Flocculent Material Research Articles

A Toxicological, Histological, and Biochemical Study of the Effect of Aroclor 1254 on Thyroid Follicular Cells and the Possible Protective Role of Zinc Sulphate in Adult Male Albino Rats

Introduction: Aroclor 1254 is a commercial mixture of polychlorinated biphenyls used in transformers, capacitors, paints, pesticides and others. The effect of Aroclor 1254 on endocrine system, especially thyroid gland has been a point of research interest. Aim of the work: The present study was, therefore designed specifically to investigate the possible toxic effect of Aroclor 1254 on thyroid follicular cells of adult male albino rats and to assess the possible protective role of zinc sulphate. Material and methods: The study was carried out on 45 adult male albino rats that were randomly divided into 3 equal groups. Group I or the control group, which was further, divided into 3 equal subgroups, (5 rats each): received either normal saline or corn oil or zinc sulphate, respectively, orally for 4 weeks. Group II: Aroclor 1254 dissolved in corn oil in a dose of 4mg /kg.b.w/day for 4 weeks. Group III: received Aroclor 1254 dissolved in corn oil in a dose of 4mg /kg.b.w/day with concomitant administration of zn sulphate at a dose of 200mg/kg.b.w/day for 4 weeks. After 28 days, the animals were sacrificed and blood samples were subjected to hormonal assay for T3, T4 and TSH levels. Malondialedehyde (MDA) and reduced glutathione (GSH) were also assessed. Results: Biochemical assays showed a significant decrease in serum GSH, total antioxidant capacity, T3 and T4 levels in the aroclor treated group than both control and protected group. On contrary, a significant increase in serum MDA and TSH levels was recorded in Aroclor treated group than other two groups. Microscopic examination of thyroid gland follicles in Aroclor 1254 treated rats revealed evident histological changes. Most of the follicles appeared smaller compared to the control group. Excessive vacuolation of the colloid at the interphase with the lining epithelial cells was seen. Moreover, most of the follicles appeared lined with high cuboidal epithelial cells with foci of epithelial hyperplasia. Ultrastructural alterations in follicular cells were detected which appeared as high columnar cells with irregular microvilli. Numerous rough endoplasmic reticulum with extensively dilated cisternae that were filled with flocculent material were demonstrated. On examination of the group III, a marked improvement in the histological features of thyroid follicles was noticed. Conclusion: These results suggest that PCB induces oxidative stress in rats as well as hypothyroidism; these effects could be reversed by the administration of zinc sulphate. The decrease in T3 and T4 levels induced compensatory effects in the thyroid, visible as hyperactivity of the thyroid epithelia.

Explosibility of polyamide and polyester fibers

The current research is aimed at investigating the explosion behavior of hazardous materials in relation to aspects of particulate size. The materials of study are flocculent (fibrous) polyamide 6.6 (nylon) and polyester (polyethylene terephthalate). These materials may be termed nontraditional dusts due to their cylindrical shape which necessitates consideration of both particle diameter and length. The experimental work undertaken is divided into two main parts. The first deals with the determination of deflagration parameters for polyamide 6.6 (dtex 3.3) for different lengths: 0.3 mm, 0.5 mm, 0.75 mm, 0.9 mm and 1 mm; the second involves a study of the deflagration behavior of polyester and polyamide 6.6 samples, each having a length of 0.5 mm and two different values of dtex, namely 1.7 and 3.3. (Dtex or decitex is a unit of measure for the linear density of fibers. It is equivalent to the mass in grams per 10,000 m of a single filament, and can be converted to a particle diameter.) The explosibility parameters investigated for both flocculent materials include maximum explosion pressure (Pmax), size-normalized maximum rate of pressure rise (KSt), minimum explosible concentration (MEC), minimum ignition energy (MIE) and minimum ignition temperature (MIT). ASTM protocols were followed using standard dust explosibility test equipment (Siwek 20-L explosion chamber, MIKE 3 apparatus and BAM oven). Both qualitative and quantitative analyses were undertaken as indicated by the following examples. Qualitative observation of the post-explosion residue for polyamide 6.6 indicated a complex interwoven structure, whereas the polyester residue showed a shiny, melt-type appearance. Quantitatively, the highest values of Pmax and KSt were obtained at the shortest length and finest dtex for a given material. For a given length, polyester displayed a greater difference in Pmax and KSt at different values of dtex than polyamide 6.6. Long ignition delay times were observed in the BAM oven (MIT measurements) for polyester, and video framing of explosions in the MIKE 3 apparatus (MIE measurements) enabled observation of secondary ignitions caused by flame propagation after the initial ignition occurring at the spark electrodes.

Modelling of the effect of size on flocculent dust explosions

The effect of size on the severity of explosions involving flocculent materials has been simulated by means of a model previously developed for spherical particles and here extended to the cylindrical geometry of flock. The model consists of the identification of the regime (internal and external heating, pyrolysis/devolatilization reaction, and volatiles combustion) controlling the explosion by the evaluation of dimensionless numbers (Bi, Da, Th and Pc) and then of the estimation of the deflagration index as a function of flocculent size. The model has been validated by means of explosion data of polyamide 6.6 (nylon) at varying diameter and length. The comparison between model and experimental data show a fairly good agreement.

Fatal Barium Chloride Poisoning

Barium is an alkaline earth metal which has a variety of uses including in the manufacturing industry and in medicine. However, adverse health effects and fatalities occur due to absorption of soluble barium compounds, notably the chloride, nitrate, and hydroxide, which are toxic to humans. Although rare, accidental and suicidal modes of poisoning are sporadically reported in the literature.We describe 4 cases of poisoning due to barium chloride in China. In witnessed cases, severe gastrointestinal symptoms, hypokalemia leading to muscle weakness, cardiac arrhythmias, and respiratory failure were noted. Autopsy showed some nonspecific but common findings, such as subendocardial hemorrhage in the ventricles, visceral petechiae, and fatty changes in the liver. Interestingly, microscopic examination showed degenerative changes and amorphous, flocculent foamy materials in the renal tubules. Toxicology was relevant for barium in blood and tissues. Three of the cases were accidental and 1 homicidal in nature. A round-up of relevant literature on fatal barium compounds poisoning is also provided. Forensic pathologists should be aware of the clinical presentations of barium compound poisoning and especially look for any evidence of hypokalemia. Still, postmortem toxicological and histological studies are essential for an accurate identification of the cause of death.

Dust Explosion Quantitative Risk Management for Nontraditional Dusts

The current paper describes an approach for dust explosion quantitative risk management of the following nontraditional particulate fuel systems: (i) nanomaterials having particles with dimensions between 1 and 100 nm, (ii) flocculent (fibrous) materials characterized by a length-to-diameter ratio rather than a particle diameter, and (iii) hybrid mixtures consisting of a combustible dust and a flammable gas (or a combustible dust wetted with a flammable solvent). Experimental results are considered as input to a quantitative risk management framework so as to provide a comprehensive procedure to analyze, assess and control the likelihood and consequences of explosions of nontraditional dusts. Using concepts drawn from previous studies, the framework consists of three main components: (i) a new combined safety management protocol, (ii) use of the CFD (computational fluid dynamics) software DESC (Dust Explosion Simulation Code) and FTA (Fault Tree Analysis) to determine explosion consequences and likelihood, respectively, and (iii) application of the hierarchy of controls (inherent, engineered and procedural safety) to achieve residual risk reduction.

Cone outer segment and Müller microvilli pericellular matrices provide binding domains for interphotoreceptor retinoid-binding protein (IRBP)

The close packing of vertebrate photoreceptors presents a challenge to the exchange of molecules between the outer segments, retinal pigmented epithelium (RPE), and Müller glia. An extracellular hyaluronan scaffold separates these cells while soluble interphotoreceptor matrix (IPM) proteins traffic visual cycle retinoids, fatty acids, and other molecules between them. In the IPM, retinoids and fatty acids are carried by interphotoreceptor retinoid-binding protein (IRBP). The fact that much of the retina's IRBP can be extracted by saline wash has led to the notion that IRBP does not bind to the retina, but freely distributes itself within the subretinal space. In this study, we challenge this idea by asking if there are specialized IPM domains that bind IRBP, perhaps facilitating its ability to target delivery/uptake of its ligands. Xenopus is an ideal animal model to study the role of the IPM in RPE-photoreceptor interactions. Here, we took advantage of the large size of its photoreceptors, ability to detach the retina in light, sustainability of the retina in short term organ culture, and the availability of recombinant full-length Xenopus IRBP and antisera directed against Xenopus IRBP. We compared the distribution of wash resistant native IRBP, and that of IRBP-Alexa 647 binding in Xenopus retina. IRBP and cone opsin were localized using anti-Xenopus IRBP serum, and monoclonal COS-1 respectively. Cone matrix sheath proteoglycans were localized with wheat germ agglutinin (WGA), and diffuse IPM proteoglycans with peanut agglutinin (PNA). Wholemounts and frozen sections were compared by immunofluorescence from retinas detached under Ringer's followed by additional washes, or detached directly under 4% paraformaldehyde without Ringer's wash. Undetached Lowicryl embedded retinas were subjected to IRBP immunogold electron microscopy (EM). Immunogold labeled a diffuse network of filamentous structures, and a separate distinct flocculant material directly coating the outer segments, filling the rod periciliary ridge, and associated with Müller microvilli. By immunofluorescence, Ringer's wash removed most of the diffuse IRBP, but not that coating the outer segments. IRBP-Alexa 647 bound to the cone outer segments and Müller villi region, and comparably less to rod outer segments. Co-incubation with unlabeled IRBP markedly reduced this binding; ovalbumin-Alexa 647 and Alexa 647 dye alone showed no binding. Our data suggest that the pericellular matrix of the cone outer segments and Müller microvilli provide specialized domains that facilitate IRBP's functions.

Analysis of serum and cerebrospinal fluid in clinically normal adult miniature donkeys

AIM: To establish reference intervals for serum and cerebrospinal fluid (CSF) parameters in clinically healthy adult miniature donkeys. METHODS: Experiments were conducted on 10 female and 10 male clinically normal adult miniature donkeys, randomly selected from five herds. Lumbosacral CSF collection was performed with the sedated donkey in the standing position. Cell analysis was performed immediately after the samples were collected. Blood samples were obtained from the jugular vein immediately after CSF sample collection. Sodium, potassium, glucose, urea nitrogen, total protein, calcium, chloride, phosphorous and magnesium concentrations were measured in CSF and serum samples. A paired t-test was used to compare mean values between female and male donkeys. RESULTS: The CSF was uniformly clear, colourless and free from flocculent material, with a specific gravity of 1.002. The range of total nucleated cell counts was 2–4 cells/μL. The differential white cell count comprised only small lymphocytes. No erythrocytes or polymorphonuclear cells were observed on cytological examination. Reference values were obtained for biochemical analysis of serum and CSF. Gender had no effect on any variables measured in serum or CSF (p>0.05). CONCLUSION AND CLINICAL RELEVANCE: CSF analysis can provide important information in addition to that gained by clinical examination. CSF analysis has not previously been performed in miniature donkeys; this is the first report on the subject. In the present study, reference intervals for total nucleated cell count, total protein, glucose, urea nitrogen, sodium, potassium, chloride, calcium, phosphorous and magnesium concentrations of serum and CSF were determined for male and female miniature donkeys.

Remediation of Heavy Metal Ions of Cadmium, Lead And Mercury From Its Salts Solution, By Precipitating Out Using Biological Fluid Indian Buffalo’s (Bubalusarnee) Milk Subsequent Analysis of Filtrate By Icp-Aes And X Ray Fluorescence of White Flocculent Precipitate Containing Milk Protein and of Filtrate Solution.

Boiled buffalos milk has been used to precipitate out metal ions of Cd,Pb and Hg from its salt solution of nitrates. The white flocculent containing metal ion and milk protein has been filtrated out the white flocculent after several wash was dried tested by Xray Fluroescence for the presence of these metals in the white flocculent. Xray Fluroescence results confirm the presence of these metal in the white flocculent .ICP-AES analysis for the filtrate solution have also been carried out for quantitative measurement of metal ion in the filtrate solutions ICP-AES results show for cadmium ion from conc of 450ppm in control solutions it becomes 95ppm,in case of Pb ion Control conc of 960ppm it becomes 15ppm and for Mercury control conc of 21660ppm it becomes 500ppm after addition of 20ml aliquot of boiled buffalo milk in 100ml of metal ions solution. The dilution effect taken in to account reduction in the metal ions conc from control solutions actually goes to the white Flocculent Milk protein by replacing Ca from the original Milk protein by toxic heavy metal ions a theory has been proposed based on the std reduction potential chart of metal ions. Thus biological fluid buffalos milk which is available in plenty in the world can be used for replacing synthetic reagents thus checking the environmental pollution thus can emerge as one of the best Green chemistry reagents and it may help in the metal processing industries of these toxic metals to ease pollution. I. INTRODUCTION. Last 300 years with rapid growth of science and technology human race thought they have able to manipulate many things in the nature and make life better, however soon it has been realized the anthropogenic activities(1) leads different kind of environmental pollution it may be air pollution, water pollution , earth pollution or space pollution. Now we cannot go back to primitive stage nor we can advance in the same direction , so a middle path approach which can keep essence of modern science at the same time use natural substances which is easily available around us for utilization to protect the nature is being envisaged allover the world like for example currently the emergence of green chemistry concept (2) where the processes are being made more natural instead of final product recycling has been given top most thought. One such approach for remediation of toxic heavy metal ions Cd, Pb and Hg from its salt solution of nitrites using easily available Indian buffalos milk has been tried. In the last article of the author in the same journal cows urine have been utilized to precipitate out these toxic heavy metals has been reported(3). The use of biological fluids such as cows urine or buffalos milk for remediation of toxic heavy metals has never been reported in internet search or else where , thus it opens new vistas for environmental pollution control. The reason of trying buffalos milk is not throwing stone in the dark which may hit the target but with proper scientific basis and understanding. Milk contains protein and Buffalos milk contain maximum protein as compared to cows , Goat and Camel milk . The protein has got natural affinities for these toxic heavy metals(4) especially because of sulfydryl groups - SH like in protein cysteine which is found in the milk(5) II. Experimental. Indian Buffalo (Bubalus ar nne) milk have been procured from local Buffalo shed. Milk was boiled to make it condense till the color changes to slightly reddish hue. The nitrate salts of Cadmium . Lead and Mercury was procured from local sd fine chemicals,Mumbai, India. The solutions of these heavy metal salts were made in nano pure water. The conc.of heavy metal ions in the solutions were of range 460ppm to 21000ppm. for Cd,Pb and Hg. In 100ml of the aliquot of these solutions 20ml of boiled buffalo milk were added. The addition of milk leads to precipitation of white flocculent protein material just like milk splitting phenomena but in this case white flocculent sinks at the bottom within 5-10 minutes. of addition of milk. The settling of white flocculent protein material was separated from the rest of the solution by filtrating out. The white flocculent

Microbiological characterization of post-eruption “snowblower” vents at Axial Seamount, Juan de Fuca Ridge

Microbial processes within the subseafloor can be examined during the ephemeral and uncommonly observed phenomena known as snowblower venting. Snowblowers are characterized by the large quantity of white floc that is expelled from the seafloor following mid-ocean ridge eruptions. During these eruptions, rapidly cooling lava entrains seawater and hydrothermal fluids enriched in geochemical reactants, creating a natural bioreactor that supports a subseafloor microbial “bloom.” Previous studies hypothesized that the eruption-associated floc was made by sulfide-oxidizing bacteria; however, the microbes involved were never identified. Here we present the first molecular analysis combined with microscopy of microbial communities in snowblower vents from samples collected shortly after the 2011 eruption at Axial Seamount, an active volcano on the Juan de Fuca Ridge. We obtained fluid samples and white flocculent material from active snowblower vents as well as orange flocculent material found on top of newly formed lava flows. Both flocculent types revealed diverse cell types and particulates when examined by phase contrast and scanning electron microscopy (SEM). Distinct archaeal and bacterial communities were detected in each sample type through Illumina tag sequencing of 16S rRNA genes and through sequencing of the sulfide oxidation gene, soxB. In fluids and white floc, the dominant bacteria were sulfur-oxidizing Epsilonproteobacteria and the dominant archaea were thermophilic Methanococcales. In contrast, the dominant organisms in the orange floc were Gammaproteobacteria and Thaumarchaeota Marine Group I. In all samples, bacteria greatly outnumbered archaea. The presence of anaerobic methanogens and microaerobic Epsilonproteobacteria in snowblower communities provides evidence that these blooms are seeded by subseafloor microbes, rather than from microbes in bottom seawater. These eruptive events thus provide a unique opportunity to observe subseafloor microbial communities.

Ultrastructural Analysis of in Vitro Adherence and Production of Acid Proteases by Clinical Isolates of <i>Candida parapsilosis</i> Sensu Stricto Following Growth in the Presence of Keratinous Substrates from Human Source

Candida parapsilosis is an increasingly important human pathogen. However, little is known about its potential to cause disease. The aims of the present study were to analyse the production of acid proteinases by clinical isolates of C. parapsilosis in the presence of different keratinous substrates from human sources (stratum corneum, nail and hair) and to verify the capability of yeast cells to adhere and grow as biofilm on these substrates. By scanning electron microscopy, it was observed that all C. parapsilosis sensu stricto isolates adhered to the keratinous substrates. For the isolate recovered from onychomycosis, the cell population attached to stratum corneum and hair keratin consisted mainly of blastoconidia. Differently, on nail keratin, pseudohyphae production was observed. Overall, there was a loose association between yeast cells and keratinous substrates. However, on stratum corneum, flocculent extracellular material was seen evolving cells from the onychomycosis isolate by forming a biofilm-like structure. The isolates recovered from onychomycosis and cutaneous lesion produced higher amount of acid proteinases in medium supplemented with nail keratin and stratum corneum keratin, respectively, than that in salt medium (absence of keratin). Furthermore, no differences were observed in the amount of acid proteinases produced by the isolate recovered from tracheal secretion in the media tested (absence and presence of keratin substrates). The information derived from this study will further our understanding of acid proteinase production by C. parapsilosis isolates and provide an insight into pathogenic mechanisms in C. parapsilosis particularly from isolates recovered from superficial mycoses.

Biomarker assessment of spatial and temporal changes in the composition of flocculent material (floc) in the subtropical wetland of the Florida Coastal Everglades

Environmental context Flocculent material (floc) in freshwater and coastal areas of the Florida Everglades plays an important role in food web dynamics and nutrient cycling. Using biomarkers and pigment chemotaxonomy, we determined the organic matter composition of floc from different environments in the Everglades, and found that it is dominated by local biomass inputs and influenced by hydrological regimes. With the on-going restoration of the Florida Everglades, it is important to gain a better understanding of the biogeochemical dynamics of floc, including its sources, transformations and reactivity. Abstract Flocculent material (floc) is an important energy source in wetlands. In the Florida Everglades, floc is present in both freshwater marshes and coastal environments and plays a key role in food webs and nutrient cycling. However, not much is known about its environmental dynamics, in particular its biological sources and bio-reactivity. We analysed floc samples collected from different environments in the Florida Everglades and applied biomarkers and pigment chemotaxonomy to identify spatial and seasonal differences in organic matter sources. An attempt was made to link floc composition with algal and plant productivity. Spatial differences were observed between freshwater marsh and estuarine floc. Freshwater floc receives organic matter inputs from local periphyton mats, as indicated by microbial biomarkers and chlorophyll-a estimates. At the estuarine sites, the floc is dominated by mangrove as well as diatom inputs from the marine end-member. The hydroperiod (duration and depth of inundation) at the freshwater sites influences floc organic matter preservation, where the floc at the short-hydroperiod site is more oxidised likely due to periodic dry-down conditions. Seasonal differences in floc composition were not consistent and the few that were observed are likely linked to the primary productivity of the dominant biomass (periphyton in the freshwater marshes and mangroves in the estuarine zone). Molecular evidence for hydrological transport of floc material from the freshwater marshes to the coastal fringe was also observed. With the on-going restoration of the Florida Everglades, it is important to gain a better understanding of the biogeochemical dynamics of floc, including its sources, transformations and reactivity.

Evidence of lasting impact of the Deepwater Horizon oil spill on a deep Gulf of Mexico coral community

Abstract A coral community 11 km southwest of the site of the Deepwater Horizon blowout at 1,370 m water depth was discovered 3.5 months after the well was capped on 3 November 2010. Gorgonian corals at the site were partially covered by a brown flocculent material (floc) that contained hydrocarbons fingerprinted to the oil spill. Here we quantify the visible changes to the corals at this site during five visits over 17 months by digitizing images of individual branches of each colony and categorizing their condition. Most of the floc visible in November 2010 was absent from the corals by the third visit in March 2011, and there was a decrease in the median proportions of the colonies showing obvious signs of impact after the first visit. During our second visit in 2010, about six weeks after the first, we documented the onset of hydroid colonization (a sign of coral deterioration) on impacted coral branches that increased over the remainder of the study. Hydroid colonization of impacted portions of coral colonies by the last visit in March 2012 correlated positively with the proportion of the colony covered by floc during the first two visits in late 2010. Similarly, apparent recovery of impacted portions of the coral by March 2012 correlated negatively with the proportion of the coral covered with floc in late 2010. A notable feature of the impact was its patchy nature, both within and among colonies, suggesting that the impacting agent was not homogeneously dispersed during initial contact with the corals. While the median level of obvious visible impact decreased over time, the onset of hydroid colonization and the probability of impacts that were not visually obvious suggest that future visits may reveal additional deterioration in the condition of these normally long-lived corals.

Biological Treatment of Landfill Leachate Using Sea Water Microflora Under Aerobic and Anaerobic Conditions

The present study demonstrates an appropriate technique for treatment of landfill leachate. Pretreat ment with alu m and anionic poly electrolyte as coagulant and flocculent materials caused 43% reduction of COD. Sucrose and nutrient broth were used for enrichment of sea water microflora. The pretreated leachate was used for determination of aerobic and anaerobic biological treat ments of sea water enriched microflora. BOD5, COD and TSS reduction were acquired in best samples 90.3%, 95.1% and 44.8% in aerobic and 31.2%, 38.3% and 37.3% in anaerobic conditions, respectively. The metal removal was determined in aerobic and anaerobic treat ments and up to 90% metal removal acquired in some cases.

Unique structures of organelles observed in primary spermatocytes after micro-injection of protein solutions such as immunoglobulin into the lumen of the seminiferous tubules in mice and rats

Unique membranous structures of intracytoplasmic organelle, sting of a stack of a few flat cisternae about 50nm in thickness, were found in mouse and rat spermatocytes after micro-injection of immunoglobulin G into the lumina of the seminiferous tubules. Other proteins such as BSA and cytochrome c used in this study also induced the structures. In most cases, the stacks of cisternae were rolled up like cigars or cylinders. The structures varied in length and diameter, the largest one observed in this study being 10.7μm in length. The structures did not appear when the testes were fixed just after micro-injection and were formed transiently: they were observed in the spermatocytes fixed between 1 and 4h after injection. Cytochrome c, micro-injected as an inter-cellular tracer, was visualised by a diaminobenzidine reaction. As the reaction product was not contained in the cisternae of the unique structures, the lumen of the cisternae of the organelles was not continuous with the inter-cellular space. A flocculent material of low density was observed in the cisternae of the organelle. Similar material was observed in the lumina of solitary cisternae of the rough endoplasmic reticulum in the spermatocytes, suggesting that the structures derived from endoplasmic reticulum.

Arsenic in hot springs of Bahía Concepción, Baja California Peninsula, México

High arsenic concentrations (0.15 to 0.78mg/L) were measured in water discharged from hydrothermal vents at Bahía Concepción, Baja California Sur. Additionally, concentrations above the average for the continental crust (1.8mg/kg) were determined in rocks and marine sediments. Rock samples collected around intertidal and submarine hydrothermal discharges are encrusted by deposits of opaline silica, barite, calcite, and Mn oxides, and in subordinate amounts of pyrite and ferrihydrite. Sequential extraction showed that arsenic is adsorbed mainly on amorphous and crystalline iron-oxides, and in lower concentrations, to the easily extractable phase. When hydrothermal fluids mix with oxidizing and alkaline seawater (pH about 8.3), arsenic in H3AsO3 is oxidized to form H2AsO4− or possibly a deprotoned form such as HAsO42−. In addition reduced iron from the hydrothermal fluid is oxidized to ferric ion and forms non-crystalline ferric hydroxide Fe (OH)3, which is able to adsorb arsenic. X-ray elemental maps of the surface of the rock samples located near the submarine discharges, show evidence that arsenate is adsorbed onto calcite surface. Iron-oxyhydroxides with adsorbed As could be present on the seafloor forming deposits of flocculent material, which can be incorporated into the tissue of some marine organisms (e.g. holothurians) that feed in the vicinity of the hydrothermal manifestations. Oxidation and adsorption processes control transport and mobilization of arsenic in Bahía Concepción hydrothermal fluids.

In vitro antifungal activity of the flavonoid baicalein against Candida species

The aim of the present study was to evaluate the in vitro activity of baicalein, the flavone constituent of Scutellaria baicalensis, and synergism of the combination of baicalein and fluconazole against Candida albicans, Candida tropicalis and Candida parapsilosis. The MIC(50) (lowest concentration at which there was 50 % inhibition of growth) of baicalein alone against six Candida strains ranged from 13 to 104 µg ml(-1). For the three species tested, exposure to baicalein at the MIC(50) concentrations obtained for each strain resulted in a high loss of viability. The fluconazole plus baicalein combination markedly reduced the MICs of both drugs for all three strains analysed. In addition, a synergistic effect between baicalein and fluconazole was observed for C. parapsilosis in terms of MIC(50) (fractional inhibitory concentration index = 0.207). Scanning electron microscopy analysis revealed that yeast cells exposed to baicalein at MIC(50) produced a profusely flocculent extracellular material, resembling a biofilm-like structure. In conclusion, these results showed the antifungal capability of baicalein against Candida species and highlight a promising role of baicalein when used in combination with fluconazole against Candida infections.

Unusual adhesive production system in the barnacle Lepas anatifera: An ultrastructural and histochemical investigation

Adhesives that are naturally produced by marine organisms are potential sources of inspiration in the search for medical adhesives. Investigations of barnacle adhesives are at an early stage but it is becoming obvious that barnacles utilize a unique adhesive system compared to other marine organisms. The current study examined the fine structure and chemistry of the glandular system that produces the adhesive of the barnacle Lepas anatifera. All components for the glue originated from large single-cell glands (70-180 μm). Staining (including immunostaining) showed that L-3,4-dihydroxyphenylalanine and phosphoserine were not present in the glue producing tissues, demonstrating that the molecular adhesion of barnacles differs from all other permanently gluing marine animals studied to date. The glandular tissue and adhesive secretion primarily consisted of slightly acidic proteins but also included some carbohydrate. Adhesive proteins were stored in cytoplasmic granules adjacent to an intracellular drainage canal (ICC); observations implicated both merocrine and apocrine mechanisms in the transport of the secretion from the cell cytoplasm to the ICC. Inside the ICC, the secretion was no longer contained within granules but was a flocculent material which became "clumped" as it traveled through the canal network. Hemocytes were not seen within the adhesive "apparatus" (comprising of the glue producing cells and drainage canals), nor was there any structural mechanism by which additions such as hemocytes could be made to the secretion. The unicellular adhesive gland in barnacles is distinct from multicellular adhesive systems observed in marine animals such as mussels and tubeworms. Because the various components are not physically separated in the apparatus, the barnacle adhesive system appears to utilize completely different and unknown mechanisms for maintaining the liquid state of the glue within the body, as well as unidentified mechanisms for the conversion of extruded glue into hard cement.

Histological study of experimental hyperprolactinemia on the prostate lateral lobe of adult albino rats

Introduction Prolactin, besides androgens, plays an important role in the regulation of prostatic function. Aim of the study This study aimed to demonstrate the influence of experimental hyperprolactinemia on the structure of the prostate lateral lobe in adult albino rats. Materials and methods Twenty healthy adult albino rats were equally divided into two groups: a control group and an experimental group. Rats of the experimental group were intraperitoneally injected with metoclopramide at a dose of 2.2mg/kg for 14 successive days to induce hyperprolactinemia. The control group was injected with saline in the same manner. Hormonal assays for serum prolactin and testosterone levels were carried out. Prostate was extirpated and the lateral lobes were processed for examination by light and electron microscopy. Epithelial height of the prostatic lateral lobes acini was determined morphometrically and analyzed statistically. Results In the experimental hyperprolactinemic group, numerous prostatic acini were lined by multiple layers of epithelial cells (hyperplasia). Acinar epithelium had different ultrastructural features. Some acini had pleomorphic nuclei, cytoplasmic vacuoles, and residual bodies. Others were packed with extensive cisternae of rough endoplasmic reticulum and secretory vesicles. Others had few secretory vesicles and the majority of them had centrally located flocculent material surrounded by electron-lucent zones. Some epithelial cells contained lipofuscin pigments. The prostatic epithelial lining was infiltrated by inflammatory cells. Stromal thickening was found in between some acini that was surrounded by prominent smooth muscle cells and many connective tissue cells. Hormonal assays showed increased serum prolactin and decreased testosterone as compared with the control group. The estimated and analyzed epithelial height of the prostatic acini showed a highly significant increase compared with the control group. Conclusion Hyperprolactinemia altered the morphology of epithelium and stroma of the prostate lateral lobe. It played a significant role in inducing a prostatic hyperplasia and an inflammatory response that triggered the abnormal growth of prostate.

Gulf spill two years out

Summary Two years on, the national spotlight seems to have turned away from the Gulf oil spill, but a massive assessment of the environmental impacts is quietly under way. As Cyrus Martin reports, several recent observations, and a study of deepwater coral communities, suggest we may not be out of the woods yet.

Impact of the Deepwater Horizon oil spill on a deep-water coral community in the Gulf of Mexico.

To assess the potential impact of the Deepwater Horizon oil spill on offshore ecosystems, 11 sites hosting deep-water coral communities were examined 3 to 4 mo after the well was capped. Healthy coral communities were observed at all sites >20 km from the Macondo well, including seven sites previously visited in September 2009, where the corals and communities appeared unchanged. However, at one site 11 km southwest of the Macondo well, coral colonies presented widespread signs of stress, including varying degrees of tissue loss, sclerite enlargement, excess mucous production, bleached commensal ophiuroids, and covering by brown flocculent material (floc). On the basis of these criteria the level of impact to individual colonies was ranked from 0 (least impact) to 4 (greatest impact). Of the 43 corals imaged at that site, 46% exhibited evidence of impact on more than half of the colony, whereas nearly a quarter of all of the corals showed impact to >90% of the colony. Additionally, 53% of these corals' ophiuroid associates displayed abnormal color and/or attachment posture. Analysis of hopanoid petroleum biomarkers isolated from the floc provides strong evidence that this material contained oil from the Macondo well. The presence of recently damaged and deceased corals beneath the path of a previously documented plume emanating from the Macondo well provides compelling evidence that the oil impacted deep-water ecosystems. Our findings underscore the unprecedented nature of the spill in terms of its magnitude, release at depth, and impact to deep-water ecosystems.