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Biomedical subjects

B Wahren

Publications and source records attributed to B Wahren.

At least 271 records · Page 15Linked to original sources
PubMed1988

Neutralization capacity and antibody dependent cell-mediated cytotoxicity of separated IgG subclasses 1, 3 and 4 against herpes simplex virus.

IgG subclasses 1, 3 and 4 in sera from herpes simplex virus type 1 (HSV-1) seropositive donors were separated and their functions assayed. The main neutralizing activity to HSV-1 was found in the IgG1 fractions. Both IgG3 and IgG4 possessed higher neutralizing titres than IgG1 in relation to the respective HSV IgG subclass enzyme-linked immunosorbent assay (ELISA) titre. Addition of complement resulted in a strong enhancement of IgG3 neutralizing activity. HSV neutralizations by IgG1 and, surprisingly, IgG4 were also somewhat enhanced by complement. With the addition of complement, the contribution to neutralizing activity of IgG3 was calculated to increase from 31 to 40% of total IgG in HSV neutralization in native sera. The avidities of the IgG fractions to HSV glycoprotein C (gC) were estimated in a few sera but could not be correlated to neutralization results. Antibody dependent cell-mediated cytotoxicity (ADCC) was detectable mainly in IgG1 and 3 fractions of sera with high anti-HSV antibody titres.

Antibody Affinity↗
PubMed1988

IgG subclass response to HIV in relation to antibody-dependent cellular cytotoxicity at different clinical stages.

The anti-HIV IgG subclass response was analysed in sera from different clinical stages and related to virus specific antibody-dependent cellular cytotoxicity (ADCC). IgG1 was found to be the dominant subclass, present in all sera and with similar mean titres at different stages. The number of anti-HIV IgG3 positive sera, measured on whole viral lysate antigen plates, decreased during disease progression from 38% in symptom-free to 7% in AIDS patients. IgG2 and IgG4 subclasses were less prevalent although a slight increase of IgG4 frequency was found in AIDS patients. High IgG1 titres correlated with a positive ADCC reaction but there was no correlation between anti-HIV IgG1 and ADCC titres. Some sera which contained HIV IgG1 as the only subclass were able to mediate an ADCC reaction. In addition, when anti-HIV IgG3 was isolated, by protein A chromatography, no ADCC killing was induced by these antibodies. It is concluded that IgG1 is the major ADCC-active IgG subclass in HIV infected individuals. The lack of correlation between IgG1 and ADCC titres may be explained by a relatively small fraction of IgG1 antibodies mediating ADCC.

AIDS-Related Complex↗
PubMed1987

Patterns of seminoma tissue markers and deletions.

Seminomas and control tissues were analyzed for several tumor markers. Very high levels of placental alkaline phosphatase (PLAP)-like enzyme levels were found in all 18 seminomas studied. The majority of the seminomas were of phenotype I, thus differing from palcental PLAP. The mean amount of enzyme protein as measured by monoclonal antibodies, was 100 times higher than in non-malignant tissues and 10 times lower than in placental tissue. The specific enzymatic activity in seminomas was about half of that observed in placenta. Similarly, the specific activity of PLAP-like enzymes in sera of patients with seminoma was only about half of that found in pregnancy sera. HCG was strongly elevated in 3 seminomas, but not obviously related to PLAP. Thirteen of the 17 pure seminomas had HCG over 100 IU/g, which was not seen in normal testes. Liver alkaline phosphatase (LAP) and intestinal alkaline phosphatase (IAP) were high in seminomatous tissues, the mean increases being 60-fold and 20-fold, respectively. The highest IAP levels were found in 2 yolk-sac tumors. Ferritin was moderately elevated in seminomas, but high in several control tissues. Carcinoembryonic antigen (CEA) was not elevated and alpha-fetoprotein (AFP) was not detected at all in pure seminomas. A decrease in carbohydrate antigen 50 (CA-50) content was noted in seminomas as compared to normal testes, yolk-sac tumors and choriocarcinomas. Defects in tumor-related enzymes may account for increase of PLAP and decrease of CA-50.

Alkaline Phosphatase↗
PubMed1987

Subclass reactivity to Epstein-Barr virus capsid antigen in primary and reactivated EBV infections.

A new method for analysis of virus-specific Immunoglobulin G (IgG) subclasses was developed using indirect immunofluorescence. Three hundred thirty-three serum samples from patients with different types of Epstein-Barr virus (EBV)-associated diseases and healthy controls were examined for subclass distribution to the virus capsid antigen (EBV VCA). EBV-VCA-expressing cell preparations were incubated with patient serum followed by monoclonal antibodies to human IgG1 through IgG4 and labelled anti-mouse IgG. Virus-specific IgG1 was found to be the dominant antibody. The titers for IgG1 and total Ig to EBV VCA correlated well. EBV VCA-specific IgG2 was not found. EBV VCA-specific IgG3 in a titer of greater than or equal to 10 was found in 33% of healthy seropositive donors, in 97% of patients with suspected reactivated EBV infection, and in 100% of symptomatic patients with suspected reactivated EBV infection. EBV VCA specific IgG3 occurred in 90% of placebo-treated compared to 30% in long-term acyclovir-treated bone marrow transplant recipients, indicating more frequent reactivations in the former group. IgG4 to VCA was infrequently found in seropositive persons. In serum samples from patients with nasopharyngeal carcinoma and high EBV VCA Ig and IgA titers, IgG4 to VCA was always present. Analysis of EBV VCA specific IgG subclasses seems to be valuable for the diagnosis of reactivated EBV infection.

Adolescent↗
PubMed1987

Monocyte and iscom enhancement of cell-mediated response to cytomegalovirus.

Cell-mediated and humoral responses to cytomegalovirus were studied in a monkey model. Repeated low doses of virus antigen gave poor reactivities in both respects. High antigen doses gave a good humoral IgG response. When autologous monocytes were incubated with the CMV antigen as the immunizing injection, the specific cellular response to CMV antigen increased. The monocytes themselves did not contribute to the in vitro specific proliferation response. When iscoms were the carrier particles for CMV antigens, cellular response was even more strongly enhanced. In immunization schedules where specific cellular responses are important, we suggest that autologous monocytes or iscoms may be employed as antigen carriers.

Animals↗
PubMed1987

Inhibiting effect of (RS)-9-[4-hydroxy-2-(hydroxymethyl)butyl]guanine on varicella-zoster virus replication in cell culture.

The activity and mode of action of the new nucleoside analog (RS)-9-[4-hydroxy-2-(hydroxymethyl)butyl]guanine (2HM-HBG) against varicella-zoster virus (VZV) were determined. In cell culture, replication of different strains of VZV was inhibited to 50% by 0.4 to 0.7 microM 2HM-HBG, while 685 microM was required to inhibit 50% of the DNA synthesis in uninfected human lung fibroblasts. A thymidine kinase-negative VZV strain was not inhibited by 100 microM 2HM-HBG. Inhibition of VZV replication was not reversible after 7 to 14 days of incubation, depending on the multiplicity of VZV. 2HM-HBG was shown to be selectively phosphorylated by purified VZV thymidine kinase, with an inhibition constant of 32.5 microM. The antiviral activity of 2HM-HBG in cell culture was decreased by the addition of deoxythymidine and deoxycytidine but not by other ribo- or deoxyribonucleosides.

Antiviral Agents↗
PubMed1987

Acyclic guanosine analogs as inhibitors of human cytomegalovirus.

The acyclic guanosine analogs R- and S-enantiomers of 9-(3,4-dihydroxybutyl)guanine [(R)- and (S)-DHBG], 9-(4-hydroxybutyl)guanine (HBG), and 9-(2-hydroxyethoxymethyl)guanine (ACV) were examined for their effects on human cytomegalovirus (CMV) replication and on CMV DNA synthesis in cell culture as well as for their ability as triphosphates to interact with CMV DNA polymerase. Production of early CMV antigens was not affected. All analogs inhibited CMV DNA synthesis and late viral antigen synthesis. Primary CMV isolates were less susceptible to all tested analogs than was the laboratory strain CMV Ad.169. The triphosphate of ACV was the most potent inhibitor of CMV DNA polymerase, with an observed Ki of 0.0076 microM. The corresponding Ki values of the triphosphates of (R)-DHBG, (S)-DHBG, and HBG were 3.5, 13.0 and 0.23 microM, respectively. All triphosphates of the analogs given above inhibited CMV DNA polymerase in a competitive manner with respect to dGTP. The triphosphates of the analogs also inhibited reactions when the synthetic template poly(dC)oligo(dG)12-18 was used, whereas no inhibition was observed with poly(dA)oligo(dT)12-18. None of the triphosphate analogs supported DNA synthesis in the absence of dGTP, showing that no analog was an alternative substrate to dGTP.

Acyclovir↗
PubMed1987

Characteristics of the specific cell-mediated immune response in human immunodeficiency virus infection.

The human immunodeficiency virus (HIV)-specific lymphocyte proliferation response was determined for 40 persons at different stages of HIV infection. The specific response to purified HIV virion antigens from strain HTLV-IIIB was poor, occurred in only 9 of the 40 subjects, was not improved with the addition of interleukin-2, and was more frequent in symptom-free individuals (46%) than in patients with lymphadenopathy syndrome (10%). Reactivity to subcomponent p24 was better than that to whole HIV; reactivity was present in five of six infected persons and increased with the addition of exogenous interleukin-2. Reactivities to subcomponents (g)p41 and gp120 were also measured. This is the first evidence of a specific cell-mediated immune response to HIV antigen in HIV-infected persons. Monkeys immunized with purified HIV or with purified p24 displayed cellular immunoreactivity both to whole HIV and to subcomponents. In contrast to the poor reactivity to HIV antigen, the lymphocytes of the patients had good specific cell proliferation responses to cytomegalovirus and herpes simplex virus challenge and a normal response to the addition of phytohemagglutinin. The results suggest a functional defect in peripheral lymphocytes of some HIV-infected individuals on the basis of their response to whole HIV antigen and a better response to gag protein.

AIDS-Related Complex↗
PubMed1987

Evaluation of gastric carcinoembryonic antigen analysis as an aid during screening for gastric neoplasia in atrophic gastritis.

The value of gastric juice and tissue carcinoembryonic antigen (CEA) analysis as an adjunct to endoscopic screening for gastric neoplasia was investigated in 61 patients with atrophic gastritis of whom 41 had other (superimposed) gastric lesions: six adenocarcinoma, four carcinoid, 23 regenerative polyps with or without dysplasia and eight fundic, or antral mucosal dysplasia. The gastric concentration of CEA did not differ between patient groups with different superimposed lesions. In these patients the gastric juice CEA concentrations were significantly increased in comparison with those in patients without superimposed lesions (p = 0.002). Gastric juice CEA concentrations above the upper range (+2SD) of those observed in normal controls were found in 40 (98%) of 41 patients with superimposed lesions and in 13 (65%) of 20 patients without such lesions (p = 0.001). At re-examination of 26 patients without neoplasia initially, after a mean interval of 32 months two (without polyps initially), had developed regenerative polyps, one an adenoma, and one an adenocarcinoma. These four had raised gastric juice CEA concentrations at the initial examination.

Adult↗
PubMed1987

Failure to prevent cytomegalovirus infection by cytomegalovirus hyperimmune plasma: a randomized trial by the Nordic Bone Marrow Transplantation Group.

Bone marrow transplantation recipients who were cytomegalovirus (CMV) seropositive and/or had a CMV seropositive donor were randomized for treatment with CMV hyperimmune plasma (n = 27) or no treatment at all (n = 27). The CMV hyperimmune plasma had neutralization titers greater than 250 and enzyme-linked immunosorbent assay titers greater than 18,000. Plasma (200 mg/kg body weight) was given on four occasions (during 2 days) from day 3 to day 76 after transplantation. Patient characteristics were similar in the two groups. After transplantation, the median CMV titers increased with greater than 100% in the group receiving the CMV plasma and decreased to less than 50% in the controls (p less than 0.01). Asymptomatic CMV infections occurred in 26% of the patients in the plasma group and 33% of the controls. The frequency of patients with symptomatic CMV infections was also the same in the two groups (51% vs 33%). Three patients each in the two groups developed CMV-associated interstitial pneumonitis. Patient survival and causes of death were similar in the two groups. To conclude, no beneficial effect of CMV hyperimmune plasma was seen in patients at high risk of developing CMV infections.

Antibodies, Viral↗
PubMed1986

Clinical significance of A, B, H isoantigen deletion of urothelial cells in bladder carcinoma.

The occurrence and/or deletion of A, B, H isoantigens in cytologic specimens was compared to a number of other clinical parameters commonly used for prediction of prognosis or monitoring of bladder carcinoma. Isoantigens were better preserved by our preparation for cytologic than for histologic specimens. Patients with isoantigen present on urothelial cells were more likely to have small or no visible tumors than large tumors. A strong correlation was found between isoantigen status and cytologic diagnosis (P less than 0.001), but not with ploidy (P = 0.059). For short-term prognosis of recurrence, tumor size appeared to be highly significant, whereas A, B, H isoantigen determinations had no predictive value. Intravesical chemotherapy did not per se influence expression/deletion of isoantigens.

ABO Blood-Group System↗
PubMed1986

Phenotypes of placental-type alkaline phosphatase in seminoma sera as defined by monoclonal antibodies.

PLAP-like enzymes could be detected in serum of patients with primary testicular tumors, in particular seminomas. The use of a panel of monoclonal antibodies (MAbs) permitted typing into 6 different testicular serum phenotypes, of which one appeared similar to a placental type (II) and 2 have not been previously described. Most tumor sera belonged to type I, as described for seminoma tissues. With a more advanced tumor the mean serum PLAP-like levels increased. After operation, after radiotherapy or with no evidence of disease lower or non-detectable enzyme levels were found. In typing the tissue PLAP-like antigen in serum of the same patient or sera from recurrences of a seminoma in the same patient, the same phenotypes of PLAP-like antigen were usually but not always found. None of the 6 phenotypes appeared to confer a poorer prognosis. We conclude that the expression of PLAP-like antigen is eutopic and is enhanced by testicular malignancy, especially in seminoma cells.

Adult↗
PubMed1986

Potential ganglioside antigens associated with human gliomas.

Gangliosides in human gliomas were investigated and found to have an altered composition and concentration as compared to normal grey and white matter of brain. The major gangliosides GM1, GD1a, and GT1b were markedly reduced in the tumour tissue and in contrast there was an increase of gangliosides GM3 and GD3, which often appeared as the dominating ones. Moreover, the tumours contained gangliosides, both mono- and oligosialylated, which could not be detected in the normal brain. The concentration of gangliosides, 0.7 +/- 0.4 mumol sialic acid/g, was significantly lower as compared to normal brain grey (p less than 0.001) and white matter (p less than 0.01), which contained 3.5 +/- 0.3 and 1.2 +/- 0.3 mumol sialic acid/g respectively. The tumour tissue concentration of phospholipids was 14 +/- 8 and of cholesterol 19 +/- 12 mumol/g. The appearance in glioma tissue of gangliosides that are not found in normal brain tissue suggests that these are tumour associated and might serve as surface antigens detectable by specific monoclonal antibodies.

Adult↗
PubMed1986

Clinical and subclinical reactivations of varicella-zoster virus in immunocompromised patients.

The frequencies of reactivated disease due to varicella-zoster virus (VZV) in immunocompromised patients were determined by enzyme-linked immunosorbent assay for antibody and also by the lymphocyte proliferation response to VZV antigen. Subclinical reactivations were as common as classical herpes zoster in all patient groups. Among bone marrow transplant (BMT) recipients, 36% developed herpes zoster and 26%, a subclinical reactivation. The corresponding frequencies for patients with leukemia during induction therapy were 5% and 10%; in renal transplant recipients, 0% and 26%; and in patients with seminoma, 0% and 6%, respectively. Subclinical reactivation of VZV thus appears to be a common finding in severely immunocompromised patients. A regained lymphocyte proliferation response to VZV antigen is a sensitive indicator of subclinical reactivation of VZV in BMT recipients. None of 19 BMT recipients with subclinical disease due to VZV later developed clinical reactivation of VZV. Acyclovir given as prophylaxis against infection with herpes simplex virus reduced the number of clinical and subclinical reactivations of VZV during treatment in BMT recipients, but not thereafter.

Acyclovir↗
PubMed1986

Pharmacokinetics, safety and preliminary clinical experiences using foscarnet in the treatment of cytomegalovirus infections in bone marrow and renal transplant recipients.

Fifty seven episodes of severe cytomegalovirus (CMV) infection were treated with iv foscarnet in 13 bone marrow and 33 renal graft recipients. The ranges of the daily dose, duration, average steady state level and total dose were 23-268 mg/kg, 2-46 days, 42-400 mg/l and 2-399 g, respectively. Adverse effects, such as decreased haemoglobin, decreased renal function and increased serum calcium, were observed in a few patients only. Increased liver enzymes, hallucinations and tremor were seen in one uraemic patient and coincided with foscarnet plasma concentrations above 400 mg/l. Among 25 patients evaluated for clinical efficacy, 12 died. Improvements, such as eradication of CMV (8/14 assessable patients), resolution of fever (11/22), and improved laboratory values (13/23) were noted in 17/24 (70%). Controlled trials are warranted on the basis of this study.

Adult↗