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At least 253 records · Page 14Linked to original sources

Characterization and viral safety validation study of a pasteurized therapeutic concentrate of antithrombin III obtained through affinity chromatography.

BACKGROUND AND OBJECTIVE: Antithrombin III (ATIII) concentrates are employed as therapy for congenital or acquired deficiencies. These concentrates are obtained from Cohn's fraction IV1. To improve yields, purity and safety, our group developed a procedure to obtain a pasteurized ATIII concentrate from the supernatant of Cohn's fraction II + III including a highly efficient heparin affinity chromatography purification and pasteurization as a viral inactivation step. DESIGN AND METHODS: Three steps of the manufacturing procedure (Cohn's fraction II + III precipitation, affinity chromatography and pasteurization) were selected to examine their efficacy in inactivating and/or removing the selected viruses. RESULTS: The industrial batches show a purity higher than 99% with approximately 95% native heparin binding ATIII. Only albumin and IgG could be detected at trace levels (0.07% and 0.16% of the total protein present, respectively). The specific activity of the product was approximately 6.65 IU/mg protein. Five viruses were spiked into the manufacturing starting materials and samples were collected at various points to determine the infection level of virus. The study showed a reduction factor (log 10) > or = 11.7 for HIV-1; > or = 8.1 for bovine herpes virus (analyzed as a model for herpes and hepatitis B viruses); > or = 8.1 for bovine diarrhea virus (model for hepatitis C and G) and > or = 6.0 for encephalomyocarditis virus (model for hepatitis A and other non-enveloped viruses). INTERPRETATION AND CONCLUSIONS: No biochemical alterations of the ATIII were detected in the final product. A high viral elimination capacity of the production process was demonstrated. So far, more than 32 million units of ATIII have been transfused in the form of this therapeutic concentrate without any detected seroconversion.

Antithrombin III↗

Detection of Listeria in raw and pasteurized milk.

One hundred raw milk samples from different regions of Anatolia and 20 pasteurized milk samples from three different manufacturers in Ankara were analyzed for the presence of Listeria spp. L. monocytogenes was found in 1% of the raw milk samples and in 5% (1/20) of the pasteurized milk samples. L. innocua and L. seeligeri were found in 8 and 2% of the raw milk samples, respectively. No other species of Listeria was found. The overall incidence of Listeria spp. was 10% in the raw milk samples and 5% in the pasteurized milk samples.

Animals↗

DESTRUCTION OF VARIOUS KINDS OF MYCOBACTERIA IN MILK BY PASTEURIZATION.

Various strains of unclassified mycobacteria, Mycobacterium tuberculosis (including H37Rv strains), M. bovis, M. avium, M. fortuitum, and bacille Calmette-Guerin, were exposed to the temperature and time of pasteurization in skim milk in test tubes. Of the 195 strains tested, there were a few surviving colonies among 6 of 33 skotochromogens, 1 of 26 photochromogens, 10 of 79 nonchromogens, and 1 of 9 rapid growers. Subcultures of the surviving colonies failed to resist the pasteurization tests on subsequent trials.

Animals↗

Ingestion of yogurt containing Lactobacillus acidophilus compared with pasteurized yogurt as prophylaxis for recurrent candidal vaginitis and bacterial vaginosis.

To compare and assess ingestion of yogurt that contained live Lactobacillus acidophilus with pasteurized yogurt as prophylaxis for recurrent bacterial vaginosis (BV) and candidal vaginitis, we designed a crossover trial during which patients were examined monthly for candidal infection and BV while they were receiving either a pasteurized yogurt or a yogurt that contained live L acidophilus. Forty-six patients in 2 groups of 23 were randomly assigned to each of the study groups. At least 28 (61%) participated during the first 4 months of the study. Seven patients completed the entire study protocol. We concluded that daily ingestion of 150 mL of yogurt, enriched with live L acidophilus, was associated with an increased prevalence of colonization of the rectum and vagina by the bacteria, and this ingestion of yogurt may have reduced episodes of BV.

Adult↗

Elution concentration of proteins cut from two-dimensional polyacrylamide gels using Pasteur pipettes.

The present study devised a new procedure for concentrating proteins cut from primary two-dimensional polyacrylamide gels prior to their structural characterization. Gel spots containing a protein were cut from several identical two-dimensional gels and loaded on the top of a high tensile strength stacking gel in a Pasteur pipette. The protein was concentrated electrophoretically into a small volume in the narrow tip of the pipette. The concentrated protein was then blotted from the stacking gel onto a polyvinylidene difluoride membrane, where the protein was subjected to tryptic on-membrane digestion. Utilizing this system, we identified 22 proteins chosen randomly from two-dimensional gels of proteins from rat dermal papilla cells by internal microsequencing. As much as 1.5 mL volume (cut gel spots in protein sample buffer) could be loaded onto the Pasteur pipettes, generally yielding a final on-membrane area of approximately 2 mm2 after elution concentration and electroblotting onto polyvinylidene difluoride membranes. We concluded that this newly devised system is effective and useful for concentrating proteins prior to structural characterization, and that larger volumes than previously recommended can be effectively concentrated, with little or no effect on the final on-membrane area occupied by the concentrated proteins.

Amino Acid Sequence↗

Antioxidant activity of pasteurized and sterilized commercial red orange juices.

Blood orange juice is a typical Italian product whose red color is primarily associated with anthocyanin pigments. Two orange-based products are present on the market: pasteurized pure juice with 40 days of shelf life, and sterilized beverage containing minimum 12% of concentrated fruit juice. The aim of the present paper is to verify the relationships between the antioxidant properties and the anthocyanins content in a sampling of pasteurized and sterilized commercial red orange juices. The anthocyanins composition was determined by HPLC-MS/MS, while the antioxidant activity was evaluated by the Briggs-Rauscher reaction, selected in order to acquire information at acid pH values, by three radical scavenging assays (DMPD, 2-2'-azinobis-(3-ethylenbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), DPPH), and by FRAP assay to monitor the ferric reducing power. Results showed that antioxidant activity, particularly when measured by ABTS method, is positively related to the content of anthocyanins and that the reduction of anthocyanins content, typical of commercial long-shelf life juices, leads to a remarkable loss of antioxidant power.

Anthocyanins↗

The fluorimetric FAST method, a simple tool for the optimization of microwave pasteurization of milk.

The effect of microwave pasteurization of cow's milk on its nutritional quality was examined by the FAST method (Fluorescence of Advanced Maillard products and Soluble Tryptophan). Raw milk samples were submitted to different laboratory scale in batch microwave treatments using a central composite experimental design based on specific power and treatment time. The FAST index and bacterial count were monitored to assess protein denaturation, modification by the Maillard reaction and pasteurization efficiency, respectively. High discrimination between samples indicated that the FAST method is a potent tool for estimating the deterioration of the milk quality during experimental microwave treatment. Thus, the FAST index can be effectively used as the continuous response in experimental designs set up and to maximize information economically. In short, the FAST method allows us to retain the rapidity of experimental design while providing the advantages of convenience and low cost.

Animals↗

Determination of optimum pH and temperature for pasteurization of citrus juices by response surface methodology.

Optimization of microbial death, enzyme inactivation and vitamin C retention during pasteurization of pH-adjusted orange juice is discussed free of equipment-dependent parameters such as the heating lag. The pH-temperature optimum was determined by response surface methodology in the range of 65 degrees C-75 degrees C and pH 2.5-4.0. The results implied that there was no pectinesterase activity below pH 3.5. Leuconostoc mesenteroides had its maximum and minimum thermal resistance at pH 3.5 and pH 2.7, respectively. For an ideal theoretical process requiring four log cycles of microbial reduction the optimum pasteurization conditions were 12 min at 75 degrees C and pH 2.7.

Ascorbic Acid↗

Pasteurization of antihemophilic factor and model virus inactivation studies.

Heating sterilized albumin preparations at 600 degrees C for 10 hours has historically been shown to yield a hepatitis-free, efficacious product. We have evaluated such a pasteurization procedure with AHF preparations. Procoagulant activity and fibrinogen stability were dependent on the amount of sucrose used as a stabilizer. Flash pasteurization at 72 degrees C was evaluated and was found to be detrimental to AHF. Effect of sucrose concentration was shown on the inactivation kinetics of porcine parvovirus. In the absence of other stabilizers, increased sucrose can provide increased thermoresistance to the virus in 2.5% albumin.

Albumins↗

Pharmacokinetics of two pasteurized factor VIII concentrates by different and multicenter assays of factor VIII activity.

We assessed the pharmacokinetic characteristics of a new high-purity pasteurized FVIII concentrate in comparison with an intermediate purity pasteurized concentrate, produced by the same manufacturer. The study was designed as a cross-over single-dose pharmacokinetic investigation in 8 non-bleeding patients with severe hemophilia A. All patients were given 25 IU/kg of each of the two concentrates, with an interval of at least one week between the two administrations. Decay curves were assessed by collecting 10 serial blood samples over 36 hours following the end of infusion. The concentration of Factor VIII in blood samples was determined in triplicate in three different laboratories using each of the following assay methods: a one-stage clotting assay, a two-stage clotting assay, and a two-stage chromogenic-peptide substrate assay. All pharmacokinetic parameters were calculated by model-independent methods. The two products were found to differ significantly both in the clearance, which was on average 13.8% lower for Haemate P, and in the in-vivo recovery, which was 11.7% lower for Factor VIII:C P on the average. In comparison with previous pharmacokinetic data obtained from other heated Factor VIII concentrates, the clearance of Haemate P was found to be significantly slower, while the half-life of both products was longer. No differences were observed in the Vd-area. These findings indicate that the purification procedures to which both products are subjected do not increase the in-vivo rate of plasma disappearance of Factor VIII.

Adolescent↗

Public health implication of refrigerated pasteurized ('sous-vide') foods.

Food that upon pasteurization is stored in hermetically sealed containers at food temperatures not exceeding 3 degrees C could be designated by the generic term Refrigerated Pasteurized Foods of Extended Durability, REPFEDs. If not properly processed or protected against recontamination, or if temperature-abused, REPFEDs may present serious health risks. However, control is readily available. Sound microbial ecology, supported by expert risk assessment, allows the design and introduction of longitudinally integrated manufacture, distribution, handling by outlets and consumers and culinary preparation, which result in the assurance of the wholesomeness of the commodity as eaten. Recent progress, including intrinsic preservation by the incorporation of starter cultures, bacteriocins or particular enzymes, opens vistas for attractive future developments. Once microbiological safety has been built into the REPFED-line, monitoring can be limited to (i) real-time tests particularly applied to the factory environment; and (ii) rapid, simple examination for marker organisms of freshly manufactured products versus those approaching expiration dates. Such audits will allow rapid retrieval of incidental process failure and its rectification. It also serves to substantiate measurements of food temperature and spot checks on intrinsic inhibitory attributes. The application of scientific knowledge and technological expertise should primarily be entrusted to the industry itself, heeding Lord Plumb's strategy of "partnership along the food production chain from farm to fork." It should be supported and validated by Public Health Authorities. At all stages safety communication with the public should be ensured.

Bacteria↗

Comparative trial of administration of half (0.05 mg) and quarter (0.025 mg) dose of intradermal Pasteur BCG on 291 infants from birth to 1 year in French Guyana.

The study concerns 291 newborns and infants aged 0 to 1 year placed randomly in two groups which respectively received 0.025 and 0.05 mg Pasteur BCG by intradermal injection, between 1 December 1988 and 28 February 1989. This random test aimed to determine if the administration of one quarter dose (0.025 mg) of intradermal BCG conferred immunity comparable to that of one half (0.05 mg) while diminishing the risk of complications, in particular suppurative adenopathy, in infants of ages 0-1 year. Statistical analysis of the results showed that the 0.025 mg dose of intradermal BCG entails an immunoresponse as satisfactory as that entailed by the 0.05 mg dose, while the rate of suppurative adenitis is significantly higher in the group that received the 0.05 mg dose. It is therefore well justified to recommend a dose of 0.025 mg of intradermal Pasteur BCG for infants aged 1 year and less.

BCG Vaccine↗

Irradiation as a cold pasteurization process of food.

A number of emerging pathogenic microorganisms and parasites in food, the wide publicity of outbreaks of foodborne diseases and the increasing number of immuno-compromised population have resulted in a need to develop proper strategies and technologies to protect health of consumers. Regulations in most countries which are promulgated to ensure safety of foods, are not properly enforced to protect consumers' health especially with regard to food of animal origin. While regulations are in place and properly enforced for liquid foods such as milk or fruit juices, more solid foods especially those of animal origin, e.g. poultry, meat and seafood, which are often contaminated by pathogenic microorganisms and parasites, are not similarly regulated. The number of incidences of foodborne diseases can the subsequent economic impact to the society can be enormous. Recently, an increasing number of national and international organizations have recognised the use of irradiation as a method to ensure hygienic quality of more solid food of animal origin in the same manner as thermal pasteurization does for liquid foods. The effectiveness of irradiation as a cold pasteurization method to control foodborne disease caused by pathogenic microorganisms and parasites, especially in food to be consumed raw or partially processed, is established. Its role in overcoming trade barriers of food of animal origin based on the principle of the Agreement on the Application of Sanitary and Phytosanitary Measures, adopted during the GATT Uruguay Round will be discussed.

Animals↗

Drip breast milk: it's composition, collection and pasteurization.

"Drip breast milk" is that milk which spontaneously drips from the contralateral breask during the suckling of an infant. Biochemically and immunologically, pooled drip milk resembled pooled mature expressed breast milk, although it has a lower fat concentration. About 15% of lactating women are capable of producing drip milk; volumes produced are up to 188 ml/donor/day. A milk bank is described which processes 1400 liters of drip milk/yr. Heat treatment of this milk with a semi-automated holder pasteurizer caused a 21% reduction in IgA concentration and a 36% reduction in lysozyme activity, as well as a decrease in the ability of the milk to inhibit the growth of E. coli. In comparison with boiling, pasteurization was as effective in reducing total bacterial content provided the milk initially contained fewer than 10(6) bacteria/ml.

Electrolytes↗

Survival of Helicobacter pylori in artificially contaminated ultrahigh temperature and pasteurized milk.

Helicobacter pylori (H. pylori) is a very important bacterial pathogen of humans which may cause gastrointestinal illnesses ranging from gastric and duodenal ulcers to neoplastic diseases such as MALToma and gastric cancer. Transmission via contaminated food is still uncertain but several authors believe this can realistically occur and milk may act as a vehicle of infection. This paper reports the results of H. pylori survival trials in pasteurized and ultrahigh temperature (UHT) milks artificially contaminated and aerobically stored at 4 degrees C. The results obtained showed that the four strains used in this study (H. pylori nat 18-19-20 and H. pylori ATCC 43504), had a progressive reduction in bacterial load with a median survival of 9 days in pasteurized milk and 12 days in UHT milk, with approximate average of initial inoculum of 10(5) and 10(6)cfu/ml, respectively. These findings are very important to clarify the route of transmission of H. pylori to humans via food and for implementation of a correct risk analysis for food safety purposes.

Animals↗

Presence of aflatoxin M1 in pasteurized milk from Morocco.

Fifty four samples of pasteurized milk produced by five different dairies from Morocco were surveyed for the presence of aflatoxin M1 (AFM1) using immunoaffinity columns and liquid chromatography coupled to fluorescence detection. Confirmation of AFM1 identity in positive samples was based on the formation of AFM1 hemi-acetal derivative (AFM2a) after derivatization with trifluoracetic acid. Analytical results showed that 88.8% of the samples were contaminated with AFM1; 7.4% being above the maximum level of 0.05 microg/L set by the Moroccan and European regulations for AFM1 in liquid milk. The incidence of AFM1 in milk from these dairies was 100, 92.3, 90, 83.3 and 77.7% respectively, with AFM1 levels ranging from 0.001 to 0.117 microg/L and a mean value of 0.0186 microg/L. Based on the results presented in this study, the estimated daily intake of AFM1 was 3.26 ng/person/day. In this work, data on the natural occurrence of AFM1 in pasteurized milk produced in Morocco is presented for the first time.

Aflatoxin M1↗

Molecular identification of Yersinia enterocolitica isolated from pasteurized whole milk using DNA microarray chip hybridization.

A DNA microarray chip of four virulence genes and 16S ribosomal DNA gene conserved region among all Gram negative species, including Yersinia, as a positive control was developed and evaluated using 22 Yersinia enterocolitica isolates. Eight different oligonucleotide probes (oligoprobes) with an average size of 22 bp, complementary to the unique sequences of each gene, were designed and immobilized on the surface of chemically modified slides. Multiplex PCR was used to simultaneously amplify DNA target regions of all five genes, and single stranded DNA (ssDNA) samples for microarray analysis were prepared by using a primer extension of amplicons in the presence of one primer of all genes. The presence of genes in Y. enterocolitica was established by hybridization of the fluorescently labeled ssDNA representing different samples of the microarray gene-specific oligoprobes and confirmed by PCR. Results of the study showed specificity of genotyping Y. enterocolitica using multiple microarray-based assays. Final validation of the chip's ability to identify Y. enterocolitica genes from adulterated pasteurized whole milk was confirmed and successful. The limit of chip detection of virulence genes in pasteurized whole milk was found to be 1000 CFU per hybridization.

Animals↗