Cytotoxicity of metals is important because some metals are potential mutagens able to induce tumors in humans and experimental animals. Chromium can damage DNA in several ways, including DNA double strand breaks (DSBs) which generate chromosomal aberrations, micronucleus formation, sister chromatid exchange, formation of DNA adducts and alterations in DNA replication and transcription. In our study, water samples from three sites in the Córrego dos Bagres stream in the Franca municipality of the Brazilian state of São Paulo were subjected to the comet assay and micronucleus test using erythrocytes from the fish Oreochromis niloticus. Nuclear abnormalities of the erythrocytes included blebbed, notched and lobed nuclei, probably due to genotoxic chromium compounds. The greatest comet assay damage occurred with water from a chromium-containing tannery effluent discharge site, supporting the hypothesis that chromium residues can be genotoxic. The mutagenicity of the water samples was assessed using the onion root-tip cell assay, the most frequent chromosomal abnormalities observed being: c-metaphases, stick chromosome, chromosome breaks and losses, bridged anaphases, multipolar anaphases, and micronucleated and binucleated cells. Onion root-tip cell mutagenicity was highest for water samples containing the highest levels of chromium.
The use of medicinal plants by the general population is an old and still widespread practice, which makes studies of their genotoxicity essential. Psidium guajava L. and Achillea millefolium L. are examples of plants commonly used in popular medicine. P. guajava L. is indicated for diarrhea and also as an antiseptic, while A. millefolium L. is indicated as an analgesic, antispasmodic, digestive, diuretic, antiseptic, astringent, emollient, wound healer and hemorrhoid medication. The aim of this study was to determine the effects of the infusions of these two plant species on chromosomes and the cell cycle. Leaves from the plants were used to prepare infusions, in the same manner as teas, but at two different concentrations. Allium cepa L. root-tip cells (P. guajava L. -2.62 and 26.2 mg/mL, and A. millefolium L. -3.5 and 35.0 mg/mL) and Wistar rat bone marrow cells (P. guajava L. -2.62 and 26.2 mg/100g body weight, and A. millefolium L. -3.5 and 35.0 mg/100g body weight) were used as in vivo plant and animal test systems, respectively. Human peripheral blood lymphocytes (P. guajava L. -0.262 and 2.62 µg/mL culture medium, and A. millefolium L. -0.35 and 3.5 µg/mL culture medium) were used as in vitro test system. The P. guajava L. infusion at the higher concentration caused a statistically significant inhibition of cellular division in the onion root-tip cells, not observed in onion root-tip cells treated with A. millefolium L. No statistically significant alterations were found, as compared to untreated controls, in either the cell cycle or the number of chromosome alterations, after treatments with either plant, in rat cells or in cultured human lymphocytes. These results regarding the cytotoxicity and mutagenicity of these plants provide valuable information about the safety of using them as therapeutic agents.
A new palatal procedure for snoring/obstructive sleep apnea (OSA) is described. The procedure was named as barbed reposition pharyngoplasty (BRP). The technique is described step by step. The new surgical technique was carried out in ten adult OSA patients with mean age of 53.4 ± 12.4 years (average 30-70) with confirmed retropalatal obstruction. In this pilot study; we assessed the feasibility by calculating the number of cases that failed to be operated and converted to other palatal technique during the same surgical setting, safety was assessed by evaluating both intra-operative and post-operative complications, teachability measured by the learning curve of our team members (the time of surgical procedure). In this study, the technique is proved to be feasible in all cases. There were no significant intra-operative or post-operative complications. Objective clinical improvement was confirmed by polysomnography 6 months post-operative with significant decrease in mean AHI from 43.65 ± 26.83 to 13.57 ± 15.41 (P = 0.007), daytime sleepiness assessed by Epworth Sleepiness Scale from 11.6 ± 4.86 to 4.3 ± 2 (P < 0.01), ODI from 44.7 ± 27.3 to 12.9 ± 16.3 (P = 0.004). Operative time decreased over the course of the study with an initial steep ascent in technical skill acquisition followed by more gradual improvement, and a steady decrease in operative time to as short as 20 min. Our preliminary results suggest that BRP technique is feasible, safe and effective in management of OSA patients. Moreover, it is easy to learn even for not experienced surgeons, less time consuming and with no significant complications.
Genotoxicity studies on toxic metals and their organic compounds are very important, especially so in the investigation of the effects of these compounds on the aquatic environments where they tend to accumulate. The use of endemic aquatic organisms as biological sentinels has proved useful to environmental monitoring. We assessed the mutagenic potential of tributyltin (TBT) and inorganic lead (PbII) using samples of the fish Hoplias malabaricus (commonly called traíra) using the comet assay and the piscine micronucleus and chromosome aberration tests. Eighteen H. malabaricus were acclimatized in three individual aquariums, each containing six fish, six fish being exposed to 0.3 µg/g of body weight (bw) of TBT, six to 21 µg/g bw of PbII and six being used as controls. Exposure to TBT and PbII was achieved by feeding the fish every five days with Astyanax (a small fish that is part of the normal diet of H. malabaricus) which had been injected with solutions of TBT, PbII or with water (the control group). After two months the H. malabaricus were sacrificed and their peripheral blood collected and subjected to the comet and micronucleus assays, the chromosome aberration assay being conducted using kidney-tissue. Although the comet assay showed now mutagenic effects at the lead concentrations used but encountered results with TBT, the micronucleus and chromosome aberrations assays both indicated that TBT and PbII are potentially mutagenic (p < 0.01), the micronucleus assay showing morphological alterations of the nucleus.
Introduction. Maxillary sinus surgery is a reliable and predictable treatment option for the prosthetic rehabilitation of the atrophic maxilla. Nevertheless, these interventions are not riskless of postoperative complications with respect to implant positioning in pristine bone.
Aim. The aim of this paper is to report the results of a clinical consensus of experts (periodontists, implantologists, maxillofacial surgeons, ENT, and microbiology specialists) on several clinical questions and to give clinical recommendations on how to prevent, diagnose, and treat postoperative infections.
Materials and Methods. A panel of experts in different fields of dentistry and medicine, after having reviewed the available literature on the topic and taking into account their long-standing clinical experience, gave their response to a series of clinical questions and reached a consensus.
Results and Conclusion. The incidence of postop infections is relatively low (2%–5.6%). A multidisciplinary approach is advisable. A list of clinical recommendation are given.
The results of the study suggest that a careful multi-tasking preoperative management, including an ENT assessment with fiberoptic endoscopy and a radiological evaluation extended to the ostio-meatal complex, is very useful in candidates for SFE.
Patients undergoing BRP standing alone or as part of a multilevel approach for the treatment of OSAHS have a reasonable expectation for success with minimal morbidity.
The comet assay was used to study the sensitivity of the widely distributed freshwater bivalve mollusk Corbicula fluminea to the DNA-damaging alkylating-agent methylmethane sulfonate (MMS). This study was undertaken to ascertain if C. fluminea is a good bioindicator of pollutants in aquatic environments and identify which C. fluminea tissue is most effective and practical for genotoxicity studies. The mollusks were exposed to 0.6, 1.2 or 2.4 X 10 -4 M MMS for 40 min and their hemolymph, gill tissue and digestive gland tissue assessed for the level of DNA damage and the time needed for the tissues to recovery. Regression analysis showed a direct linear dose-response relationship between MMS concentration and the number of damaged cells for hemolymph and digestive gland tissue but a quadratic relationship for gill tissue, which made the interpretation the gill tissue results difficult. The basal level of DNA damage to gill tissue was very high, possibly because gill is the organs most directly exposed to environmental toxins and mutagenic agents. Although all three types of tissue produced useful results, hemolymph and digestive gland tissue produced more reproducible and reliable results. Hemolymph was the best sample type in that it was easy to obtain and handle, while gill tissue required more manipulation to obtain cell suspensions. Our results indicate that C. fluminea is an optimal bioindicator for the determination genotoxic contaminants in aquatic environments.
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