Comparison of histopathological features and prognosis of classical and follicular variant papillary thyroid carcinoma.

PURPOSE: To compare the histopathological features and the outcomes of the follicular variant and classical variant of papillary thyroid carcinoma. MATERIAL AND THE METHODS: Demographic data, histopathological features (tumor size, thyroid capsule invasion, extrathyroidal extension, vascular invasion and multicentricity), lymph node metastasis, local recurrence, distant metastasis and mortality during the follow-up of 258 C-PTC and 153 FVPTC patients who underwent total thyroidectomy were compared. The dynamic risk assessment system was used to refine postoperative risk estimates based on the assessment of response to initial treatment. RESULTS: The demographic data showed no significant difference between the two groups. The mean tumor size showed no significant difference between the two groups. The rate of thyroid capsule invasion, extrathyroidal extension, and lymph node metastasis was significantly higher in C-PTC than in FVPTC group, whereas multicentricity and bilobar involvement were significantly higher in FVPTC group than in C-PTC group. Central lymph node metastasis was significantly more frequent in patients with C-PTC than in those with FVPTC (p < 0.0001). Local recurrence was found in 22 (5.3 %) patients overall and was significantly more common in C-PTC group than in FVPTC group. In patients ≥45 years, the local recurrence rate was significantly higher in patients with CPTC than in those with FVPTC. The local recurrence rate in patients <45 years was not significantly different between the two groups of patients. The multicentricity rate was significantly higher in the FVPTC group for both age groups. Dynamic risk assessment showed that the rate of intermediate- and high-risk groups showed no significant difference between C-PTC and FVPTC patients but the rate of low risk patients was higher in FVPTC group than in C-PTC group (p = 0.04). The recurrence rate in low-risk group was found higher in C-PTC compared to FVPTC patients (4.7 vs. 0.7 %, p = 0.04, respectively). The recurrence rate showed no significant difference in both intermediate- and high-risk groups in C-PTC and FVPTC patients. During the follow-up, the rate of distant metastasis and disease-specific mortality was not significantly different between the two groups (p = 0.25). CONCLUSION: FVPTC is a common subtype of PTC and has a higher rate of multicentricity with bilobar involvement. Although aggressive histopathologic features, such as thyroid capsule invasion, extrathyroidal extension, and lymph node metastasis, are significantly more frequent in CPTC than in FVPTC, the long-term outcome is similar in both subtypes after appropriate initial surgery and postoperative RAI ablation treatment.

DEET-loaded solid lipid particles for skin delivery: in vitro release and skin permeation characteristics in different vehicles.

DEET (N,N-diethyl m-toluamide) is a lipophilic compound which has a common use as an insect repellent and causes not only skin irritation but also systemic side effects at high concentrations in long-term skin application. In this study, DEET is incorporated into solid lipid particles, a colloidal drug delivery system, in order to reduce the percutaneous permeation and avoid toxic effects and also maintain drug effectiveness on the skin surface for a long duration of insect repellence. Solid lipid particles were prepared based on emulsion systems at different concentrations and after the characterization studies, the formulation with 20% lipid phase and 1:1 drug:lipid ratio was carried to in vitro release and skin permeation studies. Solid lipid particles with DEET were compared to free DEET using cream and hydrophilic gel vehicles. Results showed that incorporation of DEET into solid lipid particles reduced the release rate and skin permeation of DEET. Imaging studies using scanning electron microscopy showed that there were still solid lipid particles on skin surface after 2 h indicating that DEET could be present for a longer time on the application site.

Solid lipid nanoparticles (SLN) for topical drug delivery: incorporation of the lipophilic drugs N,N-diethyl-m-toluamide and vitamin K.

Solid lipid nanoparticles (SLN) for topical delivery were prepared by high pressure homogenization using solid lipids. The lipophilic agents DEET (N,N-diethyl-m-toluamide) and vitamin K were used as model drugs. These topical agents were incorporated into SLN which were characterized. Differential scanning calorimetry studies were performed in order to detect probable interactions in the SLN dispersions. Physical stability of SLN in aqueous dispersions and the effect of drug incorporation into SLN were investigated by photon correlation spectroscopy and zeta potential measurements. Characterization and short-term stability studies showedthat DEET and vitamin K are good candidates for topical SLN formulations.

Progress in forensic anthropology: the 20th century.

Anthropological contribution to forensic sciences has been multifaceted and the progress has been remarkable in the last quarter of this century. The field has brought together scientists from all around the world. The purpose of this paper is to present a special issue on forensic anthropological research. Some of the papers cover age estimation from the ankle and knee epiphyses (India), basioccipital synchondrosis (also India), sternal end rib metamorphosis in Turks, and histomorphometry of the Japanese. Sex determination from the South African cranium and Mongoloid humerus are the subject of two papers. Factors of individualization include a comparison of photographic images using neural network, bone trabecular radiography, determination of handedness from the humerus, time since death using 210Po to 210Pb ratio, and changes in the mineral content of bone after burial. From the papers in this special issue it can be concluded that there will be integration of many areas of forensic sciences to deal with anthropological issues in the 21st century. Estimation of time since death will be based on new and more precise techniques. Further research is needed to develop population specific osteological standards for populations of Africa, central and southeast Asia and Pacific region. In addition, there will be an increased interest in the study of living people.