198,165 research outputs found
A novel protective prion protein variant that colocalizes with kuru exposure.
No full textBACKGROUND: Kuru is a devastating epidemic prion disease that affected a highly restricted geographic area of the Papua New Guinea highlands; at its peak, it predominantly affected adult women and children of both sexes. Its incidence has steadily declined since the cessation of its route of transmission, endocannibalism. METHODS: We performed genetic and selected clinical and genealogic assessments of more than 3000 persons from Eastern Highland populations, including 709 who participated in cannibalistic mortuary feasts, 152 of whom subsequently died of kuru. RESULTS: Persons who were exposed to kuru and survived the epidemic in Papua New Guinea are predominantly heterozygotes at the known resistance factor at codon 129 of the prion protein gene (PRNP). We now report a novel PRNP variant--G127V--that was found exclusively in people who lived in the region in which kuru was prevalent and that was present in half of the otherwise susceptible women from the region of highest exposure who were homozygous for methionine at PRNP codon 129. Although this allele is common in the area with the highest incidence of kuru, it is not found in patients with kuru and in unexposed population groups worldwide. Genealogic analysis reveals a significantly lower incidence of kuru in pedigrees that harbor the protective allele than in geographically matched control families. CONCLUSIONS: The 127V polymorphism is an acquired prion disease resistance factor selected during the kuru epidemic, rather than a pathogenic mutation that could have triggered the kuru epidemic. Variants at codons 127 and 129 of PRNP demonstrate the population genetic response to an epidemic of prion disease and represent a powerful episode of recent selection in humans
Effects of 810-nanometer diode laser as an adjunct to mechanical periodontal treatment on clinical periodontal parameters and gingival crevicular fluid volume of residual periodontal pockets
No full textBackground: Aim of this randomized controlled parallel-designed study was to evaluate the effects of diode laser as an adjunct to mechanical periodontal treatment on clinical parameters and gingival crevicular fluid (GCF) volume of the residual pockets diagnosed following initial periodontal treatment in chronic periodontitis (CP) patients. Materials and Methods: A total of 84 residual pockets on single-rooted teeth in 11 CP patients were included and randomly assigned into three groups. Residual pockets were treated either only by mechanical treatment (Group M) (n = 28) or only by diode laser disinfection (Group L) (n = 28) or by a combination of these techniques (Group M L) (n = 28). Plaque index, gingival index (GI), bleeding on probing (BoP), probing depth (PD), clinical attachment level and gingival recession were assessed at baseline and 8 weeks after treatment of residual pockets. GCF samples were collected at baseline, 1 and 8 weeks after treatment. Results: All treatment modalities resulted in significant reductions in PD and attachment gain. GI and BoP showed a greater reduction in both Group M and Group M L than Group L (P < 0.001), but there was no difference between the Groups M and M L (P 0.05). No difference was also found among groups for other clinical parameters. GCF volume decreased significantly in the Groups M and M L (P < 0.05) but there was no difference among the groups (P 0.05). Conclusion: Results demonstrated clinical improvements on residual pockets in CP patients treated with all three modalities. Moreover, our findings suggest that application of diode laser as an adjunct to mechanical periodontal treatment doesn't demonstrate any additional clinical effect on the residual pockets
Structural, dielectric and humidity properties of Al-Ni-Zn ferrite prepared by co-precipitation method
No full textAl0,2Ni0,3Zn0,5Fe2O4 ferrite nanoparticles have been synthesized by chemical co-precipitation method and structural characterization has been analyzed using X-Ray diffraction (XRD) and scanning electron microscopy (SEM). XRD analysis indicates that Al0,2Ni0,3Zn0,5Fe2O4 ferrite nanoparticles crystallize in the cubic spinel phase. To determine the electrical properties of the sample, the real and imaginary parts of the dielectric constant have been investigated to a frequency range from 20 Hz to 10 MHz for 31 test frequencies. These measurements have been also repeated for different temperatures. The impedance analysis of the sample was carried out using Nyquist curves. The variation of the conductivity of the sample is also shown for the 31 test frequencies and the different temperature values in the range between 293 K and 733 K. The DC conductivity of the Al0,2Ni0,3Zn0,5Fe2O4 as a function of temperature is also presented and the measurements confirm that the sample exhibits semiconductor behavior in accordance with the literature. Finally, the relative humidity, frequency and impedance map of the sample has been investigated in detail. (c) 2018 Elsevier B.V. All rights reserved
Flow cytometry analysis of guided tissue regeneration-associated human periodontal cells
No full textBackground: Expanded polytetrafluoroethylene (ePTFE) barrier membranes have been widely used for guided tissue regeneration (GTR) of the human periodontal ligament (PL). However, the precise cellular and molecular events involved in the re-growth of the new tissue are still unclear. Methods: Retrieved membranes and the newly -regenerated soft tissue (RT) underlying the membranes were used to examine the cells associated with GTR compared with normal human PL and gingival cells. Flow cytometry (FCM) was used, for the first time, to analyze the spindle-shaped fibroblast-like cells which were adherent to these membranes and the cells which grew out of the RT. Results: The results showed that the membrane-associated (M) cells had the lowest rate of proliferation and appeared to be larger and more granular than the other types of cell. Moreover, both the M- and RT-derived cells were found to express higher levels of the extracellular matrix (ECM) proteins Collagen type I, fibronectin, tenascin, and decorin. In addition, evidence based on FCM profiles identified distinct sub-populations of GTR cells in which fibronectin expression was markedly up-regulated compared with normal PL cells and which also differed in size and granularity. Conclusions: The results of this study show that cells associated with GTR barrier membranes and with the underlying tissue appear to have distinct phenotypic and functional activities consistent with the production of new periodontal connective tissue and periodontal regeneration
Serebral palsi tanılı çocuklarda görsel geri bildirim kullanımı ile üst ekstremite eğitimi
No full textPurpose: This study aimed to investigate that if upper limb visual feedback training added to the usual therapy was effective on
upper limb functions in children with cerebral palsy.
Methods: Thirty-eight children with cerebral palsy (4-18 years) participated in the study. The participants were randomly
assigned into two groups. Study group (n=19, mean age 8.50±3.40, 53% female) received visual feedback training plus usual
therapy twice a week for 8 weeks, 16 sessions in total, while control group (n=19, mean age 10.60±3.80, 42% female) received
only usual therapy. The participants’ Gross Motor Function Classification System levels were between I-III and spasticity levels
were between ‘0’ to ‘1+’ according to Modified Ashworth Scale. Upper limb range of motion (ROM), grip and pinch strength,
hand skills (Minnesota Manual Dexterity Test (MMDT)), and functional abilities (Childhood Health Assessment Questionnaire
(CHAQ)) were assessed before and after treatment.
Results: The change amount in shoulder flexion (p=0.004) and abduction (p=0.01), supination (p=0.019) and wrist flexion
(p=0.004) and extension (p=0.00) ROM values; bilateral MMDT scores (p=0.003) were statistically significantly improved in
study group compared to control group.
Conclusion: Adding visual feedback training to the usual therapy program of children with cerebral palsy was found to be
effective in some outcome measurements such as upper limb ROM and hand skills. In the long-term rehabilitation process, this
new training method may be an alternative additive option for children, families, and physiotherapists.Amaç: Bu çalışmanın amacı, serebral palsi tanısı olan çocuklarda rutin tedaviye eklenen üst ekstremite görsel geribildirim
eğitiminin üst ekstremite fonksiyonları üzerine etkisini araştırmaktı.
Yöntem: Çalışmaya serebral palsi tanılı (4-18 yaş) 38 çocuk katıldı. Katılımcılar randomize olarak iki gruba ayrıldı. Çalışma
grubu (n=19, ortalama yaş 8,50±3,40, %53 kadın) 8 hafta boyunca haftada 2 kez görsel geribildirim eğitimi ve rutin tedavi
alırken, kontrol grubu (n=19, ortalama yaş 10,60±3,80, %42 kadın) sadece rutin tedavi aldı. Kaba Motor Fonksiyonel
Sınıflandırma Sistemi seviyeleri I-III arasında ve spastisite seviyeleri Modifiye Ashworth Ölçeği’ne göre "0" ile "1+" arasında
olan çocuklar çalışmaya dahil edildi. Üst ekstremite hareket açıklığı (EHA), kavrama ve çimdik gücü, el becerileri (Minnesota
Manual Dexterity Test (MMDT)) ve fonksiyonel yetenekler (Childhood Health Assessment Questionnaire (CHAQ)) tedavi öncesi
ve sonrasında değerlendirildi.
Bulgular: Çalışma grubunda omuz fleksiyonu (p=0,004) ve abdüksiyon (p=0,01), supinasyon (p=0,019) ve bilek fleksiyonu
(p=0,004) ve ekstansiyon (p=0,00) EHA değerleri; bilateral MMDT puanları (p=0,003) kontrol grubuna göre istatistiksel olarak
anlamlı şekilde gelişti.
Sonuç: Görsel geribildirim eğitimini serebral palsi tanısı ile rehabilitasyon uygulanan çocukların tedavi programına eklemenin
üst ekstremite EHA ve el becerileri gibi bazı sonuç ölçümlerinde etkili olduğu bulundu. Uzun süreli rehabilitasyon sürecinde bu
yeni yöntem çocuklar, aileler ve fizyoterapistler için tedaviye eklenebilecek alternatif bir seçenek olabilir
Alkaline phosphatase activity is unregulated in regenerating human periodontal cells
No full textThe activity of alkaline phosphatase (ALP) is considered to indicate the presence of osteoblast cells and the formation of new bone. In the present study this enzyme was investigated in cells obtained from retrieved polytetrafluoroethylene membranes (M cells) of periodontal disease patients treated by guided tissue regeneration (GTR) and from the regenerated tissue underlying the membrane (RT cells). Normal periodontal ligament (PL) and gingival cells were also grown from the corresponding healthy tissues of human subjects. ALP activity was measured colourimetrically, using paranitrophenyl phosphate as the substrate, after 4 and 7 d of culture in the absence and presence of dexamethasone (DEX), a synthetic glucocorticoid which induces osteoblast differentiation. The results showed that basal levels of ALP activity were expressed by all the cells and that DEX upregulated ALP levels in the M, RT and PL cells but not in the gingival cells. Moreover, both the basal and DEX-induced ALP activities were statistically significantly higher in the RT cells than in any of the other cells. Our results suggest that both the GTR-associated and normal PL cells express osteoblast-like characteristics and, furthermore, that the RT cultures in particular contain a high proportion of osteoprogenitor cells
Oral health in patients on inhaled corticosteroid treatment
No full textObjective: The aim of this study was to investigate the effects of long-term inhaled corticosteroids on bone mineral density (BMD) of the mandible in relation with the tooth loss. Design: Cross sectional analytic study. Subjects and Methods: Patients (n=30) with chronic obstructive pulmonary disease under inhaled corticosteroid therapy for at least 1 year were compared with sex- and age-matched healthy controls (n=30). BMD of the mandible was measured by dual-energy X-ray absorptiometry. The clinical examination included recording the number of teeth present together with periodontal condition. Levels of serum osteocalcin, alkaline phosphatase, calcium, phosphorus and cortisol were also assessed. Results: BMD of the mandible in patients on corticosteroid treatment was significantly lower than that in the control group (P=0.001). Patients under treatment had more missing teeth than the control group but the difference did not reach statistical significance. The two groups exhibited similar clinical parameters of periodontal condition. Significantly lower levels of osteocalcin (P<0.0001), calcium (P=0.004) and cortisol (P=0.03) were observed in the patients on corticosteroid treatment. Conclusion: Long-term use of inhaled corticosteroids may impair bone metabolism and lead to a marked decrease in the mandibular BMD
The effect of spinal range of motion on functional balance, quality of life, and perception of appearance in adolescent idiopathic scoliosis after posterior spinal fusion surgery
No full textObjective: Spinal fusion, which is widely used in the surgical treatment of adolescent idiopathic scoliosis (AIS), limits the movements of the vertebral column. In this study, it was aimed to investigate the relationship between spinal mobility in the postoperative period with functional balance, quality of life, and perception of appearance in individuals with AIS. Methods: Thirty patients with AIS who underwent posterior spinal fusion surgery 1 to 3 years ago were included in the study. A universal goniometer was used to measure a spinal range of motion (ROM), functional reach test for functional balance, Scoliosis Research Society-30 (SRS-30) for quality of life, and Spinal Appearance Questionnaire (SAQ) for perception of appearance. Results: Surgical fusion length was significantly correlated with movements in the sagittal and transverse planes (r = − 0.383–[− 0.608]; p = < 0.001–0.037). Except for spinal left rotation, there was a significant positive correlation between functional balance level and ROM results (r = 0.374–0.523; p = 0.003–0.42). The SRS-30 total score correlated significantly with all other ROM measures except for rotations (r = 0.434–0.574; p = 0.00–0.016). SAQ total data correlated significantly with all ROM measurements (r = − 0.553–[− 0.395]; p = 0.002–0.031). Conclusions: In AIS, limitation of movement in the coronal, sagittal, and transverse planes is observed after fusion surgery. Spinal ROM is affected by the level of fusion performed at surgery. Postoperative spinal limitation of motion adversely affected functional balance, quality of life, and perception of appearance. We believe that comprehensive rehabilitation approaches that improve postoperative range of motion and increase functionality are important for optimal postoperative recovery
Osteocalcin and cross‑linked C‑terminal telopeptide of type I collagen in gingival crevicular fluid during piezocision accelerated orthodontic tooth movement: A randomized split‑mouth study
No full textBackground: Piezocision, a minimally invasive surgical procedure, has been used to accelerate tooth movement. Aim: The aim of this randomized split‑mouth study was to evaluate gingival crevicular fluid (GCF) osteocalcin (OC) and type I collagen cross‑linked C‑terminal telopeptide (ICTP) levels during canine distalization with and without piezocision acceleration. Material and Methods: Fifteen systemically healthy subjects (M:F 7:8, 16.27 ± 1.14 years) requiring extraction of maxillary first premolars before retraction of canines were included in the study. Piezocisions were randomly carried out on one of the maxillary canines while bilateral canines served as controls. Canine distalization was conducted using closed‑coil springs applying a force of 150 g/side by using miniscrews as anchorage. GCF sampling was performed from maxillary canine mesial and distal sites at baseline, 1, 7, 14, and 28 days. The GCF levels of OC and ICTP were detected by enzyme-linked immunosorbent assay (ELISA). The rate of tooth movement was evaluated at 2‑week intervals. Results: The amounts of canine distalization from baseline to 14 and 28 days in the piezocision group were significantly higher than the control group (P &lt; 0.05). The GCF OC level of the piezocision group on the tension side and the ICTP level of the same group on the compression side were higher than the respective sides of the control group on day 14 (P &lt; 0.05). Conclusions: Piezocision was found to be an effective treatment procedure for accelerating canine distalization accompanied by increased levels of OC and ICTP.Keywords: ICTP, osteocalcin, piezosurgey, tooth movemen
Denge döviz kuru: Gelişmekte olan ülkeler üzerine bir uygulama
No full textÖnemli makroekonomik değişkenlerden biri olan döviz kuru, ülkeler için rekabet gücünün bir göstergesidir. Son yıllarda gelişmekte olan ülkeler, küreselleşmenin etkisiyle döviz kuru dalgalanmalarıyla ve sürekli olarak cari açık sorunuyla karşılaşmaktadır. Özellikle 2000'li yıllarda yükselen reel efektif döviz kuru hareketlerinin olduğu Türkiye gibi çoğu gelişmekte olan ülkede, ulusal paranın değerindeki artışla birlikte cari açığın da arttığı görülmüştür. Bu nedenle reel efektif döviz kurunun denge değerinin belirlenmesi son zamanlarda sürekli tartışılan konuların başında gelmektedir. Türkiye'de, 2001 yılındaki krizden sonra reel efektif döviz kurunun değerlenme eğiliminde olduğu ve buna bağlı olarak aşırı değerli reel efektif döviz kurunun cari açığa katkı yaptığı düşünülmektedir. Bu amaçla çalışmada, Türkiye gibi cari açık sorunu yaşayan 15 gelişmekte olan ülke için 1995-2012 döneminde panel veri teknikleri kullanılarak denge döviz kuru tahminleri yapılmıştır. Buna göre Türkiye başta olmak üzere incelenen ülkelerde denge döviz kurundan sapmalar belirlenerek, reel anlamda kurların değeri tespit edilmiştir. Bu kapsamda denge döviz kuru, döviz kurundaki konjonktürel hareketleri açıklayan Davranışsal Denge Döviz Kuru Yaklaşımı (BEER) ve ekonomide iç ve dış dengeyle uyumlu döviz kurunun elde edilmesini sağlayan Temel Denge Döviz Kuru Yaklaşımı (FEER) ile tahmin edilmiştir. İki yaklaşımla elde edilen denge döviz kuru değerleri ve sapmaların seviyesi karşılaştırmalar yapılarak ekonomik dengeler açısından değerlendirilmiştir. FEER yaklaşımla yapılan analiz sonuçlarına göre, incelenen ülkelerin çoğunda cari reel efektif döviz kuru değerlerinin denge düzeyine yakın olduğu, BEER yaklaşım sonuçlarına göre ise cari reel efektif döviz kuru değerlerinin denge seviyelerinden oldukça farklılık gösterdiği tespit edilmiştir. Buna göre BEER yaklaşımla elde edilen döviz kuru sapmalarının FEER yaklaşıma göre oldukça yüksek olduğu görülmüştür. Sonuç olarak, bazı ülkelerde reel efektif döviz kurunun denge seviyesine göre düşük seviyede olmasına rağmen, Türkiye gibi bazı ülkelerde reel efektif döviz kurunun yüksek düzeyde olduğu bulunmuştur. Denge düzeyine göre düşük seviyeli reel efektif döviz kuruna sahip ülkelerde cari açık sorununun olması, bu ülkelerin üretim yapılarının ve dolayısıyla ihracatının ithalata bağımlı olduğunu göstermektedir. Aynı şekilde Türkiye gibi denge düzeyine göre yüksek reel efektif döviz kuruna sahip olan ülkelerde de ihracatın ithalata bağımlı yapı sergilediği görülmüştür. Buna göre Türkiye'de reel efektif döviz kurunun denge seviyesine göre yüksek düzeyde olmasının yanında ihracat yapısının ithalata bağımlı olmasının, cari açık seviyesini arttıran unsurlar olduğu tespit edilmiştir
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