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At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Comparison of the compact dry TC method with the standard pour plate method (AOAC official method 966.23) for determining aerobic colony counts in food samples: Performance-tested method.

Compact Dry TC qualifies as a rapid method kit for determining aerobic colony counts in foods. The plates are presterilized and contain culture medium and a cold-soluble gelling agent. The medium is rehydrated by inoculating 1 mL diluted sample into the center of the self-diffusible medium and allowing the solution to diffuse by capillary action. The plates can then be incubated and the colonies counted without any additional steps. The Compact Dry TC method was validated with 5 different raw meats. The performance tests were conducted at 35 degrees and 30 degrees C. In all required performance studies, no apparent differences were observed between the Compact Dry TC method and the Standard Pour Plate method (AOAC Official Method 966.23) for the detection level of aerobic microorganisms. For the accuracy claim (n = 60), a correlation factor of r2(35) = 0.9977 (35 degrees C) and r2(30) = 0.9932 (30 degrees C) could be assigned, as stated in the application for "Performance Tested Method." Quality consistency and storage robustness studies, showed no significant variations in plate count results with different production lots or plates of diverse storage age.

Bacteria, Aerobic↗
PubMedDate not supplied

Cutting boards in Salmonella cross-contamination.

Cutting boards are commonly perceived as important fomites in cross-contamination of foods with agents such as Salmonella spp., despite the lack of supporting epidemiological data. A variety of woods and plastics have been used to make work surfaces for cutting. In general, wood is said to dull knives less than plastic, and plastic is seen as less porous than wood. Research to model the hypothetical cross-contamination has been done in a variety of ways and has yielded a variety of results. At least some of the work with knife-scarred plastic indicates that the surface is very difficult to clean and disinfect, although this may vary among the polymers used. High-density polyethylene, which is most used in commercial applications, has been shown to delaminate in response to knife scarring. Wood is intrinsically porous, which allows food juices and bacteria to enter the body of the wood unless a highly hydrophobic residue covers the surface. The moisture is drawn in by capillary action until there is no more free fluid on the surface, at which point immigration ceases. Bacteria in the wood pores are not killed instantly, but neither do they return to the surface. Destructive sampling reveals infectious bacteria for hours, but resurrection of these bacteria via knife edges has not been demonstrated. Small plastic cutting boards can be cleaned in a dishwasher (as can some specially treated wooden boards), but the dishwasher may distribute the bacteria onto other food-contact surfaces. Most small wooden boards (i.e., those with no metal joiners in them) can be sterilized in a microwave oven, but this should be unnecessary if accumulation of food residues is prevented. However, 2 epidemiological studies seem to show that cutting board cleaning habits have little influence on the incidence of sporadic salmonellosis. Further, one of these studies indicated that use of plastic cutting boards in home kitchens is hazardous, whereas use of wooden cutting boards is not.

Animals↗
PubMedDate not supplied

[Surveillance of health status in an agrarian environment: proposal for a method. 1. Epidemiological data].

In order to evaluate the risk of the exposure of the pesticides and N-nitroso compounds in the agricultural environment not only farm-hands have to be considered but also their families. So it is necessary to prepare survey methodologies to examine the state of health of all individuals who are exposed to same kind of risk (pesticides and nitroso compounds), even if in different ways and intensity. We have therefore chosen four farms situated on the same territory which cultivate vegetables. Three, of these farms, made wide use of pesticides and fertilizers, the fourth one was used as a "control farm" because it did not employ any chemicals. For every farm data about the neighbouring territory, the climate, the kind of cultivation, the pesticides and other employed chemicals were collected. Every subject (in all 25) residing in the farm was interviewed with a standard questionnaire about personal data, the duties performed on the farm, the way in which chemicals were used, their medical history as well as the life style. Samples of blood were drawn periodically in different seasons, over a two year period, to determine both nitrosoamine (NA) and the enzymes which reveal hepatic damage: Alkaline phosphatase (ALP), Leucinoaminopeptidase (LAP), Gamma-glutamyltransferase (GGT) and Acetylcholinesterase (Ach). We have observed that: a. the most frequent pathologies concern skin (16% of the people) and liver (12% of the people), which are favourite targets for agricultural chemicals though the serum enzymes did not show any important change; b. 8% of the subjects had acute pesticide poisoning; we therefore observed neither particular precautionary safety measures, nor a particular knowledge of acute and chronic toxic effects depending on the use of pesticides. So we suggest: 1) that the Sanitary Authorities control the state of health not only of the farm-hands but also of their families, if exposed to risk; this can be realized through the strict collaboration of the Occupational Physician and the Family doctor; 2) capillary action of health education regarding agricultural risks; 3) to increase research to find more sensitive and efficient biological indicators in order to evaluate the hazards of agricultural chemicals.

Adult↗
PubMed1985

Role of insects in the transmission of bovine leukosis virus: potential for transmission by stable flies, horn flies, and tabanids.

The ability of stable flies (Stomoxys calcitrans), horn flies (Haematobia irritans), and tabanids (Diptera: Tabanidae) to transmit bovine leukosis virus (BLV) was investigated. Stable flies and horn flies were fed on blood collected from an infected cow, and the flies' mouthparts were immediately removed, placed in RPMI-1640 medium, ground, and inoculated into sheep and calves. Infection of sheep occurred with mouthparts from as few as 25 stable flies or 25 horn flies. However, sheep were not infected when removal of stable fly mouthparts was delayed greater than or equal to 1 hour after blood feeding. Infection of calves occurred after inoculation of mouthparts removed immediately after feeding from as few as 50 stable flies or 100 horn flies. Infected blood, applied by capillary action to the mouthparts (labella) of 15 deer flies (Chrysops sp) and a single horse fly (Tabanus atratus) caused infection in each of 2 sheep. Infection did not occur in 2 calves inoculated daily for 5 days with mouthparts from 50 horn flies collected after feeding on a BLV-infected steer. Four calves receiving bites from 75 stable flies interrupted from feeding on a BLV-positive cow also were not infected. Seronegative cattle held for 1 to 4 months in a screened enclosure with positive cattle in the presence of biting flies were not infected with BLV. The feeding behavior of each insect is discussed to assess their potential as vectors of BLV.

Animals↗
PubMed1985

Enzyme immunochromatography--a quantitative immunoassay requiring no instrumentation.

We describe a novel test-strip immunoassay for quantifying drugs in biological fluids. This enzyme immunochromatographic ("immunograph") method combines many features of the enzyme-channeling homogeneous immunoassay with immunochromatography and capillary migration to provide a non-separation, non-instrumental assay for theophylline in which quantification is based on the spatial distribution of enzyme label rather than on the modulation of enzyme activity. Sample antigen and hapten-enzyme conjugate are combined and moved by capillary action up a paper strip on which specific antibody has been immobilized. After color development, the assay result is evaluated by measuring the height of the colored zone on the test strip. Quantification is not a function of enzyme activity, so the method is relatively insensitive to sample matrix effects, enzyme instability, temperature, and incubation timing. Either whole blood or plasma can be used as sample. Results correlate well with those by established instrumental methods. The simple, rapid (15 min), two-incubation protocol is well suited for on-site testing in non-laboratory environments.

Animals↗
PubMed1984

[The determination of the Enslin number].

An apparatus after Ezersky was used for the determination of the Enslin number, thereby some error possibilities mentioned in the literature were investigated and compared with the method after the 2. AB-DDR. The dependence of the Enslin number on the height of the powder bed was proofed also at little layer thickness of some substances. The error possibilities are: tending of the powder bed by burning of the lower wet part, occurring of air bubbles below the powder bed and also the capillary action directed against the incorporation at the tip of a completely filled graduated pipet. The apparatus after the 2. AB-DDR as the apparatus after Ezersky, especially with graduated pipet without tip, produced measuring values with little deviation. The latter apparatus allowes a more rational using.

Absorption↗
PubMed1981

Schirmer's test of lacrimation.

Schirmer's test is a simple, semiquantitative test of tear production. It is based on the physical tendency of a fluid to travel along a strip of porous material by capillary action due to surface tension. Sterile strips, standardized and prepackaged, are available from local scientific supply houses. The low cost and simplicity of this test make it useful in confirming the diagnosis of diseases involving decreased lacrimal secretion.

Humans↗
PubMed1994

An evaluation of the HemoCue for measuring haemoglobin in field studies in Jamaica.

The HemoCue system utilizes the principle of oxidation of haemoglobin to hemiglobin by sodium nitrite and the subsequent conversion of hemiglobin to hemiglobinazide by sodium azide. The reagents for these reactions are contained within a small disposable microcuvette of approximately 10 microliters in volume. A venous or capillary sample is introduced into the microcuvette by capillary action and, after reaction with the reagents, the absorbance is read in the HemoCue photometer at 565 and 880 nm. The haemoglobin concentration is then displayed as a digital reading, in either g/dl or mmol/l in 15-45 seconds. We compared haemoglobin values obtained by the HemoCue system with those from the Coulter Counter S-Plus IV in 366 pregnant women in urban Jamaica, and found a highly significant correlation (r = 0.78, P < 0.01). However, because of the convenience and ease of use of this instrument and considering the relatively high cost, we recommend it for use only as a research tool in field studies where accurate and rapid haemoglobin determinations are required.

Adolescent↗
PubMed1996

A rapid method for the detection of hepatitis C virus RNA by in situ hybridization.

The histologic detection of hepatitis C (Hep C) in paraffin-embedded tissue sections has been problematic. We describe the use of a rapid, i.e., less than 2 hours, in situ hybridization technique to detect Hep C by use of a manual capillary action system (MicroProbe Staining System) and a 24-base synthetic multibiotinylated oligonucleotide antisense probe from the prototype Hep C virus base sequence -16 to -13. This technique is rapid, i.e., it requires a 30-minute hybridization time and easily reproducible, and it uses a nonradioactive detection system, i.e., streptavidin-conjugated horseradish peroxidase. We tested formalin-fixed tissue from explanted human livers and found an overall sensitivity of 69%. Furthermore the technique is highly specific, with negative staining in normal liver tissue from four cases of partial hepatic resection for nontumoric diagnoses and in hepatic tissue obtained from cases of primary biliary cirrhosis, familial amyloidosis, and acute and chronic Budd-Chiari syndrome, for a total of seven confirmed Hep C-negative specimens. Staining with probes for Epstein-Barr virus NotI and EBER sequences was negative in Hep C-positive liver sections from both resected native livers at the time of transplantation and biopsy specimens from post-transplantation patients in whom Hep C has recurred. In those livers staining positively with probe against Hep C, the distribution was both patchy, i.e., staining only fairly well-preserved hepatocytes and not all hepatocytes, and intracytoplasmic, supporting the observations of previously published reports. Finally, the technique was employed on formalin-fixed liver biopsy specimens from four patients with recurrent Hep C; there was repeatedly positive staining in all cases. We think this technique could provide a clinically useful adjunct in the diagnosis of Hep C from formalin-fixed tissue from liver biopsy specimens and that it may be useful in the characterization of the pathophysiologic features of Hep C virus infection.

Base Sequence↗
PubMed1996

[Non-penetrating deep sclerectomy combined with a collagen implant in primary open-angle glaucoma. Medium-term retrospective results].

PURPOSE: To evaluate the middle term tonometric results of a new filtering procedure, the non penetrating deep sclerectomy with collagen device, in primary open-angle glaucoma. This technique aims to eliminate or minimize the complications of classical trabeculectomy. MATERIAL AND METHOD: This procedure has been developed by Koslov et al. Under a limbal-base conjunctival flap and a superficial scleral flap, the ablation of a deep scleral flap takes away the external wall of Schlemm's canal, leaving only the Descemet membrane. A visible filtration across the opened Schlemm's canal and Descemet membrane is obtained. To improve the aqueous filtration, a cylindric collagen device, made from biocompatible porcine scleral tissue, known for its high water content, is fixed in the deep scleral bed with a 10/0 nylon suture. This device provides a support for the elimination route of aqueous humor and acts like a sponge, carrying the liquid by capillary action. It is sterilized by irradiation. Full guarantee against viral contamination is provided. This procedure ends in one suture (40/0 nylon) of superficial scleral flap and conjunctival closing suture. We conducted a retrospective study. Our material included 159 patients (92 males, 65 females), 2/9 eyes. The mean age was 65 years (11-91). The mean follow-up : 8 months (3-20). The types of glaucoma were: POAG: 183 eyes; juvenile POAG: 18 eyes: pigmentary glaucoma: 11 eyes; capsular glaucoma: 7 eyes, 58 eyes (40 patients) presented one or several risk factors of failure for filtering surgery. RESULTS: The mean pre-operative IOP was 24 mmHg +/- 6.60; 15.7 +/- 5.30 at the end of the follow-up (delta average IOP: 9.1 +/- 7.1). The probability success rate (IOP < or = 20 mmHg), according to the Kaplan-Meier Method, was 89% at six months, 75.6% at 16 months. With monotherapy with beta blockers, 79% at 16 months. It was better in the without risk factors group. The mean change in visual acuity was inferior to 0.1 at the end of the follow-up. Except several hyphemas, no complications of the trabeculectomy were observed. The reelevation of IOP was due to an internal obstruction (goniosynechiae or bad filtration), it was treated with Nd-Yag laser with a 2/3 of success rate. External obstruction was treated by 5FU injections into the bleb. CONCLUSION: Non penetrating deep sclerectomy with collagen device can be an excellent alternative to trabeculectomy in open and wide angles. It does not modify visual actuity. It carries less complications than trabeculectomy and the use of antimitotic agents is safer.

Adolescent↗
PubMed1989

Vascular dilatory action of Artemisia capillaris bud extracts and their active constituent.

In perfusion experiments, the acetone extract of Artemisia capillaris buds significantly inhibited the response to norepinephrine of helical strips of rabbit thoracic aorta. The acetone extract was fractionated by column chromatography to identify the active constituent. Kinetic experiments using rabbit thoracic aorta showed that 6,7-dimethoxycoumarin (scoparone) has a marked inhibitory effect on the contractions induced by norepinephrine, 5-hydroxytryptamine, histamine and angiotensin II. Like nitroglycerin, scoparone appeared to be a competitive antagonist of norepinephrine.

Animals↗