Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “STERILITY”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,459 records · Page 81Linked to original sources
PubMed1976

Microbiological hazard from the exhaust of a high-vacuum sterilizer.

Data are presented which show the potential for release of viable microorganisms into the atmosphere from high-vacuum steam sterilizers during the evacuation cycle preceding application of steam under pressure. Bacillus subtilis var. niger spores, Serratia marcescens cells, and T1 coliphage disseminated into the sterilizer chamber as small particles from liquid suspensions, and dried spores of B. subtilis var. niger distributed on bulk discard materials were recovered from the atmosphere around pipes venting steam from the steam ejectors used to create chamber vacuum. Evaluation of the hazard involved is discussed, and the design, fabrication, and installation of a valved filter system for preventing release of viable microorganisms are presented. The filtration system utilized an F-700 water-resistant filter and was shown to eliminate the release of viable airborne microorganisms from a high-vacuum sterilizer. A method is presented for determining size requirements for an atmospheric vent filter in relation to the volume of a sterilizer.

Air Microbiology↗
PubMed1986

Bioluminescence for USP sterility testing of pharmaceutical suspension products.

Bioluminescence measurement significantly improved the accuracy, sensitivity, precision, and reliability of the current visual endpoint determination for the USP sterility test and eliminated the day 7 transfer/dilution step required for testing suspension products. Thirteen strains of bacteria and fungi (representing potential contaminants in sterile products), three pharmaceutical suspension products, and four media were used in the experiment. No interference from suspension products was encountered in the detection of microbial growth by the bioluminescence measurement. The poor fungal growth encountered was attributed to insufficient diffusion of oxygen into the medium and was circumvented by use of a large tube size (38 by 200 mm) or by vortexing the medium once during the 2-week incubation period. Bioluminescence measurement would facilitate automated handling of the sterility test endpoint readout operation. The optimum parameters of bioluminescence measurement for application in sterility testing were determined.

Bacteria↗
PubMed2001

Effects of rice seed surface sterilization with hypochlorite on inoculated Burkholderia vietnamiensis.

When a combination of hydrogen peroxide and hypochlorite was used to surface sterilize rice seeds, a 10(2)- to 10(4)-fold decrease in CFU was observed during the first 15 h after inoculation of the rice rhizosphere organism Burkholderia vietnamiensis TVV75. This artifact could not be eliminated simply by rinsing the seeds, even thoroughly, with sterile distilled water. When growth resumed, a significant increase in the frequency of rifampin- and nalidixic acid-resistant mutants in the population was observed compared to the control without seeds. This phenomenon was a specific effect of hypochlorite; it was not observed with hydrogen peroxide alone. It was also not observed when the effect of hypochlorite was counteracted by sodium thiosulfate. We hypothesized that the hypochlorite used for disinfection reacted with the rice seed surface, forming a chlorine cover which was not removed by rinsing and generated mutagenic chloramines. We studied a set of rifampin- and nalidixic acid-resistant mutants obtained after seed surface sterilization. The corresponding rpoB and gyrA genes were amplified and sequenced to characterize the induced mutations. The mutations in five of seven nalidixic acid-resistant mutants and all of the rifampin-resistant mutants studied were found to correspond to single amino acid substitutions. Hypochlorite surface sterilization can thus be a source of artifacts when the initial bacterial colonization of a plant is studied.

Anti-Bacterial Agents↗
PubMed1967

Synergistic effects in sonochemical sterilization.

The synergistic effects observed during the sterilization of Bacillus subtilis var. niger ATCC 9372 by the combined action of ethylene or propylene oxide with high-intensity airborne sound waves (34.8 kc/sec) were investigated. It has been shown that the number of surviving spores deposited on paper strips decreases exponentially with the sound intensity at sample level. Reductions of the order of one-third of the time required for standard propylene oxide sterilization have been observed by using the combined action of sound waves with gaseous sterilization. At the present time, maximal synergistic effects seem to be achieved for the following experimental conditions: propylene oxide concentration, 500 to 1,000 mg/liter; acoustic intensity, 161 to 162 db; contact time, 80 min; temperature, 60 C; and relative humidity, 40%. The basic mechanism involved in sonochemical sterilization seems to be more of a physical (accelerated gas diffusion) than a chemical nature.

Bacillus subtilis↗
PubMed1968

Heat sterilization of water in a large open vessel.

A safe, convenient, and economical method of preparing and dispensing a large volume of sterile water in a movable container is described. A caster-mounted, rectangular, 100-gal, stainless-steel water tank was fabricated. An audible, solid-state water-level alarm was developed for use with a detachable sensing probe that could be autoclaved. A filter system was constructed to allow the tank to be autoclaved as an open vessel. Thermocouples were mounted within the tank of water to study the time-temperature relationships of the water during the sterilization cycle. In a downward displacement autoclave with a hot jacket, 75 min were required for the water temperature to rise from 140 to 240 F (60 to 116 C). A total of 3 hr for heating and holding includes an adequate safety factor to insure the sterility of the water immediately after autoclaving. The long-term sterility of the water and the safety of the system were verified by using the water to maintain a germ-free animal colony.

Hot Temperature↗
PubMed1974

Storage of stock cultures of filamentous fungi, yeasts, and some aerobic actinomycetes in sterile distilled water.

Castellani's procedure for maintaining cultures of filamentous fungi and yeasts in sterile distilled water was evaluated. Four hundred and seventeen isolates of 147 species belonging to 66 genera of filamentous fungi, yeasts, and aerobic actinomycetes were maintained in sterile distilled water at room temperature over periods ranging from 12 to 60 months in four independent experiments. Of the 417 cultures, 389 (93%) survived storage in sterile distilled water. The selection of good sporulating cultures and sufficient inoculum consisting of spores and hyphae suspended in sterile distilled water were the most important factors influencing survival in water over a longer period of time. The technique was found to be simple, inexpensive, and reliable.

Actinomycetales↗
PubMed1998

Biocompatibility differences with respect to the dialyzer sterilization method.

The impact of the method of sterilization (steam vs. ethylene oxide, ETO) on indices of biocompatibility is investigated using polysulfone membranes. Eight patients were treated with a random choice of the high-flux membranes F60S (steam) and F60 (ETO) and the low-flux membrane F6 (ETO). Blood samples were taken prior to and 5, 15, 30, 60, and 180 min after the start of hemodialysis. White blood cell count, platelet count, and plasma concentrations of polymorphonuclear neutrophil elastase, complements C3a and C5a, and beta2-microglobulin were determined. The dialysis procedure was associated with a significant decrease in white blood cell count and beta2-microglobulin level and a significant increase in polymorphonuclear neutrophil elastase and complement C3a and C5a levels. However, the steam-sterilized F60S membrane had a significantly lower impact on the biocompatibility indices than the ETO-sterilized F60 and F6 membranes (p < 0.05 or p < 0.001 for the individual markers). We conclude that using steam instead of ETO for sterilization may improve the biocompatibility of membranes.

Adult↗
PubMed2004

'Clean dialysate' requires not only lower levels of endotoxin but also sterility of dilution water.

Clean dialysate should be used in dialysis with a high-flux dialysis membrane to avoid contamination of endotoxin into blood circuits. For this purpose, we should not only clean up the end stream dialysate by endotoxin-cut filters, but also prevent bacterial growth in dilution water lines. Delivery lines of the prepared dialysate from a central dialysate-supplying machine are sterilized in all dialysis facilities, but those of the dilution water in cases of using personal dialysis machines are not sterilized in most facilities in Japan. In our dialysis department, the endotoxin level in the dilution water lines decreased to <50 EU/l in 3 weeks by sterilization with a low concentration of sodium hypochlorite (30-100 ppm) once a week from the peak level of >1,000 EU/l just after the start of sterilization.

Dialysis Solutions↗
PubMed1976

3H-Estradiol uptake and retention by target tissues of light-sterilized female rats.

Tissue distribution of radioactivity was studied at 2, 4 and 6 h after intravenous injection of 3H-estradiol-17beta (41.7 ng/100 g b.w.) in 12 light-sterilized and 11 control female rats ovariectomized 72 h prior to injection. Female rats were light-sterilized by exposure to continuous illumination for 82 days and, based on the duration of continuous vaginal cornification and the absence of corpora lutea at post-mortem histological examination of the ovaries, were anovulatory for at least 30 days prior to injection. Control rats were housed under conditions similar to the experimentals except that they were exposed to alternating lighting (14 h light:10 h dark). They remained ovulatory throughout the experiment. Uterine 3H-estradiol uptake and retention were significantly depressed in the light-sterilized group. There were no significant differences in 3H-estradiol uptake or retention as a result of light-sterilization in any of the other tissues studied, including anterior, middle, and posterior hypothalamus, hippocampus, amygdala, cerebrum, anterior pituitary and plasma. The failure to detecta reduction in neural 3H-estradiol uptake demonstrates that the anovulatory state can exist without a concomitant reduction in the hypothalamic estrogen binding capacity. The possibility is discussed that the decreased target tissue binding noted in various types of anovulatory animals is the result, not the cause, of altered ovarian function.

Amygdala↗
PubMed1988

Reducing the amount of monomers in intraocular lenses through sterilization by gamma radiation.

Sterile inflammatory reactions of varying degrees are a rare, but not uncommon, complication after intraocular lens implantation. At present we still do not know the cause of these processes, but we consider two chemical substances contained in the lens at least as risk factors for them: monomeric methyl methacrylate, which is present in any lens made from polymethyl methacrylate (Perspex), and ethylene oxide, an extremely toxic agent, which is absorbed by the lens during sterilization with this gas. Gas chromatographic investigations show that under sterilization of intraocular lenses by 60Co radiation the amount of monomeric methyl methacrylate in the lens can be reduced drastically. Also, any contamination of the lens by ethylene oxide is avoided. Therefore, at least two important arguments speak in favor of this alternative sterilization technique.

Chromatography, Gas↗
PubMed1983

Catamnestic examinations performed after the utilization of two different sterilization techniques.

By using a patient questionnaire, we checked the effects on sterilization of the unipolar high-frequency current method and the endocoagulation procedure in relation to late complications. In the years following high-frequency sterilization, 23 women (8.9%) were hysterectomized; in the endocoagulation group only 9 patients (2.3%) underwent hysterectomy, primarily because of the recurrence of therapy-resistant menometrorrhagia. Of those women sterilized by the unipolar HF technique, 20 (7.8%) required 1-3 postoperative curettages, whereas only 8 patients (2.1%) of the endocoagulation group required such an operation. We found that 79 patients of the HF group (30.9%) exhibited menstrual disorders compared to only 45 women (11.7%) in the endocoagulation collective. By disregarding those patients who had taken the pill or used an IUD prior to sterilization, the corrected rates for occurrence of menstrual irregularities were 22.5% for the HF group and 5.9% for the endocoagulation group, respectively.

Adult↗
PubMed2004

Sterilized, freeze-dried amniotic membrane: a useful substrate for ocular surface reconstruction.

PURPOSE: To examine the feasibility of using sterilized, freeze-dried amniotic membrane (FD-AM) as a substrate for cultivating autologous corneal epithelial cells for ocular surface reconstruction. METHODS: Human AM deprived of amniotic epithelial cells by incubation with EDTA was freeze dried, vacuum packed, and sterilized with gamma-irradiation. The resultant FD-AM was characterized for its physical, biological, and morphologic properties by stretch stress tests, immunohistochemistry, electron microscopy, and cell culture. In addition, 3 weeks after an ocular surface injury, the conjunctivalized corneal surfaces of eyes in eight rabbits were surgically reconstructed by transplantation of autologous cultivated corneal epithelial cells on FD-AM. RESULTS: A stretch stress test revealed no significant differences between sterilized FD-AM and cryopreserved AM. Immunohistochemistry for several extracellular matrix molecules and electron microscopic analysis of FD-AM revealed that the process of drying and irradiation did not affect its biological and morphologic properties. The corneal epithelial cells cultivated on FD-AM had four to five stratified, well-differentiated cell layers. Corneas that were grafted with the cultivated corneal epithelial cells on FD-AM were clear and were all epithelialized at 10 days after surgery. CONCLUSIONS: The sterilized, freeze-dried AM retained most of the physical, biological, and morphologic characteristics of cryopreserved AM; consequently, it is a useful biomaterial for ocular surface reconstruction.

Amnion↗
PubMed1983

Sterilization of infant formula.

A survey of 237 pediatricians currently practicing in Connecticut revealed that 97 (41%) recommend routine sterilization of infant formula for a mean of 4.4 months. Eight bottles of proprietary formula were prepared in a controlled manner: four utilizing the "terminal heating method" of sterilization and four utilizing the "clean method" without sterilization. While the "terminal heating method" resulted in less bacterial contamination, three of the bottles prepared by the "clean method" had negative coliform counts and the other bottle had a minimal count. Ten bottles prepared without sterilization were randomly selected from mothers who had brought their infants for well-child care. With the exception of a small inoculum of enterotoxin-producing Staphylococcus aureus in one bottle, no enteropathogens were identified. The implications of this study for the routine preparation of infant formula are discussed.

Food Handling↗
PubMedDate not supplied

Sterile preparation of the external auditory canal with povidone-iodine.

Sterile preparation of the external auditory canal is usually not undertaken, although the external auditory canal provides surgical access for several procedures involving the tympanic membrane, middle ear, and vesibule. This is due to the rarity of postoperative wound infections, as well as difficulty in sterilizing the external auditory canal. Four antiseptic solutions commonly used for operative preparation were tested to determine thrir potential for sterilizing the external auditory canal. Povidone-iodine solution was effective in sterilizing 90% of the external auditory canals of children and adults. This simple technique may find clinical use in surgical procedures involving the external auditory canal.

Acetone↗
PubMed1977

Standards of cleansing and sterilization of infant feeding utensils in the home.

Microbiological standards achieved by mothers when sterilizing babies' feeding utensils in the home were studied in the Slough area in England. Results indicated a marked improvement in this aspect of baby hygiene when compared to results of a similar survey conducted in the town of Reading, England, in 1970. Previously, 78% of bottles and 70% of the teats were recorded as being satisfactorily sterilized. During this study the number of sterile bottles had risen to 98.1%, sterile teats to 90-6%. These improved standards may be an indication of better education of mothers.

Bottle Feeding↗
PubMedDate not supplied

Allograft transplantation in the knee: tissue regulation, procurement, processing, and sterilization.

Use of musculoskeletal allografts has become increasingly popular, with widespread use among knee surgeons. The advantages and disadvantages of their use have been documented. In the knee, allografts are used for ligament reconstruction, meniscal transplantation, and articular surface reconstruction. The purpose of this review is to present issues surrounding the allograft industry, including regulation of tissues and tissue banks and procurement, processing, sterilization, and storage of allograft tissue. Tissue bank regulation is ultimately under the jurisdiction and authority of the Food and Drug Administration; some individual states regulate tissue banks. The American Association of Tissue Banks is a scientific organization that encourages education, research, and voluntary accreditation of tissue banks. It promotes safety and standards for retrieval, processing, storage, and distribution of transplantable human tissue. Allograft tissues are generally harvested and processed aseptically, which may not prevent contamination. Tissue sterilization is difficult and controversial. Tissue banks historically have used one of two methods of sterilization, ethylene oxide or gamma radiation. Both methods have risks and benefits. Newer methods of sterilization are being developed. Allograft tissue that is not transplanted fresh can be freeze-dried or deep frozen for storage. Ultimately, allograft transplantation in the knee facilitates knee form and function and enhances the patient's quality of life. Orthopaedic surgeons who use allograft tissue must understand the tissue banking process to provide safe and effective tissues to their patients.

Cartilage, Articular↗
PubMedDate not supplied

Evaluation of heat sterilization of commercial rat diets for use in FDA toxicological studies.

Certified commercial rat diets, control and fortified, in the form of pellets and meal, were evaluated in a simulated subchronic rat feeding study. The diets were analyzed before and after autoclaving to determine nutrient integrity and loss, as well as the efficiency of autoclaving for removal of microbiological contaminants. Sterilization reduced the level of heat-labile vitamins, but protein level was minimally reduced. Sterilization eliminated most of the bacterial contaminants and virtually all the mold and yeast colonies. Male and female Osborne-Mendel rats (3-4 wk old) were fed control or sterilized diet for 6 wk. Both males and females consumed more pelleted chow than meal chow. This apparent difference in consumption may be due to wastage of pellets, because there were no differences in male or female growth during the 6-wk study. At necropsy, no gross pathology was noted, and organ weights did not differ significantly among the groups for either sex. Testicular weights were also similar among the groups. Blood serum proteins were analyzed by electrophoresis to screen for possible effects on various target organs. Gamma globulin levels for female rats fed sterilized meal were significantly reduced compared to levels for rats fed the control diet. These results suggest that either nutritional factors or heat inactivation of the microbes affects basal levels of humoral immunity, possibly by reduction of gut-mediated immune responses.

Animal Feed↗
PubMed2000

Comparison of gas plasma and gamma irradiation in air sterilization on the delamination wear of the ultra-high molecular weight polyethylene used in knee replacements.

Early failure of knee replacements is thought to be due to the combination of sterilization by gamma irradiation in air and the high cyclic stresses that they endure during use. Such failures are shown through delamination and permanent deformation of the ultra-high molecular weight polyethylene (UHMWPE) component. This study investigated whether gas plasma sterilization, as an alternative to gamma irradiation in air, would give better performance after ageing in a knee replacement using a metal pin on polymer plate wear test. Fourier transform infrared (FTIR) analysis was performed on the components to assess oxidation levels and a finite element stress analysis model is presented to estimate strain at failure in the UHMWPE. Delamination occurred in the majority of the gamma-irradiated plates but did not occur in any of the gas-plasma-sterilized plates. The FTIR analysis showed that the plates gamma irradiated in air were highly oxidized when compared with the gas-plasma-sterilized plates. Plastic strain at failure was determined for the gamma-irradiated plates and found to be less than 2.4-14 per cent.

Equipment Failure Analysis↗