Genetic diversity, population structure and ecological niche modeling of Thyrinteina arnobia (Lepidoptera: Geometridae), a native Eucalyptus pest in Brazil.

Thyrinteina arnobia (Lepidoptera: Geometridae) is a native American species. Despite its historical importance as an insect pest in Eucalyptus plantations, more information is needed regarding the population diversity, demography, and climatic variables associated with its distribution in different regions of Brazil. We used a phylogeographic approach to infer the genetic diversity, genetic structure, and demographic parameters of T. arnobia. We also conducted an ecological niche modeling (ENM) to predict suitable areas for T. arnobia occurrence in Brazil and other countries worldwide. Although T. arnobia populations have low genetic diversity in Brazil, we identified mitochondrial haplogroups predominating in different Brazilian regions and high ФST and ФCT values in AMOVA, suggesting a low frequency of insect movement among these regions. These results indicate that outbreaks of T. arnobia in Eucalyptus areas in different regions of Brazil are associated with local or regional populations, with no significant contribution from long-distance dispersal from different regions or biomes, suggesting that pest management strategies would be implemented on a regional scale. In Brazil, the demographic and spatial expansion signals of T. arnobia seem to be associated with the history of geographical expansion of Eucalyptus plantations, a new sustainable host for this species. ENM indicated that isothermality and annual rainfall are critical climatic factors for the occurrence of T. arnobia in tropical and subtropical areas in the Americas. ENM also suggested that T. arnobia is a potential pest in Eucalyptus areas in all Brazilian territory and in regions from Africa, Asia, and Oceania.

Epithelial cyst following subepithelial connective tissue graft: A case report.

BACKGROUND: Various surgical approaches have been employed to manage gingival recession, including subepithelial connective tissue grafting, which has yielded favorable outcomes. METHODS AND RESULTS: We present the case of a 17-year-old patient who developed gingival recession on tooth #6 following an esthetic crown lengthening procedure. The recession was treated with a subepithelial connective tissue graft; however, this case details the occurrence of two epithelial cysts adjacent to the region subjected to the surgical procedure, 6 months after surgery. The treatment involved periodontal surgical intervention, during which the lesions were completely excised and the associated osseous defect was filled using an inorganic bovine bone matrix along with a collagen membrane. The healing progressed without any complications. Histopathological analysis revealed the presence of cystic lesions, which were characterized by a cystic cavity lined with stratified orthokeratinized epithelium with cuboidal cells in some areas surrounded by fibrous connective tissue. The patient's progress was monitored through tomography performed 6 months, 1 year, and 5 years post-procedure, all of which demonstrated the absence of any signs of lesion recurrence. CONCLUSION: This case study emphasizes the effectiveness and predictability of subepithelial connective tissue grafting in the treatment of gingival recession. However, dental professionals should be cautious about the potential risk of gingival recession following esthetic crown lengthening procedures and recognize the potential complications associated with subepithelial connective tissue grafting, such as the observed development of epithelial cysts in this specific case. KEY POINTS: Why is this case new information? We present a case of an epithelial cyst following a subepithelial connective tissue graft, which resulted in buccal cortical bone resorption. The treatment involved excisional biopsy and the use of an inorganic bovine bone matrix with a collagen membrane. What are the keys to the successful management of this case? Successful treatment included periodontal surgery, bone defect filling using an inorganic bovine bone matrix and a collagen membrane, and regular monitoring with CT scans at 6 months, 1 year, and 5 years post-surgery; all showed no recurrence. Success factors included careful surgery, appropriate biomaterial usage, and ongoing follow-up. What are the primary limitations to success in this case? The limitations involve potential complications from subepithelial connective tissue grafting such as cyst development. This report stresses the importance of meticulous patient selection and periodontal phenotype evaluation to minimize risks. Continuous follow-up is critical to detect recurrence and other issues.

Behaviour of personality-screened juvenile Oreochromis niloticus in different challenges: Bold fish present more exploratory capacity and learning to face imposed challenges.

The investigation of cultivation and management techniques that take into account behaviour and animal welfare becomes important due to their direct relationship with animal performance. This study aimed to classify juvenile Oreochromis niloticus by personality and compare their performance at exploration and competition tasks. The new object test was used to select bold and shy animals, which were then tested to see which first approached an object. The food competition test involved placing three feed pellets inside a cylinder and measuring the time taken until the pellet was eaten. The new object test found bold animals with a shorter mean time to approach the object than shy animals approaching 65% of the first object when compared to shy. The food competition test found that the bold animals ingested the first pellet more times and with a shorter average time of ingestion than shy animals, no difference in the second intake, whereas the results for the third were same as those for the first. Shy animals had higher intake of the second pellet. Bold animals explored their environment faster in both challenges, while shy individuals exhibited ability to learn from the challenges imposed in the study.

Thiazolidine derivatives: In vitro toxicity assessment against promastigote and amastigote forms of Leishmania infantum and ultrastructural study.

Neglected diseases, such as Leishmaniasis, constitute a group of communicable diseases that occur mainly in tropical countries. Considered a public health problem with limited treatment. Therefore, there is a need for new therapies. In this sense, our proposal was to evaluate in vitro two series of thiazolidine compounds (7a-7e and 8a-8e) against Leishmania infantum. We performed in vitro evaluations through macrophage cytotoxicity assays (J774) and nitric oxide production, activity against promastigotes and amastigotes, as well as ultrastructural analyzes in promastigotes. In the evaluation of cytotoxicity, the thiazolidine compounds presented CC50 values between 8.52 and 126.83 µM. Regarding the evaluation against the promastigote forms, the IC50 values ranged between 0.42 and 142.43 µM. Compound 7a was the most promising, as it had the lowest IC50. The parasites treated with compound 7a showed several changes, such as cell body shrinkage, shortening and loss of the flagellum, intense mitochondrial edema and cytoplasmic vacuolization, leading the parasite to cell inviability. In assays against the amastigote forms, the compound showed a low IC50 (0.65 µM). These results indicate that compound 7a was efficient for both evolutionary forms of the parasite. In silico studies suggest that the compound has good oral bioavailability. These results show that compound 7a is a potential drug candidate for the treatment of Leishmaniasis.

Decontamination of real urban sewage-comparison between Fenton and electrochemical oxidation.

Advanced oxidation processes have been used for wastewater treatment due to their capacity to reduce the organic loading and for their fast reactions. In this paper, we explore the viability of isolated and sequential use of electrochemical oxidation and Fenton processes into treatment of real raw urban sewage. The electrochemical process was carried out using DSA®-Cl2 electrodes and factorial planning in order to investigate the influence of pH, current density, and electrolyte. Fenton reaction was also used and H2O2 and Fe2+ concentration effects were investigated. The efficiency was estimated by chemical oxygen demand (COD) removal and in the optimized conditions the effluent was characterized by turbidity, suspended/dissolved/total solids, ammonia, chloride ions, free chlorine, nitrite, and potassium analysis and bioassays with Artemia ssp. and Lactuca sativa. The study demonstrated that the use of electrochemical technique followed by Fenton allowed an improvement in the degradation of organic matter and reduction of turbidity and solid content, reaching reductions of 86.8, 96.4, 99.4, 56.1, and 66.7% for COD, turbidity, SS, DS, and TS, respectively. The associated treatment also contributed to the reduction of energy consumption by 74.9%, from the 23.9 kWh m-3 observed during the electrochemical treatment isolated to the 6 kWh m-3 during the associated process. All the treatments presented toxicity reduction, with the electrochemical process achieving the best results.

Pharmacokinetics and cytotoxic study of euphol from Euphorbia umbellata (Bruyns) Pax latex.

BACKGROUND: Medicinal plants are an important source to identify new active pharmaceutical compounds. Traditionally, the sap of Euphorbia umbellata is widely used to treat cancer and inflammatory conditions. These effects have been attributed to the presence of terpenes and phenolic compounds in the extracts of this plant. Euphol, a tetracyclic triterpene alcohol, is one of the major compounds present in Euphorbia species, and some biological activities have been attributed to this compound. PURPOSE: This study aimed to evaluate the in vitro cytotoxicity of euphol against Jurkat, HL-60, K-562, B16F10, and HRT-18 cells lines, as well as the biological stability, distribution, metabolism properties in vitro, and the determination of the concentration of euphol in the plasma and liver of rats. METHODS: The MTT reduction assay was used to evaluate the cytotoxicity of euphol against cancer cell lines, and the selectivity index, the morphology and cell cycle assays to evaluate the death mechanisms in K-562 and B16F10 lineages. UHPLC-MS was applied for the in vivo evaluation of the concentration of euphol in plasma and liver, and in vitro metabolic stability in human liver microsomes and S9 fraction, plasma protein binding, and stability in simulated gastric and intestinal fluids assays. CONCLUSIONS: This study demonstrated that euphol exhibited cytotoxic effects against a variety of cancer cells lines, selectivity against leukemia and possibly, the mechanism involved is apoptosis. The evaluation of stability, distribution, and metabolism properties showed that euphol was unstable in gastric and intestinal fluids, presenting moderate plasma protein binding with two hours elimination half-life and possible phase II liver metabolism. All the results suggested that further studies could be developed to prove the viability of euphol as an anticancer agent.

Therapeutic Response in Adult Patients with Nonsevere Chronic Paracoccidioidomycosis Treated with Sulfamethoxazole-Trimethoprim: A Retrospective Study.

According to the Brazilian Consensus on Paracoccidioidomycosis (PCM), itraconazole is the drug of choice for treatment. However, the combination of sulfamethoxazole and trimethoprim (SMX-TMP) is most commonly used in clinical practice because of its higher availability in the public health services. The aims of this study were to evaluate the therapeutic response of patients with nonsevere chronic PCM to SMX-TMP and highlight the factors related to treatment failure. An adequate therapeutic response was defined as completely improved disease signs and symptoms after medication use for a minimum of 6 months, followed by normalized hematological and biochemical changes, radiological improvements, and negative mycological examination findings. Medical records were analyzed for 244 patients with nonsevere chronic PCM who were treated between 1998 and 2014. In total, 41.9% of the patients had PCM for ≥ 8 months. Seven (2.9%) patients were coinfected with human immunodeficiency virus (HIV). The median (25%, 75% percentiles) treatment duration was 21 (10, 25) months. Adequate treatment adherence was reported by 68.3% of patients. In addition, 73.6% of patients exhibited an adequate therapeutic response. The majority (82.6%) of patients who were treated with SMX-TMP for > 24 months displayed an adequate therapeutic response, and the frequency of adequate therapeutic response gradually decreased as the duration of treatment decreased. Treatment nonadherence (P < 0.001) and PCM-HIV coinfection (P = 0.019) were factors associated with therapeutic failure. The study results support the good efficacy of SMX-TMP. Attention should be given to PCM-HIV coinfection, emphasizing the concern of a higher risk of PCM therapeutic failure in these patients.

Feasible sampling plan for Bemisia tabaci control decision-making in watermelon fields.

BACKGROUND: The silverleaf whitefly Bemisia tabaci is one of the most important pests of watermelon fields worldwide. Conventional sampling plans are the starting point for the generation of decision-making systems of integrated pest management programs. The aim of this study was to determine a conventional sampling plan for B. tabaci in watermelon fields. RESULTS: The optimal leaf for B. tabaci adult sampling was the 6th most apical leaf. Direct counting was the best pest sampling technique. Crop pest densities fitted the negative binomial distribution and had a common aggregation parameter (Kcommon ). The sampling plan consisted of evaluating 103 samples per plot. This sampling plan was conducted for 56 min, costing US$ 2.22 per sampling and with a 10% maximum evaluation error. CONCLUSIONS: The sampling plan determined in this study can be adopted by farmers because it enables the adequate evaluation of B. tabaci populations in watermelon fields (10% maximum evaluation error) and is a low-cost (US$ 2.22 per sampling), fast (56 min per sampling) and feasible (because it may be used in a standardized way throughout the crop cycle) technique. © 2017 Society of Chemical Industry.

Economic injury levels and sequential sampling plans for Frankliniella schultzei in watermelon crops.

BACKGROUND: The thrips Frankliniella schultzei is an important watermelon pest. Nevertheless, economic injury levels and sampling plans for this pest have not yet been determined for this crop. Thus, the objective of the present study was to determine the economic injury levels and develop sequential sampling plans for F. schultzei in conditions of low, medium and high fruit prices. RESULTS: The attack of F. schultzei on watermelon plants at the vegetative stage reduced the crop's productivity, which did not happen at the flowering and fruiting stage. The economic injury levels were 0.09, 0.04 and 0.02 thrips leaf-1 when the watermelon price was low ($US 62.5 t-1 ), medium ($US 140.63 t-1 ) and high ($US 218.75 t-1 ) respectively. The three sequential sampling plans for F. schultzei generated for the economic injury levels resulted in similar and more rapid decisions compared with the conventional plan, especially when the pest density was high. CONCLUSIONS: The three economic injury levels and the sequential sampling plans generated in the present study can be incorporated into integrated pest management programmes for watermelon crops because these plans provide a rapid and adequate control decision for F. schultzei. © 2016 Society of Chemical Industry.

High postprandial triglycerides serum levels: is obesity a good predictor?

The aim of this study was to analyze the correlation between triglyceride (TG) serum levels in obese and non-obese patients in a simulated postprandial state. Both groups showed TG levels < 150 mg/dL when fasting. After 12 h fasting, the subjects ingested a lipid overload diet and blood samples were collected. The variation between fasting and the postprandial TG peak levels were analyzed. The peak of postprandial TG levels occurred 4 h after the lipid overload in both groups. When the subjects were not fasting, the majority of non-obese subjects remained within the range of normal TG values, but the values for the obese group remained elevated. There was a significant correlation between Body Mass Index (BMI) and TG at each time point until 2 h after the meal, but the data did not show a correlation after 3 h. According to the receiver-operating characteristics (ROC) curve, postprandial TG values were not a good predictor of obesity (based on BMI), but they were a predictor of non-obesity. This study reinforces the importance of measuring non-fasting TG levels in obese and non-obese subjects, because some non-obese patients probably had altered fat metabolism, indicating that this examination could be an indicator of metabolic risk.

Assumed white blood cell count of 8,000 cells/µL overestimates malaria parasite density in the Brazilian Amazon.

Quantification of parasite density is an important component in the diagnosis of malaria infection. The accuracy of this estimation varies according to the method used. The aim of this study was to assess the agreement between the parasite density values obtained with the assumed value of 8,000 cells/µL and the automated WBC count. Moreover, the same comparative analysis was carried out for other assumed values of WBCs. The study was carried out in Brazil with 403 malaria patients who were infected in different endemic areas of the Brazilian Amazon. The use of a fixed WBC count of 8,000 cells/µL to quantify parasite density in malaria patients led to overestimated parasitemia and resulted in low reliability when compared to the automated WBC count. Assumed values ranging between 5,000 and 6,000 cells/µL, and 5,500 cells/µL in particular, showed higher reliability and more similar values of parasite density when compared between the 2 methods. The findings show that assumed WBC count of 5,500 cells/µL could lead to a more accurate estimation of parasite density for malaria patients in this endemic region.

Ultrastructural aspects of melatonin cytotoxicity on Caco-2 cells in vitro.

Colon adenocarcinoma is a disease expanding worldwide. Cancer of colon and rectum are among the top ten most insidious types in Brazil. In vitro and in vivo studies have demonstrated the efficacy of the hormone melatonin to prevent and reduce tumor growth. However, there are only few studies addressing the action of melatonin on Caco-2 cells. Thus, the cytotoxic effect of melatonin on the ultrastructure of Caco-2 cells was investigated. The MTT colorimetric method was used to assess the cytotoxicity. A total of 2×10(6)cells/mL were seeded in microplates and incubated at 50, 25, 12.5, 6.25, 3.125, 1.56, 0.78 and 0.0 (control) µg/mL of melatonin. For ultrastructural analysis concentrations with low, medium and high cytotoxicity plus the control were used for ultrastructural analysis. The concentrations 50, 1.56 and 0.78 µg/mL of melatonin showed low, medium and high cytotoxicity, respectively. Ultrastructurally, the control tumor cells were shown to be preserved. Caco-2 cells showed morphological changes at 50 µg/mL of melatonin, with numerous vacuoles, mitochondrial degeneration and reduced glycogen. However, Caco-2 cells also showed altered morphology in treatments at 1.56 and 0.78 µg/mL of melatonin with characteristics of cells in degeneration by the presence of numerous vacuoles, absence of microvilli, mitochondrial degeneration and nuclear fragmentation. Thus, one can infer that concentrations of 1.56 and 0.78 µg/mL of melatonin promote cytotoxicity in Caco-2 cells, which can probably be related to the generation of reactive oxygen species (ROS).

Altered platelet indices as potential markers of severe and complicated malaria caused by Plasmodium vivax: a cross-sectional descriptive study.

BACKGROUND: This study described altered platelet indices in patients with acute malaria caused by Plasmodium vivax and determined whether these alterations are associated with warning signs of severe and complicated malaria. METHODS: A total of 186 patients attending the Malaria Clinic at the University Hospital from the Federal University of Mato Grosso, Brazil, between 2008 and 2013 were included in this study. After parasitological confirmation of exclusive infection by P. vivax, blood cell counts and platelet indices were determined. Disease gravity was evaluated on the basis of classic signs of Plasmodium falciparum severe malaria, including severe anemia, or by changes in serum levels of glucose, bilirubin, aminotransferases and creatinine at the time of the patient's admission. Patients with a longer duration of symptoms or those identified as primo infected were considered potential candidates for evolution into the severe form of malaria. RESULTS: The mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) values exhibited significant variability. A significant inverse relationship was observed between parasitaemia and PCT. Patients with warning signs for evolution into severe disease, with primo infection, or presenting with symptoms for over three days had the highest MPV and PDW. The adjusted analyses showed the presence of warning signs for the development of severe and complicated malaria remained independently linked to elevated MPV and PDW. CONCLUSION: Altered platelet indices should be analysed as potential markers for the severity of malaria caused by P. vivax. Future studies with appropriate methodology for prognostic evaluation could confirm the potential use of these indices in clinical practice.

Pre-clinical anti-inflammatory aspects of a cuisine and medicinal millennial herb: Malva sylvestris L.

Malva sylvestris has been used since ancient times for its emollient, laxative and anti-inflammatory properties, being extensively used as salads, soups and teas. The preset study evaluated the topical anti-inflammatory action of M. sylvestris hydroalcoholic extract (HE) and its compounds in mice ear inflammation caused by 12-O-tetradecanoylphorbol-acetate in mice. The LC-MS analysis of the HE confirmed the presence of scopoletin, quercetin and malvidin 3-glucoside compounds in the HE of M. sylvestris. Topical application of the HE reduced ear oedema, polymorphonuclear cells influx (myeloperoxydase activity and histological analysis) and interleukin-1ß levels in the tissue. The topical application of the compound present in the HE, malvidin 3-glucoside was also able to inhibit ear oedema and leukocytes migration. The other tested compounds, scopoletin, quercetin and malvidin 3,5-glucoside were able to prevent the formation of oedema and cell infiltration, but with less effectiveness when compared to HE and malvidin 3-glucoside. Therefore, these results consistently support the notion that M. sylvestris leaves possesses topical anti-inflammatory activity, the compound malvidin 3-glucoside seems to be major responsible for this effect, with the participation of other anti-inflammatory compounds in the extract. Thus, as recommended by population, M. sylvestris can be used as a future treatment to skin disorders.

Experimental periodontitis promotes transient vascular inflammation and endothelial dysfunction.

OBJECTIVES: This study aimed to evaluate the systemic inflammatory response and cardiovascular changes induced by experimental periodontitis in rats. DESIGN: Experimental periodontitis was induced by placing a cotton ligature around the cervix of both sides of mandibular first molars and maxillary second molars in each male rat. Sham-operated rats had the ligature removed immediately after the procedure. Seven, 14 or 28 days after procedure, the effects of acetylcholine, sodium nitroprusside and phenylephrine were evaluated on blood pressure, aortic rings and isolated and perfused mesenteric bed. The blood was obtained for plasma Interleukin-6 (IL-6), C-reactive protein (CRP) and lipid evaluation. The mesenteric vessels were obtained to evaluate superoxide production and nitric oxide synthase 3 (NOS-3) expression. RESULTS: Ligature induced periodontitis reduced endothelium-dependent vasodilatation, a hallmark of endothelial dysfunction. This effect was associated with an increase in systemic inflammatory markers (IL-6 and CRP), worsens on lipid profile, increased vascular superoxide production and reduced NOS-3 expression. It is interesting to note that many of these effects were transitory. CONCLUSION: Periodontitis induced a transient systemic and vascular inflammation which leads to endothelial dysfunction, an initial step for cardiovascular diseases. Moreover, the animal model of periodontitis used here may represent a valuable tool for studying the relationship between periodontitis and endothelial dysfunction.

Cryptococcus spp isolated from dust microhabitat in Brazilian libraries.

BACKGROUND: The Cryptococcus spp is currently composed of encapsulated yeasts of cosmopolitan distribution, including the etiological agents of cryptococcosis. The fungus are found mainly in substrates of animal and plant origin. Human infection occurs through inhalation of spores present in the environment. METHODS: Eighty-four swab collections were performed on dust found on books in three libraries in the city of Cuiabá, state of Mato Grosso, Brazil. The material was seeded in Sabouraud agar and then observed for characteristics compatible with colonies with a creamy to mucous aspect; the material was then isolated in birdseed (Niger) agar and cultivated at a temperature of 37°C for 5 to 7 days. Identification of isolated colonies was performed by microscopic observation in fresh preparations dyed with India ink, additional tests performed on CGB (L-canavanine glycine bromothymol blue), urea broth, and carbohydrate assimilation tests (auxanogram). RESULTS: Of the 84 samples collected from book dust, 18 (21.4%) were positive for Cryptococcus spp totalizing 41 UFC's. The most frequently isolated species was C. gattii 15 (36.6%); followed by C. terreus, 12 (29.3%); C. luteolus 4 (9.8%); C. neoformans, and C. uniguttulatus 3 (7.3%), and C. albidus and C. humiculus with 2 (4.6%) of the isolates. CONCLUSION: The high biodiversity of the yeasts of the Cryptococcus genus, isolated from different environmental sources in urban areas of Brazil suggests the possibility of individuals whose immune systems have been compromised or even healthy individuals coming into sources of fungal propagules on a daily bases throughout their lives. This study demonstrates the acquisition possible of cryptococcosis infection from dust in libraries.

Histopathology and ultrastructure of midgut of Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) fed Bt-cotton.

The interaction of Cry toxins from Bacillus thuringiensis in the midgut of some insect larvae determines their efficacies as insecticides, due to the expression and availability of sites of action of the toxin in the midgut. Researches point out cases of resistance to Cry toxin due to alterations in the binding sites in columnar cell membrane. We analyzed the effects of Cry1Ac toxin expressed by Bt-cotton plants on Alabama argillacea midgut morphophysiology clarifying in levels of morphological and ultrastructural. Larvae in the 4th instar of A. argillacea after 20 min from ingesting Bt-cotton leaves expressing 0.183 ng of Cry1Ac exhibited ultrastructural and morphological modifications in the columnar cells with significant changes in the mitochondrial polymorphism, cytoplasmic vacuolization, microvillus and basal labyrinth. Expressive morphological alterations were also observed in the goblet cells indicating that the columnar cells are not the only target of the Cry1Ac toxin. The regenerative cells did not modify their structures and exhibited decrease in regeneration capacity. In conclusion, the ingestion of 0.183 ± 0.077 ng of Cry1Ac was enough to promote alterations in the columnar and goblet cells, besides reducing significantly the number of regenerative cells, which may have contributed to larval death. Nevertheless, further studies are necessary to determine the true cause of death.

In vitro and in vivo analyses of the effects of desensitizing agents on dentin permeability and dentinal tubule occlusion.

This study was done to assess the influence of the topical application of two different desensitizing agents on dentin permeability and dentinal tubule occlusion. Twenty-one rats provided 84 teeth: 36 for the in vitro and 48 for the in vivo investigation. The following agents were tested: Group 1, 2% potassium nitrate plus 2% sodium fluoride gel; Group 2, 5% sodium fluoride varnish; Group 3, 3% hydroxyethylcellulose gel (control). Cervical cavities were prepared and EDTA was applied to expose the dentinal tubules. After each treatment, Evans blue dye was applied to the teeth. Dentin permeability, scanning electron microscope (SEM) sections, and energy dispersive X-ray (EDX) were analyzed. One-way ANOVA was used to compare the data. There were significant differences (P < 0.05) among groups for dentin permeability, number of tubules/mm(2), tubule area and tubular diameter. Groups 1 and 2 (both in vitro and in vivo) showed open and partially occluded tubules. Group 3 had the most open tubules. EDX revealed similar composition for both experimental conditions. Within the limits of the study, 2% nitrate potassium plus 2% sodium fluoride gel and 5% fluoride varnish decreased the dentin permeability, resulting in partial tubular occlusion.

Evaluation of the mechanical and chemical control of dental biofilm in patients with Down syndrome.

OBJECTIVE: To evaluate the mechanical and chemical control of dental biofilm in patients with Down syndrome, using different experimental dentifrices. MATERIAL AND METHODS: Forty institutionalized children between ages 7 and 13 years in the mixed dentition phase participated in this study. An experimental cross-over, blind clinical trial was used, having the following protocols: fluoridated dentifrice (protocol G1); fluoridated dentifrice + chlorhexidine (protocol G2); fluoridated dentifrice + chlorhexidine + plaque-disclosing agent (protocol G3); and fluoridated dentifrice + plaque-disclosing agent (protocol G4). Each experimental stage lasted 10 days with a 15-day washout. The evaluated parameters were Plaque Index and gingival bleeding. RESULTS: The initial clinical conditions between each stage were similar. Statistical differences were observed (P < 0.001) for the clinical conditions evaluated before and after the treatments. The dentifrices containing plaque-disclosing agent, irrespective of their association with chlorhexidine, produced a greater reduction in the final plaque index. As for gingival bleeding, the dentifrice containing erythrosine and the one containing chlorhexidine produced similar results. The dentifrice containing an association of chlorhexidine and erythrosine gave the best results. CONCLUSION: With the methodology employed, it was possible to conclude that the combination of drugs (chlorhexidine, fluorine and erythrosine) within one dentifrice can be useful in controlling dental biofilm and in the reduction of gingival bleeding.

Ultrastructure of the Alabama argillacea (Hübner) (Lepidoptera: Noctuidae) midgut.

The insect midgut has ultimately been the focus of researches tempting to control insect pests because alterations in the insect gut may affect not only its development, but also physiological events such as nutrient absorption and transformation. The objective of the present work was to describe morphologically, histochemically, and ultrastructurally the larva midgut of Alabama argillacea (Hübner) (Lepidoptera: Noctuidae), a cotton key pest in Brazil. Light and electronic transmission microscopy was used to obtain images from midgut sections of late fourth-instar larvae of A. argillacea. In general, the morphology, histochemistry, and ultrastructure characteristics of A. argillacea midgut follow that described in the literature for other lepidopteran species. However, the results showed a mitochondrial polymorphism and branched microvilli, which suggest an ultrastrucutural and physiological modification possibly associated with a high absorption and secretion activity by the columnar cells of this species. This intense activity may favor a faster response related to the action of ingested microbial agents and/or toxins, and can explain the high susceptibility of A. argillacea to the agents of control such as the toxin of Bacillus thuringiensis.