Antimicrobial resistance profile of Aeromonas spp. isolated from asymptomatic Colossoma macropomum cultured in the Amazonas State, Brazil.

Bacterial diseases are important factors that limit productivity in aquaculture. To reduce negative economic impacts, fish farmers use antimicrobials, often indiscriminately, and this action has led to bacterial resistance to drugs. The objectives of this study were to isolate and identify the main putative pathogenic bacterial species in tambaqui (Colossoma macropomum), establish the profile of resistance to antimicrobials by the methods of disc diffusion, and determine the minimum inhibitory concentration (MIC) values. Two hundred and ninety asymptomatic fish were collected between March and November 2015 from ten fish farms in the Amazonas state (Brazil). Of the total strains recovered from tambaqui, seven were identified as Aeromonas spp. by sequencing the 16S rRNA gene. These seven isolates showed resistance to ampicillin, 28% to erythromycin, and 28% to sulfonamide. Additionally, the seven isolates showed a MIC higher than the range evaluated for amoxicillin, penicillin, novobiocin, tylosin tartrate, and clindamycin, and 85% showed resistance to erythromycin. The results of this study indicate the need to increase the awareness of fish farmers and, most importantly, the government, about the lack of drug regulations for use in aquaculture, and good management practices, so the indiscriminate prophylactic and systemic use of antimicrobials be inhibited.

Myelin imaging measures as predictors of cognitive impairment in MS patients: A hybrid PET-MRI study.

BACKGROUND: Cognitive impairment is one of the concerns of Multiple Sclerosis (MS) and has been related to myelin loss. Different neuroimaging methods have been used to quantify myelin and relate it to cognitive dysfunctions, among them Magnetization Transfer Ratio (MTR), Diffusion Tensor Imaging (DTI), and, more recently, Positron Emission Tomography (PET) with 11C-PIB. OBJECTIVE: To investigate different myelin imaging modalities as predictors of cognitive dysfunction. METHODS: Fifty-one MS patients and 24 healthy controls underwent clinical and neuropsychological assessment and MTR, DTI (Axial Diffusion-AD and Fractional Anisotropy-FA maps), and 11C-PIB PET images in a PET/MR hybrid system. RESULTS: MTR and DTI(FA) differed in patients with or without cognitive impairment. There was an association of DTI(FA) and DTI(AD) with cognition and psychomotor speed for progressive MS, and of 11C-PIB uptake and MTR for relapsing-remitting MS. MTR in the Thalamus (ß= -0.51, p = 0.021) and Corpus Callosum (ß= -0.24, p = 0.033) were predictive of cognitive impairment. DTI-FA in the Caudate (ß= -26.93, p = 0.006) presented abnormal predictive result. CONCLUSION: Lower myelin content by 11C-PIB uptake was associated with worse cognitive status. MTR was predictive of cognitive impairment in MS.

In vitro effect of toothpaste with low fluoride combined with sodium trimetaphosphate on dentine erosion.

PURPOSE: This study sought to evaluate in vitro the effect of a dentifrice containing sodium trimetaphosphate (TMP) combined or not with low fluoride (500 ppm NaF) on dentine erosion of intrinsic origin. METHODS: Human root dentine blocks were selected based on surface microhardness and randomly allocated into five groups (n = 12): negative control (0 ppm F; no TMP); F500 (500 ppm NaF); F1500 (1500 ppm NaF-positive control); TMP (1% TMP); and F + TMP (500 ppm NaF + 1% TMP). The blocks were submitted to erosion cycles (3 ×/day) for 3 days (0.01 M HCl, pH 1.5-30 s), treatment (1 min-1:3 p/p dentifrice/distilled water) and remineralization (artificial saliva/120 min). Dentine alterations were determined according to the percentage of microhardness loss (%HL), surface loss (SL) and surface analysis by scanning electron microscopy. The data were analyzed using one-way ANOVA (p < 0.05). RESULTS: The values of SL and %HL in each group were, respectively: negative control (1.36 ± 0.36; 57.29 ± 14.14), F500 (1.46 ± 0.28; 65.66 ± 5.11), F1500 (1.52 ± 0.36; 61.66 ± 5.15), TMP (1.45 ± 0.45; 62.08 ± 3.83) and F + TMP (1.38 ± 0.42; 63.38 ± 6.47). There was no statistically significant difference in all the parameters (p = 0.873 and p = 0.152). CONCLUSION: The dentifrices containing TMP combined or not with fluoride were not able to prevent dentine erosion.

Impact of nutritional status according to GLIM criteria on the risk of incident frailty and mortality in community-dwelling older adults.

BACKGROUND & AIMS: Poor nutritional status leads to multiple adverse outcomes, but few studies have assessed its role as a risk factor for incident frailty and death in community-dwelling older adults. Hence, the aim of this paper is to assess the role of nutritional status using the Global Leadership Initiative on Malnutrition (GLIM) criteria in the risk of frailty and mortality in Spanish community-dwelling older adults. METHODS: We used data from two waves (waves 2 (2011-2013) and 3 (2015-2017)) from the Toledo Study of Healthy Ageing, which is an observational, prospective cohort (average follow-up = 3.18 years) of 1660 older (≥65 years) adults living in the community. Nutritional status categories were defined according to the GLIM criteria, which uses a two-step approach. First, screening for malnutrition risk. Once positive, individuals were classified as malnourished according to some phenotypic (body mass index, grip strength and unintentional weight loss) and etiologic (disease burden/inflammation and reduced food intake or assimilation) criteria. Frailty was assessed using both the Frailty Index (FI) and Frailty Trait Scale (FTS). Mortality data was obtained through the National Death Index. RESULTS: From the 1660 older adults, 248 participants (14.04%) were classified as 'at malnutrition risk' (AMR) and 209 (12.59%) as malnourished (MN). AMR and MN subjects were older and with worse functional status (frailer). Adjusted cross-sectional analysis showed an association between nutritional status and frailty by both FI and FTS. Adjusted longitudinal analyses showed that AMR was associated with higher risk of frailty, using both the FTS (OR: 1.262; 95% CI: 1.078-1.815) and the FI (OR: 1.116; 95% CI: 1.098-1.686), while being malnourished was associated with higher mortality risk (OR: 1.748; 95% CI: 1.073-2.849), but not with incident frailty at follow-up period. CONCLUSIONS: Nutritional status, assessed through GLIM, predicts in a dose-dependent manner the risk of frailty and death. Being at malnutrition risk predicts the risk of becoming frail at follow-up period, whereas being malnourished predicts mortality. These findings highlight the importance of assessing the nutritional status of community-dwelling older adults to identify the ones at risk of developing frailty or death and inform targeted nutrition-focused interventions.

Low Protein Intake Irrespective of Source is Associated with Higher Mortality Among Older Community-dwelling Men.

OBJECTIVES: Our aim was to determine the association between protein intake (overall and by source) and all-cause and cause-specific mortality among older men. DESIGN: Prospective cohort study. SETTING: 5790 ambulatory community-dwelling older men from multicenter Osteoporotic Fractures in Men (MrOS) study. MEASUREMENTS: Total energy and protein intake, and protein intake by source (dairy, non-dairy animal, plant) were assessed using a 69-item food frequency questionnaire. We included up to 10-year follow-up with adjudicated cardiovascular, cancer and other mortality outcomes. We used time-to-event analysis with protein exposures, mortality outcome, and adjusted for possible confounders including age, center, education, race, smoking, alcohol use, physical activity, weight, total energy intake (TEI), and comorbidities. Hazard ratios were expressed per each unit=2.9% TEI decrement for all protein intake variables. RESULTS: The mean (SD) baseline age of 5790 men was 73.6 (5.8) y. There were 1611 deaths and 211 drop-outs prior to 10 years, and 3868 men who were alive at the 10-year follow-up. The mean (SD) total protein intake was 64.7 (25.8) g/d, while the mean (SD) intake expressed as percent of total energy intake (%TEI) was 16.1 (2.9) %TEI. Lower protein intake was associated with an increased risk of death, with unadjusted HR=1.11 (95% CI: 1.06, 1.17) and adjusted HR=1.09 (95% CI: 1.04, 1.14) and the associations for protein intake by source were similar. The adjusted HR for cancer mortality was HR=1.13 (95% CI: 1.03, 1.25) while the association for CVD mortality was HR=1.08 (95% CI: 0.99, 1.18). CONCLUSIONS: Low protein intake, irrespective of source, was associated with a modest increase in risk of all-cause and cause-specific mortality among older men. Special consideration should be given to level of protein intake among older adults.

Predictor Biomarkers of Nonelective Hospital Readmission and Mortality in Malnourished Hospitalized Older Adults.

BACKGROUND: 90-day mortality and rehospitalizations are important hospital quality metrics. Biomarkers that predict these outcomes among malnourished hospitalized patients could identify those at risk and help direct care plans. OBJECTIVES: To identify biomarkers that predict 90-day (primary) and 30-day (secondary) mortality or nonelective rehospitalization. DESIGN AND PARTICIPANTS: An analysis of the ability of biomarkers to predict 90- and 30-day mortality and rehospitalization among malnourished hospitalized patients. SETTING: 52 blood biomarkers were measured in 193 participants in NOURISH, a randomized trial that determined the effects of a nutritional supplement on 90-day readmission and death in patients >65 years. Composite outcomes were defined as readmission or death over 90-days or 30-days. Univariate Cox Proportional Hazards models were used to select best predictors of outcomes. Markers with the strongest association were included in multivariate stepwise regression. Final model of hospital readmission or death was derived using stepwise selection. MEASUREMENTS: Nutritional, inflammatory, hormonal and muscle biomarkers. RESULTS: Mean age was 76 years, 51% were men. In univariate models, 10 biomarkers were significantly associated with 90-day outcomes and 4 biomarkers with 30-day outcomes. In multivariate stepwise selection, glutamate, hydroxyproline, tau-methylhistidine levels, and sex were associated with death and readmission within 90-days. In stepwise selection, age-adjusted model that included sex and these 3 amino-acids demonstrated moderate discriminating ability over 90-days (C-statistic 0.68 (95%CI 0.61, 0.75); age-adjusted model that included sex, hydroxyproline and Charlson Comorbidity Index was predictive of 30-day outcomes (C-statistic 0.76 (95%CI 0.68, 0.85). CONCLUSIONS: Baseline glutamate, hydroxyproline, and tau-methylhistidine levels, along with sex and age, predict risk of 90-day mortality and nonelective readmission in malnourished hospitalized older patients. This biomarker set should be further validated in prospective studies and could be useful in prognostication of malnourished hospitalized patients and guiding in-hospital care.

Economic Impact of Hospitalizations in US Adults with Sarcopenia.

BACKGROUND: Sarcopenia is characterized by progressive loss of muscle mass with corresponding decline in strength and/or physical function. The economic burden of sarcopenia-associated disability is considerable in the US. OBJECTIVE: To estimate the cost of hospitalizations in US adults with sarcopenia categorized by age, sex, and race/ethnicity. DESIGN, SETTING AND PARTICIPANTS: A retrospective, prevalence based, economic burden study, consisting of 4011 adults aged ≥40 years with and without sarcopenia. METHODS: Data on prevalence of low lean mass, functional limitations, and hospitalizations were obtained from the National Health and Nutrition Examination Survey (1999-2004); cost of hospitalizations was obtained from the Healthcare Cost and Utilization Project - National Inpatient Sample (2014), and population estimates were obtained from the US Census (2014). Probability and cost of hospitalizations were estimated by multiple logistic regression and negative binomial regression models, respectively. RESULTS: The total estimated cost of hospitalizations in individuals with sarcopenia was USD $40.4 billion with an average per person cost of USD $260. Within this category, average per person cost was highest for Hispanic women (USD $548) and lowest for Non-Hispanic Black women (USD $25); average per person cost was higher for older adults (≥65 years) (USD $375) than younger adults (40-64 years) (USD $204) with sarcopenia. The total cost of hospitalizations in individuals with sarcopenia (≥65 years) was USD $19.12 billion. Individuals with sarcopenia had greater odds of hospitalization (OR, 1.95; p<.001) compared to those without and had an annual marginal increase in cost of USD $2315.7 per person compared to individuals without sarcopenia. CONCLUSION: Sarcopenia places considerable economic burden on the US healthcare system. The ethnic disparity and economic burden associated with sarcopenia warrant further investigation.

Role of Oral Nutritional Supplements Enriched with ß-Hydroxy-ß-Methylbutyrate in Maintaining Muscle Function and Improving Clinical Outcomes in Various Clinical Settings.

Aging and disease-related malnutrition are well associated with loss of muscle mass and function. Muscle mass loss may lead to increased health complications and associated increase in health care costs, especially in hospitalized individuals. High protein oral nutritional supplements enriched with ß-hydroxy-ß-methylbutyrate (HP-ONS+HMB) have been suggested to provide benefits such as improving body composition, maintaining muscle mass and function and even decreasing mortality rates. The present review aimed to examine current evidence on the effect of HP-ONS+HMB on muscle-related clinical outcomes both in community and peri-hospitalization patients. Overall, current evidence suggests that therapeutic nutrition such as HP-ONS+HMB seems to be a promising tool to mitigate the decline in muscle mass and preserve muscle function, especially during hospital rehabilitation and recovery.

Fetal Hemodynamic Parameters in Low Risk Pregnancies: Doppler Velocimetry of Uterine, Umbilical, and Middle Cerebral Artery.

Objective. To elaborate curves of longitudinal reference intervals of pulsatility index (PI) and systolic velocity (SV) for uterine (UtA), umbilical (UA), and middle cerebral arteries (MCA), in low risk pregnancies. Methods. Doppler velocimetric measurements of PI and SV from 63 low risk pregnant women between 16 and 41 weeks of gestational age. Means (±SD) for intervals of gestational age and percentiles 5, 50, and 95 were calculated for each parameter. The Intraclass Correlation Coefficients (ICC) were also estimated for assessing intra- and intervariability of measurements. Results. Mean PI of UtA showed decreasing values during pregnancy, but no regular pattern was identified for mean SV. For UA, PI decreased and SV increased along gestation. MCA presented PI increasing values until 32-35 weeks. SV showed higher levels with increasing gestation. High ICC values indicated good reproducibility. Conclusions. Reference intervals for the assessment of SV and PI of UtA, UA, and MCA were established. These reference intervals showed how a normal pregnancy is expected to progress regarding these Doppler velocimetric parameters and are useful to follow high risk pregnancies. The comparison between results using different curves may provide insights about the best patterns to be used.

Prebiótico, probiótico e simbiótico para larvas de Trichogaster leeri (Bleeker, 1852, Perciformes, Osphronemidae) / Prebiotic, probiotic and symbiotic for Trichogaster leeri larvae (Bleeker, 1852, Perciformes, Osphronemidae)

Avaliou-se a suplementação de prebiótico (mananoligossacarídeo - 2g/kg), probiótico (Bacillus subtilis, Cohn, 1872, Bacillales, Bacillaceae - 2g/kg) e simbiótico (mananoligossacarídeo - 2g/kg + B. subtilis - 2g/kg), em rações para larvas de Trichogaster leeri (Bleeker, 1852, Perciformes, Osphronemidae), durante a transição alimentar, sobre o crescimento, a sobrevivência, a morfometria intestinal e a resistência ao estresse por exposição aérea. Para isso, 420 larvas (0,45±0,05mg) foram distribuídas em 20 aquários (3,5L), em delineamento inteiramente ao acaso, com cinco tratamentos e quatro repetições, durante 28 dias, a saber: 12 dias de alimento vivo (AV) + oito dias de coalimentação (AV + ração controle) + oito dias de ração controle; 12 dias de AV + oito dias de coalimentação (AV + ração prebiótico) + oito dias de ração prebiótico; 12 dias de AV + oito dias de coalimentação (AV + ração probiótico) + oito dias de ração probiótico; 12 dias de AV + oito dias de coalimentação (AV + ração simbiótico) + oito dias de ração simbiótico; 28 dias de AV. Larvas que receberam apenas AV apresentaram resultados de desempenho zootécnico significativamente superiores às larvas dos demais tratamentos, exceto para taxa de crescimento específico em comprimento e sobrevivência, que foram semelhantes aos resultados obtidos por larvas que receberam rações suplementadas com simbiótico. Larvas que receberam a ração controle apresentaram resultados significativamente inferiores para altura das vilosidades intestinais e taxa de resistência ao estresse comparando-se aos demais tratamentos. Os resultados deste estudo indicam que a suplementação com prebiótico, probiótico e simbiótico exerce efeito positivo sobre a sobrevivência, a morfometria intestinal e a resistência ao estresse em larvas de T. leeri, no entanto somente a suplementação com simbiótico resulta em melhora no crescimento.(AU)

The prebiotic (mannan oligosaccharide - 2g/kg), probiotic (Bacillus subtilis Cohn, 1872, Bacillales, Bacillaceae - 2g/kg) and symbiotic (mannan oligosaccharide - 2g/kg + Bacillus subtilis - 2g/kg) supplementation in diets during food transition in Trichogaster leeri (Bleeker, 1852, Perciformes, Osphronemidae) larvae on growth, survival, intestinal morphology and stress resistance to air exposure was evaluated. For this, 420 larvae (0.45±0.05mg) were distributed in 20 aquaria (3.5L) in a completely randomized design with five treatments and four replications for 28 days, namely: 12 days of live food (LF) + eight days of co-feeding (LF + control diet) + eight days of control diet; 12 days of LF + eight days of co-feeding (LF + prebiotic feed) + eight days of prebiotic feed; 12 days of LF + eight days of co-feeding (LF + probiotic feed) + eight days of probiotic feed; 12 days of LF + eight days of co-feeding (LF + symbiotic feed) + eight days symbiotic feed; 28 days of LF. Larvae fed only LF showed growth performance significantly higher than the larvae of other treatments, except for specific growth rate in length and survival that were similar to the results obtained by larvae fed diets symbiotically supplemented. Larvae fed the control diet showed significantly lower results for height of intestinal villi and stress resistance rate comparing to other treatments. The results of this study indicate that prebiotic, probiotic and symbiotic supplementation has a positive effect on survival, intestinal morphology and resistance to stress in larvae of T. leeri, however, only symbiotic supplementation results in improved growth.(AU)

Hypoglycemic Effect of the Methanol flower Extract of Piper Claussenianum and the Major Constituent 2',6'-dihydroxy-4'-methoxychalcone in Streptozotocin Diabetic Rats.

Piper claussenianum inflorescences crude methanol extract was tested for hypoglycemic effect in streptozotocin-induced diabetic rats. The blood glucose levels of rats treated with methanol extract were reduced from 318.4±28.1 mg/dl before treatment to 174.2±38.3 mg/dl after 12 days of treatment (P<0.05). Phytochemical studies were carried out on inflorescences methanol crude extract in order to investigate the possible metabolites responsible for the pharmacological properties of the extract. After chromatographic procedures, three flavonoids were isolated and characterized. The major compound 2',6'-dihydroxy-4'-methoxychalcone was also tested. Rats that received the chalcone content also displayed a reduction in blood glucose levels from 277.4±7.7 mg/dl before treatment to 158.8±9.2 mg/dl after 12 days of treatment (P<0.05). The results suggest this chalcone is one of the metabolite responsible for the blood glucose levels reduction in rats with streptozotocin-induced diabetes. The inflorescence crude extract of P. claussenianum was found to be composed mainly by flavonoids and may be a potential natural source of compounds with hypoglycemic properties.

The Green Tea Polyphenol Epigallocatechin-3-Gallate (EGCg) Attenuates Skeletal Muscle Atrophy in a Rat Model of Sarcopenia.

OBJECTIVE: Sarcopenia-the loss of muscle mass and functionality occurring with age-is a pervasive problem with few effective treatments beyond exercise. We examined the ability of the green tea catechin, epigallocatechin-3-gallate (EGCg), to impact muscle mass and the molecular pathway involved in muscle atrophy in a rat model of sarcopenia. METHODS: 20-month-old Sprague-Dawley rats were treated for 8 weeks with control diet or control plus 200mg/kg body weight of EGCg diet. RESULTS: EGCg-supplemented animals had significantly greater gastrocnemius muscle mass than the aged controls, and showed a trend for increased muscle fiber cross-sectional areas (CSA) (p=0.06). These changes were associated with significantly lower protein expressions of the intramuscular 19S and 20S proteasome subunits and the MuRF1 and MAFbx ubiquitin ligases in the EGCg-treated animals. Proteasome activity as determined by 'Chymotrypsin-like' enzyme activity was also significantly reduced by EGCg. Muscle mRNA expression of IL-15 and IGF-1 were significantly increased in the EGCg group vs. the aged controls. In comparison to younger adult animals (6 month), the protein expression of 19S, 20S, MuRF1, MAFbx, and myostatin were increased between approximately 4- and 12-fold in the aged controls, but only up to ~2-fold in the aged EGCg animals. CONCLUSIONS: EGCg supplementation was able to preserve muscle in sarcopenic rats, partly through attenuating protein degradation via the ubiquitin-proteasome pathway, together with increased expression of anabolic factors.

Efeito da densidade de estocagem no desenvolvimento inicial do acará-bandeira (Pterophyllum scalare) / The effect of storage density in the early development of angelfish (Pterophyllum scalare)

Avaliou-se a influência da densidade de estocagem no desenvolvimento inicial do acará-bandeira (Pterophyllum scalare). O desempenho produtivo foi avaliado pelo ganho de peso (GP), ganho de comprimento total (GCT), ganho de comprimento padrão (GCP), ganho de altura (GA), taxa de crescimento específico (TCE), taxa de desenvolvimento específico (TDE) e sobrevivência (S). Para realização do experimento, foram utilizadas 300 pós-larvas de peso médio inicial de 0,0012g, comprimento total médio de 4,11±0,93mm, altura média inicial de 4,84±0,87mm e comprimento padrão médio de 1,54±0,25mm. Essas foram distribuídas em delineamento inteiramente ao acaso, em cinco tratamentos com quatro repetições. Os tratamentos (T) foram constituídos por cinco diferentes densidades de estocagem, em que T1: 5 pós-larvas L-1; T2: 10 pós-larvas L-1; T3: 15 pós-larvas L-1; T4: 20 pós-larvas L-1; T5: 25 pós-larvas L-1. A densidade de 5 pós-larvas L-1 foi a que proporcionou o maior valor para crescimento. Contudo, essa densidade subestimou a utilização do espaço se comparada com a produtividade final da densidade de 15 pós-larvas L-1.

The influence of stocking density in the initial development of angelfish (Pterophyllum scalare) was evaluated. The productive performance was evaluated by weight gain (WG) gain length (GCT), standard length gain (GCP), height gain (GH), specific growth rate (TCE), specific development rate (TDE) and survival (S). For the experiment we used a total of 300 post-larvae angelfish with initial body weight of 0.0012 g, total length of 4.11±0.93mm, initial height of 4.84±0.87mm, and average standard length of 1.54±0.25mm. These were distributed in a completely randomized design in five treatments with four replications. The treatments consisted of five different stocking densities where T1: 5 post-larvae L-1, T2: 10 post-larvae L-1, T3: 15 post-larvae L-1, T4: 20 post-larvae L-1, T5: 25 post-larvae L-1. The physical and chemical water parameters were monitored daily. The density of post-larvae 5 L-1 was the one that gave the highest growth values. However, despite the post-larvae 5 L-1 density having provided larger animals, the density underestimates the use of space compared to the final productivity of the 15 post-larvae L-1density.

Recurrent neuromyelitis optica in Brazilian patients: clinical, immunological, and neuroimaging characteristics.

Neuromyelitis optica has not been thoroughly studied in Brazilian patients following the discovery of NMO-IgG and its specific antigen aquaporin-4. In this study we aimed to describe the clinical NMO-IgG immunological status and neuroimaging characteristics of recurrent neuromyelitis optica in a series Brazilian patients. We undertook a retrospective study of 28 patients with recurrent neuromyelitis optica, according to 1999 Wingerchuk's diagnostic criteria. Data on NMO-IgG status, clinical features, and MRI findings were analyzed. Three men and 25 women were evaluated. Median age at onset of disease was 26 years (range 7-55); median time of follow-up was 7 years (range 2-14). The mean time elapsed between the first and the second attack was 17 months (median 8.5; range 2-88). NMO-IgG was detected in 18 patients (64.3%). Four patients died due to respiratory failure. Most patients presented with cervical (36%) and cervical-thoracic myelitis (46.4%). Holocord lesion was the most common pattern of involvement (50%) on the axial plane. We did not find a statistical association between myelitis extension and NMO-IgG result. Our series of Brazilian patients showed a younger age of onset than previously reported. In our series, in contrast to previous reports, there was no correlation between the extension of myelitis and NMO-IgG positivity.

Colposcopy 101: a didactic curriculum to complement the clinical experience.

The family medicine faculty who perform colposcopy at the University of Missouri-Columbia have developed an innovative didactic curriculum that is used as an adjunct to the clinical experience in teaching family practice residents about colposcopy. The curriculum is taught weekly during a colposcopy conference that is held in the family practice center and includes core topic lectures, pathology-correlate lectures, and a journal club. The core lecture series has 26 topics that range from basic to advanced colposcopy. Pathology-correlate lectures combine pathologic evaluation with the clinical colposcopic examination. The journal club systematically reviews and evaluates the colposcopy literature.

Archaeal histone selection of nucleosome positioning sequences and the procaryotic origin of histone-dependent genome evolution.

Archaeal histones and the eucaryal (eucaryotic) nucleosome core histones have almost identical histone folds. Here, we show that DNA molecules selectively incorporated by rHMfB (recombinant archaeal histone B from Methanothermus fervidus) into archaeal nucleosomes from a mixture of approximately 10(14) random sequence molecules contain sequence motifs shown previously to direct eucaryal nucleosome positioning. The dinucleotides GC, AA (=TT) and TA are repeated at approximately 10 bp intervals, with the GC harmonic displaced approximately 5 bp from the AA and TA harmonics [(GCN(3)AA or TA)(n)]. AT and CG were not strongly selected, indicating that TA not equalAT and GC not equalCG in terms of facilitating archaeal nucleosome assembly. The selected molecules have affinities for rHMfB ranging from approximately 9 to 18-fold higher than the level of affinity of the starting population, and direct the positioned assembly of archaeal nucleosomes. Fourier-transform analyses have revealed that AA dinucleotides are much enriched at approximately 10. 1 bp intervals, the helical repeat of DNA wrapped around a nucleosome, in the genomes of Eucarya and the histone-containing Euryarchaeota, but not in the genomes of Bacteria and Crenarchaeota, procaryotes that do not have histones. Facilitating histone packaging of genomic DNA has apparently therefore imposed constraints on genome sequence evolution, and since archaeal histones have no structure in addition to the histone fold, these constraints must result predominantly from histone fold-DNA contacts. Based on the three-domain universal phylogeny, histones and histone-dependent genome sequence evolution most likely evolved after the bacterial-archaeal divergence but before the archaeal-eucaryal divergence, and were subsequently lost in the Crenarchaeota. However, with lateral gene transfer, the first histone fold could alternatively have evolved after the archaeal-eucaryal divergence, early in either the euryarchaeal or eucaryal lineages.

Comparison of bioabsorbable and non-resorbable membranes in the treatment of dehiscence-type defects. A histomorphometric study in dogs.

BACKGROUND: The goal of this investigation was to compare, histologically and histometrically, the healing process of dehiscence-type defects treated by guided tissue regeneration (GTR) with bioabsorbable polylactic acid (PLA) membranes and non-resorbable expanded polytetrafluoroethylene (ePTF) membranes. METHODS: Six mongrel dogs were used. Buccal osseous dehiscences were surgically created on the distal roots of the mandibular third and fourth premolars. The defects were exposed to plaque accumulation for 3 months. After this period, the defects were randomly assigned to one of the treatments: GTR with bioabsorbable membrane (PLA), GTR with non-resorbable membrane (ePTFE), open flap debridement (OFD), and non-treated control (NTC). After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included: gingival recession, epithelial length, connective tissue adaptation, new cementum, and new bone area. RESULTS: A superior length of new cementum was observed in the sites treated by GTR, regardless of the type of barrier used, in comparison with OFD (P <0.05). No statistically significant differences were found between PLA and ePTFE in any of the parameters with the exception of bone area. PLA presented a greater bone area when compared to ePTFE, OFD, and NTC (P <0.05). CONCLUSIONS: Within the limits of this study, it can be concluded that both barriers are equally effective for new cementum formation. The bioabsorbable membrane may provide a greater bone area than the non-resorbable membrane.

MJ1647, an open reading frame in the genome of the hyperthermophile Methanococcus jannaschii, encodes a very thermostable archaeal histone with a C-terminal extension.

All archaeal histones studied to date have similar lengths, 66 to 69 amino acid residues that form three alpha-helices separated by two beta-strand loop regions which together constitute a histone fold. In contrast, the eukaryal nucleosome core histones are larger, 102 to 135 residues in length, with N-terminal and C-terminal extensions flanking the histone fold that participate in gene regulation and higher-order chromatin assembly. In the Methanococcus jannaschii genome, MJ1647 was annotated as an open reading frame predicted to encode an archaeal histone with an approximately 27-amino-acid C-terminal extension, and we here document the DNA binding and assembly properties and thermodynamic stability parameters of the recombinant product of MJ1647 synthesized in Escherichia coli with (rMJ1647) and without (rMJ1647delta) the C-terminal extension. The presence of the C-terminal extension did not prevent homodimer formation or inhibit DNA binding, but the complexes formed by rMJ1647, presumably archaeal nucleosomes containing a (rMJ1647)4 tetramer, were apparently less stable than those formed by (rMJ1647delta)4. The presence of the C-terminal extension increased the thermostability of rMJ1647 when compared with rMJ1647delta in 0.2 M KCl at pH 4 but not in the absence of KCl at pH 1. Based on thermal unfolding transitions, rMJ1647 and rHAfB generated by expression of AF0337 cloned from the genome of the related hyperthermophile Archaeoglobus fulgidus in E. coli were found to have higher thermodynamic stabilities than all previously studied archaeal histones.

Guided tissue regeneration with a bioabsorbable polylactic acid membrane in gingival recessions. A histometric study in dogs.

BACKGROUND: The goal of this investigation was to histologically and histometrically evaluate the healing process of gingival recessions treated by guided tissue regeneration with bioabsorbable polylactic acid membranes (GTR group) and to compare it to that obtained with coronally positioned flaps (CPF group). METHODS: Gingival recessions were surgically created on the buccal aspect of the upper cuspids of 5 mongrel dogs. The defects (5x7 mm) were exposed to plaque accumulation for 3 months. The contralateral defects were then randomly assigned to each group. After 3 months of healing, the dogs were sacrificed and the blocks were processed. The histometric parameters evaluated included length of sulcular and junctional epithelium, connective tissue adaptation, new cementum, new bone, and defect coverage. RESULTS: The extension of the epithelium was 1.9 +/- 0.8 mm for the GTR-group and 3.0 +/- 0.9 mm for the CPF-group (P = 0.16). The connective tissue adaptation was 0.1 +/- 0.1 and 0.8 +/- 0.5 mm in the GTR group and CPF group, respectively (P = 0.051). The new cementum was 3.8 +/- 1.5 mm and 2.4 +/- 0.3 mm in the GTR group and CPF group, respectively (P= 0.16). Bone formation was 1.1 +/- 0.5 mm in the GTR group and 1.4 +/- 0.2 mm in the CPF group (P = 0.53). Histologically, the defect coverage observed was similar, 90.5% and 91.9% for the GTR group and the CPF group, respectively. No statistical differences in any of the parameters could be detected. CONCLUSIONS: Within the limits of this study, it can be concluded that both procedures resulted in a favorable healing response with no significant difference between the treatments.