The influence of crucible material on the DSC thermal analysis compared to freeze-drying microscopy results

The aim of this study was to investigate the influence of different crucible materials on the thermal analysis of binary systems. The thermal properties of two distinct solutions were measured both by Differential Scanning Calorimetry (DSC) and freeze-drying microscopy and the results were compared. The glass transition of the maximally freeze-concentrate (T (g)`) and the eutectic melting temperature (T (eut)) were not influenced by the crucible material. However the heat of fusion (Delta H) involved during the T (eut) as well as the Delta C (p) involved during the T (g)` of the solutions were affected.

Prostacyclin, not only nitric oxide, is a mediator of the vasorelaxation induced by acetylcholine in aortas from rats submitted to cecal ligation and perforation (CLP)

Nitric oxide has been pointed out as the main agent involved in the vasodilatation, which is the major symptom of septic shock. However, there must be another mediator contributing to the circulatory failure observed in sepsis. This study aimed to investigate the endothelium-dependent relaxation induced by acetylcholine and the factors involved in this relaxation, using aortic rings isolated from rats submitted to cecal ligation and perforation (CLP), 2 h after induction of sepsis, which characterizes the hyperdynamic phase of sepsis. Under inhibition of constitutive NO-synthases (cNOS), the relaxation induced by acetylcholine was greater in the aortic rings of rats submitted to CLP compared with sham-operated rat aortic rings. The cyclooxygenase inhibitor indomethacin normalized this response, and the concentration of the stable metabolite of prostacyclin in the aorta of CLP rats increased in basal conditions and after stimulation with acetylcholine. Acetylcholine-induced NO production was lower in the endothelial cells from the aorta of CLP rats compared with sham rat aorta, but the protein expression of the cNOS was not altered. Moreover, iNOS protein expression could not be detected. Therefore, prostacyclin, and not only nitric oxide, is a mediator of the vasorelaxation induced by acetylcholine in aortas from rats submitted to CLP. (C) 2011 Elsevier Inc. All rights reserved.

Iontophoretic transport of zinc phthalocyanine tetrasulfonic acid as a tool to improve drug topical delivery

Phthalocyanines have been used as systemic photosensitizers because of their high affinity towards tumour tissue, and the high rates of reactive oxygen species produced when they are irradiated during photodynamic therapy. However, the topical administration of these compounds is limited by their large size, poor hydrosolubility and ionic character. This study aimed to investigate the iontophoretic delivery of charged zinc phthalocyanine tetrasulfonic acid (ZnPcS(4)) from a hydrophilic gel to different skin layers by means of in-vitro and in-vivo studies. Six hours of passive administration was insufficient for ZnPcS(4) to cross the stratum corneum (SC) and to reach the epidermis and dermis. No positive effect was reached when anodal iontophoresis was performed, showing that the drug-electrode attraction effect was higher than the electro-osmosis contribution at a pH of 5.5. Cathodal iontophoresis, however, was able to transport significant amounts of the drug to the viable epidermis. In addition, the absence of NaCl in the formulation significantly increased (by five-fold) the amount of ZnPcS(4) that crossed the SC and accumulated in the epidermis and dermis. It was possible to visualize the drug accumulation in the follicle openings and in the epidermis, even after SC removal. In-vivo experiments in rat skin showed that these results were maintained in an in-vivo model, even with only 15 min of iontophoresis. In addition, confocal analysis of the treated skin showed a homogeneous distribution of ZnPcS(4) in the viable epidermis after this short period of cathodal iontophoresis. Anti-Cancer Drugs 22:783-793 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Early Effects on T lymphocyte Response to Iron Deficiency in Mice. Short Communication

Iron deficiency is a common nutritional disorder, affecting about 30% of the world population. Deficits in iron functional compartments have suppressive effects on the immune system. Environmental problems, age, and other nutrient deficiencies are some of the situations which make human studies difficult and warrant the use of animal models. This study aimed to investigate alterations in the immune system by inducing iron deficiency and promoting recuperation in a mouse model. Hemoglobin concentration, hematocrit, liver iron store, and flow cytometry analyses of cell-surface transferrin receptor (CD71) on peripheral blood and spleen CD4+ and CD8+ T lymphocyte were performed in the control (C) and the iron-deficient (ID) groups of animals at the beginning and end of the experiment. Hematological indices of C and ID mice were not different but the iron stores of ID mice were significantly reduced. Although T cell subsets were not altered, the percentage of T cells expressing CD71 was significantly increased by ID. The results suggest that iron deficiency induced by our experimental model would mimic the early events in the onset of anemia, where thymus atrophy is not enough to influence subset composition of T cells, which can still respond to iron deficiency by upregulating the expression of transferrin receptor.

Leukotriene B(4)-loaded microspheres as a new approach to enhance antimicrobial responses in Histoplasma capsulatum-infected mice

Histoplasmosis is a pulmonary disease characterised by chronic granulomatous and suppurative inflammatory reactions caused by Histoplasma capsulatum. Regarding new therapies to control fungal infections, the aim of this study was to investigate whether pulmonary administration of leukotriene B(4) (LTB(4))-loaded microspheres (MS) could confer protection to 5-lipoxygenase knockout (5-LO(-/-)) mice infected by H. capsulatum. In this study, MS containing LTB4 were administered intranasally to mice infected by H. capsulatum. On Day 14 after the infection, fungal recovery from the lungs and histology were evaluated and inflammatory cytokines were measured. Pulmonary administration of LTB(4)-loaded MS was able to reduce fungal recovery from infected lungs. Production of important inflammatory cytokines related to host defence was augmented following MS administration to the lungs. Lung histology also showed that infected mice presented a clear reduction in the fungal burden following the pulmonary release of LTB4 from MS. Our study provides evidence that the proposed biodegradable microparticulate system, which can release LTB4 to the lungs, can be employed as therapy, enhancing the antimicrobial activity of host cells during histoplasmosis. (C) 2009 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.

Exposure to contaminated water: perceptions and practices in a neighborhood in the city of Manaus, Brazil

Objective. To investigate the modes of water supply and the perception concerning the problems caused by this water among residents of a neighborhood without public supply of water, settled in an area previously used as a garbage dump in the city of Manaus, Brazil. Methods. One hundred and sixty-two semi-structured household interviews were conducted. In addition, a focal group with teachers from a local public school and a meeting with residents were held. The instruments employed focused on the perception and modes of water use and on the process of exposure to chemical contaminants through water. Results. Untreated well water was used by most families. This water was considered to be ""good"" by 64.8% of the individuals interviewed. Most residents (88.3%) declared knowledge about the garbage dump. Of these, 77.6% stated that the garbage dump caused health and environmental problems. However, qualitative analysis of the responses revealed that the residents were not aware of contamination by chemical elements or of the consequences of such contamination. The activities carried out with teachers revealed that they were partially aware of the problem, but did not design interventions to address the issue. In a meeting with neighborhood residents, the presence of social activism concerning the problem was identified, but it did not extend beyond the neighborhood or reach governmental spheres. Conclusions. The study identified a situation of critical exposure that tends to be maintained as a result of misperceptions and lack of social mobilization. The dissemination of research results to teachers and residents was useful to empower subjects.

Antibody responses and protective immunity to recombinant vaccinia virus-expressed bluetongue virus antigens

The role of individual viral proteins in the immune response to bluetongue virus (BTV) is not clearly understood. To investigate the contributions of the outer capsid proteins, VP2 and VP5, and possible interactions between them, these proteins were expressed from recombinant vaccinia viruses either as individual proteins or together in double recombinants, or with the core protein VP7 in a triple recombinant. Comparison of the immunogenicity of the vaccinia expressed proteins with BTV expressed proteins was carried out by inoculation of rabbits and sheep. Each of the recombinants was capable of stimulating an anti-BTV antibody response, although there was a wide range in the level of response between animals and species. Vaccinia-expressed VP2 was poorly immunogenic, particularly in rabbits. VP5, on the whole, stimulated higher ELISA titers in rabbits and sheep and in some animals in both species was able to stimulate virus neutralizing antibodies. When the protective efficacy of VP2 and VP5 was tested in sheep, vaccinia-expressed VP2, VP5 and VP2 + VP5 were protective, with the most consistent protection being in groups immunized with both proteins. (C) 1997 Elsevier Science B.V.

A comparison of segmental and wrist-to-ankle methodologies of bioimpedance analysis

The common approach of bioelectrical impedance analysis to estimate body water uses a wrist-to-ankle methodology which, although not indicated by theory, has the advantage of ease of application particularly for clinical studies involving patients with debilitating diseases. A number of authors have suggested the use of a segmental protocol in which the impedances of the trunk and limbs are measured separately to provide a methodology more in keeping with basic theory. The segmental protocol hits not, however, been generally adopted, partly because of the increased complexity involved in its application, and partly because studies comparing the two methodologies have not clearly demonstrated a significant improvement from the segmental methodology. We have conducted a small pilot study involving ten subjects to investigate the efficacy of the two methodologies in a group of normal subjects. The study did not require the independent measure of body water, by for example isotope dilution, as the subjects were maintained in a state of constant hydration with only the distribution between limbs and trunk changing as a result of change in posture. The results demonstrate a significant difference between the two methodologies in predicting the expected constancy of body water in this study, with the segmental methodology indicating a mean percentage change in extracellular water of -2.2%; which was not significantly different from the expected null result, whereas the wrist-to-ankle methodology indicated a mean percentage change in extracellular water of -6.6%. This is significantly different from the null result, and from the value obtained from the segmental methodology (p = 0.006). Similar results were obtained using estimates of total body water from the two methodologies. (C) 1998 Elsevier Science Ltd. All rights reserved.

Economic incentives for farmers in the Philippine uplands to adopt hedgerow intercropping

Land degradation in the Philippine uplands is severe and widespread. Most upland areas are steep, and intense rainfall on soils disturbed by intensive agriculture can produce high rates of soil loss. This has serious implications for the economic welfare of a growing upland population with few feasible livelihood alternatives. Hedgerow intercropping can greatly reduce soil loss from annual cropping systems and has been considered an appropriate technology for soil conservation research and extension in the Philippine uplands. However; adoption of hedgerow intercropping has been sporadic and transient, rarely continuing once external support has been withdrawn. The objective of this paper is to investigate the economic incentives for farmers in the Philippine uplands to adopt hedgerow intercropping relative to traditional open-field maize farming. Cost-benefit analysis is used to compare the economic viability of hedgerow intercropping, as it has been promoted to upland farmers, with the viability of traditional methods of open-field farming. The APSIM and SCUAF models were used to predict the effect of soil erosion on maize yields from open-field farming and hedgerow intercropping. The results indicate that there have been strong economic incentives for farmers with limited planning horizons to reject hedgerow intercropping because the benefits of sustained yields are not realized rapidly enough to compensate for high establishment costs. Alternative forms of hedgerow intercropping such as natural vegetation and grass strips reduce establishment and maintenance costs and are therefore more economically attractive to farmers than hedgerow intercropping with shrub legumes. The long-term economic viability of hedgerow intercropping depends on the economic setting and the potential for hedgerow intercropping to sustain maize production relative to traditional open-field farming. (C) 1998 Academic Press.

Cluster analysis of self-awareness levels in adults with traumatic brain injury and relationship to outcome

The purpose of this study was to investigate the relationship between self-awareness, emotional distress, motivation, and outcome in adults with severe traumatic brain injury. A sample of 55 patients were selected from 120 consecutive patients with severe traumatic brain injury admitted to the rehabilitation unit of a large metropolitan public hospital. Subjects received multidisciplinary inpatient rehabilitation and different types of outpatient rehabilitation and community-based services according to availability and need, Measures used in the cluster analysis were the Patient Competency Rating Scale, Self-Awareness of Deficits Interview, Head Injury Behavior Scale, Change Assessment Questionnaire, the Beck Depression Inventory, and Beck Anxiety Inventory; outcome measures were the Disability Rating Scale, Community Integration Questionnaire, and Sickness Impact Profile. A three-cluster solution was selected, with groups labeled as high self-awareness (n = 23), low self-awareness (n = 23), and good recovery (n = 8). The high self-awareness cluster had significantly higher levels of self-awareness, motivation, and emotional distress than the low self-awareness cluster but did not differ significantly in outcome. Self-awareness after brain injury is associated with greater motivation to change behavior and higher levels of depression and anxiety; however, it was not clear that this heightened motivation actually led to any improvement in outcome. Rehabilitation timing and approach may need to be tailored to match the individual's level of self-awareness, motivation, and emotional distress.

A six-year longitudinal study of the relationship of physical activity to bone mineral accrual in growing children: The University of Saskatchewan bone mineral accrual study

To investigate the influence of physical activity on bone mineral accrual during the adolescent years, we analyzed 6 years of data from 53 girls and 60 boys. Physical activity, dietary intakes, and anthropometry were measured every 6 months and dual-energy X-ray absorptiometry scans of the total body (TB), lumbar spine (LS), and proximal femur (Hologic 2000, array mode) were collected annually. Distance and velocity curves for height and bone mineral content (BMC) were fitted for each child at several skeletal sites using a cubic spline procedure, from which ages at peak height velocity (PHV) and peak BMC velocity (PBMCV) were identified. A mean age- and gender-specific standardized activity (Z) score was calculated for each subject based on multiple yearly activity assessments collected up until age of PHV. This score was used to identify active (top quartile), average (middle 2 quartiles), or inactive (bottom quartile) groups. Two-way analysis of covariance, with height and weight at PHV controlled for, demonstrated significant physical activity and gender main effects (but no interaction) for PBMCV, for BMC accrued for 2 years around peak velocity, and for BMC at 1 year post-PBMCV for the TB and femoral neck and for physical activity but not gender at the LS (all p < 0.05). Controlling for maturational and size differences between groups, we noted a 9% and 17% greater TB BMC for active boys and girls, respectively, over their inactive peers 1 year after the age of PBMCV. We also estimated that, on average, 26% of adult TB bone mineral was accrued during the 2 years around PBMCV.

PAM chlorophyll fluorometry: a new in situ technique for stress assessment in scleractinian corals, used to examine the effects of cyanide from cyanide fishing

Sodium cyanide is being used on reefs in the Asia-Pacific region to capture live fish for the aquarium industry, and to supply a rapidly growing, restaurant-based demand, The effects of cyanide on reef biota have not been fully explored. To investigate its effect on hard corals, we exposed small branch lips of Stylophora pistillata and Acropora aspera to cyanide concentrations estimated to occur during cyanide fishing. Pulse amplitude modulation (PAM) chlorophyll fluorescence techniques were used to examine photoinhibition and photosynthetic electron transport in the symbiotic algae (zooxanthellae) in the tissues of the corals, These measurements were made in situ and in real time using a recently developed submersible PAM fluorometer. In S. pistillata. exposure to cyanide resulted in an almost complete cessation in photosynthetic electron transport rate. Both species displayed marked decreases in the ratio of variable fluorescence (F-v) to maximal fluorescence (F-m) (dark-adapted F-v/F-m), following exposure to cyanide, signifying a decrease in photochemical efficiency. Dark-adapted F-v/F-m recovered to normal levels in similar to 6 d, although intense tissue discolouration, a phenomenon well-recognised as coral 'bleaching' was observed during this period, Bleaching was caused by loss of zooxanthellae from the coral tissues, a well-recognised sub-lethal stress response of corals. Using the technique of chlorophyll fluorescence quenching analysis, corals exposed to cyanide did not show light activation of Calvin cycle enzymes and developed high levels of non-photochemical quenching (q(N)), signifying the photoprotective dissipation of excess light as heat, These features are symptomatic of the known properties of cyanide as an inhibitor of enzymes of the Calvin cycle. The results of this in situ study show that an impairment of zooxanthellar photosynthesis is; the site of cyanide-mediated toxicity, and is the cue that causes corals to release their symbiotic zooxanthellac following cyanide exposure. This study demonstrates the efficacy of PBM fluorometry as a new tool for in situ stress assessment in zooxanthellate scleractinian corals. (C) 1999 Elsevier Science Ltd. All rights reserved.

Sensitivity of multiple frequency bioelectrical impedance analysis to changes in ion status

Bioelectrical impedance analysis has found extensive application as a simple noninvasive method for the assessment of body fluid volumes, The measured impedance is, however, not only related to the volume of fluid but also to its inherent resistivity. The primary determinant of the resistivities of body fluids is the concentration of ions. The aim of this study was to investigate the sensitivity of bioelectrical impedance analysis to bodily ion status. Whole body impedance over a range of frequencies (4-1012 kHz) of rats was measured during infusion of various concentrations of saline into rats concomitant with measurement of total body and intracellular water by tracer dilution techniques. Extracellular resistance (R-o), intracellular resistance (R-i) and impedance at the characteristic frequency (Z(c)) were calculated. R-o and Z(c) were used to predict extracellular and total body water respectively using previously published formulae. The results showed that whilst R-o and Z(c) decreased proportionately to the amount of NaCl infused, R-i increased only slightly. Impedances at the end of infusion predicted increases iu TBW and ECW of approximately 4-6% despite a volume increase of less than 0.5% in TBW due to the volume of fluid infused. These data are discussed in relation to the assumption of constant resistivity in the prediction of fluid volumes from impedance data.

A hybrid, inverse approach to the design of magnetic resonance imaging magnets

This paper describes a hybrid numerical method of an inverse approach to the design of compact magnetic resonance imaging magnets. The problem is formulated as a field synthesis and the desired current density on the surface of a cylinder is first calculated by solving a Fredholm equation of the first, kind. Nonlinear optimization methods are then invoked to fit practical magnet coils to the desired current density. The field calculations are performed using a semi-analytical method. The emphasis of this work is on the optimal design of short MRI magnets. Details of the hybrid numerical model are presented, and the model is used to investigate compact, symmetric MRI magnets as well as asymmetric magnets. The results highlight that the method can be used to obtain a compact MRI magnet structure and a very homogeneous magnetic field over the central imaging volume in clinical systems of approximately 1 m in length, significantly shorter than current designs. Viable asymmetric magnet designs, in which the edge of the homogeneous region is very close to one end of the magnet system are also presented. Unshielded designs are the focus of this work. This method is flexible and may be applied to magnets of other geometries. (C) 2000 American Association of Physicists in Medicine. [S0094-2405(00)00303-5].

Identifying regional dust transport pathways: Application of kinematic trajectory modelling to a trans-Tasman case

PI kinematic trajectory model is used to investigate potential pathways of dust transport from Australia to New Zealand. Historically, these have been assumed to follow rather direct west-east trajectories spanning 2 to 3 days, often resulting in red snow events in the Southern Alps of New Zealand. However, results from the present study which examined the route taken by air parcels originating in southern Australia during dust storms on 24 and 25 May 1994, indicate that trans-Tasman dust transport trajectories are more diverse than previously thought, and display considerable variation during single events. These mon divergent pathways tie in more closely with aeolian dust sedimentation patterns identified by ocean coring in the Tasman Sea, and may account for the deposition of Australian dust on sub-Antarctic islands located well south of the Australian continent. Copyright 2000 John Wiley Sons, Ltd.