Topographical, diametral, and quantitative analysis of dentin tubules in the root canals of human and bovine teeth

The aim of this study was to evaluate the number and the diameter of dentin tubules in root canals, in the cervical, middle, and apical thirds, of human and bovine teeth. Twenty-four single-rooted, human premolars were divided into four groups (n = 6): GH1, 10 to 15 years; GH2, 16 to 30 years; GH3, 31 to 45 years; and GH4, 46 to 80 years; and 24 bovine incisors were divided into four groups (n = 6): GB1, central; GB2, lateral first; GB3, lateral second; and GB4, lateral third. The crowns were removed from the specimens, which were then debrided, sectioned longitudinally in the vestibular-lingual direction, and submitted to ultrasonic cleaning. Scanning electron microscopic evaluations were made with 1,000x and 5,000x magnification. According to the root thirds, statistically significant differences were found both for the number and the diameter of dentin tubules, with the cervical third presenting the highest mean values for both specimen types. As regards the number of dentin tubules, it was observed that the bovine specimens presented a significantly higher mean value than the human specimens; this difference was not observed when the diameters of the two types were compared.

Antimicrobial activity and phytochemical analysis of crude extracts and essential oils from medicinal plants

We aimed to establish a phytochemical analysis of the crude extracts and performed GC-MS of the essential oils (EOs) of Eugenia uniflora L. (Myrtaceae) and Asteraceae species Baccharis dracunculifolia DC, Matricaria chamomilla L. and Vernonia polyanthes Less, as well as determining their antimicrobial activity. Establishment of the minimal inhibitory concentrations of the crude extracts and EOs against 16 Staphylococcus aureus and 16 Escherichia coli strains from human specimens was carried out using the dilution method in Mueller-Hinton agar. Some phenolic compounds with antimicrobial properties were established, and all EOs had a higher antimicrobial activity than the extracts. Matricaria chamomilla extract and E. uniflora EO were efficient against S. aureus strains, while E. uniflora and V. polyanthes extracts and V. polyanthes EO showed the best antimicrobial activity against E. coli strains. Staphylococcus aureus strains were more susceptible to the tested plant products than E. coli, but all natural products promoted antimicrobial growth inhibition.

Sinergismo entre óleos essenciais e drogas antimicrobianas sobre linhagens de Staphylococcus aureus e Escherichia coli isoladas de casos clínicos humanos

Estudos com plantas e utilização em terapias combinatórias têm sido estimulados. Verificou-se as possíveis interações entre óleos essenciais de plantas [canela (Cinnamomum zeylanicum Blume Lauraceae), capim-cidreira (Cymbopogon citratus (DC.) Stapf, Poaceae), hortelã-pimenta (Mentha piperita L. Lamiaceae), gengibre (Zingiber officinale Roscoe Zingiberaceae), cravo-da-índia (Caryophillus aromaticus L. Myrtaceae) e alecrim (Rosmarinus officinalis L. Lamiaceae)] combinados a oito drogas antimicrobianas frente a doze linhagens de Staphylococcus aureus e doze de Escherichia coli isoladas de humanos. Após determinação da Concentração Inibitória Mínima (CIM) para os óleos pelo método da diluição foram realizados ensaios para verificação de sinergismo entre os óleos essenciais e os antimicrobianos pela metodologia de Kirby & Bauer. S. aureus foi mais suscetível às interações óleos e drogas, tendo o óleo de capim cidreira apresentado sinergismo com as oito drogas testadas, seguido pelo óleo de hortelã com sete drogas. Nos ensaios com E. coli, houve sinergismo apenas para os óleos de alecrim (três drogas) e capim-cidreira (duas drogas). Não ocorreram casos de antagonismo e os resultados de sinergismo foram influenciados pelos microrganismos estudados.

Molecular investigation of zoonotic genotypes of Giardia intestinalis isolates in humans, dogs and cats, sheep, goats and cattle in Araçatuba (Sãoo Paulo State, Brazil) by the analysis of beta-giardin gene fragments

In the period from July 2009 to October 2010, fecal samples from 61 animals and 154 humans from the municipality of Aracatuba (São Paulo State, Brazil) were studied. Fecal samples from animals were collected in the Municipal Animal Shelter and the Veterinary Hospital of the Universidade Estadual Paulista. Human fecal specimens were collected in playschools in the outskirts of the city by the private network of clinical analysis laboratories of the municipal. Diagnosis was done by optical microscopy using the Faust and Hoffmann, Pons and Janer techniques. The genotypes of Giardia intestinalis were characterized by PCR-RFLP and confirmed by sequencing the ß-giardin gene. Human specimens were positive in 25.3% (39/154) of the cases with 26.8% (36/134) of the specimens from children and 15% (3/20) from adults being positive. The frequency of G. intestinalis among the animals was 23.0% (14/61). A total of 32 isolates of G. intestinalis obtained from human feces and six from dogs and cats were characteristic of the A genotype (AI and AII/AIII). The results of this study in respect to frequency of giardiasis are similar to reported in most studies in Brazil. The prevalence observed in animal populations conforms to worldwide infection rates. G. intestinalis genotypes considered zoonotic were detected in both pets and humans from the city of Aractuba, suggesting a possible zoonotic transmission of the parasite in the northwestern region of São Paulo State. The absence of these genotypes in farm animals may imply that they are not involved in the chain of transmission to humans in this region.

In vitro antibacterial and chemical properties of essential oils including native plants from Brazil against pathogenic and resistant bacteria

The antimicrobials products from plants have increased in importance due to the therapeutic potential in the treatment of infectious diseases. Therefore, we aimed to examine the chemical characterisation (GC-MS) of essential oils (EO) from seven plants and measure antibacterial activities against bacterial strains isolated from clinical human specimens (methicillin-resistant Staphylococcus aureus (MRSA) and sensitive (MSSA), Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhimurium) and foods (Salmonella Enteritidis). Assays were performed using the minimal inhibitory concentration (MIC and MIC90%) (mg/mL) by agar dilution and time kill curve methods (log CFU/mL) to aiming synergism between EO. EO chemical analysis showed a predominance of terpenes and its derivatives. The highest antibacterial activities were with Cinnamomun zeylanicum (0.25 mg/mL on almost bacteria tested) and Caryophyllus aronzaticus EO (2.40 mg/mL on Salmonella Enteritidis), and the lowest activity was with Eugenia uniflora (from 50.80 mg/mL against MSSA to 92.40 mg/mL against both Salmonella sources and P aeruginosa) EO. The time kill curve assays revealed the occurrence of bactericide synergism in combinations of C. aromaticus and C. zeylanicum with Rosmarinus. officinalis. Thus, the antibacterial activities of the EO were large and this can also be explained by complex chemical composition of the oils tested in this study and the synergistic effect of these EO, yet requires further investigation because these interactions between the various chemical compounds can increase or reduce (antagonism effect) the inhibitory effect of essential oils against bacterial strains.

Synergism of crude extracts and essential oils from medicinal plants with antimicrobial drugs

The emergence of resistant strains to conventional antimicrobial drugs has been constant as well as research aimed new alternatives of antibacterial agents. Therefore, considering that natural products have been an important potential source of new antimicrobial drugs, aim to verify the synergism by disk and time kill curve method between antimicrobials (extracts-Ext. and essential oils-EO) from four plant and eight antimicrobial drugs against Staphylococcus aureus and Escherichia coli strains from human specimens. The S. aures strains were highly susceptible with all plant antimicrobials (eg., 1.24 mg/ml with Vernonia polyanthes Ext. and 2.21 mg/ml with Eugenia uniflora EO for the Minimal Inhibitory Concentration-MIC). According disk method, the Bacharis dracunculifolia and V. polyanthes EO had synergism with all eight tested drugs while only Matricaria chamomilla Ext. showed synergism against S. aureus. The synergism was found with V. polyanthes and E. uniflora Ext. while M. chamomilla Ext. had antagonism against E. coli strains. By time kill curve, the bacterial growth inhibition was superior when drugs were tested alone and the synergism effect also was verified. The antagonism effect was detected only for E. coli strains and only with Ext. Results indicated the potential use of these products as coadjutants during treatment of infectious diseases.

Fecal specimens preparation methods for PCR diagnosis of human taeniosis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Expression of nonclassical molecule human leukocyte antigen-G in oral lesions

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Upregulation of soluble and membrane-bound human leukocyte antigen G expression is primarily observed in the milder histopathological stages of chronic hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection is a worldwide health problem that may evolve to cirrhosis and hepatocellular carcinoma. Incompletely understood immune system mechanisms have been associated with impaired viral clearance. The nonclassical class I human leukocyte antigen G (HLA-G) molecule may downregulate immune system cell functions exhibiting well-recognized tolerogenic properties. HCV genotype was analyzed in chronic HCV-infected patients. Because HLA-G expression may be induced by certain viruses, we evaluated the presence of HLA-G in the liver microenvironment obtained from 89 biopsies of patients harboring chronic HCV infection and stratified according to clinical and histopathological features. Overall, data indicated that HCV genotype 1 was predominant, especially subgenotype 1a, with a prevalence of 87%. HLA-G expression was observed in 45(51%) liver specimens, and it was more frequent in milder stages of chronic hepatitis (67.4%) than in moderate (27.8%; p = 0.009) and severe (36.0%; p = 0.021) stages of the disease. Altogether, these results suggest that the expression of HLA-G in the context of HCV is a complex process modulated by many factors, which may contribute to an immunologic environment favoring viral persistence. However, because the milder forms predominantly expressed HLA-G, a protective role of this molecule may not be excluded. (C) 2012 American Society for Histocompatibility and Immunogenetics. Published by Elsevier B.V. All rights reserved.

Mercury and DDT exposure risk to fish-eating human populations in Amazon

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Taenia saginata: polymerase chain reaction for taeniasis diagnosis in human fecal samples

The taeniasis-cysticercosis complex is a zoonosis of great medical and economic importance where humans play an important role as the carrier of adult stage of Taenia solium and Taenia saginata. This paper describes PCR standardization that can be applied in human fecal samples for taeniasis diagnosis. DNA extraction was achieved with DNAzol reagent, after egg disruption with glass beads. DNA prepared from fecal specimens was first purified and PCR amplified generating fragments of 170 and 600 bp. The assay described herein provides an important tool for T saginata identification in human fecal samples. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Effect of salivary stimulation on erosion of human and bovine enamel subjected or not to subsequent abrasion: An in situ/ex vivo study

This in situ/ex vivo study evaluated whether saliva stimulated by chewing gum could prevent or reduce the wear and the percent change in microhardness (%SMH) of bovine and human enamel submitted to erosion followed by brushing abrasion immediately or after 1 h. During 2 experimental 7-day crossover phases, 9 previously selected volunteers wore intraoral palatal devices, with 12 enamel specimens (6 human and 6 bovine). In the first phase, the volunteers immersed the device for 5 min in 150 ml of cola drink, 4 times per day (at 8, 12, 16 and 20 h). Immediately after the immersions, no treatment was performed in 4 specimens, 4 other specimens were immediately brushed (0 min) using a fluoride dentifrice, and the device was replaced into the mouth. After 60 min, the remaining 4 specimens were brushed. In the second phase, the procedures were repeated, but after the immersions, the volunteers stimulated the salivary flow rate by chewing a sugar-free gum for 30 min. Changes in wear and %SMH were measured. ANOVA and Tukey's test showed statistical differences (p < 0.05) for the following comparisons. The chewing gum promoted less wear and %SMH. A decreasing %SMH and an increasing enamel wear were observed in the following conditions: erosion only, 60 min and 0 min. The human enamel presented greater %SMH and less wear compared to bovine enamel. The data suggest that the salivary stimulation after an erosive or erosive/abrasive attack can reduce the dental wear and the %SMH.

Cross-Sectional Microhardness of Human Enamel Subjected to Erosive, Cariogenic or Combined Erosive/Cariogenic Challenges

This in situ study evaluated the interaction between caries and erosion processes. In the first phase, enamel specimens were subjected to erosion without dental plaque (EO) or to erosion with plaque (EP); in the second phase, they were subjected to erosion plus cariogenic challenge (EC) or cariogenic challenge (CO), both with plaque accumulation. Cross-sectional hardness data (10-330 mu m depth) were tested using ANOVA (alpha = 0.05). EO and EP showed surface softening to 10 mu m depth. CO and EC produced subsurface lesions, of similar depth (up to 220 mu m), with CO showing higher integrated loss of hardness than EC, indicating that cariogenic and erosive challenges did not have an additive effect. Copyright (C) 2010 S. Karger AG, Basel

Correlation between koilocytes and human papillomavirus detection by PCR in oral and oropharynx squamous cell carcinoma biopsies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)