Antibody response to Epstein-Barr-virus-specific DNase in 13 patients with nasopharyngeal carcinoma in Taiwan: a retrospective study

Serum samples obtained from 13 individuals who were found to have a previous history of or to be suffering from nasopharyngeal carcinoma (NPC) were examined for the presence of antibody to Epstein-Barr virus (EBV) DNase activity. Significant to high levels of antibody to EBV DNase activity were detected in most serum samples obtained from four patients prior to the diagnosis of NPC. The samples from the other nine patients showed variable levels of antibody. The majority of the samples collected at the remission stage of the disease, especially those from long-term survivors, contained little or no antibody to the DNase activity. Data presented here suggest that antibody to EBV DNase activity may be a useful marker for the early diagnosis as well as the prognosis of NPC.

Cell membrane polarity in rat ascites hepatoma cells. Distribution of a cell surface-associated adhesive factor on the cell surfaces

As previously described, a cell surface-associated adhesive factor (AF) was separated from differentiated rat ascites hepatoma AH136B cells (forming cell islands in vivo) and highly purified by chromatography. AF induces not only aggregation of dissociated AH136B cells or undifferentiated rat ascites hepatoma AH109A cells (present as free cells in vivo), but also adhesiveness characterized by the development of junctional complexes. The localization of AF on the surfaces of AH136B cell islands was investigated using anti-AF IgG (Fab fragment) coupled to peroxidase. AF was detected in the contact region of the lateral surfaces of the AH136B cells and in the intercellular spaces. In contacted free cell surfaces of AH136B cells. Fluorescence studies revealed that biotin-labeled AF did not bind to the apical surface of AH136B cell islands. These results indicate a distinct difference between apical and lateral surfaces of AH136B cells; neither AF nor binding site for AF were localized on the apical surface of AH136B cells, whereas both were localized on the lateral surface. On the other hand, AH136B cells detached from the cell islands, or during the process of partial dissociation from them, showed the loss of the AF localization and binding site of AF on the surfaces. The results suggest that AH136B cell surfaces may be polarized in terms of the AF localization, and this polarization may be lost after cell dissociation.

Bacterial Alginate Produced by a Mutant of Azotobacter vinelandii

The optimum conditions in shaken flasks for production of bacterial alginate by mutant C-14 of Azotobacter vinelandii NCIB 9068 and a comparison of the properties of bacterial and algal alginates were investigated. The largest amount of bacterial alginate was obtained in about 110 h by a culture grown on optimum medium at 34°C and 170-rpm shaking speed. The viscosity of the culture broth was 18,400 cps and the alginate concentration reached 6.22 g/liter. The viscosity of the purified bacterial alginate was as high as 11,200 cps at a low concentration (0.6%). A greater than fivefold concentration of algal alginate was required to reach the same viscosity at a low shear rate. A solution of bacterial alginate was more pseudoplastic than that of algal alginate was. No significant differences were observed in other properties of bacterial and algal alginates such as gel formation with calcium ion, thermostability, and effect of temperature, pH, and sodium chloride on viscosity.

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.

Prediction and improvement of protected peptide solubility in organic solvents

A predictive method of solubility for protected peptide fragments of globular proteins was described. The solubility prediction was performed on the basis of both the randomness of peptide structures in a solid state and the existence of tertiary peptide bonds such as X-Pro and X-(Z) Y bonds, in which X and Y are arbitrary amino acid residues and Z is a suitable protecting group for the X-Y peptide bond. In order to predict the randomness, the coil conformational parameter, Pc, was utilized. Solubility prediction by this method was successfully applied to the two classes of protected peptides composed solely of hydrophobic and of various amino acid residues. The solubility test results also indicate that the protection of peptide bonds at suitable intervals is effective in achieving a remarkable improvement in the solubility of extraordinarily insoluble peptides. Lastly, the strategy for the selection of the coupling routes in the protein syntheses was proposed.

Anion-exchange chromatography of proteins on AG MP-1 using high-performance liquid chromatography equipment

That the macroporous anion-exchange resin AG MP-1 can be used with HPLC equipment and common aqueous buffers for the chromatography of proteins is shown. The utility of this system is illustrated by the partial purification and complete resolution of the three protein synthesis elongation factors from each other, starting with a crude extract of Escherichia coli. The factors were purified 10- to 30-fold in a yield of 50 to 90% with a single 60-min chromatographic program of increasing NaCl concentration. Other proteins from various biological sources were purified with similar results. Thus, it appears that AG MP-1 is useful, at least in some applications, for the rapid, reproducible, and economical purification of proteins using HPLC equipment.

Antibody to Epstein-Barr virus specific DNase in sera of nasopharyngeal carcinoma and other nine most common cancer patients in Taiwan

Sera from 119 patients with nasopharyngeal carcinoma (NPC), 33 patients with other cancers of the head and neck, 220 normal subjects and various numbers of patients with each of the other nine most common cancers in Taiwan were examined for their serum antibody response to Epstein-Barr virus (EBV)-specific DNase. The positive rate (neutralizing activity greater than 2 units) in normal subjects was 5.5%; 12.1% in patients with other cancers of the head and neck, 87.4% in NPC patients and 0% (colon or rectal cancer) to 30% (lung cancer) in the other nine cancer patients. There is statistically significant difference of positive rates between NPC patients and lung cancer patients (p less than 0.001). Briefly, the test has 87% sensitivity and 95% specificity for NPC patients. Therefore titration of the serum antibody reactivity to EBV-specific DNase can be used as a method for massive screening for the early diagnosis of NPC.

Activity of DNase associated with replication of Epstein-Barr virus in NPC-204 cells

A deoxyribonuclease derived from Epstein-Barr virus (EBV)-producing lymphoblastoid cell line (NPC-204 cells) treated with IUdR was purified by DEAE cellulose, phospho-cellulose, and DNA-cellulose columns with 45% recovery. The activity of the DNase was neutralized by serum of patient with nasopharyngeal carcinoma (NPC). The DNase had a strong requirement for divalent cations and an alkaline pH optimum. Its activity was inhibited by highly ionic strength and polyamines.

A histological study of the promotive effect of diethylstilbestrol on diethylnitrosamine initiated carcinogenesis of liver in rat

A single dose (80 mg/kg) of diethylnitrosamine (DEN) was given orally to castrated female Wistar rats. One week after that one half of the animals were treated with diethylstilbestrol (DES) 3 mg/kg/once a week subcutaneously. The other half of the animals received no any hormone or hormone derivatives. The change of the liver cells in animals treated with DEN alone failed to progress beyond the stage of hepatocellular alterations in foci or neoplastic nodules within 8 months, while most of those animals which received DES treatment after DEN initiation developed hepatocellular carcinomas after 6 months. This result denotes that the DES exerts a definite promotive effect on DEN initiated liver cell carcinogenesis.

Antibody to Epstein-Barr virus-specific DNase in patients with nasopharyngeal carcinoma

Sera from 99 patients with nasopharyngeal carcinoma (NPC), 17 patients with diseases other than NPC and 24 healthy individuals were examined for their antibody activities to Epstein-Barr virus (EBV) DNase. Most of the sera from NPC patients showed high level of antibody activity even in the stage I of the disease. On the contrary, sera from healthy donors and patients with diseases other than NPC showed only very little or none of the activity. The results strongly suggest that the test for EBV DNase activity could be used for the early diagnosis of NPC.

Detection of deoxyribonuclease activities of Mycoplasma pneumoniae

Alkaline deoxyribonuclease activity was detected in culture of Mycoplasma pneumoniae. This enzyme required MgCl2 to stimulate its activity and preferred double-stranded to single-stranded DNA as substrate. By using polyacrylamide gel electrophoresis or isoelectric electrofocusing, two distinctive deoxyribonuclease activities were demonstrated both in cultured broth and cell homogenate.

Mode of action of phosphonoformate as an anti-herpes simplex virus agent

Phosphonoformate inhibited the replication of Herpes simplex virus (HSV) type 1 and type 2 in culture. The concentration required to inhibit the replication of both types of virus by 2 logs at 28 h post-infection was approximately 150 microM. It was more potent than phosphonoacetate against the growth of both virus types. A virus mutant which is resistant to phosphonoacetate was cross-resistant to phosphonoformate. Arsonoacetate, at 300 microM, had no antivirus activity. Phosphonoformate also inhibited HeLa and KB cell growth; at a concentration of about 500 microM, cell growth was inhibited by 50%. The anti-cell growth effects of the drug were completely reversible. The antivirus effect of phosphonoformate was partially reversible, depending on the time and duration of exposure of infected cultures to the drug. To obtain the maximum antivirus effect, phosphonoformate had to be added within the first 3 h post-virus-infection and be continuously present for at least 18 h. Phosphonoformate, added at 0 h post-infection, suppressed the induction of virus-specific DNA polymerase and DNAase activities. dTMP incorporation into DNA was preferentially inhibited in nuclei isolated from infected cells compared to uninfected cells, and the degree of inhibition varied with the ionic strength of the assay. Phosphonoformate was a potent inhibitor of the purified HSV-1 and HSV-2 DNA polymerases, inhibiting DNA polymerase activity by 50% at a concentration of 3 microM and ionic strength of 0.2.

Frequency and levels of antibodies to Epstein-Barr virus-specific DNase are elevated in patients with nasopharyngeal carcinoma

Sera from healthy individuals and patients with infectious mononucleosis, Burkitt lymphoma, nasopharyngeal carcinoma, or other malignancies were examined for their capacity to neutralize Epstein-Barr virus (EBV)-induced DNase activity. Sera were found that neutralized the EBV DNase but not herpes simplex virus type 1 or type 2 DNases, and vice versa. Sera from 46 of the 49 patients with nasopharyngeal carcinoma examined (94%) neutralized > 6 units of EBV DNase per ml of serum. In contrast, only 19% of 47 patients with Burkitt lymphoma, 12% of 183 patient with other malignancies, 4% of 58 patients with infectious mononucleosis, and none of 101 healthy individuals had such levels of neutralizing activity. The neutralizing factor was found in the IgG fraction derived from nasopharyngeal carcinoma sera. There was no correlation between the concentration of these antibodie and the titers of IgG ad IgA antibodies to the EBV capsid antigen, the early antigen complex, or the EBV-associated nuclear antigen.

Methemoglobin reduction in red cells: effect of a high oxygen affinity hemoglobin

Erythrocytes from heterozygous carriers of the high oxygen affinity mutant hemoglobin, Hb Wood, demonstrate lower rates of methemoglobin reduction than normal human red cells when incubated in the in vitro system of Beutler and Baluda. The rate of methemoglobin reduction in red cells from an individual who is heterozygous for both NADH-methoglobin reductase deficiency and Hb Wood shows the combined effects of the two mutations.