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Biomedical subjects

L Paolini

Publications and source records attributed to L Paolini.

6 recordsLinked to original sources

Phenolphthalein-induced toxic epidermal necrolysis.

OBJECTIVE: To report a case of phenolphthalein-induced toxic epidermal necrolysis (TEN) in a patient maintained on several other medications more commonly known to be associated with TEN. CASE SUMMARY: A 78-year-old white man presented with intractable lower back pain and constipation. On day 1 of admission, the patient exhibited a diffuse urticarial rash over his trunk and extremities. History revealed that the patient had taken a combination phenolphthalein/docusate sodium (Correctol) over-the-counter laxative 1 day prior to admission. He had a similar urticarial rash 1.5 years earlier with this product and was instructed not to use it. A biopsy was performed and evidence from light microscopic analysis of the tissue led to a diagnosis of TEN. Furosemide, spironolactone, allopurinol, and hydroxyurea were considered possible causes of the reaction and were discontinued. Despite this, the lesions worsened in severity. The patient subsequently responded well to intravenous antibiotics, intravenous corticosteroids, and local wound care. Furosemide, spironolactone, hydroxyurea, allopurinol, and docusate were all reintroduced without reactivation of the lesions. DISCUSSION: Phenolphthalein is the active ingredient in several over-the-counter laxative preparations and has only rarely been reported to cause TEN. (It is no longer contained in Correctol.) To our knowledge, this case report represents only the third description of laxative-induced TEN. Although this patient had been exposed to several other medications more commonly associated with TEN, his long-term tolerance of and uneventful rechallenge with these medications exclude them as potential catalysts to this drug reaction. The patient's previous rash and the temporal relation of this event and the ingestion of phenolphthalein, as well as the similarity of this case to other reports, point to phenolphthalein as the cause of TEN in this patient. CONCLUSIONS: TEN is a rare disorder that can be fatal in up to 30% of patients. Clinicians should include phenolphthalein in their list of possible causes of drug-induced TEN. A careful and complete medication history can help avoid unnecessary discontinuation of clinically important medications and inadvertent rechallenge with the causative agent.

Aged↗

Hydroxychloroquine toxicity despite normal dose therapy.

The risk of retinopathy associated with the use of hydroxychloroquine is said to be nullified if the dosage recommendations are followed strictly. In this case report, we describe an elderly patient with rheumatoid arthritis who had bilateral maculopathy, presumably secondary to hydroxychloroquine therapy, despite a dosing regimen within therapeutic guidelines. We believe special attention should be given to elderly patients who are being treated with hydroxychloroquine because their retinal pigment epithelium may be more susceptible to the toxic effects of this drug.

Aged↗

Factors affecting amplification of BK virus episomal vectors in human cells. Brief report.

Analysis of factors determining replication of BK virus (BKV) episomal vectors in human cells showed that vector copy number was related to the level of BKV T antigen expression. T antigen was synthesized efficiently, as assessed by indirect immunofluorescence, in vector-transfected primary embryonic fibroblasts undergoing neoplastic transformation. Surprisingly, transfected continuous cell lines (143 B, HeLa and KB), kept under biochemical selection or tested in transient assays, produced negligible amounts or no T antigen, revealed only by a sensitive ELISA test, suggesting that in these cells vector amplification was under the control of cellular factors. Presence or absence of BKV late region sequences, BKV strain, orientation of the inserted genes and presence or absence of selection were not relevant for vector replication. Type of biochemical selection, however, was important, since BKV vectors containing the thymidine kinase gene replicated better than those containing the neo gene. Despite great variability, vector copy number increased in transfected clones of adenovirus 5-transformed 293 cells, in the absence of immunofluorescence detectable T antigen. These cells express adenovirus immediate early proteins E1A and E1B which may directly or indirectly activate BKV origin of replication.

Antigens, Polyomavirus Transforming↗

Suppression of BK virus replication and cytopathic effect by inhibitors of prokaryotic DNA gyrase.

Nalidixic acid and oxolinic acid, two antibacterial agents known to inhibit bacterial DNA gyrase, are shown to suppress the replication, as well as the cytopathic effect, of BK virus in Vero cell cultures. The inhibition of virus replication was detectable at day 4 post infection in cultures which had been continuously exposed to drugs at concentrations as low as 0.02 to 0.04 mM of nalidixic acid and 0.2 mM of oxolinic acid. These active concentrations are inferior to plasma levels attained in the course of clinical use of the drugs for antibacterial chemotherapy. Also, under these circumstances, no cytotoxicity occurred. The inhibition of development of cytopathology and of virus-induced cell death was demonstrable in cultures treated for 12 days with the drugs. Under these circumstances of prolonged action, oxolinic acid proved to be slightly cytotoxic in that virus inhibitory doses reduced the viability of normal cells. No alterations in the topological conformation of the viral genome or accumulation of end products of viral DNA replication were detected. However, accumulation of viral DNA form I at 48 h post infection suggests that the drugs act through a mechanism involving DNA topoisomerase.

Antigens, Viral↗