Effect of different solutions in reversing the damage caused by radiotherapy in dentin structure

Background

Previous studies have shown that radiotherapy of the head and neck region can cause direct changes in dental structure. This study evaluated the effect of different solutions on the dentin chemical composition and collagen structure of irradiated dentin.

Material and Methods

Sixty maxillary canines were distributed in 2 groups (n=30): non-irradiated and irradiated (radiotherapy: X-rays of 6 MV in 30 cycles of 2 Gy to 60 Gy). The teeth were sectioned, sanded, and polished to obtain 3x3x2 mm fragments, which were redistributed in 3 subgroups (n=10) according to the treatment employed: chlorhexidine 2% (CL), chitosan 0.2% (QT), and 0.5 M carbodiimide (EDC). The samples were analyzed in FTIR at time zero (T0-control) and after 1 (T1), 3 (T3), and 5 (T5) minutes of immersion in the tested solutions. The data for the areas of the carbonate (C), amide I (AI) bands, and the ratio between the areas of the amide III/proline and hydroxyproline (AIII/PH) bands were analyzed using ANOVA and Tukey test (α=5%).

Results

QT showed lower C values at T1, T3, and T5 (P<0.0001), presenting lower values when compared to CL and EDC subgroups (P<0.05). AI values at T3 and T5 were higher than T0-control and T1, independently of the radiotherapy and dentin treatment factors (P<0.05). At T0-control, the AIII/PH ratio was lower in the irradiated group (P<0.05), whereas the EDC treatment at T1, T3, and T5 and QT at T3 and T5 increased these values (P<0.05), making them similar to non-irradiated subgroups (P>0.05).

Conclusions

Radiotherapy changes the secondary structure of collagen, and EDC was able to restore collagen integrity after 1 minute of immersion, without changing dentin inorganic composition.

Key words:Radiotherapy, collagen, dentin, FTIR, chemical composition.

Ovarian damage from chemotherapy and current approaches to its protection

BACKGROUND

Anti-cancer therapy is often a cause of premature ovarian insufficiency and infertility since the ovarian follicle reserve is extremely sensitive to the effects of chemotherapy and radiotherapy. While oocyte, embryo and ovarian cortex cryopreservation can help some women with cancer-induced infertility achieve pregnancy, the development of effective methods to protect ovarian function during chemotherapy would be a significant advantage.

OBJECTIVE AND RATIONALE

This paper critically discusses the different damaging effects of the most common chemotherapeutic compounds on the ovary, in particular, the ovarian follicles and the molecular pathways that lead to that damage. The mechanisms through which fertility-protective agents might prevent chemotherapy drug-induced follicle loss are then reviewed.

SEARCH METHODS

Articles published in English were searched on PubMed up to March 2019 using the following terms: ovary, fertility preservation, chemotherapy, follicle death, adjuvant therapy, cyclophosphamide, cisplatin, doxorubicin. Inclusion and exclusion criteria were applied to the analysis of the protective agents.

OUTCOMES

Recent studies reveal how chemotherapeutic drugs can affect the different cellular components of the ovary, causing rapid depletion of the ovarian follicular reserve. The three most commonly used drugs, cyclophosphamide, cisplatin and doxorubicin, cause premature ovarian insufficiency by inducing death and/or accelerated activation of primordial follicles and increased atresia of growing follicles. They also cause an increase in damage to blood vessels and the stromal compartment and increment inflammation. In the past 20 years, many compounds have been investigated as potential protective agents to counteract these adverse effects. The interactions of recently described fertility-protective agents with these damage pathways are discussed.

WIDER IMPLICATIONS

Understanding the mechanisms underlying the action of chemotherapy compounds on the various components of the ovary is essential for the development of efficient and targeted pharmacological therapies that could protect and prolong female fertility. While there are increasing preclinical investigations of potential fertility preserving adjuvants, there remains a lack of approaches that are being developed and tested clinically.

A204 ANALYSIS AND CHARACTERIZATION OF THE EXCRETED AND SECRETED PRODUCTS OF PARASITIC HELMINTHS AS IMMUNOMODULATORS OF INFLAMMATORY BOWEL DISEASE

Background

Parasitic helminths are known for their exceptional ability to modulate the host immune response in order to favour their survival. The excretory/secretory products (ESP), from Trichuris and Ascaris species are of keen interest for inflammatory bowel disease (IBD). Crohn’s disease and ulcerative colitis patients have benefitted from the administration of ova of T. suis in clinical trials, whereby symptoms were remediated through the ingestion of parasite ova, which subsequently hatch in the intestine. Our previous work has demonstrated the ability of T. suis ESP to downregulate secretion of inflammatory cytokines (TNF-α, IL-12) and increase the secretion of anti-inflammatory cytokines (IL-10) in murine bone marrow-derived macrophages.

Aims

This research aims to unveil the mechanisms of immune modulation by parasitic helminths in the context of IBD. We aim to characterize the cellular response in vitro, as well as the systemic response in vivo, in order to better characterize the scope of immune modulation that occurs with treatment.

Methods

Human peripheral blood mononuclear cell (PBMC) monocytes were purified and treated with helminth-derived products. The products were removed, and fresh media was added containing lipopolysaccharide (LPS) to stimulate cells. Supernatants were collected for cytokine analysis and cells were lysed and frozen.

Mice were given 3% DSS or regular water for five days, and subsequently administered treatment with helminth-derived products, or a PBS control, once daily by intraperitoneal injection for 3–4 days. Weights were measured daily. On day 9 mice were sacrificed, colons lengths were measured, and spleens were collected for further analysis.

Results

We found that human PBMC monocytes treated with the ESP from T. suis and A. suum had decreased secretion of inflammatory cytokines (TNFα) and increased secretion of anti-inflammatory cytokines (IL-10).

Additionally, we found that heminth products from A. suum had the ability to reverse the symptoms of weight loss and colon shrinking in DSS-mice compared to the control. Specifically, mice with DSS-induced colitis treated with metabolites increased their weight more than the PBS control (P &lt; 0.0001) and had a longer colon compared to the PBS control (P &lt; 0.001).

Conclusions

Taken together, these data generate an interest for intestinal helminth products as immunomodulators regarding treatment for patients suffering from inflammatory bowel disease (IBD).

Funding Agencies

NSERC and FRQNT

A205 NON-POLAR HELMINTH-DERIVED METABOLITES MODULATES INNATE IMMUNE CELL RESPONSE AND PROTECTS MICE FROM EXPERIMENTAL COLITIS

Background

The hygiene hypothesis postulates that the lack of exposure to helminth parasites would contribute to the development of the auto-inflammatory disease. There has been a significant increase in patients with inflammatory bowel disease (IBD) in North America. The previous study showed that infection with gastrointestinal helminth parasitedownregulated inflammatory pathways in several gut inflammation models. Given the known risks of live helminth infection, the therapy should direct towards helminth-derived properties.

Aims

To determine if helminth-derived metabolites treated mice are protected from DSS-induced colitis.

Methods

Preliminary, our screening reveled that non-polar fractions of 4 distinct helminth modulate LPS-induced inflammatory cytokines in vitro. 3% DSS or water was given to C57BL/6 mice for 5 days, followed by 4 days of a recovery period. The mice were treated intraperitoneal injection with non-polar helminth-derived metabolites (NPHM) on days 5, 6, and 7. Inflammation was assessed by disease activity,histopathology and cytokine mRNA expression in colons. The effect of NPHM on neutrophil chemotaxis was assess inin vitroand in vivo.

Results

The disease activity and histopathology score were significantly lower in DSS treated mice received NPHM. Also, NPHM treatment resulted in a decrease of an inflammatory cytokine such as TNF-α mRNA expression in the colon of mice with DSS-induced colitis. Mechanistically, NPHM reduced neutrophil chemotaxis.

Conclusions

NPHM treatment protects against DSS-induced colitis and modulate neutrophil response, which supports helminth therapy for IBD.

Funding Agencies

Supported by Hashimoto Municipal Hospital scholarship to TA and an NSERC Discovery grant to Fernando Lopes.

Genome-enable prediction for health traits using high-density SNP panel in US Holstein cattle

The objective of this study was to compare accuracies of different Bayesian regression models in predicting molecular breeding values for health traits in Holstein cattle. The dataset was composed of 2505 records reporting the occurrence of retained fetal membranes (RFM), metritis (MET), mastitis (MAST), displaced abomasum (DA), lameness (LS), clinical endometritis (CE), respiratory disease (RD), dystocia (DYST) and subclinical ketosis (SCK) in Holstein cows, collected between 2012 and 2014 in 16 dairies located across the US. Cows were genotyped with the Illumina BovineHD (HD, 777K). The quality controls for SNP genotypes were HWE P‐value of at least 1 × 10⁻¹⁰; MAF greater than 0.01 and call rate greater than 0.95. The fimpute program was used for imputation of missing SNP markers. The effect of each SNP was estimated using the Bayesian Ridge Regression (BRR), Bayes A, Bayes B and Bayes Cπ methods. The prediction quality was assessed by the area under the curve, the prediction mean square error and the correlation between genomic breeding value and the observed phenotype, using a leave‐one‐out cross‐validation technique that avoids iterative cross‐validation. The highest accuracies of predictions achieved were: RFM [Bayes B (0.34)], MET [BRR (0.36)], MAST [Bayes B (0.55), DA [Bayes Cπ (0.26)], LS [Bayes A (0.12)], CE [Bayes A (0.32)], RD [Bayes Cπ (0.23)], DYST [Bayes A (0.35)] and SCK [Bayes Cπ (0.38)] models. Except for DA, LS and RD, the predictive abilities were similar between the methods. A strong relationship between the predictive ability and the heritability of the trait was observed, where traits with higher heritability achieved higher accuracy and lower bias when compared with those with low heritability. Overall, it has been shown that a high‐density SNP panel can be used successfully to predict genomic breeding values of health traits in Holstein cattle and that the model of choice will depend mostly on the genetic architecture of the trait.

Refining the phenotype associated with biallelic DNAJC21 mutations

Inherited bone marrow failure syndromes (IBMFS) are caused by mutations in genes involved in genomic stability. Although they may be recognized by the association of typical clinical features, variable penetrance and expressivity are common, and clinical diagnosis is often challenging. DNAJC21, which is involved in ribosome biogenesis, was recently linked to bone marrow failure. However, the specific phenotype and natural history remain to be defined. We correlate molecular data, phenotype, and clinical history of 5 unreported affected children and all individuals reported in the literature. All patients present features consistent with IBMFS: bone marrow failure, growth retardation, failure to thrive, developmental delay, recurrent infections, and skin, teeth or hair abnormalities. Additional features present in some individuals include retinal abnormalities, pancreatic insufficiency, liver cirrhosis, skeletal abnormalities, congenital hip dysplasia, joint hypermobility, and cryptorchidism. We suggest that DNAJC21-related diseases constitute a distinct IBMFS, with features overlapping Shwachman-Diamond syndrome and Dyskeratosis congenita, and additional characteristics that are specific to DNAJC21 mutations. The full phenotypic spectrum, natural history, and optimal management will require more reports. Considering the aplastic anemia, the possible increased risk for leukemia, and the multisystemic features, we provide a checklist for clinical evaluation at diagnosis and regular follow-up.

Triggering immunological memory against the tapeworm Hymenolepis diminuta to protect against colitis

Infection with parasitic helminths can ameliorate the severity of concomitant inflammatory disease. To use the tapeworm, Hymenolepis diminuta, and to extend this concept by assessing whether triggering a memory response against the worm inhibits dinitrobenzene sulphonic acid (DNBS)-induced colitis in Balb/c mice. Initial studies revealed that oral infection with 1, 3 or 5 H. diminuta cysticercoids 8 days before intrarectal administration of DNBS (3 mg) resulted in less severe inflammation and that infected mice displayed an increased propensity for T helper-2 immunity. A 1 mg dose of a PBS-soluble extract of the worm (HdAg) delivered intraperitoneally concomitant with DNBS was anticolitic as determined by macroscopic and histological disease scores 72 hour post-DNBS. Mice infected 28 days previously had a memory response as determined by HdAg-evoked increases in interleukin (IL)-4 and IL-10 from in vitro stimulated splenocytes and serum anti-H. diminuta IgG. Moreover, mice infected with 5 H. diminuta 28 days previously were protected from DNBS-induced colitis by secondary infection or 100 μg HdAg (ip.) at the time of DNBS treatment. An additional approach to managing inflammatory disease could be infection with H. diminuta followed by eliciting antiworm recall responses.

Power to Health Reporters: Health Literacy as a Tool to Avoid Pressures from News Sources

The second biggest Legionnaires’ disease outbreak worldwide occurred in Portugal in 2014. It was classified by the WHO as a “great public health emergency,” and it was subject to a unique media coverage in Portugal. The media coverage of this outbreak lasted for 2 weeks, which is not very common in similar cases, and it was characterized by the control of information by official sources. These were put together in a joint task force that disseminated all information. Nonetheless, they did not generate a hegemonic discourse which is usually characteristic of power elites. That happened mostly due to the promotion of health and risk literacy. Through infographics, descriptive maps, and questions and answers, the media were able to generate an alternative discourse to that of official sources. That was the basis of a unique media coverage.

O erro médico na imprensa portuguesa: quando os pacientes fazem parte da notícia

Esta investigação aborda a qualidade da produção noticiosa sobre o erro médico, como um fator essencial na construção do conhecimento público sobre o tema, com o objetivo de compreender que características definem tal produção e até que ponto poderão ser explicadas pela periodicidade e orientação editorial dos jornais; que conceito de erro médico é veiculado pela produção noticiosa sobre o tema; e quais são os protagonistas no discurso jornalístico sobre o erro médico. Foram analisadas as edições de três jornais portugueses, de 2008 a 2011, resultando num corpus de 266 (4,2%) artigos, que foram classificados de acordo com as seguintes variáveis: as fontes de informação citadas (o seu estatuto e especialidade, no caso dos médicos); os temas que são tratados; as características de enquadramento da informação publicada (tom, género jornalístico; e a presença e número de fontes de informação). Pela análise de conteúdo quantitativa, apurou-se que esse tema está em crescimento, essencialmente com notícias de tom negativo e fontes de informação habitualmente identificadas. Não há evidência para afirmar que a periodicidade e a orientação editorial expliquem as variações dessas características, a não ser relativamente ao número de fontes citadas. Vigoram as notícias centradas nos resultados dos erros (mortes ou lesões), provocados por "erros de omissão" e por "erros de comissão", envolvendo uma diversidade de protagonistas: são, tal como acontece na informação sobre saúde em geral, fontes oficiais e especializadas do campo da saúde. Destacam-se os médicos e os juristas e é dado relevo aos pacientes.