Spectrophotometric Analysis of Coronal Discoloration In Vitro Induced by Bioceramic Cements

The aim of this study was to evaluate and quantify, in vitro, the extent of coronal discoloration induced by bioceramic materials over time. In total, 44 human monoradicular teeth were divided into four groups (n = 11), according to the applied material: Negative control (NC); White MTA ProRoot^® (WMTAP); Biodentine^™ (BD); and TotalFill^® BC RRM^™ Putty (TF). Teeth were immersed in saline solution and incubated at 37 °C; the following periods of time were defined: before incubation: [t0]-without bioceramic material, t1-immediately after the bioceramic material placement; after incubation: t24h-24 h, t7d-7 days, and 30d-30 days. Descriptive and inferential statistical analysis were performed. Cochran's Q test was used to evaluate coronal discoloration across the different groups, while the Kruskal-Wallis test was employed to determine differences in discoloration among the groups at each time interval. Additionally, the Friedman test was applied to analyze the variations in discoloration within each group over time. A significance level of 5% was set. All experimental groups revealed coronal discoloration over time: NC (p = 0.001), WMTAP (p < 0.001), BD (p = 0.001), and TF (p = 0.006). No significant differences were observed between groups for each time interval (p > 0.05). The WMTAP group varied the most considering the intervals [t0-t1] and [t24h-t7d] (p = 0.037) compared to the remaining experimental groups.

Copper-induced Haemolytic Anaemia

Acute copper toxicity is uncommon in Western countries and is often the result of accidental consumption or a suicide attempt. We report the case of a 65-year-old man presenting to the accident and emergency department after a suicide attempt with ingestion of Bordeaux mixture, ibuprofen, acetaminophen and bleach. Primary evaluation showed caustic oesophagitis, toxic hepatitis and acute renal injury, which were treated with supportive care. During admission, he developed a non-immune haemolytic anaemia associated with high levels of copper in urine and blood. Chelation treatment with penicillamine was started and evolution was favourable after 1 month of treatment. Copper poisoning can be lethal. Prompt diagnosis and treatment are key for a favourable prognosis.

LEARNING POINTS

Acute copper intoxication is rare and early clinical suspicion and diagnosis are essential to reduce mortality.The diagnosis of copper poisoning should be based on clinical presentation and measurement of urine and blood copper levels in addition to serum ceruloplasmin levels.Treatment includes reduction of absorption, supportive measures, management of complications and chelation therapy.

A therapeutic antibody targeting osteoprotegerin attenuates severe experimental pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a rare but fatal disease. Current treatments increase life expectancy but have limited impact on the progressive pulmonary vascular remodelling that drives PAH. Osteoprotegerin (OPG) is increased within serum and lesions of patients with idiopathic PAH and is a mitogen and migratory stimulus for pulmonary artery smooth muscle cells (PASMCs). Here, we report that the pro-proliferative and migratory phenotype in PASMCs stimulated with OPG is mediated via the Fas receptor and that treatment with a human antibody targeting OPG can attenuate pulmonary vascular remodelling associated with PAH in multiple rodent models of early and late treatment. We also demonstrate that the therapeutic efficacy of the anti-OPG antibody approach in the presence of standard of care vasodilator therapy is mediated by a reduction in pulmonary vascular remodelling. Targeting OPG with a therapeutic antibody is a potential treatment strategy in PAH.

Pulmonary arterial hypertension (PAH) is characterised by progressive pulmonary vascular remodelling. Here, Arnold et al. develop a therapeutic antibody targeting osteoprotegerin and find it attenuates pulmonary vascular remodelling in multiple rodent models of PAH, alone or in combination with standard of care vasodilator therapy.

Biochemical conversion of sugarcane straw hemicellulosic hydrolyzate supplemented with co-substrates for xylitol production

Biotechnological production of xylitol is an attractive route to add value to a sugarcane biorefinery, through utilization of the hemicellulosic fraction of sugarcane straw, whose availability is increasing in Brazil. Herein, supplementation of the sugarcane straw hemicellulosic hydrolyzate (xylose 57gL(-1)) with maltose, sucrose, cellobiose or glycerol was proposed, and their effect as co-substrates on xylitol production by Candida guilliermondii FTI 20037 was studied. Sucrose (10gL(-1)) and glycerol (0.7gL(-1)) supplementation led to significant increase of 8.88% and 6.86% on xylose uptake rate (1.11gL(-1)h(-1) and 1.09gL(-1)), respectively, but only with sucrose, significant increments of 12.88% and 8.69% on final xylitol concentration (36.11gL(-1)) and volumetric productivity (0.75gL(-1)h(-1)), respectively, were achieved. Based on these results, utilization of complex sources of sucrose, derived from agro-industries, as nutritional supplementation for xylitol production can be proposed as a strategy for improving the yeast performance and reducing the cost of this bioprocess by replacing more expensive nutrients.

Association between NOx exposure and deaths caused by respiratory diseases in a medium-sized Brazilian city

Exposure to nitrogen oxides (NOx) emitted by burning fossil fuels has been associated with respiratory diseases. We aimed to estimate the effects of NOx exposure on mortality owing to respiratory diseases in residents of Taubaté, São Paulo, Brazil, of all ages and both sexes. This time-series ecological study from August 1, 2011 to July 31, 2012 used information on deaths caused by respiratory diseases obtained from the Health Department of Taubaté. Estimated daily levels of pollutants (NOx, particulate matter, ozone, carbon monoxide) were obtained from the Centro de Previsão de Tempo e Estudos Climáticos Coupled Aerosol and Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System. These environmental variables were used to adjust the multipollutant model for apparent temperature. To estimate association between hospitalizations owing to asthma and air pollutants, generalized additive Poisson regression models were developed, with lags as much as 5 days. There were 385 deaths with a daily mean (±SD) of 1.05±1.03 (range: 0-5). Exposure to NOx was significantly associated with mortality owing to respiratory diseases: relative risk (RR)=1.035 (95% confidence interval [CI]: 1.008-1.063) for lag 2, RR=1.064 (95%CI: 1.017-1.112) lag 3, RR=1.055 (95%CI: 1.025-1.085) lag 4, and RR=1.042 (95%CI: 1.010-1.076) lag 5. A 3 µg/m³ reduction in NOx concentration resulted in a decrease of 10-18 percentage points in risk of death caused by respiratory diseases. Even at NOx concentrations below the acceptable standard, there is association with deaths caused by respiratory diseases.

Regional trends in fertility and mortality in Brazil

Abstract Questions asked in the 1970 Brazilian census allow the application of fertility and childhood mortality techniques developed by W. Brass. Using some propositions based on fertility estimates from the 1970 census data it was possible to extend the analysis to the 1940, 1950 and 1960 censuses. Estimates are also provided for ten Brazilian regions, for 1940, 1950 and 1970. These estimates show a slight decrease in the fertility level for the country as a whole, but two different trends at regional levels. Between 1940-50 and 1960-70 the poorer regions experienced constant or increasing fertility levels while developed regions experienced declining ones, with only one exception. The mortality estimates indicate a consistent decline in the mortality level of all regions, but also a divergent trend between poor and developed regions, in life expectancies at birth. This work is a summarized version of Chapters II, III and IV of my Ph.D. thesis written under the supervision of Professor D. V. Glass and Mr J. Hobcraft at the University of London. I am most grateful to my supervisors as well as to Professor W. Brass for valuable comments on several aspects of the thesis. While carrying out this study, the author was supported by grants from the Federal University of Minas Gerais, Brazil, and the Ford Foundation.

DNA vaccines: a rational design against parasitic diseases

Parasitic diseases are one of the most devastating causes of morbidity and mortality worldwide. Although immunization against these infections would be an ideal solution, the development of effective vaccines has been hampered by specific challenges posed by parasitic pathogens. Plasmid-based DNA vaccines may prove to be promising immunization tools in this area because vectors can be designed to integrate several antigens from different stages of the parasite life cycle or different subspecies; vaccines, formulations and immunization protocols can be tuned to match the immune response that offers protective immunity; and DNA vaccination is an affordable platform for developing countries. Partial and full protective immunity have been reported following DNA vaccination against the most significant parasitic diseases in the world.

Bringing DNA vaccines closer to commercial use

Progress in the application of DNA vaccines as an immunization protocol is evident from the increasing number of such vaccines under evaluation in clinical trials and by the recent approval of several DNA vaccine products for veterinary applications. DNA vaccine technology offers important therapeutic and commercial advantages compared with conventional approaches, including the opportunity to target pathogens characterized by significant genetic diversity using a safe immunization platform, and the ability to use a simple, rapid and well-characterized production method. However, further optimization of DNA vaccine technology through the use of improved constructs, delivery systems and immunization protocols is necessary to clinically achieve the promising results that have been demonstrated in preclinical models.

Nine novel mutations in NR0B1 (DAX1) causing adrenal hypoplasia congenita

X-linked adrenal hypoplasia congenita (AHC) is caused by mutations in the NR0B1 gene. This gene encodes an orphan member of the nuclear receptor superfamily, DAX1. Ongoing efforts in our laboratory have identified nine novel NR0B1 mutations in X-linked AHC patients (Y81X, 343delG, 457delT, 629delG, L295P, 926-927delTG, 1130delA, 1141-1155del15, and E428X). Two additional families segregate previously identified NR0B1 mutations (501delA and R425T). Sequence analysis of the mitochondrial D-loop indicates that the 501delA family is unrelated through matrilineal descent to our previously analyzed 501delA family.

In vitro and in vivo responses to short-term recombinant human insulin-like growth factor-1 (IGF-I) in a severely growth-retarded girl with ring chromosome 15 and deletion of a single allele for the type 1 IGF receptor gene

OBJECTIVES

Patients with single allele defects in the gene encoding the type 1 IGF receptor have been reported to have growth failure, but fibroblasts from affected patients have not exhibited insensitivity to the effects of IGF-I in vitro. The in vitro and in vivo responses to short-term recombinant human IGF-I (rhIGF-I) in a severely growth-retarded girl with ring chromosome 15 and deletion of a single allele for the type 1 IGF receptor gene have been investigated.

DESIGN AND PATIENT

The child exhibited prenatal and severe post-natal growth failure, and delayed psychomotor development. Southern blotting revealed a 50% reduction in IGF-I receptor DNA, and in an RNase protection assay (RPA), a quantitatively similar reduction in steady-state mRNA for type 1 IGF receptor. rhIGF-I was administered in graded doses of 40, 60 and 80 microg/kg twice daily by subcutaneous injection for periods of 2-2.5 days each.

RESULTS

During rhIGF-I treatment, mean urinary nitrogen excretion was unchanged and urinary calcium rose to 60% greater than in the pre-treatment period. rhIGF-I injections produced only a modest decrease in indices of GH secretion, assessed by frequent (every 20 min) sampling over periods of 12 h. There was no significant difference between the mean GH concentrations during rhIGF-I treatment (5.32 +/- 6.2 mU/l) compared with that before rhIGF-I treatment (8.46 +/- 10.2 mU/l). Mean IGFBP-3-values were increased (4.5 mg/l before vs. 5.4 mg/l during rhIGF-I). TSH values after injection of TRH were not significantly reduced by IGF-I (mean of all values, 18.6 mU/l vs. 15.5 mU/l during rhIGF-I treatment). In vitro binding of radiolabelled IGF-I to the patient's fibroblasts was less than that bound by control fibroblasts (patient, 0.69% binding by 248 000 cells, vs. 1.41% binding by 260 000 fibroblasts from an age-matched control). However, the patient's fibroblasts exhibited a growth response in vitro to the addition of IGF-I in a fashion similar to that of control fibroblasts.

CONCLUSIONS

These studies show evidence in each of the indices examined of in vivo resistance to IGF-I and suggest that the growth retardation observed in such patients may be the direct result of the absence of one of the alleles encoding the type 1 IGF receptor.