A enxurrada de 11 de Setembro de 1813 nas freguesias de São Bartolomeu, Santa Bárbara e São Jorge das Doze Ribeiras (Terceira)

[...] As catástrofes provenientes do rigor de intempéries sempre assolaram com alguma regularidade o quotidiano das populações da ilha Terceira, espalhando a angústia e a miséria entre os moradores dos lugares afectados. A comprová-lo, em 11 de Setembro de 1813, as freguesias de S. Bartolomeu, Santa Bárbara e S. Jorge das Doze Ribeiras foram atingidas por enxurradas, em virtude de ter havido «... na serra de Santa Barbara grande enchente das ribeiras, procedida de uma tromba d’agoa que sobre ella caiu... ». Aágua transbordou das ribeiras e ramificou-se em várias correntes que percorreram grandes distâncias e causaram prejuízos consideráveis não apenas em «... casas que levou, como na gente, nos gados e campos, cujas paredes ficaram arrasadas e os cerrados areados...». [...

Antimicrobial photodynamic therapy alone or in combination with antibiotic local administration against biofilms of Fusobacterium nucleatum and Porphyromonas gingivalis

Antimicrobial photodynamic therapy (aPDT) kills several planktonic pathogens. However, the susceptibility of biofilm-derived anaerobic bacteria to aPDT is poorly characterized. Here, we evaluated the effect of Photodithazine (PDZ)-mediated aPDT on Fusobacterium nucleatum and Porphyromonas gingivalis biofilms. In addition, aPDT was tested with metronidazole (MTZ) to explore the potential antimicrobial effect of the treatment. The minimum inhibitory concentration (MIC) of MTZ was defined for each bacterial species. Single-species biofilms of each species were grown on polystyrene plates under anaerobic conditions for five days. aPDT was performed by applying PDZ at concentrations of 50, 75 and 100 mg/L, followed by exposure to 50 J/cm2 LED light (660 nm) with or without MTZ. aPDT exhibited a significant reduction in bacterial viability at a PDZ concentration of 100 mg/L, with 1.12 log10 and 2.66 log10 reductions for F. nucleatum and P. gingivalis in biofilms, respectively. However, the antimicrobial effect against F. nucleatum was achieved only when aPDT was combined with MTZ at 100× MIC. Regarding P. gingivalis, the combination of PDZ-mediated aPDT at 100 mg/L with MTZ 100× MIC resulted in a 5 log10 reduction in the bacterial population. The potential antimicrobial effects of aPDT in combination with MTZ for both single pathogenic biofilms were confirmed by live/dead staining. These results suggest that localized antibiotic administration may be an adjuvant to aPDT to control F. nucleatum and P. gingivalis biofilms

Análise quantitativa dos tecidos gengivais de ratos tratados com fenitoína e ciclosporina

Os aumentos gengivais podem ser decorrentes de reações teciduais a estímulos idiopáticos, patológicos e farmacológicos. O objetivo desse trabalho foi avaliar morfometricamente e estereologicamente a ação da fenitoína (Fen) e ciclosporina (CsA) sobre os tecidos gengivais de ratos. Dez ratos receberam, por via intraperitonial, Fen na dose inicial de 2 mg/kg de peso corporal/dia, aumentando 2 mg a cada duas semanas, durante 60 dias. em outros 10 ratos, administraram-se, por via subcutânea, 10mg/kg de peso corporal/dia de CsA, durante o mesmo período do grupo anterior. Os valores morfométricos e estereométricos dos tecidos gengivais dos ratos tratados com CsA foram significativamente maiores quando comparado com os valores dos tecidos gengivais do grupo tratado com Fen. Esses resultados sugerem que a CsA na dose utilizada é mais eficaz no desenvolvimento do aumento gengival em ratos, podendo estar atuando na proliferação de fibroblastos e no desequilíbrio fisiológico da síntese de fibras colágenas.Reactions to a number of idiopathic, pathological and pharmacological stimuli may result in overgrowth of gingiva, whose mechanisms have not been established yet. The aim of the present work was to evaluate morphometrically and stereologically the effect of phenytoin (PHT) and cyclosporine (Cs) on the gingival tissues of rats. Ten rats received daily IP injection of PHT, 2 mg/kg of body weight/day, which was increased in 2 mg at each two weeks, during 60 days. Ten rats received 10 mg/kg of body weight/day of Cs, subcutaneously, during the same period of the previous group. All rats treated with Cs developed gingival overgrowth, with increased thickness of the epithelium, height and wideness of connective tissues, as well as, increased density of fibroblasts and collagen fibers, when compared with the rats treated with PHT and with the control. These results suggest that Cs, in the used dose, is more efficient in the development of gingival overgrowth in rats. Cs-induced gingival overgrowth is a tissue with an altered composition, characterized by increasing of the density of fibroblasts and by physiologic unbalance of collagen synthesis

New Strategies on Molecular Biology Applied to Microbial Systematics

Systematics is the study of diversity of the organisms and their relationships comprising classification, nomenclature and identification. The term classification or taxonomy means the arrangement of the organisms in groups (rate) and the nomenclature is the attribution of correct international scientific names to organisms and identification is the inclusion of unknown strains in groups derived from classification. Therefore, classification for a stable nomenclature and a perfect identification are required previously. The beginning of the new bacterial systematics era can be remembered by the introduction and application of new taxonomic concepts and techniques, from the 50’s and 60’s. Important progress were achieved using numerical taxonomy and molecular taxonomy. Molecular taxonomy, brought into effect after the emergence of the Molecular Biology resources, provided knowledge that comprises systematics of bacteria, in which occurs great evolutionary interest, or where is observed the necessity of eliminating any environmental interference. When you study the composition and disposition of nucleotides in certain portions of the genetic material, you study searching their genome, much less susceptible to environmental alterations than proteins, codified based on it. In the molecular taxonomy, you can research both DNA and RNA, and the main techniques that have been used in the systematics comprise the build of restriction maps, DNA-DNA hybridization, DNA-RNA hybridization, sequencing of DNA sequencing of sub-units 16S and 23S of rRNA, RAPD, RFLP, PFGE etc. Techniques such as base sequencing, though they are extremely sensible and greatly precise, are relatively onerous and impracticable to the great majority of the bacterial taxonomy laboratories. Several specialized techniques have been applied to taxonomic studies of microorganisms. In the last years, these have included preliminary electrophoretic analysis of soluble proteins and isoenzymes, and subsequently determination of deoxyribonucleic acid base composition and assessment of base sequence homology by means of DNA-RNA hybrid experiments beside others. These various techniques, as expected, have generally indicated a lack of taxonomic information in microbial systematics. There are numberless techniques and methodologies that make bacteria identification and classification study possible, part of them described here, allowing establish different degrees of subspecific and interspecific similarity through phenetic-genetic polymorphism analysis. However, was pointed out the necessity of using more than one technique for better establish similarity degrees within microorganisms. Obtaining data resulting from application of a sole technique isolatedly may not provide significant information from Bacterial Systematics viewpoin

Quantitative analysis of gingival tissues of rats treated with phenytoin and cyclosporine

Os aumentos gengivais podem ser decorrentes de reações teciduais a estímulos idiopáticos, patológicos e farmacológicos. O objetivo desse trabalho foi avaliar morfometricamente e estereologicamente a ação da fenitoína (Fen) e ciclosporina (CsA) sobre os tecidos gengivais de ratos. Dez ratos receberam, por via intraperitonial, Fen na dose inicial de 2 mg/kg de peso corporal/dia, aumentando 2 mg a cada duas semanas, durante 60 dias. em outros 10 ratos, administraram-se, por via subcutânea, 10mg/kg de peso corporal/dia de CsA, durante o mesmo período do grupo anterior. Os valores morfométricos e estereométricos dos tecidos gengivais dos ratos tratados com CsA foram significativamente maiores quando comparado com os valores dos tecidos gengivais do grupo tratado com Fen. Esses resultados sugerem que a CsA na dose utilizada é mais eficaz no desenvolvimento do aumento gengival em ratos, podendo estar atuando na proliferação de fibroblastos e no desequilíbrio fisiológico da síntese de fibras colágenas.Reactions to a number of idiopathic, pathological and pharmacological stimuli may result in overgrowth of gingiva, whose mechanisms have not been established yet. The aim of the present work was to evaluate morphometrically and stereologically the effect of phenytoin (PHT) and cyclosporine (Cs) on the gingival tissues of rats. Ten rats received daily IP injection of PHT, 2 mg/kg of body weight/day, which was increased in 2 mg at each two weeks, during 60 days. Ten rats received 10 mg/kg of body weight/day of Cs, subcutaneously, during the same period of the previous group. All rats treated with Cs developed gingival overgrowth, with increased thickness of the epithelium, height and wideness of connective tissues, as well as, increased density of fibroblasts and collagen fibers, when compared with the rats treated with PHT and with the control. These results suggest that Cs, in the used dose, is more efficient in the development of gingival overgrowth in rats. Cs-induced gingival overgrowth is a tissue with an altered composition, characterized by increasing of the density of fibroblasts and by physiologic unbalance of collagen synthesis

Conversion of immunosuppressive monotherapy from cyclosporin A to tacrolimus reverses bone loss in rats

Tacrolimus is used for transplant patients with refractory graft rejection and those with intolerance to cyclosporin (CsA), without the disfiguring adverse effects frequently attributed to CsA therapy. Since we have shown that CsA-associated bone loss can also affect alveolar bone, the purpose of this study was to evaluate the effects of conversion of monotherapy from CsA to tacrolimus on alveolar bone loss in rats. Groups of rats were treated with either CsA (10 mg/kg/day, s.c.), tacrolimus (I mg/kg/day, s.c.), or drug vehicle for 60 and 120 days, and an additional group received CsA for 60 days followed by conversion to tacrolimus for a further 60-day period. Bone-specific alkaline phosphatase (BALP), tartrate-resistent acid phosphatase (TRAP-5b), calcium (Ca2+), interleukin (IL)-1 beta, IL-6, and tumor necrosis factor alpha (TNF-alpha) concentrations were evaluated in the serum. Analyses of bone volume, bone surface, number of osteblasts, and osteoclasts were performed. Treatment with CsA for either 60 or 120 days was associated with bone resorption, represented by lower bone volume and increased number of osteoclasts; serum BALP, TRAP-5b, IL-1 beta, IL-6, and TNF-alpha were also higher in these animals. After conversion from CsA to tacrolimus, all the altered serum markers returned to control values in addition to a significant increase of bone volume and a lower number of osteoclasts. This study shows that conversion from CsA to tacrolimus therapy leads to a reversal of the CsA-induced bone loss, which can probably be mediated by downregulation of IL-1 beta, IL-6, and TNF-alpha production

Staphylococcus Aureus Contamination in a Pediatric Dental Clinic

Staphylococcus aureus strains can be disseminated during dental treatment and occasionally lead to contamination and infection of patients and dentists. The objective of this study was to determine the frequency and compare the number of S.aureus colonies isolated from the nose, hands and tongue of students and patients, as well as from the clinical environment, before and after dental treatment. Staphylococcus species were isolated from the tongue, nose and hands of 30 students and 30 patients and from the environment of a Pediatric Dentistry Clinic. The samples were incubated in SMA plates at 37 degrees C for 48 hours. Results: The colonies that showed the presence of mannitol fermentation were collected as identification for Staphylococcus aureus, using CHROMagar and the coagulase test. The highest amount of S.aureus was found in the nose and tongue of children. In relation to dental students, more contamination was observed on gloved hands, followed by the tongue and hands without gloves, before clinical attendance. At the end of dental treatment, S. aureus colonies isolated from the gloved hands of students decreased significantly. Considering the clinical environment, the most contaminated areas were the auxiliary table and the storeroom, which was located at the center of the clinic. Conclusion: The dental clinic can be considered an environment for S. aureus cross-transmission. Preventative measures should be used to avoid the dissemination of pathogenic microorganisms.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

In vitro effect of low-level laser therapy on typical oral microbial biofilms

The aim of this study was to evaluate the effect of specific parameters of low-level laser therapy (LLLT) on biofilms formed by Streptococcus mutans, Candida albicans or an association of both species. Single and dual-species biofilms - SSB and DSB - were exposed to laser doses of 5, 10 or 20 J/cm 2 from a near infrared InGaAsP diode laser prototype (LASERTable; 780 ± 3 nm, 0.04 W). After irradiation, the analysis of biobilm viability (MTT assay), biofilm growth (cfu/mL) and cell morphology (SEM) showed that LLLT reduced cell viability as well as the growth of biofilms. The response of S. mutans (SSB) to irradiation was similar for all laser doses and the biofilm growth was dose dependent. However, when associated with C. albicans (DSB), S. mutans was resistant to LLLT. For C. albicans, the association with S. mutans (DSB) caused a significant decrease in biofilm growth in a dose-dependent fashion. The morphology of the microorganisms in the SSB was not altered by LLLT, while the association of microbial species (DSB) promoted a reduction in the formation of C. albicans hyphae. LLLT had an inhibitory effect on the microorganisms, and this capacity can be altered according to the interactions between different microbial species