Kinetics and equilibrium adsorption study of selenium oxyanions onto Al/Si and Fe/Si coprecipitates.

Inappropriate treatments for the effluents from semiconductor plants might cause the releases and wide distributions of selenium (Se) into the ecosystems. In this study, Al/Si and Fe/Si coprecipitates were selected as model adsorbents as they often formed during the wastewater coagulation process, and the removal efficiency of selenite (SeO3) and selenate (SeO4) onto the coprecipitates were systematically examined. The removal efficiency of SeO3 and SeO4 was highly related to surface properties of Al/Si and Fe/Si coprecipitates. The surface-attached Al shell of Al/Si coprecipitates shielded a portion of negative charges from the core SiO2, resulting in a higher point of zero charge than that of Fe/Si coprecipitates. Thus, adsorption of SeO3/SeO4 was favorable on the Al/Si coprecipitates. Adsorptions of both SeO3 and SeO4 on Al/Si coprecipitates were exothermic reactions. On Fe/Si coprecipitates, while SeO3 adsorption also showed the exothermic behavior, SeO4 adsorption occurred as an endothermic reaction. The kinetic adsorption data of SeO3/SeO4 on Al/Si and Fe/Si coprecipitates were described well by the pseudo-second-order kinetic model. SeO4 and SeO3 adsorption on Fe/Si or Al/Si were greatly inhibited by the strong PO4 ligand, whereas the weak ligand such as SO4 only significantly affected SeO4 adsorption. The weakest complex between SeO4 and Al was implied by the essentially SeO4 desorption as SeO4/PO4 molar ratios decreased from 0.5 to 0.2. These results were further confirmed by the less SeO4 desorption (41%) from Fe/Si coprecipitates than that from Al/Si coprecipitates (78%) while PO4 was added sequentially.

A comparison of the compositional differences between humic fractions isolated by the IHSS and exhaustive extraction procedures.

Humic substances (HSs), consisting, on the basis of solubilities in aqueous acid and basic media, of humic acids (HAs), fulvic acids (FAs), and humin (Hu), are the major components of soil organic matter (SOM). Most studies of soil/natural organic matter (SOM/NOM) have been carried out on extracts of soils in dilute sodium hydroxide solutions, the solvent used to extract the Standards of the International Humic Substances Society (IHSS). However, Hu, the major component in the classical definition of HSs, is insoluble in aqueous base and is not isolated by the traditional IHSS method. Recently, a sequential exhaustive extraction (SEE) process has been shown to be capable of isolating and separating the major components of the classically defined HSs from the soils of the temperate and tropical regions. The SEE system was used in the present study to isolate the HA/FA and Hu fractions from a subtropical volcanic Taiwanese soil. Chemical and compositional properties of these extracts were then compared with similarly obtained isolates from soils from the different climatic regions. Increases in the aliphatic relative to aromatic carbon contents were observed for both the HA and FA fractions when the pH values of the extraction media were increased. HAs and FAs isolated using the SEE method have spectroscopic profiles similar to those from the IHSS isolate; however, the cumulative extraction efficiency (%) of the SEE method (65 %) for the volcanic soil was much higher than for the traditional IHSS method (33 %). When the residual volcanic soil, following extractions once, three, and eight times with 0.1 M NaOH were then extracted with dimethyl sulphoxide (DMSO) plus concentrated sulphuric acid (the final solvent in the SEE sequence) it was seen that the content of crystalline polymethylene hydrocarbon (33 ppm (13)C-NMR resonance in the Hu (or DMSO/acid)) extract increased relative to the amorphous methylene (30 ppm). That highlights the difficulty in dissolving the more highly ordered hydrocarbon structures that would be expected to have closer associations with the mineral colloids. Although the SEE procedure isolated all of the HAs and FAs from the Yangmingshan soil, extractability of the Hu from the volcanic soil in the DMSO/acid solvent was low (21 %), and contrasted with the much higher yields from temperate and tropical regions. The decreased Hu extraction may arise from its associations with the extensive iron and aluminium hydroxide mineral colloids in the soil. The Hu from this sub-tropical soil was different from the Hus isolated from other soil types, indicating the need to isolate and characterise these recalcitrant organic material in order to understand the organic carbon components in soils in greater detail. Such results would indicate that more attention should be given to mineral colloids in soils, and to the organo/mineral associations that will have an important role in the stabilities of OM in the soil environment.

Characterization of protein-loaded poly(epsilon-caprolactone) microparticles based on a factorial design.

This study was designed to systematically investigate the characteristics of bovine serum albumin (BSA) loaded poly(epsilon-caprolactine) (PCL) microparticles based on a 2(4) factorial experiment. The influences of polyvinyl pyrrolidone (PVP) concentration, BSA/PCL ratio, w/o/o/o ratio, and PEG/PCL ratio on the surface morphology, particle size, as well as the yield of microparticles, encapsulation efficiency of BSA, and in vitro release properties were evaluated. The microparticles were prepared by the w/o/o/o solvent evaporation method. The structure of BSA retained its integrity using this technique. The mean particle sizes of BSA-loded microparticles were in the range of 20-50 microm, and a highly porous morphology existed in these microparticles, irrespective of the formulations. The production yields of microparticles were in the range of 52.1-89.0%, and the encapsulation efficiencies were in the range of 13.8-68.3%. The burst release of BSA was in the range of 6.9-69.0%. The volume ration of the multi-phases significantly affected the encapsulation efficiency of BSA in PCL microparticles, and the initial amount of BSA encapsulated by PCL in terms of BSA/PCL ratio significantly affected the amount of BSA released at the end of 14 days (p < 0.05).

Electrocardiographic and echocardiographic features that distinguish anomalous origin of the left coronary artery from pulmonary artery from idiopathic dilated cardiomyopathy.

Many authors have reported noninvasive means of diagnosing anomalous left coronary artery from pulmonary artery (ALCAPA) and differentiating ALCAPA from idiopathic dilated cardiomyopathy (DCM). Systematic evaluation using these noninvasive diagnostic modalities is not available. To distinguish between ALCAPA and DCM using a systematic approach, we examined 23 patients with ALCAPA (age 1 month to 23 years, median 7 months) and 23 patients with DCM (age 5 days to 16 years, median 6.6 months). Standard 12-lead electrocardiograms (ECG) and 2-dimensional (2-D) and color Doppler echocardiograms were performed. A logistic regression model was applied using ALCAPA diagnosis as the dependent variable and ECG and echocardiographic findings as independent variables. A scoring system was created to establish the ALCAPA diagnosis based on results from the logistic regression. On the logistic regression, the ECG feature of QT pattern in aVL (Q wave > or = 3 mm deep with an inverted T wave) and echocardiographic features of right coronary artery diameter to aortic annulus ratio > or = 0.14, increased papillary muscle echogenicity, and Doppler color flow of LCA from aorta or pulmonary artery were the most significant differentiating features between the ALCAPA and DCM groups. A scoring system was developed using the previous five variables and assigning a score of 1 to each variable (-1 to Doppler color flow of LCA from aorta). The scoring system had sensitivity of 100% and specificity of 91% for ALCAPA diagnosis. Compared with previous reported diagnostic features in differentiating ALCAPA and DCM, the scoring system had a much higher specificity and positive predictive value. In conclusion, we selected the most useful ECG and echocardiographic features to differentiate between ALCAPA and DCM and created a scoring system to aid clinical diagnosis. This scoring system may be useful in evaluating children with acute congestive heart failure.

Prevention of adriamycin-induced full-thickness skin loss using hyaluronidase infiltration.

Full-thickness skin ulceration after extravasation of the commonly used vesicant chemotherapeutic agent doxorubicin hydrochloride (Adriamycin) is a significant source of morbidity in cancer patients. Controversy exists regarding the appropriate management of this extravasation injury. Current therapy includes local hypothermia, local clysis with hyaluronidase, and surgical excision of the involved tissue. Experimental data supporting local clysis with hyaluronidase are limited despite its current use clinically. The purpose of this study was to determine the efficacy of local infiltration with heparin sodium, hyaluronidase, and saline in the prevention of extravasation ulcers in a rat model. One hundred fifty male Sprague-Dawley rats (Upjohn, Milan, Italy) weighing 240 to 260 g, anesthetized with sodium pentobarbital, were used in this study. One hundred thirty rats received a 0.3-ml subcutaneous flank injection of doxorubicin (1.5 mg/ml) followed 15 minutes later by local infiltration with saline (n = 10), 25 to 100 units of heparin (n = 30), or 2.5 to 10.0 units of hyaluronidase (n = 90). Control animals received either subcutaneous doxorubicin (n = 10) or subcutaneous saline alone (n = 10). Volumes of the infiltration solution were less than 1 ml in all groups. All animals were sacrificed at 4 weeks; presence and size of ulcers at the injection site were quantified. Statistical analysis was performed using the two-sided Fisher's exact test and Student's t test. Control rats injected with saline alone did not develop ulceration in any case. All rats injected with doxorubicin alone developed ulcers with an average size of 33 mm2. Heparin infiltration decreased ulcer rate by 20 to 40 percent and decreased ulcer size by up to 67 percent. Local infiltration with hyaluronidase decreased ulcer rate by 50 to 60 percent (p < 0.05, two-sided Fisher's exact test) and decreased ulcer size by up to 50 percent ( p < 0.05, Student's t test). In this rat extravasation injury model, local infiltration with saline, heparin, or hyaluronidase decreased ulcer size after doxorubicin extravasation. This effect may be secondary to dilution of the extravasant. Additionally, local infiltration with hyaluronidase decreased ulcer rate by at least 50 percent. The mechanism of this phenomenon presumably relates to the ability of hyaluronidase to temporarily decrease the viscosity of the hyaluronic acid component of ground substance, thus allowing greater diffusion of doxorubicin into the surrounding tissue and therefore decreasing its local concentration.

Proteolytic maturation of protein C upon engineering the mouse mammary gland to express furin.

Endoproteolytic processing of the human protein C (HPC) precursor to its mature form involves cleavage of the propeptide after amino acids Lys-2-Arg-1 and removal of a Lys156-Arg157 dipeptide connecting the light and heavy chains. This processing was inefficient in the mammary gland of transgenic mice and pigs. We hypothesized that the protein processing capacity of specific animal organs may be improved by the coexpression of selected processing enzymes. We tested this by targeting expression of the human proprotein processing enzyme, named paired basic amino acid cleaving enzyme (PACE)/furin, or an enzymatically inactive mutant, PACEM, to the mouse mammary gland. In contrast to mice expressing HPC alone, or to HPC/PACEM bigenic mice, coexpression of PACE with HPC resulted in efficient conversion of the precursor to mature protein, with cleavage at the appropriate sites. These results suggest the involvement of PACE in the processing of HPC in vivo and represent an example of the engineering of animal organs into bioreactors with enhanced protein processing capacity.

A method for the determination of environmental contaminants in living marine mammals using microscale samples of blubber and blood.

As part of a study examining the possible effects of organochlorine compounds on juvenile northern elephant seals (Mirounga angustirostris), blubber and blood samples were taken from animals present on the Año Nuevo (California) rookery, and from animals admitted for rehabilitation at The Marine Mammal Center (Sausalito CA). Blubber samples were collected from immobilized seals. A pre-cleaned 6 mm K-medic biopsy punch was used to extract the blubber from a 1 cm incision near the hip, near the dorsal mid point. Blood samples were taken from the extradural vein; two mL of serum was analyzed for organochlorine compounds. Blubber samples (approximately 0.1g) were ground with Na2SO4 and extracted with 20 mL hexane:methylene chloride (1:1). Sera samples were extracted using commercially available disposable C18 columns. The extracts were separated on a micro-Florisil column, and analyzed by HRGC-ECD. Lipid determination in the serum was obtained by colorimetric analysis with 20 microliters samples. Results from the analysis of replicates and standard reference materials showed good recoveries, precision, and accuracy for both the blubber and blood methods.

Sample cleanup by solid-phase extraction for the ultratrace determination of polychlorinated dibenzo-p-dioxins and dibenzofurans in biological samples.

A sample cleanup method for the isolation of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) by solid-phase extraction is described. A C18 bonded silica cartridge is used for the initial extraction and enrichment of the analytes. Subsequent cleanup is achieved with a dual-cartridge arrangement consisting of a bonded benzenesulfonic acid cartridge in series with a silica cartridge. A Florisil cartridge is employed for the final cleanup step. Sample preparation procedures used for blood plasma and animal tissues are described. The precision and accuracy of the method is validated by determining recoveries of 2,3,7,8-substituted PCDD and PCDF congeners spiked at various levels in blood plasma and in animal tissues. The effectiveness of the cleanup method is shown by the analysis of wild bird eggs which are highly contaminated with a variety of pesticides and polychlorinated biphenyls. The application of this cleanup method to human plasma containing PCDDs/PCDFs at parts-per-quadrillion levels and results of analyses by high-resolution mass spectrometry and low-resolution mass spectrometry are presented. The validity of this method is demonstrated by the comparable results obtained from this method and from other established methods.

Spontaneous activation of circulating granulocytes in patients with acute myocardial and cerebral diseases.

Recent animal studies have suggested that there exists an activated subpopulation of circulating granulocytes which plays an important part in microvascular sequestration and tissue injury during shock and ischemia. In this respect, spontaneous granulocyte activation in form of pseudopod formation, a manifestation of actin polymerization, is a high risk for microvascular entrapment. The present investigation was carried out to determine if there is a significant difference in pseudopod formation in vitro between granulocytes obtained from healthy volunteers without symptoms and patients with acute cardiovascular illnesses. Blood samples from 25 healthy volunteers, 12 patients with acute myocardial infarction (AMI) and 12 patients with acute cerebral infarction (ACI) to determine spontaneous pseudopod formation in granulocytes with a high resolution light microscope over a period of several hours. The results revealed that the mean percentage of cells with pseudopod formation in the control group was below 10% in the first 3 hours, and increased to about 50% at 12 hours. In AMI patients, the level of activation within the first hour was not significantly different from the controls, but it rose rapidly to 90% in 4 to 5 hours. Patients with cerebral infarction, however, showed no significant difference from the control group. When the granulocytes of healthy subjects were incubated in plasma of AMI, the cells were activated similar to AMI granulocytes in their own plasma. When AMI plasma was serially diluted with Ringer's solution, the activation curve fell successively. These results indicate that AMI patients' blood contains plasma factor(s) which can activate granulocytes at a more rapid rate than controls.

Selective inhibition of isoprenylation of 21-26-kDa proteins by the anticarcinogen d-limonene and its metabolites.

Limonene has chemotherapeutic activity against chemically induced rat mammary carcinomas, many of which contain activated ras genes. Given the recent discovery of the post-translational modification of p21ras and other cell growth-associated proteins by intermediates in the mevalonic acid pathway, and the common biochemical origins of limonene and these isoprene products, we investigated the effect of limonene on protein isoprenylation. NIH3T3 and human mammary epithelial cells were incubated with lovastatin and [2-14C]mevalonolactone in the absence and presence of limonene. Labeled proteins were then subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Limonene inhibited isoprenylation of a class of cellular proteins of 21-26 kDa, including p21ras and possibly other small GTP-binding proteins, in a dose-dependent manner in both cell lines. In contrast, limonene did not affect the isoprenylation of several other proteins, including nuclear lamins. Limonene is metabolized extensively in vivo but not in cultured cells. The two major rat serum metabolites of limonene, perillic acid and dihydroperillic acid, were more potent than limonene in the inhibition of isoprenylation. These results demonstrate that limonene selectively inhibits isoprenylation of 21-26-kDa proteins at a point in the mevalonic acid pathway distal to 3-hydroxy-3-methylglutaryl coenzyme A reductase, and they provide a plausible explanation for its chemotherapeutic activity. Inhibition of isoprenylation of proteins such as p21ras and other small GTP-binding proteins would alter their intracellular localization and, hence, disrupt their biological activity.