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N Cameli

Publications and source records attributed to N Cameli.

At least 19 recordsLinked to original sources
PubMed2001

Studies on the photostability and in vitro phototoxicity of Labetalol.

The purpose of this study was to obtain information on the photochemical and phototoxic properties of Labetalol, a beta-blocker drug. Preliminary information on the drug photoreactivity was achieved using a flow system with a photochemical reactor on-line with a diode array detection system. Photophysical and photochemical investigations on the drug were performed in aqueous solutions at different pH values using spectrophotometric and fluorimetric methods; the photodegradation quantum yield was found to be 2.7 x 10(-3) at pH 5.8 and 1.5 x 10(-2) at pH 11.5. Forced photodegradation of labetalol solutions under exposure to UVA--UVB radiations (xenon arc lamp) was monitored by reversed-phase liquid chromatography. The main photodegradation products were isolated and characterized by NMR and mass spectrometry; labetalol was found to give 3-amino-1-phenylbutane and salicylamide-4-carboxaldehyde as the main photoproducts. Preliminary phototoxic testings on human keratinocyte cultures were performed evaluating the viability of the cells by the neutral-red uptake assay; mutagenic and photomutagenicity tests were also carried out based on Salmonella typhimurium strains. As a result, labetalol was found to be photolabile,mainly in alkaline medium, but evidences of significant phototoxic and photomutagenic effects by the drug were not observed.

3T3 Cells↗
PubMed2000

Onychomatricoma: report of three cases, including the first recognized in a colored man.

Onychomatricoma is an uncommon benign tumor of the nail matrix with typical clinical features. We report here 3 cases of onychomatricoma, including the first case in a black patient. In all three patients a presumptive diagnosis of onychomatricoma was made by clinical examination. The affected nails were thickened and showed a marked overcurvature of the nail plate. Frontal view of the nail revealed the presence of small woodworm-like cavities within the nail plate. In all cases the pathology showed multiple fibroepithelial projections that extended into the thickened nail plate. The tumor epithelium was identical to that of the normal nail matrix and keratinized without a granular layer.

Adult↗
PubMed1999

Storiform collagenoma of the nail.

The term circumscribed storiform collagenoma was coined by Maize et al in 1989 to describe four dermal fibromas with pathologic features resembling the sclerotic fibromas associated with Cowden's disease. We report a subungual nodule with the pathologic features of circumscribed storiform collagenoma in a patient without Cowden's disease.

Adult↗
PubMed1998

Calcipotriol ointment in nail psoriasis: a controlled double-blind comparison with betamethasone dipropionate and salicylic acid.

This double-blind randomized study was designed to compare the efficacy and safety of calcipotriol ointment (50 microg/g) with betamethasone dipropionate (64 mg/g) and salicylic acid (0.03 g/g) ointment in the treatment of nail bed psoriasis. Fifty-eight patients applied the given drug to the affected nails twice a day for 3-5 months, depending on clinical response. Efficacy was assessed monthly on the basis of nail thickness, measured in millimetres. Photographs of the treated nails were taken at baseline, and after 3 and 5 months. Tolerability was assessed at 3 and 5 months. In patients with fingernail psoriasis, after 3 months of treatment subungual hyperkeratosis was reduced from 2.3 +/- 0.1 mm (mean +/- SEM) to 1.5 +/- 0.1 mm (-26.5%) in the calcipotriol group and from 2.3 +/- 0.1 mm to 1.6 +/- 0.1 mm (-30.4%) in the betamethasone dipropionate and salicylic acid group [not significant (NS) between treatments, analysis of variance (ANOVA)]. After 5 months, responders showed a 49.2% reduction in hyperkeratosis in the calcipotriol group (from 2.8 +/- 0.1 mm to 1.4 +/- 0.2 mm) and 51.7% (from 2.1 +/- 0.1 mm to 1.0 +/- 0.1 mm) in the betamethasone dipropionate and salicylic acid group (P < 0.001 from baseline, NS between treatments, ANOVA). In patients with toenail psoriasis, after 3 months of treatment there was an overall reduction in hyperkeratosis from 2.6 +/- 0.1 mm to 2.1 +/- 0.1 mm (-20.1%) in the calcipotriol group and from 3.0 +/- 0.1 mm to 2.3 +/- 0.1 mm (-22. 9%) in the betamethasone dipropionate and salicylic acid group (P < 0.001 from baseline, NS between treatments, ANOVA). By the end of the fifth month there was a 40.7% reduction in hyperkeratosis in the calcipotriol group (from 2.1 +/- 0.1 mm to 1.2 +/- 0.1 mm) and 51.9% in the betamethasone dipropionate and salicylic acid group (from 2.7 +/- 0.1 mm to 1.3 +/- 0.1 mm; P < 0.0001 from baseline, NS between treatments, ANOVA). The results of the study show that calcipotriol is as effective as a combination of a topical steroid with salicylic acid in the treatment of nail psoriasis and represents a safe alternative in the topical treatment of nail psoriasis.

Adult↗
PubMed1997

Nail lichen striatus: clinical features and long-term follow-up of five patients.

BACKGROUND: Nail involvement in lichen striatus (LS) is uncommon and has always been reported in association with typical skin lesions. OBJECTIVE: We attempted to characterize the clinical and pathologic features and the long-term prognosis of nail LS. METHODS: Five cases of LS of the nail including three cases with exclusive nail involvement were evaluated and the literature reviewed. RESULTS: Biopsy specimens showed a moderately dense bandlike lymphohistiocytic infiltrate affecting the proximal nailfold, the nail bed, and the nail matrix dermis. Exocytosis with slight spongiosis, focal hypergranulosis, and dyskeratotic cells were detectable in the nail matrix epithelium. Spontaneous regression of the onychodystrophy occurred after 4 to 12 months from the time of diagnosis (mean, 8.4 months). CONCLUSION: Nail LS is not necessarily associated with skin lesions but can also be an isolated finding. The diagnosis of nail LS should be strongly suspected when a child or a young patient presents with lichen planus-like nail abnormalities localized to the lateral or medial portion of a single nail.

Adolescent↗
PubMed1996

Nail matrix nevi: a clinical and histopathologic study of twenty-two patients.

BACKGROUND: Because most dermatologists do not regularly perform biopsies of longitudinal melanonychia, even when the pigmentation presents as a single band, the true prevalence of nail matrix nevi is unknown. OBJECTIVE: Our purpose was to determine the prevalence of nail matrix nevi in white patients with longitudinal melanonychia involving a single digit and to determine whether longitudinal melanonychia caused by a nail matrix nevus can be clinically distinguished from longitudinal melanonychia from other causes. METHODS: From January 1989 to December 1994 we performed a nail biopsy on 100 of 128 consecutive white patients who had a single band of "idiopathic" longitudinal melanonychia. RESULTS: A nail matrix nevus was detected in 22 patients. A junctional nevus was found in 19 specimens and a compound nevus in three specimens. CONCLUSION: Nail matrix nevi in Caucasian patients are uncommon but not exceptional. The number of nevi presenting with longitudinal melanonychia exceeded that of melanoma. The diagnosis of nail matrix nevi is impossible clinically and always requires histopathologic study. The pathologic features of nail matrix nevi are similar to those of skin nevi except for their architectural pattern, which reflects the peculiar anatomy of the nail unit.

Adolescent↗
PubMed1994

Characterization of cultured nail matrix cells.

BACKGROUND: Cultures of epidermal cells are commonly used to study skin biology and differentiation. Recently a method to culture nail matrix cells has been established. OBJECTIVE: We report the biologic characteristics of nail matrix cells in vitro compared with those of epidermal keratinocytes. METHODS: Human nail matrix cells were isolated and cultured in defined medium. Electron-microscopic examination, growth rate, integrin expression and keratin synthesis pattern were evaluated. In addition, the cells were cultured in serum-containing medium. RESULTS: Nail matrix cells appear to be larger than human epidermal keratinocytes and, at the ultrastructural level, they contain a higher euchromatin/heterochromatin ratio and a lower nucleus/cytoplasm ratio and have a higher growth rate. The synthesis of "hard" keratins was detected at all calcium concentrations. Immunofluorescence analyses showed the expression of alpha 2, alpha 3, and alpha 6 integrin subunits. When cultured in serum-containing medium, nail matrix cells produced an outgrowth of epithelium and a spontaneous migration phenomenon associated with a tendency to stratify in a semilunar area that resembles the architecture of the nail matrix. The pluristratified epithelium showed characteristic markers of nail differentiation. CONCLUSION: Culture of nail matrix cells may represent a useful model to study the biologic properties of nail structure, alterations in some nail diseases and the effects of drugs.

Cell Division↗
PubMed1994

Characterization of nail matrix melanocytes with anti-PEP1, anti-PEP8, TMH-1, and HMB-45 antibodies.

BACKGROUND: The normal nail matrix contains quiescent melanocytes with a peculiar arrangement and behavior. OBJECTIVE: Our purpose was to identify nail matrix melanocytes with antibodies that recognize melanocytic cells in tissue sections. METHODS: We used the polyclonal antibodies anti-PEP1 and anti-PEP8 and the monoclonal antibody TMH-1, which recognize melanocytic enzymes, and the monoclonal antibody HMB-45, which reacts with melanoma cells and fetal melanocytes, but not with normal adult melanocytes. Nail matrix specimens were obtained from longitudinal specimens of eight white patients with ingrown toenails. Specimens from normal adult forearm skin were used as controls. RESULTS: All nail specimens gave similar results. Dendritic melanocytes were more numerous in the distal than in the proximal nail matrix. They were not restricted to the basal layer, but were also found in the suprabasal layers of the nail matrix epithelium. Melanocytes were seen both a single dendritic cells among the nail matrix keratinocytes and as small clusters that appeared irregularly distributed along the length of the nail matrix. Each cluster usually consisted of three to four cells. CONCLUSION: Even if normally quiescent, nail matrix melanocytes possess the key enzymes responsible for the formation of melanin. The suprabasal location of nail matrix melanocytes may be a consequence of the distribution of adhesion molecules in the nail epithelium. In fact, in the nail matrix alpha 2, alpha 3, and beta 1 integrins are not only expressed on the basal, but also on the fourth to fifth suprabasal layers, with suprabasal expression gradually decreasing from distal to proximal matrix. The behavior of nail matrix keratinocytes may cause the peculiar arrangement and behavior of nail matrix melanocytes.

Antibodies, Monoclonal↗
PubMed1994

Nail matrix hypergranulosis.

Nail pathology shares some common features with skin pathology, but it also has its own peculiar aspects. The anatomical and physiological characteristics of the nail unit probably play a major role in determining these pathological differences. Although the presence of keratohyaline granules is a normal feature of the skin, there is no granular layer in the normal nail matrix. As a consequence, nail matrix hypergranulosis should be considered a separate entity from skin hypergranulosis. In our review of 150 longitudinal nail biopsy specimens, keratohyaline granules were seen in the nail matrix of 24 cases of lichen planus, 29 cases of spongiotic trachyonychia, 10 cases of psoriasis, and three cases of Hallopeau acrodermatitis. In all cases, the presence of keratohyaline granules was associated with the absence of the normal keratogenous zone. Similar nail matrix features were detectable in three cases of malignant melanoma, two cases of primary systemic amyloidosis, and one case of histiocytoid hemangioma compressing the nail matrix. Our data suggest that inflammatory and compressive insults to the nail matrix cause both disappearance of the keratogenous zone and matrix keratinization with the formation of keratohyaline granules. Skin hypergranulosis reflects a hyperplasia of a normal skin component. In the nail matrix, however, hypergranulosis represents the appearance of structures not normally present. Nail matrix hypergranulosis should be considered a pattern of nail matrix reaction to different inflammatory insults. It is therefore more analogous to epidermal parakeratosis than to epidermal hypergranulosis.

Acrodermatitis↗
PubMed1994

Expression of integrins in human nail matrix.

The aim of this study was to characterize cell-cell and cell-matrix interaction by evaluating the expression of different integrins in the nail matrix. Nail biopsies were obtained from two cadaver fingers, and eight patients with ingrowing toenails. Frozen sections were stained by indirect immunofluorescence using anti-alpha 1, anti-alpha 2, anti-alpha 3, anti-alpha 4, anti-alpha 5, anti-alpha 6, anti-alpha v, anti-beta 1, anti-beta 4 and anti-ICAM-1 monoclonal antibodies. Biopsies from normal human foreskin were evaluated as controls. alpha 1, alpha 4 and alpha 5 subunits were absent from both nail matrix and normal human skin. alpha 2, alpha 3 and beta 1 subunits were expressed in the basal and suprabasal layers of nail matrix, but only in the basal layer of skin epidermis. alpha 6 and beta 4 subunits were strongly expressed in the basement membrane zone and in the basal layer of both nail matrix and epidermis. The alpha v subunit was expressed in the basal layer of nail matrix. ICAM-1 was not expressed in nail matrix epidermis. Our findings show that despite the distinctive features of the nail apparatus, compared with the epidermis, the pattern of integrin expression is similar, although some differences in the distribution of alpha 2, alpha 3 and beta 1 subunits are detectable. These are probably related to the peculiar differentiation and keratinization of the nail.

Basement Membrane↗
PubMed1994

Alopecia areata. A pathological study of nonresponder patients.

Fourteen patients, four male and 10 female and ranging in age from 11 to 57 years, affected by longstanding alopecia areata that had not responded to sensitizing treatments, were submitted to scalp biopsy. Five patients had alopecia totalis and nine had alopecia universalis. The biopsy was performed on a scalp area that had been bald for > or = 1 year. We distinguished four distinct pathological patterns, which we termed "established bald patch," "early regrowth," "telogen," and "scarring," in four, seven, one, and two patients, respectively. Our study shows that, from a pathological point of view, nonresponder patients constitute a heterogeneous population. The pathological study of the scalp helps predict therapeutic failure only in the small proportion of nonresponder patients that shows a scarring pathological pattern.

Adolescent↗
PubMed1993

Lichen planus limited to the nails in childhood: case report and literature review.

Although nail abnormalities have been reported to occur in 1% to 10% of patients with lichen planus, in children with lichen planus they are rarely mentioned in the literature. An 11-year-old boy had a two-month history of nail dystrophy affecting all the fingernails and the great toenails. The nail plates showed longitudinal ridging and thinning as well as onycholysis and distal splitting. There were no cutaneous or mucous membrane abnormalities. A nail biopsy specimen showed hyperkeratosis, hypergranulosis, and acanthosis in the ventral portion of the proximal nail fold and in the nail matrix. A band-like lymphocytic infiltrate was present in the superficial dermis, and the basal layer showed vacuolar alterations. A diagnosis of lichen planus was made. Treatment was intramuscular triamcinolone 20 mg once a month for six months. Since 1969 only 13 proved pediatric cases of lichen planus limited to the nails have been reported, including two children with 20-nail dystrophy and four with idiopathic atrophy of the nails.

Biopsy↗
PubMed1993

Nail changes of punctate keratoderma: a clinical and pathological study of two patients.

The pathological study of the nail changes of 2 patients affected by punctate keratoderma is described. Both patients presented nail abnormalities that were clinically suggestive of a nail psoriasis. Subungual hyperkeratosis was a prominent feature but onycholysis, splinter haemorrhages and pitting were also present. The pathology of the nail bed revealed sharply limited columns of hyperkeratosis associated with hypergranulosis and depression of the underlying nail bed epidermis. Etretinate therapy produced a significant improvement in the palmoplantar keratoderma, but it was of no apparent value in treating nail keratoderma.

Adult↗