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J Hilfenhaus

Publications and source records attributed to J Hilfenhaus.

At least 37 records · Page 2Linked to original sources
PubMed1989

Preclinical investigations of the safety, immunogenicity and efficacy of a purified, inactivated tick-borne encephalitis vaccine.

A new tick-borne encephalitis (TBE) vaccine for human use has been developed. TBE virus (TBEV) was propagated in primary chick embryo cells, inactivated by formalin and purified by continuous-flow density gradient centrifugation. The TBE vaccine was tested for innocuity, immunogenicity and protective capacity in a series of laboratory tests. The results indicated that the vaccine is outstandingly well tolerated, highly immunogenic in various laboratory animals, and induces protective immunity in mice. These data suggest that this new vaccine should be studied in clinical trials.

Animals↗
PubMed1988

Inactivation of AIDS-causing retroviruses by the manufacturing procedures for human plasma proteins.

Human retroviruses causing AIDS (HIV) may occur in human plasma. Since HIV contaminated plasma cannot be completely excluded by testing for anti-HIV, AIDS safety of human plasma products can only be achieved by introducing HIV inactivating and/or eliminating methods into the manufacturing procedure. Here we review a number of methods used when manufacturing plasma derivatives at Behringwerke. These methods were previously developed either to produce a protein of required purity or to manufacture hepatitis safe products. Methods used to produce purer proteins are ethanol fractionation, pepsin treatment, affinity chromatography or various protein precipitation procedures. The method developed at Behringwerke for inactivating infectious viruses in plasma protein preparations not destroying the biological activities of the human protein is pasteurization, i.e. 10 h heat treatment of the aqueous protein solution at 60 degrees C. To investigate the HIV inactivating efficiency of the methods mentioned above, aliquots of an infectious HIV type 1 concentrate were added to a protein preparation, the resulting HIV spiked preparation treated according to the method to be studied and the amount of infectious HIV in this preparation determined before and after treatment. By all methods reported on here the HIV type 1 isolate was completely inactivated resulting in high inactivation factors. In addition, the heat stability of HIV type 2 was tested in aqueous solution at 60 degrees C proving that both HIV-1 and HIV-2 isolates are of comparably low heat stability under these conditions. From the results discussed here it can be concluded that all commercial human protein products of Behringwerke derived from either human plasma or placenta do not contain any infectious retrovirus causing AIDS and thus have a high margin of safety regarding the transmission of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1987

A strategy for testing established human plasma protein manufacturing procedures for their ability to inactivate or eliminate human immunodeficiency virus.

The manufacturing procedures used for the preparation of human plasma proteins that were established before AIDS was first described may reasonably be expected to provide AIDS safe products. Such manufacturing procedures are heat treatment at 60 degrees C in solution for ten hours, described as pasteurization, preparation of human immunoglobulins by ethanol precipitation, pepsin treatment, and sulfonation. To test whether these methods effectively inactivated and/or eliminated the AIDS causing human immunodeficiency virus (HIV), nine volumes or more of plasma or a plasma fraction taken from a production lot were spiked with HIV using one volume of a HIV concentrate and were then subjected to exactly the same procedure as that specified for the manufacturing process. HIV infectivity titres of the initial HIV/plasma protein mixtures and of the resulting products after treatment were determined by the H9 cell assay. In all cases studied complete inactivation/elimination of the added HIV was achieved. We therefore conclude that pasteurization of human plasma proteins or the manufacturing procedure used for the isolation of immunoglobulins from plasma pools result in final products which do not contain any infectious HIV and which are thus safe in that they cannot be vehicles for the transmission of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Combined antiviral effects of acyclovir or bromovinyldeoxyuridine and human immunoglobulin in herpes simplex virus-infected mice.

Suboptimal dosage regimens of antivirals (acyclovir or bromovinyldeoxyuridine) and human immunoglobulin have been combined in the treatment of hairless mice infected with herpes simplex virus type 1. The aim of this study was to establish how late after infection human immunoglobulin could be given to still be effective and for how long would the protective effect last. The combination of acyclovir or bromovinyldeoxyuridine with passive immunization proved additive or even synergistic depending on the time of immunoglobulin administration and the observation period after infection. When the survival rate of the mice was followed for up to 20 days postinfection, synergistic action seemed to occur with immunoglobulin given as late as 2 or 3 days after infection. When the mice were followed for up to 100 days after infection, however, it turned out that only the immunoglobulin given 4 h after infection led to a synergistic effect with the antivirals. Most of the mice subjected to combined treatment, in contrast to mice treated with the antivirals only, did not develop anti-HSV antibodies. This lack of a specific humoral immune response possibly reflects the rapid inhibition of virus replication early after challenge by the combined treatment, thus preventing the production of a sufficient amount of viral antigen in the body needed for a measurable antibody induction.

Acyclovir↗
PubMed1987

Reactogenicity and immunogenicity of the newly developed purified chick embryo cell (PCEC)-rabies vaccine in man.

Purified Chick Embryo Cell (PCEC) rabies vaccine was given to 88 healthy adults according to six different vaccination schedules. Local side effects were reported on reactivity forms after 16.4% of PCECV injections, general symptoms were recorded after 15.1% of the 292 doses administered. IgE antibodies specific for chicken proteins determined by the Radio Allergo Sorbens Test (RAST) could not be shown before and after the vaccinations. With no exception, all 88 vaccinees developed high titres of complement-fixing and neutralizing antibodies as determined by the Rapid Fluorescent Focus Inhibition Test and Serum Mouse Neutralization Test. For the first time, induction of serum interferon by PCEC rabies vaccine has been shown in man. In rabies vaccination, PCEC vaccine seems to be as effective as Human Diploid Cell Strain (HDCS) vaccine.

Adult↗
PubMed1987

Inactivation of HTLV-III/LAV, hepatitis B and non-A/non-B viruses by pasteurization in human plasma protein preparations.

Pasteurization (heat treatment at +60 degrees C for 10 hours in solution) during the production of human plasma protein preparations has proved useful 1. to inactivate a broad spectrum of viruses and 2. in combination with stabilizers to leave the nativity of the products unaffected. Their efficacy has been experimentally tested for HTLV-III/LAV, Hepatitis B and non-A/non-B viruses. The following preparations were tested: with HTLV-III/LAV: Factor VIII, Factor IX, AT III, AHC and PPSB; with Hepatitis B virus: Factor VIII, Factor XIII, AT III, PPSB and Fibrinogen; with Hepatitis non-A/non-B virus: Factor VIII and AT III.

Animals↗
PubMed1987

Virus safety of a pasteurized antithrombin III concentrate. Preclinical and clinical data.

Blood derived products carry the risk of virus transmission, especially for the hepatitis B virus (HBV), non-A/non-B virus(es) (NANBV) and human immunodeficiency virus (HIV). The precautionary measures for guaranteeing the virus safety of the pasteurized antithrombin III concentrate Kybernin HS/P are described and the efficacy of these measures is demonstrated by in vitro studies and by chimpanzee trials. The inactivation rate is greater than or equal to 10(6.7) for HIV, greater than or equal to 10(6.7) for HBV, and greater than or equal to 10(5.3) for NANBV (Hutchinson Pool). Clinically, virus safety was demonstrated by long-term drug surveillance as well as by both a retrospective and prospective clinical trial. The 13 participants of the prospective study were checked clinically and biochemically according to the standards of the International Committee of Thrombosis and Hemostasis (ICTH). Within an observation period of 12 months, no seroconversion has been detected for HIV or HBV. Neither have any increases in the transaminases occurred which would indicate NANB hepatitis.

Alanine Transaminase↗
PubMed1986

Inactivation of the AIDS-causing retrovirus and other human viruses in antihemophilic plasma protein preparations by pasteurization.

Heat treatment at 60 degrees C for 10 h in solution (pasteurization) was introduced into the manufacturing process of antihemophilic cryoprecipitate (AHC) and factor VIII concentrates (F VIII) to reduce the risk of transmission of hepatitis to hemophiliacs. Since the acquired immunodeficiency syndrome (AIDS) may also be transmitted to hemophiliacs by antihemophilic plasma protein preparations, we have investigated inactivation of the AIDS virus HTLV III by pasteurization in AHC or F VIII and included in this study cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV), poliovirus and vaccinia virus. Each of these viruses was efficiently inactivated by pasteurization although considerable differences were observed between the different viruses HTLV III was rapidly inactivated, becoming nondetectable within 30-60 min. Our findings indicate that pasteurized AHC or F VIII should have a high margin of safety regarding the transmission of AIDS or any other infectious disease caused by viruses such as those tested.

Acquired Immunodeficiency Syndrome↗
PubMed1986

Pasteurization as an efficient method to inactivate blood borne viruses in factor VIII concentrates.

Heat treatment at 60 degrees C for 10 h in solution (pasteurization) was introduced into the manufacturing process of factor VIII concentrate (Haemate P) in order to considerably reduce the risk of transmission of human pathogenic viruses to haemophiliacs. The results of experimental and clinical studies with regard to hepatitis B, non-A, non-B hepatitis, acquired immune deficiency syndrome (AIDS) and herpes virus infections are reviewed. From this data it is concluded that pasteurization of factor VIII results in a product which is safe with regard to these viral infections. Furthermore, it was shown that pasteurization does not form new antigenic determinants on the factor VIII molecule and compared with the native product does not alter the physiological properties of this protein in patients. In comparison to these advantageous properties of the pasteurized product a slight loss of coagulant activity seems to be acceptable. This loss of yield, however, does not influence the quality or the amount of factor VIII in the final container used for the therapy of haemophilia A patients.

Deltaretrovirus↗
PubMed1986

Generation of human anti-rubella monoclonal antibodies from human hybridomas constructed with antigen-specific Epstein-Barr virus transformed cell lines.

Human monoclonal antibodies (humab) directed against viral antigens were developed by combining immortalization of human primary B lymphocytes by Epstein-Barr virus (EBV) infection with consecutive fusion of selected immortalized lymphoblasts with an established, human lymphoblastoid cell line. Using EBV infection a high rate of immortalized B lymphoblastoid cells was obtained which unfortunately could not be cloned because at least 10 cells per microtiter well had to be seeded to get cells growing. However, fusion of these immortalized lymphoblastoid cells which had been selected for antiviral humab production with an established cell line resulted in hybridomas which could easily be cloned. Among the antiviral humab producing hybridomas thus generated, were three which produced anti-rubella humab. Rubella virus consists of three structural proteins, the core protein C and the two envelope proteins E1 and E2. By the western blot technique we were able to show that two humab reacted with the core protein and the third humab with the envelope protein E1. From the hybridomas grown in stationary cultures, highly purified humab preparations were obtained by subjecting the concentrated culture supernatant to immuno-affinity chromatography.

Animals↗
PubMed1985

Interferon-beta in patients with low-grade astrocytomas--a phase I study.

In 3 patients with low-grade astrocytomas clinical pharmacology of interferon-beta (10(7) U/mg protein) was investigated. Interferon-beta with escalating dosage (2.3, 6.9, 23, 69 X 10(6) U/patient) was given to each patient in 4 infusions at weekly time intervals. In these patients dose-dependent plasma-levels of interferon-beta of up to 5800 IU/ml were achieved. Plasma concentrations showed a biphasic decline (T1 1/2:0.095-0.49 hrs and T2 1/2: 5-14.5 hrs). Side effects were: mild fatigue, myalgia, tachycardia, hypertension, and fever; the latter was well controlled by pretreatment application of paracetamol. Hematological changes included lymphopenia (2-6 hrs after infusion) and granulocytosis (3-6 hrs after infusion). Natural Killer cell activity was also monitored: 6 hours after infusion a drop of activity - not clearly dose dependent - was observed to a minimum of 1% pretreatment activity; 24 hrs after infusion activity increased up to a maximum of 400%. In this phase I study high biological activity of interferon-beta could be detected in plasma of astrocytoma patients - clinical tolerance was good and only mild toxicity was observed.

Astrocytoma↗
PubMed1985

Safety of human blood products: inactivation of retroviruses by heat treatment at 60 degrees C.

Acquired immune deficiency syndrome (AIDS) can be transferred to patients by blood transfusions or human blood preparations, such as cryoprecipitates or factor VIII concentrates. Retroviruses have been discussed as infectious AIDS agents and more recently human T-lymphotropic retroviruses designated as HTLV type III and LAV (lymphadenopathy-associated virus) have been isolated from AIDS patients. Whether heat treatment at 60 degrees C (pasteurization) of liquid human plasma protein preparations inactivates retroviruses was therefore investigated. Pasteurization had already been included in the routine manufacturing process of human plasma protein preparations in order to guarantee safety with regard to hepatitis B. Since high titer preparations of human retroviruses were not available, heat inactivation was studied using Rous sarcoma virus added to the various plasma protein preparations tested. This retrovirus which was obtained in preparations of 6.0 log10 FFU/ml was shown to be at least as heat stable as two mammalian retroviruses studied, i.e., feline and simian sarcoma virus. In all of eight different plasma protein preparations tested, Rous sarcoma virus was completely inactivated after a heat treatment lasting no longer than 4 hr. It is thus concluded that pasteurization of liquid plasma protein preparations at 60 degrees C over a period of 10 hr must confer safety to these products with respect to AIDS, provided that the AIDS agents are retroviruses of comparable heat stability as Rous sarcoma virus and the mammalian retroviruses tested.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Long term cultivation of Namalva cells for interferon production: stable cytogenetic markers for identification of cells in spite of drastic chromosomal variation.

Namalva cells were propagated continuously over a period of up to 18 months. During this period the chromosomal status of the cell populations were investigated cytogenetically. The ability of the cells to produce interferons after induction with Sendai virus was monitored. In contrast to the drastic chromosomal variation observed, interferon production was remarkably stable. Comparison of the various cytogenetic data revealed the presence of marker chromosomes and chromosomal constellations which were excluded from the drift. Some of these are useful for unequivocal identification of Namalva cells during long term cultivation.

Cells, Cultured↗
PubMed1985

Fibrin glue safety: inactivation of potential viral contaminants by pasteurization of the human plasma components.

Fibrin glue has become an indispensable tool in salvaging operations of the parenchymatous organs of the abdomen, in vascular and ophthalmic plastic surgery as well as neurosurgery. Currently available glues contain clotting factors from human plasma and thus carry the potential risk of transmitting viral infections like hepatitis or acquired immunodeficiency syndrome (AIDS). Combined efforts in selection of plasma donations as well as pasteurization of the human plasma products allow the manufacturing of a product (Beriplast) with virtually no risk of transmission of viral infections as demonstrated by in vivo and in vitro experiments with a variety of human pathogenic viruses. No changes in activity or antigenicity of the clotting factors by the pasteurization procedure have been encountered.

Acquired Immunodeficiency Syndrome↗
PubMed1984

A new inactivated tissue culture rabies vaccine for use in man. Evaluation of PCEC-vaccine by laboratory tests.

A new inactivated rabies vaccine (purified chick embryo cell vaccine) has been developed using the Flury LEP-C 25 strain of rabies virus propagated in primary chick embryo cell cultures. The antigen was purified and concentrated by continuous density gradient centrifugation and inactivated by betapropiolactone. This vaccine was tested for innocuity, tolerability and protective capacity in a series of laboratory tests and compared with human diploid cell strain (HDC)-vaccines of similar antigenicity. The results indicated that this new vaccine was excellently tolerated and that its protective activity met the high standard of HDC-vaccine, conditions which were imposed on this vaccine before entering clinical trials in man.

Animals↗
PubMed1984

[Inactivation of viruses in Factor XIII concentrate by pasteurization].

The use of a pasteurization step (heating in solution to 60 degrees C for 10 h) makes it possible to inactivate viruses, thus increasing the safety of the preparations. Using Factor XIII concentrate solution, it can be shown that hepatitis B virus and 10 other virus species are inactivated. Pasteurized Factor XIII was produced from starting material containing a total of 10(5.7) CID50 hepatitis-B virus (10(3.5) CID50/ml; CID = chimpanzee infectious dose). This Factor XIII preparation was injected in 4 chimpanzees; they remained healthy over an observation period of 37 weeks, whereas the 2 chimpanzees that received nonheated starting material developed hepatitis B. Furthermore, Rous-sarcoma, Epstein-Barr, cytomegalo, herpes simplex, measles, and rubella virus added to Factor XIII solution are inactivated by pasteurization within 2 h, mumps virus within 8 h, and adeno, polio, and vaccinia virus within 10 h. Pasteurizing of clotting factor preparations during the manufacturing process is a suitable for inactivating viruses and thereby increasing the safety of the preparations.

Animals↗