1,200 research outputs found
The effect of radiotherapy on survival of dental implants in head and neck cancer patients
Objectives: To explore the current literature of the survival of dental implants in irradiated head and neck cancer
patients considering the role of implant location, bone augmentation, dose of radiation and timing of implant placement.
Study Design: Pubmed search was conducted to identify articles published between January 2000 and December
2014 and presenting data of dental implant survival with radiotherapy in head and neck cancer patients. Studies on
animal subjects and craniofacial implants were excluded.
Results: 18 articles out of 27 were eligible for inclusion in this systematic review. 12 out of 18 studies reported
favorable outcome of dental implants and radiotherapy with survival rates between 74.4% and 97%. Seven out
of ten studies comparing the survival rates according to site of implant placement reported that implants were
found to osseointegrate with greater success in the irradiated mandible than irradiated maxilla. 5 studies which
compared implant survival in irradiated native bone versus irradiated grafted bone reported that irradiated grafted
bone showed a significantly reduced dental implant survival rate in comparison to irradiated native bone. 6 out of
18studies in which radiation doses exceeded 70 Gy reported lower survival rates of dental implants in comparison
to the studies in which radiation doses were ≤70Gy. Higher survival rates were reported in 2 studies in which implants
placement was before radiotherapy in comparison to the remaining 16 studies in which implants placement
was after radiotherapy.
Conclusions: Dental implants may be affected by radiotherapy especially when they are placed in maxilla, in grafted
bone, or after radiation, however, they remain a functional option for rehabilitation of head and cancer patients.
More prospective cohort studies and randomized controlled trails are still needed to draw more evidence based
conclusion
Predictors of Human Immunodeficiency Virus Knowledge among Jordanian Youths
Objectives: Understanding factors associated with the level of human immunodeficiency virus (HIV) knowledge acquisition is crucial to inform preventative programmes for young people. This study examines predictors of HIV knowledge among Jordanian youths. Methods: A cross-sectional survey was conducted among 8,129 youths aged between 14 and 25 years randomly selected from schools representing each of the 12 governorates of Jordan. A total of 50% of respondents were female and, on average, 17 years old. Participants completed a self-administered questionnaire covering sociodemographic characteristics, HIV knowledge, gender awareness, exposure to and favourable attitudes toward risky behaviours. Results: On a 13-item HIV knowledge test, participants answered an average of 7 questions correctly (mean = 7.21; standard deviation = 2.63). Female respondents from rural areas demonstrated significantly lower levels of HIV knowledge, while college and university students demonstrated higher levels. HIV knowledge differed significantly by sources of information, with peeracquired information associated with more accuracy, while HIV information from parents or health centres was associated with a lower score. Youths with more egalitarian gender views also demonstrated higher knowledge levels, whereas youths approving of drug use showed lower levels of HIV knowledge. Conclusion: HIV education programmes in Jordan should focus on females and youths living in rural areas. Educational institutions have been shown to be effective in providing accurate information to students, while parents and health professionals should also be included in HIV prevention programmes in order to reduce misconceptions and raise the level of HIV knowledge among Jordanian youths
A Test of the Eikonal Approximation in High-Energy (e,e'p) Scattering
The Glauber method is extensively used to describe the motion of a hadronic
projectile in interaction with the surrounding nuclear medium. One of the main
approximations consists in the linearization of the wave equation for the
interacting particle. We have studied the consequences of such an assumption in
the case of the reaction
at high proton momenta by comparing the results with the predictions obtained
when all the ingredients of the calculation are unchanged but the second-order
differential equation for the scattered wave, which is solved exactly for each
partial wave up to a maximum of 120 spherical harmonics. We find that the
Glauber cross section is always larger by a factor , even at
vanishing missing momenta. We give a quantum-mechanical explanation of this
discrepancy. Nevertheless, a good correlation is found between the two
predictions as functions of the missing momentum, especially in parallel
kinematics.Comment: LaTeX, 8 pages, 4 figures uuencoded, accepted for publication on
Phys. Lett.
Modal dependent type theory and dependent right adjoints
In recent years we have seen several new models of dependent type theory
extended with some form of modal necessity operator, including nominal type
theory, guarded and clocked type theory, and spatial and cohesive type theory.
In this paper we study modal dependent type theory: dependent type theory with
an operator satisfying (a dependent version of) the K-axiom of modal logic. We
investigate both semantics and syntax. For the semantics, we introduce
categories with families with a dependent right adjoint (CwDRA) and show that
the examples above can be presented as such. Indeed, we show that any finite
limit category with an adjunction of endofunctors gives rise to a CwDRA via the
local universe construction. For the syntax, we introduce a dependently typed
extension of Fitch-style modal lambda-calculus, show that it can be interpreted
in any CwDRA, and build a term model. We extend the syntax and semantics with
universes
Chance of healthy versus adverse outcome in subsequent pregnancy after previous loss beyond 16 weeks: data from a specialized follow-up clinic
PURPOSE: Women with a previous fetal demise have a 2-20 fold increased risk of another stillbirth in a subsequent pregnancy when compared to those who have had a live birth. Despite this, there is limited research regarding the management and outcomes of subsequent pregnancies. This study was conducted to accurately quantify the chances of a woman having a healthy subsequent pregnancy after a pregnancy loss. METHODS: A retrospective study was conducted at a tertiary-level unit between March 2019 and April 2021. We collected data on all women with a history of previous fetal demise attending a specialized perinatal history clinic and compared the risk of subsequent stillbirth to those with a normal pregnancy outcome. Outcome data included birth outcome, obstetric and medical complications, gestational age and birth weight and mode of delivery. Those who had healthy subsequent pregnancies were compared with those who experienced adverse outcomes. RESULTS: A total of 101 cases were reviewed. Ninety-six women with subsequent pregnancies after a history of fetal demise from 16 weeks were included. Seventy-nine percent of women (n = 76) delivered a baby at term, without complications. Overall, 2.1% had repeat pregnancy losses (n = 2) and 2.1% delivered babies with fetal growth restriction (n = 2). There were no cases of abruption in a subsequent pregnancy. Eighteen neonates were delivered prematurely (18.4%), 15 of these (83.3%) were due to iatrogenic causes and three (16.7%) were spontaneous. In univariable logistic regression analyses, those with adverse outcomes in subsequent pregnancies had greater odds of pre-eclampsia (Odds ratio *(OR) = 3.89, 95% CI = 1.05-14.43, p = .042) and fetal growth restriction (OR = 4.58, 95% CI = 1.41-14.82, p = 0.011) in previous pregnancies compared to those with healthy outcomes. However, in multivariable logistic regression analyses, neither variable had a significant odds ratio (OR = 2.03, 95% CI = 0.44-9.39, p = .366 and OR = 3.42, 95% CI = 0.90 - 13.09, p = .072 for pre-eclampsia and FGR, respectively). CONCLUSION: Four in five women had a healthy subsequent pregnancy. This is a reassuring figure for women when contemplating another pregnancy, particularly if cared for in a specialist clinic
Gene editing restores dystrophin expression in a canine model of Duchenne muscular dystrophy
Mutations in the gene encoding dystrophin, a protein that maintains muscle integrity and function, cause Duchenne muscular dystrophy (DMD). The deltaE50-MD dog model of DMD harbors a mutation corresponding to a mutational “hotspot” in the human DMD gene. We used adeno-associated viruses to deliver CRISPR gene editing components to four dogs and examined dystrophin protein expression 6 weeks after intramuscular delivery (n = 2) or 8 weeks after systemic delivery (n = 2). After systemic delivery in skeletal muscle, dystrophin was restored to levels ranging from 3 to 90% of normal, depending on muscle type. In cardiac muscle, dystrophin levels in the dog receiving the highest dose reached 92% of normal. The treated dogs also showed improved muscle histology. These large-animal data support the concept that, with further development, gene editing approaches may prove clinically useful for the treatment of DMD
Lip and oral lesions in children with Down syndrome: a controlled study
Background: Down syndrome (DS) is the most common chromosomal abnormality affecting numerous organs,
including the orofacial region. The objective of the present study was to assess the prevalence of lip and oral soft
tissue lesions, with particular emphasize on the incidence of fissured tongue, lip fissures and angular cheilitis,
among individuals with DS in Yemen.
Material and Methods: This controlled cross-sectional study included 50 children with DS (6-18 years), and 50 age-
and gender-matched healthy controls. The prevalence of orofacial soft tissue lesions was evaluated in both groups.
Data were analyzed by Chi-square and Fisher tests, and
p
<0.05 was considered to be statistically significant.
Results: Ten orolabial lesions were identified among the subjects. The most frequently seen lesions were: Fissured
tongue (78.0%), lip fissures (64.0%), angular cheilitis (38.0%) and Cheilitis (14.0%). The frequencies of these
lesions were significantly higher in children with DS than healthy controls (
P
< 0.001). Most of lip fissures were in
the lower lip, and 80% of the fissures were in the midline.
Conclusions: The prevalence of lip and oral lesions among individuals with DS is remarkably high. Hence, oral
physicians should be more aware of the orofacial findings seen more frequently in this genetic disorder
Digital Single-Cell Analysis of Plant Organ Development Using 3DCellAtlas
Diverse molecular networks underlying plant growth and development are rapidly being uncovered. Integrating these data into the spatial and temporal context of dynamic organ growth remains a technical challenge. We developed 3DCellAtlas, an integrative computational pipeline that semiautomatically identifies cell types and quantifies both 3D cellular anisotropy and reporter abundance at single-cell resolution across whole plant organs. Cell identification is no less than 97.8% accurate and does not require transgenic lineage markers or reference atlases. Cell positions within organs are defined using an internal indexing system generating cellular level organ atlases where data from multiple samples can be integrated. Using this approach, we quantified the organ-wide cell-type-specific 3D cellular anisotropy driving Arabidopsis thaliana hypocotyl elongation. The impact ethylene has on hypocotyl 3D cell anisotropy identified the preferential growth of endodermis in response to this hormone. The spatiotemporal dynamics of the endogenous DELLA protein RGA, expansin gene EXPA3, and cell expansion was quantified within distinct cell types of Arabidopsis roots. A significant regulatory relationship between RGA, EXPA3, and growth was present in the epidermis and endodermis. The use of single-cell analyses of plant development enables the dynamics of diverse regulatory networks to be integrated with 3D organ growth
Management and birth outcomes of pregnant women with Chiari malformations : a 14 years retrospective case series
Objective
The management of Chiari malformations in pregnancy is challenging due to the perceived risk of adverse maternal neurological outcomes and raising intracranial pressure during labour. Our aim was to evaluate the management and health outcomes of pregnant women cared for at a regional referral center and highlight elements of best practice.
Study Design
A retrospective case series of all pregnant women diagnosed with Chiari malformation over fourteen years (January 2004- June 2018) at the Birmingham Women’s Hospital – UK.
Results
Twenty-one women (23 pregnancies) with Chiari malformation were included, four had syringomyelia (4/21,19%) and six had previously undergone craniovertebral decompression (6/21, 29%). The median age was 34-years (range 20-41), the median gravidity was two (range 1-8), the median parity was one (range 0-6), and the median extent of tonsillar herniation was 11 mm (range 9-18). The majority of women received their preferred mode of delivery (15 normal vaginal deliveries (15/23, 65.2%) and 6 elective Caesarean sections (6/23, 26.1%)) with two pregnancies ending with an emergency caesarean section for obstetric complications (2/23, 8.7%). Five Caesarean section were performed under general anaesthetic, two under spinal (2/23, 8.7%) and one under epidural anaesthesia (1/23, 4.3%) with no neurological sequelae. There were no adverse neurological outcomes at discharge postnatally.
Conclusions
Offering normal vaginal delivery with effective analgesia, for women with Chiari malformation, appears to be safe. Pregnancy care should be provided by a multi-disciplinary team with experience in managing Chiari malformation
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