Common nail tumors

Nail abnormalities are varied and numerous. They include warts, keratoacanthomas, onychomatricomas, fibrokeratomas, osteochondromas, tumors (ie, glomus, giant cell, Koenen's, and others), and Bowen's disease. Although the gravity of these conditions may vary, prompt diagnosis and treatment is of the utmost importance. This article discusses the most common defects associated with the nail unit and its surrounding tissue, as well as the differential diagnosis and treatment of these conditions.     

Periungual and subungual pyogenic granuloma

Background Nail pyogenic granuloma (PG) is common, often seen as an urgent case, given the recent onset as a bleeding nodule. Nail PGs are due to different causes that act through different pathogenetic mechanisms and may be treated in several ways. Both causes and treatments of nail PG have never been classified. Objectives To classify nail PG according to the pathogenesis, describe the clinical and pathological features and provide guidelines for a correct diagnosis and treatment. Methods A retrospective, observational study was performed reviewing epidemiological and clinical features of 58 cases of PG seen at our Departments in the last 5 years. A review of the literature was also carried out, using PubMed database and dermatological textbooks. Results Nail PG is usually due to the following causes: drugs, local trauma and peripheral nerve injury. Histopathology shows similar features in every type of PG, irrespective of cause and location. Conclusions The localization of nail PG, the number of digits involved and clinical history help to identify the cause. When PG is single, especially if it involves the nail bed, histological examination is necessary to rule out malignant melanoma. Treatment must be chosen according to the underlying cause.     

Bupropion hydroxylation as a selective marker of rat CYP2B1 catalytic activity

Benzyloxyresorufin-O-dealkylation (BROD) is usually used as a marker of cytochrome P450 (P450) 2B1 in rat. However, some reports show that CYP1A2 is also highly implicated. The purpose of the present study was to establish bupropion (BUP) hydroxylation, but not BROD, as a selective in vitro marker of CYP2B1 catalytic activity. IC(50) for BROD and BUP hydroxylation were equivalent (40.8 ± 4.6 and 41.8 ± 3.4 μM, respectively) when using liver microsomes from β-naphthoflavone-pretreated rats in the presence of metyrapone (CYP2B1 inhibitor). When using the same microsomes in the presence of CYP1A1/2-selective inhibitor α-naphthoflavone, we found an IC(50) of 2.5 × 10(-3) ± 0.8 × 10(-3) μM for BROD and >100 μM for BUP hydroxylation. These results suggest that CYP2B1 is similarly involved in both activities, whereas CYP1A2 is involved in BROD activity but not in BUP hydroxylation. BUP hydroxylation was assessed in microsomes from baculovirus-infected insect cells coexpressing NADPH-P450 oxidoreductase, and 14 rat P450s and kinetic parameters (K(m) and V(max)) were determined. BUP hydroxylation was predominantly catalyzed by CYP2B1 (75% of total hydroxybupropion formation), low activity was detected with CYP2E1 and CYP2C11 (10.9 and 8.7% of total hydroxybupropion, respectively), and activity was almost undetectable with the other P450 isoforms at saturating substrate concentrations (2500 μM), thereby validating the use of BUP as a diagnostic in vitro marker of CYP2B1 catalytic activity in rat.     

Plateable cryopreserved human hepatocytes for the assessment of cytochrome P450 inducibility: experimental condition-related variables affecting their response to inducers

Rationale: The aim of the present study was to assess the stability of cryopreserved human hepatocytes over 5 years and to explore experimental condition-related variables such as seeding density, culture matrix and medium, start and duration of treatment that could potentially affect the quality of cultures and their response to cytochrome P450 (CYP) inducers. Results: 63/125 batches of cryopreserved human hepatocytes were plateable after thawing. Of those, 17 batches showed reproducible recovery, viability and plateability (less than 5% intra-batch variability) up to 5 years. When cultured in collagen home-coated 48-well plates at a seeding density allowing 70% confluence, cryopreserved human hepatocytes display activities equivalent to fresh counterparts. Their response to CYP inducers is maximal and equivalent to fresh counterpart for an incubation of 72 h starting at Day 2 or Day 3 after plating when cultured in modified Hepatocyte Maintenance Medium (HMM). The number of cryopreserved human hepatocytes can be further reduced by using a cocktail of CYP substrates for the assessment of their inducibility. Conclusions: Experimental condition-related variables, such as seeding density, culture matrix and medium, start and duration of treatment, affecting the response of plateable thawed cryopreserved human hepatocytes to cytochrome P450 inducers can be reduced by optimizing critical steps of the protocols.     

The University of Western Ontario Pediatric Audiological Monitoring Protocol (UWO PedAMP)

This study proposed and evaluated a guideline for outcome evaluation for infants and children with hearing loss who wear hearing aids. The University of Western Ontario Pediatric Audiological Monitoring Protocol (UWO PedAMP) was developed following a critical review of pediatric outcome evaluation tools and was systematically examined by the Network of Pediatric Audiologists of Canada. It consists of tools to gather clinical process outcomes as well as functional caregiver reports. The UWO PedAMP was administered to a clinical population of infants and children with hearing aids. Sixty-eight children were administered the functional outcome evaluation tools (i.e., caregiver reports) a total of 133 times. Clinical process outcomes of hearing aid verification (e.g., real-ear-to-coupler difference) revealed typical aided audibility (e.g., Speech Intelligibility Index). Results for the LittlEARS(?) questionnaire revealed that typically developing children with hearing loss who wear hearing aids are meeting auditory development milestones. Children with mild to moderate comorbidities displayed typical auditory development during the 1st year of life after which development began to decline. Children with complex factors related to hearing aid use had lower scores on the LittlEARS, but auditory development was in parallel to norms. Parents' Evaluation of Aural/Oral Performance (PEACH) results indicated no age effect on scoring for children above 2 years of age; however, the effect of degree of hearing loss was significant. This work provides clinicians with a systematic, evidence-based outcome evaluation protocol to implement as part of a complete pediatric hearing aid fitting.     

Superficial acral fibromyxoma: clinical and pathological features

Superficial acral fibromyxoma (SAFM) is a recently recognized myxoid tumor that usually occurs on the fingers and toes of middle-aged adults. We report on the typical case of a 50-year-old woman with a SAFM in the right big toenail that had been slowly growing for more than 10 years. To our knowledge, this case is the first reported case for which clinical pictures are available. Histologically, the lesion was non-encapsulated and was composed of stellate and spindle cells, arranged in a myxoid matrix. No atypia or mitotic figures were found. Neoplastic cells showed positive staining for CD34 and negative staining for epithelial membrane antigen (EMA), actin, desmin, keratins, S100 protein, CD99, and HMB45. Differential diagnosis encompasses benign and malignant myxoid and spindle cells tumors such as myxoid neurofibroma, sclerosing perineurioma, superficial angiomyxoma, and several low-grade myxoid sarcomas.