Medication-related osteonecrosis of the jaws after tooth extraction in senescent female mice treated with zoledronic acid: Microtomographic, histological and immunohistochemical characterization.

Treatment with cumulative dosages of zoledronic acid (ZA) in elderly patients is a risk factor for the development of medication-related osteonecrosis of the jaws (MRONJ), mainly related to surgical triggers such as tooth extraction. However, animal models for the investigation and understanding of MRONJ pathophysiology in senescent and postmenopausal stages remains to be developed and characterized. The aim of this study was to analyze MRONJ development in senescent female mice treated with cumulative dosages of ZA. For this purpose, twenty 129/Sv female mice, 64 weeks old, were treated with 0.9% saline solution as control group (n = 10), and with ZA at 250µg/Kg (n = 10), once a week, starting 4 weeks before the upper right incisor extraction and until the end of the experimental time points (7 days and 21 days). At 7 and 21 days post-surgery, specimens were harvested for microCT, histological, birefringence and immunohistochemical analysis. Clinically, an incomplete epithelialization was observed in ZA group at 7 days and a delayed bone matrix mineralization and collagen maturation at 7 and 21 days compared to the controls. Controls revealed sockets filled with mature bone at 21 days as observed by microCT and birefringence, while ZA group presented delayed bone deposition at 7 and 21 days, as well increased leukocyte infiltration and blood clot at 7 days, and increased bone sequestrum and empty osteocyte lacunae at 21 days (p<0.05). Also, ZA group presented decreased quantity of TGFb+ and Runx-2+ cells at 7 days, and decreased quantity of TRAP+ osteoclasts compared to the control at 21 days (p<0.05). Altogether, these data demonstrate the usefulness of this model to understanding the pathophysiology of MRONJ.

Could male reproductive system be the main target of subchronic exposure to manganese in adult animals?

Manganese (Mn) is one of the most common chemical elements on Earth and an essential micronutrient in animal organism. However, in supraphysiological levels and long-term exposures, it is a potential toxicant. Although nervous system is the most studied in relation to Mn toxicity, other tissues can have their function impaired by Mn in high doses. The present study investigated the possible adverse effects of subchronic exposure to supraphysiologic level of Mn (5 mg/kg or 15 mg/kg, intraperitoneally) on reproductive, neurobehavioral, renal and hepatic parameters of male rats. For the first time, the vulnerability of these parameters to Mn was concomitantly investigated. While our results demonstrate that Mn treatments were not sufficient to produce a marked effect of neurotoxic, hepatotoxic or renal toxicity in adult rats, we found typical indicators of reproductive toxicity such as histopathological changes (major in testes and epididymis) and impaired sperm concentration and quality. Mn, under these experimental conditions, seems to exert reproductive toxicity by different testicular mechanisms, i.e. direct and indirect action on germ cells. On the other hand, exposure to Mn did not change the pattern of cognitive and emotional behaviors and the histological organization of kidneys of experimental rats. The liver showed a weight increasement and hidropic degeneration, probable due to the detoxification overload. In summary, for the first time it was demonstrated that adult male reproductive system was more sensitive to Mn toxicity than nervous, hepatic and renal systems, although nervous system is known as the main target tissue of this metal.

Expression of miRNA-146a, miRNA-155, IL-2, and TNF-α in inflammatory response to Helicobacter pylori infection associated with cancer progression.

miRNAs appear to play an important role in controlling the expression of several genes, and they are a potential biomarker and prognostic tool in gastric diseases. We analyzed 53 controls, 86 patients with gastritis, and 19 patients with gastric cancer. Real-time-PCR was used to determine the expression levels of miRNA-146a, miRNA-155, IL-2, and TNF-α. The subsequent analysis of the target genes was performed using the bioinformatics approach. There was no difference in IL-2 expression between the groups. However, there was a significant increase in TNF-α expression in the gastritis group relative to the control and a significant decrease in the gastric cancer group relative to the control. There was also a statistically significant increase in miRNA-146a and miRNA-155 expression in the gastritis group relative to the control, but not in the gastric cancer group. Similar results were found when the presence of H. pylori was considered. The data revealed an increase in miRNA-146a and miRNA-155 expression but not enough to control the expression of TNF-α. The presence of H. pylori was found to affect increases in TNF-α and microRNA expression, and miRNA-146a and miRNA-155 alone were not able to eliminate bacteria or restore tissue homeostasis.

Fish pollutants MeHg and Aroclor cause permanent structural damage in male gonads and kidneys after prepubertal exposure.

This study investigated whether or not prepubertal exposure to the fish contaminants methylmercury (MeHg) and the polychlorinated bisphenol Aroclor in low doses interferes with the histomorphometry of the testes, epididymis, liver and kidneys in rats. Wistar male rats, 21 days old, were allocated into the following: control (n = 17, received corn oil), MeHg (n = 17, received MeHg at 0.5 mg/kg/day), Aroclor (n = 17, received Aroclor at 1.0 mg/kg/day), low mix (n = 18, received MeHg at 0.05 mg/kg/day and Aroclor at 0.1 mg/kg/day), high mix (n = 18, received MeHg at 0.5 mg/kg/day and Aroclor at 1.0 mg/kg/day). Dosing continued from post natal day (PND) 23 to 53, by gavage. Euthanasia was performed on PND 53; or, after an interval of 62 days without exposure to chemicals, on PND 115. The degree of maturation of the seminiferous epithelium was delayed in chemical-exposed groups and testicular interstitial oedema was observed at adulthood. The pattern of male gonad organization was changed in the Aroclor group on PND 53 and in all treated groups at adulthood. The animals from Aroclor, low mix and high mix groups showed a reduction in the number of Sertoli cells. Histological evidence of renal injury was observed in all chemical-exposed groups in both ages. A probable target for MeHg and Aroclor in the reproductive system was Sertoli cells, in which possible dysfunctions could be linked to the other testicular alterations. Curiously, the main deleterious effects were late outcomes, along with the absence of synergistic interaction of MeHg and Aroclor in the parameters investigated. In conclusion, fish pollutants MeHg and Aroclor caused permanent structural damage in male gonads and kidneys after prepubertal exposure, without showing clear chemical interactions.

Efeito do tratamento com melatonina sobre a produção de metástases neoplasias / Result of the treatment with melatonin inthe production of neoplasic metastasis

Introdução: Neoplasias são células com proliferação e diferenciação anormais. Quando essas células tornam-se capazes de originar outras células em tecidos e vasos diferentes do inicial são denominadas metástases. A melatonina (N-acetil-5-metoxitripamina) é um hormônio secretado pela glândula pineal e que tem associação com o controle celular tumoral. Objetivo: pretendeu-se avaliar o efeito do tratamento com melatonina sobre a produção e crescimento de metástase linfática do tumor sólido de Ehrlich (TE) em camundongos. Método: foram empregados 14 camundongos distribuídos em 2 grupos: controle (GC, N = 07 / 0,1ml de solução fisiológica, via oral, 1x/dia) e teste (GT, N = 07 / 10mg/kg de melatonina, via oral, 1x/ dia). Todos os animais foram inoculados com 10 6 células tumorais no coxim plantar da pata traseira direita. Resultados e Discussão: D=decorridos 17 dias de tratamento os animais foram eutanasiados, removemos as 02 patas traseiras para avaliar o peso da massa tumoral sendo que o grupo controle apresentou peso maior (GC = 0,62 ± 0,14). Também foi removido o linfonodo poplíteo para mensuração da área, constatando redução significativa no grupo teste (GT = 4,37 ± 1,58). A redução da área do linfonodo pode ser associada a uma redução no número de células tumorais presentes nos linfonodos (GT = 62,8 ± 13,07). Conclusão: Concluímos que o tratamento com melatonina reduziu significativamente o crescimento tumoral e metastático do TE.

Introduction: Neoplasms are cells with unusual proliferation and differentiation. When these cells become able to generate other cells in material and veins different from the beginning one arenamed metastasis. The melatonin (N-acetil-5-methoxytryptamine) is a hormone secreted by the pineal gland and it has association with the tumor cell control. Objective: the general aim was to evaluate the treatment result with melatonin on the metastasis lymphatic production and growth of the Ehrlich Tumor in mice. For this experience, 14 mice were used and shared in 2 groups: control (GC, N = 07 / 0,1ml of sterilizing solution, oral, once a day) and test (GT, N = 07 / 10mg/kg of melatonin, oral, once a day). All the animals were inoculated with 106 tumor cells in the footpad of the right back paw. Results and discussion: after 17 days of treatment the animals were euthanized and 2 back paws were removed to evaluate the tumor bulk weight considering that the control group was heavier (GC = 0,62 ± 0,14). The popliteallymph node was also removed for the area measurement where asmaller area for the test group was observed (GT = 62,8 ± 13,07). Conclusion: we concluded that the treatment with melatonin meaningfully reduced the metastatic growth.

Atividade antitumoral do Ageratum conyzoides L. (Asteraceae) / Antitumoral activity of the Ageratum conyzoides L. (Asteraceae)

O Ageratum conyzoides, vegetal conhecido popularmente no Brasil é constituído por várias substâncias químicas, dentre elas os flavonóides, aos quais já foi atribuída a atividade antitumoral. Neste estudo foi avaliado o efeito das frações clorofórmica e metanólica do extrato AcOEt das folhas sobre o crescimento do tumor de Ehrlich. Foi constatado que o tratamento com as frações metanólicas, nas doses de 50 mg/kg de peso foi eficaz, inibindo o crescimento tumoral. A porcentagem de inibição para a fração metanólica estabilizada foi de 69,84 por cento e de 68,25 por cento para a fração metanólica não estabilizada. Estudos posteriores se fazem necessários para esclarecer quais os mecanismos envolvidos nesta inibição do crescimento tumoral.

Ageratum conyzoides, a popular vegetal in Brazil, is composed by many chemical compounds, including flavonoids, and antitumoral activity has been attributed to it. In this assay the effect of chloroform and methanol fractions from EtOAc extract of the leaves on the growth of the Ehrlich tumor was evaluated. Under our experimental conditions we have observed that the treatment with methanol fractions, under the dosage of 50 mg/kg was efficient on inhibiting the tumoral growth. There was an inhibition percentage of 69.84 percent to the stabilized methanol fraction and 68.25 percent to the non-stabilized fraction. Further studies are necessary to clarify which mechanisms are involved in the inhibition of the tumoral growth.

Effect of L-Arginine and L-NAME treatments on polymorphonuclear leukocytes and mononuclear cells influx during tumor growth.

PURPOSE: Evaluate polymorphonuclear leukocytes (PMN's) and mononuclear cells (MN's) involvement in the Ehrlich s solid tumor (ET) growth. METHODS: 90 Swiss mice were inoculated with 10(7) tumor cells (sc), distributed in three groups and treated once a day, via intraperitoneal (ip), with 0.1ml of diluent, L-Arginine (20mg/Kg) or L-NAME (20mg/Kg). After 7, 15 and 30 days of treatment, ten animals of each group were euthanized, the tumor mass was removed, processed and fixed for HE. Later, a morphometric analysis of the total area, parenchyma, necrosis, tumor stroma and PMN's leukocytes and MN's cells influx was performed. RESULTS: The L-Arginine treatment increased PMN's influx in the initial stage, whereas L-NAME reduced it. Our data suggests that NO effect on PMN's migration is dose-dependent. On the other hand, the MN s cells influx was reduced by L-NAME treatment at all evaluated periods and at the same periods an increase in tumor growth was observed. CONCLUSION: At initial stages of tumor implantation, both PMN's leukocytes and MN's cells act together to control ET development.

Effect of L-Arginine and L-NAME treatments on polymorphonuclear leukocytes and mononuclear cells influx during tumor growth / Efeito dos tratamentos com L-Arginina e L-NAME sobre o influxo de leucócitos polimorfonucleares e células mononucleares durante o desenvolvimento tumoral

PURPOSE: Evaluate polymorphonuclear leukocytes (PMN's) and mononuclear cells (MN's) involvement in the Ehrlich´s solid tumor (ET) growth. METHODS: 90 Swiss mice were inoculated with 10(7) tumor cells (sc), distributed in three groups and treated once a day, via intraperitoneal (ip), with 0.1ml of diluent, L-Arginine (20mg/Kg) or L-NAME (20mg/Kg). After 7, 15 and 30 days of treatment, ten animals of each group were euthanized, the tumor mass was removed, processed and fixed for HE. Later, a morphometric analysis of the total area, parenchyma, necrosis, tumor stroma and PMN's leukocytes and MN's cells influx was performed. RESULTS: The L-Arginine treatment increased PMN's influx in the initial stage, whereas L-NAME reduced it. Our data suggests that NO effect on PMN's migration is dose-dependent. On the other hand, the MN´s cells influx was reduced by L-NAME treatment at all evaluated periods and at the same periods an increase in tumor growth was observed. CONCLUSION: At initial stages of tumor implantation, both PMN's leukocytes and MN's cells act together to control ET development.

OBJETIVO: Avaliar o envolvimento de leucócitos polimorfonucleares (PMN's) e células mononucleares (MN's) no crescimento do Tumor Sólido de Ehrlich (TE). MÉTODOS: 90 camundongos Suíços foram inoculados com 10(7) células tumorais (sc), distribuídos em três grupos e tratados uma vez ao dia, via intraperitoneal (ip), com 0.1ml de diluente, L-Arginina (20mg/Kg) ou L-NAME (20mg/Kg). Após 7, 15 e 30 dias, dez animais de cada grupo foram eutanasiados, a massa tumoral foi removida, processada e corada pela HE. Posteriormente, foi realizada análise morfométrica das áreas total, parênquima, necrose, estroma e influxo de leucócitos PMN's e células MN's. RESULTADOS: O tratamento com L-Arginina favoreceu o influxo de PMN's em períodos iniciais, enquanto o tratamento com L-NAME o reduziu. Nosso estudo sugere que o efeito do ON sobre a migração de PMN's é dose-dependente. Por outro lado, o influxo de células MN´s foi contido pelo tratamento com L-NAME em todos os períodos avaliados, mesmos períodos em que se observou um aumento no crescimento tumoral. CONCLUSÃO: Em fases iniciais do implante tumoral, ambos, leucócitos PMN's e células MN's, atuam juntos no controle do desenvolvimento do TE.

Efeito do tratamento com indometacina e parecoxibe na evolução do tumor sólido de Ehrlich / Effect of treatment with indomethacin and parecoxib in the development of solid tumor of Ehrlich

Ampla literatura demonstra a participação de cicloxigenases (COXs: COX-1 e/ou COX-2) na evolução de várias neoplasias humanas e experimentais. Este estudo teve por objetivo comparar o efeito de um inibidor não seletivo de COX e um específico de COX-2 na evolução do tumor sólido de Ehrlich (TE). Para tanto, camundongos foram inoculados subcutâneamente com 1 x10 7 células de TE e tratados com indometacina (inibidor de COX-1 e COX-2) ou parecoxibe (inibidor de COX-2), ambos na concentração de 1 mg/kg de peso, 1x/dia, ip, ou com diluente (0,1 ml, 1x/dia, ip). Decorridos sete e quinze dias, os animais foram sacrificados e a massa tumoral avaliada quanto: peso; dimensões da área total, de necrose, de parênquima e estroma tumorais; quantificação de células mononucleares, polimorfonucleares, linfócitos CD3mais, linfócitos CD4mais e linfócitos CD8 mais. O tratamento com indometacina reduziu o peso do TE, a área total e a área do parênquima tumoral, apenas após quinze dias de tratamento e promoveu aumento no influxo de linfócitos CD3mais e CD8mais em todos os períodos avaliados. O tratamento com parecoxibe também reduziu o peso tumoral, porém promoveu um acréscimo na área total do TE, no parênquima e no influxo de linfócitos CD3mais e CD8mais, aos quinze dias de tratamento. Esses resultados sugerem que a COX-1 está mais envolvida no escape do crescimento do TE, ou que COX-1 e COX-2 atuam em fases distintas da evolução do TE.

Efeito do tratamento com isoflavona no crescimento do tumor sólido de Ehrlich / Effect of Isoflavone treatment on Solid Ehrlich Tumor growth

Estudos epidemiológicos revelam que o consumo regular de soja reduz ou suprime o câncer de mama, sendo esse fato associado à presença de isoflavonas, fitoestrógenos contidos nesses grãos. Atribui-se ao estrogênio a facilitação do crescimento de neoplasias mamárias humanas e, por conseqüência, o uso do fitoestrogênio vem se mostrando uma terapia alternativa ao uso de estrogênio. Neste estudo, avaliou-se a ação das isoflavonas sobre o crescimento do tumor de Ehrlich, baseando-se nas determinações de peso, área e proliferação celular. Para tanto, administrou-se uma suspensão de isoflavona, via intraperitoneal, na dose de 20 mg/kg de peso, por 20 dias. Constatou-se que o tratamento com isoflavona é capaz de interferir no ciclo de divisão celular, pois o número de figuras de mitose foi significativamente reduzido no grupo tratado. O peso e as dimensões da massa tumoral não apresentaram dife renças significativas entre os grupos, fato que merece investigação futura...