Percutaneous penetration and genotoxicity of 4,4'-methylenedianiline through rat and human skin in vitro

4,4'-Methylenedianiline (MDA) is a primary aromatic amine used in the plastics industry and is classified by the International Agency for Research on Cancer as an animal carcinogen and possible human carcinogen. In order to estimate human exposure it is useful to determine percutaneous penetration. Previous studies have suggested that both rat and human skin were permeable to MDA, with greater penetration being seen through human skin. In this study no significant difference was seen between the percutaneous penetration of MDA through human or rat skin for three different treatment levels: 0.01, 0.1 and 1mg per skin membrane (0.32 cm(2)). The apparent dermal flux was calculated as 0.7 +/- 0.3 and 10.1 +/- 2.0 microg/cm(2)/h for the 0.01 and 0.1mg treatments, respectively. The permeability constant K(p) was estimated at 1.8 x 10(-3) cm/h and the lag time at 3.5 +/- 0.5 h. MDA absorbed into the skin was found to be bioavailable. Experiments also showed that after application of 0.1mg MDA, 4% penetrated through latex and nitrile gloves, respectively. The potential genotoxicity of MDA in human skin was assessed by DNA (32)P-postlabelling; levels of DNA adducts were detected, following the treatment and penetration of 1mg MDA.     

Uranotaenia dibrugarhensis, a new species in subgenus Pseudoficalbia from Assam, India

The adult female, adult male, pupa, and larva of Uranotaenia (Pseudoficalbia) dibrugarhensis, new species, are described from the Dibrugarh District of Assam State, India.     

Diagnosis of pancreatic cancer using serum proteomic profiling

In the United States, mortality rates from pancreatic cancer (PCa) have not changed significantly over the past 50 years. This is due, in part, to the lack of early detection methods for this particularly aggressive form of cancer. The objective of this study was to use high-throughput protein profiling technology to identify biomarkers in the serum proteome for the early detection of resectable PCa. Using surface-enhanced laser desorption/ionization mass spectrometry, protein profiles were generated from sera of 49 PCa patients and 54 unaffected individuals after fractionation on an anion exchange resin. The samples were randomly divided into a training set (69 samples) and test set (34 samples), and two multivariate analysis procedures, classification and regression tree and logistic regression, were used to develop classification models from these spectral data that could distinguish PCa from control serum samples. In the test set, both models correctly classified all of the PCa patient serum samples (100% sensitivity). Using the decision tree algorithm, a specificity of 93.5% was obtained, whereas the logistic regression model produced a specificity of 100%. These results suggest that high-throughput proteomics profiling has the capacity to provide new biomarkers for the early detection and diagnosis of PCa.     

Nodal metastasis in major salivary gland cancer: predictive factors and effects on survival

OBJECTIVES: To determine how regional nodal metastasis affects survival in patients with major salivary gland malignancy and to identify clinical predictors for nodal disease. METHODS: Major salivary gland cancer cases with nodal sampling were identified from the Surveillance, Epidemiology, and End Results cancer database for 1988 through 1998. Kaplan-Meier survival analysis was conducted to compare patients with and without histopathologic evidence of nodal disease. Multivariate logistic regression analysis was used to determine the influence of clinical predictors on the presence of regional nodal disease. RESULTS: A total of 1268 patients with major salivary gland malignancy and regional node sampling were identified. Mean age at diagnosis was 58.3 years, with a male-female ratio of 1:4. Mean tumor size was 3.0 cm. Overall mean survival time was 83 months (95% confidence interval, 80-87 months). Patients with no evidence of nodal cancer had significantly improved survival over patients with any pathologically positive nodes (mean survival time, 100 months vs 59 months, respectively; P<.001). Patient age, tumor histopathologic type, facial nerve involvement, extraglandular involvement, tumor grade, and tumor size were significant clinical predictors of nodal disease. Facial nerve involvement, tumor grade, and squamous cell carcinoma subtype exhibited the highest increased odds ratios for nodal metastasis. CONCLUSIONS: Nodal disease significantly decreases survival in patients with major salivary gland malignancy. Tumor histopathologic type, facial nerve involvement, extraglandular tumor extension, and tumor grade are the most important predictors of nodal disease.     

Bacterial colonization of nasal steroid inhalers in chronic rhinosinusitis

BACKGROUND: The aim of this study was to determine if nasal steroid inhalers harbor bacteria. METHODS: Nasal steroid inhalers were randomly selected from an adult patient population with chronic rhinosinusitis. Swab cultures of the tip of the nasal inhaler were obtained and submitted for microbiological analysis. Contemporaneous control cultures were obtained from freshly opened nasal steroid inhalers. Comparisons were conducted between bacterial recovery rates and types of organisms recovered from the patient and control groups. RESULTS: Among 31 nasal inhalers in use, 14 inhalers (45%) were found to harbor bacteria. The most common organisms were coagulase negative Staphylococci (11 inhalers) followed by oral flora (2 inhalers) and bacillus species (1 inhaler). None of the 10 control cultures were found to harbor bacteria. Nasal steroid inhalers in use were more likely to have bacterial colonization than new inhalers (p = 0.008, chi-square). CONCLUSIONS: Nasal steroid inhalers may harbor pathogenic bacteria. Therefore, they may serve as a vehicle for subsequent reinfection.     

Patterns of swallowing failure following medialization in unilateral vocal fold immobility

OBJECTIVE: To quantify the incidence of penetration and aspiration following medialization for unilateral vocal cord immobility (UVCI) and determine patterns of failure. STUDY DESIGN: Blinded analysis consecutive case series. METHODS: Prospective blinded analysis of videofluoroscopic swallowing studies of patients who had received a medialization procedure was conducted, determining the incidence of penetration and aspiration by using the Penetration-Aspiration Scale. Pharyngeal transport measures were also assessed. Associations between clinical factors and penetration-aspiration were statistically determined. RESULTS: Sixty-seven videofluoroscopic swallowing studies were reviewed in patients (mean age, 63.3 y) who had undergone vocal fold medialization (14 laryngoplasties and 53 vocal cord injections) for UVCI. Unilateral vocal cord immobility was left-sided in 56 patients (83.6%), and 50 patients (74.6%) had a postsurgical etiologic factor for their immobility. Thirty (44.8%) and 16 (23.9%) patients demonstrated penetration and aspiration, respectively. Penetration most often occurred during the swallow, but aspiration was equally likely to occur during or after the swallow. No differences in the incidence of penetration or aspiration were noted according to the side of vocal fold paralysis ( P=.20, chi test) or etiologic factor ( P=.69). Further analysis found that swallow factors significantly associated with penetration and aspiration were swallow delay ( P=.001, Wilcoxon ranked pairs test) and reduced laryngeal elevation ( P=.001), as well as bolus residues in the valleculae (P =.002), piriform sinus ( P=.001), or posterior pharynx (P =.008). CONCLUSIONS: Many patients demonstrate significant radiographic aspiration even after medialization procedures for UVCI. Although glottal incompetence is a known risk factor for aspiration, other factors including pharyngeal bolus transport are important in determining an effective swallow in UVCI.     

Comparison of computer-assisted brush biopsy results with follow up scalpel biopsy and histology

Oral brush biopsy results were compared with scalpel biopsy and histology to determine the positive predictive value of an abnormal brush biopsy finding. Of 243 patients with abnormal brush biopsies, 93 proved positive for dysplasia (79) or carcinoma (14) and 150 were negative for either dysplasia or carcinoma. Therefore, the positive predictive value of an abnormal brush biopsy was 38% (93/243). By using the oral brush biopsy, dentists can inform their patients that abnormal findings have a strong positive predictive value for dysplasia or carcinoma and therefore require follow-up confirmation by scalpel biopsy.