[Comparison between the succinate dehydrogenase inhibition test and ATP assay for in vitro chemosensitivity testing]

The predicted level of cell viability was compared between the succinate dehydrogenase inhibition (SDI) test and the adenosine triphosphate (ATP) assay, both of which are used for in vitro human tumor chemosensitivity testing. After HeLa cells had been exposed to various concentrations of 5-FU for 1, 2, 3 or 4 days, the decrease occurring in viable cell number correlated with that of succinate dehydrogenase (EC 1.3.99.1) activity and that of the intracellular ATP level of the viable cells. In dead cells, the ATP level was extensively decreased, but the succinate dehydrogenase activity remained at a level of 11% of that of 5-FU-untreated viable cells, even on day 4. The cell viability correlated well with the intracellular ATP level, as compared with the succinate dehydrogenase activity. The activity remaining in dead cells must thus be taken into consideration for the prediction of chemosensitivity in the SDI test, but not in the ATP assay.

Medullasin enhances human natural killer cell activity by a mechanism other than the induction of interferons or interleukin-2

The mechanism of activation of human natural killer cell activity by medullasin was studied with special reference to interferons and interleukin-2. Supernatant of lymphocytes treated with medullasin failed to stimulate natural killer cell activity when added to the lymphocyte suspension. Medullasin has been shown to enhance the natural cytotoxicity of lymphocytes stimulated with interferon-alpha or -beta. In the present study, medullasin increased the natural killer cell activity of lymphocytes stimulated with interferon-gamma. Treatment of lymphocytes with medullasin in the presence of antibodies to interferons (alpha, beta and gamma) did not alter the effect of medullasin. Medullasin also increased the natural cytotoxicity of lymphocytes stimulated with interleukin-2. The antibody to interleukin-2 failed to affect the increase of natural killer cell activity by medullasin. These results indicate that the mechanism of activation of human natural killer cell activity by medullasin is not mediated by the induction of interferons or interleukin-2.

[In vitro chemosensitivity of various human tumors evaluated by the succinate dehydrogenase inhibition (SDI) test (2)]

In vitro chemosensitivity was evaluated by succinate dehydrogenase inhibition (SDI) test in 94 human tumors including 59 gastric cancers, 27 colo-rectal cancers and 8 malignant lymphomas. Tumor fragments were exposed to 12 kinds of antitumor drugs at ten times peak plasma concentration. Evaluable rates were 86/94 (91%) for all cases, 56/59 (95%) for gastric cancers, 22/27 (81%) for colo-rectal cancers and 8/8 (100%) for malignant lymphomas. The mean of SD activity was decreased to 48% of that of control cells with aclacinomycin, 49% with carboquone, 53% with actinomycin D, 54% with mitomycin C and 54% with daunomycin for gastric cancers, 59% with adriamycin for colo-rectal cancers and 33% with cyclophosphamide (40487 S), and 33% with actinomycin D, 37% with vinblastine and 39% with adriamycin for malignant lymphomas. When the SD activity was reduced to below 50% by antitumor drugs, the chemosensitivity was defined as positive. The antitumor drugs which had a higher chemosensitive-positive rate were aclacinomycin, carboquone and mitomycin C for gastric cancers, adriamycin for colo-rectal cancers and 40487 S, daunomycin and vinblastine for malignant lymphomas. Our results suggest that the origin of a tumor is a critical factor in its chemosensitivity.

Hutchinson-Gilford progeria syndrome in a 45-year-old man

A 45-year-old man with typical Hutchinson-Gilford progeria syndrome is described. The patient had the characteristic physical findings of this syndrome, such as short stature, "horse-riding" stance, coxa valga, alopecia, micrognathia, craniofacial disproportion, and prominent eyes. He had refractory congestive heart failure due to arteriosclerotic heart disease and hypertension, and he also had arteriosclerosis obliterans. Some immunologic and endocrinologic abnormalities commonly seen in the elderly were present in this patient. On the basis of a review of the literature, this is the first patient with this syndrome who had survived into the fourth decade.

[In vitro chemosensitivity testing evaluated by intracellular ATP level: ATP assay]

In vitro chemosensitivity was evaluated by bioluminescence ATP assay in 12 human tumors including 7 gastric cancers and 5 colo-rectal cancers. Tumor fragments minced with scissors were exposed to 6 kinds of antitumor drugs: carboquone, adriamycin, aclacinomycin A, mitomycin C, cisplatin and 5-FU at peak plasma concentration or ten times peak plasma concentration. After 3 days at 37 degrees C, each tumor fragment suspension was washed with phosphate-buffered saline, boiled for 3 min and assayed for its intracellular ATP level using the luciferin-luciferase method. The ATP level of the drug-untreated group was 6.01 +/- 4.55 X 10(-10) moles/mg tissue protein in gastric cancers and 9.77 +/- 8.46 X 10(-10) moles/mg tissue protein in colo-rectal cancers. The percentages of cases in which the ATP level was reduced to less than 50% by the antitumor drugs were 70% for carboquone, 11% for adriamycin, 30% for aclacinomycin A, 45% for mitomycin C, 13% for cisplatin and 18% for 5-FU at peak plasma concentration, and 90% for carboquone, 78% for adriamycin, 80% for aclacinomycin A, 82% for mitomycin C, 63% for cisplatin and 82% for 5-FU at ten times peak plasma concentration. The test for chemosensitivity prediction is thus available at peak plasma concentration of antitumor drugs in ATP assay.

Cell fusion studies in the Werner syndrome

The mechanism of retarded DNA synthesis was investigated by the cell fusion method. The [3H] TdR labeling index of young cells from patients with Werner syndrome (WS cells) X young normal human diploid fibroblast cells (NH cells) was considerably lower than that of NH homodikaryons, but was significantly higher than that of WS homodikaryons. The labeling index of old WS X young NH heterodikaryons was as low as that of WS homodikaryons. The labeling index of WS X HeLa heterodikaryons was the same as that of HeLa homodikaryons. These results indicate that WS cells are somewhat similar to senescent NH cells. The labeling indices in both WS karyoplast X NH heterodikaryons and WS cytoplast X NH cybrids were lower than those in normal karyoplast X NH heterodikaryons and normal cytoplast X NH cybrids, respectively. These results indicate that both nuclear and cytoplasmic environments are involved in the retarded DNA synthesis in WS cells. The most plausible interpretation of all our data is that the retarded DNA synthesis in WS cells could be caused by either the 'senescent factor(s)' or the deficiency of gene product(s) that is necessary for DNA synthesis and could be a secondary consequence of the genetic defect.

Introduction of human gamma 1 immunoglobulin genes into fertilized mouse eggs

A rearranged human gamma 1 immunoglobulin gene was introduced into fertilized mouse eggs. The phage Ch4A-VCE-gamma 1 was constructed by ligating an EcoRI and BglII fragment of pBR322-CESSV(CE-1) containing the VDJ region with an EcoRI and BamHI fragment of Ch4A-HIg gamma 1-10 containing the gamma 1 constant region. About 200 copies of Ch4A-VCE-gamma 1 genes were introduced into fertilized mouse eggs. Of 489 eggs injected with these genes, 319 survived and were transferred to oviducts of foster mothers. Thirtyeight mice were born and were screened for the presence of human gamma 1 immunoglobulin genes by Southern blot hybridization. Five of these 38 mice had integrated human gamma 1 immunoglobulin genes. None of the human gamma 1 copies in each mouse had undergone deletions or rearrangements as judged by the Southern blotting patterns for several restriction enzymes. Human gamma 1 gene was present in several different tissues. All the mice tested so far transmit the human gamma 1 gene to a fraction of their offspring in an autosomal dominant manner. Spleen cells from transgenic mice were analyzed for immunoglobulin production by reverse plaque assay or immunofluorescence staining of cytoplasmic immunoglobulin, but synthesis and secretion of human gamma 1 chains could not be detected. No human gamma 1 immunoglobulin mRNA was detected in the liver and spleen of a transgenic mouse. The presence of the human gamma 1 immunoglobulin gene appeared to have no effect on the expression of endogenous mouse immunoglobulin genes.

Structure of Marek's disease virus DNA: detailed restriction enzyme map

Purified virion DNA (120 X 10(6) molecular weight [MW]) of Marek's disease virus strain GA was cleaved with BamHI restriction endonuclease, and 27 out of the 29 fragments were cloned into bacterial plasmids. Restriction maps for BamHI, BglI, and SmaI endonucleases were constructed. The genomic structure of Marek's disease virus DNA was found to be similar to that of herpes simplex virus types 1 and 2. A long unique region (75 X 10(6) MW, located at 10 X 10(6) to 85 X 10(6) MW [10-85] from the left end of the genome), which was subdivided into segment 1 (22 X 10(6) MW, located at 10-32) and segment 2 (51 X 10(6) MW, located at 34-85) by direct repeats (32-34), was flanked by a long terminal region (10 X 10(6) MW, located at 0-10) and a long inverted region (10 X 10(6) MW, located at 85-95). A short unique region (8 X 10(6) MW, located at 103-111) was flanked by a short terminal region (8 X 10(6) MW, located at 111-119) and a short inverted region (8 X 10(6) MW, located at 95-103). The direct repeat fragments (0.9 X 10(6) could be isolated by cleavage with SmaI. The right terminal end was found to be heterogenous .

Distribution of gastrin in canine, cat, and human digestive organs

In dogs, cats, and humans, gastrin-containing cells were found only in the antrum and in the duodenum by specific direct immunofluorescence. Distribution within the human duodenum, however, differed from that in cats and dogs. No gastrin-containing cells were seen in other sites of the body.