Computerized telephone assessment of the "concrete" needs of chemotherapy outpatients: a feasibility study

The feasibility of using a computer-automated telephone outreach system to routinely assess the needs of chemotherapy outpatients was evaluated. The automated intervention was designed as a cost-efficient strategy for assessing patients' needs on a periodic basis so that emerging needs could be identified in a timely way. Ninety-seven chemotherapy outpatients were surveyed at least once over the telephone by a computer in a high-quality, digitally stored voice asking 12 questions regarding the patients' "concrete" needs. Early results of this larger ongoing study, in which patients are scheduled to be called every 4 to 6 weeks for approximately four months, indicated that computer-automated surveys had broad-based acceptance among our outpatients and that patients were able to comply accurately with the survey's instructions. Furthermore, the speech recognition system was found to be reliable, and patients' response patterns to the automated surveys valid. Nonparticipation in this study (28.0%) was not substantially higher than in our previous research within this patient population and neither nonparticipation nor attrition appeared significantly attributable to the automation itself. This method offers the potential for cost-efficient, universal, and ongoing assessment of patient needs, facilitating timely intervention, and efficient use of professional staff.

Cytochemical localization and biochemical analysis of the enzyme markers in human hepatoma cell lines

Three enzyme makers, glucose-6-phosphatase, ATPase and gamma-glutamyl transpeptidase, have been used in studying carcinogenesis of hepatocellular carcinoma. They have been investigated in animal models and human hepatocellular carcinoma in vivo and in vitro. But the inconsistent levels of these three enzymes associated with this type of carcinoma raised the possibility that the carcinoma cells might have derived from the cells originating from different stages of differentiation. To evaluate this possibility, three human cell lines, Hep G2, Hep 3B, and HA 22T, all thought to be arrested in different stages of differentiation based on their biochemical and morphological characteristics, were used as models. The three enzyme markers glucose-6-phosphatase, ATPase and gamma-glutamyl transpeptidase were examined cytochemically and biochemically. Our results showed that there was no correlation between the ATPase levels and the stages of the cell line's differentiation. But both glucose-6-phosphatase and gamma-glutamyl-transpeptidase were higher in cells that were more differentiated.

Biosynthesis of tRNA in yeast mitochondria. An endonuclease is responsible for the 3'-processing of tRNA precursors

To study the mechanism involved in the 3'-processing of mitochondrial tRNA precursors, we examined tRNA processing in a reconstituted system with a yeast mitochondrial extract. Two mitochondrial tRNA(Glu) precursors synthesized from SP6 RNA polymerase-directed transcription system were used as substrates. One contained a 214-nucleotide 5' terminus and 115-123-nucleotide 3' trailer. The other had the same sized 3' trailer, but contained a mature 5' terminus. An endonucleolytic activity was identified in a mitochondrial S30 fraction which cleaves the 3' terminus of the latter tRNA precursor precisely at the in vivo CCA addition site. No cleavage of the 5'-extended precursor was observed in vitro. This mitochondrial 3'-processing activity was partially purified using DEAE-CL-6B chromatography. It removes the 3' trailer sequence from the 5'-matured precursor leaving a 3'-hydroxyl group on the processed tRNA and a 5'-phosphate group on the trailer. The resulting tRNA product serves as a substrate for tRNA nucleotidyltransferase which catalyzes the addition of CCA residues to the tRNA to complete its 3' maturation. Thus, yeast mitochondrial 3'-tRNA processing events resemble those found in eucaryotic cytoplasmic/nuclear systems where a single endonucleolytic cleavage is responsible for the formation of the 3' end of the tRNAs. This is in contrast to the multistep 3'-processing events known to occur in procaryotes.

Biosynthesis of diphthamide in Saccharomyces cerevisiae. Partial purification and characterization of a specific S-adenosylmethionine:elongation factor 2 methyltransferase

The inactivation of elongation factor 2 (EF-2) by diphtheria toxin requires the presence of a post-translationally modified histidine residue in EF-2. This residue, diphthamide, has the structure 2-[3-carboxyamido-3-(trimethylammonio)propyl]histidine. The present work was undertaken to study the pathway of diphthamide biosynthesis using diphtheria toxin-resistant yeast mutants (Chen. J.-Y., Bodley, J. W., and Livingston, D. M. (1985) Mol. Cell. Biol. 5, 3357-3360) which are defective in diphthamide formation. We demonstrate here that one of these mutants (dph5) contains a toxin-resistant form of EF-2 which can be converted in vitro to a toxin-sensitive form through the action of an enzyme present in other yeast strains. Both this toxin-resistant EF-2 and its modifying enzyme have been partially purified and evidence is presented that the modifying enzyme is a specific S-adenosylmethionine:EF-2 methyltransferase. In vitro complementation to diphtheria toxin sensitivity required S-adenosylmethionine, and when partially purified components were incubated with [methyl-3H]S-adenosylmethionine, label was incorporated specifically into EF-2. Hydrolysis of labeled EF-2 yielded diphthine (the unamidated form of diphthamide) and a single chromatographically separable labeling intermediate. We conclude that the S-adenosylmethionine:EF-2 methyltransferase adds at least the last two of the three methyl groups present in diphthine and that this modification is sufficient to create diphtheria toxin sensitivity. Evidence is also presented for the existence of an ATP-dependent amidating enzyme which catalyzes the final step in the biosynthesis of diphthamide in EF-2.

Detection of hepatitis B virus DNA in hepatocellular carcinoma: methylation of integrated viral DNA

In order to determine whether integrated hepatitis B virus DNA sequences in primary liver tumours are methylated we have analysed tumour DNA digested with either MspI or HpaII restriction endonuclease by Southern hybridization. Our results demonstrate methylation in 11 of 17 tumour DNA samples. Where possible, we have examined the tumour tissues for expression of HBsAg and HBcAg using the indirect immunoperoxidase technique. One tumour was positive for both HBsAg and HBcAg and a second was positive for HBsAg alone. Both of these tumours were in the group in which methylation of integrated HBV DNA sequences could not be detected. We postulate that methylation of integrated HBV DNA sequences may influence HBV gene expression in hepatocellular carcinoma.

Detection of hepatitis B virus DNA in hepatocellular carcinoma: analysis by hybridization with subgenomic DNA fragments

We have previously reported an analysis of DNA extracted from 31 primary liver tumors where, in 25 cases, we found chromosomal integration of hepatitis B virus DNA sequences. We describe here an investigation of the extent of the viral genome at each integration site in 15 of the hepatitis B virus DNA-positive tumors using subgenomic fragments of the viral genome as probes. Probes were roughly equivalent to the pre-S region, the surface antigen gene, the region containing the enhancer, the x gene and the core antigen gene. We found the core antigen gene to be that most underrepresented in the tumors and speculate that, since cells which express core antigen in the infected liver may be targeted for lysis by the immune system, modifications of the integrated viral DNA which prevent core antigen expression may be selected. Conversely, the region of the genome present in the greatest number of integrations was the surface antigen gene and, because it is known that the major surface antigen promoter is active in the integrated state, we find promoter insertion an attractive hypothesis to explain oncogenesis by hepatitis B virus.

Detection of hepatitis B virus DNA in hepatocellular carcinoma: methylation of integrated viral DNA

In order to determine whether integrated hepatitis B virus DNA sequences in primary liver tumours are methylated we have analysed tumour DNA digested with either MspI or HpaII restriction endonuclease by Southern hybridization. Our results demonstrate methylation in 11 of 17 tumour DNA samples. Where possible, we have examined the tumour tissues for expression of HBsAg and HBcAg using the indirect immunoperoxidase technique. One tumour was positive for both HBsAg and HBcAg and a second was positive for HBsAg alone. Both of these tumours were in the group in which methylation of integrated HBV DNA sequences could not be detected. We postulate that methylation of integrated HBV DNA sequences may influence HBV gene expression in hepatocellular carcinoma.

Antibodies to Epstein-Barr virus-specific DNase in patients with nasopharyngeal carcinoma and control groups

Serum samples from 154 patients with nasopharyngeal carcinoma (NPC), 374 with other cancers, 1,000 normal controls from Government Employees' Clinic Center (GECC), and 3,642 individuals of various ethnic-dialect groups living in high-risk areas for NPC were collected and the concentration of antibodies to Epstein-Barr virus (EBV)-specific DNase activity was determined. Taking a serum sample where 1 ml will neutralize two or more units of the DNase activity as positive, 2-4 units as low level, 4-6 units as medium level, and more than 6 units as a high level of antibody, 90.3% of the NPC patients contained significant amounts of antibodies to EBV-specific DNase activity and most of those had high levels of the antibody. In contrast, only 11% of sera from patients with cancers other than NPC contained antibodies to EBV-specific DNase activity, and high levels were very rare (2.1%). The difference in positive rates between these two groups is highly significant according to the chi 2 test (P less than 0.001). The positive rate of this antibody in the control group (GECC) was 5.3% with 0.0%, 0.8%, and 4.5% having high, medium, and low levels of antibodies, respectively. Again, the difference in positive rates between the GECC group and the NPC group is statistically significant (P less than 0.001). Taken separately, the positive rates of anti-EBV DNase activity in the three high-risk groups were 11.7%, 13.0%, and 13.1%. No significant difference in age distribution for the levels of this antibody was observed in the control GECC group or the three high-risk groups. However, the positive rates of the three high-risk groups are more than twice those of the GECC group (11.7% approximately 13.1% vs 5.3%). This ratio coincides with the ratio of the probability of developing NPC in high-risk groups compared to that of the GECC group (also more than two times). The significance of this coincidence is discussed.

Identification of cis- and trans-1,1,2,3,4-pentachloro-4-[1-methylethoxy]-1,3-butadiene residues in Mississippi River fish

The cis- and trans-isomers of 1,1,2,3,4-pentachloro-4-[1-methylethoxy]-1,3-butadiene have been identified as contaminants in fish caught from the Mississippi River at St. Louis, MO, and as far as 150 miles south of that location. Up to 0.1 ppm of the cis-isomer and 0.8 ppm of the trans-isomer were determined by using a method based on the AOAC multiresidue method for detecting organochlorine and organophosphorus pesticides. In tests of the modified AOAC method on spiked fish, both isomers were quantitatively recovered (95-106%). A mixture of the cis- and trans-isomers was synthesized by reacting hexachlorobutadiene with sodium isopropoxide. Separation of the reaction products by Florisil column chromatography provided reference standards of the individual isomers for identification and quantitation of the residues. The stereospecificity of the synthesis reaction and the infrared and mass spectral data used to verify the structures of the products are discussed.

An adhesive glycoprotein from rat ascites hepatoma cells potentiates natural cytotoxic activity by rat spleen cells

In a previous paper, we have described a cell-surface associated adhesive glycoprotein (AF) that has been separated and highly purified from rat ascites hepatoma AH136B cells. AF was found to induce the aggregation and adhesiveness of hepatoma cells. AF was also shown to have a mitogenic activity on rat T lymphocytes, and to stimulate them to produce a lymphokine chemotactic for macrophages. In the present paper, we have examined the effects of AF on natural killing (NK) activity by rat spleen cells against NK-sensitive YAC-1 cells using 51Cr-release cytotoxicity assay. NK activity of spleen cells was potentiated by AF treatment in a dose-dependent manner. A short incubation with AF was sufficient for the potentiation of NK activity, whereas the potentiation by OK-432, which is well known as a potentiator of anti-tumour activity, required a longer stimulation. Macrophage depletion from spleen cells resulted in the decreased potentiating effects of OK-432, whereas the depletion failed to influence the effects of AF. IN subsequent experiments, it was found that AF could potentiate NK activity of the NK-cell enriched fraction. We further found that culture supernatants from spleen cells and peritoneal exudate cells treated with OK-432 potentiate the NK activity, whereas those from AF-treated cells fail. It was thus suggested that AF acts directly on the cells responsible for NK activity, and that the mechanisms of AF-induced potentiation of NK activity differ from those of OK-432-induced potentiation.

Detection of hepatitis B virus DNA in hepatocellular carcinoma

DNA-DNA hybridization was used to examine tissue from 31 patients with hepatocellular carcinoma (HCC) in Taiwan for the presence of the hepatitis B virus genome. Twenty-four of the DNA samples had discrete high molecular weight bands when cut with HindIII and hybridized with a radiolabelled HBV DNA probe, and similar results were obtained with 25 of the samples when cut with EcoRI. Thus integrated HBV DNA was present in almost 80% of the specimens. None of the samples had a similar pattern and most contained HBV DNA integrated at multiple sites. Seventeen out of 19 HBsAg carriers and one out of two patients with anti-HBs were found to have integrated HBV DNA in the tumour tissue, providing further evidence of the strong association between HBV infection and development of hepatocellular carcinoma.