Retrospective Validation of a Computer-Assisted Quantification Model of Intracerebral Hemorrhage Volume on Accuracy, Precision, and Acquisition Time, Compared with Standard ABC/2 Manual Volume Calculation.

BACKGROUND AND PURPOSE: Intracerebral hemorrhage accounts for 6.5%-19.6% of all acute strokes. Initial intracerebral hemorrhage volume and expansion are both independent predictors of clinical outcomes and mortality. Therefore, a rapid, unbiased, and precise measurement of intracerebral hemorrhage volume is a key component of clinical management. The most commonly used method, ABC/2, results in overestimation. We developed an interactive segmentation program, SegTool, using a novel graphic processing unit, level set algorithm. Until now, the speed, bias, and precision of SegTool had not been validated. MATERIALS AND METHODS: In a single stroke academic center, 2 vascular neurologists and 2 neuroradiologists independently performed a test-retest experiment that involved repeat measurements of static, unchanging intracerebral hemorrhage volumes on CT from 76 intracerebral hemorrhage cases. Measurements were made with SegTool and ABC/2. True intracerebral hemorrhage volumes were estimated from a consensus of repeat manual tracings by 2 operators. These data allowed us to estimate measurement bias, precision, and speed. RESULTS: The measurements with SegTool were not significantly different from the true intracerebral hemorrhage volumes, while ABC/2 overestimated volume by 45%. The interrater measurement variability with SegTool was 50% less than that with ABC/2. The average measurement times for ABC/2 and SegTool were 35.7 and 44.6 seconds, respectively. CONCLUSIONS: SegTool appears to have attributes superior to ABC/2 in terms of accuracy and interrater reliability with a 9-second delay in measurement time (on average); hence, it could be useful in clinical trials and practice.

Using Positive Deviance in the prevention and control of MRSA infections in a Colombian hospital: a time-series analysis.

Positive Deviance (PD) is a process to achieve a social and cultural change. This strategy has been used for the control of methicillin-resistant Staphylococcus aureus (MRSA) infection in some health institutions in the United States, but has rarely been adopted in institutions from developing countries where resources are limited. We describe our experience of PD in the control of healthcare-associated infections (HAIs) due to MRSA in a Colombian hospital with the aim of reducing HAI rates through a cultural change in processes. A time-series study was conducted based on the MRSA-HAI rate and the number of months with zero MRSA infections before and after application of PD (2001-2012). On comparing the pre-intervention and intervention periods, the mean overall rates of MRSA-HAI was 0·62 and 0·36, respectively (P = 0·0005); the number of months with zero MRSA-HAIs were 3/70 and 12/74 (odds ratio 0·264, 95% confidence interval 0·078-0·897); the percentage of MRSA-HAIs was 53·2% and 41·0%. These results are consistent with other published data. Implementation of PD was associated with a significant reduction of MRSA-HAIs, it did not involve high costs and the changes have been lasting.

A self-assembling ß-peptide hydrogel for neural tissue engineering.

We report a new class of ß-peptide based hydrogel for neural tissue engineering. Our ß-peptide forms a network of nanofibres in aqueous solution, resulting in a stable hydrogel at physiological conditions. The hydrogel shows excellent compatibility with neural cells and provides a suitable environment for cells to adhere and proliferate.

Phytophthora Crown and Root Rot of Zucchini Squash in Almería, Spain.

Zucchini (Cucurbita pepo) is intensively cropped in approximately 4,500 ha of plastic houses in southern Spain. In 2008 to 2009, Consul, Cronos, and Tosca zucchini plants showed symptoms of leaf wilting, basal stem necrosis, and plant death. Incidences of dead plants were 20 to 30% and these plants were distributed in clusters. Phytophthora capsici Leonian was isolated from the basal stems of symptomatic plants, using PDA and cornmeal agar amended with a pimaricin, ampicillin, and rifampicin. Five resultant isolates (PCl-211, PCl-221, PCl-611, PCl-612, and PCl-811) on lima beans agar (LBA) produced white mycelia with lemon-shaped and papillate sporangia borne on long pedicels, but no oospores or chlamydospores. These isolates had an identical ribosomal DNA ITS sequence, matching with that of P. capsici in GenBank. The sequences of two representative isolates, PCl-211 and PCl-811, were deposited in GenBank with accession nos. KC662328 and KC688317, respectively. The pathogenicity of these five isolates was tested on zucchini cv. Consul in 1-liter containers filled with vermiculite in May and September of 2009. Plants were inoculated at the 2 to 3 true-leaf stage. Plates with LBA fully covered with colony of each isolate were separately blended and homogenized with 300 ml of sterile distilled water. Inocula were poured around stem at 50 ml per plant. Each experiment had three replicates and four plants per replicate. Treatments with different isolates were arranged in a randomized complete block design. In both experiments, 12 uninoculated plants served as controls. Test plants were maintained for a month following inoculation in a greenhouse with mean temperatures ranging from 21.9 to 27.9°C and from 20.7 to 24.6°C for the May and September experiments, respectively. The first wilting occurred 5 days after inoculation. At the end of the May experiment, all control plants and those inoculated with PCl-221 remained asymptomatic while 83.3% of those inoculated with PCl-211 and 100% of those with the other isolates were dead. Inoculated plants exhibited crown and root rots, excluding the secondary roots. In the September experiment, 83.3% and 33.3% of plants inoculated with PCl-211 and PCl-221, respectively, were symptomatic, while all plants inoculated with the other isolates were dead. The control plants remained healthy. The pathogen was consistently recovered from symptomatic plants in both experiments. Although P. capsici was reported in peppers (Capsicum annuum) in several provinces of Spain (1), to our knowledge, this is the first report of P. capsici as the causal agent of crown rot in zucchini plants in plastic houses in the Almería Province of Spain, one of the world's largest concentrations of greenhouses. Reference: (1) J. L. Andrés et al. Span J Agric Res 3:326, 2005.

First Report of Phaeoacremonium krajdenii Causing Petri Disease of Grapevine in Spain.

In September 2009, symptoms of grapevine (Vitis vinifera L.) decline were observed on 3-year-old grapevines in a vineyard in Roquetas de Mar (Almeria Province, southern Spain). Affected vines were weak with reduced foliage and chlorotic leaves. Black spots and dark streaking of the xylem vessels could be seen in cross- or longitudinal sections of the rootstock trunk. Symptomatic plants were collected and sections (10 cm long) were cut from the basal end of the rootstocks, washed under running tap water, surface disinfested for 1 min in a 1.5% sodium hypochlorite solution, and washed twice with sterile distilled water. The sections were split longitudinally and small pieces of discolored tissues were plated onto malt extract agar (MEA) supplemented with 0.5 g liter-1 of streptomycin sulfate. Dishes were incubated at 25 to 26°C in the dark for 14 to 21 days, and all colonies were transferred to potato dextrose agar (PDA). A Phaeoacremonium sp. was consistently isolated from necrotic tissues. Single conidial isolates were obtained and grown on PDA and MEA in the dark at 25°C for 2 to 3 weeks until colonies produced spores (2). Colonies were grayish brown on PDA and dark brown on MEA. Conidiophores were short and unbranched and 11.5 to 46 (25.5) µm long. Phialides were often polyphialidic. Conidia were hyaline, oblong-ellipsoidal or allantoid, 2.5 to 5 (4.2) µm long, and 1 to 1.7 (1.2) µm wide. On the basis of these characters, the isolates were identified as Phaeoacremonium krajdenii L. Mostert, Summerb. & Crous (1,2). DNA sequencing of a fragment of the beta-tubulin gene of the isolate (Pkr-1) using primers T1 and Bt2b (GenBank Accession No. HM637892) matched P. krajdenii GenBank Accession No. AY579330. Pathogenicity tests were conducted using isolate Pkr-1. Ten 1-year-old callused and rooted cuttings of 110 R rootstock grown in pots with sterile peat were wounded at the uppermost internode with an 8-mm cork borer. A 5-mm mycelium PDA plug from a 2-week-old culture was placed in the wound before being wrapped with Parafilm. Ten control plants were inoculated with 5-mm noncolonized PDA plugs. Plants were maintained in a greenhouse at 25 to 30°C. Within 3 months, shoots on all Phaeoacremonium-inoculated cuttings had weak growth with small leaves and short internodes and there were black streaks in the xylem vessels. The vascular necroses that developed on the inoculated plants were 5.5 ± 1.2 cm long, significantly greater than those on the control plants (P < 0.01). Control plants did not show any symptoms. The fungus was reisolated from discolored tissue of all inoculated cuttings, completing Koch's postulates. P. krajdenii has a worldwide distribution, although these reports are from human infections (1). P. krajdenii was first reported as a pathogen of grapevines in South Africa (1). To our knowledge, this is the first report of P. krajdenii causing young grapevine decline in Spain or any country in Europe. References: (1) L. Mostert et al. J. Clin. Microbiol. 43:1752, 2005. (2) L. Mostert et al. Stud. Mycol. 54:1, 2006.

First Report of Campylocarpon fasciculare Causing Black Foot Disease of Grapevine in Spain.

In May 2008, symptoms of black foot disease were observed on 8-year-old grapevines (Vitis vinifera L.) cv. Garnacha in Albuñol (Granada Province, southern Spain). Affected plants showed delayed budding with low vigor. Roots showed black discoloration and necrosis of wood tissues. Root fragments were cut, washed under running tap water, surface sterilized for 1 min in a 1.5% sodium hypochlorite solution, and washed twice with sterile distilled water. Small pieces of discolored or necrotic tissues were plated onto potato dextrose agar (PDA) supplemented with 0.5 g liter-1 of streptomycin sulfate. Plates were incubated at 25°C in the dark for 10 days and all colonies were transferred to PDA. A Cylindrocarpon-like fungus was consistently isolated from necrotic root tissues. Single conidial isolates were obtained and grown on PDA and Spezieller Nährstoffarmer Agar (SNA) and incubated at 25°C for 10 days in darkness. On PDA, the isolates developed white, thick, and cottony to felty abundant mycelium. On SNA, all isolates produced slightly to moderately curved one-septate (22.5-) 25.6 (-27.5) × (5-) 5.63 (-6.25) µm, two-septate (30-) 36.1 (-45) × (6.25-) 7.08 (-7.5) µm, three-septate (37.5-) 47.9 (-52.5) × (6.25-) 7.5 (-8.75) µm, four-septate (47.5-) 53.3 (-62.5) × (7.5-) 7.89 (-8.75) µm, and five-septate (52.5-) 61.8 (-67.5) × (7.5-) 8 (-8.75) µm macroconidia. Microconidia were not observed. DNA sequence of the rDNA internal transcribed spacer region (ITS) was obtained for isolate Cf-270 and deposited in GenBank (Accession No. HQ441249). This sequence showed high similarity (99%) to the sequence of Campylocarpon fasciculare Schroers, Halleen & Crous (GenBank Accession No. AY677303), in agreement with morphological features (1). Pathogenicity tests were conducted with inoculum produced on wheat (Triticum aestivum L.) seeds that were soaked for 12 h in flasks filled with distilled water. Each flask contained 300 ml of seeds that were subsequently autoclaved three times after excess water was drained. Two fungal disks of a 2-week-old culture of C. fasciculare (isolate Cf-270) grown on PDA were placed aseptically in each flask. The flasks were incubated at 25°C for 4 weeks and shaken once a week to avoid clustering of inoculum. Plastic pots (220 cm3) were filled with a mixture of sterilized peat moss and 10 g of inoculum per pot. One-month-old grapevine seedlings were planted individually in each pot and placed in a greenhouse at 25 to 30°C in a completely randomized design. Control plants were inoculated with sterile uninoculated seeds. Six replicates (each one in individual pots) were used, with an equal number of control plants. The experiment was repeated. Symptoms developed on all plants 20 days after inoculation and consisted in reduced vigor, interveinal chlorosis and necrosis of the leaves, necrotic root lesions with a reduction in root biomass, and plant death. The fungus was reisolated from the roots of affected seedlings and identified as C. fasciculare, completing Koch's postulates. No symptoms were observed on the control plants. Black foot disease of grapevines can be caused by different species of Cylindrocarpon and Campylocarpon. C. fasciculare was first reported in South Africa in 2004 (1). To our knowledge, this is the first report of C. fasciculare causing black foot disease of grapevine in Spain as well as other countries in Europe. Reference: (1) F. Halleen et al. Stud. Mycol. 50:431, 2004.

Albuminuria and the risk of incident stroke and stroke types in older adults.

BACKGROUND: The kidney biomarker that best reflects risk of stroke is unknown. We sought to evaluate the association of stroke with 3 kidney biomarkers: albuminuria, cystatin C, and glomerular filtration rate. METHODS: These 3 biomarkers were determined in 3,287 participants without history of stroke from the Cardiovascular Health Study, a longitudinal cohort study of men and women age 65 years and older from 4 US communities. The biomarkers were albuminuria ascertained using urinary albumin-to-creatinine ratio (UACR) from morning spot urine, creatinine-based estimated glomerular filtration rate (eGFR), and cystatin C. Outcomes were incident stroke (any, ischemic, or hemorrhagic) during follow-up between 1996 and 2006. RESULTS: A total of 390 participants had an incident stroke: 81% ischemic, 12% hemorrhagic, and 7% unclassified. In adjusted Cox regression models, UACR was more strongly related to any stroke, ischemic stroke, and hemorrhagic stroke than eGFR and cystatin C. The hazard ratio (HR) of any stroke comparing the top to bottom quintile of UACR was 2.10 (95% confidence interval [CI] 1.47-3.00), while HR for eGFR was 1.29 (95% CI 0.91-1.84) and for cystatin C was 1.22 (95% CI 0.85-1.74). When considering clinically relevant categories, elevated UACR was associated with increased hazard of any stroke and ischemic stroke regardless of eGFR or cystatin C categories. CONCLUSIONS: UACR was the kidney biomarker most strongly associated with risk of incident stroke. Results in this elderly cohort may not be applicable to younger populations. These findings suggest that measures of glomerular filtration and permeability have differential effects on stroke risk.

Effect of the aeration system on the levels of airborne microorganisms generated at wastewater treatment plants.

Six different wastewater treatment plants were monitored in order to identify the main bioaerosol sources and to evaluate the effect of the aeration system used in the biological treatment (air diffusion, horizontal rotors and surface turbine aerators) on the airborne microorganism levels to which workers may be exposed. Air samples were collected by using a single stage impactor. Total count of mesophilic bacteria was used as the monitoring parameter to compare the impact of the aeration system on generic bacterial bioaerosols rather than a quantitative estimation for pathogens or fecal indicator microbes. In this study, pre-treatment, biological treatment and sludge thickening were the processes that generated the highest amount of bioaerosols. Aeration systems involving mechanical agitation of the wastewater, such as horizontal rotors and surface turbines, generated a larger amount of bioaerosols (between 450 and 4580CFU/m(3)) than air diffuser aerators (between 22 and 57CFU/m(3)). The levels of airborne bacteria generated by air diffusers were very similar to those registered at the background locations (lower than 50CFU/m(3)), unaffected by the activities taking place in the wastewater treatment plant. The use of air diffusers as an aeration system for the biological treatment would significantly minimise the potential biological hazard that wastewater treatment plant workers may be exposed to.

Oral anticoagulants versus antiplatelet therapy for preventing stroke in patients with non-valvular atrial fibrillation and no history of stroke or transient ischemic attacks.

BACKGROUND: Non-valvular atrial fibrillation (AF) carries an increased risk of stroke mediated by embolism of stasis-precipitated thrombi originating in the left atrial appendage. Both oral anticoagulants and antiplatelet agents have proven effective for stroke prevention in most patients at high risk for vascular events, but primary stroke prevention in patients with non-valvular AF potentially merits separate consideration because of the suspected cardio-embolic mechanism of most strokes in AF patients. OBJECTIVES: To characterize the relative effect of long-term oral anticoagulant treatment compared with antiplatelet therapy on major vascular events in patients with non-valvular AF and no history of stroke or transient ischemic attack (TIA). SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (June 2006). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 2, 2006), MEDLINE (1966 to June 2006) and EMBASE (1980 to June 2006). We contacted the Atrial Fibrillation Collaboration and experts working in the field to identify unpublished and ongoing trials. SELECTION CRITERIA: All unconfounded, randomized trials in which long-term (more than four weeks) adjusted-dose oral anticoagulant treatment was compared with antiplatelet therapy in patients with chronic non-valvular AF. DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials for inclusion, assessed quality and extracted data. The Peto method was used for combining odds ratios after assessing for heterogeneity. MAIN RESULTS: Eight randomized trials, including 9598 patients, tested adjusted-dose warfarin versus aspirin (in dosages ranging from 75 to 325 mg/day) in AF patients without prior stroke or TIA. The mean overall follow up was 1.9 years/participant. Oral anticoagulants were associated with lower risk of all stroke (odds ratio (OR) 0.68, 95% confidence interval (CI) 0.54 to 0.85), ischemic stroke (OR 0.53, 95% CI 0.41 to 0.68) and systemic emboli (OR 0.48, 95% CI 0.25 to 0.90). All disabling or fatal strokes (OR 0.71, 95% CI 0.59 to 1.04) and myocardial infarction (OR 0.69, 95% CI 0.47 to 1.01) were substantially but not significantly reduced by oral anticoagulants. Vascular death (OR 0.93, 95% CI 0.75 to 1.15) and all cause mortality (OR 0.99, 95% CI 0.83 to 1.18), were similar with these treatments. Intracranial hemorrhages (OR 1.98, 95% CI 1.20 to 3.28) were increased by oral anticoagulant therapy. AUTHORS' CONCLUSIONS: Adjusted-dose warfarin and related oral anticoagulants reduce stroke, disabling stroke and other major vascular events for those with non-valvular AF by about one third when compared with antiplatelet therapy.

Oral anticoagulants for preventing stroke in patients with non-valvular atrial fibrillation and no previous history of stroke or transient ischemic attacks.

BACKGROUND: Non-valvular atrial fibrillation (AF) is associated with an increased risk of stroke mediated by embolism of stasis-precipitated thrombi from the left atrial appendage. OBJECTIVES: The objective is to characterize the efficacy and safety of oral anticoagulants (OACs) for the primary prevention of stroke in patients with chronic AF. SEARCH STRATEGY: We searched the Cochrane Stroke Group Trials Register (last searched in June 2004). In addition, we searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2004), MEDLINE (1966 to June 2004), and the reference lists of recent review articles. We also contacted the Atrial Fibrillation Collaboration and experts working in the field to identify unpublished and ongoing trials. SELECTION CRITERIA: All randomized controlled trials comparing OACs with control in patients with chronic non-valvular atrial fibrillation and no history of transient ischemic attack (TIA) or stroke. DATA COLLECTION AND ANALYSIS: Trials for inclusion were independently selected by two authors who also extracted each outcome and double-checked the data. The Peto method was used for combining odds ratios. All analysis were, as far as possible, intention-to-treat. Since the published results of four trials included 3% to 8% of participants with prior stroke or TIA, unpublished results excluding these participants were obtained from the Atrial Fibrillation Investigators. MAIN RESULTS: Of 2313 participants without prior cerebral ischemia from five randomized trials, the mean age was 69 years. Participant features and study quality were similar between trials: the OAC in all five trials was warfarin. About half of participants (n = 1154) were randomized to adjusted-dose warfarin with mean achieved INRs ranging between 2.0 to 2.6. During 1.5 years mean follow up, warfarin was associated with large, highly statistically significant reductions in all strokes (odds ratio (OR) 0.39, 95% confidence interval (CI) 0.26 to 0.59), ischemic stroke (OR 0.34, 95% CI 0.23 to 0.52), all disabling or fatal stroke (OR 0.47, 95% CI 0.28 to 0.80), death (OR 0.69, 95% CI 0.50 to 0.94) and the combined endpoint of all stroke, myocardial infarction or vascular death (OR 0.56, 95% CI 0.42 to 0.76). The observed rates of intracranial and extracranial hemorrhage were not significantly increased by OAC therapy, but the confidence intervals were wide. AUTHORS' CONCLUSIONS: Treatment with adjusted-dose warfarin to achieved INRs of 2 to 3 reduces stroke, disabling or fatal stroke, and death for patients with non-valvular AF. The benefits were not substantially offset by increased bleeding among these participants in randomized clinical trials. Limitations include relatively short follow up and imprecise estimates of bleeding risks from the selected participants enrolled in the trials. For primary prevention of stroke in AF patients, about 25 strokes and about 12 disabling or fatal strokes would be prevented yearly for every 1000 atrial fibrillation patients given OACs.

Improvement of coagulation-flocculation process using anionic polyacrylamide as coagulant aid.

A physicochemical treatment (coagulation-flocculation) was applied to a slaughterhouse wastewater, using anionic polyacrylamide as coagulant aid to improve the settling velocity of the flocs formed with the coagulants used: ferric sulphate, aluminium sulphate and polyaluminium chloride. The optimum speed and stirring time for the flocculation stage were ascertained along with the optimum pH and coagulant and coagulant aid doses. The speed and coagulation time were initially set according to recommendations in the literature concerning the treatment of this type of water. Chemical oxygen demand (COD), biochemical oxygen demand at 5 days (BOD5) and total suspended solids (TSS) were recorded at the beginning and end of each experiment in order to monitor the process. Once the optimal conditions had been established, several parameters were measured in order to assess the coagulation-flocculation process: particle number and size, sludge volume, nutrients (ammonia nitrogen, total Kjeldahl nitrogen, albuminoid nitrogen, orthophosphate, total phosphorus) and the residual concentration of iron and aluminium in clarified water. Anionic polyacrylamide, when added with ferric sulphate or polyaluminium chloride led to a significant increase in the settling speed.

Alpha7-nicotinic acetylcholine receptors mediate an Abeta(1-42)-induced increase in the level of acetylcholinesterase in primary cortical neurones.

The beta-amyloid protein (Abeta) is the major protein component of amyloid plaques found in the Alzheimer brain. Although there is a loss of acetylcholinesterase (AChE) from both cholinergic and non-cholinergic neurones in the brain of Alzheimer patients, the level of AChE is increased around amyloid plaques. Previous studies using P19 cells in culture and transgenic mice which overexpress human Abeta have suggested that this increase may be due to a direct action of Abeta on AChE expression in cells adjacent to amyloid plaques. The aim of the present study was to examine the mechanism by which Abeta increases levels of AChE in primary cortical neurones. Abeta1-42 was more potent than Abeta1-40 in its ability to increase AChE in primary cortical neurones. The increase in AChE was unrelated to the toxic effects of the Abeta peptides. The effect of Abeta1-42 on AChE was blocked by inhibitors of alpha7 nicotinic acetylcholine receptors (alpha7 nAChRs) as well as by inhibitors of L- or N-type voltage-dependent calcium channels (VDCCs), whereas agonists of alpha7 nAChRs (choline, nicotine) increased the level of AChE. The results demonstrate that the effect of Abeta1-42 on AChE is due to an agonist effect of Abeta1-42 on the alpha7 nAChR.

The membrane-binding properties of a class A amphipathic peptide.

The membrane-binding properties of a class A amphipathic peptide (18D) were investigated using two different immobilized model membrane systems. The first system involved the use of surface plasmon resonance (SPR) to study the binding of 18D to dimyristylphosphatidylcholine (DMPC) and dimyristylphosphatidylglycerol (DMPG), which allowed peptide binding to be monitored in real time. The SPR experiments indicated stronger binding of 18D to DMPG than DMPC, which kinetic analysis revealed was due to a faster on-rate. The second model membrane system involved immobilized membrane chromatography in which the binding of 18D to either DMPC or DMPG monolayers covalently linked to silica particles was analysed by elution chromatography. Stronger binding affinity of 18D was also obtained with the negatively charged phosphatidylglycerol (PG) monolayer compared to the phosphatidylcholine (PC) monolayer, which was consistent with the SPR results. Non-linear binding behaviour of 18D to the immobilized lipid monolayers was also observed, which suggests that the peptide undergoes conformational and orientational changes upon binding to the immobilized PC and PG ligands. Significant band broadening was also observed on both monolayers, with larger bandwidths obtained on the PC surface, indicating slower binding and orientation kinetics with the zwitterionic surface. The dependence of logk' on the percentage of methanol also demonstrated a bimodal interaction whereby hydrophobic forces predominated at higher temperatures and methanol concentrations, while at lower temperatures, electrostatic and other polar forces also made a contribution to the affinity of the peptides for the lipid monolayer particularly. Overall, these results demonstrate the complementary use of these two lipid biosensors which allows the role of hydrophobic and electrostatic forces in peptide-membrane interactions to be studied and insight gained into the kinetic factors associated with these interactions.

Microscopic observation of particle reduction in slaughterhouse wastewater by coagulation-flocculation using ferric sulphate as coagulant and different coagulant aids.

A coagulation-flocculation treatment has been applied to a slaughterhouse liquid effluent, using ferric sulphate as coagulant and activated silica, powdered activated carbon, cationic polyacrylamide, polyvinyl alcohol, polyacrylic acid and anionic polyacrylamide as coagulant aids in order to improve the settling time. Once the optimal conditions had been established (speed and time of stirring during flocculation step, pH, coagulant and coagulant aid doses), the efficiency of the coagulation-flocculation process was studied by comparing the particle size distribution before and after the addition of the coagulant. When ferric sulphate was used without the coagulant aids, particle removal efficiency varied with size, although overall efficiency was quite substantial (87%). The use of coagulant aids improved the removal efficiency, except in the case of activated silica, when it fell to 78%. In all other cases removal efficiency values between 93% (for polyvinyl alcohol) and 99% (for anionic polyacrylamide) were reached.

Nutrient removal and sludge production in the coagulation-flocculation process.

Nutrient removal and sludge production in the coagulation-flocculation process, applied to a slaughterhouse effluent, have been studied. Fe2(SO4)3, Al2(SO4)3 and polyaluminium chloride were used as coagulants. Inorganic products were used as coagulant aids: activated silica, powdered activated carbon and precipitated calcium carbonate and synthetic polyelectrolytes: cationic polyacrylamide, polyacrilic acid, anionic polyacrylamide and polyvinyl alcohol. Performances were measured under optimum conditions for the products used. They were found after studying the different variables which influence the process. Phosphorus removal is very high (approximately 100% for the orthophosphate and between 98.93% and 99.90% for the total phosphorus). Ammonia nitrogen removal is very low although appreciable performances are observed for albuminoid nitrogen (73.9-88.77%). The use of coagulant aids reduces the volume of the sludge produced up to 41.6%.

Analysis of the peripheral immune response in patients with neurocysticercosis: evidence for T cell reactivity to parasite glycoprotein and vesicular fluid antigens.

In neurocysticercosis (NCC), it is thought that the long-term survival of the parasite within the human brain is due in part to the ability of the cestode to suppress the local immune response. When the parasite dies, the immunosuppression is apparently lost and a strong local inflammatory response then develops. In contrast, little is known about the immunologic response that may occur in the peripheral immune system of these patients. In this study, the status of the peripheral (extracerebral) cellular and humoral response was evaluated in patients with a history of NCC. The in vitro proliferation of peripheral blood mononuclear cells to mitogens and foreign antigens was similar in patients and controls. Importantly, a substantive response was elicited by two Taenia solium metacestode antigens. In addition, 8 of 10 patients had a detectable humoral response to the antigenic glycoproteins of the cestode. Considering both the cellular and humoral response, all of the patients with NCC presented an active peripheral immunity.

Bioactive compounds from Iostephane heterophylla (Asteraceae).

The novel bisabolene sesquiterpenes 3-6, were isolated from Iostephane heterophylla, using bioguided fractionation. The new compounds were determined to be (12R/12S)-12,13-epoxy-xanthorrhizols (3,4) and (12R/12S)-12,13-dihydro-12,13-dihydroxy-xanthorrizols (5,6) and their structures were characterized by analysis of spectroscopic data and by chemical correlation from xanthorrhizol (2). The stereochemistry at C-12 of 5 was deduced using the modified Mosher experiment. Some of the isolated compounds elicited activity against gram positive and gram negative bacteria, levadura and dermatophytes.

Analysis of antimicrobial peptide interactions with hybrid bilayer membrane systems using surface plasmon resonance.

The lipid binding behaviour of the antimicrobial peptides magainin 1, melittin and the C-terminally truncated analogue of melittin (21Q) was studied with a hybrid bilayer membrane system using surface plasmon resonance. In particular, the hydrophobic association chip was used which is composed of long chain alkanethiol molecules upon which liposomes adsorb spontaneously to create a hybrid bilayer membrane surface. Multiple sets of sensorgrams with different peptide concentrations were generated. Linearisation analysis and curve fitting using numerical integration analysis were performed to derive estimates for the association (k(a)) and dissociation (k(d)) rate constants. The results demonstrated that magainin 1 preferentially interacted with negatively charged dimyristoyl-L-alpha-phosphatidyl-DL-glycerol (DMPG), while melittin interacted with both zwitterionic dimyristoyl-L-alpha-phosphatidylcholine and anionic DMPG. In contrast, the C-terminally truncated melittin analogue, 21Q, exhibited lower binding affinity for both lipids, showing that the positively charged C-terminus of melittin greatly influences its membrane binding properties. Furthermore the results also demonstrated that these antimicrobial peptides bind to the lipids initially via electrostatic interactions which then enhances the subsequent hydrophobic binding. The biosensor results were correlated with the conformation of the peptides determined by circular dichroism analysis, which indicated that high alpha-helicity was associated with high binding affinity. Overall, the results demonstrated that biosensor technology provides a new experimental approach to the study of peptide-membrane interactions through the rapid determination of the binding affinity of bioactive peptides for phospholipids.