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Biomedical subjects

P Fiallo

Publications and source records attributed to P Fiallo.

16 recordsLinked to original sources

Acrokeratoelastoidosis of Costa: a primary disease of the elastic tissue?

A 24-year-old black woman from Uganda was seen for treatment of multiple papules on her hands and feet. The lesions corresponded microscopically to foci of hyperkeratosis and acanthosis. Acid orcein stain revealed marked elastic fiber fragmentation. Acrokeratoelastoidosis of Costa (AKE) was diagnosed. The same damage to the elastic fibers was also present in an additional specimen from grossly uninvolved skin. On electron microscopy there were pronounced changes of the elastic fibers with elastolysis in both specimens. This case with generalized damage of the dermal elastic tissue supports the view that elastorrhexis is the key feature of AKE. Accordingly, the disease could be regarded as a primary elastic tissue disorder. The marginal acral keratoderma that is seen in AKE patients could represent epidermal changes secondary to chronic trauma.

Adult

beta 2-Glycoprotein I-dependence of anticardiolipin antibodies in multibacillary leprosy patients.

This study was undertaken to investigate the influence of beta 2-glycoprotein I (GPI) on anticardiolipin antibody (aCL) titration in leprosy. The study group consisted of 140 sera from patients with multibacillary leprosy (46 borderline, 94 lepromatous). The group included newly diagnosed, previously untreated patients, patients under treatment and patients released from treatment. GPI addition enhanced significantly the aCL titres in sera from lepromatous leprosy but not in those from borderline leprosy. Moreover, when the patients were classified according to their bacteriological status, aCL titres were found to be significantly higher in skin smear positive patients compared to bacteriologically negative patients. Thus, the present study demonstrates that aCL in multibacillary leprosy patients are mainly of the GPI-dependent type and emphasizes the importance of GPI addition for aCL titration in leprosy.

Analysis of Variance

Short report: erythema nodosum leprosum lymphadenitis.

A case of isolated erythema nodosum lymphadenitis involving the paravertebral, intercostal, and cervical lymph nodes without concomitant skin involvement is reported in a 62-year-old male patient under treatment for lepromatous leprosy.

Erythema Nodosum

Detection of p53 and histopathological classification of skin tumours induced by halogen lamps in hairless mice.

Skin lesions induced by exposure of three strains of female hairless mice to the light emitted by uncovered halogen quartz lamps were subjected to histopathological analysis. We examined 170 representative specimens out of a total of 597 skin lesions, i.e. 38 out of 74 SKH-1 mice, 110 out of 472 MF-1 mice, and 42 out of 51 C3H mice. The results provided evidence of various types of alterations, including preneoplastic changes, such as epidermal hyperplasia, and benign tumours, such as papillomas, as well as tumours with an increasing degree of malignancy, i.e., keratoacanthoma-like tumours, appendage/basal tumours, actinic keratoses/carcinomas in situ, and squamocellular carcinomas. SKH-1 was the most sensitive strain to the far-ultraviolet wavelengths delivered by halogen lamps, as shown not only by the shortest latency time and the highest multiplicity of skin lesions but also by the highest frequency of malignant tumours. Some areas of atypical melanocyte proliferation were only detected in C3H pigmented mice. Eighty-two of the lesions excised from MF-1 mice were additionally examined for p53 protein by immunohistochemical methods. Formalin-fixed, paraffin-embedded sections and frozen sections were analyzed in parallel by using polyclonal CM-1 antibody and monoclonal PAb240 antibody, respectively. A positive response for p53 was only observed in squamocellular carcinomas, and was related to the size of cancers; in fact, six out of 10 cancers of 10-30 mm in diameter were positive, whereas all 16 cancers of 2-9 mm in diameter were negative. All six positive squamocellular carcinomas were detected by using the CM-1 antibody, which recognizes both wild-type and mutant forms of p53 protein, and five of them were also positive with the PAb 240 antibody, which only recognizes the mutant form. Thus, p53 mutation appears to be a late event in the development of halogen-induced skin tumours in hairless mice, requiring a severe degree of malignancy and an advanced stage of the neoplastic mass growth.

Animals

Detection of Mycobacterium leprae and the potential for monitoring antileprosy drug therapy directly from skin biopsies by PCR.

An improved protocol for PCR analysis of Mycobacterium leprae-infected tissues, based on enzymatic lysis, has been developed and used to demonstrate the feasibility of using PCR for detecting M. leprae in routine skin biopsies taken from leprosy patients throughout the clinical spectrum. Of 92 multibacillary patients tested, 99% were PCR-positive using gel electrophoresis or DNA hybridization to detect the amplified product. Similar analysis of paucibacillary patients, in which only one of 27 biopsies had demonstrable AFB microscopically, gave a positivity rate of 74%. No PCR signals were demonstrated from skin biopsies from seven patients with non-leprosy dermatoses and one AIDS patient with a disseminated atypical mycobacteriosis. Evaluation of leprosy patients with antileprosy drug therapy prior to biopsy demonstrated that PCR signals were either greatly diminished or absent after 2 months of continuous antibiotic therapy. PCR was also able to detect the presence of M. leprae in tissues of patients receiving antibacterial therapy when patients were suspected of harbouring drug-resistant M. leprae.

Anti-Bacterial Agents

Effects of fixation on polymerase chain reaction detection of Mycobacterium leprae.

The effects of standard fixatives (10% neutral buffered formalin, ethanol and mercury based) on the detection of Mycobacterium leprae DNA by the polymerase chain reaction (PCR) were studied. Mercury-based fixatives (Zenker's and Carnoy-Lebrun's fluids) strongly inhibited PCR amplification of M. leprae DNA. Ten percent neutral buffered formalin was inhibitory, but significant inhibition was observed only when fixation times exceeded 24 h. Ethanol-based fixatives provided the best medium for holding specimens for subsequent PCR with both free bacilli and skin biopsy specimens containing M. leprae. The M. leprae-specific, 360-bp region of the 18-kDa protein gene could be amplified from paraffin-embedded sections of formalin-fixed skin biopsy specimens from patients with either multibacillary or paucibacillary infections when proper fixation conditions were used. Results of the study demonstrate that tissues properly fixed with two standard fixatives (10% neutral buffered formalin and 50 or 70% ethanol) can be analyzed by PCR for the presence of M. leprae with no loss in specificity and only minimal diminution in sensitivity compared with the specificities and sensitivities obtained by use of freshly prepared, unfixed specimens.

Animals