Periodontal therapy for patients before and after radiotherapy: A review of the literature and topics of interest for clinicians.

BACKGROUND: To review and discuss important topics regarding periodontal treatment pre- and post-radiotherapy for head and neck cancer in human patients; to discuss the references for adequate techniques, the appropriate moment for tooth extractions and periodontal management; and to discuss the prevention of osteoradionecrosis. MATERIAL AND METHODS: Thirty-nine studies including original studies, randomized clinical trials (RCTs) and reviews were searched in online databases MEDLINE (PubMed) and the Cochrane library. No year of publication restriction was applied. RESULTS: Language was restricted to English, and the following Medical Subject Heading terms were used: radiotherapy, radiation therapy and periodontal treatment. Studies regarding periodontal treatment and tooth extraction that involved clinical management of irradiated patients were selected. CONCLUSIONS: The treatment of periodontal diseases before radiotherapy is mainly required to avoid future dental extraction and to reduce the development of osteoradionecrosis. Periodontal treatment in irradiated patients mostly includes scaling and root planing, extraction of condemned teeth and topical and systemic antimicrobial therapy. Tooth removal should be planned at least 14 days before the first day of radiation treatment. Particular care and mouthwashes should be taken during and after radiation. CLINICAL SIGNIFICANCE: The management of irradiated patients represents a challenge for health professionals, including dentists. It is important to establish recommendations for clinicians concerning dental and periodontal management in irradiated patients before, during and after treatment.

Implant osseointegration in irradiated bone: an experimental study.

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the effect of radiotherapy on the osseointegration of dental implants in the tibia and the action of platelet-rich plasma (PRP) as an adjuvant therapy. MATERIAL AND METHODS: A total of 18 rabbits received two implants in each tibial epiphysis, totalizing 72 implants. The control group (group I) was composed by six rabbits and did not receive radiotherapy. The test groups (II and III) received a single dose of 1727 cGy. Group II was composed by six irradiated animals and group III by six animals that received irradiation and PRP during implant placement. The implant success rate, the bone-implant contact (BIC), and the bone volume were analyzed. RESULTS: There was no osseointegration in four of the implants, three in group II and one in group III. Total BIC was significantly higher in group I, when compared to the other groups. There was a significant difference of osteoid BIC only between irradiated animals (group II, 8.5%; group III, 4.7%; p = 0.001). On the other hand, the mineralized BIC was significantly higher in group I. Furthermore, group II had a lower mineralized BIC than group III (p = 0.002). Bone volume was higher in the control group (41.3%), followed by group III (33.4%) and II (25.1%), with differences between groups I and II (p = 0.001) and groups II and III (p = 0.022). CONCLUSIONS: The present study showed that both the bone volume and BIC were higher in the control group. However, the failure rates of the implants were low in both irradiated groups. The PRP was a positive adjuvant in the osseointegration process.

Characterization of Capsicum species using anatomical and molecular data.

Capsicum species are frequently described in terms of genetic divergence, considering morphological, agronomic, and molecular databases. However, descriptions of genetic differences based on anatomical characters are rare. We examined the anatomy and the micromorphology of vegetative and reproductive organs of several Capsicum species. Four Capsicum accessions representing the species C. annuum var. annuum, C. baccatum var. pendulum, C. chinense, and C. frutescens were cultivated in a greenhouse; leaves, fruits and seeds were sampled and their organ structure analyzed by light and scanning electronic microscopy. Molecular accession characterization was made using ISSR markers. Polymorphism was observed among tector trichomes and also in fruit color and shape. High variability among accessions was detected by ISSR markers. Despite the species studied present a wide morphological and molecular variability that was not reflected by anatomical features.

ESTRÉS OXIDATIVO ASOCIADO A LA EXPOSICIÓN OCUPACIONAL A SUSTANCIAS QUÍMICAS

El estrés oxidativo en la actualidad es una problemática que se ha asociado a diferentes estados patológicos. En este trabajo nos propusimos compilar información, a partir de la bibliografía existente en la última década, que versara sobre el estrés oxidativo y su posible relación con la exposición ocupacional a diferentes sustancias tóxicas, específicamente lo relacionado con la actividad enzimática, entre ellas, de la superóxido-dismutasa, la glutatión-peroxidasa y la catalasa, y con productos de lipoperoxidación como el malonildialdehído, donde se reportan alteraciones en el balance antioxidante del organismo a la exposición ocupacional a diferentes sustancias quimiotóxicas. Esto pudiera revelar que ocurran alteraciones fisiológicas en momentos tempranos de la exposición; por lo tanto, se requiere de estudios que continúen evaluando el estrés oxidativo y su posible asociación a los factores de riesgo existentes en el ambiente laboral.

Leukocyte ultrastructure, hematological and serum biochemical profiles of ostriches (Struthio camelus).

In the last decade ostrich farms spread throughout the world as an alternative source of investment. Although previous studies have reported hematology and biochemical values for ostriches from several regions of the world, little information is available regarding leukocyte morphology. This study reports the morphology and ultrastructure of ostrich leukocytes and hematology and biochemical values from birds raised in Brazil. Heterophils presented a lobulated nucleus, and fusiform, and acidophilic and peroxidase-negative granules. Ultrastructurally, 2 kinds of cytoplasmic granules were observed: one was large and fusiform and the other smaller with heterogeneous morphology and electrondensity; granules were peroxidase-negative. Eosinophils had a kidney-shaped eccentrically placed nucleus that was rarely lobulated and eosinophilic, round, and peroxidase-positive granules. At the ultrastructure level, 2 main kinds of granules with the same size and form but different electron density were seen; granules were peroxidase-positive. Lymphocytes and thrombocytes had the same characteristics of other avian species; monocytes presented morphological heterogeneity. Hematological and serum biochemical profiles had no sex influence and were established for ostriches raised in southeastern Brazil. These parameters will help the diagnosis of specific ostrich pathologies and serve as basic knowledge for studies in immunology and comparative avian pathology.

EVALUACIÓN EPIDEMIOLÓGICA DE LA INVALIDEZ TOTAL. CUBA 2005

Se realizó un estudio epidemiológico de tipo descriptivo de la invalidez total permanente (ITP) en los trabajadores cubanos en el año 2005, siendo la fuente de los datos el Sistema Automatizado de Peritaje Médico Laboral (SAPERMEL), a partir de la información suministrada por todas las Comisiones de Peritaje Médico Laboral del país, con el objetivo de detectar los principales factores que condicionan el comportamiento a nivel de los territorios y tomar medidas para su corrección. Del total de los casos peritados, se le otorgó la ITP a 6 786 trabajadores, que representan el 13,9% de la población atendida, con una tasa de 234,8 por 10 000 trabajadores, siendo superior a ésta las presentadas por las provincias de Santiago de Cuba, Holguín, Guantánamo, Camagüey, Ciego de Ávila y Sancti Spíritus. Se observó un predominio de la invalidez total por enfermedades del sistema nervioso, del aparato circulatorio y por cáncer, estas últimas son coincidentes con las primeras causas de muerte, donde el cáncer ocupa el primer lugar en los grupos de edades de 15 a 49 y de 50 a 64 años, siendo, en nuestro caso, a partir de la cuarta década de vida, superior el dictamen de ITP por enfermedad del sistema nervioso en las provincias de Camagüey, Granma y La Habana, y por cáncer en las de Guantánamo, Ciego de Ávila y Granma. De forma general, la tasa más elevada (189,9) la presentan las enfermedades cerebro vasculares.

Canine external carotid vasoconstriction to methysergide, ergotamine and dihydroergotamine: role of 5-HT1B/1D receptors and alpha2-adrenoceptors.

The antimigraine drugs methysergide, ergotamine and dihydroergotamine (DHE) produce selective vasoconstriction in the external carotid bed of vagosympathectomized dogs anaesthetized with pentobarbital and artificially respired, but the receptors involved have not yet been completely characterized. Since the above drugs display affinity for several binding sites, including alpha-adrenoceptors and several 5-HT1 and 5-HT2 receptor subtypes, this study has analysed the mechanisms involved in the above responses. Intracarotid (i.c.) infusions during 1 min of methysergide (31-310 microg min(-1)), ergotamine (0.56-5.6 microg min(-1)) or DHE (5.6-31 microg min(-1)) dose-dependently reduced external carotid blood flow (ECBF) by up to 46+/-4, 37+/-4 and 49+/-5%, respectively. Blood pressure and heart rate remained unchanged. The reductions in ECBF by methysergide were abolished and even reversed to increases in animals pre-treated with GR127935 (10 microg kg(-1), i.v.). The reductions in ECBF by ergotamine and DHE remained unchanged in animals pre-treated (i.v.) with prazosin (300 microg kg(-1)), but were partly antagonized in animals pre-treated with either GR127935 (10 or 30 microg kg(-1)) or yohimbine (1000 microg kg(-1)). Pre-treatment with a combination of GR127935 (30 microg kg(-1)) and yohimbine (1000 microg kg(-1)) abolished the responses to both ergotamine and DHE. The above doses of antagonists were shown to produce selective antagonism at their respective receptors. These results suggest that the external carotid vasoconstrictor responses to methysergide primarily involve 5-HT1B/1D receptors, whereas those to ergotamine and DHE are mediated by 5-HT1B/1D receptors as well as alpha2-adrenoceptors.

The 5-HT1-like receptors mediating inhibition of sympathetic vasopressor outflow in the pithed rat: operational correlation with the 5-HT1A, 5-HT1B and 5-HT1D subtypes.

1. It has been suggested that the inhibition of sympathetically-induced vasopressor responses produced by 5-hydroxytryptamine (5-HT) in pithed rats is mediated by 5-HT1-like receptors. The present study has re-analysed this suggestion with regard to the classification schemes recently proposed by the NC-IUPHAR subcommittee on 5-HT receptors. 2. Intravenous (i.v.) continuous infusions of 5-HT and the 5-HT1 receptor agonists, 8-OH-DPAT (5-HT1A), indorenate (5-HT1A), CP 93,129 (5-HT1B) and sumatriptan (5-HT(1B/1D)), resulted in a dose-dependent inhibition of sympathetically-induced vasopressor responses. 3. The sympatho-inhibitory responses induced by 5-HT, 8-OH-DPAT, indorenate, CP 93,129 or sumatriptan were analysed before and after i.v. treatment with blocking doses of the putative 5-HT receptor antagonists, WAY 100635 (5-HT1A), cyanopindolol (5-HT(1A/1B)) or GR 127935 (5-HT(1B/1D)). Thus, after WAY 100635, the responses to 5-HT and indorenate, but not to 8-OH-DPAT, CP 93,129 and sumatriptan, were blocked. After cyanopindolol, the responses to 5-HT, indorenate and CP 93,129 were abolished, whilst those to 8-OH-DPAT and sumatriptan (except at the lowest frequency of stimulation) remained unaltered. In contrast, after GR 127935, the responses to 5-HT, CP 93,129 and sumatriptan, but not to 8-OH-DPAT and indorenate, were abolished. 4. In additional experiments, the inhibition induced by 5-HT was not modified after 5-HT7 receptor blocking doses of mesulergine. 5. The above results suggest that the 5-HT1-like receptors, which inhibit the sympathetic vasopressor outflow in pithed rats, display the pharmacological profile of the 5-HT1A, 5-HT1B and 5-HT1D, but not that of 5-HT7, receptors.

Anastomose esplenorrenal seletiva profilatica na forma hepatosplenica da esquistossomose. Experiencia de 74 casos. / Prophylactic selective splenorenal anastomosis in the hepatosplenic form of schistosomiasis. Experience of 74 cases

Os autores apresentam os resultados de 74 pacientes portadores de hipertensao porta esquistossomotica sobmetidos a anastomose esplenorrenal seletiva com indicacao profilatica. Houve 2 0bitos (2,7%) e 3 casos de trombose da anastomose (4,05%). O controle endoscopico pos-operatorio das varizes em 40 casos mostrou ausencia em 14 (35%) e reducao em 23, ou seja 57,5%. Em face dos resultados, consideram valida a cirurgia profilatica na forma hepatosplenica da esquistossomose mansonica