A macrophage-specific synthetic promoter for therapeutic application of adiponectin

Foam cell formation from macrophage is a major cause of atherosclerosis. An efficient macrophage-specific promoter is required for the targeting to macrophages. In this study, we develop a macrophage-specific synthetic promoter for the therapeutic application of adiponectin (APN), an antiatherogenic gene. Synthetic promoter-146 (SP146), registered on the NCBI website (http://www.ncbi.nlm.nih.gov/nuccore/DQ107383), was tested for promoter activities in two non-macrophage cell lines (293 T, HeLa) and a macrophage cell line (RAW264.7, bone marrow-derived macrophages). To enforce macrophage specificity, partial elements of p47(phox) including the PU.1 site with various lengths (-C1, -C2 and -C3) were inserted next to the synthetic promoters. SP146-C1 showed the highest specificity and efficacy in RAW264.7 cells and was selected for development of an APN-carrying macrophage-specific promoter. Green fluorescent protein (GFP)- or APN-expressing lentivirus under SP146-C1 (Lenti-SP-GFP or Lenti-SP-APN, respectively) showed the highest expression efficacy in RAW264.7 cells compared with the non-macrophage cell lines. APN overexpression in RAW264.7 cells successfully inhibited intracellular lipid accumulation, and atherosclerotic lesions and lipid accumulation were significantly reduced by Lenti-SP-APN in ApoE-/- atherosclerosis mice. In conclusion, the synthetic promoter SP146-C1, combined with a p47(phox) promoter element, was successfully developed to target macrophage, and macrophage-specific introduction of APN under SP146-C1 was shown to ameliorate the atherosclerotic pathology.

The effects of statins on the clinical outcomes of Clostridium difficile infection in hospitalised patients

BACKGROUND

An association between exposure to statin drugs and favourable treatment outcomes for various types of infections has been established.

AIM

To determine the clinical characteristics and treatment outcomes of Clostridium difficile infection (CDI) among hospitalised patients taking statin drugs.

METHODS

The medical records were reviewed for consecutive in-patients with CDI confirmed by positive toxin assay (A or B), C. difficile culture, or the presence of pseudomembrane on endoscopy. Treatment success was defined as the resolution of diarrhoea within 6 days of therapy. The primary end points were assessed by average symptom recovery time and treatment response (success or failure).

RESULTS

Among 949 patients, the overall response to metronidazole was 91.9%. The baseline characteristics showed some differences between statin users and statin non-users with respect to mean disease severity score. In the multivariate analysis, successful treatment response was significantly associated with the absence of exposure to proton pump inhibitors (PPIs) (OR = 0.690, 95% CI = 0.513-0.929, P = 0.014) and with exposure to statins (OR = 1.449, 95% CI = 1.015-2.070, P = 0.041). Contrary to the treatment response, univariate and multivariate analyses failed to show that exposure to PPIs or statins affected symptom recovery times. Sixty-day CDI recurrence rates for those patients with statin exposure were significantly lower compared with those patients without statin exposure (3% vs. 7.3%, respectively; RR = 0.393, 95% CI = 0.167-0.926, P = 0.033).

CONCLUSION

Prior statin exposure in patients with C. difficile infection is associated with a successful response to treatment.

Socioeconomic disparities of periodontitis in Koreans based on the KNHANES IV

OBJECTIVES

The aim of this study was to identify the socioeconomic factors associated with the prevalence of periodontitis in Koreans.

METHODS

Cross-sectional data from 12 763 subjects, 15 years old and above, who underwent periodontal examinations were obtained from the Korean National Health and Nutrition Examination Survey IV (2007-209). Multivariate linear and logistic regression analyses were applied to estimate the association between socioeconomic indicators and prevalence of periodontitis.

RESULTS

A significant association was found between increasing age and periodontitis. Participants with higher income were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.78-0.98, and aOR = 0.7 and 95% CI = 0.60-0.80 in the middle and highest quintiles of monthly household income, respectively). In addition, participants living in rural areas were less likely to have periodontitis (aOR = 0.9 and 95% CI = 0.81-0.99), and current smokers were more likely to have periodontitis (aOR = 1.7 and 95% CI = 1.49-1.89). The analysis of comorbidities revealed that individuals with diabetes mellitus (DM) were significantly more likely to have periodontitis (aOR = 1.4 and 95% CI = 1.18-1.68).

CONCLUSIONS

In a rapidly increasing Korean population, the lower socioeconomic groups as well as individuals with DM were significantly more likely to present with periodontitis.

Single-stage extracranial carotid artery stenting and intracranial aneurysm coiling: technical feasibility and clinical outcome

The coexistence of carotid artery stenosis and cerebral aneurysm in a patient presents challenges for treatment decision-making. The purpose of this study was to evaluate the technical feasibility and clinical outcome after single-stage extracranial carotid artery stenting (CAS) and ipsilateral intracranial aneurysm coiling in a single institution. From March 2005 to February 2011, 17 patients with 21 aneurysms underwent single-stage CAS and coiling for ipsilateral aneurysms. There were symptomatic atherosclerotic carotid stenoses with unruptured aneurysms in eight, ruptured or symptomatic aneurysms with simultaneous asymptomatic carotid stenoses in two and asymptomatic lesions in seven. CAS was followed by aneurysm coiling in all 17 patients. Clinical and radiological data were reviewed. There were two procedure-related complications: acute in-stent thrombosis in one and premature aneurysmal rupture in the other. After aneurysm coiling, complete occlusion was demonstrated in 17 aneurysms and near-total occlusion in four. No neurological deficit was found at discharge and follow-up outcomes were excellent in all the patients (mean, 32.9 months). Follow-up imaging studies were performed in all the patients, including neck CT angiography in 14 (mean, 26.1 months), brain MR angiography in 14 (mean, 31.2 months), and conventional angiography in three (mean, 14.7 months). They revealed two asymptomatic, mild carotid re-stenoses and one major aneurysmal recanalization requiring re-coiling. A single-stage CAS and coiling procedure appears to be feasible and the complication rate seems to be reasonable. We suggest that there is no need for separate therapeutic procedures when a patient has carotid artery stenosis and accompanying ipsilateral intracranial aneurysm.

Lipopolysaccharide-induced indoleamine 2,3-dioxygenase expression in the periodontal ligament

BACKGROUND AND OBJECTIVE

Indoleamine 2,3-dioxygenase (IDO) is a tryptophan-oxidizing enzyme with immune-inhibitory effects. The aim of this study was to investigate the expression of IDO by lipopolysaccharide (LPS), a component of gram-negative bacteria, in human periodontal ligament (PDL) cells.

MATERIAL AND METHODS

Human PDL cells and gingival fibroblasts (GFs) were prepared from explants of human PDLs and from gingival tissues of clinically healthy donors, respectively. Real-time RT-PCR, western blotting and the IDO enzyme assay were performed to determine the expression of IDO following LPS treatment of cells. LPS was injected into mice tail veins to evaluate the effects of LPS in vivo in the maxillary first molar. Immunofluorescence staining and histological analysis were followed to localize IDO in mouse PDL.

RESULTS

The level of expression of IDO mRNA in primary human PDL cells after LPS treatment was increased in a dose-dependent manner, reaching a peak 8 h after LPS treatment. The expression and activities of IDO protein were significantly increased in comparison with those of the control. In addition, the increased production of kynurenine in culture medium was observed 72 h after LPS treatment. In the immunofluorescence findings, stronger immunoreactivities were shown in PDL than in gingival tissues in the maxillae. In accordance with the immunofluorescence findings, LPS treatment induced a strong up-regulation of IDO mRNA in human PDL cells, whereas human GFs showed only a weak response to LPS.

CONCLUSION

These results clearly show that IDO was induced by LPS in primary human PDL cells, suggesting that PDL might be involved in the regulation of oral inflammatory disease.

SHP is involved in BMP2-induced odontoblast differentiation

Small Heterodimer Partner (SHP) interacts with diverse transcription factors such as Runx2 and regulates many cellular events including differentiation, proliferation, and energy metabolism. SHP is reported to be a positive regulator of BMP2-induced bone formation. This study aimed to clarify the role of SHP in odontoblast differentiation and matrix mineralization. Rat tooth germs were isolated, and gene expression was determined by RT-PCR and real-time PCR. Localization of SHP protein expression was identified by immunofluorescent analysis. Primary human dental pulp cells (HDPCs) were cultured with BMP2 and/or Ad-siSHP. Matrix mineralization was evaluated by Alizarin red staining. Transient transfection experiment was performed with the SHP or Dlx5 expressional plasmids and the DSPP gene. In tooth germs from post-natal days 3 to 9, BMP-2 and SHP expression increased with DSPP and DMP1 mRNA expression. In an immunostaining study, SHP was expressed in odontoblasts and surrounding osteoblasts. When HDPCs were cultured with BMP2 in mineralization-inducing medium, SHP expression also increased with an increase in DSPP expression. Down-regulation of SHP by Ad-siSHP inhibited matrix mineralization. In transient transfection experiments, overexpression of SHP was shown to enhance DSPP promoter activity through interactions between SHP and Dlx5. These results suggest that SHP may mediate BMP2 signaling to promote mineralization of the dentin matrix.

Efficacy of leukotriene receptor antagonist for erosive esophagitis: a preliminary retrospective comparative study

While diagnostic overlap exists between gastroesophageal reflux disease and eosinophilic esophagitis especially on histological findings, therapeutic approaches for the two disease entities are very different. Recently, anti-inflammatory treatment, in addition to acid suppressants, has been investigated for gastroesophageal reflux disease. This study investigated whether the incidence of endoscopic erosive esophagitis was lower in recipients of long-term leukotriene receptor antagonist (LTRA) treatment. This retrospective comparative study included 207 recipients of an LTRA and an equal number of controls who underwent screening upper endoscopic examination. Twenty-two (10.6%) and 51 (24.6%) cases of erosive esophagitis were detected in the LTRA and control groups, respectively (P < 0.001). A significantly higher incidence of minimal change esophagitis was also found in the controls compared with the LTRA group (14.5% vs. 2.4%, P < 0.001). On multivariate analysis, LTRA treatment was significantly and inversely associated with erosive esophagitis (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.13 to 0.46). Within the LTRA treatment group, an increased risk of erosive esophagitis was strongly associated with the presence of hiatal hernia (OR, 5.89; 95% CI, 2.20-15.73, P < 0.001) and short duration of LTRA treatment (OR, 0.64; 95% CI, 0.37-0.89, P= 0.022). In conclusion, this preliminary retrospective analysis demonstrated that patients who underwent long-term treatment with a LTRA had low incidence of endoscopic minimal change esophagitis.

Unexpected synchronous follicular lymphoma of paraaortic and pelvic lymph nodes in a patient with endometrial carcinoma: a case report

BACKGROUND

Multiple neoplasms in a patient occur rarely. There has only been one case report about synchronous endometrial carcinoma and follicular lymphoma of the paraaortic and pelvic lymph node (LN) until now.

CASE REPORT

The patient was 64 years old and had vaginal spotting for four months. She was diagnosed with endometrioid endometrial carcinoma by endometrial biopsy. In intraoperative inspection, the whole paraaortic and pelvic LN had formed into a massive tumor bundle following the aorta and iliac vessels. The diagnosis was endometrial carcinoma FIGO Stage IB with synchronous follicular lymphoma Stage III. We performed adjuvant chemotherapy and radiotherapy. Currently, the patient has no evidence of recurrence for either carcinoma.

CONCLUSION

Lymph node dissection was included in the staging and debulking operation of the endometrial carcinoma. An inaccurate result of the frozen section can not rule out metastasis of endometrial carcinoma and surgeons can fall into a dilemma regarding treatment.

Wear performance of self-mating contact pairs of TiN and TiAlN coatings on orthopedic grade Ti-6Al-4V

Both titanium nitride (TiN) and titanium aluminum nitride (TiAlN) have shown great wear resistance potential in metallic medical devices as protective, hard thin film coatings. In the present study, the effects of TiN and TiAlN coating layers on the wear performance of Ti-6Al-4V were compared and analyzed. TiN and TiAlN coatings with a thickness of 3 microm were deposited by a cathodic vacuum arc ion plating technique on the surface of Ti-6Al-4V. Wear tests were conducted by using a pin-on-disk-type tribotester with a point contact self-mating pair in a linear reciprocal motion. A sliding distance of 20 mm per cycle at 1 Hz was used under a load of 15 N under ambient conditions with no lubricant. The wear resistance of TiN and TiAlN coatings is superior to that of uncoated Ti-6Al-4V at the early stage of sliding contact. Until a measurable amount of wear was detected, the number of sliding cycles of the TiAlN coating pair was longer than TiN. After the first detection of wear from the coating layers, the rate of wear of the TiN coating pairs was significantly higher than that of TiAlN (p < 0.05), and it was close to that of the uncoated pairs. In conclusion, the TiAlN coating is superior to TiN from the viewpoint of wear resistance under the test conditions used in this study.

Histologic diagnosis based on forceps biopsy is not adequate for determining endoscopic treatment of gastric adenomatous lesions

BACKGROUND AND STUDY AIMS

Controversy persists around the treatment of gastric low-grade dysplasia (LGD). The aim of this study was to investigate possible indications for the endoscopic resection of gastric LGD through analysis of the histologic discrepancies between specimens of gastric LGD obtained by forceps biopsy and by endoscopic mucosal resection (EMR), and of their clinicopathologic characteristics.

PATIENTS AND METHODS

The study involved 293 gastric LGD that were histologically proven on the basis of forceps biopsy in Severance Hospital between January 2004 and December 2007. Twenty cases were regularly followed up, and the remaining 273 were resected by EMR. We performed univariate and multivariate analyses of clinical and endoscopic characteristics including lesion size, number of biopsy fragments, and endoscopic appearance, in order to analyze the factors affecting histologic discrepancies.

RESULTS

Of the 273 lesions resected by EMR, 207 (75.8 %) showed concordant histology, whereas for 51 (18.7 %) the histology was upgraded after endoscopic resection. Lesion size, absence of whitish discoloration, and the presence of spontaneous bleeding were found by univariate analysis to be statistically significant factors predicting an upgraded histology after EMR ( P = 0.026, P < 0.001, and P = 0.025, respectively). Multivariate analysis also showed absence of whitish discoloration to be a statistically significant factor influencing histologic discrepancies ( P = 0.001, odds ratio 5.29, 95 % confidence interval 1.95 - 14.37). Perforation and bleeding rates associated with EMR for LGD were 0.7 % and 6.2 %, respectively. Twenty patients who did not undergo EMR were followed up for a mean of 22 months, and 3 were revealed to have adenocarcinoma and 1 high-grade dysplasia on the latest histologic exam.

CONCLUSIONS

We should consider endoscopic resection for gastric LGD that are 2 cm or more in size and do not have whitish discoloration.

Evaluation of a new cataract surgery referral pathway

AIMS

To compare the quality of referrals and listing rates of direct optometric referrals vs traditional GP referrals for cataract surgery.

METHODS

A retrospective cohort of 124 patients referred for cataract surgery was identified (62 via optometric pathway and 62 via GP pathway). The quality of the referral was assessed by establishing if it contained adequate information relating to the College of Optometrists' referral framework document. Age, sex, drug history, listing rate, operative rate, and visual acuity (best corrected) at referral and at the postoperative visit were recorded and compared between the two referral pathways using the Fisher's exact test.

RESULTS

Optometric referrals, relative to GP referrals, were more likely to include information relating to objective visual loss (100 vs 87%, P=0.0061) and to counsel the patient (97 vs 18%, P=0.0001). GP referrals, relative to optometric referrals, were more likely to comment on personal circumstances (32 vs 3%, P=0.0001), past medical history (95 vs 68%, P=0.0001), and drug history (94 vs 69%, P=0.0009). Operative rates were higher for the optometric direct referrals relative to GP referrals (87 vs 69%, P=0.0284). There was no difference in the visual acuity before or after surgery between the pathways.

CONCLUSIONS

Optometric direct cataract referrals provide better information on objectively measured vision and better delivery of preoperative counselling. Traditional GP referrals contain better medical history, drug information, and details of personal circumstances. Rates of surgery were slightly higher with optometric referrals.

Completion sleeve pneumonectomy for suture line recurrence of lung cancer after sleeve lobectomy

The most appropriate treatment for suture line recurrence of lung cancer after bronchial sleeve lobectomy is completion pneumonectomy. While completion pneumonectomy may not be justified from an oncological point of view due to the positive bronchial resection margin, completion tracheal sleeve pneumonectomy is an optimal surgical procedure. We carried out two cases of completion tracheal sleeve pneumonectomy for suture line recurrence of lung cancer after bronchial sleeve lobectomy of the right upper lobe and achieved good results, which suggests that completion tracheal sleeve pneumonectomy for suture line recurrence after bronchial sleeve lobectomy is a good treatment modality for selected patients.

Protective effects of green tea polyphenol against reactive oxygen species-induced oxidative stress in cultured rat calvarial osteoblast

The injurious effects of reactive oxygen species on osteoblasts and the potential protective role played by green tea polyphenols (GtPP) were investigated using primarily cultured rat calvarial osteoblasts. Oxidative stress was induced in cultured osteoblasts, either by adding 100 mmol/L H2O2 or by the action of 40 U/L xanthine oxidase (XO) in the presence of xanthine (250 micromol/L). After incubation, the cellular viability, function and morphology were evaluated. Both treatments produced a significant reduction in osteoblast viability, as assessed by a two-colored fluorescence staining method combined with flow cytometric analysis and MTT assay. A significant reduction in the alkaline phosphatase activity was observed after H2O2 addition, whereas XO did not have the same effect. On the microscopic observations, the morphological changes and intracellular ultrastructural damages were remarkably induced by both treatments. The H2O2-induced alterations were prevented by pre-incubating the osteoblasts with 200 microg/ml GtPP for 1 h. When the oxidative stress was induced by XO, the cellular viability and morphology was also maintained at the same polyphenol concentration. These results demonstrate that GtPP can act as a biological antioxidant in a cell culture experimental model and protect cells from oxidative stress-induced toxicity.

Oxygen dynamics in petroleum hydrocarbon contaminated salt marsh soils: III. A rate model

A model describing oxygen dynamics due to crude oil biodegradation under flooded conditions in saltwater wetlands was developed. The model is composed of three non-linear ordinary differential equations (ODEs) that simulate oxygen uptake, cell growth, and oil degradation simultaneously. The model equations were solved by using a stiff version of ODE solver, ODEPACK, which employs a multistep method and allows the change of step sizes and order of methods (ie., Gear's method). The results of model simulation were compared with experimental data obtained from a fully aerated microcosm study. The results of model simulation indicate that dissolved oxygen concentration in the overlying water rapidly depleted below 3 mg l(-1) unless the reaeration coefficient was higher than 2.0 day(-1). Active aerobic biodegradation of crude oil did not occur under flooded conditions because (i) dissolved oxygen is rapidly depleted, (ii) reaeration is not sufficient enough to replenish dissolved oxygen and (iii) the oil dissolution rate constant decreases over time. The model may lead to better understanding of oxygen demand for a long bioremediation period. The results of this study may be applicable for the establishment of an engineered bioremediation strategy.

Effects of environmental endocrine disruptors on the sex differentiation in Korean rockfish, Sebastes schlegeli

The effects of estradiol-17beta, methyltestosterone, tributyltin, bisphenol A and 2,4-dinitrophenol on sex differentiation were investigated in the Korean rockfish, Sebastes schlegeli. The 51 day-old fry with undifferentiated gonads were fed with food containing the chemicals at 0.05, 0.5, 5, 50 and 100 micro/g diet for 29 days. Sex ratio and gonadal abnormality after the chemical treatment were determined by histological examination of gonads. In control group, the sex ratio of fry was 1:1.3 (female:male), and more males than females appeared. The sex of fry fed with estradiol-17beta at 5, 50 and 100 micro/g diet was all females. Feminization of the fry was induced by exogenic estradiol-17beta. In the methyltestosterone group, sex ratio of fry was 1:10.2 in 0.05 micro/g diet, 1:2.4 in 0.5 micro/g diet, 1:3.1 in 5 micro/g diet, 1:1.2 in 50 micro/g diet and 1:2.3 in 100 micro/g diet. Masculinization of the fry was induced by methyltestosterone at the lowest concentration. Furthermore, intersex of the fry was observed. The number of intersex fry was 23.3, 25.0 and 35.3 at 0.5, 5 and 50 micro/g diet of methyltestosterone, respectively. Sex ratio of bisphenol A group showed no difference with that of the control. The sex of fry fed with 2,4-dinitrophenol at 5, 50 and 100 micro/g diet was all females. 2,4-dinitrophenol should be considered as a new member of endocrine disruptors. In tributyltin group, the sex ratio of fry at 100 micro/g diet of tributyltin was 5.4:1. Tributyltin induced the feminization of the fry at the highest dose. Tributyltin showed an estrogenic effect in the Korean rockfish in contrast to an androgenic effect in gastropods.

Antibiotic selective pressure for the maintenance of antibiotic resistant genes in coliform bacteria isolated from the aquatic environment

Coliform bacteria isolated from the aquatic environment were investigated for antibiotic susceptibility and detailed structures of class 1 integrons. A high proportion of isolates were found to be resistant to sulfamethoxazole, aminoglycosides, and beta-lactams. The 750 (53.6%) isolates were resistant to one or more of the antibiotics tested out of 1,400 coliform bacteria. Based on the MIC of antibiotics and antibiogram, 150 isolates were selected and further studied for class 1 integrons. The intI1 gene was found in 36 (24.0%) of the 150 isolates. Twelve isolates carried the gene cassettes responsible for antibiotic resistance, while no gene cassettes were found in 24 isolates. Seven different genes, dfrA5, dfrA7, dfrA12, dfrA17, aaA2, aaA5, and aad(3'), were detected in gene cassettes. The dfrA and aad genes located on class 1 integrons were responsible for resistance to trimethoprim and aminoglycosides. The remaining 24 coliform bacteria had the incomplete or non-functional class 1 integrons. These results indicated that antibiotic selective pressures may play an important role to maintain gene cassettes of class 1 integrons and in the absence of sustained antibiotic pressures, such as the aquatic environment, coliform bacteria may carry empty or non-functional class 1 integrons.

Study on the inhibitory effects of Korean medicinal plants and their main compounds on the 1,1-diphenyl-2-picrylhydrazyl radical

A 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-generating system was used to evaluate the antioxidant properties of Korean medicinal plants that have been used widely as folk medicines for several disorders, as well as compounds isolated from them. Among the Rosaceae, Rosa rugosa and Rosa davurica showed strong DPPH radical-scavenging activity. The most effective medicinal plant from families other than Rosaceae was Cedrela sinensis, followed in order by Nelumbo nucifera, Eucommia ulmoides, Zanthoxylum piperitum, Cudrania tricuspidata and Houttuynia cordata. These results serve as a good index of the free radical-scavenging activities of Korean medicinal plants. Furthermore, the polyphenols isolated from these plants, procyanidin B-3, (+)-catechin, gallic acid, methyl gallate, quercetin, quercetin-3-O-beta-D-glucoside, quercetin-3-O-beta-galactoside, quercetin-3-O-rutinose and kaempferol, exerted strong DPPH radical-scavenging activity. These results suggest that the Korean medicinal plants and the polyphenols isolated from them that exhibited effective radical-scavenging activity may be promising agents for scavenging free radicals and treating diseases associated with excess free radicals.

The synthetic peptide, His-Phe-Tyr-Leu-Pro-Met, is a chemoattractant for Jukat T cells

His-Phe-Tyr-Leu-Pro-Met (HFYLPM) is a synthetic peptide that stimulates Jurkat T cells resulting in intracellular calcium ([Ca2+]i) increase in a pertussis toxin (PTX)-sensitive manner. We have examined the physiological role of the peptide in T cell activity by comparative investigation of intracellular signaling pathways accompanied with HFYLPM-induced T cell chemotaxis with a well-known chemokine, stromal cell-derived factor-1 (SDF-1)-induced signalings. Wortmannin and genistein inhibited both of HFYLPM- and SDF-1-induced Jurkat T cell chemotaxis indicating that phosphoinositide-3-kinase and tyrosine kinase activity were required for the processes. However, U-73122 and BAPTA/AM preferentially blocked HFYLPM- but not SDF-1-induced T cell chemotaxis. It indicates that phospholipase C/calcium signaling is necessary for only chemotaxis by HFYLPM. One of the well-known cellular molecules involving chemotaxis, extracellular signal-regulated protein kinase (ERK), was activated by SDF-1 but not by HFYLPM ruling out a possible role of ERK on the peptide-mediated chemotaxis. These results indicate that the synthetic peptide, HFYLPM, stimulates T cell chemotaxis showing unique signaling and provide a useful tool for the study of T cell activation mechanism.

p21(WAF1) is associated with CDK2 and CDK4 protein during HL-60 cell differentiation by TPA treatment

TPA-treated HL-60 cells are mainly arrested in G1 by p21(WAF1) accumulation. We investigate the downstream changes following such accumulation. Increased p21(WAF1) is associated with CDK2 and CDK4. pRb is dephosphorylated in the presence of p21-CDK2/4 complexes, and the Rb-E2F1 complex increases after TPA treatment, whereas the Rb-HDAC1 complex decreases slightly. Our results suggest that increased p21(WAF1) is associated with CDK2/4, and that these complexes induce pRb dephosphorylation. In turn, hypophosphorylated pRb are mainly complexed with E2F1, but HDAC1 appears not to be a key component in this process.

Comparative study on motility of the cultured fetal and neonatal dermal fibroblasts in extracellular matrix

One of the differences between fetal and adult skin healing is the ability of fetal wounds heal without contraction and scar formation. Extracellular matrix (ECM) provides a substratum for cells adhesion, migration, and proliferation and can directly influence the form and function of cells. As motility is essential for many important biological events, including wound healing, inflammatory response, embryonic development, and tumor metastasis, this study was designed to compare the motilities cultured dermal fetal and neonatal fibroblasts in the extracellular matrix. The motility of cultured fetal and neonatal fibroblasts was compared using a video-microscopy system that was developed in combination with a self-designed CO2 mini-incubator. To determine migration speed, cells were viewed with a 4X phase-contrast lens and video recorded. Images were captured using a color CCD camera and saved in 8-bit full-color mode. We found that cultured fetal fibroblasts move faster than neonatal fibroblast on type I collagen (fetal fibroblast, 15.1 micrometer/hr; neonatal fibroblast, 13.7 micrometer/hr), and in fibronectin (fetal fibroblast, 13.2 micrometer/hr; neonatal fibroblast, 13.0 micrometer/hr) and hyaluronic acid (fetal fibroblast, 11 micrometer/hr; neonatal fibroblast, 9.8 micrometer/hr).

Demonstration of Epstein-Barr virus in odontogenic and nonodontogenic tumors by the polymerase chain reaction (PCR)

BACKGROUND

Although considerable insight has been gamed into Epstein-Barr virus (EBV) as an important etiologic factor in various tumors, virtually little is known about the relationship between EBV genes and oral tumors.

METHOD

Thirty-two cases of nonodontogenic tumor (16 squamous cell carcinomas, 11 salivary gland tumors, 1 malignant lymphoma, 1 spindle cell sarcoma, 1 osteogenic sarcoma, 1 malignant fibrous histiocytoma and 1 verrucous carcinoma), 17 cases of odontogenic tumor (17 ameloblastomas, the most important and common type of odontogenic tumor) and 12 cases of normal oral tissue (8 normal gingival tissues and other oral mucosa) were examined for the presence of EBV-DNA, with primers specific for the BamW, BNRF1, BMLF1, BamC, IR3, BMRF1, EBNA-2A BamhY, and EBNA-2B BamhY region of the EBV genome by the polymerase chain reaction (PCR).

RESULTS

Fifty-three percent (17/32) of nonodontogenic tumors, forty-eight percent (8/17) of ameloblastomas, and ninety-two percent (11/12) of normal oral tissues were positive for EBV-DNA. Of the EBV-DNA, BMLF1 demonstrated the strongest reactivity in the nonodontogenic tumors, and BamC demonstrated the strongest reactivity in the ameloblastomas and normal oral mucosae.

CONCLUSIONS

Taken into account with the expression of different EBV genes in odontogenic and nonodontogenic tumors, these findings suggest that even though odontogenic tumors and nonodontogenic tumors are relatively unique, the appearance of different EBV genes seems to suggest the complicated roles that the EBV genes play.

Effects of presurgical and post-surgical irradiation on the healing process of Medpor in dogs

The purpose of this study was to determine the effect of irradiation on the healing process and the effect on the contact surface of Medpor and bone. Eighteen dogs were studied. The animals were divided into three groups. Six non-irradiated dogs served as controls (Group 1). Twelve dogs irradiated on the left femur, before and after implantation of Medpor, were studied. The dogs were euthanized 4 and 8 weeks after Medpor was implanted in presurgical irradiation subgroup animals (Group 2) and after the completion of irradiation in post-surgical irradiation subgroup animals (Group 3). Light microscopic and scanning electron microscopic examinations were performed. The appearance of osteoblasts and bone matrix formation were remarkably late and manifest slight reactions in post-surgical irradiation group compared to the control group presenting the osteoblasts at 4 weeks, and those osteoblasts were not visible in presurgical irradiation group in both the 4-week and 8-week observation. We concluded that the bone remodeling was delayed in the irradiated bone, especially in the presurgical group.