Loss of Fas-ligand expression in mouse keratinocytes during UV carcinogenesis.

Skin cells containing excessive ultraviolet (UV) radiation-induced DNA damage are eliminated by apoptosis that involves the p53 pathway and Fas/Fas-Ligand (Fas-L) interactions. To determine whether dysregulation of apoptosis plays a role in skin cancer development through disruption of Fas/Fas-L interactions, hairless SKH-hr1 mice were exposed to chronic UV irradiation from Kodacel-filtered FS40 lamps for 30 weeks. Their skin was analyzed for the presence of sunburn cells (apoptotic keratinocytes) and for Fas and Fas-L expression at various time points. A dramatic decrease in the numbers of morphologically identified sunburn cells and TUNEL-positive cells was detected as early as 1 week after chronic UV exposure began. After 4 weeks of chronic UV exposure, these cells were barely detectable. This defect in apoptosis was paralleled by an initial decrease in Fas-L expression during the first week of chronic UV irradiation and a complete loss of expression after 4 weeks. Fas expression, however, increased during the course of chronic UV exposure. p53 mutations were detected in the UV-irradiated epidermis as early as 1 week after irradiation began and continued to accumulate with further UV exposure. Mice exposed to chronic UV began to develop skin tumors after approximately 8 weeks, and all mice had multiple skin tumors by 24 weeks. Most of the tumors expressed Fas but not Fas-L. We conclude that chronic UV exposure may induce a loss of Fas-L expression and a gain in p53 mutations, leading to dysregulation of apoptosis, expansion of mutated keratinocytes, and initiation of skin cancer.

Persistence of p53 mutations and resistance of keratinocytes to apoptosis are associated with the increased susceptibility of mice lacking the XPC gene to UV carcinogenesis.

Like xeroderma pigmentosum (XP) patients, transgenic mice lacking nucleotide excision repair (NER) genes such as XPA and XPC are extremely susceptible to ultraviolet (UV)-induced skin cancer. Because the p53 gene is an important target for UV carcinogenesis and because the p53 protein modulates NER, we investigated the consequences of NER deficiency on UV-induced p53 mutations in XPC-/- mouse skin tumors. Thirty-eight (76%) of 50 UV-induced XPC-/- skin tumor analysed displayed C-->T or CC-->TT transitions at dipyrimidine sites on the untranscribed strand of the p53 gene. A major hot spot for p53 mutation occurred at codon 270, which is also a hot spot in UV-induced skin tumors from NER-proficient C3H and SKH-hr 1 mice. Interestingly, codon 270 mutations were induced in both XPC-/- and +/+ mouse skin after 1 week of UV irradiation, but the mutations persisted only in XPC-/- mouse skin after 3 - 4 weeks of chronic UV. The persistence of UV-induced p53 mutations in XPC-/- mouse skin was associated with decreased apoptosis and increased proliferation of keratinocytes, suggesting that these events may contribute to the accelerated development of UV-induced skin tumors in XPC-/- mice.

[Evaluation of SCC antigen in patients with advanced cervix cancer treated with radiation]. / Ocena antygenu SCC u chorych na zaawansowanego raka szyjki macicy, leczonych promieniami.

The TA-4 antigen was isolated and described in 1977 by Kato and Torigoe. The antigen called SCC-squamous cell carcinoma is subfraction TA-4 isolated of liver metastases from cervix uteri. The cut-off limits for SCC-antigen is counted as 1.5-2.5 ng/ml. The level of SCC-antigen was determined in the serum of 41 women with advanced cervix uteri cancer-IIIB and IV FIGO stage. The value of SCC-antigen was evaluated twice: before and after the treatment. The increasing of SCC-level was observed in the serum of 80% women. The conclusion are: There was the lowering of SCC-antigen value in patients after the irradiation. In cases of patients who still had high SCC-antigen level after the treatment and it exceeded 8 ng/ml., progression of cancer also was found. The progression of cancer after the treatment was found in women with pretreatment level of SCC-antigen higher than 30 ng/ml.

Immunocytochemical characterization of two thyroid medullary carcinoma cell lines in vitro.

The immunocytochemical characterization of cell lines originating from thyroid medullary carcinoma, i.e. human TT cells and rat rMTC 6-23 cells, was undertaken. The immunocytochemical studies were supplemented by ultrastructural studies, including ultrastructural immunocytochemistry, and by radioimmunological estimation of calcitonin secretion to the medium. In rMTC 6-23 cells (subcultures 24 to 30), no hormone presence was demonstrated immunocytochemically, which corresponded to the absence of secretory granules at the ultrastructural level. Of various proteins sought, only neuron-specific enolase could be demonstrated. Nevertheless, the cells secreted calcitonin into the medium. TT cells (passages 145 to 160) produced secretory granules. The granules contained calcitonin, calcitonin gene-related peptide, somatostatin, neurotensin, met-enkephalin, leu-enkephalin, gastrin releasing peptide, parathyroid hormone-related protein, functional proteins of the chromogranin group and synaptophysin. Other functional proteins found in the cytosol of TT cells included non-specific enolase, calbindin and tyrosine hydroxylase. Receptor for calcitriol was localized in the cell nucleus. Marker proteins were localized in the cytosol (carcinoembryonic antigen) and in the cell skeleton (alpha-tubulin, cytokeratin). Following changes in ionized calcium levels in the medium, changes in calcitonin secretion and in immunocytochemical detectability of some hormones and functional proteins were observed. TT cells demonstrated the expression of numerous hormones and functional proteins associated with calcitonin secretion. Further, the cells in their ultrastructure, immunocytochemical and secretory characteristics, resemble more closely normal parafollicular cells of the thyroid and, in our opinion, represent a more appropriate model for functional studies.

[Combined calculation of dosage for brachytherapy and external beam therapy in radiation treatment of cervix cancer]. / Laczne obliczenia dawek z brachy i teleterapii w leczeniu radiacyjnym raka szyjki macicy.

In this paper authors present complex doses of ionizing radiation from brachytherapy and external beam therapy. Doses were determined on Computerized Planning System--Target 2 plus for patients with cancer of cervix.

Hybridocytochemical and immuno-ultrastructural study of calcitonin gene expression in cultured medullary carcinoma cells.

The study was aimed at a morphological demonstration of calcitonin (CT) gene expression in cultured TT cells, or, more specifically, hybridocytochemical detection of CT mRNA and calcitonin gene-related peptide (CGRP) mRNA and ultrastructural localization of the two hormones. The TT cells originated from medullary carcinoma of human thyroid gland. Ultrastructural studies of TT cells demonstrated a well-developed rough endoplasmic reticulum, large Golgi apparatus and low number of secretory granules. Hybridocytochemical studies showed the presence of mRNAs for CT and CGRP in all TT cells. At the ultrastructural level, double immunolabelling demonstrated that the two hormones were always expressed together in the same secretory granules. Our results provide a significant addition to the biochemical studies performed up to now and indicate that all TT cells produce both mRNAs and both hormones in parallel.

Glycoforms of alpha 1-acid glycoprotein in sera of human immunodeficiency virus-infected persons.

In acute infections thus far studied, there is a relative increase in plasma protein glycoforms rich in biantennary complex type N-glycans (type I), while in some diseases with chronic inflammatory changes, there is increase in glycoforms with more branched N-glycans (type II). In sera of 109 human immunodeficiency virus (HIV)-infected persons, 38 rheumatoid arthritis patients, and 44 healthy subjects, the composition of alpha 1-acid glycoprotein (AGP) glycoforms was studied using crossed immunoaffinity electrophoresis with concanavalin A as a ligand. In patients in CDC classifications I, II, and III, distribution of AGP glycoforms was analogous to that in normal subjects. Type I alterations were observed in patients in group IV who had no signs of arthritis. Type II changes, analogous to those found in rheumatoid arthritis, were seen in group IV patients who developed arthritis. Most significant type I changes were associated with Pneumocystis carinii pneumonia (specificity, 100%; sensitivity, 96%).

C-reactive protein and alpha-1-acid glycoprotein in monitoring of patients with chronic arterial occlusion of the lower limbs.

C-reactive protein (CRP) and alpha-1-acid glycoprotein (AGP) levels were studied in the sera of 107 patients with chronic arterial ischaemia of the lower limbs. Depending on the degree of ischaemia, patients were divided into four groups: (i) intermittent claudication--20 patients; (ii) rest pain and ankle pressure above 50 mmHg--12 patients; (iii) rest pain and ankle pressure below 50 mmHg--25 patients; (iv) peripheral necrosis--50 patients. Reconstructive surgery was performed in 84 patients and primary major amputation in 23 cases. Levels of CRP and AGP increased with the severity of ischaemia. In uncomplicated cases, CRP and AGP concentrations decreased to normal values 7-10 days after surgery. In a group of 23 patients with postoperative necrotic complications, significant increases in CRP and AGP levels were found 7-10 days after surgery. These proteins, especially CRP, may be clinically useful in monitoring patients during the postoperative period with a CRP level greater than 50 mg/l predictive of complications with a sensitivity of 83% and a specificity of 94%.

Leukemia inhibitory factor, interferon gamma and dexamethasone regulate N-glycosylation of alpha 1-protease inhibitor in human hepatoma cells.

Hepatocytes respond to inflammatory stimuli by changing the synthesis and N-glycosylation of acute phase plasma proteins (APP). So far, interleukin (IL) 6, transforming growth factor beta (TGF beta), tumor necrosis factor alpha (TNF) and IL-1 have been found to control N-glycosylation patterns of APP. Cytokines either increased (type I) or decreased (type II) the ratio of bi-relative to more branched N-glycans on APP. In this study, we describe the effect of leukemia inhibitory factor (LIF), interferon gamma (INF gamma) and dexamethasone (dex) on production of alpha 1-protease inhibitor (PI) and alpha 1-antichymotrypsin (ACT) and on glycosylation of PI in the human hepatoma cell line HepG2. Cytokines and dex were used separately and in various combinations including also IL-6 and TGF beta. Production of the antiproteases was quantitated by immunoelectrophoresis of the proteins accumulated in the culture medium. Glycosylation pattern of PI was assessed by crossed immunoaffinity electrophoresis (CIAE) with Concanavalin A (Con A) as a ligand. The production of ACT and PI was increased by LIF, decreased by INF gamma and unaffected by dex. LIF and INF gamma each like IL-6, decreased PI-Con A reactivity while dex like TGF beta enhanced PI-Con A reactivity. Combination of dex with LIF yielded additive effects while combination of dex with either INF gamma, L-6 or TGF beta acted synergistically on PI-Con A reactivity. Combinations of multiple cytokines and dex produced additive, inhibitory or synergistic effects. The type of glycosylation profile of PI secreted by HepG2 cells depended on the composition and amounts of interacting cytokines and dex.

[Influence of applicator moves to dose distribution during Selectron LDR brachytherapy]. / Wplyw przemieszczenia aplikatorów na rozklad dawki podczas radioterapii Selectronem LDR.

Irradiation of cancer diseases with intracavitary applicator makes impossible visual control of applicator's position during the process of irradiation. In this paper example applicator moves during the treatment are presented and their influence to dose distribution especially in reference points is discussed. Verification of applicator's position has been made by the use of roentgen films.

Soluble human interleukin-6-receptor modulates interleukin-6-dependent N-glycosylation of alpha 1-protease inhibitor secreted by HepG2 cells.

Interleukin-6 (IL-6) induces changes in gene expression and the N-glycosylation pattern of acute-phase proteins in hepatocytes. IL-6 exerts its action via a cell surface receptor complex consisting of an 80 kDa IL-6 binding protein (gp80) and a 130 kDa glycoprotein (gp130) involved in signal transduction. A genetically engineered gp80-derived soluble human IL-6-receptor (shIL-6-R) significantly enhanced the IL-6 effect on N-glycosylation changes (revealed by reactivity with the lectin-concanavalin A) of a1-protease inhibitor (PI) secreted by human hepatoma cells (HepG2). Stable transfection of IL-6-cDNA into HepG2 cells (HepG2-IL-6) resulting in constitutive secretion of 2 micrograms of IL-6 per 10(6) cells in 24 h led to a down-regulation of surface-bound gp80 and subsequent homologous desensitization of HepG2-IL-6 cells towards IL-6. Soluble human IL-6-R functionally substituted membrane-bound gp80 resulting in a reconstitution of responsiveness of HepG2-IL-6 cells.

C-reactive protein and alpha 1-acid glycoprotein in monitoring of patients with acute arterial occlusion.

C-reactive protein (CRP) and alpha 1-acid glycoprotein (AGP) levels were studied in sera of 75 patients with acute arterial occlusion. Depending on the degree of ischaemia, patients were divided into two groups: grade I--26 patients--and grade II--49 patients. All patients were treated surgically; 42 embolectomies, 17 endarterectomies and 16 bypasses were performed. After surgery in 19 patients various complications were observed. The concentration of both proteins at the time of admission was higher in the serum of patients with grade II than with grade I ischaemia. Similarly the concentration of both proteins was significantly higher in the sera of the patients admitted after 8 h than in patients admitted within 8 h of the onset of ischaemia. CRP and AGP levels were significantly higher in the serum of patients with ischaemia of the lower limb than in those with ischaemia of the upper limb. In all patients 2-3 days after surgery a significant increase in serum CRP and AGP was observed. In uncomplicated cases on days 7-10 the values of both proteins decreased below the level observed at the time of admission. However, in patients who experienced postoperative complications high levels of both serum proteins (especially CRP) were found on days 7-10. Complications were detected with a sensitivity and specificity of 84 and 95%, respectively, using a CRP level of 49 mg l-1 as the cut-off point.

Dose rate in irregularly shaped high energy photon beams.

A quick method of calculating the dose-rate distribution in irregularly shaped beams is presented. This method is partly based on the Cunningham model. The proposed modifications make it possible to avoid the scatter functions in favor of direct use of tissue-phantom ratios and field size coefficients. The problem has been evaluated for photons generated by 10 and 23 MV linacs. The calculated dose rates have been compared with measured ones, and good accuracy has been achieved.