Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0043346 (xeroderma pigmentosum)
 2,924 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

UV-sensitivity is a common feature of several diseases including Xeroderma pigmentosum (XP), Cockayne syndrome (CS) and Bloom syndrome (BS). In 12 children with such diseases, cell viability and DNA repair following UV-irradiation as well as PHA transformation of lymphocytes were studied. In 5 of 6 XP cases, in 1 child with CS and in 1 of 2 children with BS, DNA repair and PHA transformation of lymphocytes showed extremely depressed values. A similar study was performed in 2 children with a rare association of XP and CS. Results suggest a relationship between these 2 diseases
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PMID:[Photosensitization and DNA repair. Possible nosologic relationship between Xeroderma pigmentosum and Cockayne's syndrome]. 74 55

Oral administration of isotretinoin (13-cis retinoic acid) was shown previously (Kraemer, K. H., J. J. DiGiovanna, A. N. Moshell, R. E. Tarone, and G. L. Peck. 1988. N. Engl. J. Med. 318:1633-1637) to reduce the frequency of skin cancers in xeroderma pigmentosum (XP) patients. The mechanism of protection was unclear. In the present study, x-ray-induced chromatid damage in PHA-stimulated blood lymphocytes from five XP patients receiving isotretinoin was approximately half that in blood samples from the same patients before or subsequent to treatment. The x-ray-induced chromatid damage in blood lymphocytes from a normal control was reduced significantly by cocultivation with blood or plasma from an XP patient receiving isotretinoin or by addition of 10(-6) M isotretinoin to cultures 1 h before x-irradiation. A similar reduction in x-ray-induced chromatid damage was reported previously by adding to the culture medium, mannitol, a scavenger of the free hydroxyl radical, or catalase, which decomposes hydrogen peroxide; both of these products are generated during ionizing radiation. The present observations suggest that isotretinoin acts as a scavenger of such radiation products, thereby providing protection against x-ray-induced chromatid damage.
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PMID:Retinoid protection against x-ray-induced chromatid damage in human peripheral blood lymphocytes. 143 Feb 30

There is evidence for defective DNA repair in xeroderma pigmentosum, Cockayne's syndrome, and trichothiodystrophy, but for increased cancer risk only in xeroderma pigmentosum. Natural and adaptive immune surveillance and mutant frequency to 6-thioguanine resistance in circulating T-lymphocytes were studied in five patients with xeroderma pigmentosum, two with Cockayne's syndrome, and one with trichothiodystrophy. Forty-eight-hour cutaneous hypersensitivity responses to recall antigens excluded anergy and circulating CD3+, CD4+, CD8+, and CD16+ cell numbers were within normal limits in all patients tested, as were proliferative lymphocyte responses to PHA, except in the trichothiodystrophy patient. Proliferative responses to recall antigens (PPD, SKSD, and Candida) showed that all patients responded to one or more antigens. Direct natural killer cytotoxicity measured against the human erythromyeloid leukaemia cell line K562 using a 4-h 51Cr release assay was significantly reduced in xeroderma pigmentosum (specific cytotoxicity less than mean +/- SD greater than 17.4 +/- 9.4 per cent, with effector:target cell ratio of 50:1) compared to normal controls (45.8 +/- 17.8), but normal in Cockayne's syndrome and trichothiodystrophy. Generation of lymphokine activated killer cell activity was normal in the two xeroderma pigmentosum lines tested. The mutant frequency in the xeroderma pigmentosum donors was significantly increased (p less than 0.01) and was elevated in the two Cockayne's syndrome donors, taking age into account. No mutants were observed from the single trichothiodystrophy donor. These findings suggest that reduced natural killer cell activity may contribute to the greatly increased susceptibility to skin cancer in xeroderma pigmentosum.
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PMID:Immune function, mutant frequency, and cancer risk in the DNA repair defective genodermatoses xeroderma pigmentosum, Cockayne's syndrome, and trichothiodystrophy. 238 95

The distribution of spontaneous sister chromatid exchanges (SCEs) was studied in PHA-stimulated lymphocytes from 15 patients affected by xeroderma pigmentosum (XP). The study of unscheduled DNA synthesis (UDS) in twelve of these patients showed that seven were deficient and five proficient. The number of SCEs in XP patient cells was higher than in those of 19 controls, and the distributions of SCEs per cell were significantly different. However, the results varied when XP patients were considered in relation to their UDS: the group of XP patients with proficient UDS did not differ, whereas the group of XP patients with deficient UDS was very significantly different from controls. The group not tested for UDS was similar to the deficient UDS group. The possible relationship between the increase of SCEs and the type of DNA repair defect is discussed.
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PMID:Increase of sister chromatid exchanges in excision repair deficient xeroderma pigmentosum. 292 Oct 29

UV-induced unscheduled DNA synthesis has been studied in lymphocytes of healthy donors and of Xeroderma pigmentosum patients (the classic form, and a form with an increased sensitivity to gamma-ray). In order to study the influence of PHA-induced differentiation on repair capacity of cells, lymphocytes were cultured in the presence or in the absence of PHA. The data obtained show that PHA-induced differentiation of human lymphocytes leads to an increase in the intensity of repair after UV-irradiation of these cells, and, accordingly, the repair is completed in a shorter time. In the case of the classic form of Xeroderma pigmentosum, the effect of differentiation on the repair level is more distinct, but no effect is observed in cells of Xeroderma pigmentosum sensitive both to UV and gamma-ray.
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PMID:[DNA repair in the UV irradiation of human peripheral blood lymphocytes (healthy donors and xeroderma pigmentosum patients) in relation to the dedifferentiation process in phytohemagglutinin exposure]. 647 76

A study was made of the effects of a chemical mutagen of the "gamma-type"--methylmethansulfonate (MMS) and of mutagen of the "UV-type"--4-nitroquinolin-1-oxide (NQO) and 7-brommethylbenz(alpha)antracen (BMBA) exerted on chromosome aberration frequency in lymphocytes of patients with classical Xeroderma pigmentosum and with a so-called form II of the disease on different stages of the cell cycle. Mutagens were added to PHA stimulated lymphocyte cultures every 3 hours, simultaneously with pulse 3H-thymidine labelling, to fix the stage of the cell cycle at the moment of treatment. NQO and BMBA treatments were found to increase the frequency of chromosome aberrations in classical XP cells, whereas MMS was not found to. In the XP II cells, defective in repair of both UV and gamma damaged DNA, chromosome aberrations yield is higher than in normal cells after all the three mutagens treatment. The data obtained show the correlation between DNA repair and chromosome aberrations yield.
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PMID:[Number of chromosome aberrations induced by chemical carcinogens in the cells of patients with 2 forms of xeroderma pigmentosum]. 676 81