Protective effects of the angiotensin type 1 receptor antagonist losartan in infection-induced and arthritis-associated alveolar bone loss.

BACKGROUND AND OBJECTIVE: The angiotensin type 1 (AT1) receptor has been implicated in the pathogenesis of inflammatory bone disorders. This study aimed to investigate the effect of an AT1 receptor antagonist in infection-induced and arthritis-associated alveolar bone loss in mice. MATERIAL AND METHODS: Mice were subjected to Aggregatibacter actinomycetemcomitans oral infection or antigen-induced arthritis and treated daily with 10 mg/kg of the prototype AT1 antagonist, losartan. Treatment was conducted for 30 d in the infectious condition and for 17 d and 11 d in the preventive or therapeutic regimens in the arthritic model, respectively. The mice were then killed, and the maxillae, serum and knee joints were collected for histomorphometric and immunoenzymatic assays. In vitro osteoclast assays were performed using RAW 264.7 cells stimulated with A. actinomycetemcomitans lipopolysacharide (LPS). RESULTS: Arthritis and A. actinomycetemcomitans infection triggered significant alveolar bone loss in mice and increased the levels of myeloperoxidase and of TRAP(+) osteoclasts in periodontal tissues. Losartan abolished such a phenotype, as well as the arthritis joint inflammation. Both arthritis and A. actinomycetemcomitans conditions were associated with the release of tumor necrosis factor alpha (TNF-α), interferon-gamma, interleukin-17 and chemokine (C-X-C motif) ligand 1 and an increased RANKL/osteoprotegerin ratio in periodontal tissues, but such expression decreased after losartan treatment, except for TNF-α. The therapeutic approach was as beneficial as the preventive one. In vitro, losartan prevented LPS-induced osteoclast differentiation and activity. CONCLUSION: The blockade of AT1 receptor exerts anti-inflammatory and anti-osteoclastic effects, thus protecting periodontal tissues in distinct pathophysiological conditions of alveolar bone loss.

High prevalence of asymptomatic Leishmania spp. infection among liver transplant recipients and donors from an endemic area of Brazil.

Visceral leishmaniasis is an uncommon disease in transplant recipients; however, if left untreated, the mortality can be high. If an organ donor or recipient is known to be an asymptomatic Leishmania spp. carrier,monitoring is advised. This study proposes to assess the prevalence of asymptomatic Leishmania spp.infection in liver transplant donors and recipients from an endemic area. A total of 50 liver recipients and 17 liver donors were evaluated by direct parasite search, indirect fluorescent antibody test (IFAT), anti-Leishmania rK39 rapid test and Leishmania spp.DNA detection by polymerase chain reaction (PCR).Leishmania spp. amastigotes were not observed in liver or spleen tissues. Of the 67 serum samples, IFAT was reactive in 1.5% and indeterminate for 17.9%, and the anti-Leishmania rK39 rapid test was negative for all samples. The PCR test was positive for 7.5%, 8.9%, and 5.9% of blood, liver and spleen samples, respectively(accounting for 23.5% of the donors and 8% of the recipients). Leishmania infantum-specific PCR confirmed all positive samples. In conclusion, a high prevalence of asymptomatic L. infantum was observed in donors and recipients from an endemic area, and PCR was the most sensitive method for screening these individuals.

Subchronic effects of dipyrone on the fish species Rhamdia quelen.

The use of the non-steroidal anti-inflammatory drugs such as dipyrone is so widespread that this drug and its metabolites have been detected in effluents and surface water. This study aimed to evaluate the potential toxic effects of dipyrone on the aquatic environment, using a native fish species, Rhamdia quelen. Fish were exposed to three concentrations of dipyrone, 0.5, 5 and 50 µg/L, in the water for 15 days, and hematological, biochemical, genetic and morphological biomarkers were evaluated. The glutathione S-transferase activity decreased in the highest concentration in relation to the control group. In addition, hematocrit, red blood cells and thrombocyte counts were decreased in all three exposed groups in relation to the control group. The comet assay showed DNA damage at the lowest concentration of dipyrone and significant kidney damage. Those results suggest that a constant exposure of aquatic organisms to dipyrone presents potential toxic effects.

Oral health-related quality of life in caregivers of individuals with Cerebral Palsy: a case-control study.

AIM: The object of this study is to evaluate the oral health-related quality of life (OHRQoL) of caregivers of individuals with Cerebral Palsy (CP). METHODS: Ninety-eight caregivers of individuals with CP (SG) and 196 caregivers of individuals without special needs (CG) completed the reduced version of the Oral Health Impact Profile (OHIP-14). In addition, a questionnaire with demographic and socioeconomic questions was used. Groups were matched according to gender, schooling and family income. Fisher's exact tests, Chi square and Mann-Whitney, and bi/multivariate logistic regression were used (p < 0.05). RESULTS: The impact on OHRQoL was similar for SG and CG (OHIP-14 total score). For SG, the high negative impact was in the following OHIP domains: "Functional limitation", "Physical disability", "Psychological incapacity" and "Disadvantages". For SG, a higher number of caregivers was single, unemployed, received government financial aid. There was a statistically significant association between the number of children a caregiver has and a negative impact on OHRQoL. CONCLUSIONS: Being a caregiver of children with or without CP had a negative impact of similar magnitude on ORHQoL. The negative impact on OHRQoL of caregivers of children with CP was associated with having a high number of children; the higher the number of children, the greater the negative impact on their OHRQoL.

Assessment of the neutron radiation field with activation foils and intermittent irradiations around a PETtrace biomedical cyclotron.

This work aimed at assessing the neutron radiation field with activation foils around of the PETtrace biomedical cyclotron. Activation foils of gold, gold covered with cadmium, indium and nickel was used to evaluate the thermal, epithermal and fast neutron contributions, respectively. The irradiations of the activation foils were performed using the intermittent irradiation method to conciliate the measurements with the routine 18F production. The evaluated points showed the contributions of the thermal, epithermal and fast neutrons due to interaction with the vault room, cyclotron accelerator and main cyclotron components.

Effects of phenanthrene on different levels of biological organization in larvae of the sediment-dwelling invertebrate Chironomus sancticaroli (Diptera: Chironomidae).

The hydrocarbon phenanthrene is an organic compound commonly found in the environment. In aquatic ecosystems, it is highly toxic to organisms, although little is known about its effects on sediment-dwelling organisms. The purpose of this study was to evaluate phenanthrene effects on biochemical, histological, and ontogenetic levels in larvae of the sediment-dwelling invertebrate Chironomus sancticaroli at acute and chronic exposure. Lethal concentrations were estimated and toxicity (acute-96 h and chronic- 8 d) tests were performed at phenanthrene concentrations from 0.12 to 1.2 mg L-1. At acute and chronic exposure, we evaluated acetylcholinesterase (AChE), alpha esterase (EST-α), and beta esterase (EST-ß) activities as well as histological alterations. In the assays with chronic exposure, effects on larval development were estimated using antennae length (instar estimative) and body length (growth estimative). The EST-α showed a significantly increased activity after 48 h at acute exposure to high concentrations of phenanthrene, while EST-ß activity was increased after 48 and 72 h at acute exposure at higher concentrations and at 0.12 mg L-1 at chronic exposure. At acute exposure, the midgut showed alterations such as brush border disruption, gastric caeca regression, and lumen area reduction; the fat body showed nuclear alteration in the trophocytes, while the Malpighian tubules showed brush border reduction and the salivary glands were subject to cytoplasm vacuolation. At chronic exposure, the same alterations were observed, in addition to vacuolar coalescence in the trophocytes of the fat body. Regarding larval development, a reduction of body length was observed with increasing phenanthrene concentrations. Similarly, molting was delayed; in the control group, all larvae were in the fourth instar, while at higher phenanthrene concentrations, larvae were predominantly in the third instar. Phenanthrene had toxic effects on this chironomid, indicating risks for natural populations.

Effectiveness and safety of foam sclerotherapy with 5% ethanolamine oleate in the treatment of low-flow venous malformations in the head and neck region: a case series.

The aim of this study was to evaluate the effectiveness and safety of 5% ethanolamine oleate (EO) foam in the treatment of low-flow venous malformations in the head and neck region. Seventeen consecutive patients (six male, 11 female) and 34 low-flow venous malformations were enrolled. The vascular anomalies ranged between 20mm and 80mm in size. The typical clinical indication was a swelling (88.2%) with a purple colour (85.3%); the most frequent location was the tongue (23.5%). Ethanolamine oleate foam was produced via the Tessari method and applied at 10mg per 1cm to the vascular anomalies. This process resulted in the highest clinical healing score in 64.7% of cases, and half of the patients reported a high level of satisfaction (score >9). In the majority of cases (88.2%), the patients reported that the pain immediately postoperative was mild or moderate. There were direct relationships between vascular anomaly size and the volume of EO applied, the number of sessions, and healing (P<0.05). No recurrence was observed during 6 months of follow-up. This case series showed the effectiveness and safety of 5% EO foam for the treatment of venous malformations in the head and neck region.

Absorbed doses on patients undergoing tomographic exams for pre-surgery planning of dental implants.

The thermoluminescent (TL) dosimetry was used to measure entrance skin absorbed doses at anatomical points close to critical organs of patients undergoing tomographic techniques as part of a pre-surgery planning for dental implants. The dosimetric procedure was applied in 19 patients, and absorbed doses could be measured with a combined uncertainty down to 14%. Results showed that patient doses may be increased by a factor of 20 in the helical computed tomography compared to panoramic and spiral conventional tomographic exams.

Verification of absorbed dose rates in reference beta radiation fields: Measurements with an extrapolation chamber and radiochromic film.

Beta Secondary Standard 2 (BSS 2) provides beta radiation fields with certified values of absorbed dose to tissue and the derived operational radiation protection quantities. As part of the quality assurance, the reliability of the CDTN BSS2 system was verified through measurements in the 90Sr/90Y and 85Kr beta radiation fields. Absorbed dose rates and their angular variation were measured with a 23392 model PTW extrapolation chamber and with Gafchromic radiochromic films on a PMMA slab phantom. The feasibility of using both methods was analyzed.

Neutron spectra due (13)N production in a PET cyclotron.

Monte Carlo and experimental methods have been used to characterize the neutron radiation field around PET (Positron Emission Tomography) cyclotrons. In this work, the Monte Carlo code MCNPX was used to estimate the neutron spectra, the neutron fluence rates and the ambient dose equivalent (H*(10)) in seven locations around a PET cyclotron during (13)N production. In order to validate these calculations, H*(10) was measured in three sites and were compared with the calculated doses. All the spectra have two peaks, one above 0.1MeV due to the evaporation neutrons and another in the thermal region due to the room-return effects. Despite the relatively large difference between the measured and calculated H*(10) for one point, the agreement was considered good, compared with that obtained for (18)F production in a previous work.

Dentin-induced in vivo inflammatory response and in vitro activation of murine macrophages.

The activation of inflammatory cells and consequent release of mediators play an important role in the resorption of mineralized tissues. In the present study, we examined the ability of dentin extracts to induce inflammatory cell recruitment and activation. We showed here that dentin extracts triggered an intense cell migration and progressive cell maturation, in a time- and dose-dependent manner. Expression of interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), nitric oxide (NO), and hydrogen peroxide (H(2)O(2)) was also up-regulated by dentin extracts. These results show that inflammatory events can be elicited in response to dentin, which may suggest a possible involvement of dentin molecules in the inflammatory events, coupled with their release at the root resorption sites.

Organ equivalent doses of patients undergoing chest computed tomography: measurements with TL dosimeters in an anthropomorphic phantom.

Dose reduction in patients undergoing computed tomography (CT) examinations has become a concern in many countries. CT dosimetric quantities were defined aiming optimization of CT procedures, organ absorbed doses and effective doses have been calculated for radiation risk assessments in patients. In this work, an experimental methodology was established for measuring organ doses with thermoluminescent (TL) dosimeters in an anthropomorphic phantom for routine CT chest examinations. Results may be useful for validating computational software used for CT dose calculations.

Use of the MCNPX to calculate the neutron spectra around the GE-PETtrace 8 cyclotron of the CDTN/CNEN, Brazil.

The Monte Carlo code MCNPX was used to calculate the neutron spectra in 4 points around the targets of the CDTN/CNEN cyclotron, Belo Horizonte, Brazil, during the production of the (18)FDG. Simulated data were compared with experimental data obtained with a Bonner multisphere spectrometry system (BSS) using TLD-600 and TLD-700 and the unfolding codes BUNKIUT, BUMS and NSDUAZ. In general, simulated spectra disagreed with those obtained by experimental means by a factor as high as 14. Measurements performed with a doserate meter in other 3 more shielded points, showed also an overestimation of the ambient dose equivalent rate by a factor as high as 20 in comparison with simulated results. Results are not conclusive and a more refined study is necessary. However, neutron emission rate of the source-term of radiation must be investigated and an special caution must be taken in the experimental measurements, by discriminating of the target selected for the irradiations and utilizing a matrix response suitable for the passive detectors (e.g. TLD) utilized in the experiments, instead of a matrix response (e.g. UTA4) developed for scintillation detectors.

Feasibility of EBT Gafchromic films for comparison exercises among standard beta radiation fields.

The feasibility of using radiochromic films to verify the metrological coherence among standard beta radiation fields was evaluated. Exercises were done between two Brazilian metrology laboratories in beta fields from (90)Sr/(90)Y, (85)Kr and (147)Pm radiation sources. Results showed that the radiochromic film was useful for field mapping aiming uniformity and alignment verification and it was not reliable for absorbed dose measurements only for (147)Pm beta field.

Use of a TLD-based multisphere spectrometry system to measure the neutron spectra around a not-self-shielded PET cyclotron: Preliminary results.

In the present work, we utilized the BSS system with TLD-600 and TLD-700 to measure the neutron spectra around the GE-PETtrace 8 cyclotron of the Development Centre of Nuclear Technology (CDTN/CNEN) in Belo Horizonte, Brazil. The cyclotron is capable of accelerating protons up to 16.5 MeV, to production of fluorine-18. Four points inside the bunker of the cyclotron were studied. Two points in front of the primary radiation beam and other two opposed to the primary radiation beam. The measurements were unfolded with the BUMS and the NSDUAZ computer codes. The dosimetric quantities obtained were in agreement with the other published data and were coherent with the expected from theoretical estimates obtained from source term informed by the manufacturer of the cyclotron.

Low dose of propranolol down-modulates bone resorption by inhibiting inflammation and osteoclast differentiation.

BACKGROUND AND PURPOSE: Bones are widely innervated, suggesting an important role for the sympathetic regulation of bone metabolism, although there are controversial studies. We investigated the effects of propranolol in a model of experimental periodontal disease. EXPERIMENTAL APPROACH: Rats were assigned as follows: animals without ligature; ligated animals receiving vehicle and ligated animals receiving 0.1, 5 or 20 mg·kg(-1) propranolol. After 30 days, haemodynamic parameters were measured by cardiac catheterization. Gingival tissues were removed and assessed for IL-1ß, TNF-α and cross-linked carboxyterminal telopeptides of type I collagen (CTX) by elisa, or intercellular adhesion molecule 1 (ICAM-1), receptor activator of NF-κ B ligand (RANKL) and osteoprotegerin (OPG) by Western blot analysis. Sections from the mandibles were evaluated for bone resorption. Also, we analysed the ability of propranolol to inhibit osteoclastogenesis in vitro. RESULTS: Propranolol at 0.1 and 5 mg·kg(-1) reduced the bone resorption as well as ICAM-1 and RANKL expression. However, only 0.1 mg·kg(-1) reduced IL-1ß, TNF-α and CTX levels as well as increased the expression of OPG, but did not alter any of the haemodynamic parameters. Propranolol also suppressed in vitro osteoclast differentiation and resorptive activity by inhibiting the nuclear factor of activated T cells (NFATc)1 pathway and the expression of tartrate-resistant acid phosphatase (TRAP), cathepsin K and MMP-9. CONCLUSIONS AND IMPLICATIONS: Low doses of propranolol suppress bone resorption by inhibiting RANKL-mediated osteoclastogenesis as well as inflammatory markers without affecting haemodynamic parameters.