Effect of dental implant cross-sectional design on cortical bone structure using finite element analysis

Purpose: This finite element analysis investigation evaluated the effect of different implant cross‐sectional designs on bone stress levels under different loading patterns. Materials and Methods: Finite element analysis program was used to construct four different three‐dimensional models describing 4 × 10‐mm implants in blocks of cortical and trabecular bone. A 5‐mm‐long abutment was modeled above each implant. The implant in model 1 was unthreaded, while in model 2 the implant was circularly threaded. The third implant in model 3 had the cross‐sectional shape as a 16‐sided star‐shaped design. The implant in model 4 was constructed unthreaded, with a diameter of 4.5 mm. Vertical and horizontal loads of 100 N each were applied on the top middle node of each implant assembly. All nodes at the bottom surface of the bone models were restrained. Results: By comparing models 1, 2, and 3, the lowest bone stress values under vertical and horizontal forces were observed around the unthreaded implant in model 1 (8.92 and 94.52 MPa, respectively). The highest stress value under vertical loading was shown around the threaded implant in model 2 (10.07 MPa), whereas the highest stress value under horizontal loading was observed around the star‐shaped implant in model 3 (108.40 MPa). Model 4, with a wider unthreaded design, had stress values under vertical and horizontal loading of 7.32 and 71.35 MPa, respectively. Conclusions: It was concluded that the unthreaded implant design produced the least bone stress. An increase in implant diameter could produce marked reduction in stress value in the bone around the neck of the implant.     

Intermittent preventive treatment in infants as a means of malaria control: a randomized, double-blind, placebo-controlled trial in northern Ghana

Morbidity and mortality from malaria remain unacceptably high among young children in sub-Saharan Africa. Intermittent preventive treatment in infancy (IPTi) involves the administration of antimalarials alongside routine vaccinations and might be an option in malaria control. In an area of intense, perennial malaria transmission in northern Ghana, 1,200 children received IPTi with sulfadoxine-pyrimethamine or placebo at approximately 3, 9, and 15 months of age. Children were followed up until 24 months of age to assess morbidity and adverse events. During the intervention period (3 to 18 months of age), IPTi reduced the incidences of malaria and severe anemia by 22.5% (95% confidence interval, 12 to 32%) and 23.6% (95% confidence interval, 4 to 39%), respectively, and reduced hospitalizations and episodes of asymptomatic parasitemia by one-third. Protection was pronounced in the first year of life and not discernible in the second. The malaria-protective effect was largely confined to a period of 1 month after sulfadoxine-pyrimethamine treatments. Following the intervention, protection against asymptomatic parasitemia persisted. In contrast, a significant rebound of severe malaria, predominantly severe malarial anemia, occurred among children having received IPTi. Although the treatment was generally well tolerated, one case of moderately severe skin reaction followed sulfadoxine-pyrimethamine treatment. IPTi reduces malaria and anemia in infants in northern Ghana. Extension of IPTi into the second year of life by administering a dose at 15 months of age provided no substantial benefit beyond a 1-month prophylactic effect. Although this simple intervention offers one of the few available malaria-preventive measures for regions where malaria is endemic, the observed rebound of severe malaria advises caution and requires further investigation.     

Personality predicts activity in reward and emotional regions associated with humor

Previous research and theory suggest that two stable personality dimensions, extroversion and neuroticism, differentially influence emotional reactivity to a variety of pleasurable phenomena. Here, we use event-related functional MRI to address the putative neural and behavioral associations between humor appreciation and the personality dimensions of introversion-extroversion and emotional stability-neuroticism. Our analysis showed extroversion to positively correlate with humor-driven blood oxygenation level-dependent signal in discrete regions of the right orbital frontal cortex, ventrolateral prefrontal cortex, and bilateral temporal cortices. Introversion correlated with increased activation in several regions, most prominently the bilateral amygdala. Although neuroticism did not positively correlate with any whole-brain activation, emotional stability (i.e., the inverse of neuroticism) correlated with increased activation in the mesocortical-mesolimbic reward circuitry encompassing the right orbital frontal cortex, caudate, and nucleus accumbens. Our findings tie together existing neurobiological studies of humor appreciation and are compatible with the notion that personality style plays a fundamental role in the neurobiological systems subserving humor appreciation.     

A Founder Effect of c.257 + 2T &gt; C Mutation in <Emphasis Type="Italic">NCF2</Emphasis> Gene Underlies Severe Chronic Granulomatous Disease in Eleven Patients

Chronic granulomatous disease (CGD) is the prototypic functional neutrophil disorder caused by genetic defects in one of the five genes encoding the superoxide-generating nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase subunits of phagocytes. Mutations causing the most prevalent form of CGD in western populations are located in the X-linked-CYBB gene. The four remaining autosomal recessive (AR) forms collectively account for one-third of CGD cases. We investigated the clinical and molecular features of eleven patients with CGD from 6 consanguineous families, originating from contiguous regions in the west of Tunisia. The patients’ clinical phenotype is characterized by a high incidence of mycobacterial infections. Five out of the eleven patients died despite treatment arguing in favor of a severe clinical form of CGD. These findings correlated with the absence of functional p67phox protein as well as the absence of residual reactive oxygen intermediates (ROI) production. Genetic analysis showed the presence, in all patients, of a unique mutation (c.257 + 2T > C) in NCF2 gene predicted to affect RNA splicing. Segregating analysis using nine polymorphic markers overlapping the NCF2 gene revealed a common haplotype spanning 4.1 Mb. The founder event responsible for this mutation was estimated to have arisen approximately 175 years ago. These findings will facilitate the implementation of preventive approaches through genetic counseling in affected consanguineous families.     

Chromosomal microarray analysis in a girl with mental retardation and spina bifida

Chromosomal imbalances comprise a major cause of mental retardation, particularly in association with congenital malformations and dysmorphic features. Chromosomal analysis using banded karyotyping is limited by the low resolution of this technique, and cryptic chromosomal rearrangements cannot be detected. We describe a 6-year-old girl with mental retardation, mild growth, congenital malformation, and facial anomalies. Chromosomal analysis with karyotyping produced normal results. Because the phenotype suggested chromosomal abnormality, microarray comparative genomic hybridization was used to search for a possible cryptic anomaly. A subtelomeric chromosomal imbalance, consisting of partial trisomy 2q35 and partial monosomy 3p26, was detected and confirmed using fluorescence in situ hybridization. This rearrangement was inherited from an equilibrated maternal t(2;3) reciprocal translocation. Comparative genomic hybridization array in similar situations is useful in detecting cryptic chromosomal rearrangements, identifying genes contained in deleted or duplicated regions, establishing a precise phenotype-genotype correlation, and offering unambiguous genetic counseling.     

Uveitis Referral Pattern in Upper and Lower Egypt

Purpose: To report the pattern of uveitis in two referral eye hospitals, one in Upper Egypt and another in Lower Egypt

Methods: Retrospective chart review of all uveitis cases visiting the uveitis clinic in Alexandria and Sohag University Hospitals between May 2010 and March 2017.

Results: A total of 1315 patients (683 in Upper Egypt and 632 in Lower Egypt) were identified. Uveitis was bilateral in 56.6% of patients in Upper Egypt and in 43.6% of patients in Lower Egypt. Anterior uveitis was the most common in both regions, accounting for 34.7% and 38.2% of cases in Upper Egypt and Lower Egypt respectively. Pediatric cases constituted 18.7% of the cases in Upper Egypt and 18.1% of the cases in Lower Egypt. Specific diagnosis was established in 71.3% and 67.7% of Upper and Lower Egypt cases respectively.

Conclusions: Patterns of uveitis differ according to the geographical area in Egypt.