182 research outputs found
Familial aggregation of maxillary lateral incisor agenesis
In spite of recent developments, data regarding the genes responsible for the less severe forms of hypodontia are still scarce and controversial. This study addressed the hypothesis that agenesis of maxillary lateral incisors (MLIA) is a distinct type of hypodontia, by evaluating its familial aggregation and the occurrence of other types of ageneses or microdontia in probands' relatives. Sixty-two probands with MLIA were identified, and information was collected on 142 first-degree relatives. Relative risk (RR) was calculated and compared by re-assessment of data previously published for the Swedish, Utah, and Israeli populations, for the same trait. A RR of 15 was obtained in the Portuguese, 16 in the Swedish, 12 in Utah, and 5 in the Israeli population. Our results support a significant familial aggregation of MLIA, show that MLIA almost never segregates with other forms of agenesis, and suggest that microdontia of maxillary lateral incisors is part of the same phenotype.The individuals who took part in this study are acknowledged. Carolina Lemos was the recipient of a PhD scholarship (FCT - SFRH/BD/17761/2004) and Teresa Pinho of a PhD scholarship from Instituto Superior de Ciencias da Saude Norte/CESPU. The other authors received no funding from any institution, department, or sponsor, other than salaries from the institutions with which they are affiliated
Fermion Representation Of The Rolling Tachyon Boundary Conformal Field Theory
A free fermion representation of the rolling tachyon boundary conformal field
theory is constructed. The representation is used to obtain an explicit,
compact, exact expression for the boundary state. We use the boundary state to
compute the disc and cylinder amplitudes for the half-S-brane.Comment: 27 page
Rayleigh Imaging of Graphene and Graphene Layers
We investigate graphene and graphene layers on different substrates by
monochromatic and white-light confocal Rayleigh scattering microscopy. The
image contrast depends sensitively on the dielectric properties of the sample
as well as the substrate geometry and can be described quantitatively using the
complex refractive index of bulk graphite. For few layers (<6) the
monochromatic contrast increases linearly with thickness: the samples behave as
a superposition of single sheets which act as independent two dimensional
electron gases. Thus, Rayleigh imaging is a general, simple and quick tool to
identify graphene layers, that is readily combined with Raman scattering, which
provides structural identification.Comment: 8 pages, 9 figure
Intramuscular Artesunate for Severe Malaria in African Children: A Multicenter Randomized Controlled Trial.
BACKGROUND: Current artesunate (ARS) regimens for severe malaria are complex. Once daily intramuscular (i.m.) injection for 3 d would be simpler and more appropriate for remote health facilities than the current WHO-recommended regimen of five intravenous (i.v.) or i.m. injections over 4 d. We compared both a three-dose i.m. and a three-dose i.v. parenteral ARS regimen with the standard five-dose regimen using a non-inferiority design (with non-inferiority margins of 10%). METHODS AND FINDINGS: This randomized controlled trial included children (0.5-10 y) with severe malaria at seven sites in five African countries to assess whether the efficacy of simplified three-dose regimens is non-inferior to a five-dose regimen. We randomly allocated 1,047 children to receive a total dose of 12 mg/kg ARS as either a control regimen of five i.m. injections of 2.4 mg/kg (at 0, 12, 24, 48, and 72 h) (n = 348) or three injections of 4 mg/kg (at 0, 24, and 48 h) either i.m. (n = 348) or i.v. (n = 351), both of which were the intervention arms. The primary endpoint was the proportion of children with ≥ 99% reduction in parasitemia at 24 h from admission values, measured by microscopists who were blinded to the group allocations. Primary analysis was performed on the per-protocol population, which was 96% of the intention-to-treat population. Secondary analyses included an analysis of host and parasite genotypes as risks for prolongation of parasite clearance kinetics, measured every 6 h, and a Kaplan-Meier analysis to compare parasite clearance kinetics between treatment groups. A post hoc analysis was performed for delayed anemia, defined as hemoglobin ≤ 7 g/dl 7 d or more after admission. The per-protocol population was 1,002 children (five-dose i.m.: n = 331; three-dose i.m.: n = 338; three-dose i.v.: n = 333); 139 participants were lost to follow-up. In the three-dose i.m. arm, 265/338 (78%) children had a ≥ 99% reduction in parasitemia at 24 h compared to 263/331 (79%) receiving the five-dose i.m. regimen, showing non-inferiority of the simplified three-dose regimen to the conventional five-dose regimen (95% CI -7, 5; p = 0.02). In the three-dose i.v. arm, 246/333 (74%) children had ≥ 99% reduction in parasitemia at 24 h; hence, non-inferiority of this regimen to the five-dose control regimen was not shown (95% CI -12, 1; p = 0.24). Delayed parasite clearance was associated with the N86YPfmdr1 genotype. In a post hoc analysis, 192/885 (22%) children developed delayed anemia, an adverse event associated with increased leukocyte counts. There was no observed difference in delayed anemia between treatment arms. A potential limitation of the study is its open-label design, although the primary outcome measures were assessed in a blinded manner. CONCLUSIONS: A simplified three-dose i.m. regimen for severe malaria in African children is non-inferior to the more complex WHO-recommended regimen. Parenteral ARS is associated with a risk of delayed anemia in African children. TRIAL REGISTRATION: Pan African Clinical Trials Registry PACTR201102000277177
Treatment responses in multidrug-resistant tuberculosis in Germany.
BACKGROUND: Excellent treatment outcomes have recently been reported for patients with multi/extensively drug-resistant tuberculosis (M/XDR-TB) in settings where optimal resources for individualised therapy are available. OBJECTIVE: To ascertain whether differences remain in treatment responses between patients with M/XDR-TB and those with non-M/XDR-TB. METHOD: Patients with TB were prospectively enrolled between March 2013 and March 2016 at five hospitals in Germany. Treatment was conducted following current guidelines and individualised on the basis of drug susceptibility testing. Two-month and 6-month sputum smear and sputum culture conversion rates were assessed. A clinical and radiological score were used to assess response to anti-tuberculosis treatment. RESULTS: Non-M/XDR-TB (n = 29) and M/XDR-TB (n = 46) patients showed similar rates of microbiological conversion: 2-month smear conversion rate, 90% vs. 78%; culture conversion rate, 67% vs. 61%; time to smear conversion, 19 days (IQR 10-32) vs. 31 days (IQR 14-56) (P = 0.066); time to culture conversion, 39 days (IQR 17-67) vs. 39 days (IQR 6-85) (P = 0.191). Both clinical and radiological scores decreased after the introduction of anti-tuberculosis treatment. CONCLUSION: There were no significant differences in scores between the two groups until 6 months of treatment. Under optimal clinical conditions, with the availability of novel diagnostics and a wide range of therapeutic options for individualised treatment, patients with M/XDR-TB achieved 6-month culture conversion rates that were compatible with those in patients with non-M/XDR-TB
Severe malaria in children leads to a significant impairment of transitory otoacoustic emissions--a prospective multicenter cohort study.
BACKGROUND: Severe malaria may influence inner ear function, although this possibility has not been examined prospectively. In a retrospective analysis, hearing impairment was found in 9 of 23 patients with cerebral malaria. An objective method to quickly evaluate the function of the inner ear are the otoacoustic emissions. Negative transient otoacoustic emissions are associated with a threshold shift of 20 dB and above. METHODS: This prospective multicenter study analyses otoacoustic emissions in patients with severe malaria up to the age of 10 years. In three study sites (Ghana, Gabon, Kenya) 144 patients with severe malaria and 108 control children were included. All malaria patients were treated with parental artesunate. RESULTS: In the control group, 92.6 % (n = 108, 95 % confidence interval 86.19-6.2 %) passed otoacoustic emission screening. In malaria patients, 58.5 % (n = 94, malaria vs controls p < 0.001, 95 % confidence interval 48.4-67.9 %) passed otoacoustic emission screening at the baseline measurement. The value increased to 65.2 % (n = 66, p < 0.001, 95 % confidence interval 53.1-75.5 %) at follow up 14-28 days after diagnosis of malaria. The study population was divided into severe non-cerebral malaria and severe malaria with neurological symptoms (cerebral malaria). Whereas otoacoustic emissions in severe malaria improved to a passing percentage of 72.9 % (n = 48, 95 % confidence interval 59-83.4 %) at follow-up, the patients with cerebral malaria showed a drop in the passing percentage to 33 % (n = 18) 3-7 days after diagnosis. This shows a significant impairment in the cerebral malaria group (p = 0.012 at days 3-7, 95 % confidence interval 16.3-56.3 %; p = 0.031 at day 14-28, 95 % confidence interval 24.5-66.3 %). CONCLUSION: The presented data show that 40 % of children have involvement of the inner ear early in severe malaria. In children, audiological screening after severe malaria infection is not currently recommended, but is worth investigating in larger studies
Developmental disturbances associated with agenesis of the permanent maxillary lateral incisor
The aim of this study was to characterise the intra and extra-oral phenotype associated with agenesis of the permanent maxillary lateral incisor. We compared three groups: (1) subjects with agenesis of one or both permanent maxillary lateral incisors (n=80); (2) first and second degree relatives of group 1 with no agenesis of the permanent maxillary lateral incisor and (3) subjects with no agenesis of the maxillary lateral incisor or family history of it (n=49). For each of the 201 subjects detailed clinical information was reviewed and panoramic radiographs were analysed. Considering only the sample with unilateral agenesis, microdontia of the contralateral permanent maxillary lateral incisor was significantly more frequent in group 1 (82.4%) than in group 2 (25%) and the control group (2%). This supports the theory that microdontia is a variable expression of the same developmental disturbance that causes tooth agenesis. The absence of third molars occurred more often in group 1 (36.2%) than in groups 2 and 3 (18.6% and 18.9% respectively), confirming that agenesis of third molars was markedly associated with the agenesis of the permanent maxillary lateral incisor. Agenesis of teeth other than third molars was not significantly different among subjects with agenesis of the permanent maxillary lateral incisor and their relatives. The frequencies of supernumerary teeth, permanent maxillary canine impaction, general health condition and minor anomalies were not significantly different between the three groups
- …