Identification of two factors required for transcription of the ovalbumin gene

Two transcription factors, COUP and S300-II, were isolated and partially purified from HeLa cell nuclear extracts. Both factors are required for the efficient transcription in vitro of the ovalbumin gene but not the simian virus 40 early genes. COUP factor binds to the chicken ovalbumin upstream promoter (COUP) sequence which lies between -70 to -90 base pairs upstream from the cap site. A series of competition experiments with a band-shifting assay was carried out to determine the relative affinity of COUP box transcription factor for various promoters. We found that a promoter DNA fragment isolated from the ovalbumin gene competes better than those isolated from the ovomucoid, Y, and alpha-genes. In contrast, the the simian virus 40 early genes, the beta-globin gene, and the adenosine deaminase gene promoters do not compete well in this assay. The molecular weight of the COUP factor was estimated by S-300 column chromatography, glycerol gradient centrifugation to be 90,000. However, two bands were observed in sodium dodecyl sulfate gel electrophoresis of cross-linked COUP factor to a 32P-labeled oligonucleotide containing the COUP sequence. The protein moieties of the major and minor bands were estimated to be 85,000 to 90,000 and 40,000 to 45,000, respectively. The S300-II factor with an apparent molecular weight of 45,000 in an S-300 column is required for function in an in vitro reconstituted transcription system. In contrast to the COUP factor, the S300-II factor does not have apparent specificity for binding to the ovalbumin gene promoter. The S300-II factor may function by interacting with RNA polymerase or other DNA-binding transcription factors.

Video time-lapse microscopy of human laryngeal carcinomas in vitro

Twelve human laryngeal carcinomas and 14 normal vocal cord epithelia were studied in vitro by the method of tissue culture incorporating video time-lapse microscopy. Different events were photographed by taking 'stills' from the television monitor during play-back. Outgrowths from both tumour and normal explants formed only as monolayers. Mitoses were mainly found to be localized approximately mid-way between explant and the edge of the outgrowth. Some cells were seen to become suddenly active producing oscillating blebs and sometimes they detached themselves from the monolayer culture and changed appearance. This was more prevalent in the tumour cultures. In both tumour and normal cell cultures lymphocytes were observed and their normal chemokinetic movement was changed into a rapid chemotactic attraction by the presence of a mitotic epithelial cell. These lymphocytes appear to represent T-suppressor cells. The present study has shown that primary tissue culture can be a valuable tool in the study of laryngeal carcinoma. The interaction between mitotic tumour cells and lymphocytes may represent a transformation of T-lymphocytes into LAK cells.

2-Cyanocinnamic acid sensitization of L929 cells to killing by hyperthermia

Exposure of L929 cells to hyperthermia in the presence of 2-cyanocinnamic acid, an inhibitor of mitochondrial pyruvate transport, markedly enhanced killing at temperatures as low as 41 degrees C. The inhibitor also reduced the oxidation of both glucose and exogenous pyruvate while increasing lactate production from glucose but not from pyruvate. These results are consistent with previous observations that glucose and pyruvate enhance survival after hyperthermia and point to a role for pyruvate in protecting against hyperthermic cytotoxicity. Heat shock protein synthesis was also inhibited by 2-cyanocinnamic acid under some conditions, suggesting that a function of pyruvate may also be involved in heat shock protein induction.

Spectroelectrochemical study of cytochrome c oxidase: pH and temperature dependences of the cytochrome potentials. Characterization of site-site interactions

The cytochrome a and a3 sites in uninhibited, detergent-solubilized cytochrome c oxidase have been studied under a wide range of conditions using thin-layer spectroelectrochemistry. The observed absorbance changes at the alpha and Soret absorbance maxima have been used together to estimate the extents of reduction of cytochromes a and a3, using the absorbance properties of these cytochromes deduced from previous measurements employing ligand inhibition of cytochrome a3. The resulting Nernst plots, combined with the results of parallel studies on the carbon monoxide-inhibited enzyme (Ellis, W. R., Jr., Wang, H., Blair, D. F., Gray, H. B., and Chan, S. I. (1986) Biochemistry 25, 161-167; Wang, H., Blair, D. F., Ellis, W. R., Jr., Gray, H. B., and Chan, S. I. (1986) Biochemistry 25, 167-171), indicate that the cytochrome a site participates in anticooperative thermodynamic interactions which involve all three of the other metal sites in the protein. Using an analysis which resolves the intrinsic thermodynamic properties of the cytochromes from the effects of the intersite interactions, the pH, temperature, and ionic strength dependences of the cytochrome reduction potentials have been measured. The standard entropy of reduction of cytochrome a in the native enzyme is large and negative, in agreement with measurements on the carbon monoxide-inhibited enzyme. The reduction potential of cytochrome a is only moderately (less than -30 mV/pH unit) dependent upon pH, which implies that its reduction is linked to the uptake, on the average, of only about 0.5 protons at pH 7.0, and significantly less at the higher pH values relevant to the mitochondrial matrix. The thermodynamic properties of cytochrome a3 were found to be different in the two enzyme batches studied: in one batch, the cytochrome a3 reduction potential decreased steeply (about -56 mV/pH unit) with increasing pH, indicating stoichiometric (1 H+/e-) coupling of protonation to reduction. In the other batch, the cytochrome a3 potential was insensitive to pH below pH 7.5 and decreased at higher pH values in a manner suggesting coupling to an ionizable group with pKa near 7.8. The temperature dependence of the cytochrome a3 reduction potential indicates that its standard entropy of reduction is more positive than that of myoglobin, another high-spin metalloprotein heme, and significantly more positive than that of cytochrome a.(ABSTRACT TRUNCATED AT 400 WORDS)

Control of transcription initiation in vitro requires binding of a transcription factor to the distal promoter of the ovalbumin gene

We used a cell-free HeLa cell transcription system to identify and characterize transcription factors and the promoter elements that they recognize in RNA polymerase II-transcribed genes. Deletion of the region (-71 to -83) containing the GTCAAA direct repeat resulted in a marked decrease of specific transcription of the ovalbumin gene; transcription could be competed with DNA fragments containing this sequence. Furthermore, DNase I footprinting identified a protein-binding site including this direct repeat with crude extracts and one of the partially purified protein fractions required for transcription. We propose that a soluble factor activates transcription through binding to the direct repeat of GTCAAA sequence upstream from the ovalbumin gene.

Resistance to adriamycin: relationship of cytotoxicity to drug uptake and DNA single- and double-strand breakage in cloned cell lines of adriamycin-sensitive and -resistant P388 leukemia

Cloned lines of Adriamycin (ADR)-sensitive and -resistant P388 leukemia have been established from single cell cultures. A marker chromosome M1 was found in all cells in the heterogeneous resistant P388/ADR parental line as well as in the cloned resistant lines P388/ADR/3 and P388/ADR/7; a different marker chromosome M2 was present in the heterogeneous sensitive P388 parental line as well as the cloned sensitive line P388/4. Dose-survival studies showed that D0, the dose of Adriamycin reducing survival to 1/e (i.e., 37% of the initial population), was 33 +/- 5 (SE) nM for sensitive P388/4 cells, 169 +/- 17 nM for resistant P388/ADR/3 cells, and 336 +/- 28 nM for the more resistant P388/ADR/7 cells. Drug uptake in sensitive P388/4 cells was 1.6-fold greater than in resistant P388/ADR/3 cells and 2.1-fold greater than in resistant P388/ADR/7 cells. The number of DNA single-strand breaks produced per microM Adriamycin was 131 +/- 9 rad equivalents in sensitive clone 4 cells, 41 +/- 8 rad equivalents in resistant clone 3 cells, and 33 +/- 11 rad equivalents in resistant clone 7 cells. The number of DNA double-strand breaks per microM Adriamycin was 1721 +/- 126 rad equivalents in sensitive cells, 117 +/- 36 rad equivalents in resistant P388/ADR/3 cells, and 194 +/- 16 rad equivalents in resistant P388/ADR/7 cells. Differences in drug uptake were insufficient to explain the higher incidence of DNA single- and double-strand breaks in sensitive cells. These findings strongly support the concept that resistance to Adriamycin in P388 leukemia cells is multifactorial; however, this study did not resolve whether these changes arise from a single pleiotropic mutation or from multiple mutations. In sensitive P388/4 cells the number of DNA single-strand breaks formed could all be attributed to double-strand breaks. However, in both resistant cell lines the level of induction of single-strand breaks was in excess of that due to double-strand breaks, and this excess of single-strand breaks appeared to vary directly with the degree of resistance, being greater in the more resistant clone 7 cells than in the less resistant clone 3 cells. In both sensitive and resistant cell lines the ratio of true single- to double-strand breaks varied inversely with the concentration of Adriamycin. Finally, the cytotoxic activity of Adriamycin appeared to correlate more closely with formation of DNA double-strand breaks than with single-strand lesions.

Morphologic changes in primary neuroendocrine carcinoma of the skin following radiation therapy

A case of primary neuroendocrine carcinoma of the skin (NECS) treated by radiation therapy is reported. Biopsy prior to irradiation showed a tumor with the characteristic light microscopic, immunohistochemical, and ultrastructural features of NECS. Following external beam irradiation, 6,000 rad, the size of the lesion decreased markedly. Examination of the excised residual mass revealed dense fibrous connective tissue with entrapped nests of large tumor cells that differed markedly from those in the previous biopsy specimen. The neoplastic cells in the excised mass had abundant, vacuolated, eosinophilic cytoplasm and pleomorphic nuclei. In spite of these marked morphologic alterations, the original immunohistochemical phenotype was retained. These observations suggest that radiation may induce profound histologic changes in NECS.

Spectroelectrochemical study of the cytochrome a site in carbon monoxide inhibited cytochrome c oxidase

The reduction potential of the cytochrome a site in the carbon monoxide derivative of beef heart cytochrome c oxidase has been studied under a variety of conditions by thin-layer spectroelectrochemistry. The reduction potential exhibits no ionic strength dependence and only a 9 mV/pH unit dependence between pH 6.5 and 8.5. The weak pH dependence indicates that protonation of the protein is not stoichiometrically linked to oxidoreduction over the pH range examined. The temperature dependence of the reduction potential implies a relatively large standard entropy of reduction of cytochrome a. The measured thermodynamic parameters for reduction of cyctochrome a are (all relative to the normal hydrogen electrode) delta Go'(25 degrees C) = -6.37 kcal mol-1, delta Ho' = -21.5 kcal mol-1, and delta So' = -50.8 eu. When cytochrome c is bound to the oxidase, the reduction potential of cytochrome a and its temperature dependence are not measurably affected. Under all conditions studied, the cytochrome a site did not exhibit simple Nernstian n = 1 behavior. The titration behavior of the site is consistent with a moderately strong anticooperative interaction between cytochrome a and CuA [Wang, H., Blair, D. F., Ellis, W. R., Jr., Gray, H. B., & Chan, S. I. (1985) Biochemistry (following paper in this issue)].

Temperature dependence of the reduction potential of CuA in carbon monoxide inhibited cytochrome c oxidase

The temperature dependence of the reduction potential of the CuA site in carbon monoxide inhibited cytochrome c oxidase has been measured with a spectroelectrochemical method adapted to the relatively weak near-infrared absorption of this copper ion. These measurements, together with parallel measurements on the 604-nm absorption due to Fea, indicate that an interaction between CuA and Fea causes the reduction potential for one of these sites to be decreased by approximately 40 mV upon reduction of the other. The temperature dependence of the CuA reduction potential indicates a relatively large and negative standard entropy of reduction of CuA (delta So' = -48.7 +/- 2.3 eu). Possible implications of the intersite redox interaction and the large standard entropy of reduction of the CuA site are discussed.

Computed tomography of dural sinus thrombosis

The four patients presented here demonstrate the value of contrast enhanced CT in the diagnosis and serial evaluation of dural sinus thrombosis. Two patients were young women using oral contraceptives; another patient had lateral sinus thrombosis complicating mastoiditis; a fourth patient developed superior sagittal sinus thrombosis following hip surgery. Improvements in CT diagnosis, including the use of thin sections for evaluation of the deep venous structures and lateral sinuses complemented by multiplanar reconstruction or direct coronal scanning, are discussed. Sequential scans for following the progress of two patients treated by barbiturate coma added to the understanding of dural sinus occlusive disease.

CT myelography for outpatients. An inpatient/outpatient pilot study to assess methodology

The diagnostic usefulness, limitations, and adverse reactions associated with computed tomographic myelography using metrizamide were assessed for broad outpatient application. The initial approach was to examine inpatients (n = 38) with low-dose metrizamide (100 mgI/ml). This low dose was believed less likely to be associated with side effects. They were then treated as if they were outpatients, with the liberties this entailed. The consequences of needle puncture were minimized by using a 25-gauge disposable needle. Thirty-four (89%) patients remained free of side effects after the procedure. Subsequently, this technique was extended to 42 outpatients, 38 (90.5%) of whom remained asymptomatic. For comparison, 170 mgI/ml was used in another 25 outpatients, who evidenced more symptoms. The potential medical, economic, and therapeutic benefits of obviating hospitalization by safer outpatient CT myelography seem clear.

The use of computed tomography of the spine to identify patients at high risk for epidural metastases

The usefulness of spinal computed tomography (CT) in predicting the presence of epidural tumor was evaluated in cancer patients undergoing CT myelography for suspected epidural tumor. Two hundred ninety two vertebral levels were evaluated in 30 patients. Spinal CT demonstrated cortical disruption surrounding the epidural space from metastatic cancer in 109 vertebrae. Eighty-five (78%) of these vertebral levels had tumor extension into the adjacent epidural space. The incidence of epidural tumor adjacent to vertebrae which had normal spinal CT or metastatic tumor without cortical disruption was 11%. Eighty-six percent of the epidural tumor adjacent to these vertebrae were a result of craniocaudal tumor extension in the epidural space from adjacent vertebral levels with cortical disruption. Twenty-one of 23 patients (91%) with cortical disruption at more than one vertebral level on spinal CT had epidural tumor. Synchronous noncontiguous epidural lesions were observed in 38% of patients with epidural tumor. Spinal CT is an important diagnostic test in determining which patients are at high risk for epidural tumor. Myelography should be performed in all patients with suspected epidural tumor to accurately define the full extent of tumor.

A study of dynamic development in radiolesion and cell death of eukaryotes after exposure to ionizing radiation--the visualization of the dynamic reaction by means of cytochemical method with lactate dehydrogenase (LDH) as a nuclear marker and radiation-induced nuclear anomalization by an ultramicrostructural manifestation: a dynamic explanation

The present work deals with the radiation effect on adult rats suffering from acute, whole-body irradiation with cobalt-60 gamma rays of dosages 100R and 300R respectively. The morphological alteration of the lymphocytic nucleus and exhibition of cytochemical reaction of LDH in intra- or extra-nuclear region has been observed at the end of predetermined time intervals after irradiation. A close relationship between the percentage of damage of the lymphocytic nucleus and that of positivity of LDH reaction is seen from their variations with time parallel. From technical color microphotographs which exhibit cytochemical reactions, the existence of enzyme LDH in the nucleus so far obscure has been visually recognized. The events happening in enzymic reaction and the leakage of enzyme across the nuclear envelope reflect the dynamic nature. The ultrastructural alteration of nuclear anomalization confirms the dynamic development of inducing radiolesion. The experimental facts inspire us to attempt an explanation of cellular radiolesion and cell death owing to ionization radiation in light of the dynamic concept.