Synthesis and antimicrobial evaluation of piperic acid amides and their lower homologues

Seven piperic acid amides along with their lower homologs (12) were synthesized using HATU-DIPEA coupling reagent. All the synthesized derivatives were evaluated for their antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and vancomycin-resistant P. aeruginosa. They were found to be more active on P. aeruginosa than on S. aureus. However, they did not exhibit potent activity on Vancomycin resistant P. aeruginosa. Among the tested compounds, methylenedioxycinnamic acid amide of anthranilic acid (MDCA-AA, 2a) was found to be most active against S. aureus with MIC of 3.125 μg/ml. The PAS and INH amides of piperic acid were screened against Mycobacterium tuberculosis H37R_a strain. They were found to be most active among all the tested compounds but were found to be less active than the standard drug, isoniazid.     

Combination of two desensitizing protocols to control dentin hypersensitivity in non-carious lesions: a randomized,double-blind clinical trial

Clinical Oral Investigations - This study evaluated the effect of photobiomodulation (PBM) combined with 8% strontium acetate (SA8%) in the treatment of dentin hypersensitivity (DH) in non-carious...     

Effect of antibodies on the expression of Plasmodium falciparum circumsporozoite protein gene

Antibodies are known to play an important role in the control of malaria infection. However, they can modulate parasite development enhancing infection. The effect of anti-Plasmodium antibodies on the expression of circumsporozoite protein gene (csp) was investigated. Plasmodium falciparum 3D7 in vitro cultures were submitted to: i) anti- circumsporozoite protein monoclonal antibody (anti-CSP-mAb) [1microg/ml, 0.1microg/ml, 0.01microg/ml and 0.001microg/ml] and ii) purified IgG Fab fragment from a pool of malaria patients [1mg/ml and 1microg/ml]; and compared to control cultures. After 24h the number of ring infected erythrocytes was determined in order to calculate invasion efficacy. At 48h culture supernatant was collected, and the amount of circumsporozoite protein determined by ELISA, parasitaemia was calculated and cells were processed for RNA preparation. Expression of csp gene was quantified using Real time RT-PCR. There was an increase in parasite growth when treated with lower anti-CSP-mAb concentration, which was associated with lower csp expression, while 1mug/ml anti-CSP-mAb treatment presented a growth inhibitory effect accompanied by high csp expression.     

Metabolic and hormonal assessment of patients on maintenance hemodialysis for 10 years or more and their importance in long-term survival

We studied metabolic and hormonal patterns in 11 patients on hemodialysis for over 10 years (group A) to determine whether some metabolic abnormalities worsen with long-term dialysis or whether a particular endocrine-metabolic pattern discriminates long-term hemodialysis survivors. Data were compared to those of 14 subjects of similar age and sex on dialysis for 1-3 years (group B) and to those measured in the same patients during the 1st year of dialytic treatment. As to glucose metabolism, group A showed elevation of fasting plasma glucose and a decrease of glucose constant decay (K) and insulin production (IIG) values as compared to the 1st year of dialysis. No difference was found between group A now and group B. However in the 1st year of dialysis group A showed significantly higher K values than group B. As regards lipid metabolism, group A presented higher alpha-lipoprotein values and high-density lipoprotein-cholesterol/cholesterol, high-density lipoprotein-cholesterol/apoprotein A, and apoprotein A/apoprotein B ratios, while low-density lipoprotein-cholesterol and apoprotein B values and beta/alpha-lipoprotein ratio were lower. These data demonstrate less vascular risk in group A. We explain these results as depending on natural selection. Multivariate analysis of survival confirmed that survival in hemodialysis patients is influenced negatively by glucose and lipid metabolism abnormalities. As to Ca-P metabolism, group A showed higher carboxy-terminal parathyroid hormone and alkaline phosphatase values than group B. However, these data may be superimposed to those determined in the same patients in 1981, when we began the regular use of 1 alpha,25-(OH)2-vitamin D3.(ABSTRACT TRUNCATED AT 250 WORDS)     

Tobacco and health in the view of univerity students

Smoking is a serious public health problem. This study aims at understanding how social representation about smoke/tobacco and health are shared by young university students through the impact of figures contained in cigarettes package in heath. This exploratory study was carried with 63 nursing students in Lisboa, Portugal. Data were collected by the technique of free association of words that were submitted to the software Tri-Deux Mots. Students associate "tobacco" like pleasure but also as cancer, disrespect, bad smell, something mean; the health, happiness, joy and self and sickness. is represented by hospital but also as something good positive and energetic. "Tobacco/smoking" for the subjects concerned disease as the cancer in addition to causing bad smell and be unpleasant configuring itself as a bad and associated with father.     

Meiotic behaviour of holocentric chromosomes: orientation and segregation of autosomes in Triatoma infestans (Heteroptera)

The meiotic behaviour of the holocentric chromosomes of the heteropteran species Triatoma infestans has been analysed by means of orcein staining and C-banding on squashed spermatocytes. We have focused our analysis on chromosome 3, which shows a large distal heterochromatic band at one of the ends of both homologues. At metaphase I,and independently of the chiasma position, two alternative orientations have been observed: either the hetero-chromatic or the euchromatic ends of both homologues are directed to opposite poles. At anaphase I, the kinetic activity is restricted to the same chromosome end (euchromatic or heterochromatic) of each homologue. The frequencies of these two alternatives are not random and differ significantly among the five individuals analysed. However, the euchromatic ends present kinetic activity at a higher frequency than the heterochromatic ends. At metaphase II, half-bivalents also show the kinetic activity restricted to either of the chromosome ends (euchromatic orheterochromatic). The frequencies of each alternative are inverted in anaphase II compared with those scored in anaphase I. Accordingly, those ends that present kinetic activity at anaphase I segregate reductionally during the first meiotic division and equationally during the second meiotic division. These results provide sound evidence on the meiotic behaviour of holocentric chromosomes, as regards the absence of chiasma terminalization and the modes of orientation and segregation. This revised version was published online in August 2006 with corrections to the Cover Date.     

Effect of photobiomodulation with low-level laser therapy combined with potassium nitrate on controlling post-bleaching tooth sensitivity: clinical,randomized, controlled,double-blind,and split-mouth study

Objectives

To evaluate the effect of photobiomodulation with low-level laser therapy (PBM-LLLT) combined with 5% potassium nitrate (KNO₃) on controlling tooth sensitivity (TS) after in-office tooth bleaching.

Materials and methods

Fifty volunteers were selected based on the inclusion and exclusion criteria and were randomly allocated into four groups: G1 (control): placebo gel application, 35% hydrogen peroxide bleaching (HP35) and mock PBM-LLLT without light emission; G2: placebo gel application, bleaching with HP35 and PBM-LLLT; G3: application of KNO₃, bleaching with HP35 and mock PBM-LLLT; and G4: application of KNO₃, bleaching with HP35 and PBM-LLLT. A pain assessment questionnaire was used to evaluate TS during the 21 days of treatment. The Friedman test was used for intragroup analysis, and the Wilcoxon and Mann-Whitney tests were used for intergroup comparisons.

Results

The intragroup evaluation showed significant differences among the evaluation times in all groups (p ≤ 0.05). The highest pain sensitivity levels were recorded on the 1st, 8th, and 15th days. In G1, TS manifested for up to 3 days after each bleaching session, while G2, G3, and G4 presented TS only on the days of the bleaching sessions. Intergroup analysis showed that TS manifestation differed significantly between G1 and the other groups (p ≤ 0.05) but did not differ significantly among G2, G3, and G4 (p ≥ 0.05).

Conclusion

PBM-LLLT and KNO₃ are effective at reducing pain sensitivity after tooth bleaching, but no synergistic effect between these treatments was observed for the different evaluation periods.

Clinical relevance

The effect of PBM-LLLT combined with KNO₃ on post-bleaching tooth sensitivity is similar to their individual use alone.

     

Assessment and Classification of Mechanical Strength Components of Human Femur Trabecular Bone Using Texture Analysis and Neural Network

In this work the mechanical strength components of human femur trabecular bone are analyzed and classified using planar radiographic images and neural network. The mechanical strength regions such as Primary Compressive, Primary Tensile, Secondary Tensile and Ward Triangle in femur trabecular bone images (N = 100) are delineated by semi-automatic image processing procedure. First and higher order texture parameters and parameters such as apparent mineralization and total area associated with the strength regions are derived for normal and abnormal images. The statistically derived significant parameters corresponding to the primary strength regions are fed to the neural network for training and validation. The classifications are carried out using feed forward network that is trained with standard back propagation algorithm. Results demonstrate that the apparent mineralization of normal samples is always high as (71%) compared to abnormal samples (64%). Entropy shows a high value (7.3) for normal samples and variation between the mean intensity and apparent mineralization for the primary strength zone is statistically significant (p < 0.0005). The classified outputs are validated by sensitivity and specificity measurements and are found to be 66.66% and 80% respectively. Further it appears that it is possible to differentiate normal and abnormal samples from the conventional radiographic images. As trabecular architecture in the human femur is an important factor contributing to bone strength, the procedure adopted here could be a useful supplement to the clinical observations for bone loss and fracture risk.     

Identification, N-terminal region sequencing and similarity analysis of differentially expressed proteins in Paracoccidioides brasiliensis.

Paracoccidioides brasiliensis is the causal agent of paracoccidioidomycosis, which is a systemic mycosis in Latin America. This human pathogen is a dimorphic fungus existing as mycelium (26 degrees C) and in infected tissues as a yeast form (36 degrees C). The in vitro differentiation process is reversible and dependent on temperature shift. In the present study, the total proteins from both forms of P. brasiliensis (isolate Pb01) were analysed by two-dimensional electrophoresis. Differentially expressed proteins were identified. Two of these proteins, PbM46 (mycelium) and PbY20 (yeast), were submitted to automated protein sequencing of their N-terminal regions. The 15 amino acid residue sequence of PbM46, AITKIFALKVYDSSG, is similar to enolases from several sources, and specially those from Saccharomyces cerevisiae (80%) and Candida albicans (67%), when compared to the NR database at NCBI using the BLASTP program. The 34 amino acid residue sequence of PbY20, APKIAIVFYSLYGHIQKLAEAQKKGIEAAGGTAD, could probably represent an allergen protein since it is very similar (90%) to the minor allergen protein of Alternaria alternata and 82% similar to the allergen protein of Cladosporium herbarum. This comparative analysis of proteins from mycelium and yeast forms has allowed the identification and characterization of differentially expressed proteins, probably related to differential gene expression in P. brasiliensis.