of hepatitis B surface antigen in Escherichia coli

The infectious particles of hepatitis B virus (HBV) contain 3 related surface antigens, i.e., small, medium, and large, all of which are encoded by one large open reading frame with multiple initiation codons. The large surface antigen (L-Ag) contains preS1, preS2, and S regions while both the middle and small surface antigens lack preS1. Several lines of evidence suggested that the preS1 region is involved in the binding of HBV to human hepatocytes as shown by its binding to HepG2 cells and isolated human hepatocyte membranes. To obtain large quantity of preS1 peptide, an expression vector was constructed containing a lac promoter, the 5' half of the beta-galactosidase gene, the Factor Xa tetrapeptide recognition sequence, and the coding region of preS1 plus preS2. This recombinant plasmid constitutively produced high concentration of a fusion protein in inclusion bodies in Escherichia coli. When the fusion protein was treated with Factor Xa, a peptide consisting of the N-terminal 91 amino acids of the preS1 region was released. This preS1 fragment purified by anion exchange chromatography was able to bind specifically to the isolated plasma membranes from human liver. Hence, this recombinant preS1 peptide can be used to identify and isolate hepatocyte receptors for HBV.

Significance of pre-S2 protein and its antibody in children with HBV infections

Pre-S2 protein and its antibody were detected in 130 children with hepatitis B virus (HBV) infection and 30 with T6 hepatitis B (HB) vaccination. The results showed that pre-S2 was positive in most chronic persistent hepatitis (CPH) and chronic active hepatitis(CAH) patients, while anti-pre-S2 was positive in only 8% (2/92 cases) and 11.5% (3/26 cases) respectively. The positive rate of anti-pre-S2 was 78.9% (15/19 cases) in cases at the convalescent stage of acute hepatitis B, 91.7% (55/60 cases) in cases with T6 HB vaccination and 83.3% (25.30 cases) in naturally acquired anti-HBs children, while pre-S2 was not noted. Anti-pre-S2 was negatively related to ALT and positively to anti-HBs (P less than 0.01). The positive relation of pre-S2 to HBsAg was observed. These results suggest that pre-S2 could be a marker for HBV infection, and anti-pre-S2 may indicate a favourable prognosis of HBV infection. There was no correlation between anti-pre-S2 and pathogenic damages induced by HBV.

Hepatitis B virus propagated in a rat hepatoma cell line is infectious in a primate model

The human hepatitis B virus (HBV) produced by a rat hepatoma cell line through transfection with HBV DNA is infectious in the human primate model--chimpanzee. Since hepadnaviruses are known to have an extremely narrow host range, our results support the idea that the host species barrier of HBV infection resides on the penetration/adsorption step rather than any postpenetration intracellular event during the virus life cycle.

In vivo distribution of adoptively transferred indium-111-labeled tumor infiltrating lymphocytes and peripheral blood lymphocytes in patients with metastatic melanoma

Patients with metastatic melanoma undergoing therapy with cyclophosphamide (CPM), tumor-infiltrating lymphocytes (TIL), and interleukin-2 (IL-2) were studied for the ability of their 111In-labeled TIL or peripheral blood lymphocytes (PBL) to localize in sites of tumor using gamma camera imaging and biopsies. Nineteen infusions of radiolabeled TIL were given to 18 patients, while five patients received radiolabeled autologous PBL during TIL therapy. Clear tumor localization was seen on 13 of 18 nuclear scan series performed on 111In-TIL recipients, while tumor was imaged in only one of four scan sequences on patients given 111In-PBL. Nineteen paired biopsies of tumor and normal skin were completed on 10 patients receiving 111In-TIL, while eight biopsies were done on three PBL patients receiving 111In-PBL. The mean percentage of total injectate activity localizing per gram of tumor tissue was 0.0049% in the TIL group and 0.0010% in the PBL group (P2 = .0004). The mean of the tumor to normal skin ratios of the 111In-TIL group was three times that for 111In-PBL (P2 = .0072). One patient was studied by nuclear scanning on three consecutive treatment courses of CPM, TIL, and IL-2. He initially demonstrated clear tumor localization by 111In-TIL at several sites, then faint localization with 111In-PBL at a single site, and subsequently positive tumor imaging on repeat 111In-TIL infusion at multiple sites. These results confirm and expand our initial data demonstrating that human TIL transferred with CPM pretreatment and followed by IL-2 preferentially localize to tumor sites and indicate that this localization is greater for TIL than PBL.

Characterization of von Willebrand factor in factor VIII concentrates

Commercial concentrates of factor VIII (FVIII) were analyzed in order to 1) determine the effects of viral inactivation on von Willebrand factor (vWF); 2) evaluate the vWF content of the new, immunopurified concentrates; and 3) assess their potential for correcting the long bleeding time of von Willebrand disease (vWD). Included in our study were products that had been treated to inactivate viruses; older, untreated products; and the new, immunopurified concentrates. We measured von Willebrand factor antigen (vWF:Ag), ristocetin cofactor activity (RCoF), and vWF multimeric and subunit composition. A newly developed radioimmunoassay (RIA) was used to quantitate vWF:Ag. The vWF:Ag content varied from 0.083 micrograms/IU FVIII:C for Hemofil M to 32.2 micrograms/IU FVIII:C for Humate-P, whereas pooled normal human plasma (NHP) contained 6.3 micrograms/IU FVIII:C. The RCoF varied from 0.0007 to 2.09 U/IU FVIII:C, with the immunopurified concentrates having the lowest values and Humate-P the highest. The ratio of RCoF to vWF:Ag ranged from 11 to 96 U/mg, as compared to a ratio of 160 for NHP. All of the concentrates lacked the largest vWF multimers, and all had abnormal triplet patterns. Modest differences between some untreated concentrates and their treated counterparts were noted. As expected, the immunopurified concentrates had much lower levels of all vWF activities than the conventionally prepared products. Our data suggest that none of the concentrates have as great a capacity as NHP to correct the prolonged bleeding time of von Willebrand disease.

The one-child family: international patterns and their implications for the People's Republic of China

The campaign for one-child families in the People's Republic of China has created world-wide interest. This study compares the general rates of single-child families in China and in 60 other countries and shows that China's current rate (12.5) is relatively low in comparison with some developed countries, e.g. Hungary (25.0). The mean age-specific single-child rate for 54 less developed countries shows a different pattern from that for seven developed countries; this is likely to be due to the later age of marriage and longer birth intervals of women in the developed countries.

Quality of life, intellectual development and behavioural characteristics of single children in China: evidence from a 1980 survey in Changsha, Hunan Province

This paper reports the results of a June 1980 survey of 1069 children in Changsha, Hunan Province. The data have been unavailable previously either in Chinese or in English. In general, they suggest that comparisons of single children with children from multiple-child families in China regarding quality of life, intellectual development, and behavioural traits are similar to comparisons conducted in the United States and other western countries. As in many western studies, single children in China appear to have a better quality of life than children with siblings. Regarding intellectual development, single children in China perform better than those with siblings, a finding which is consonant with the family intactness model of Falbo. Single children in Changsha are little different from ones from multiple-child families on various aspects of behaviour, and are more co-operative and less hostile. These findings are the opposite of those of the Shanghai study, the other major analysis of single children in China; the Shanghai survey indicated that single children were not as well-behaved as those with siblings, a finding that caused some concern among Chinese social scientists. To the extent that the findings of the Changsha study, and not those of the Shanghai study, reflect the situation of single children in China, this could mean that the one-child family planning campaign may not be having a negative impact on children's behaviour.

Immunosuppression by cytostatic drugs?

In the present study, an attempt was made to characterize the immunomodulating abilities of the cytostatic drugs cyclophosphamide, ifosfamide, vinblastine, vincristine, procarbazine, dacarbazine, 6-mercaptopurine, methotrexate, 5-fluorouracil and adriamycin in a defined experimental model. Varying combinations of drug plus transplantation alloantigen, (C3H-lymphocytes) were injected into Balb/c mice at different time intervals in vivo. The resulting T-effector cell reactivity was determined in vitro with the microcytotoxicity assay on day +5 for primary (1 degree) and day +7 for secondary (2 degrees) sensitized mice. According to the type of drug (alkylating agent vs. vinca alkaloid vs. antimetabolite vs. cytostatic antibiotic), the dosage (20% LD50 vs. 60% LD50), the state of sensitization (1 degree vs. 2 degrees sensitized recipients), and the time of drug application in relation to the antigen treatment on day 0 (in varying steps from day -6 to day +4), so-called "pharmacon-antigen-variation-effects" (PAVE) were established for each of the investigated drugs in form of reaction profiles. The results were as follows: For almost all substances, characteristic reaction profiles involving immunostimulation and/or immunosuppression could be established. Similarities in the profiles of different substances made it possible to classify the drugs according to different reaction types. The reaction type however is not definitely correlated to the biochemical mechanism of drug action. The PAVE are decisively influenced by some of the biological parameters, such as the time of drug application in relation to the antigen treatment and the state of sensitization but relatively little by the dosage of the drug. Considering the different processes occurring during primary and secondary immune responses, the PAVE may give hints for a distinct manipulation of the immunoregulation and thus information on the immunobiological mechanism of drug action.

Estimating voluntary and involuntary childlessness in the developing countries

This paper examines rates of marital childlessness in the developing countries of the world and separates them into voluntary, involuntary and related components through a decision-tree model based on fecundity, contraceptive behaviour, pregnancy status, age, years married, and other variables. The principal data are taken from World Fertility Surveys. The conclusion is reached that virtually all of the permanent childlessness in the developing countries examined is involuntary.

Effects of 12-0-Tetradecanoylphorbol-13-acetate (TPA) on rat pheochromocytoma (PC12) cells: interactions with epidermal growth factor and nerve growth factor

The phorbol ester tumor promotor 12-0-tetradecanoylphorbol-13-acetate (TPA) specifically inhibited the binding of radioiodinated epidermal growth factor (125I-EGF) to rat pheochromocytoma (PC12) cells in a noncompetitive fashion with an apparent Ki of 11-26 nM. Both TPA and EGF elicited similar biological responses in PC12 cells including enhanced incorporation of 3H-choline and 32 P-orthophosphate into macromolecules, induction of ornithine decarboxylase, and stimulation of the phosphorylation of a 30,000 MW nonhistone, chromosome-associated protein. These effects were also elicited by nerve growth fact (NGF) which, in contrast to the former agents, is a differentiating stimulus for PC12 cells. The effects of TPA were additive or more than additive to the effects of NGF and EGF. When PC12 cells were induced to differentiate by treatment with NGF for 72 hours, the binding of 125I-EGF and responses to EGF were reduced by approximately 70%. The response of PC12 cells to the tumor promoter TPA was unaffected by treatment with NGF. Thus, the qualitatively similar effects of TPA and EGF seemed to be mediated through separate receptor systems with only the EGF receptor system reduced by NGF treatment.

Control of adenylate cyclase from secretory vesicle membranes by beta-adrenergic agents and nerve growth factor

Adenylate cyclase [ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1] activity of purified secretory vesicle membranes from the adrenal medulla is inhibited by I-isoproterenol and I-epinephrine, as well as by nerve growth factor (NGF). The effect of these agents was found to be dose-dependent and, in the case of the catecholamines, saturable. NGF was active at concentrations as low as 10(-8) M. Oxidized NGF was only minimally active, and insulin was completely inactive. Neither dopamine nor phenylephrine had activity. Inhibition of cyclase by either isoproterenol or epinephrine was blocked by I-propranolol, a specific beta-antagonist, but propranolol by itself had no effect on adenylate cyclase activity. The data indicate that the secretory vesicle membrane has beta-adrenergic receptors coupled to the adenylate cyclase. Propranolol was also found to block the NGF-induced inhibition of cyclase. We conclude that the granule membrane has beta-adrenergic receptors as well as NGF-reactive sites, and that the two may be functionally linked.

The effect of nerve growth factor on cycle AMP levels in superior cerival ganglia of the rat

Nerve growth factor (NGF) produces a several-fold increase in the cyclic AMP concentration in rat superior cervical ganglia in organ culture within 5 min. An increase can be seen with as little as 40 ng/ml of NGF. Oxidized NGF is without effect. The increase in the cAMP concentration produced by NGF is prevented by the addition of antiserum to NGF.