The use of laser-based diagnostics for the rapid identification of infectious agents in human blood.

AIMS: To investigate the use of a laser-based method of detection as a potential diagnostic test for the rapid identification of infectious agents in human blood. METHODS AND RESULTS: In this study, the successful differentiation of blood spiked with viruses, bacteria or protozoan parasites to clinically relevant levels is demonstrated using six blood types (O+, O-, AB+, A+, A-, B+) using blood from different individuals with blood samples prepared in two different laboratories. Experiments were performed using various compositions of filters, experimental set-ups and experimental parameters for spectral capture. CONCLUSIONS: The potential for developing a laser-based diagnostic instrument to detect the presence of parasites, bacteria and viruses in human blood capable of providing analysis results within minutes was demonstrated. SIGNIFICANCE AND IMPACT OF THE STUDY: There is an ongoing need for clinical diagnostics to adapt to newly emerging agents and to screen simultaneously for multiple infectious agents. A laser-based approach can achieve sensitive, multiplex detection with minimal sample preparation and provide rapid results (within minutes). These properties along with the flexibility to add new agent detection by simply adjusting the detection programming make it a promising tool for clinical diagnosis.

Dietary total antioxidant capacity and the risk of breast cancer: a case-control study.

There is growing evidence that dietary antioxidants may have favourable effects in reducing cancer risk. In a case-control study we investigated the association of dietary total antioxidant capacity (TAC) and risk of breast cancer. Sociodemographic data, medical history and anthropometric measurements were collected from 275 women (100 breast cancer cases & 175 controls). Participants' usual dietary intake was measured using a validated semi-quantitative food frequency questionnaire and their dietary TAC was estimated. An inverse, but non-significant, association was observed between dietary TAC and breast cancer risk. Multiple logistic regression models based on TAC of individual food groups showed that consumption of fruits and vegetables with higher TAC (µmolTE/100 g) was associated with a significantly decreased risk of breast cancer. Our study supports a protective effect of dietary antioxidants in relation to breast cancer risk. Food selection based on TAC of foods may be an effective strategy to modify the risk of cancer.

[Evaluation of the quality of proximal restorations with plastic materials: radiographic study]. / Evaluation de la qualité des restaurations proximales aux matériaux plastiques. Etude radiographique.

AIM: To assess the quality of proximal coronary restorations and bring out the factors influencing this quality. MATERIAL AND METHOD: A transversal study on 160 radiographs of proximal coronary restorations was conducted at the University Center of Dental Consultation and Treatment of Rabat. Restorations were evaluated according to the modified USPHS criteria. Four variables were studied: restoration material, treated tooth, cavity type and location of treatment in order to identify the influencing factors. RESULTS: Forty five per cent of the evaluated proximal coronary restorations required replacement. The main cause of failure was recurrent caries in 36% of cases, followed by the absence of the contact point (24.4%), unacceptable proximal coronary outline (13.8%), and finally dentin exposure (6.9%). Thus, it turned out that there is a difficulty to restore correctly posterior proximal cavities especially using amalgam and a high rate of recurrent caries at both the anterior and posterior teeth. CONCLUSION: Both a clinical and a radiographic evaluation after each proximal restoration would be recommended to reduce failure.

Microstructural evolution of bainitic steel severely deformed by equal channel angular pressing.

High Si bainitic steel has been received much of interest because of combined ultra high strength, good ductility along with high wear resistance. In this study a high Si bainitic steel (Fe-0.22C-2.0Si-3.0Mn) was used with a proper microstructure which could endure severe plastic deformation. In order to study the effect of severe plastic deformation on the microstructure and properties of bainitic steel, Equal Channel Angular Pressing was performed in two passes at room temperature. Optical, SEM and TEM microscopies were used to examine the microstructure of specimens before and after Equal Channel Angular Pressing processing. X-ray diffraction was used to measure retained austenite after austempering and Equal Channel Angular Pressing processing. It can be seen that retained austenite picks had removed after Equal Channel Angular Pressing which could attributed to the transformation of austenite to martensite during severe plastic deformation. Enhancement of hardness values by number of Equal Channel Angular Pressing confirms this idea.

Pegylated and amphiphilic Chitosan coated manganese ferrite nanoparticles for pH-sensitive delivery of methotrexate: Synthesis and characterization.

Magnetic nanoparticles (MNPs) are the major class of nanoparticles (NPs) with specific functional properties that make them good candidates for biomedical applications. Due to their response to the magnetic field, they can be used in targeted drug delivery systems. In current research, the MNPs were synthesized with the general formula of Fe1-xMnxFe2O4 by the co-precipitation technique. First, the effect of the Fe2+ ions in the system was investigated. Succinic anhydride was used as the first stabilizer to prepare surface for binding two types of polymer, including Polyethylene glycol (PEG) and palmitoylated Polyethylene glycol-grafted Chitosan (Cs-PEG-PA) were introduced as a polymeric shell. The composition, size, structure and magnetic properties of NPs were determined by the particle size analysis (PSA), X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer (VSM). Determining the well-defined properties of MNPs, methotrexate (MTX), as a common anticancer drug, was encapsulated into the coated MNPs. The drug encapsulation efficiency was as high as 92.8% with the magnetization value of 19.7emu/g. The in-vitro release pattern was studied, showing only 6% of the drug release in pH=7.4 (as a model of the physiological environment) and 25% in pH=5.4 (as a model of the tumor tissue environment) after 72h. Based on these results, we may be able to introduce this specific system as a novel pH sensitive MNP system for MTX targeting to tumor tissues in cancer chemotherapy.

Curved Beam Computed Tomography based Structural Rigidity Analysis of Bones with Simulated Lytic Defect: A Comparative Study with Finite Element Analysis.

In this paper, a CT based structural rigidity analysis (CTRA) method that incorporates bone intrinsic local curvature is introduced to assess the compressive failure load of human femur with simulated lytic defects. The proposed CTRA is based on a three dimensional curved beam theory to obtain critical stresses within the human femur model. To test the proposed method, ten human cadaveric femurs with and without simulated defects were mechanically tested under axial compression to failure. Quantitative computed tomography images were acquired from the samples, and CTRA and finite element analysis were performed to obtain the failure load as well as rigidities in both straight and curved cross sections. Experimental results were compared to the results obtained from FEA and CTRA. The failure loads predicated by curved beam CTRA and FEA are in agreement with experimental results. The results also show that the proposed method is an efficient and reliable method to find both the location and magnitude of failure load. Moreover, the results show that the proposed curved CTRA outperforms the regular straight beam CTRA, which ignores the bone intrinsic curvature and can be used as a useful tool in clinical practices.

Cooperative mechanisms involved in chronic antidiuretic response to bendroflumethiazide in rats with lithium-induced nephrogenic diabetes insipidus.

Previous studies of central diabetes insipidus suggested that thiazides acutely exerted a paradoxical antidiuresis by either indirectly activating volume-homeostatic reflexes to decrease distal fluid-delivery, or directly stimulating distal water-reabsorption. This study investigated whether the direct and indirect actions of bendroflumethiazide (BFTZ) simultaneously cooperated and also whether the renal nerves were involved in inducing long-term antidiuresis in nephrogenic diabetes insipidus (NDI). BFTZ or vehicle was gavaged into bilateral renal denervated and innervated rats with lithium-induced NDI for 10 days, constituting four groups. At one day before (D0) and one, five and ten days after starting administration of BFTZ or vehicle, rats were placed in metabolic cages to collect urine for 6 hours. BFTZ-treatment in both renal innervated and denervated rats caused equivalent reductions in urine-flow, creatinine clearance, lithium clearance and free-water clearance, but rises in urine-osmolality, fractional proximal reabsorption and fractional distal reabsorption at all days compared to D0, as well as to those of their relevant vehicle-received group. Therefore, the chronic antidiuretic response to BFTZ in conscious NDI rats was exerted through a concomitant cooperation of its direct distal effect of stimulating water-reabsorption and its indirect effect of reducing distal fluid-delivery by activating volume-homeostatic mechanisms, which appeared independent of the renal nerves.

Nano-magnetic particles used in biomedicine: core and coating materials.

Magnetic nanoparticles for medical applications have been developed by many researchers. Separation, immunoassay, drug delivery, magnetic resonance imaging and hyperthermia are enhanced by the use of suitable magnetic nanoparticles and coating materials in the form of ferrofluids. Due to their low biocompatibility and low dispersion in water solutions, nanoparticles that are used for biomedical applications require surface treatment. Various kinds of coating materials including organic materials (polymers), inorganic metals (gold, platinum) or metal oxides (aluminum oxide, cobalt oxide) have been attracted during the last few years. Based on the recent advances and the importance of nanomedicine in human life, this paper attempts to give a brief summary on the different ferrite nano-magnetic particles and coatings used in nanomedicine.

Determination and comparison of specifics of nucleus pulposus cells of human intervertebral disc in alginate and chitosan-gelatin scaffolds.

INTRODUCTION: Low back pain is a major economical and social problem nowadays. Intervertebral disc herniation and central degeneration of disc are two major reasons of low back pain that occur because of structural impairment of disc. The intervertebral disc contains three parts as follows : Annulus fibrosus, transitional region, and nucleus pulposus, which forms the central nucleus of the disc. The reduction of cell count and extracellular matrix, especially in nucleus pulposus, causes disc degeneration. Different scaffolds (natural and synthetic) have been used for tissue repairing and regeneration of the intervertebral disc in tissue engineering. Most scaffolds have biodegradable and biocompatible characteristics and also prepare a fine condition for proliferation and migration of cells. In this study, proliferation of NP cells of human intervertebral disc compromised in Chitosan-gelatin scaffold with alginate scaffold was studied. MATERIALS AND METHODS: NP cells derived from nucleus pulposus by collagenase enzymatic hydrolysis. They were derived from patients who undergoing open surgery for discectomy in the Isfahan Alzahra hospital. Chitosan was blended with gelatin and glutaraldehyde was used for cross linking the two polymers. Then, alginate scaffold was prepared. Cellular suspension with 1 × 10(5) transferred to each scaffold and cultured for 21 days. Cell viability and proliferation investigated by trypan blue and (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Scanning electron microscope (SEM) was used to assert the porosity and to survey structure of scaffold. RESULTS: MTT assay dem1onstrated that cell viability of third day had significant difference in contrast by first day in both scaffolds. Accordingly, there was a significant decreased in cellular viability from day 3 to 21. Results of the cell count showed a punctual elevation cell numbers for alginate scaffold but there was no similar result for chitosan-gelatin scaffold. CONCLUSION: Alginate scaffold prepared a better condition for proliferation of NP cells in comparison with chitosan-gelatin scaffold. Results of this study suggest that alginate scaffold could be useful in in vivo studies and treatment.

Fermentation, fractionation and purification of streptokinase by chemical reduction method.

BACKGROUND AND OBJECTIVES: Streptokinase is used clinically as an intravenous thrombolytic agent for the treatment of acute myocardial infarction and is commonly prepared from cultures of Streptococcus equisimilis strain H46A. The objective of the present study was the production of streptokinase from strain H46A and purification by chemical reduction method. MATERIALS AND METHODS: The rate of streptokinase production evaluated under the effect of changes on some fermentation factors. Moreover, due to the specific structure of streptokinase, a chemical reduction method employed for the purification of streptokinase from the fermentation broth. The H46A strain of group C streptococcus, was grown in a fermentor. The proper pH adjusted with NaOH under glucose feeding in an optimum temperature. The supernatant of the fermentation product was sterilized by filtration and concentrated by ultrafiltration. The pH of the concentrate was adjusted, cooled, and precipitated by methanol. Protein solution was reduced with dithiothreitol (DTT). Impurities settled down by aldrithiol-2 and the biological activity of supernatant containing streptokinase was determined. RESULTS: In the fed -batch culture, the rate of streptokinase production increased over two times as compared with the batch culture and the impurities were effectively separated from streptokinase by reduction method. CONCLUSION: Improvements in SK production are due to a decrease in lag phase period and increase in the growth rate of logarithmic phase. The methods of purification often result in unacceptable losses of streptokinase, but the chemical reduction method give high yield of streptokinase and is easy to perform it.

Dietary total antioxidant capacity and the risk of breast cancer:a case-control study

There is growing evidence that dietary antioxidants may have favourable effects in reducing cancer risk. In a case-control study we investigated the association of dietary total antioxidant capacity [TAC] and risk of breast cancer. Sociodemographic data, medical history and anthropometric measurements were collected from 275 women [100 breast cancer cases and 175 controls]. Participants' usual dietary intake was measured using a validated semi-quantitative food frequency questionnaire and their dietary TAC was estimated. An inverse, but non-significant, association was observed between dietary TAC and breast cancer risk. Multiple logistic regression models based on TAC of individual food groups showed that consumption of fruits and vegetables with higher TAC [micro molTE/100 g] was associated with a significantly decreased risk of breast cancer. Our study supports a protective effect of dietary antioxidants in relation to breast cancer risk. Food selection based on TAC of foods may be an effective strategy to modify the risk of cancer

Des données de plus en plus nombreuses indiquent que les antioxydants alimentaires ont des effets favorables sur la réduction du risque de cancer. Dans une étude cas-témoins,nous avons étudié l'association entre la capacité antioxydante totale de l'alimentaire et le risque de cancer du sein. Les données sociodémographiques, les antécédents médicaux et les mesures anthropométriques ont été recueillis auprès de 275 femmes [100 cas de cancer du sein et 175 cas témoins]. L'apport alimentaire habituel des participantes a été mesuré à l'aide d'un questionnaire semi-quantitatif validé sur la fréquence de consommation de l'alimentaire, puis la capacité antioxydante totale de l'alimentaire a été estimée. Une association inverse, mais non significative,a été observée entre la capacité antioxydante totale de l'alimentaire et le risque de cancer du sein. Des modèles de régression logistique multiple reposant sur la capacité antioxydante totale des groupes d'aliments individuels ont démontré que la consommation de fruits et de légumes ayant une capacité antioxydante totale plus élevée [micro molTE/100 g] était associée à un risque significativement moindre de cancer du sein.Notre étude confirme l'effet protecteur des antioxydants alimentaires contre le risque de cancer du sein. La sélection des aliments à partir de leur capacité antioxydante totale peut être une stratégie efficace pour modifier le risque de cancer

Helicobacter pylori bacterial ghost containing recombinant Omp18 as a putative vaccine.

Helicobacter pylori bacterial ghosts, HPBG, were generated by PhiX174 mechanism and loaded with recombinant Omp18, which were then applied in therapeutic immunization of Hp-infected C57BL/6 mice. Recombinant Omp18 loaded HPBG plus cholera toxin stimulated serum anti-Hp and Omp18-specific antibodies which resulted in significant reduction of gastric Hp colonization (P<0.05).

Persistent infections with Sendai virus and Newcastle disease viruses.

Persistent infections (Pi) were established in two host-cell systems [Madin-Darby bovine kidney (MDBK) and Madin-Darby canine kidney (MDCK)] with Sendai virus and three strains of NDV, to test the influence of different viruses and host-cell systems. Virus was recovered from the persistently infected cells. An RNA- ts mutant was recovered from a Pi of MDBK cells, but no Pi could be established in MDCK cells with the three strains of NDV. Additionally, the Pi was established exclusively by a virulent strain, NDV-Milano. On the other hand, Sendai virus could establish Pi in MDBK and MDCK cell-systems. Several ts mutants were recovered from "late" passages of Pi, and from an accidental infection, a ts mutant with an altered P polypeptide. Ten other ts mutants were tested, however, the specific ts lesion could not be identified. From three Pi in MDCK cells, host range mutants (ts-f1, ts-f2, and ts-f3) were recovered. One of the mutants (ts-f1) has an altered M (matrix) protein. The host range mutants undergo a productive infection in MDBK and MDCK cells, which are nonpermissive for wild type Sendai virus. The possible significance of the results are discussed.

[A study on job stress - making factors and their degrees of stressfulness from the nurses' viewpoint in the university hospitals of Kohgiluyeh and Boyrahmad]

Job stress is a harmful physical and mental response which is due to the interaction between the individual and his environment and lack of agreement between job requirements and the individual's abilities and desires. In addition to damaging the individual, job stress imposes overwhelming expenses on the related organizations. Nursing is one of the occupations in which people are exposed to stress and thus it adversely affects the quality of the services which they offer. So recognition of stress - making factors among nurses can serve as an effective step in determining and reducing stress. The present study was carried out in order to determine the stress- making factors and their degrees of stressfulness from the viewpoint of the nurses working in the hospitals of the University of Medical Sciences in the province. This cross sectional, descriptive, analytical study included 142 nurses who were at work when the study was carried out. A questionnaire was designed for data collection. After coding, the data were analyzed using SPSS software.The most severe stressful factors in nurses proved to be lack of consent with the rate of income [72%], high work- load [61.3], working on holidays [25.9], unacceptability of the profession in the society [51.4], and disturbance of sleep and relaxation [14.1]. Presence of new unfamiliar equipment in the environment and the nurses' lack of skill in working with the equipment [2.4] and lack of skill in the field [14.1] turned out to be the least stress making factors. A comparison between the mean score of stress making factors and the township and the hospital in which they work proved to be statistically significant [p<.004 and p<0.0001]. Spearman correlation coefficient indicated a significant relationship between the number of children and stress [p.01] and between age and stress [p< 0.007]. This study, however, showed no significant relationship between stress and factors such as sex, ward, and record of service, type of employment, status of marriage, income, and being local to the area where they work. Since stress among nurses is potentially harmful and influences their physical and mental abilities and reduces the effectiveness of the service they offer, officials should manage to reduce stress- making factors such as lack of consent with income, work load, etc