The role of dermabrasion and chemical peels in the treatment of patients with xeroderma pigmentosum

We describe our experience with two patients with xeroderma pigmentosum who underwent periodic trichloroacetic acid chemical peels. One also received a full-face dermabrasion. The effect of chemical peeling was more transient than dermabrasion but was associated with less morbidity. Both chemical peeling and dermabrasion provided a prophylactic effect against the development of skin malignancies; the latter had a more pronounced effect.     

The relationship between chromosome damage and cell killing in UV-irradiated normal and xeroderma pigmentosum cells

It is shown that the distribution of identical amino acid residues in the primary structure of 83 non-homologous proteins containing about 14 000 amino acids is near to a casual one, i.e. it is determined by the amino acid composition. A characteristic feature of such distribution is an increased probability of a common grouping of amino acid residues.     

Alpha particle mutagenesis of human lymphoblastoid cell lines

Austria has a longstanding and eventful history in the field of radiotherapy and radiation oncology. The founder of radiotherapy, Leopold Freund, began his well-documented first therapeutic irradiation on November 24, 1896, in Vienna. He also wrote the first textbook of radiotherapy in 1903. Further outstanding Viennese pioneers in the field of radiotherapy, radiobiology, radiation physics, and diagnostic radiology include Gottwald Schwarz, Robert Kienb?ck, and Guido Holzknecht. Because many of the leading Austrian radiologists had to emigrate in 1938, irreparable damage occurred at that time for the medical speciality of radiology. After World War II, the recovery in the field of radiotherapy and radiation oncology started in Austria in the early sixties. Eleven radiotherapy centers have been established since that time, and an independent society for radio-oncology, radiobiology, and medical radiophysics was founded in 1984. Finally, in March 1994, radiotherapy-radio-oncology became a separate clinical specialty.     

High mutation frequency in ras genes of skin tumors isolated from DNA repair deficient xeroderma pigmentosum patients

Xeroderma pigmentosum (XP) patients are clinically characterized by a very high incidence of skin cancers on exposed skin, at an early age. XP cells in vitro are strongly deficient in excision-repair and highly mutagenized by UV light. We were, therefore, interested in measuring mutation frequency and in determining mutation spectra in patients' tumors exposed to UV lesions. We chose to look at oncogene activation in skin tumors with the idea that more mutations, particularly of the ras gene family, would be found in XP tumors where lesions remain unrepaired compared to normal individuals. Our results clearly show that more than a 2-fold significantly higher mutation frequency (50%) of the ras genes was found in XP in contrast to control tumors (22%). The majority of the mutations were found at codon 12 of all three ras genes with a preponderance for N-ras in XP samples. The mutation spectra indicate that all mutations found were located opposite pyrimidine-pyrimidine sequences which represent a hot spot for UV-induced DNA lesions. Most of the mutations were of the type expected from studies performed in vitro with model systems. This high mutation frequency in XP was accompanied by a very high level of Ha-ras and c-myc gene amplification and rearrangement. All these data are consistent with a fundamental role of unrepaired UV-induced DNA lesions as an initiating event in human skin tumors on exposed parts of the body.     

Colony-forming ability of ultraviolet-irradiated xeroderma pigmentosum fibroblasts from different DNA repair complementation groups

In two related studies, a combination of reinforcement for incompatible behavior and positive practice overcorrection was applied to the elimination of head-slapping and head-banging behavior exhibited, respectively, by two profoundly retarded boys. The design for both studies also included a period in which only reinforcement for incompatible behavior was applied. The results from Study 1 indicated that, while reinforcement had little effect in reducing the frequency of the learner's head slapping, the combination of reinforcement and overcorrection had an immediate effect in significantly reducing and eventually eliminating that behavior. A 4-month follow-up indicated no significant recurrence of the behavior. In Study 2, on the other hand, both reinforcement and the combination of reinforcement and overcorrection resulted in a significant increase in the frequency of the learner's head-banging behavior. Discussion centered on several research questions left unanswered by the differing effects of the procedures applied in both studies.     

Mutation and expression of the XPA gene in revertants and hybrids of a xeroderma pigmentosum cell line

Achalasia is characterized by failure of relaxation of the lower esophageal sphincter and absence of progressive peristalsis in the esophageal body. Few data are available regarding the morphologic features of achalasia, in particular its histologic progression. The esophagi of 42 patients with achalasia treated with total thoracic esophagectomy were examined histologically in order to systematically identify morphologic features of clinically unresponsive achalasia and to determine what could be learned about the disease's evolution. In all cases, myenteric ganglion cells within the esophageal body were markedly diminished, with 20 specimens having none. Twenty specimens had residual ganglion cells in the proximal esophagus, and 15 specimens had a few randomly distributed ganglion cells in the mid- and distal portions of the esophagus. Inflammation within myenteric nerves, present in all cases, generally consisted of a mixture of lymphocytes and eosinophils, occasionally with plasma and mast cells. Focal replacement of myenteric nerves by collagen occurred in all cases, and there was almost complete replacement in several cases. Actual destruction of the residual ganglion cells was not seen. The resected esophagi also shared extramyenteric morphologic features. Some features probably stemmed from physiologic obstruction, such as muscular hypertrophy, mainly of the muscularis propria (all cases), with secondary degeneration and fibrosis (29 cases), and eosinophilia of the muscularis propria (22 cases). Other changes, probably resulting from chronic stasis of ingested materials in the lumen, included diffuse squamous hyperplasia (all cases), lymphocytic mucosal esophagitis (28 cases), lymphocytic inflammation of the lamina propria and submucosa with prominent germinal centers (all cases), and submucosal periductal or glandular inflammation with complete loss of submucosal glands in half of the cases. One patient had high-grade squamous dysplasia, and another had superficially invasive squamous cell carcinoma. A third group of changes was probably due to previous esophagomyotomy, including abnormal gastroesophageal reflux, as shown by pH reflux testing (13 cases) and Barrett's mucosa (four cases). In one case of Barrett's there was low-grade dysplasia. Clinically unresponsive, surgically resected achalasia has almost total loss of ganglion cells, and widespread destruction of myenteric nerves has already occurred. The only active component is myenteric inflammation. However, it cannot be determined whether this inflammation is a manifestation of ongoing nerve destruction or whether it is a secondary phenomenon.     

Induction of sister chromatid exchanges in fibroblasts from normal donors and from patients with xeroderma pigmentosum after combined treatment with ultraviolet radiation and modulated low frequency electric currents

Dermal fibroblasts derived from normal donors as well as from patients with xeroderma pigmentosum (XP) were exposed in vitro to ultraviolet radiation of 254 nm wavelength and to weak electric 4, 000 Hz currents modulated in amplitude with 50 Hz. Treatment with this so-called interferential current (IFC) increased the rate of sister chromatid exchanges (SCE) in all fibroblast types up to roughly 50% above the spontaneous level. When IFC was applied in combination with UV-radiation, it lowered UV-induced increase of the SCE-rate. A reduction of UV-induced SCEs was seen when XP-cells were exposed to IFC prior to UV-treatment, compared to the reverse order of treatment. The order of exposure has only been analysed in 5 XP patients, not in normal donors. The relationships between different combinations of exposure parameters (IFC-amperage, UV-dose, cell pathology, order of treatment) were examined by analysis of variance (ANOVA).     

Defective bypass replication of a leading strand cyclobutane thymine dimer in xeroderma pigmentosum variant cell extracts

Xeroderma pigmentosum variant (XP-V) is an inherited disorder resulting in hypersensitivity to the cytotoxic, mutagenic, and carcinogenic effects of UV light. There is evidence suggesting that XP-V cells carry a defect in the replication of UV-induced DNA damage, leading to mutations in genes, e.g., proto-oncogenes and tumor suppressor genes, of exposed skin cells. Using an in vitro assay to quantitatively evaluate replication of the most prevalent UV-derived DNA lesion, the cis,syn-thymine dimer (T x T), we have recently found that a T x T located on the leading strand can be bypassed by a bona fide human replication fork but can also induce fork uncoupling with selective synthesis of the undamaged lagging strand (D. Svoboda and J-M. Vos, Proc. Natl. Acad. Sci. USA, 92: 11975-11979, 1995). We now report the application and further refinement of this sensitive assay to the replication of a T x T-containing template by XP-V cell-free extracts. In comparison to normal controls, a 10-26-fold deficiency in the bypass replication of T x T was observed in XP-V cell extracts. In contrast, the disease extracts were as competent as controls for replication of the undamaged TT plasmid and for leading T x T-induced fork uncoupling. Besides mismatch repair and nucleotide excision repair, the bypass replication defect of XP-V may represent a novel category of hereditary mutator phenotypes affecting DNA damage processing.     

Hypomethylation of classical satellite DNA and chromosome instability in lymphoblastoid cell lines

To determine possible relationships between DNA hypomethylation and chromosome instability, human lymphoblastoid cell lines from different genetic constitutions were studied with regard to 1) uncoiling and rearrangements, which preferentially affect the heterochromatic segments of chromosomes 1 and 16; 2) the methylation status of the tandemly repetitive sequences (classical satellite and alphoid DNAs) from chromosomes 1 and 16, and of the L1Hs interspersed repetitive sequences. The methylation status largely varied from cell line to cell line, but for a given cell line, the degree of methylation was similar for all the repetitive DNAs studied. Two cell lines, one obtained from a Fanconi anemia patient and the other from an ataxia telangiectasia patient were found to be heavily hypomethylated. The heterochromatic segments of their chromosomes 1 and 16 were more frequently elongated and rearranged than those from other cell lines, which were found to be less hypomethylated. Thus, in these lymphoblastoid cell lines, alterations characterized by uncoiling and rearrangements of heterochromatic segments from chromosomes 1 and 16 seem to correlate with the hypomethylation of their repetitive DNAs. Two-color in situ hybridizations demonstrated that these elongations and rearrangements involved only classical satellite-DNA-containing heterochromatin. This specificity may be related to the excess of breakages affecting the chromosomes carrying these structures in a variety of pathological conditions.     

Expression of human placental cell surface antigens on peripheral blood lymphocytes and lymphoblastoid cell lines

The expression of human placental cell surface antigens was examined in cells of lymphoid origin, including peripheral blood lymphocytes and cultured lymphoblastoid cells of bone marrow or thymus derivation. A select group of this defined set of surface antigens was detected on all three cell preparations. The most remarkable observation was the conspicuous absence of three subunits previously demonstrated to be present on all human cell surfaces examined to date. Antiserum directed against several placental components prevents adhesion and spreading of cells which grow attached to surfaces. These results suggest a role for these three glycoproteins in mediating cellular adhesion.     

Human xeroderma pigmentosum group A protein interacts with human replication protein A and inhibits DNA replication

Human replication protein A (RPA; also known as human single-stranded DNA binding protein, or HSSB) is a multisubunit complex involved in both DNA replication and repair. While the role of RPA in replication has been well studied, its function in repair is less clear, although it is known to be involved in the early stages of the repair process. We found that RPA interacts with xeroderma pigmentosum group A complementing protein (XPAC), a protein that specifically recognizes UV-damaged DNA. We examined the effect of this XPAC-RPA interaction on in vitro simian virus 40 (SV40) DNA replication catalyzed by the monopolymerase system. XPAC inhibited SV40 DNA replication in vitro, and this inhibition was reversed by the addition of RPA but not by the addition of DNA polymerase alpha-primase complex, SV40 large tumor antigen, or topoisomerase I. This inhibition did not result from an interaction between XPAC and single-stranded DNA (ssDNA), or from competition between RPA and XPAC for DNA binding, because XPAC does not show any ssDNA binding activity and, in fact, stimulates RPA's ssDNA binding activity. Furthermore, XPAC inhibited DNA polymerase alpha activity in the presence of RPA but not in RPA's absence. These results suggest that the inhibitory effect of XPAC on DNA replication probably occurs through its interaction with RPA.     

Transcriptional analysis of Marek''s disease virus (MDV) genes in MDV-transformed lymphoblastoid cell lines without MDV-activated cells

Prevention of the occurrence of diabetes-specific vascular complications is the final aim of clinical islet transplantation. Pancreatic islets isolated from adult pigs may be a suitable tissue source to transplant a large number of type 1 diabetic patients. Acute cellular rejection may be finally overcome by clinically applicable protocols for tolerance induction. However, primary nonfunction of the graft, as regularly observed in the porcine islet-to-rat xenotransplantation model, may be an additional problem. In this paper, species-specific inflammatory and immunological mechanisms are discussed which prevent early porcine islet graft function in rats but not in mice.     

Nicotinamide-adenine dinucleotide phosphate oxidase assembly and activation in EBV-transformed B lymphoblastoid cell lines of normal and chronic granulomatous disease patients

This paper deals with the mechanisms of activation of NADPH oxidase investigated using EBV-transformed human B lymphoblastoid cell lines (B cells) from normal subjects and from patients affected by X-linked chronic granulomatous disease (CGD). The results reported are as follows. 1) In normal B cells, the NADPH oxidase components p67phox, p40phox, p22phox, and gp91phox were less expressed than in polymorphonuclear neutrophils. 2) In normal B cells stimulated with PMA, p47phox, p67phox, and p40phox translocated to the membranes as occurs in polymorphonuclear neutrophils. 3) In CGD, B cells expressing p22phox in the absence of gp91phox, p47phox, p67phox, and p40phox did not translocate to the membranes after stimulation with PMA. 4) In PMA-stimulated B cells from an X91+ CGD patient in which p22phox was normally expressed and gp91phox was present but lacked five amino acids, translocation of p47phox to the membranes was unaffected, but p67phox and p40phox were poorly translocated, and the production of O2- was greatly reduced with respect to that by normal B cells. Taken together, these findings indicate that 1) a low expression of some NADPH oxidase components may represent the molecular basis of the low production of O2- in B lymphocytes; 2) the cytosolic components of NADPH oxidase cannot bind to p22phox on the membranes in the absence of gp91phox; 3) p47phox can translocate to the membranes independently of p67phox and p40phox; and 4) gp91phox may have a role in mediating and/or stabilizing the binding of p67phox and p40phox to the membranes of activated cells.     

Inheritance of abnormal expression of SOS-like response in xeroderma pigmentosum and hereditary cancer-prone syndromes

The time course of induction of SOS-like stress responses such as enhanced reactivation (ER) and enhanced mutagenesis (EM) has been investigated in UV-C-irradiated skin fibroblasts from a xeroderma pigmentosum (XP) family, using herpes simplex virus type 1 as a probe. Similar ER studies were performed in a Li-Fraumeni syndrome (LFS) family and in a family with a high incidence of breast, ovarian, and colon cancer. In two XP (complementation group B) patients, with a striking absence of skin tumors even at an age of >40 years, only induction of EM was observed, whereas ER was absent (XPER-). The ER- phenotype was inherited from the father, whereas cells from the mother exhibited normal expression of ER and EM. This suggests that the absence of ER is a hereditary trait that is not correlated with a repair-deficient phenotype. Abnormally high levels of ER were observed in UV-C-exposed skin fibroblasts from rive LFS patients. The inheritance of the ER response was studied in one LFS family. High levels of ER were observed only in cells derived from affected individuals carrying one mutated p53 allele, whereas cells from unaffected family members, carrying two wild-type p53 alleles, exhibited normal ER levels. This result shows that abnormally high levels of ER positively correlate with the occurrence of cancer in affected individuals from a LFS family. Interestingly, abnormally high levels of ER were observed in cells from afflicted as well as from unafflicted members of a family with a high incidence of breast, ovarian, colon, and stomach cancer. This suggests that these latter individuals have inherited a mutated, putative predisposing gene, resulting in abnormal expression of ER, but that cancer had not yet developed. The results indicate that the ER response can possibly be used as a prognostic marker to identify carriers in various hereditary cancer-prone syndromes at an early age.     

Lymphocytes' cytotoxicity towards cells of human lymphoblastoid lines in patients with rheumatoid arthritis and systemic lupus erythematosus

A research study and discussion of antiinterferon immunoglobulin in the treatment of rheumatoid arthritis and systemic lupus erythematosus, and its possible value in the treatment of allergic diseases, autoimmune diseases and other diseases where it is presumed there may be an autoimmune genesis.