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PubMed1995

Interleukin-8 in cerebrospinal fluid from patients with meningitis of different etiologies: its possible role as neutrophil chemotactic factor.

Interleukin (IL)-8 concentrations were analyzed in 70 cerebrospinal fluid (CSF) samples from patients with meningitis of different etiologies and in 34 normal CSF samples. Patient groups included those with pyogenic meningitis, viral meningitis, self-resolving aseptic meningitis without a specific diagnosis, and meningitis of other etiologies and normal CSF from patients with and without neurologic disease. All samples from patients with pyogenic meningitis (18) but only 3 from patients with meningitis of other etiologies and with CSF polymorphonuclear leukocyte (PMNL) counts > or = 80% had IL-8 levels > or = 2.5 ng/mL. IL-8 was above the normal level (< or = 0.5 ng/mL) in samples from 5 of 13 viral and 8 of 23 self-resolving aseptic meningitis patients and in 7 of 13 samples from patients with meningitis caused by other microorganisms. There was a significant relationship between IL-8 levels and CSF PMNL counts in patients with nonpyogenic meningitis. The data suggest a possible role of IL-8 as PMNL chemotactic factor in different infections of the subarachnoid space, not only in pyogenic meningitis.

Adolescent↗
PubMed2006

Detection of Campylobacter jejuni in various lymphoid organs of broiler breeder hens after oral or intravaginal inoculation.

Two studies were conducted to determine whether Campylobacter jejuni could rapidly spread and reside in the internal organs of adult broiler breeder hens. In Study 1, university-housed broiler breeders at 22 wk of age were obtained and placed in individual cages. Each hen was intravaginally inoculated weekly from 23 to 32 wk of age with a characterized strain of C. jejuni. At wk 23, 27, and 32, 4 d postinoculation, the hens were euthanized, defeathered, and aseptically opened. In Study 2, university-housed broiler breeder hens were obtained at 42, 53, and 56 wk of age, placed in individual cages, and inoculated either orally or intravaginally with a characterized strain of C. jejuni. To reduce the possibility of cross-contamination among samples, the thymus, spleen, liver, and gallbladder were aseptically removed, prior to the ceca. In both studies, all samples were individually analyzed. In Study 1, at 23 wk of age, C. jejuni was recovered from 4/7 thymii, 2/7 spleens, 5/7 livers and gallbladders, and 6/7 ceca. At 27 wk of age, C. jejuni was recovered from 1/7 thymii and 1/7 ceca. At 32 wk of age, C. jejuni was recovered from 4/11 thymii, 1/11 livers and gallbladders, and 2/11 ceca. In Study 2, C. jejuni was recovered from 2/6 thymii and 5/6 ceca after oral inoculation and 1/6 spleens, 1/6 livers and gallbladders, and 4/6 ceca after vaginal inoculation of 43-wk-old hens. Campylobacter jejuni was recovered from 2/5 thymii, 3/5 spleens, 3/5 livers and gallbladders, and 2/5 ceca after oral inoculation of 53-wk-old hens and 1/5 thymii and 1/5 livers and gallbladders after vaginal inoculation. Campylobacter jejuni was recovered from 1/4 thymii, 2/4 livers and gallbladders, and 1/4 ceca and was not detected in any vaginally inoculated birds of 57-wk-old hens. This study provides evidence that C. jejuni can reside in the internal organs of broiler breeder hens following oral or intravaginal inoculation.

Administration, Intravaginal↗
PubMed2000

Evaluation of batch and semicontinuous application of high hydrostatic pressure on foodborne pathogens in salsa.

The effects of high hydrostatic pressure (HPP; 545 MPa) on strains of Escherichia coli O157:H7, Listeria monocytogenes, enterotoxigenic Staphylococcus aureus, and nonpathogenic microorganisms were studied in tomato-based salsa. Products were evaluated for the survival of the inoculated pathogens following HPP treatment and after storage at 4 degrees C and 21 to 23 degrees C for up to 2 months. Inoculated samples without HPP treatment, stored under the same conditions, were also evaluated to determine the effects of the acid environment of salsa on the survival of inoculated strains. None of the inoculated pathogens were detected in the HPP-treated samples for all treatments throughout the storage period. Inoculated pathogens were detected in the non-HPP-treated samples stored at 4 degrees C after 1 month, with L. monocytogenes showing the highest level of survivors. In the non-HPP-treated samples stored at 21 to 23 degrees C, E. coli and S. aureus were not detected after 1 week, but L. monocytogenes was detected in low levels. Studies with nonpathogenic strains of the pathogens were conducted at Oregon State University using HPP treatments in a semicontinuous production system. The nonpathogenic microorganisms (E. coli, Listeria innocua, Listeria welshimeri, and nonenterotoxigenic S. aureus) were inoculated together into a feeder tank containing 100 liters of salsa. Microbiological results of samples collected before HPP treatment and from the aseptic filler were similar to those obtained for the pathogenic strains. No survivors were detected in any of the HPP-treated samples.

Bacteria↗
PubMedDate not supplied

Comparison of California Mastitis Test (CMT), Somatic Cell Counts (SCC) and bacteriological examinations for detection of camel (Camelus dromedarius) mastitis in Ethiopia.

A total of 956 quarter milk samples from 253 traditionally managed lactating camels were collected aseptically from Negele (Borena Region), Dire Dawa, and Gewane (Afar Region), Ethiopia, according to multi-stage sampling. The quarter milk samples were subjected to California Mastitis Test (CMT), Somatic Cell Counts (SCC) and bacteriological examinations. Five hundred and seventy one (59.7%) quarter milk samples had microorganisms. Of these, 428 (75.0%) had isolates that were identified as major pathogens (MAP) and 143 (25.0%) as minor pathogens (MIP). A positive correlation was found between CMT scores and bacteriological classes (MAP, MIP) (p-value = 0.00). Strong correlation (p-value = 0.00) between CMT scores and SCC was recorded. The differences among the median log SCC of bacteriological classes (MAP, MIP) were not significant (p-value = 0.24). Similarly, the application of the cut-off level of 2.5 x 10(5) ml(-1) indicated less agreement (p-value = 0.32) for bacteriological classes MAP and MIP.

Animals↗
PubMedDate not supplied

Statistical analysis of environmental monitoring data: does a worst case time for monitoring clean rooms exist?

To determine the relationship between the sampling time of the environmental monitoring, i.e., viable counts, in aseptic filling areas and the microbial count and frequency of alerts for air, surface and personnel microbial monitoring, statistical analyses were conducted on 1) the frequency of alerts versus the time of day for routine environmental sampling conducted in calendar year 1994, and 2) environmental monitoring data collected at 30-minute intervals during routine aseptic filling operations over two separate days in four different clean rooms with multiple shifts and equipment set-ups at a parenteral manufacturing facility. Statistical analyses showed, except for one floor location that had significantly higher number of counts but no alert or action level samplings in the first two hours of operation, there was no relationship between the number of counts and the time of sampling. Further studies over a 30-day period at the floor location showed no relationship between time of sampling and microbial counts. The conclusion reached in the study was that there is no worst case time for environmental monitoring at that facility and that sampling any time during the aseptic filling operation will give a satisfactory measure of the microbial cleanliness in the clean room during the set-up and aseptic filling operation.

Drug Industry↗
PubMed2004

Effect of 24-hour intravenous tubing set change on the sterility of repackaged fat emulsion in neonates.

BACKGROUND: Duration of intravenous fat emulsion (IVFE) infusions, precise method of administration (manufactured bottle vs repackaged syringe), and interval for administration set change continue to be debated. OBJECTIVE: To determine the contamination rate associated with replacing IVFE administration sets every 24 hours in newborn infants receiving fat emulsion repackaged into unit-of-use syringes. METHODS: This was a prospective, microbiologic study of 90 administration sets used in 19 neonates. IVFE samples were obtained from administration sets at the end of a 19- to 23-hour infusion and prior to daily tubing set change from infants who received repackaged IVFE. Samples of IVFE (1-3 mL) were aseptically removed at the catheter connection site proximal to the patient, transferred into BACTEC PEDSPlus culture media, and continuously monitored for 5 days to detect gram-positive and gram-negative organisms, as well as yeast. RESULTS: Two samples (2.27%) grew coagulase-negative Staphylococcus. Both samples were from the same asymptomatic patient and were obtained on consecutive days. A blood sample obtained through this infant's central catheter grew the same organism and suggested catheter hub colonization as the primary site of microbe origin. CONCLUSIONS: Microbial contamination of IVFE infusion sets changed at 24-hour intervals, using unit-of-use syringes in neonates, was low at 2.2%.

Drug Contamination↗
PubMed2005

Growth and toxin production by Clostridium botulinum in steamed rice aseptically packed under modified atmosphere.

Sales and consumption of ready-to-eat aseptic steamed rice products have increased manyfold in Japan over the past 10 years. To determine the safety of steamed rice (water content 60%, pH 6.5) aseptically packaged under modified atmosphere, challenge studies were performed using a mixture of Clostridium botulinum proteolytic strains (five strains of type A and five strains of type B). Atmospheric conditions of 0 and 15% oxygen (with 5% CO2 and 5% N2 as the balance) were used. No neurotoxins were detected, and organoleptically acceptable conditions persisted for 24 weeks at 15% oxygen conditions. However, botulinum neurotoxin was found in one of three samples at 12 weeks and in one of two samples at 24 weeks at 0% oxygen and 30 degrees C. When samples were inoculated with C. botulinum with amylase (0% oxygen), neurotoxin and sample spoilage was detected after only 1 week of storage. Challenge studies using proteolytic strains of C. botulinum mixed with Bacillus subtilis (amylase formers) also were performed with atmosphere conditions of oxygen at 0, 5, 10, and 15% (with 5% CO2 and 5% N2 as the balance). Under 10 and 15% oxygen conditions, neurotoxin was not detected after 1 week of storage, but sample spoilage was detected after the same period. Under 0% oxygen conditions, neurotoxin was detected at 1 week, but the sample remained organoleptically acceptable even after 2 weeks of storage. Both neurotoxin and sample spoilage were detected at 1 week of storage under 5% oxygen conditions. Based on these results, cocontamination of amylase-producing Bacillus with C. botulinum would increase the risk of foodborne botulism when aseptic rice samples are packed under low-oxygen conditions (<5%). Therefore, to ensure the safety of these products, packing under atmospheric containing more than 10% oxygen is recommended.

Botulinum Toxins↗
PubMed1992

A human endometrial explant system: validation and potential applications.

OBJECTIVE: Our objective was to describe an in vitro explant system to study the regulation of prostaglandin production by human endometrium. STUDY DESIGN: Segments of late-luteal-phase endometrium were obtained aseptically at the time of endometrial sampling. The endometrium was cut into 1 mm3 pieces and applied to the polycarbonate membrane of tissue-culture-well inserts for 12-well plates (Costar Transwell cell culture chamber inserts, 0.4 microns pore size). After placing the well inserts, culture medium was carefully applied. The explants were incubated at 37 degrees C in 5% carbon dioxide in air, and the culture medium was changed daily. RESULTS: Electron microscopic examination and lactate dehydrogenase determinations of the explants revealed cellular viability for < or = 5 days of culture. Endometrial explants responded to treatment with interleukin-1 beta and tumor necrosis factor by a concentration-dependent increase in the production of prostaglandin E2. Costimulation of late luteal endometrial explants with interleukin-1 beta (10 ng/ml) and progesterone (10(-6) mol/L) resulted in variable production of prostaglandin E2, suggesting that the histologic examination of the endometrium does not necessarily reflect the functional properties of the endometrium. CONCLUSIONS: Our data show that when used with human endometrial tissue this explant system maintains tissue viability and responsiveness for < or = 5 days. This approach to explant methods is simple and provides a flexible model to study the regulation of the production of bioactive substances by human endometrial tissue.

Culture Techniques↗
PubMed1992

Postscaling bacteremia in HIV-associated gingivitis and periodontitis.

Aseptic venipuncture was used to obtain samples of blood from 22 patients seropositive for human immunodeficiency virus (HIV) with gingivitis (HIV-G) and 19 HIV-seropositive patients with periodontitis (HIV-P), 15 and 30 minutes after the initiation of routine dental scaling and root planing. The presence of colony forming units in 1.2 ml aliquots of blood collected with the Isostate system (DuPont Isostat System, Doraville, Ga.) was assayed on trypticase soy blood agar. Six of the samples from HIV-G subjects were positive for colony forming units 15 minutes after scaling but not at 30 minutes. Similar evidence of bacteremia was found in seven of the HIV-P patients 15 minutes after scaling was initiated in this group, with no microbial growth detectable in samples obtained at 30 minutes. In two HIV-G and three HIV-P patients with demonstrable bacteremias a postoperative fever developed. For both HIV-G and HIV-P groups no significant difference was found between the absolute CD4 T-cell counts of nonbacteremic versus bacteremic patients (p greater than 0.05). These observations suggest that special provisions for antibiotic prophylaxis in this patient group may be unnecessary.

Adult↗
PubMed2004

[Meningitis by Toscana virus in Spain: description of 17 cases].

BACKGROUND AND OBJECTIVE: We aimed to analyze the clinical and epidemiological data from the first series of patients with meningitis by Toscana virus in Spain. PATIENTS AND METHOD: We analyzed a total of 724 cerebrospinal fluid (CSF) samples from patients with suspicion of aseptic meningitis for virus isolation in cell culture. The clinical records of patients in whom Toscana virus was isolated were analyzed. RESULTS: Toscana virus was isolated in CSF in 17 patients (7% of all viral isolates). The first case was diagnosed in June 1988 and the last one in August 2002. The mean age was 27 years (range: 10-64 years). Most patients were based in rural area (n = 11, 64.7%). Most common symptoms were headache (holocranial or focal) present in all patients and moderate fever observed in 76.5% of them with a mean duration of 48 h (range: 18 h-5 days). Nuchal rigidity was present in 9 patients (53%). All cases were seen between June and October, and predominantly in August (53%). The outcome was favorable in all cases, and the mean time of duration of the disease was 7 days (range: 3-10 days). CONCLUSIONS: Toscana virus must be taken into account among those agents responsible of lymphocytic meningitis in Spain.

Adolescent↗
PubMed2002

The relationship between odontogenic bacteraemia and orthodontic treatment procedures.

The purpose of this research was to estimate the prevalence and intensity of bacteraemia associated with orthodontic treatment procedures. The four procedures investigated were: an upper alginate impression, separator placement, band placement, and adjustment of an archwire on a fixed appliance. Eighty-one children undergoing general anaesthesia (GA) for dento-alveolar surgery related to their orthodontic treatment were randomly allocated to the impression or separator group. A further 61 children, receiving treatment in the Outpatient Department, were included and randomly allocated to the banding or archwire adjustment groups. A cannula was inserted into either the left or right antecubital fossa using an aseptic technique. A baseline 6 ml sample of blood was taken before treatment and a second 6 ml sample was taken 30 seconds after the procedure. There was no significant difference in the number of positive blood cultures between baseline (nine, 23 per cent), and following an upper alginate impression (twelve, 31 per cent); between baseline (twelve, 27 per cent), and placement of a separator (fifteen, 36 per cent); between baseline (nine, 36 per cent), and fitting or placement of a band (eleven, 44 per cent); or between baseline (twelve, 33 per cent), and archwire adjustment (seven, 19.4 per cent). For the separator group only the mean total number of aerobic and anaerobic bacteria combined, isolated from the blood samples (cfu of bacteria per ml of blood), was significantly greater following the placement of a separator (2.2, SD 9.1), compared with baseline (0.9, SD 0.2; P < 0.02). This investigation demonstrates that the only orthodontic treatment procedure that causes a significant bacteraemia is the placement of a separator.

Adolescent↗
PubMed1994

Antibacterial susceptibility of bovine-mastitis pathogens tested directly in milk from infected quarters.

Antibacterial susceptibilities of bovine-mastitis pathogens were analysed directly in 57 mastitic milk samples without inoculation with exogenous organisms. Aseptically collected milk was mixed with serial dilutions of antibacterials and the growth was observed using 2,3,5-triphenyltetrazolium chloride (TTC) reduction the following day. The results were compared with those obtained by using calibrated bacterial inocula in turbidimetric minimum-inhibitory-concentration (MIC) determination in broth cultures, and in TTC-broth culture-test and TTC-normal milk-test. The results of different methods all correlated positively when the entire data was used. However, taking the direct test in mastitic milk as the 'true' result, the total discrepancies varied from 34.7% to 48.8%. Antibacterial activities of the trimethoprim-sulphadoxine combination, and of spiramycin and ampicillin, decreased significantly when nutrient broth was replaced by milk as the test medium. The efficacy of trimethoprim-sulphadoxine as an antibacterial agent was also dependent on the source of milk.

Animals↗
PubMed1998

Totally implantable venous access devices in children with cystic fibrosis: incidence and type of complications.

BACKGROUND: Totally implantable vascular access devices (TIVADs) are accepted as a safe and effective method of facilitating long term intravenous therapy. We report our experience of the use of these devices in children with cystic fibrosis with a particular focus on the incidence and type of complications. METHODS: The medical records of patients with cystic fibrosis who underwent placement of a TIVAD at the Royal Children's Hospital, Melbourne, Australia from January 1987 to October 1996 were reviewed. Venous ultrasonography with Doppler was performed in surviving patients with a TIVAD in situ from November 1996 to April 1997 to detect occult thrombotic complications. RESULTS: A total of 57 TIVADs were implanted in 44 children with a median functional duration of 700 days (range 27-3347 days). Twenty one children had devices inserted without complications. Forty eight complications (30 mechanical, 18 infectious) occurred in 36 devices in 23 children during a total functional duration of 53,057 catheter days. Mechanical complications occurred in 53% of devices (one per 1712 catheter days). Symptomatic venous thrombosis occurred five times in four patients (9%). Infectious complications occurred in 32% (one per 2948 catheter days) while sepsis occurred in five devices (9%). Doppler ultrasonography detected unsuspected thrombosis in two of 10 patients examined. CONCLUSIONS: While TIVADs provided effective long term intravenous access, septic and thrombotic complications caused significant morbidity in this population. Careful patient selection, adherence to aseptic technique for access and blood sampling, and periodic ultrasonography with Doppler to detect early thrombosis may help reduce these risks.

Adolescent↗
PubMed2005

[Investigations on the occurrence as well as the role of Demodex follicuforum and Demodex brevis in the pathogensis of blepharitis].

PURPOSE: The aim of the paper was to describe the prevalence and the role of Demodex folliculorum and Demodex brevis in the pathogenesis of chronic blepharitis. MATERIAL AND METHODS: Examinations were carried out on a group of 435 people aged from 3 to 96 years. A sample of four eyelashes were taken aseptically from each individual and later studied under a light microscope. Infection of Demodex was classified on the basis of presence of mature and larval forms or after observing chitinous exuviae affixed to the studied eyelashes. RESULTS: It has been concluded that Demodex occurs among: 13% of the people aged from 3 to 15 years; 34% of the people aged from 19 to 25 years; 69% of the people aged from 31 to 50 years; 87% of the people aged from 51 to 70 years and 95% of the people aged from 71 to 96 years. It has been observed that 58% of the people infected with Demodex suffer from chronic blepharitis. It was also found that Demodex frequently occurs among people taking care of the elderly and among students of the Medical School. CONCLUSIONS: (1) Demodex folliculorum and Demodex brevis are an etiological factor in chronic blepharitis. (2) With age the prevalence of infection of Demodex rises. (3) People taking care of the elderly and students of Medical Schools are at higher risk of being infected with Demodex.

Adolescent↗
PubMed1987

In-vitro production of nitrosamines by bacteria isolated from the operated stomach.

Evidence is presented of in-vitro catalysis of nitrosation by organisms isolated from the hypoacidic operated stomach. Subjects taking part in a prospective study of potential premalignancy after benign ulcer surgery underwent endoscopy, and samples of gastric juice were obtained aseptically. The organisms present were identified using the API system and tested for their ability to catalyse the nitrosation of the secondary amine, morpholine, at neutral pH and 37 degrees C. Four of the five species tested were found to be capable of the catalysis. Cellular disruption and denaturation of protein abolished the catalytic ability, suggesting that the catalysis is mediated by an enzymic system. Osmotic shock experiments indicate that the enzyme site may be on the inner membrane.

Female↗
PubMedDate not supplied

Isolation of Salmonella from ovaries and oviducts from whole carcasses of spent hens.

Spent hens containing hard-shelled eggs were obtained to study the influence of sample collection and sample preparation methodology on the detection of Salmonella in ovaries. Four hundred eighteen birds from 19 flocks were collected, and the carcasses were opened aseptically within 8-12 hours of collection. A sample set containing hard-shelled egg, ovary, and oviduct section were collected from each carcass, and surface contaminants were removed from ovaries with polyoxyethylene ether. Three of 19 flocks (15.8%) and six of 407 ovary samples were positive for Salmonella; two oviduct samples were positive (0.5%). No eggs were Salmonella-positive. Single and multiple serotypes were detected in ovaries. Results indicated that Salmonella recovery rates can be significantly affected by speed in processing samples after collection, by cleanliness of the tissue-collection environment (laboratory vs. slaughter plant), and by removal of surface contaminants.

Animals↗
PubMed1993

Compatibility and stability of ondansetron hydrochloride, dexamethasone, and lorazepam in injectable solutions.

The stability of ondansetron hydrochloride, dexamethasone sodium phosphate, and lorazepam in 5% dextrose injection or 0.9% sodium chloride injection in polyvinyl chloride (PVC) minibags and glass bottles was studied. Triplicate solutions of 8 or 32 mg of ondansetron (as the hydrochloride salt) mixed with 20 mg of dexamethasone phosphate (as the sodium salt) with or without 2 mg of lorazepam were compounded in 50-mL PVC minibags and glass bottles containing either 5% dextrose injection or 0.9% sodium chloride injection and stored at 23-25 degrees C. Duplicate measurements were performed when drugs were added and at 1, 2, 4, 8, and 24 hours after addition. Samples of the 32-mg ondansetron admixtures were collected under aseptic conditions to inspect for precipitation and to count particles with a laser particle analyzer. Samples of all admixtures were evaluated for chemical stability by stability-indicating high-performance liquid chromatography. Ondansetron hydrochloride and dexamethasone were physically compatible and chemically stable for up to 24 hours under the study conditions. The concentration of lorazepam in PVC containers dropped below 90% of the original concentration within four hours. In addition, particle counts in lorazepam-containing solutions were higher when 0.9% sodium chloride injection was the diluent than when 5% dextrose injection was the diluent. In admixtures containing all drugs, ondansetron hydrochloride and dexamethasone sodium phosphate in 5% dextrose injection or 0.9% sodium chloride injection were stable for up to 24 hours when stored in PVC bags or glass bottles.(ABSTRACT TRUNCATED AT 250 WORDS)

Dexamethasone↗
PubMed2006

[Method for assessment of distribution of UHMWPE wear particles in periprosthetic tissues in total hip arthroplasty].

PURPOSE OF THE STUDY: Aseptic loosening of implants is the main complication affecting the longevity of joint prostheses. The highest proportion of loosening occurs due to osteolysis produced by the presence of ultra-high molecular weight polyethylene (UHMWPE) wear particles smaller than 1 microm. These can be identified by microscopic, spectroscopic or light-scattering methods. Here we describe our method for counting wear particles, based on the principle of light scattering. MATERIAL AND METHODS: Between 2002 and 2004, we collected samples of polyethylene granuloma in 19 patients who underwent revision total hip arthroplasty (THA) for aseptic loosening. The samples were obtained from strictly defined areas corresponding to the radiographic presentation of periprosthetic zones describes by Gruen and DeLee in THA. The frozen samples were lyophilized and subjected to delipidation and hydrolyzation procedures in 65 % HNO3. The top part of solution containing wear particles was blended with isopropanol, and the mixture was filtered through a 10-microm polycarbon membrane. Subsequently, the filtrate was filtered through a 0.1-microm membrane. Membranes with trapped particles, 0.1 to 1.0 microm in size, were sent for particle characterization and quantification. The number of wear particles was measured by the method based on light scattering with calibration (LSC), using a Beckman Coulter LS230 analyzer that can express particle size distribution in a given volume in percent. The method was based on the fact that each particle reflects rays that can be measured. The medium measured contained an unknown number of UHMWPE particles and a known number of calibration glass beads varying in size. The number of UHMWPE particles was calculated from the known number of calibration beads. RESULTS: Because the collected samples were also used to develop the method, comprehensive data was obtained in six patients only. Particle distribution recorded in the periprosthetic zones in THA varied greatly; up to a five-fold difference in particle concentration was observed between the zones. In five of the six patients, the highest particle concentration was found in zone III. DISCUSSION: Seeking a method that would be exact, quick and cheap and would eliminate particle aggregation remains the subject of study for researchers cooperating with clinical practice. At present methods based on weighing isolated particles are used most frequently. We developed the LSC method that, for quantification, utilizes the ability of particles to disperse light, and allows us to calculate the real numbers of UHMWPE wear particles in a medium containing a known number of calibration particles. Although this is an indirect method, it gives more accurate results than the direct weighing of particles. The advantages of the LSC method involve less demand on sample purity, greater speed and low limits of detection. The method is useful for statistical evaluation of a larger number of samples. The variation in particle distribution in THA found in this study is in agreement with the relevant literature data; it is also in agreement with our assumptions and clinical findings. CONCLUSIONS: The authors developed an original method for assessment of UHMWPE wear particles in tissue samples, which is quicker than the methods so far used. In the periprosthetic tissues studied, particles about 1 microm in size were detected; their numbers (about 1010 particles per gram dry tissue) are in agreement with the literature data. The distribution of particles in periprosthetic zones in THA was uneven. The highest number of particles was found in the neighboring zone III and zone 7, as described by Gruen and DeLee. Key words: wear, polyethylene, total hip arthroplasty, light scattering, aseptic loosening, wear particles.

Arthroplasty, Replacement, Hip↗