Metabolic oxidative stress activates signal transduction and gene expression during glucose deprivation in human tumor cells

The mechanism of glucose deprivation-induced activation of Lyn kinase (Lyn), c-Jun N-terminal kinase 1 (JNK1) and increased expression of basic fibroblast growth factor (bFGF) and c-Myc was investigated in MCF-7/ADR adriamycin-resistant human breast carcinoma cells. Glucose deprivation significantly increased steady state levels of oxidized glutathione content (GSSG) and intracellular prooxidants (presumably hydroperoxides) as well as caused the activation of Lyn, JNK1, and the accumulation of bFGF and c-Myc mRNA. The suppression of GSSG accumulation and prooxidant production by treatment with the thiol antioxidant, N-acetylcysteine, also suppressed all the increases in kinase activation and gene expression observed during glucose deprivation. In addition, glucose deprivation was shown to induce oxidative stress in IMR90 SV40 transformed human fibroblasts, indicating that this phenomena is not limited to the MCF-7/ADR cell line. These and previous observations from our laboratory show that glucose deprivation-induced oxidative stress in MCF-7/ADR cells activates signal transduction involving Lyn, JNK1, and mitogen activated protein kinases (ERK1/ERK2) which results in increased bFGF and c-Myc mRNA accumulation. These results provide support for the hypothesis that alterations in intracellular oxidation/reduction reactions link changes in glycolytic metabolism to signal transduction and gene expression in these human tumor cells.     

Improved digital image processing technique to investigate plastic zone formation in steel

An improved digital image processing procedure is developed to extract the size and shape of the plastic zone formation at the tip of a notched metal specimen based on the characteristics of the variation of intensity in a digitized image. The result is compared with the result from finite element analysis, and with that from a previously developed image processing procedure. Comparison shows that this method provides a faster and more accurate result than previously.     

Parasellar epidural hydatid cysts

We report two rare cases of parasellar epidural hydatid cysts. Among the 64 patients with intracranial hydatid cysts we have treated in the past 20 years, only these two cases were located epidurally. Because the location and the computed tomographic characteristics were so different from the other cysts, the preoperative diagnosis was difficult to make. We were unable to remove the cysts without rupturing them because they were tightly surrounded. Both patients underwent surgery twice because of a recurrence. The treatment of this kind of case requires further discussion.     

Comparative genomic hybridization analysis of lobular carcinoma in situ and atypical lobular hyperplasia and potential roles for gains and losses of genetic material in breast neoplasia

Lobular carcinoma in situ (LCIS) and atypical lobular hyperplasia (ALH) of the breast are cytologically similar breast lesions that reportedly carry different relative risks of subsequent development of invasive carcinoma. They are frequently multifocal and bilateral. We have identified the chromosomal copy number changes in 31 LCIS and 14 ALH lesions from 28 cases and also the 7 invasive carcinomas that subsequently developed in 6 of these cases. This was achieved by comparative genomic hybridization analysis of microdissected formalin-fixed, paraffin-embedded material. There was no significant difference between the aberrations found in the unilateral versus the bilateral cases of LCIS. Loss of material from 16p, 16q, 17p, and 22q and also gain of material from 6q were found at a similar high frequency in LCIS and ALH. Loss of these genomic regions may indicate the locations of genes that predispose to the development of the lesions, and the results are consistent with LCIS and ALH representing the same genetic stage of development. Comparison of the comparative genomic hybridization results from LCIS/ALH with those from ductal carcinoma in situ and invasive cancer showed some similarities at the chromosomal level, but it also showed significant differences, including gain of 1q and 8q and evidence for genomic amplification, which were not found in LCIS/ALH. A genetic model is postulated for the possible relationships between noninvasive lobular lesions and invasive breast carcinoma, delineating potential roles for specific chromosome copy number changes.     

In utero cardiac gene transfer via intraplacental delivery of recombinant adenovirus

BACKGROUND: The relationship among the maternal, placental, and uniquely shunted embryonic circulation was explored to provide access to the embryonic cardiovascular system in utero. Manipulation of gene expression in the developing heart would be particularly useful for studying the effects of altered gene expression on cardiac development and in the etiology of congenital cardiac anomalies. METHODS AND RESULTS: Dye studies demonstrated that intraplacental injection allows direct access to the embryonic cardiac and systemic circulation. To evaluate the efficacy of cardiac gene transfer using this approach, replication-deficient recombinant adenoviral vectors encoding luciferase or beta-galactosidase as reporter genes were injected intraplacentally into embryonic day (E)12.5 murine embryos, an age at which the mass of the heart was observed to be large compared with other organs. Embryos were assayed for transgene expression at E15.5 and at birth. Survival rates at these times were similar among vector-injected and control groups. At E15.5 and at birth, luciferase activity within the heart was 9- and 23-fold higher, respectively, than in the remainder of the embryo, although levels of expression were generally lower at birth than during embryonic life. Beta-galactosidase expression was observed within all regions of the embryonic heart and was localized to approximately 15% of atrial and ventricular cells. CONCLUSIONS: Intraplacental delivery of adenovirus at embryonic day 12.5 results in somatic gene transfer to the murine embryonic heart, which persists at least until birth. The combination of intraplacental injection to directly access the fetal coronary circulation and injection at E12.5 when the mass of the heart is large compared with other organs results in transgene expression in cardiac cells. Intraplacental injections early in embryonic life may thus be useful to study the effects of temporal manipulation of gene expression on cardiac development and disease.     

Frequency and distribution of chromosomal integration sites of the Epstein-Barr virus genome

Human lymphocytes can be transformed in vitro by integration of the Epstein-Barr virus (EBV) into the host genome. To study whether integration sites are stable or changeable in the course of long-term cultivation, three EBV-transformed lymphoblastoid cell lines, along with positive control (Namalwa cell line) and negative control (noninfected lymphocytes) cells were studied. A biotinylated Bam H1WEBV-DNA fragment was used as the probe for fluorescence in situ hybridization to count the numbers and to localize the sites of integrated EBV-DNA. Among these cell lines, the percentage of cells with integrated signals varied from 58% to 91%, with a mean of 1.43 to 2.66 signals per cell. No consistent tendency of increasing or decreasing number of signals was observed for the three cell lines harvested at four different cultivation intervals (86-204 days after infection). Although the integration was not site-specific, high frequencies of integration did occur in all three cell lines at the following chromosomal sites: 1p31, 1q31, 2q32, 3q13, 6q24 and 7q31. Because there were multiple integration sites present, it was difficult to draw any conclusion on integration site stability.     

Estrogen-nucleic acid adducts: reaction of 3,4-estrone o-quinone with nucleic acid bases

Anaphylaxis, a multisystem allergic reaction, represents a true medical emergency. Anaphylaxis is characterized by a combination of the following symptoms: urticaria, angioedema, distributive shock, and respiratory failure. Most often, the patient is rapidly treated with prompt resolution of the anaphylaxis in either the out-of-hospital or emergency department (ED) setting. Infrequently, recurrent or multiphasic anaphylaxis is encountered, involving a reappearance of allergic phenomena after complete resolution of the original reaction. Recurrence may involve nuisance-level issues such as urticaria; alternatively, multiphasic reactions may be characterized by cardiovascular collapse or respiratory compromise. Initially aggressive pharmacological therapy followed by prolonged observation in either the ED or the in-hospital setting is strongly recommended to monitor for potential recurrence.