Sensitive solid-phase immune electron microscopy double-antibody technique with gold-immunoglobulin G complexes for detecting rotavirus in cell culture and feces

A new solid-phase immune electron microscopy double-antibody colloidal-gold technique (SPIEMDAGT) was developed and compared with direct electron microscopy, direct immune electron microscopy, and enzyme immunoassay for detecting rotavirus. Guinea pig and rabbit antirotavirus antisera were used as capture and detector antibodies, respectively, and goat anti-rabbit immunoglobulin G-gold complexes were employed as a label. Animal rotavirus in cell culture media and human virus in stool specimens were detected by this method. On average, SPIEMDAGT detected 800 times more virus particles than direct electron microscopy and 45 times more particles than direct immune electron microscopy and yielded 20% more positives than enzyme immunoassay. SPIEMDAGT could detect not only viral antigen associated with morphologically recognizable particles but also antigen present when whole virus particles were not visible.

[Analysis of electromyographic findings in 37 cases of thyrotoxicosis]

The EMG findings of 100 skeletal muscles in 37 cases of thyrotoxicosis are reported. The abnormal short duration motor unit potentials occurred in 78% of examined muscles and in 45% of these muscles, the incidence of polyphasic potentials increased. These abnormalities were in agreement with myopathic lesion exactly. EMG examination is a secure and sensitive method to find impaired muscles. The wide effects of large amount of thyroxin on muscle's metabolism may result in myopathic abnormalities of EMG.

Highly efficient ultraviolet generation at 355 nm in LiB(3)O(5)

Highly efficient generation of UV radiation at 355 nm has been achieved in a LiB(3)O(5) crystal through the frequency mixing of the fundamental and second-harmonic radiation of a Nd:YAG laser. An energy conversion efficiency of 60% has been obtained under the experimental conditions described here. Thus the usefulness of LiB(3)O(5) for frequency-conversion applications is demonstrated.

[Elimination of poison from Halitum violaceum by processing]

The contents of polysulphides in different forms of Halitum violaceum (unprocessed, processed with vinegar, calcinated and boiled with water) were determined indirectly by UV spectrophotometry. The results showed that the unprocessed forms are higher in the contents of polysulphides while the processed ones have little or no such contents at all. It is thus believed that the poisons can be eliminated from Halitum violaceum by processing, which helps to decrease or eliminate polysulphides and sulphides.

Development and application of immunoassay for paraquat: radioimmunoassay

A sensitive radioimmunoassay for paraquat is reported. Anti-paraquat antisera were produced by repeated immunization in rabbits with 1-methyl, 1'-hexanoic acid-4,4'-bipyridinium (MHBP) coupled to bovine serum albumin (BSA). Less than 0.5 ng of paraquat dichloride was detectable by this assay system. These antisera were strongly cross-reactive with the bipyridyl ring and methyl group in either the 1- or 1'-position of paraquat. The determination of paraquat in tissues of paraquat-poisoned cadavers was also carried out.

Development and characterization of monoclonal antibodies reactive with paraquat

A set of three anti-paraquat monoclonal antibodies(MoAbs), named APM-1, APM-2 and APM-3, has been isolated. In order to evaluate the ability of these MoAbs to recognize various kinds of bipyridyl herbicides and similar congeners of paraquat, a competition enzyme-linked immunosorbent assay (ELISA) using avidin-biotin complex (ABC) was developed. All three antibodies strongly recognized paraquat and slightly did the other analogs. These three MoAbs are therefore advantageous to a toxicological study of paraquat and of its localization in tissues.

Immunotherapy for the treatment of acute paraquat poisoning

For the purpose of sequestering paraquat in the plasma compartment and preventing it from accumulating in tissues the effects of intravenous administration of anti-paraquat antibodies to rats were studied. After an intravenous paraquat injection of 0.1 mg/kg, the plasma paraquat concentration from rats pretreated with anti-paraquat antibodies was significantly increased and the amount of paraquat excreted in urine was significantly decreased compared to the control group. The concentration of paraquat in bile and organs except liver, was not changed by the treatment, but the paraquat level in the liver was significantly increased. Although immunotherapy succeeded in sequestering paraquat in the plasma compartment, it could not prevent paraquat from accumulating in tissues.

Relationship between methylation status and expression of an Epstein-Barr virus (EBV) capsid antigen gene

The methylation status of the 160 kD viral capsid antigen (VCA) gene promoter was determined by hybridization analysis. The semi-permissive marmoset cell line FF41-1 lacked cytosine methylation in approximately three quarters of the VCA promoter CpG dinucleotide residues. In the stringently infected HH514CL16 cell line the same CpG residues were methylated in three quarters of the genomes. 5'deoxy-5'-S-isobutyladenosine (SIBA), a DNA methylase inhibitor, was utilized to disrupt the EBV latent state. As determined by flow cytometry, SIBA treatment significantly increased expression of VCA. The VCA promoter was hypomethylated in VCA-positive FF41-1 cells sorted by flow cytometry. While hypomethylation alone was not sufficient for VCA transcriptional activity, the absence of methylation of VCA promoter CpG dinucleotide residues was associated with expression of VCA.

Retrieval of stratospheric background aerosol scattering coefficient from twilight polarization measurements

A backward Monte Carlo computation procedure has been used to simulate the intensity and degree of polarization of the twilight sky during 1977. It was found that the single scattering approximation is applicable for detection of stratospheric aerosols by twilight measurement during background periods. Based on the simulation, a scheme is proposed for retrieving the stratospheric aerosol scattering coefficient utilizing the measured degree of polarization at the 0.7-microm wavelength in the zenith direction of the twilight sky. Compared with the in situ measurement, both the retrieved total optical depth and the retrieved profile of the aerosol scattering coefficient below 30 km agree reasonably well with measurements.

Correlation of histopathological, cytological and flow cytometric findings in neoplastic and nonneoplastic lesions of the bladder

Biopsy diagnosis, urine cytology and flow cytometry features of urine and bladder washings were compared in 81 cases of benign and malignant bladder disease. Some patients were followed by urine cytology and flow cytometry during treatment of tumors. There was a good correlation of the 3 parameters in relatively high grade tumors (II and III) but an inconsistent appearance of cells in the urine diagnosable by either urine cytology or flow cytometry for low grade lesions. High grade flat neoplasms may be detectable by urine cytology and flow cytometry before they are visible on endoscopy. Flow cytometry may indicate urothelial proliferation before it is apparent on urine cytology. Exfoliative benign lesions are diagnosed readily by the combination of urine cytology and flow cytometry. In benign and malignant lesions shedding of viable cells and, therefore, accessibility to urine cytology and flow cytometry are inconsistent. The need for repeated examinations in the case of low grade lesions suggests that the method is not reliable for single test screening programs but it is a valuable means of followup in cases of suspected or diagnosed disease.

Tissue polypeptide antigen (TPA) as a predictor for genitourinary cancers and their metastases

Tissue polypeptide antigen (TPA) is an oncofetal antigen found in human malignant tumors of various origins. We used radioimmunoassay to determine TPA levels in a total of 150 serum samples from 88 patients with different types of genitourinary cancers. The serum TPA level among cancer patients of all stages combined was higher than in normal healthy controls (p less than 0.05). However, when the patients with metastases were excluded from the analysis, the TPA titer was not significantly different from those of the normal controls. The difference in serum TPA between patients with local disease and patients with metastatic lesions was highly significant (p less than 0.0001). The serum TPA levels were significantly decreased in patients who responded to treatment; the levels were significantly increased in those who progressively became worse.

Effects of S-adenosylhomocysteine and analogs on Epstein-Barr virus-induced transformation, expression of the Epstein-Barr virus capsid antigen, and methylation of Epstein-Barr virus DNA

S-Adenosylhomocysteine was found to have no effect on Epstein-Barr virus-induced transformation of B-lymphocytes and to stimulate viral capsid antigen expression only slightly in the FF41-1 cell line. In contrast, the S-adenosylhomocysteine analogs sinefungin and S-isobutyladenosine inhibited Epstein-Barr virus transformation and induced a significant increase in the numbers of cells expressing the viral capsid antigen. An inverse relationship between levels of viral DNA methylation and gene expression was demonstrated.

[Regional distribution of liver cancer and its relation to selenium levels in Qidong County, China]

The selenium (Se) level in barley and maize from 43 communes of Qidong county, a high risk area of liver cancer in China, were assayed. An inverse correlation between the Se level and the liver cancer incidence was observed. An inverse correlation was also observed between the blood Se level and liver cancer incidence of the local residents. When selenite solution was sprayed on the crops during their preflowering, the content of Se in barley and maize was increased by 6 fold over the control. It is suggested that the increase of blood Se level of the residents who live in the low-Se areas by this method be useful in the prevention of liver cancer.

The production of monoclonal antibodies against respiratory syncytial virus and its clinical applications

The availability of monoclonal antibodies against various viral components, either internal nucleoproteins or membrane proteins, has greatly advanced our understanding of the biochemistry of respiratory syncytial virus (RSV). The components responsible for serum neutralization have been identified by monoclonal antibodies, thus facilitating the development of synthetic RSV vaccine. A number of clinical tests have been devised using monoclonal antibodies for either qualitative or quantitative determination of the presence of RSV antigens. The practical procedures for the widely used indirect immunofluorescent antibody (IFA) and enzyme-linked immunosorbent assays (ELISA) are presented. Various commercial ELISA spectrophotometers and washers are also compared and evaluated.

Structure and expression of the human gene encoding major heat shock protein HSP70

We have cloned a human gene encoding the 70,000-dalton heat shock protein (HSP70) from a human genomic library, using the Drosophila HSP70 gene as a heterologous hybridization probe. The human recombinant clone hybridized to a 2.6-kilobase polyadenylated mRNA from HeLa cells exposed to 43 degrees C for 2 h. The 2.6-kilobase mRNA was shown to direct the translation in vitro of a 70,000-dalton protein similar in electrophoretic mobility to the HSP70 synthesized in vivo. From the analysis of S1 nuclease-resistant mRNA-DNA hybrids, the HSP70 gene appears to be transcribed as an uninterrupted mRNA of 2.3 kilobases. We show that the cloned HSP70 gene contains the sequences necessary for heat shock-induced expression by two criteria. First, hamster cells transfected with a subclone containing the HSP70 gene and flanking sequences synthesized a HSP70-like protein upon heat shock. Second, human cells transfected with a chimeric gene containing the 5' flanking sequences of the HSP70 gene and the coding sequences of the bacterial chloramphenicol acetyltransferase gene transcribed the chimeric gene upon heat shock. We show that the HSP70 mRNA transcribed in an adenovirus 5 transformed human cell line (293 cells) is identical to the HSP70 mRNA induced by heat shock.

Megakaryocytopoiesis and granulopoiesis after murine cytomegalovirus infection

Thrombopoiesis and granulopoiesis following murine cytomegalovirus infection were investigated by studying changes in megakaryocytes, megakaryocyte and granulocyte-macrophage progenitor cells, and spleen colony-forming cells. The soft gel in vitro culture system was used to assay for megakaryocyte and granulocyte-macrophage progenitor cells in marrow and spleen. Murine cytomegalovirus produced a mild thrombocytopenia to 90% of control values 1 day after infection at a time when marrow megakaryocyte levels were normal, suggesting a mild direct toxic effect of the virus on platelets. A reduction of megakaryocytes, megakaryocyte and granulocyte-macrophage progenitor cells, and spleen colony-forming cells to 40% to 60% of control values occurred within 24 to 48 hours of infection in association with an additional decrease in platelets to 58% of control levels on day 4. In vitro inoculation of marrow cell cultures with murine cytomegalovirus also resulted in a reduction of megakaryocyte- and granulocyte-macrophage colony-forming cells within 24 to 48 hours, suggesting that murine cytomegalovirus-induced thrombocytopenia and granulocytopenia may be in part caused by direct infection of precursor cells. The recovery of cells in the spleen was followed by a striking seven- to 10-fold increase in spleen colony-forming cells and megakaryocyte and granulocyte-macrophage progenitor cells in the spleen. These marked increases followed significant increases in spleen cell production of colony-stimulating activities within 2 days of murine cytomegalovirus infection, suggesting that hematopoietic cell recovery is mediated by increased local production of colony-stimulating activities in the spleen.

Studies on mechanism of entry of EB virus into non-B lymphocytes. Establishment of an EB virus-producing human-tupaia hybrid cell line TuH18

With the use of the EB virus-producing lymphoblastoid cell line H18, an attempt was made to infect the monolayer cell culture of nasopharyngeal tissue from the normal tupaia, and an EB virus-producing, human-tupaia hybrid cell line was established. The mechanism of entry of EB virus into cells other than B lymphocytes is discussed in this paper.

Serologic diagnosis of nasopharyngeal carcinoma. A double-blind study of four EB virus antibodies with evaluation by sequential discrimination

It is generally known that a close relationship exists between Epstein-Barr Virus (EBV) and nasopharyngeal carcinoma (NPC). Recently, patients with early lesions of NPC have been detected in the general population by use of serologic mass survey. Using the double-blind method, we have studied the diagnostic value of the four EBV antibody titers, VCA-IgA, VCA-IgG, EA-IgA and EA-IgG, in four groups of subjects, each consisting of 50 persons: patients with nasopharyngeal carcinoma (NPC group), patients with cancers other than NPC in the head and neck regions (HNC group), patients with cancers outside of head and neck regions (OC group) and normal individuals (NS group). The results of these four antibodies were evaluated both singularly and together by multivariate sequential discrimination. Taking 1:10 as the criterion of being positive, in the NPC group, the positive rate of VCA-IgA is 88%, the VCA-IgG rate is 100%, the EA-IgA rate is 48% and the EA-IgG rate is 74%. In the non-NPC group, the positive rates of VCA-IgA are as high as 86%-92%, but those of the other antibodies are as low as 0-42%. The positive rates and the geometric mean titers of these four antibodies were all elevated as compared with those in the three non-NPC groups. These differences are statistically significant. VCA-IgG is unimportant in the diagnosis of NPC because of its low specificity. By treating the antibody titers of VCA-IgA, VCA-IgG, EA-IgA and EA-IgG with sequential discrimination, the correlation rate between the serology and pathology of NPC is 88% and the false positive rate is 7.3%.

Inhibition of PM-2 DNA degradation by a human serum protein

A unique DNA-binding protein was detected that inhibited DNA degradation induced by bleomycin and was decreased in sera of cancer patients. The protein from normal human serum was purified to homogeneity by ammonium sulfate precipitation and DEAE-cellulose and DNA-cellulose column chromatography. Two-dimensional isoelectric focusing gel electrophoresis revealed a single protein spot with a molecular weight of 64,000 and a pI at pH 5.9. The NH2 terminus was lysine, and the ratio of acidic to basic residues was 1.2. DNA binding was demonstrated by column chromatography, agarose gel electrophoresis, fluorescence quenching, and circular dichroism. The inhibitory activity was abolished by treatment with Pronase but not by RNase or DNase I. FeCl2 caused a partial loss of inhibitory activity. The inhibition of DNA degradation was more effective for breakage induced by bleomycin than neocarzinostatin, macromomycin, or DNase I. Evidence from DNA-binding studies suggests the inhibition is due to binding of the protein to sites on DNA preferred by bleomycin. Thus, the protein could be useful for studies on the mechanism of action of bleomycin and other antitumor agents, the cytotoxic effects of which are due primarily to damage of cellular DNA. The protein was decreased significantly in sera of cancer patients, and its potential use as a diagnostic tool for neoplasias is being investigated further.