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.

Allosteric effect of o-iodobenzoate on hemoglobin

O-Iodobenzoate interacts non-covalently with hemoglobin and lowers the oxygen affinity of the protein. In contrast to 2,3-diphosphoglycerate or inositol hexaphosphate, its interaction does not depend upon the presence of free amino groups at the beta-chain amino terminals. Lysine beta82 is one of its oxygenation linked binding sites. As with the organic phosphates, the halogenated benzoate reacts preferentially with deoxy-hemoglobin to shift the allosteric equilibrium from R to T.

Hemoglobin A and B of the cat: occurrence in the same cell

The two major hemoglobins found in domestic cat blood occur within the same erythrocyte. A putative asymmetrical hybrid, alpha2betaAbetaB, is shown to be present in the cell by isoelectric focusing.

Effects of cordacin on lymphocyte activity in vitro

The effects of cordacin on lymphocyte activity were studied with two parameters in vitro. The cordacin inhibited T lymphocyte E rosette formation by 93% at the concentration of 1,000 microgram/ml and tritiated-thymidine incorporation into PHA-transformed lymphocytes by 66% at the concentration of 10 microgram/ml. The implication of these results on replicating leukemic as well as normal cells is discussed.

Studies on Thermoactinomyces sp. TM9208. I. Description of the strain

A strain of Thermoactinomyces sp., TM9208, isolated from a soil sample in the Taipei area showed antagonistic activity to Gram positive bacteria but not to the Gram negative on the potato extract agar plate by the cross streaking method. The strain showed strong starch hydrolysis, beta type of hemolysis, brownish yellow growth on the potato extract agar and green on the nutrient agar. Its aerial mycelium, white to grayish white, was long and straight with short branches. The spores are single and have smooth surface. It is a good utilizer of starch, maltose and cellobiose as carbon source, but utilizes dulcitol, salicin, sucrose, rhamnose and sorbitol poorly.

Identification by physical means of organic moieties of conjugates produced from carbaryl by tobacco cells in suspension culture

Carbaryl (1-naphthyl methylcarbamate), labeled with 14C in the C1-naphthyl, carbonyl, or N-methyl position, was introduced into the culture medium of tobacco cells in suspension culture. Following incubation, cells were homogenized in water, centrifugated, and supernatants hydrolyzed with beta-glucosidase or HCl. Organic moieties (moieties) were characterized by two-dimensional thin-layer chromatography (TLC), and many were subsequently identified by infrared and mass spectrometry. On the basis of the data obtained with 14C1-naphthyl-labeled carbaryl, it appeared that 18.4% of the total characterized metabolites represented unconjugated N-CH2OH- carbaryl [1-naphthyl N-(hydroxymethyl)carbamate], excreted by the cells into the culture medium. The metabolites found in the cells primarily consisted of conjugates of 1-naphthol (73.6% of the total characterized metabolites) and N-CH2OH-carbaryl (2.5%). Conjugates of 7-hydroxycarbaryl (7-hydroxy-1-napthyl methylcarbamate), 4-hydroxycarbaryl (4-hydroxy-1-naphthyl methylcarbamate), and 5-hydroxycarbaryl (5-hydroxy-1-naphthyl methylcarbamate) were also detected in small amounts. Of five unknown 14C1-naphthyl-labeled carbaryl metabolites, three were tentatively characterized as: O-1-naphthylcholesterol (Cholest-5-en-3beta-yl-1-napthol: 3.0%); an unconjugated hydroxylated 1,4-dihydro-1,4-epiperoxynapththalene (1.4%); and an acidlabile, beta-glucosidase-resistant conjugate of a cis-dihydrodiol of 1-naphthol (0.3%; other than the trans-5,6-dihydrodiol). The cholesterol derivative may represent a new "detoxification mechanism" in plants; the epiperoxide may help to elucidate plant oxidation mechanisms. A new TLC procedure was developed which successfully separated the acetate derivative of N-hydroxycarbaryl (1-naphthyl N-hydroxy-N-methylcarbamate) from 12 other common moieties of carbaryl metabolites and their acetate derivatives. A new two-dimensional TLC system was developed for the separation of underivatized N-hydroxycarbaryl from 14 other moieties of carbaryl metabolites; two additional two-dimensional TLC systems were utilized for moiety separations. With these TLC procedures, no conjugated or unconjugated N-hydroxycarbaryl could be detected in any tobacco cell culture fraction after incubation of cells in medium containing radiolabeled carbaryl. Authentic 14C1-naphthyl-labeled N-CH2OH-carbaryl was shown to be converted to desmethylcarbaryl (1-naphthylcarbamate) 97%) and 1-naphthol (3%) by 0.1N HCl hydrolysis.

Fatal primary Epstein-Barr virus infection masquerading as histiocytic medullary reticulosis in young children in Taiwan

We reported 3 fatal cases of primary Epstein-Barr virus (EBV) infection resembling histiocytic medullary reticulosis (HMR) in young children in Taiwan, where an HMR-like illness has been previously found to be prevalent. The disease ran a fulminant course, manifesting as fever, anemia, jaundice, skin rash, pulmonary infiltration, and/or hepatosplenomegaly lasting for only 1-3 weeks. Laboratory tests revealed no hemolytic anemia and Coombs test was negative. Sepsis or HMR was the main clinical differential. At autopsy, the spleen, liver, lymph node, lung, and bone marrow showed infiltration of atypical "histiocytes" or blasts, lymphocytes, and mature histiocytes with hemophagocytosis. Immunophenotype and gene rearrangement studies of the lymphoid tissues revealed that these atypical "histiocytes" were actually polyclonal B immunoblasts in one case and transformed T lymphocytes in the remaining 2 cases, representing two different types of virus-host interaction. Southern blot and in situ hybridization studies on frozen lymphoid tissues demonstrated the presence of EBV DNA in all 3 patients; the study for cytomegalovirus was negative. The young age of these patients, closely correlated with the prevalent age of primary EBV infection in the general populations in Taiwan, strongly suggest that these childhood cases of previously diagnosed HMR-like disease may actually represent a lethal form of primary EBV infection or fatal infectious mononucleosis.