In vitro evaluation of estrogenic, antiestrogenic and antitumor effects of amentoflavone.

Apigenin, a flavonoid, is reported to act as an estrogen receptor (ER) agonist and inhibit aromatase enzyme. However, amentoflavone, a biflavonoid bearing two apigenin molecules, has not been evaluated for its endocrine modulatory effects. Besides, it is highly consumed by young people to build muscles, enhance mood and lose weight. In the present study, apigenin was used as a reference molecule and ER mediated as well as ER-independent estrogenic/antiestrogenic activity of amentoflavone was investigated. Antitumor activity of amentoflavone was also investigated in both ER positive (MCF-7 BUS) and triple-negative (MDA-MB-231) breast cancer cells and its cytotoxicity was evaluated in human breast epithelial cells (MCF-10A). Our data confirmed ER agonist, aromatase inhibitory and cytotoxic effects of apigenin in breast cancer cells, where no ER mediated estrogenic effect and physiologically irrelevant, slight, aromatase inhibition was found for amentoflavone. Although selective cytotoxicity of amentoflavone was found in MCF-7 BUS cells, it does not seem to be an alternative to the present cytotoxic drugs. Therefore, neither an adverse effect, mediated by an estrogenic/antiestrogenic effect of amentoflavone nor a therapeutical benefit would be expected from amentoflavone. Further studies could be performed to investigate its in vivo effects.

In vitro antioxidant/prooxidant effects of combined use of flavonoids.

The present study was undertaken to investigate the individual and combined antioxidant or prooxidant effects of genistein, daidzein and quercetin in human erythrocytes and rat microsomes in vitro. Their reducing potential against oxidation of a redox sensitive fluorescent probe, their protective effect against H2O2-induced membrane lipid peroxidation and their inhibitory effect on AAPH-induced hemolysis were evaluated. Genistein and daidzein were prooxidant in erythrocytes but antioxidant in microsomes where their metabolites might have been formed which suggests the importance of metabolic capacity in in vitro models to predict the physiological situation. Quercetin showed antioxidant effects in all models and conditions. Prooxidant effect of 'genistein-daidzein mixture', at their concentrations reflecting the real life, was suppressed by addition of quercetin to the mixture. Our study shows that flavonoids can exert prooxidant effects depending on the conditions, but the mixture effect should be considered while assessing their effects and safety in humans.

R202Q/M694V as novel MEFV gene mutations in chronic periodontitis and familial Mediterranean fever.

BACKGROUND AND OBJECTIVE: Familial Mediterranean fever (FMF) and chronic periodontitis are inflammatory diseases leading to an increase in the number of inflammasomes. To date, no published studies have reported on mutations in the Mediterranean fever (MEFV) gene in patients with chronic periodontitis, although the roles of MEFV gene mutations in FMF and FMF-associated amyloidosis (FMF-A) are well known. Therefore, the aim of this study was to evaluate the frequencies of MEFV gene mutations and serum amyloid A (SAA) and high-sensitivity C-reactive protein (hs-CRP) levels in patients with chronic periodontitis, FMF and FMF-A. MATERIAL AND METHODS: The study population included 122 patients with FMF and 128 subjects who were systemically healthy. Clinical periodontal parameters, including the plaque index, gingival index, probing pocket depth, clinical attachment level and percentage of bleeding on probing were recorded. Blood samples were obtained from patients with FMF and systemically healthy controls, and all mutations located on exons 2 and 10 of the MEFV gene were analyzed by DNA Sanger Sequencing, which is the gold standard. SAA and high-sensitive CRP levels were also assessed. RESULTS: Mean gingival index, percentage of bleeding on probing, probing pocket depth and clinical attachment level, and the levels of SAA and hs-CRP were higher in the FMF-A group than those in the FMF and control groups. The two most relevant mutations in patients with FMF were heterozygous M694V (46.2%), and heterozygous R202Q (32.7%). The frequencies of the homozygous M694V and R202Q mutations in the FMF-A group were 53.8% and 46.1%, respectively. The complex R202Q/M694V homozygous state led to an increased risk of chronic periodontitis (odds ratio: 3.6), and FMF-A (odds ratio: 7.6). CONCLUSION: This is the first study to report the R202Q mutation in patients with periodontitis. Furthermore, the MEFV gene-mediated inflammatory pathway increased serum acute phase reactants, and the changes in the R202Q and M694V could play a role in inflammatory-genetic diseases, such as FMF, FMF-associated amyloidosis and chronic periodontitis.

Unenhanced respiratory-navigated NATIVE® TrueFISP magnetic resonance angiography in the evaluation of renal arteries: Comparison with contrast-enhanced magnetic resonance angiography.

PURPOSE: To compare unenhanced three-dimensional (3D) NATIVE® true fast imaging with steady-state precession (TrueFISP) magnetic resonance (MR) angiography with the more conventional MR angiography technique obtained after intravenous administration of a gadolinium chelate in the evaluation of renal arteries and their branches in patients with suspected renal artery stenosis. MATERIALS AND METHODS: A total of 39 patients (25 men, 14 women) with a mean age of 51.4±17.5years (SD) (range: 10-82years) were included in the study. All patients with suspected renal artery stenosis underwent unenhanced 3D NATIVE® TrueFISP MR angiography and contrast-enhanced MR angiography. The two MR angiography methods were compared by two independent readers for image quality using a four-point scale, diagnostic performance and grading of renal artery stenosis on a total of 78 renal arteries. RESULTS: For both readers image quality of unenhanced 3D NATIVE® TrueFISP MR angiography (3.12 to 3.63) was greater than that of contrast-enhanced MR angiography (1.94 to 2.71) for renal artery ostium-trunk and the left renal artery segmental branches. The sensitivity of 3D NATIVE® TrueFISP MR angiography for the diagnosis of renal artery stenosis was 100% for both readers for the right renal artery and 66% and 80% for the left renal artery for reader 1 and reader 2, respectively. Agreement between 3D NATIVE® TrueFISP MR angiography and CE-MR angiography was 95% (74/78) for reader 1 and 92% (72/78) for reader 2. CONCLUSION: Unenhanced NATIVE® TrueFISP magnetic resonance angiography can play an additional role in the evaluation of renal arteries in patients with hypertension, especially in subjects at risk of nephrogenic systemic fibrosis.

General health and oral health status in elderly dental patients in Isparta, Turkey.

The aim of this study was to describe the oral health, general health status and medication use of elderly dental patients 709 voluntary patients, aged 60 years and over, who attended Suleyman Demirel University Faculty of Dentistry for routine dental treatment between March 2008 and April 2009 in Isparta, Turkey, were interviewed for demographic data, systemic diseases, and lists of medications. The majority of the patients (84.4%) had poor oral hygiene according to the Oral Hygiene Index (OHI). The mean level of the study population's decayed, missing, and filled teeth (DMFT) index score was 19.1 ± 7.3. The prevalence of systemic diseases was high (90%). Women were affected by a significantly higher incidence of systemic diseases than men (96.4% vs. 84.3%; P < 0.001). The percentage of the elderly taking medication regularly was 72.6%. Drug adverse effects were determined in 25.5% of the study population, with more adverse effects observed in women (53.3%) than men (46.7%) (P < 0.001).Dentists must be aware of the dental implications that may arise from systemic diseases and medications and should properly modify elderly patients' treatment accordingly.

General health and oral health status in elderly dental patients in Isparta, Turkey

The aim of this study was to describe the oral health, general health status and medication use of elderly dental patients 709 voluntary patients, aged 60 years and over, who attended Suleyman Demirel University Faculty of Dentistry for routine dental treatment between March 2008 and April 2009 in Isparta, Turkey, were interviewed for demographic data, systemic diseases, and lists of medications. The majority of the patients [84.4%] had poor oral hygiene according to the Oral Hygiene Index [OHI]. The mean level of the study population's decayed, missing, and filled teeth [DMFT] index score was 19.1 +/- 7.3. The prevalence of systemic diseases was high [90%]. Women were affected by a significantly higher incidence of systemic diseases than men [96.4% vs. 84.3%; P < 0.001]. The percentage of the elderly taking medication regularly was 72.6%. Drug adverse effects were determined in 25.5% of the study population, with more adverse effects observed in women [53.3%] than men [46.7%] [P < 0.001]. Dentists must be aware of the dental implications that may arise from systemic diseases and medications and should properly modify elderly patients' treatment accordingly

La présente étude avait pour objectif de décrire la santé bucco-dentaire de patients dentaires âgés, leur état de santé général et leur recours aux médicaments; 709 patients volontaires, âgés de 60 ans et plus, qui avaient consulté à la Faculté de Dentisterie de l'Université de Suleyman Demirel pour des soins dentaires de routine entre mars 2008 et avril 2009 à Isparta, en Turquie, ont été interrogés pour obtenir des données démographiques, ainsi qu'au sujet des maladies systémiques et des listes de médicaments qui les concernaient. La majorité des patients [84,4%] avaient une mauvaise hygiène bucco-dentaire selon l'indice d'hygiène buccale. Le niveau moyen de l'indice CAO [dent cariée, absente ou obturée] de la population étudiée était de 19,1 +/- 7,3. La prévalence des maladies systémiques était élevée [90%]. Les femmes étaient significativement plus affectées par les maladies systémiques que les hommes [96,4% contre 84,3% ; p < 0,001]. Le pourcentage de personnes âgées pregnant des médicaments sur une base régulière était de 72,6%. Les effets secondaires provoqués par les medicaments ont été déterminés pour 25,5% de la population étudiée, avec davantage d'effets secondaires observés chez les femmes [53,3%] que chez les hommes [46,7%] [p <0,001]. Les dentistes doivent avoir connaissance des implications dentaires pouvant être causées par des maladies systémiques et des traitements médicamenteux, et devraient modifier les soins apportés aux personnes âgées en conséquence

Effects of periodontal treatment on inflammation and oxidative stress markers in patients with metabolic syndrome.

BACKGROUND AND OBJECTIVE: Metabolic syndrome (MetS) is a combination of risk factors (e.g. impaired glucose tolerance, hypertension, and dyslipidaemia) that significantly contribute to the development of cardiovascular diseases. The aim of the study was to compare the effects of nonsurgical periodontal treatment (NSPT) on inflammatory and oxidative stress markers in individuals with MetS and systemically healthy (SH) who were chronic periodontitis (CP). MATERIAL AND METHODS: A total of 50 patients with chronic periodontitis (25 with MetS and 25 SH) were included. Clinical periodontal measurements were recorded, and serum and whole-saliva samples were collected from all patients at baseline, and 3 and 6 mo following NSPT. The levels of fasting plasma glucose, glycated haemoglobin (HbA1c), triglyceride (TRG), total cholesterol, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol were analysed. The levels of high-sensitivity C-reactive protein (hs-CRP), interleukin (IL)-6 and IL-10 were determined using ELISA kits, and total oxidant status (TOS), total antioxidant capacity (TAC) and oxidative stress index (OSI) levels were measured. RESULTS: After NSPT, significant and similar improvements of all periodontal parameters were observed in both groups compared with baseline measurements. There were decreases in the levels of serum hs-CRP and IL-6, whereas increases in serum IL-10 were found in both groups, at all time points. Serum TOS and OSI showed no significant change in either group at any time point. Compared with the SH group, serum TAC levels were higher in the MetS group at baseline but lower at the 3-mo time-point. There was no difference in TAC levels between the groups at 6 mo. Saliva IL-6 was higher in the MetS group than the SH group at all time points. The levels of IL-6 and OSI in saliva decreased following NSPT in both groups, whereas salivary TAC concentrations increased. In the MetS group, TRG and HbA1c levels decreased significantly at 3 mo. CONCLUSION: NSPT decreased oxidative stress and the inflammatory status of patients with MetS and chronic periodontitis. Although similar periodontal improvements were achieved in both groups, the decreases in levels of hs-CRP and IL-6 in the MetS group did not reach the levels in the SH group. Based on these results, NSPT could be more effective in the control of systemic inflammation in patients with MetS in the short-term.

Examining the aetiopathogenesis of varicoceles: the relationship between retroperitoneal adipose tissue and testicular venous drainage.

This study evaluated the effect of retroperitoneal adipose tissue on testicular venous drainage and tested the nutcracker phenomenon by clinical and imaging findings. A total of 95 patients were included. The patients were evaluated with a detailed medical history and physical examination for varicocele. Their weight, height and waist circumference were also recorded. Body mass index was calculated as weight (kg)/height squared (m(2) ). Pampiniform plexus diameters were measured by scrotal colour Doppler ultrasonography, and retroperitoneal adipose tissue was evaluated by noncontrast abdominal computed tomography. We determined an almost significant correlation between BMI and varicocele presence by physical examination (P = 0.06). However, there was a significant relationship between WC and varicocele identified by physical examination (P = 0.021). There was a positive and significant relationship between BMI and pampiniform plexus diameters. Furthermore, we detected a negative correlation between retroperitoneal adipose tissue measurements and CDU findings. Additionally, there was a significant correlation between WC, pampiniform plexus diameters and CT findings. It is concluded that increasing BMI and increasing WC may play a protective role in the development of varicocele. There is a need for further studies to verify the effect of obesity on varicocele formation.

Effects of strontium ranelate on sutural bone formation: a histological and immunohistochemical study.

AIM: Rapid maxillary expansion is performed to correct a skeletal transverse deficiency of the maxilla, which is a frequently- encountered orthodontic anomaly. Strontium ranelate (SrR) is a novel agent that has a dual action, involving anti-resorptive and bone-forming effects. The aim of this study was to evaluate the effects of systemically applied SrR on osteoblastic bone formation after maxillary expansion on the mid-palatal suture of rats using histological and immunohistochemical tests. MATERIALS AND METHODS: A total of 24 Wistar rats were randomly divided into two equal groups. In all animals, five-day inter-premaxillary expansion was applied and maintained for a seven-day retention period, during which 625mg/kg/day SrR diluted with saline solution was administered orally to the experimental group. The rats were sacrificed and the tissues prepared for histological and immunohistochemical examinations after the retention period. RESULTS: Osteoblastic activity and the width of the blood vessels in the suture area were significantly increased in the SrR group compared with the control group (p < 0.051. Ossification was also observed to be active under light microscopy by staining with hematoxylin and eosin in the experimental group. Immunohistochemical labelling performed using osteonectin, osteocalcin, TGF-P and VEGF antibodies revealed significant immunoreactivity in the experimental group (p < 0.05). CONCLUSION: It may be concluded that SrR contributed to stimulatory osteogenesis in the expansion region. Therefore, a retention period may be shortened and relapse possibly reduced, following the application of SrR after the expansion.

Radiographic evaluation of third-molar development in relation to the chronological age of Turkish children in the southwest Eastern Anatolia region.

To study the chronological age of third-molar mineralisation of Turkish children from the southwest Eastern Anatolia region, the Demirjian staging method was used to determine the stage of the mineralisation of four third molars (18, 28, 38 and 48) and to compare third-molar development by sex and age with the results of previous studies. The study comprised 832 Turkish children from the southwest Eastern Anatolia region aged 6-16 years based on radiological evidence from digital orthopantomograms. The mean age of the 832 patients was 11.03±1.98 years, with 424 males (mean age, 10.97±1.97) and 408 females (mean age, 11.09±2.00). The orthopantomograms were scored by two observers. The Wilcoxon matched-pairs signed-rank test used to assess intra- and inter-observer assessment revealed strong agreement between both observers' measurements. Statistical analysis of the association between sex and age was performed with the Mann-Whitney U-test and the Wilcoxon test. Regression analysis was performed to obtain regression formulae for calculating the dental and the chronological age. The statistical analysis showed a strong correlation between age and third-molar development in males (R(2)=0.61) and females (R(2)=0.63). New equations (age=7.49+0.69, development stage (DS) 38+0.70, DS18) were derived for estimation of the chronological age. The results showed that there was no significant difference in mineralisation between 18 and 28 and 38 and 48 in males or females. For both sexes, the dental age was lower than the chronological age. Males reached the developmental stages earlier than females. In the whole population, the boys' and the girls' dental ages were 0.84 years and 0.16 years earlier, respectively, than their chronological ages. The use of third-molar teeth as a developmental marker is suitable, particularly when comparing the obtained standard deviation with other skeletal-age calculation techniques.

A retrospective radiographic study of coronal-periapical status and root canal filling quality in a selected adult Turkish population.

OBJECTIVE: To investigate the oral health (with regard to the periapical status, quality of root fillings and coronal restorations) in an urban adult Turkish subpopulation using digital panoramic radiographs. MATERIALS AND METHODS: One thousand digital panoramic radiographs involving 28,000 teeth were selected from the archive of the Public Oral and Dental Health Center of Isparta. Coronal status (the type of restoration, signs of marginal leakage or decay), root filling quality (length and lateral seal) and periapical status (according to Periapical Index, PAI) were evaluated. Correlations between apical periodontitis (AP) and the quality of root fillings or coronal restorations were statistically analyzed using the χ(2) test. RESULTS: Of the 28,000 teeth evaluated, 22,380 (80.0%) were sound, 4,732 (16.9%) were missing, 753 (2.6%) were filled and 135 (0.5%) were decayed. Of the 753 coronal restorations, 400 (53.1%) were radiographically acceptable. Of the 23,268 teeth, 601 (2.6%) were root filled and 247 root fillings were adequate. Ninety-five (15.8%) root-filled teeth had AP (PAI 3-5). Out of the total, the AP prevalence was 0.4% in root-filled teeth and 0.8% in teeth without root fillings. The presence of AP was significantly correlated with inadequate coronal restorations and root canal fillings (p = 0.000). CONCLUSION: Tooth type, quality and type of coronal restorations, and length and homogeneity of root fillings significantly affected periapical status.

Managing radiation use in medical imaging: a multifaceted challenge.

This special report aims to inform the medical community about the many challenges involved in managing radiation exposure in a way that maximizes the benefit-risk ratio. The report discusses the state of current knowledge and key questions in regard to sources of medical imaging radiation exposure, radiation risk estimation, dose reduction strategies, and regulatory options.

Off-label use of medical products in radiation therapy: summary of the report of AAPM Task Group No. 121.

Medical products (devices, drugs, or biologics) contain information in their labeling regarding the manner in which the manufacturer has determined that the products can be used in a safe and effective manner. The Food and Drug Administration (FDA) approves medical products for use for these specific indications which are part of the medical product's labeling. When medical products are used in a manner not specified in the labeling, it is commonly referred to as off-label use. The practice of medicine allows for this off-label use to treat individual patients, but the ethical and legal implications for such unapproved use can be confusing. Although the responsibility and, ultimately, the liability for off-label use often rests with the prescribing physician, medical physicists and others are also responsible for the safe and proper use of the medical products. When these products are used for purposes other than which they were approved, it is important for medical physicists to understand their responsibilities. In the United States, medical products can only be marketed if officially cleared, approved, or licensed by the FDA; they can be used if they are not subject to or specifically exempt from FDA regulations, or if they are being used in research with the appropriate regulatory safeguards. Medical devices are either cleared or approved by FDA's Center for Devices and Radiological Health. Drugs are approved by FDA's Center for Drug Evaluation and Research, and biological products such as vaccines or blood are licensed under a biologics license agreement by FDA's Center for Biologics Evaluation and Research. For the purpose of this report, the process by which the FDA eventually clears, approves, or licenses such products for marketing in the United States will be referred to as approval. This report summarizes the various ways medical products, primarily medical devices, can legally be brought to market in the United States, and includes a discussion of the approval process, along with manufacturers' responsibilities, labeling, marketing and promotion, and off-label use. This is an educational and descriptive report and does not contain prescriptive recommendations. This report addresses the role of the medical physicist in clinical situations involving off-label use. Case studies in radiation therapy are presented. Any mention of commercial products is for identification only; it does not imply recommendations or endorsements of any of the authors or the AAPM. The full report, containing extensive background on off-label use with several appendices, is available on the AAPM website (http://www.aapm.org/pubs/reports/).

Entrance surface dose and image quality: comparison of adult chest and abdominal X-ray examinations in general practitioner clinics, public and private hospitals in Malaysia.

This study was undertaken to compare the entrance surface dose (ESD) and image quality of adult chest and abdominal X-ray examinations conducted at general practitioner (GP) clinics, and public and private hospitals in Malaysia. The surveyed facilities were randomly selected within a given category (28 GP clinics, 20 public hospitals and 15 private hospitals). Only departmental X-ray units were involved in the survey. Chest examinations were done at all facilities, while only hospitals performed abdominal examinations. This study used the x-ray attenuation phantoms and protocols developed for the Nationwide Evaluation of X-ray Trends (NEXT) survey program in the United States. The ESD was calculated from measurements of exposure and clinical geometry. An image quality test tool was used to evaluate the low-contrast detectability and high-contrast detail performance under typical clinical conditions. The median ESD value for the adult chest X-ray examination was the highest (0.25 mGy) at GP clinics, followed by private hospitals (0.22 mGy) and public hospitals (0.17 mGy). The median ESD for the adult abdominal X-ray examination at public hospitals (3.35 mGy) was higher than that for private hospitals (2.81 mGy). Results of image quality assessment for the chest X-ray examination show that all facility types have a similar median spatial resolution and low-contrast detectability. For the abdominal X-ray examination, public hospitals have a similar median spatial resolution but larger low-contrast detectability compared with private hospitals. The results of this survey clearly show that there is room for further improvement in performing chest and abdominal X-ray examinations in Malaysia.

Preventive effect of aminoguanidine compared to vitamin E and C on cisplatin-induced nephrotoxicity in rats.

In this study, the antioxidant effect of aminoguanidine on nephrotoxicity of a single dose of cisplatin is investigated and compared with the effects of well-known antioxidants vitamin C and E combination. Tubular damage and perivascular inflammation were observed in kidney samples of the cisplatin-administered groups. Aminoguanidine and vitamin C-E combination are found to be capable of preventing these effects of cisplatin. Liver tissues of all groups were intact. Cisplatin-induced oxidative stress was evidenced by significant decrease in glutathione and significant increase in malondialdehyde levels in kidney samples. Antioxidants with cisplatin decreased malondialdehyde levels. Antioxidants with cisplatin prevented the decrease in liver glutathione levels. The nephrotoxicity was confirmed biochemically by significant elevation of serum urea and creatinine levels. Both vitamin C-E combination and aminoguanidine prevented the increase in serum urea levels according to the cisplatin group.

Hepatocerebral form of mitochondrial DNA depletion syndrome: novel MPV17 mutations.

BACKGROUND: Autosomal recessive mutations in MPV17 (OMIM *137960) have been identified in the hepatocerebral form of mitochondrial DNA depletion syndrome (MDS). OBJECTIVE: To describe the clinical, morphologic, and genetic findings in 3 children with MPV17-related MDS from 2 unrelated families. DESIGN: Case report. SETTING: Academic research. MAIN OUTCOME MEASURES: We identified 3 novel pathogenic mutations in 3 children. RESULTS: Two children were homozygous for nonsense mutation p.W120X. A third child was compound heterozygous for missense mutation p.G24W and for a macrodeletion spanning MPV17 exon 8. All patients demonstrated lactic acidosis, hypoglycemia, hepatomegaly, and progressive liver failure. Neurologic symptoms manifested at a later stage of the disease. Death occurred within the first year of life in all 3 patients. CONCLUSIONS: These data confirm that MPV17 mutations are associated with a 2-stage syndrome. The first symptoms are metabolic and rapidly progress to hepatic failure. This stage is followed by neurologic involvement affecting the central and peripheral systems.

Micropush-out bond strengths of gutta-percha versus thermoplastic synthetic polymer-based systems - an ex vivo study.

AIM: To compare the interfacial strength and failure mode of root fillings consisting of different technique-material combinations. METHODOLOGY: Human mandibular premolars (n = 144) instrumented to apical size 40 and .06 taper were divided into 12 experimental groups. The root canals were filled with either gutta-percha (groups 1-6) or Resilon (groups 7-12) core materials combined with AH Plus (groups 1, 4, 7, 10), Ketac-Endo (groups 2, 5, 8, 11) or Epiphany (groups 3, 6, 9, 12) using cold lateral compaction (groups 1-3, groups 7-9) or System B with Obtura II (groups 4-6, groups 10-12). Three serial 1.00 +/- 0.05-mm-thick root slices were prepared and push-out tests on the filling material were performed. Interactions amongst the compaction techniques, core materials and sealers were analysed using a three-way analysis of variance (anova) (P < 0.05). One-way anova and Duncan's Multiple Range tests were used to compare the bond strengths of the 12 groups. Fracture modes of all root slices were evaluated stereomicroscopically at x40 magnification. RESULTS: All the parameters except compaction techniques had significant interactions (P < 0.05). A significant difference was found amongst the groups (P < 0.05). Gutta-percha/Ketac-Endo/cold lateral compaction and gutta-percha/AH Plus/cold lateral compaction groups had the highest micropush-out bond strength values (P < 0.05). The number of overall cohesive failures was significantly more than that of adhesive failures (P < 0.05). CONCLUSIONS: The push-out bond strengths of Resilon/Epiphany combinations were lower than those of gutta-percha/conventional root canal sealer combinations. Core materials and sealers may affect the push-out bond strengths of root canal filling materials.

The radioactive drug research committee: Background and retrospective study of reported research data (1975-2004).

In the United States, human research involving radioactive drugs must be conducted under a Food and Drug Administration (FDA) investigational new drug (IND) application, unless specifically exempt from IND requirements, or under the direct oversight of a Radioactive Drug Research Committee (RDRC) as long as certain conditions are met. Research overseen by RDRCs is considered basic science research when its purpose is to advance scientific knowledge and not to determine a radioactive drug's safety and effectiveness as a therapeutic, diagnostic, or preventive medical product in humans. We retrospectively reviewed and analyzed available study data from annual reports submitted to the FDA dating back to 1976. In 1976, there were 18 studies involving 531 subjects compared with 2003, when there were 284 RDRC studies involving 2,797 subjects. In 1976, RDRC subjects were imaged 5% of the time using positron-emitting nuclides and 77% of the time with conventional gamma-emitting nuclides. In 2003, this was reversed with 77% using positron emitters and 5% using conventional gamma-emitters. In 1976, pediatric studies comprised 7.3% of all RDRC subjects; today pediatric RDRC studies are rarely conducted. Today the RDRC is used primarily by large medical research institutions. Although the program has a very good safety record, RDRC's 30-y-old regulations need to be revised to be consistent with current scientific knowledge and health policy.

Application of lipid peroxidation and protein oxidation biomarkers for oxidative damage in mammalian cells. A comparison with two fluorescent probes.

We recently developed two biomarker sets for oxidative damage: one for determination of lipid peroxidation (LPO) degradation products; acetaldehyde, propanal, butanal, pentanal, hexanal, heptanal, octanal, nonanal, malondialdehyde and acetone, by a gas chromatography-electron capture detection method, and the other for protein oxidation products such as o,o'-dityrosine, by an isotope dilution high performance liquid chromatography-tandem mass spectrometry method. In the present study, we explored the possibility to utilize these biomarkers for determining the oxidative damage in liver mammalian cells in vitro. Two different treatments were chosen for inducing oxidative stress in Chinese Hamster ovary cells: menadione and copper plus hydrogen peroxide (Cu2+/H2O2). Cells were incubated with the model compounds in the presence or absence of vitamin E and C, and cytotoxicity was evaluated by a nuclear-dye method. Results were compared to two fluorescent probes, H2DCF-DA and C11 -BODIPY581/591, which have been used for determining the formation of free radicals in the cells. From ten LPO degradation products, eight were increased significantly following incubation with menadione in cell lysate or incubation media. Menadione-induced oxidative stress was also confirmed by oxidation of fluorescent probes. However, no increased formation of protein oxidation products was observed. Vitamin E and C did not diminish the formation of LPO degradation products that were increased by menadione. Although Cu2+/H2O2 did not induce oxidation of fluorescent probes, it induced formation of six out of ten LPO degradation products. Vitamin E and C did not diminish the formation of LPO degradation products; vitamin C even substantially increased the formation of acetaldehyde and propanal, which is in line with its reported prooxidant action under certain conditions. Vitamin C also caused two-fold increase in Cu2+/H2O2-induced o,o'-dityrosine formation when applied simultaneously. In conclusion, our present results show that the LPO biomarker set can be used for evaluation of oxidant capacity and the toxic potential of various chemicals in an in vitro cell model. These biomarkers might even be more sensitive than measuring protein oxidation products or oxidation of fluorescent probes.

Reference values for diagnostic radiology: application and impact.

Reference values (RVs) are recommended by the American Association of Physicists in Medicine for four radiographic projections, computed tomography, fluoroscopy, and dental radiography. RVs are used to compare radiation doses from individual pieces of radiographic equipment with doses from similar equipment assessed in national surveys. RVs recommended by the American Association of Physicists in Medicine have been developed from the Nationwide Evaluation of X-ray Trends survey performed by the state radiation protection agencies with the cooperation and support of the U.S. Food and Drug Administration, the Conference of Radiation Control Program Directors, and the American College of Radiology. The RVs selected by the American Association of Physicists in Medicine represent, approximately, the 80th percentile of the survey distributions. Consequently, equipment exceeding the RVs is using higher radiation doses than is 80% of the equipment in the surveys. Radiation doses for specific projections, with standard phantoms, should be measured annually, as recommended by the American College of Radiology. When the RVs are exceeded, the medical physicist should investigate the cause and determine, in cooperation with the responsible radiologist, whether these doses are justified or the imaging system should be optimized to reduce patient radiation doses. RVs are a useful tool for comparing patient radiation doses at institutions throughout the United States and for providing information about radiographic equipment performance.