Histologic changes in the eustachian tube mucosa of rats after short-term exposure to cigarette smoke.

OBJECTIVE AND BACKGROUND: It is generally accepted that cigarette smoke is a major risk factor for middle ear disease. However, the literature is void of articles addressing the direct relationship between cigarette smoke exposure and middle ear disease. Furthermore, there are many conflicting opinions concerning the role of cigarette smoke in the pathogenesis of middle ear disease. The purpose of this study was to evaluate the effects of cigarette smoke on the Eustachian tube mucosa. MATERIALS AND METHODS: Thirty healthy 150 to 230 g Sprague Dawley rats with normal middle ears were used. The animals were divided into six groups of five. Five experimental groups (N=5 each) were exposed to a domestic cigarette (This, tar 7.0 mg, nicotine 0.75 mg) every 30 minutes (total 2.5 hours, 5 cigarettes total) on a daily basis in a smoking chamber for 1, 2, 4, 6, or 8 weeks. A control group (N=5) was placed in the same chamber without exposure to cigarette smoke. After exposure, the animals were sacrificed and cross sections of the Eustachian tubes were prepared. Histologic changes of the Eustachian tube mucosa were observed through light and electron microscopes. RESULTS: Loss of cilia, goblet cell depletion, and squamous metaplasia of the Eustachian tube mucosa were observed following exposure to smoke. The one- and two-week exposure groups demonstrated the greatest decrease in goblet cell counts. The eight-week exposure group showed recovery from this decrease. Squamous metaplasia was observed in all experimental groups and was most prominent in the eight-week exposure group. CONCLUSION: These findings suggest that cigarette smoke directly affects Eustachian tube mucosa in the early stages of exposure. Some of the mucosal changes, however, were reversed during the latter stages of exposure. A mechanism different from that which occurs in the nasal cavity and trachea may be activated in the Eustachian tube after exposure to passive smoke. The protective function of the Eustachian tube may play some role in this mechanism.     

The "High-Riding" superior pericardial recess: CT findings

OBJECTIVE. We recently observed patients in whom the superior pericardial recess extended cephalad ("high-riding") into the right paratracheal region. In these patients, differentiation from mediastinal lymphadenopathy or mass was difficult. The purpose of this study was to assess the prevalence and CT features of the high-riding superior pericardial recess. CONCLUSION. Narrow-collimation CT with multiplanar reformations was useful for confidently diagnosing a high-riding superior pericardial recess and for distinguishing it from pathologic lesions.     

Vascular endothelial growth factor gene polymorphisms and risk of primary lung cancer.

Angiogenesis is an essential process in the development, growth, and metastasis of malignant tumors including lung cancer. DNA sequence variations in the vascular endothelial growth factor (VEGF) gene may lead to altered VEGF production and/or activity, thereby causing interindividual differences in the susceptibility to lung cancer via their actions on the pathways of tumor angiogenesis. To test this hypothesis, we investigated the potential association between three VEGF polymorphisms (-460T > C, +405C > G, and 936C > T)/haplotypes and the risk of lung cancer in a Korean population. VEGF genotypes were determined in 432 lung cancer patients and 432 healthy controls that were frequency matched for age and sex. VEGF haplotypes were predicted using Bayesian algorithm in the phase program. Compared with the combined +405 CC and CG genotype, the +405 GG genotype found associated with a significantly decreased risk of small cell carcinoma [SCC; adjusted odds ratio (OR), 0.36; 95% confidence interval (95% CI), 0.17-0.78]. The 936 CT genotype and the combined 936 CT and TT genotype were also associated with a significantly decreased risk of SCC compared with the 936 CC genotype (adjusted OR, 0.47; 95% CI, 0.26-0.85 and adjusted OR, 0.44; 95% CI, 0.24-0.80, respectively). Haplotype CGT was associated with a significantly decreased risk of SCC (adjusted OR, 0.39; 95% CI, 0.18-0.87), whereas haplotype TCC conferred a significantly increased risk of SCC (adjusted OR, 1.63; 95% CI, 1.14-2.33). None of the VEGF polymorphisms studied significantly influenced the susceptibility to lung cancer except SCC. However, haplotypes TCT and TGT were significantly associated with the risk of overall lung cancer, respectively (adjusted OR, 0.38; 95% CI, 0.25-0.60 and adjusted OR, 3.94; 95% CI, 2.00-7.76, respectively). These effects of haplotypes TCT and TGT on lung cancer risk were observed in three major histologic types of lung cancer. These results suggest that the VEGF gene may be contribute to an inherited predisposition to lung cancer.     

Effect of safflower seeds supplementation on stimulation of the proliferation, differentiation and mineralization of osteoblastic MC3T3-E1 cells

Anti-bone resorption properties of the Korean herbal formulation, Gami-Honghwain (HJ), which comprises Carthamus tinctorius L. seed and hominis placenta, were investigated. We demonstrate that the production of PGE2 is inhibited by 20-100 microg/ml HJ in nontransformed osteoblastic cells (MC3T3-E1 cells), indicating that HJ inhibits PGE2 production. The effect of HJ on the proliferation and osteoblastic differentiation in MC3T3-E1 was also studied. HJ dose-dependently increased DNA synthesis (significant at 20-100 microg/ml), and increased alkaline phosphatase (ALP) and prolyl hydroxylase activities of MC3T3-E1 cells (20-100 microg/ml), while anti-estrogen tamoxifen eliminated the stimulation of proliferation and ALP activity of MC3T3-E1 which was induced by HJ. These results indicate that HJ directly stimulates cell proliferation and differentiation of osteoblasts. Also, when we assessed the effects of HJ on osteoblastic differentiation in MC3T3-E1, HJ enhanced ALP activity and mineralization in a dose- and time-dependent fashion. This stimulatory effect of the HJ was observed at relatively low doses (significant at 20-100 microg/ml and maximal at 100 microg/ml). Northern blot analysis showed that the HJ (60 microg/ml) increased in bone morphogenetic protein-2 as well as ALP mRNA concentrations in MC3T3-E1 cells. HJ (100 microg/ml) slightly increased in type I collagen mRNA abundance throughout the culture period, whereas it markedly inhibited the gene expression of collagenase-1 between days 15 and 20 of culture. These results indicate that HJ has anabolic effect on bone through the promotion of osteoblastic differentiation, suggesting that it could be used for the treatment of common metabolic bone diseases.     

A high yield of fetal nucleated red blood cells isolated using optimal osmolality and a double-density gradient system

OBJECTIVES: To increase the yield of fetal nucleated red blood cells (NRBCs) from maternal blood using a discontinuous Percoll gradient and to determine the effects of osmolality on NRBC yield. METHODS: Fetal NRBCs were isolated from combined umbilical cord blood and adult female blood, or from maternal blood using single or double Percoll gradients with different osmolalities. Magnetic activated cell sorting was used to enrich isolated NRBCs, and morphological differentiation was performed with Kleihauer-Betke stain. We also isolated fetal NRBCs from 25 10 mL samples of maternal blood and determined fetal sex by fluorescence in situ hybridization (FISH), using X-Y probes. RESULTS: For single-density Percoll columns, the greatest number of NRBCs was isolated using 280 mOsm/kg H(2)O with 1.077 g/mL Percoll and 520 mOsm/kg H(2)O with 1.119 g/mL Percoll. Significantly more fetal NRBCs were isolated with double Percoll density gradients than with double-Histopaque gradients (p = 0.043). FISH analysis on NRBC in 25 cases correctly identified 15 male and 9 female euploid fetuses and one Trisomy 21 fetus. CONCLUSION: The NRBC enrichment method we present requires less maternal blood and yields more NRBCs compared to previous methods.     

Fabrication of Large-Area Mullite–Cordierite Composite Substrates for Semiconductor Probe Cards and Enhancement of Their Reliability

This work aims to fabricate a large-area ceramic substrate for the application of probe cards. Mullite (M) and cordierite (C), which both have a low thermal expansion coefficient, excellent resistance to thermal shock, and high durability, were selected as starting powders. The mullite–cordierite composites were produced through different composition ratios of starting powders (M:C = 100:0, M:C = 90:10, M:C = 70:30, M:C = 50:50, M:C = 30:70, and M:C = 0:100). The effects of composition ratio and sintering temperature on the density, porosity, thermal expansion coefficient, and flexural strength of the mullite–cordierite composite pellets were investigated. The results showed that the mullite–cordierite composite pellet containing 70 wt% mullite and 30 wt% cordierite sintered at 1350 °C performed exceptionally well. Based on these findings, a large-area mullite–cordierite composite substrate with a diameter of 320 mm for use in semiconductor probe cards was successfully fabricated. Additionally, the changes in sheet resistance and flexural strength were measured to determine the effect of the environmental tests on the large-area substrate such as damp heat and thermal shock. The results indicated that the mullite–cordierite composite substrate was extremely reliable and durable.