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At least 631 records · Page 35Linked to original sources
PubMed1982

Human subcutaneous dirofilariasis. 1. Two new cases in Venice. Identification of the causal agent as Dirofilaria repens Raillet and Henry, 1911.

Two human cases of subcutaneous dirofilariasis are described in a 41 year-old woman and in a 14 year-old boy living in Venice Lido. In the first case, the development of a nodule at the left forearm had been preceded by generalized symptoms such as pruriginous urticarioid patches in various regions of the body, transitory swellings and 8% eosinophilia. From the nodule, an adult female of Dirofilaria repens was recovered with embryos visible in the uterus. In the second case, the parasite was localized in the scrotum, where it had caused an extensive oedema with the formation of a nodule having the size of a nut. An immature female specimen of D. repens was found. In both cases, the serological tests (Indirect Haemoagglutination and Bentonite Flocculation) gave significant titres specific for filariasis (1:256 and 1:20 in the first case, 1:128 and 1:5 in the second, respectively). A parasitological survey of blood samples from 145 stray dogs captured in the territory of the Venice municipality revealed the presence of D. repens in 8.3% of cases, D. immitis in 4.8% and Dipetalonema reconditum in 0.7%. This is the first time that the aetiological agent of human subcutaneous dirofilariasis was identified as D. repens in Italy.

Adolescent↗
PubMed1978

Evaluation of serodiagnostic tests for visceral larva migrans.

Four serologic techniques for the diagnosis of visceral larva migrans caused by Toxocara canis, namely indirect hemagglutination (IHA), bentonite flocculation (BF), enzyme-linked immunosorbent assay (ELISA), and double diffusion in agar (Ouchterlony), were evaluated using sera sent to the Center for Disease Control from patients with a presumptive diagnosis of visceral larva migrans (VLM). Patients having 5-6 of the clinical or laboratory criteria for VLM were designated as cases while those with 0-2 criteria served as controls. The sensitivity of the ELISA was 78.3% compared to 18.2%, 25.8% and 65.2% for the IHA, BF, and Ouchterlony, respectively; the sepcificity of all four tests was greater than 92%. The predivtive value of positive test was greater than 85% for all tests except the IHA, while the predictive value of a negative test was greater than 85% only for the ELISA. The results of a ELISA were reproducible in different laboratories. Based on these findings, the ELISA using a larval antigen appears to be the serodiagnostic method of choice for VLM.

Adolescent↗
PubMed2000

Strategies for maintaining the particle size of peptide DNA condensates following freeze-drying.

The particle size of peptide DNA condensates were studied after freeze-drying and rehydration as a function of sugar excipient, concentration, pH, DNA concentration, and peptide condensing agent. In the absence of an excipient, freeze-dried 50 microg/ml AlkCWK(18) (iodoacetic acid alkylated Cys-Typ-Lys(18)) DNA condensates formed large fibrous flocculates on rehydration. Of the sugars tested as lyoprotectants, sucrose proved most effective at preserving particle size during rehydration. The addition of 5 wt/vol% sucrose preserved a mean particle diameter of less than 50 nm during rehydration of AlkCWK(18) DNA condensates prepared at DNA concentrations up to 200 microg/ml; however, higher DNA concentrations led to the formation of insoluble fibrous flocculates. Substitution of polyethylene glycol (PEG)-CWK(18) as a DNA condensing peptide eliminated the need for sucrose, resulting in peptide DNA condensates that retained particle size when rehydrated in water or normal saline at concentrations up to 5 mg/ml. The results suggest that sucrose functions primarily as a bulking agent during freeze-drying that only preserves the particle size of AlkCWK(18) DNA condensates up to a maximum concentration of 200 microg/ml. Alternatively, the steric layer created on the surface of PEG-CWK(18) DNA condensates provides far more efficient lyoprotection, preserving their particle size at a concentration of 5 mg/ml without a bulking agent.

DNA↗
PubMed1985

Effects of humic materials on virus recovery from water.

Humic and fulvic acids were tested for their ability to interfere with virus recovery by microporous filters. Two electropositively charged types of filter (Seitz S and Zeta Plus 60S) were used to concentrate poliovirus in the presence of humic materials. Humic acid inhibited virus adsorption, but even at the highest humic acid concentrations tested (200 mg/liter), 30 to 40% of the virus was recovered by the filters. Fulvic acid, tested with Zeta Plus filters, did not affect virus recovery. For comparison, two electronegatively charged filter types were tested (Cox and Balston). These two types of filter were more sensitive to interference at lower concentrations of humic acid than the more positively charged filters. With Balston filters, at humic acid concentrations above 10 mg/liter, most of the virus was recovered in the filtrate. Fulvic acid, tested with Balston filters, did not interfere with virus recovery. With the electropositively charged filters, the humic materials adsorbed efficiently, even at high input concentrations. Interference with virus adsorption occurred at humic acid concentrations which were below the level of saturation of the filters. In addition, in high-volume experiments, humic acid led to premature blockage of the filters. The efficiency of virus recovery by a second concentration step, organic flocculation of the filter eluate, was tested. For all the filter types tested, this procedure was not affected by the presence of humic or fulvic acid in the input water.

Benzopyrans↗
PubMed2005

Flocculation control study based on fractal theory.

A study on flocculation control based on fractal theory was carried out. Optimization test of chemical coagulant dosage confirmed that the fractal dimension could reflect the flocculation degree and settling characteristics of aggregates and the good correlation with the turbidity of settled effluent. So that the fractal dimension can be used as the major parameter for flocculation system control and achieve self-acting adjustment of chemical coagulant dosage. The fractal dimension flocculation control system was used for further study carried out on the effects of various flocculation parameters, among which are the dependency relationship among aggregates fractal dimension, chemical coagulant dosage, and turbidity of settled effluent under the conditions of variable water quality and quantity. And basic experimental data were obtained for establishing the chemical coagulant dosage control model mainly based on aggregates fractal dimension.

Aluminum Hydroxide↗
PubMed1980

Serologic diagnosis of Toxocara canis infection.

Visceral larval migrans (VLM) caused by Toxocara canis presents a wide spectrum of clinical manifestations with eosinophilia. Although the presence of increased serum IgE and isohemagglutinin titers are useful screening tests, the specific diagnosis rests on identification of larvae in biopsy specimens of tissues or serologic tests for specific antibody to the Toxocara organism. A 2-year-old boy with marked eosinophilia associated with milk respiratory tract illness had negative indirect hemagglutination (IHA) and bentonite flocculation (BF) titers to Toxocara, but serum tested for specific antibodies against Toxocara embryonated egg (TEE) antigens by the Ouchterlony immunodiffusion and enzyme-linked immunosorbent assay (ELISA) technics was strongly positive.

Child, Preschool↗
PubMed1979

Immunoreactivity in pulmonary echinococcosis. A comparative study of immunodiagnostic tests.

A comparison was made of the diagnostic value of five immunological tests-complement fixation (CF), latex agglutination (LA), bentonite flocculation (BF), passive haemagglutination (PHA), and intradermal (ID)-in patients operated on for pulmonary echinococcosis. The sensitivity of all five tests was significantly lower in the patients with pulmonary echinococcosis than in a comparable group with liver echinococcosis. Some 252 patients with miscellaneous nonhydatid diseases and parasitic infections were also tested; nonspecific reactions were highest in the ID and CF tests and lowest in the LA and BF tests. None of the serological tests was significantly more sensitive than the others, although the CF test was somewhat less sensitive and therefore probably has the least diagnostic value in pulmonary echinococcosis. The ID test showed a significantly higher sensitivity than any of the serological tests. The difficulties encountered in the immunodiagnosis of pulmonary hydatid disease are discussed and it is recommended that at least two serological methods (PHA and either LA or BF) and the ID test should be used in each case.

Echinococcosis, Pulmonary↗
PubMed2005

Removal of natural organic matter in a typical south-China source water during enhanced coagulation with IPF-PACl.

Systematic investigation on enhancing removal of natural organic matter (NOM) using inorganic polymer flocculant (IPF), polyaluminum chloride (PACl) and polyacrylamide (PAM) was performed in a typical south-China source water. Enhanced coagulation and applying polymer flocculant-aid were compared through jar tests and pilot tests. Raw water and settled water were characterized and fractionated by resin adsorption. The results show that DOC composes major part of TOC. The DOC distribution keeps relatively stable all around the year with typical high amounts of the hydrophilic matter around 50%. The distribution between HoB, HoA and HoN varies and undergoes fluctuation with the year round. During the summer season, the HoN becomes gradually the major part in hydrophobic parts. PACI with the species being tailor-made shows little pH effect during coagulation. The enhanced coagulation dosage for PACI could be 4.5 mg/L for the typical source water. The highest TOC removal achieved 31%. To be economically, 3 mg/L dose is the optimum dosage. Although hydrophilic fractions of NOM of both treatment strategies are removed about 30%, NOM causing UV254. absorbance were well removed(about 90%). Hydrophobic bases and acids fractions are much more removed under enhanced conditions. The hydrophilic fraction could be better removed using PAM, the polymer coagulant aid.

Acrylic Resins↗
PubMed2002

Prevalence of Cryptosporidium oocysts and giardia cysts in the drinking water supply in Japan.

A one-year monitoring of Cryptosporidium oocysts and Giardia cysts was conducted at a water purification plant. A total of 13 samples of 50 L river source water and 26 samples of 2,000 L-filtered water, treated by coagulation flocculation, sedimentation and rapid filtration, were tested. Prior to conducting a survey of a water purification plant, we developed a method for concentrating Cryptosporidium oocysts from a large volume of raw or filtered water using a hollow fiber ultrafiltration (UF) membrane, and this procedure was adapted to survey a water purification plant. Cryptosporidium oocysts were detected in all of the 13 raw water samples. The geometric mean concentration was 40 oocysts 100 L. Giardia cysts were detected in 12 of 13 raw water samples (92%) and the geometric mean concentration was 17 cysts/100 L. Probability distributions of both Cryptosporidium oocyst and Giardia cyst concentration in raw water were nearly lognormal. In filtered water samples, Cryptosporidium oocysts were detected in 9 of the 26 samples (35%) with the geometric mean concentration of 1.2 oocysts /1,000 L and Giardia cysts in 3 samples (12%) with 0.8 cysts/1,000 L. The estimated log10 removal efficiency of Cryptosporidium oocysts and Giardia cysts by rapid-sand filtration was 2.47 and 2.53, respectively. Empty particles were removed at a higher log10 than intact oocysts and cysts. The efficiency of particle removal in the rapid sand filtration process tends to be reduced under cold-water conditions. Close management is necessary in the winter when the water temperature is low.

Animals↗
PubMed1992

The flocculation of wine yeasts: biochemical and morphological characteristics in Zygosaccharomyces--flocculation in Zygosaccharomyces.

The floc-forming ability of flocculent strains of Zygosaccharomyces bailii and Z. fermentati, isolated from musts, was tested for susceptibility to proteinase and sugar treatments. Z. fermentati was found highly resistant to the proteolytic enzymes tested, whereas Z. baili was only trypsin-resistant. The inhibition of flocculation by sugars distinguished two types: in Z. fermentati flocculation was completely inhibited by mannose, in Z. bailli by various sugars. By SEM observation, the cell surface of Zygosaccharomyces revealed the presence of a column structure, resulting from fusion of vesicles present on the cell surface.

Cell Adhesion↗
PubMed2003

Porosity and interior structure of flocculated activated sludge floc.

This work estimated the porosities of activated sludge flocs, cationic polyelectrolyte flocculated, based on free-settling tests, buoyant weight measurements, and confocal laser scanning microscope (CLSM) tests. The extent of advective flow was estimated based on bubble-tracking test. The former two measurements suggested a close-to-unity porosity, that is, an extremely void floc interior. Meanwhile, the latter two tests recommended a dense floc interior with a porosity less than 64%. A discrepancy exists between the porosities estimated by various tests. A floc model was proposed based on the understanding that a vast amount of bound water in the floc was regarded as void in buoyant weight measurement, but was impermeable for advective flow. The distribution rather than the mean value of the porosity controls the advective flow. There existed no simple correlation between the porosities measured by different tests.

Journal Article↗
PubMedDate not supplied

Study on agglutinating factors from flocculent Saccharomyces cerevisiae strains.

The lectin-like theory suggest that yeast flocculation is mediated by an aggregating lectinic factor. In this study we isolated an agglutinating factor, which corresponds to lectin, from whole cells by treating the flocculent wild-type Saccharomyces cerevisiae NCYC 625 strain and its weakly flocculent mutant [rho degrees ] with EDTA and two non-ionic surfactants (Hecameg and HTAC). The dialysed crude extracts obtained in this way agglutinated erythrocytes and this hemagglutination was specifically inhibited by mannose and mannose derivatives. However, SDS-PAGE profiles showed that the three reagents had different effects on the yeast cells. The non-ionic surfactants appeared to be the most efficient, as their extracts possessed the highest specific agglutinating activity. The products released by the wild-type strain presented a higher specific agglutinating activity than those released by the [rho degrees ] mutant. Purification of the agglutinating factor from extracts of both strains by affinity chromatography revealed two active bands of relative mass of 26 and 47 kDa on SDS-PAGE. Mass spectrometry analysis by MALDI-TOF, identified a 26 kDa band as the triose phosphate isomerase (TPI) whereas a 47 kDa band was identical to enolase. Edman degradation showed that the N-terminal sequences of these proteins were similar to TPI and enolase, respectively. The difference in the flocculation behaviour of the two strains is due to changes in the protein composition of the cell wall and in the protein structure involved in cell-cell recognition.

Agglutinins↗