[Establishment and application of serologic diagnosis method in human immunodeficiency virus]

Using immunoenzymatic method (IE) for human immunodeficiency virus type 1 (HIV-1) serologic detection, and comparing with indirect immunofluorescence method (IIF). This method had same specificity and reproducibility but more sensitivity than IIF. Because it is simple, practical and suitable, IE method can replace IIF as the HIV serologic screening method suited to base application. Using HIV-1 immunoenzymatic reagent kit in Ivory Coast obtained good results.

[Establishment of hybridoma cell lines producing monoclonal antibodies against-p30 antigen]

BALB/c mice were immunized with the purified p30 antigen. SP2/0 myeloma cells and immune spleen cells were fused with 50% PEG (Sigma, MW 3,350-4,000). The cell fusion rate was 93.95%, and the antibody producing rate 21.01%. The technique of limiting dilution was used for cloning of the hybridoma cells. Two hybridoma cell lines E8 and G1 secreting McAb against p30 antigen were obtained. The number of chromosome of both E8 and G1 cell lines was 98.7 +/- 6.54 and 97.7 +/- 7.77, respectively. Results of the PAGE of the ascites generated by the hybridoma cell lines E8 and G1 showed a thick protein band at the gamma-region which was absent from the ascites generated by the SP 2/0 myeloma cells. The immunoglobulin of the McAb E8 and G1 belonged to IgG2 subclass. The results of the immunohistochemical method using the horseradish peroxidase conjugated antibody showed that both E8 and G1 McAb only reacted with epithelial cells of the normal human prostatic glands and their ducts, but did not cross-react with other thirty-four different kinds of normal human tissues. The results of inhibiting ELISA test showed that both E8 and G1 McAb were only inhibited by the human seminal plasma and p30, weakly inhibited by the adult male's urine, but were not inhibited by other eight different kinds of human body fluids and secretions as well as semen from eight different species of animals. It was concluded that McAb of E8 and G1 were organ and species specific.(ABSTRACT TRUNCATED AT 250 WORDS)

Volatile nitrosamine levels and genotoxicity of food samples from high-risk areas for nasopharyngeal carcinoma before and after nitrosation

Traditional life-style, especially food habits, infection by Epstein-Barr virus (EBV) and genetic factors, have been associated with an increased risk of nasopharyngeal carcinoma (NPC). N-Nitroso compounds and other carcinogens either present in food or formed endogenously, as well as food constituents that activate EBV, have been suspected as etiological factors in NPC pathogenesis. For their characterization preserved food items, frequently consumed in NPC endemic areas in Tunisia, South China and Greenland, were sampled and screened for the presence of mutagens and volatile nitrosamines before and after nitrosation. Aqueous extracts as well as 2 organic extracts of the samples were assayed for genotoxicity in 2 Salmonella typhimurium strains and the SOS chromotest. The same extracts had previously been analyzed for volatile nitrosamines and for EBV-activating substances in Raji cells. In our study, 13 out of 16 food samples showed a weak, directly-acting genotoxicity in the SOS chromotest in at least one of the extracts, but only one sample from Greenland was found to be weakly mutagenic in Salmonella TA 98. Chemical nitrosation for 9 out of 15 samples of aqueous food extracts increased the genotoxic effect in the SOS chromotest. Levels of volatile nitrosamines were also elevated for 12 out of 15 samples; highest levels of N-nitrosodimethylamine were found in hard salted and dried fish from China (1,200 micrograms/kg) and highest N-nitrosopyrrolidine levels in a Tunisian spice (3,840 micrograms/kg). In non-nitrosated aqueous food extracts, the level of volatile nitrosamines and genotoxic activities were not correlated with the EBV-inducing activity of the same samples. After chemical nitrosation, EBV-inducing activity was decreased or showed no change and was not correlated with increases in either the genotoxicity or the nitrosamine levels. Our results suggest that EBV-activating compounds belong to a different class of substances. However, there was an association between the changes in genotoxicity and nitrosamine levels due to nitrosation.

Clinical analysis of four Chinese hemophiliacs with human immunodeficiency virus infection

Human immunodeficiency virus (HIV) is now considered as the causative agent of acquired immunodeficiency syndrome (AIDS). A high risk of AIDS has been reported among patients with hemophilia who received lyophilized commercial factor VIII and IX concentrates of American origin. At a prevalent survey from September to December 1985, HIV antibodies were found in all four patients with hemophilia treated with the batch number W87307, 955 I.U. of American commercial factor VIII concentrate supplied by Armour Pharmaceutical Company, USA. One of the sero-positive patients developed AIDS-related complex (ARC) and died of cerebral hemorrhage. The other three sero-positive patients had abnormalities in cell-mediated immunity. Of them two developed left lumbosacral radiculopathy and hemorrhagic herpes zoster and one remained well so far.

Pleiotropic resistance to glycoprotein processing inhibitors in Chinese hamster ovary cells. The role of a novel mutation in the asparagine-linked glycosylation pathway

In order to obtain a better understanding of the control mechanisms involved in asparagine-linked glycosylation, we developed conditions under which the glucosidase I and II inhibitor castanospermine and the mannosidase II inhibitor swainsonine were toxic to Chinese hamster ovary (CHO) cells when cultured in the presence of low concentrations of the plant lectin concanavalin A. Cells resistant to castanospermine (CsR cells) and swainsonine (SwR cells) were obtained by gradual stepwise selections. These cells had normal levels of glucosidase II and mannosidase II and appeared to have no major structural alterations in their surface asparagine-linked oligosaccharides. Interestingly, the CsR and SwR cells were each pleiotropically resistant to castanospermine, swainsonine, and deoxymannojirimycin, an inhibitor of mannosidase I. This resistance was not due to the multiple-drug resistance phenomenon. Both the CsR and SwR cell populations synthesized Man5GlcNAc2 in place of Glc3Man9GlcNAc2 as the major dolichol-linked oligosaccharide. This defect was not due to a loss of mannosylphosphoryldolichol synthetase. Furthermore, the Man5GlcNAc2 oligosaccharide was transferred to protein and appeared to give rise to normal mature oligosaccharides. Thus, the CsR and SwR cells achieved resistance to castanospermine, swainsonine, and deoxymannojirimycin by synthesizing altered dolichol-linked oligosaccharides that reduced or eliminated the requirements for glucosidases I and II and mannosidases I and II during the production of normal asparagine-linked oligosaccharides. We propose that this phenotype be termed PIR, for processing inhibitor resistance.

Epstein-Barr virus activation in Raji cells by extracts of preserved food from high risk areas for nasopharyngeal carcinoma

Epstein-Barr virus (EBV) activation of latent infection and traditional life styles, especially food habits, have been strongly associated with an increased risk of nasopharyngeal carcinoma (NPC) in humans. On the basis of anthropological studies in Tunisia, southern China and Greenland, extracts of representative preserved food items consumed frequently by the high-risk populations for NPC were assayed for the presence of EBV activators in Raji cells. A strong EBV activation activity was observed in aqueous extracts of some Cantonese salted dried fish from China, harissa (a spice mixture) and to a lesser extent qaddid (dry mutton preserved in olive oil) from Tunisia. These new data may support epidemiological evidence for the importance of Cantonese salted and dried fish and other food items in the etiology of NPC.

Wikstroemia indica promotes development of nasopharyngeal carcinoma in rats initiated by dinitrosopiperazine

Nasopharyngeal carcinoma was induced in an initiation/promotion model in rats by s.c. injection of dinitrosopiperazine in the nasopharyngeal cavity. This was followed by repeated 10-cal administration of an extract of roots of the Chinese medicinal herb WI (botanical family: Thymelaeaceae). Three groups of rats were used: group-1 received DNP followed by repeated WI; group-2 received DNP once; group-3 received WI repeatedly. At 180-205 days after DNP + WI administration 26% of the rats in that group exhibited NPC (two were carcinomas in situ and four were early infiltrating carcinomas). In the other two groups no carcinomas were found. In the group which received DNP followed by WI, other pathological changes, such as hyperplasia of nasopharyngeal epithelium, squamous metaplasia, and papillary hyperplasia, were also more frequent than that in the other two groups.

[Immunofluorescent localization of associated antigen of anti-human nasopharyngeal carcinoma cell monoclonal antibody]

The immunofluorescent localization of associated antigen of anti-human nasopharyngeal carcinoma (NPC) cell monoclonal antibody (McAb) was performed in different tissues (NPC, non-NPC tumor, chronic inflammation of nasopharyngeal mucosa, adult normal tissue and embryo tissue) with 5 control experiments. McAb (CN-1, Cs-C1) was produced by Department of Microbiology of our college and all the specimens were confirmed by pathology. The results revealed that Cs-C1 antigen was mainly found on the surface of NPC cells with a positive rate of 80.3%. Majority of the positive cells showed yellow-greenish linear fluorescence surrounding the cell membrane while some cells manifested granular fluorescence. In addition, Cs-C1 antigen was also found in a few embryo tissues, epithelial cells of the normal gastric mucosa and cells of the gastric cancer. It is suggested that Cs-C1 antigen be a kind of molecular structure, being gradually produced or increased in quantity during carcinogenesis, and belong to the tumor associated antigen. Cs-C1 antigen could be important in the study of carcinogenic mechanism of NPC cells and valuable to clinical immunodiagnosis.

[Promoting effect of the Chinese medicinal herb, wikstroemia chamaedaphne and tung oil extracts on carcinoma of the uterine cervix induced by HSV-2 or methylcholanthrene (MCA) in mice]

The promoting effect of the Chinese medicinal herb, Wikstroemia chamaedaphne and Tung oil extracts (WC and HHPA) on carcinoma of uterine cervix induced by HSV-2 or MCA in mice was studied. The results showed that WC and HHPA extracts were not carcinogenic themselves. After carcinogen HSV-2 and MCA treatment, WC and HHPA were added separately. The inducing rates by HSV-2 increased from 7.4% to 21.1% and 26.3%, those by MCA increased from 56.5% to 82.8% and 84.4%. There was a significant difference between the combined groups and groups with HSV-2 or MCA only. The experimental results suggest that these two kinds of extracts play a promoting effect on carcinogenesis. The relation between the carcinogenesis of uterine cervix or nasopharynx and WC or HHPA extracts is discussed.

Evaluation of monoclonal antibodies for the detection of exfoliative nasopharyngeal carcinoma cells

Exfoliative cells were aspirated from 15 patients suspected of having nasopharyngeal carcinoma (NPC) and showing the presence of lesions or other abnormalities in the nasopharynx. They were tested for binding with a 125I monoclonal antibody (MAb) (MA6) which is selectively reactive against human B lymphocytes and a variety of carcinomas. A positive result was obtained from 6/9 patients with, and from 0/5 patients without, histologically confirmed disease. One patient with eskimoma also gave a negative binding result. Cytology was specific but less sensitive, tumour cells being detected in 3 of the patients with confirmed disease. Immunocytology using MA6 was limited, like cytology, by poor recovery of the tumour cells and the results were in complete concordance with cytology. The other MAbs used were raised against carcinoembryonic antigen (CEA) and a carcinoma cell line (Ca2), respectively. The latter was not reactive against the NPC tumour cells while the CEA antibody was not sufficiently selective to be useful.

Detection of IgA antibody to EBV membrane antigen using Staphylococcus aureus preabsorbed sera is closely associated with nasopharyngeal carcinoma

The presence of IgA antibody to membrane antigen (MA) of Epstein-Barr virus (EBV) was tested in sera from 48 nasopharyngeal carcinoma (NPC) patients, 40 patients with tumors other than NPC and 46 normal individuals. The sera were preabsorbed with Staphylococcus aureus (SPA) (strain no. 1800) prior to their use in the indirect immunofluorescence test. One hundred percent of the NPC patients had the IgA/MA antibody with a GMT of 1:141. In patients with tumors other than NPC or normal individuals, IgA/MA antibodies were not detectable. The IgA/MA antibodies have been demonstrated in 6 NPC patients lacking detectable antibody levels in the indirect immunofluorescence test using nonabsorbed sera. Our data indicate that preabsorbtion of sera with SPA renders the diagnostic test significantly more sensitive for the detection of the nasopharyngeal carcinoma and can be used for trials on the prognosis of patients.

Detection of antibody to LAV/HTLV-III in sera from hemophiliacs in China

Using ELISA, Western blots and immunofluorescence techniques, we identified seropositivity for lymphadenopathy-associated virus/human lymphotropic virus-III (LAV/HTLV-III) in 4 of 18 hemophiliacs and 1 AIDS patient. The four seropositive patients had received factor VIII prepared by Armour Company. The hemophiliacs are all asymptomatic. Given this documentation of introduction of LAV/HTLV-III into China, a national surveillance program is underway.

Epstein-Barr virus seroepidemiology in China

Since 1978 more than 300,000 sera from normal individuals were screened serologically in NPC high risk areas and prospective studies were carried out. Many patients were diagnosed in early stage. For example, in Wuzhou city, 20,726 persons over 40 years of age were screened; 1,138 persons were found to have IgA VCA antibody. Among them 18 NPC cases were detected; an additional 21 NPC patients were found within 5 year follow-up studies. Altogether there were 39 NPC patients. As compared to the patients in outpatient clinics, the frequency of NPC in stage I increased from 1.7% to 38.5% and in early stage (I + II) increased from 32% to 92.3%. IgA VCA antibody can be detected 5 years before the diagnosis of NPC in early stage was made. The detection rate of NPC from IgA VCA antibody-positive persons is 38-374 times the incidence rate of NPC in the general population of the same age group. Follow-up studies on the change of IgA VCA antibody titer in antibody-positive and antibody-negative groups were also carried out for years. 10.9% of antibody-positive individuals became antibody negative and 5.4% seronegative persons converted to positive within 4 years. Eighty-eight per cent of NPC patients were detected in the group of no change of antibody titer or in the group of increasing antibody titer. No NPC patients were found in the original antibody negative group.

Detection of IgG and IgA antibodies to Epstein-Barr virus membrane antigen in sera from patients with nasopharyngeal carcinoma and from normal individuals

IgG and IgA antibodies to Epstein-Barr virus (EBV) membrane antigen (MA) were detected in sera from 96 NPC patients and normal individuals by the indirect immunofluorescence test. For MA/IgG antibody, 100% of NPC patients were positive with a GMT of 1:439.7 and 97.9% of normal individuals were positive with a GMT of 1:94.7. In contrast, for MA/IgA antibody, 58.3% of NPC patients were positive with a GMT of 1:7.3 and none of the normal individuals were positive. There was no difference in the detection of antibodies to EBV MA when other P3HR-1 or B95-8 cell lines, differing in their major membrane antigen, were used.

Prospective studies on nasopharyngeal carcinoma in Epstein-Barr virus IgA/VCA antibody-positive persons in Wuzhou City, China

A serological mass survey was carried out in Wuzhou City in 1980, 1,136 IgA/VCA-positive persons being followed up for 4 years. Altogether 35 NPC cases were detected, of which 15 (43%) were in stage I and 17 (48.5%) in stage II, early cases (I + II) thus amounting to 91.5%. The detection rate of early cases was 2.9 times higher than in our outpatient clinic. IgA/VCA antibody could be detected 16-41 months prior to clinical diagnosis of NPC. We conclude that, if IgA/VCA-positive individuals are examined routinely once a year, NPC can be detected in the early stages of evolution. The annual detection rate of NPC in IgA/VCA antibody-positive individuals was 31.7 times higher than that of the annual incidence of NPC in the general population in the same age group, while during the 4-year follow-up period the incidence was 7.5 times higher than in the general population for the same age group. These results further indicate that EB virus plays an important role in the development of NPC, and that serological screening and follow-up studies are valuable for the early detection of NPC.