Tumorigenicity of acrylamide and its metabolite glycidamide in the neonatal mouse bioassay

Acrylamide is a high-volume industrial chemical, a component of cigarette smoke, and a product formed in certain foods prepared at high temperatures. Previously, we compared the extent of DNA adduct formation and mutations in B6C3F(1) /Tk mice treated neonatally with acrylamide or glycidamide to obtain information concerning the mechanism of acrylamide genotoxicity. We have now examined the tumorigenicity of acrylamide and glycidamide in mice treated neonatally. Male B6C3F(1) mice were injected intraperitoneally on postnatal days 1, 8 and 15 with 0.0, 0.14 or 0.70 mmol acrylamide or glycidamide per kg body weight per day and the tumorigenicity was assessed after 1 year. Survival in each of the groups was >87%, there were no differences in body weights among the groups, and the only treatment-related neoplasms involved the liver. The incidence of combined hepatocellular adenoma or carcinoma was 3.8% in the control group, 8.3% in the 0.14 mmol acrylamide and glycidamide per kg body weight groups, 4.2% in the 0.70 mmol acrylamide per kg body weight group and 71.4% in the 0.70 mmol glycidamide per kg body weight group. Analysis of the hepatocellular tumors indicated that the increased incidence observed in mice administered 0.70 mmol glycidamide per kg body weight was associated with A → G and A → T mutations at codon 61 of H-ras. These results, combined with our previous data on DNA adduct formation and mutation induction, suggest that the carcinogenicity of acrylamide is dependent on its metabolism to glycidamide, a pathway that is deficient in neonatal mice.     

HIV-Associated facial lipoatrophy: from the advent to current knowledge

The advent of AIDS has brought new challenges to Dermatology. Antiretroviral therapy dramatically changed the morbidity and mortality associated with HIV / AIDS, but contributed to the emergence of other new situations that require adequate approach by the dermatologist. The HIV / AIDS Associated Lipodystrophy Syndrome is multifactorial in origin, but it is strongly associated with the use of antiretroviral drugs. It includes changes in body fat distribution, with or without metabolic changes. The loss of facial fat, called facial lipoatrophy, is one of the most stigmatizing signs of the syndrome. This condition, often revealing of the disease, brought back the stigma of AIDS. It is necessary that the specialists working with patients with HIV / AIDS identify these changes and seek treatment options, amongst which stands out the implant with polymethylmethacrylate, which is available for the treatment of HIV / AIDS facial lipoatrophy in the Brazilian Public Health System.     

Marjolin's ulcer associated with ulceration and chronic osteomyelitis

This report describes a 78-year old male patient with a chronic venous ulcer on his left leg for the past 24 years, complicated by a squamous-cell carcinoma. After staging of the disease, the treatment administered was amputation of the leg above the knee. Marjolin's ulcer consists of the malignant transformation of a chronic ulcerative lesion. It is a relatively rare phenomenon. The malignant tumor most commonly described in the literature is squamous cell carcinoma, followed by basal-cell carcinoma, sarcoma and melanoma. The pathogenesis of Marjolin's ulcer remains to be fully clarified.     

Clinical and Laboratory Features in Acute Generalized Pustular Psoriasis

Background: Acute generalized pustular psoriasis (AGPP) is a rare variant of psoriasis that can be lethal without proper treatment. It can be caused by the withdrawal of corticosteroids and, among its extracutaneous manifestations, liver abnormalities are frequently under-reported or attributed to drugs. Objective: The aim of this study was to assess the clinical and laboratory data, treatment options, and disease outcome in patients with AGPP and to search for significant differences between subgroups of these patients. Study Design: This was a retrospective analysis of the clinical files from inpatients with AGPP observed in our department between 1973 and 2008. Statistical tests were performed at a significance level of 5%. Setting: This was an inpatient, single-center study. Main Outcome Measures: Outcome measures were a previous history of psoriasis, corticosteroid use before admittance, mortality rate, white blood cell count, absolute neutrophil count, and abnormalities in liver enzymes. Results: Atotal of 34 patients fulfilled the inclusion criteria, of whom 61%were men and 65%had a previous history of psoriasis vulgaris. Topical corticosteroids were applied by 50%of patients before admittance. Skin lesions remitted with methotrexate, etretinate, or acitretin treatment in all but two patients who died of sepsis. Abnormalities in liver enzymes were present in 47%of patients. Patients without a previous history of psoriasis had a significantly younger age at the first episode of AGPP. In the comparison between the groups of patients with and without liver abnormalities, a male preponderance and higher leukocyte counts were found in the former, with a positive correlation between the absolute neutrophil count and total bilirubin also being observed. Previous use of retinoids or methotrexate was not associated with these hepatic alterations. Limitations: Limitations of the data were that this was a single-center, retrospective study with a small sample size. Conclusions: Withdrawal of systemic or topical corticosteroids can precipitate or worsen AGPP and these agents should not be used in these patients. Liver abnormalities can be considered an extra-cutaneous manifestation of AGPP. As in other series, no association between the use of drugs and changes in liver tests was found and therefore the deleterious withdrawal of efficient drugs, namely acitretin and methotrexate, should be avoided.     

Ex vivo evaluation of the effectiveness of bleaching agents on the shade alteration of blood-stained teeth

Aim To evaluate ex vivo effectiveness of the three formulations of bleaching materials for intracoronal bleaching of root filled teeth using the walking bleach technique. Methodology Extracted premolar teeth were stained artificially with human blood. After biomechanical preparation, the root canals were filled and a 3‐mm thick intermediate base of zinc phosphate cement was placed at the level of the cementoenamel junction. The teeth were divided into four groups (n = 12): C (control, without bleaching material), A1 (sodium perborate + distilled water), A2 (sodium perborate + 10% carbamide peroxide) and A3 (sodium perborate + 35% carbamide peroxide). The bleaching materials were changed at 7 and 14 days. Evaluation of shade was undertaken with aid of the VITA Easyshade? (ΔE*ab) and was performed after tooth staining and at 7, 14 and 21 days after bleaching, based on the CIELAB system. Data were analysed by anova for repeated measurements, Tukey and Dunnett tests (α = 0.05). Results The Tukey test revealed that group A1 (10.58 ± 4.83 ΔE*ab) was statistically different from the others (A2, 19.57 ± 4.72 ΔE*ab and A3, 17.58 ± 3.33 ΔE*ab), which were not different from each other. At 7 days: A1 was significantly different from A2; at 14 and 21 days: A2 and A3 were significantly better than A1; the Dunnett test revealed that the control group was different from A1, A2 and A3 at all periods (P < 0.05). Conclusion Sodium perborate associated with both 10% and 35% carbamide peroxide was more effective than when associated with distilled water.     

Surgically assisted maxillary expansion in adults: prospective study

The purpose of this research was to carry out a prospective clinical study of patients with transverse maxillary deficiency, orthopaedically expanded after minimum osteotomies of the zygomatic pillars and the median palatine suture, with quantitative assessment of the stability of the transverse dimensions of the maxilla. The distance between the superior canines and the first superior molars was measured six times during the clinical experiment. The desired expansion was achieved by 15 days postoperatively for all patients. After one year of follow-up, clinical measurements showed a relapse rate of 23% in the superior canine area and 18% in the superior first molar area.