Cutaneous angiosarcoma of the distal extremity

A case of childhood cutaneous angiosarcoma is presented to emphasize the importance of accurate histological diagnosis in lymphovascular malformations that behave atypically and to review the natural history, aetiology, and differential diagnosis of this condition. Accepted: 4 April 1997     

Computed tomography appearance of melanoma of nasal cavity

Melanoma of the nasal cavity is a mucosal lesion that is quite rare. It comprises less than 1% of all melanomas and constitutes 4% of primary malignant tumors of the nasal cavity. The computed tomography appearance of this entity is discussed and found to be nonspecific.     

Effectiveness of oral dexamethasone in the treatment of moderate to severe pharyngitis in children

OBJECTIVE: To determine the effectiveness of a single dose of oral dexamethasone in reducing the pain associated with moderate to severe pharyngitis in pediatric patients. DESIGN: Prospective, randomized, double-blind, placebo-controlled clinical trial. SETTING: Large, urban pediatric emergency department between March 2002 and November 2003. PATIENTS: Children aged 5 to 18 years with moderate to severe pharyngitis (odynophagia or dysphagia, moderate to severe pharyngeal erythema or swelling, and a McGrath Facial Affective Scale score of 0.75 or higher [scale 0.0-1.0]). INTERVENTIONS: Study patients were randomly assigned to receive 1 dose of either oral dexamethasone suspension (0.6 mg/kg with a maximum of 10 mg) or placebo of the same volume. All participants were tested for group A beta-hemolytic streptococcal pharyngitis and treated accordingly. Daily telephone follow-up was conducted until complete resolution of sore throat. MAIN OUTCOME MEASURES: Primary outcome variables included hours to initial relief of sore throat and time to the complete resolution of pain. Secondary outcome variables included changes in the McGrath Facial Affective Scale score at 24 and 48 hours, persistence of associated symptoms, use of anti-inflammatory or antipyretic medication, and subsequent use of medical resources for dehydration or pain. RESULTS: A convenience sample of 150 patients was randomized to receive either dexamethasone (n = 75) or placebo (n = 75). Twenty-five patients were lost to follow-up, leaving 125 patients available for data analysis; 57 received dexamethasone and 68 received placebo. Patients who received dexamethasone reported earlier onset of pain relief (9.2 vs 18.2 hours; P<.001), fewer hours to complete resolution of sore throat (30.3 vs 43.8 hours; P = .04), and larger changes in the McGrath Facial Affective Scale score in the first 24 hours (-0.58 vs -0.43; P = .002). Children who tested negative for group A beta-hemolytic streptococci had greater pain relief with dexamethasone compared with placebo (onset of pain relief, 8.7 vs 24 hours; P = .001), less time to complete resolution of sore throat (37.9 vs 70.8 hours; P = .006), and greater changes in the McGrath Facial Affective Scale score in the first 24 hours (-0.50 vs -0.21; P<.001). CONCLUSION: Children with moderate to severe pharyngitis had earlier onset of pain relief and shorter duration of sore throat when given oral dexamethasone.     

Catalase restores the altered mRNA expression of collagen and matrix metalloproteinases by dermal fibroblasts exposed to reactive oxygen species

We investigated the effects of reactive oxygen species (ROS) on mRNA expression of proalpha1(I) collagen, proalpha1(III) collagen, matrix metalloproteinases-1 (MMP-1), 72 kDa type IV collagenase (MMP-2), and tissue inhibitor of metalloproteinase (TIMP-1) by normal human dermal fibroblasts in a novel three-dimensional culture. Fibroblasts exposed to ROS generated by the hypoxanthine-xanthine oxidase system revealed an increased mRNA expression of MMP-1 and MMP-2 with a maximum at 48 h and 72 h after exposure. A slight increase in the mRNA level of tissue inhibitor of metalloproteinase (TIMP-1) was observed. Increased protein level of MMP-1 and its collagenolytic activity and gelatinolytic activity of MMP-2 was comfirmed as well. In contrast, a time-dependent suppression of both proalpha1(I) and proalpha1(III) collagen mRNA expression was observed 12 h after ROS treatment with a maximum at 48 h and 72 h. Addition of catalase totally abrogated the ROS-induced alteration of these genes. Superoxide dismutase (SOD) abrogated only the increased mRNA expression of MMP-2. These results indicated that ROS mediates the induction of collagenases as well as the suppression of collagen synthesis by dermal fibroblasts in vitro. The biological alterations in collagen metabolism triggered by ROS may be responsible for the development of certain diseases or pathological changes such as photoaged human skin.     

Micro‐computed tomography assessment of root dentin around fluoride‐releasing restorations after demineralization/remineralization

Using micro‐computed tomography (micro‐CT), this study assessed the inhibitory effect of three different types of restorations on root‐caries formation under a cariogenic challenge. Bovine‐root dentin blocks with a cylindrical cavity were divided into three restoration groups: a fluoride‐free self‐etch adhesive and a resin composite (SE‐ES); a self‐etch adhesive and a resin composite with multi‐ion release (FL‐BF); and a glass ionomer cement (Fuji‐VII). After the restorative procedures, the specimens were stored in artificial saliva for 1 d, then subjected to a demineralization solution for 4 d and a remineralization solution for 28 d. Mineral density and mean mineral loss of dentin around the restorations were measured using micro‐CT. The mean mineral loss values of dentin around the restorations were highest among SE‐ES restorations and lowest among Fuji‐VII restorations. Fuji‐VII showed the highest mineral density and the lowest mineral loss after 28 d of remineralization. The observations made by scanning electron microscopy demonstrated that Fuji‐VII created the smallest outer lesion followed by FL‐BF and SE‐ES. Fuji‐VII has a larger inhibitory effect on root caries around the restorations and enhances remineralization more effectively than either FL‐BF or SE‐ES. Multi‐ion and fluoride release from the restorative materials may be beneficial for inhibition of root‐dentin caries around the restorations.     

Successful Treatment of Focal Segmental Glomerulosclerosis in Association with Mantle Cell Lymphoma

We have examined the role of reactive oxygen metabolites (ROM) in gentamicin nephrotoxicity and in glycerol-induced acute renal failure, a model for myoglobinuric acute renal failure. Several agents which affect mitochondrial respiration have been shown to enhance the generation of hydrogen peroxide. Based on gentamicin s ability to alter mitochondrial respiration both in vitro and in vivo we postulated that gentamicin may enhance the generation of ROM by renal com'cal mitochondria. Gentamicin, in a dose-dependent farhion, enhanced hydrogen peroxide production by rat renal cortical mitochondria as measured by the decrease in scopoletin jluorescence. At the highest concentration of gentamicin tested (4.0 mM), the rate of hydrogen peroxide generation w s markedly increased from 0. I7 f 0.02 to 6.21 f 0.67 nmol/mg/m*n. We next demonstrated that hydroxyl radical scavengers and an iron chelator provide a marked functional and histological protection in gentamicin-induced acute renal failure in rats. Hydroxyl radical scavengers and the iron chelator deferoxamine also protected renal function in glycerol-injected rats, a model for acute renal failure due to muscle injury. Although these data suggest that ROM may be important mediators of toxic renal injury, in vivo generation of ROM by kidney in normal and pathological states has not been previously examined. Aminotriazole (An irreversibly inactivates catalase only in the presence of hydrogen peroxide and previous studies have shown that AT-medated inhibition of catalase in a sensitive measure of in vivo changes in the hydrogen peroxide generation. Using this method, we have demonstrated the in vivo generation of hydrogen peroxide under normal conditions and enhanced generation of hydrogen peroxide in rats treated with gentamicin or glycerol. Finally, in in vitro studies we have shown that iron and intracellular calcium play a critical role in hydrogen peroxide-mediated cytotoxicity to LLC-PK, cells, a renal tubular epithelial cell line. Taken together our data provide evidence for a role of ROM in gentamicin and glycerol-induced acute renal failure and provide evidence for the role of iron and calcium in oxidant injury to renal tubular epithelial cells.