| Bone-marrow cells from a patient with Bloom's syndrome cultured for 48 h in the presence of BudR exhibited a striking increase in the number of sister chromatid exchanges (SCEs) in comparison to that in the marrow cells of a patient with treated polycythemia vera (PV). Thus, it appears that an increased incidence of SCE in Bloom's syndrome occurs in various differentiated types of cells, not just blood lymphocytes, and constitutes the syndrome's most characteristic cytogenetic feature. In contrast, the incidence of SCE was not increased in marrow cells and lymphocytes of the particular PV patient studied here, whose cells did exhibit increased numbers of chromatid and chromosome gaps and breaks, presumably as result of the patient's earlier treatment. An increased frequency of SCE was demonstrated in Bloom's syndrome lymphocytes using both a technique based on BudR incorporation and one based on labeling with tritated deoxycytidine. This observation constitutes evidence against the increase of SCE being due to an unusual reaction to BudR. By conventional cytogenetic techniques, chromosome instability, including chromatid and chromosome breaks, but no homologous chromatid interchanges were also recognized in Bloom's syndrome bone-marrow cells incubated in vitro (without BudR) for either 1.k or 16 h. This observation points to the existence of chromosome instability in vivo. ( info) |
2/490. Photoinduced dermal pigmentation in patients taking tricyclic antidepressants: histology, electron microscopy, and energy dispersive spectroscopy. Two patients had been taking long-term tricyclic antidepressant therapy. Each developed a blue to slate-gray hyperpigmentation in sun-exposed areas. On histologic examination there were refractile golden brown granules free in the dermis along collagen bundles. Similar pigment was present in macrophages and along the basement membrane zone. The granules stained for melanin, but not for iron, and were bleached by the permanganate method. Electron microscopy showed varying size and shaped electron-dense granules within lysosomes and free in the dermis, which, in unstained sections, showed a less dense peripheral halo. This peripheral halo was also evident on light microscopy. Energy dispersive spectroscopy showed these granules to be rich in copper and sulfur (elements present in tyrosinase and pheomelanin, respectively). We believe that this represents a drug-melanosome complex, which is most likely caused by chronic photoactivation. ( info) |
3/490. Pseudoporphyria induced by nabumetone. Nabumetone is a nonsteroidal anti-inflammatory drug, which has only rarely been associated with photosensitivity. We report a case of bullous lesions arising over photoexposed areas in a patient treated with nabumetone. ( info) |
4/490. Pseudoporphyria induced by propionic acid derivatives. BACKGROUND: Pseudoporphyria is a photosensitive bullous skin disease that is distinguished from porphyria cutanea tarda (PCT) by its normal porphyrin profile. Drugs are a major cause of this disease, and the list of culprits is continually expanding. Nonsteroidal antiinflammatory agents (NSAIDs), especially naproxen and other propionic acid derivatives, appear to be the most common offenders. OBJECTIVE: The study was carried out to increase awareness about the etiology and characteristic features of pseudoporphyria. methods: We report two cases of pseudoporphyria caused by naproxen and oxaprozin. We review the current English language literature on this entity and discuss its clinical features, histology, ultrastructure, etiology, and pathophysiology. RESULTS: A 44-year-old man taking naproxen for chronic low back pain and a 20-year-old woman on oxaprozin for rheumatoid arthritis presented with tense bullae and cutaneous fragility on the face and the back of the hands. In both, skin biopsy showed a cell-poor subepidermal vesicle with festooning of the dermal papillae. Direct immunofluorescence revealed staining at the dermal-epidermal junction and around blood vessels with IgG in the first case and with IgG, IgA, and fibrin in the second case. urine collections and serum samples yielded normal levels of uro- and coproporphyrins. CONCLUSIONS: Most cases of pseudoporphyria are drug-induced. naproxen, the most common offender, has been associated with a dimorphic clinical pattern: a PCT-like presentation and one simulating erythropoietic protoporphyria in the pediatric population. Other NSAIDs of the propionic acid family can also cause pseudoporphyria. ( info) |
5/490. Photoallergy induced by quinidine. An 82-year-old woman presented with a lichenified dermatitis over light-exposed areas. The eruption cleared upon withdrawal of quinidine and recurred on re-administration of the drug. Though quinidine has not been recognized as a photo-sensitizing agent, upon review of the literature we have uncovered other cases which meet the criteria and justify including this drug among those capable of causing such reactions. ( info) |
6/490. Lupus erythematosus exacerbated by griseofulvin. Because griseofulvin is one of the safest systemic medications, its side effects are often forgotten. This paper serves as a reminder that griseofulvin can precipitate or exacerbate lupus erythematosus. Two patients are described: one had a photosensitivity reaction to griseofulvin which precipitated discoid LE skin lesions, without any previous evidence of LE. The other, who had known systemic LE, developed a systemic reaction, consisting of fever and malasise. ( info) |
7/490. Photolocalized tinea facialis. The case of a 34-year-old white woman with tinea facialis that persisted for nine months prior to diagnosis is presented. The confluent plaquelike erythematous eruption of the face with eyelid lichenification that flared outdoors was thought to represent polymorphic light eruption and was refractory to antibiotics, corticosteroids (topical and systemic), and antimalarials. A KOH preparation was positive when the dermatosis spilled onto the mandibular region, and restaining of the initial skin biopsy revealed fungal hyphae. Complete resolution was accomplished with griseofulvin and MicTin. tinea cab be added to the list of infectious agents that have a photosensitivity component. The fungus possibly "photolocalizes" to sun-damaged areas, ie, areas of increased capillary permeability. This case illustrates the importance of including tinea in considering diagnoses of sun-exposed lesions of the face. ( info) |
| hydroa vacciniforme is a rare, idiopathic photodermatosis with an onset in childhood and characterized by acute vesiculation, crusting and scarring following sun exposure. Familial cases are extremely rare with only one previous report. We report a brother and sister, both of whom have developed hydroa vacciniforme. ( info) |
9/490. Phytophotodermatitis due to the application of citrus hystrix as a folk remedy. We report a case of extensive phytophotodermatitis in a hiker. This was caused by the application of the juice of a member of the rutaceae family, citrus hystrix, as a folk remedy to ward off biting insects. Besides the rutaceae, plants belonging to the families Umbelliferae, moraceae and Leguminosae also contain psoralens and can cause phytophotodermatitis. In temperate countries, cases are often seen among children playing outdoors during summer, when psoralens are most abundant in wild and garden plants. ( info) |
10/490. Jessner's lymphocytic infiltrate and probable discoid lupus erythematosus occurring separately in two sisters. We describe two sisters with clinical and histological features suggestive of Jessner's lymphocytic infiltrate in one and discoid lupus erythematosus in the other. The occurrence of these two entities in one family now gives credence to the theory that Jessner's lymphocytic infiltrate is in the same disease spectrum as lupus and probably also polymorphic light eruption. ( info) |