Effects of algal extracts (Polysiphonia fucoides) on rainbow trout (Oncorhynchus mykiss): a biomarker approach.

The genotoxicity of algal extracts (Polysiphonia fucoides) was investigated in erythrocytes of rainbow trout (Oncorhynchus mykiss). Trout were exposed to 0.5% of the algal extract for 7 days. Comet assay (alkaline and neutral versions) and Micronucleus test were used to assess DNA damage, and Diffusion Assay to detect apoptotic cells. EROD activities and oxidative stress parameters in rainbow trout liver were also measured. A significant induction of DNA single strand breaks comparable to the ones induced by the in vivo exposure to 20 mg/kg B[a]P was observed at the end of the treatment, while increases of double strand breaks and apoptotic cells were not observed. The absence of activation of antioxidant responses seems to underline a mechanism of action of the genotoxic algal extract which does not involve oxidative stress.

Polybrominated diphenyl ethers (PBDEs) and their methoxylated derivatives in pike from Swedish waters with emphasis on temporal trends, 1967-2000.

Temporal trends of five tetra- to hexabromodiphenyl ethers [BDE47, BDE99, BDE100, BDE153 and BDE154) and two methoxy-tetraBDEs [6-methoxy-2,2',4,4'- tetraBDE (6-MeO-BDE47) and 2'-methoxy-2,3',4,5'- tetraBDE (2'-MeO-BDE68)] in pike from Lake Bolmen for the years 1967-2000, are presented. All BDE congeners show increasing trends up to the mid-1980s (Sigma5PBDE from 60 to 1600 pg/g wet weight in 1989, i.e. a more than 25-fold increase), and then decrease or level off. The decreasing trends of PBDEs after the 1980s were considerably slower in the present study than was found in a study of an environmental matrix from the Baltic Proper covering the same time period. This difference suggests local sources near Lake Bolmen. The MeO-BDEs show initially decreasing concentrations, which for 6-MeO-BDE47 continues until the early 1990s. The concentrations of 6-MeO-BDE47 in herring from five locations along the Swedish coast increased from south to north in the Baltic Sea. No correlation between the concentrations of the BDE congeners and the MeO-BDEs was observed, indicating sources other than PBDEs for these compounds. The presence of MeO-BDEs in fish from lakes with different characteristics suggests a natural production not favoured by eutrophication, or dependent on sampling season and geographical location.

Reproductive toxicity in mink (Mustela vison) chronically exposed to environmentally relevant polychlorinated biphenyl concentrations.

Female mink were exposed to a technical polychlorinated biphenyl (PCB) preparation (Clophen A50 [A50]; 0.1 or 0.3 mg/animal/d), one fraction of A50 containing the non- and mono-ortho-chlorinated congeners (0-1-ortho-chlorobiphenyls [CBs]), another fraction of A50 containing the congeners with two to four ortho-chlorines (2-4-ortho-CBs), or an organic extract from Baltic gray seal blubber. The animals were exposed for 18 months, including two reproduction seasons. Among the animals given the highest dose of A50, the whelping frequency was reduced in the second reproductive season, and all kits died within 24 h of birth. Reproduction was also impaired by the lower dose of A50. Daily exposure to the 0-1-ortho-CBs separated from 0.3 mg A50 severely reduced kit survival. Reproduction was not significantly impaired by daily exposure to the 2-4-ortho-CBs separated from 0.3 mg A50 or by exposure to the blubber extract. We conclude that the reproductive toxicity in chronically PCB-exposed mink is caused by the aryl hydrocarbon (Ah) receptor agonists. The lowest-observed-effect level for reproductive impairment was 2.4 ng 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) equivalents (TEQs) per kilogram body weight and day (22 pg TEQs/g feed). Ethoxyresorufin-O-dealkylase (EROD) was strongly induced by the 0-1-ortho-CBs and pentoxyresorufin-O-dealkylase by the 2-4-ortho-CBs. High EROD activity was correlated with low kit production, and consequently EROD may serve as a marker for reproductive toxicity by Ah receptor agonists in mink.

Extraction and cleanup methods for analysis of phenolic and neutral organohalogens in plasma.

A method for the analysis of potential endocrine-disrupting compounds, such as phenolic halogenated compounds (e.g., chlorinated and brominated phenols) and hydroxylated PCBs, in blood plasma is presented. Neutral halogenated compounds, specifically brominated diphenyl ethers and PCBs, are also included in the evaluation. An efficient denaturation and extraction step is described, and three methods for lipid removal are evaluated. The latter includes a nondestructive method based on high-resolution gel permeation chromatography (HR-GPC), a newly developed silica gel/sulfuric acid column, and lipid removal by sulfuric acid treatment. Recoveries, based on gas chromatography with an electron capture detector (GC-ECD), were between 70 and 90% for most of the studied compounds. The recoveries of phenolic compounds were generally slightly lower than those of the neutral compounds. The sulfuric acid treatment and silica gel/sulfuric acid column gave the highest yields for acid stable compounds, although a few target compounds were lost during that treatment and all compounds were recovered with the HR-GPC method.

Polychlorinated biphenyls and some pesticides in perch (Perca fluviatilis) from inland waters of Latvia.

Polychlorinated biphenyls (PCBs), DDT-related substances, hexachlorocyclohexane (HCH) isomers and hexachlorobenzene (HCB) were analysed in perch (Perca fluviatilis) from Latvian lakes and rivers. DDE is present in the highest concentrations in all samples; 62-170 ng/g lipid weight in perch from rural areas and 460 ng/g in perch from the Riga area. Individual dominating PCB congeners were in the range 16-45 ng/g and 200-210 ng/g, respectively. The degree of contamination of rural areas in Latvia of these organohalogen substances is in the same range as in background areas in Sweden. Riga, the major urban area in Latvia, is shown to be more polluted with PCBs than other areas in Latvia.

The Swedish Environmental Specimen Bank--application in trend monitoring of mercury and some organohalogenated compounds.

The Environmental Specimen Bank (ESB) at the Swedish Museum of Natural History, Stockholm, constitutes a base for ecotoxicological research as well as for spatial and trend monitoring of contaminants in Swedish fauna. Since the 1960s, tissue samples from more than 150000 organisms have been collected from different groups of animals, habitats and types of landscape. Samples from the ESB have been utilized for retrospective studies of trace elements, organohalogenated compounds and radionuclides. Among many matrices utilized, eggs of guillemot (Uria aalge) have proven to be an appropriate matrix for assessment of the contamination of the Baltic Sea. Results from time trend studies based on this material showing trends in concentrations of DDT, PCB, PCDD/F, and mercury are presented in this paper.

Distribution of Polychlorinated Naphthalene Congeners inEnvironmental and Source-Related Samples

Polychlorinated naphthalene (CN) congener profiles inenvironmental and source related samples were compared graphically and byprincipal component analysis. Samples investigated included biological,sediment, water, and air samples, technical polychlorinated biphenyl (PCB)and polychlorinated naphthalene (PCN) formulations, as well as municipalwaste incineration (MWI) fly ash and graphite electrode sludge. Biologicalsamples showed a preferential enrichment of planar, 1,3,5,7-substitutedtetra-, penta-, and hexachlorinated congeners and most of these samplesshowed profiles that displayed some similarity to those found in thetechnical PCB formulations. Sediment samples representing diffuse pollution,i.e., sediment samples from remote sites, showed an elevatedabundance of the planar hexa- and heptaCN congeners(1,2,3,4,6,7-/1,2,3,5,6,7- and 1,2,3,4,5,6,7-). The CN congener profile foundin these sediment samples and the two air samples were more similar to thetechnical PCB formulations than to the investigated MWI and graphite sludgesamples. Samples from three PCB contaminated lakes displayed similar congenerprofiles as Aroclor 1242, 1254 and Clophen A40. Two sediment samples and apike sample collected from the vicinity of a chloroalkali plant showedprofiles that were closely related to the investigated graphite electrodesludge sample. None of the environmental samples displayed profiles similarto low or medium chlorinated technical PCN (Halowax 1099, 1013, and 1014).

The effect of intraoperative blood loss on serum cefazolin level in patients undergoing instrumented spinal fusion. A prospective, controlled study.

STUDY DESIGN: This study is a prospective, controlled study of the effect of intraoperative and postoperative blood loss during spinal surgery on serum cefazolin level. OBJECTIVES: To determine what effect, if any, intraoperative blood loss has on serum antibiotic levels, and to determine if adjustment of the dose or dose interval is appropriate in operative cases of significant blood loss. SUMMARY OF BACKGROUND DATA: The problem of infection at the operative site after posterior spinal fusion with internal fixation is significant. It commonly has been accepted that blood loss results in a more rapid clearance of antibiotic. METHODS: Nineteen patients scheduled for elective spinal fusion with internal fixation were enrolled in this study. Each patient served as his or her own control. Baseline cefazolin clearance was determined the week before surgery. Cefazolin clearance again was determined intraoperatively. Blood loss was recorded throughout the procedure. RESULTS: The mean blood loss was 650 mL. There was no significant difference between preoperative and intraoperative cefazolin clearance, and there was no correlation between blood loss and cefazolin level. CONCLUSIONS: It is not necessary to give cefazolin at a dosing interval of less than 4 hours with blood losses of up to 1200 mL. This will maintain the antibiotic concentrations well above the minimum inhibitory concentration.

Effect of intraoperative blood loss on the serum level of cefazolin in patients managed with total hip arthroplasty. A prospective, controlled study.

The effect of intraoperative blood loss on serum levels of cefazolin in patients being managed with total hip arthroplasty was studied. Eighteen patients, thirteen men and five women, with a mean age of sixty-five years (range, forty to eighty-five years) were enrolled in the study. Fifteen had a primary total hip arthroplasty and three, a revision. Each patient served as his or her own control. Baseline clearance of cefazolin was determined at a minimum of forty-eight hours before the operation. Each patient received one gram of cefazolin intravenously. Serial serum concentrations were determined from specimens drawn at zero, five, ten, twenty, thirty, sixty, 120, 240, and 300 minutes after administration. Fifteen minutes before the skin incision was made, each patient again received one gram of cefazolin intravenously. Serum samples were collected at the same time-intervals, and the serum levels of cefazolin were determined with use of capillary electrophoresis. Data regarding intraoperative blood loss as well as replacement of fluid and blood were recorded. The administration of the antibiotic, retrieval of the serum samples, and estimation of the blood loss were performed by the same person in the same manner for all patients. The preoperative and intraoperative creatinine clearances (mean and standard deviation), estimated with use of the formula of Cockcroft and Gault, were 62.06 +/- 21.28 and 74.02 +/- 24.75 milliliters per minute, respectively. The amount of intraoperative blood loss averaged 1137 +/- 436 milliliters (range, 675 to 2437 milliliters). The preoperative and intraoperative cefazolin clearances averaged 0.49 +/- 0.21 and 0.52 +/- 0.30 milliliter per minute per kilogram, respectively. During joint replacement, the commonly accepted interval between doses of cefazolin is four hours. In the present study, the serum level of cefazolin at four hours was forty-five micrograms per milliliter. This corresponds to an osseous concentration that well exceeds the minimum inhibitory concentration for Staphylococcus aureus, which is 0.5 microgram per milliliter. This study suggests that, with blood losses of less [corrected] than 2000 milliliters, it is not necessary to administer cefazolin at intraoperative intervals of less than four hours in order to maintain a concentration of antibiotics that is higher than the minimum inhibitory concentration for the most common infecting organisms.

Measurement of lumbar lordosis. Evaluation of intraobserver, interobserver, and technique variability.

STUDY DESIGN: Sixty radiographs were measured on two separate occasions by three physicians using four different techniques to evaluate the reliability and reproducibility of the measurement of lumbar lordosis. OBJECTIVE: To evaluate clinical methods of measuring lumbar lordosis, determining intraobserver and interobserver reliability. SUMMARY OF BACKGROUND DATA: Several different methods are used to measure lumbar lordosis. The reliability and reproducibility of these has not been well studied. METHODS: Sixty lateral full spine radiographs were obtained, labeled, and the lumbar lordosis measured independently by three practitioners who routinely perform these measurements. Four measurement techniques were used. These included measurements from the inferior endplate of T12 to the superior endplate of S1; the superior endplate of L1 to the superior endplate of S1; the inferior endplate of T12 to the inferior endplate of L5; and the superior endplate of L1 to the inferior endplate of L5. The measurements then were repeated after relabeling. RESULTS: Intraobserver reliability coefficients ranged from 0.83 to 0.92, indicating excellent reproducibility. Ninety-two percent of repeat measures were within 10 degrees. High overall and pairwise agreement among the three observers also was present; the interobserver reliability coefficients ranged from 0.81 to 0.92. CONCLUSIONS: The measurement of lumbar lordosis is reproducible and reliable if the technique is specified and one accepts 10 degrees as acceptable variation. Factors that affect the reproducibility of measurement include end vertebra selection (especially with transitional segments) and vertebral endplate architecture.

A walking program for nursing home residents: effects on walk endurance, physical activity, mobility, and quality of life.

OBJECTIVES: To determine the effects of a 12-week walking program on walk endurance capacity, physical activity level, mobility, and quality of life in ambulatory nursing home residents who had been identified as having low physical activity levels and low walk endurance capacities. To determine the effects of 12 versus 22 weeks of walk training on walk endurance capacity, physical activity level, mobility, and quality of life in ambulatory nursing home residents. DESIGN: Experiment 1: Residents of one nursing home campus were assigned to the walking program, and residents of a second campus were assigned to the social visit control group. Outcome measures were taken before and after 12 weeks. Experiment 2: Pretest/posttest with outcome measures taken before and, again, after 12 and 22 weeks of walking. SETTING: Two campuses of the Jewish Homes for the Aging in the Los Angeles area. PARTICIPANTS: Experiment 1: Nineteen of 22 residents in the walking group completed the walking program, and 12 of 15 residents in the control group completed the study. Experiment 2: Thirty of 41 residents (from the two nursing homes) completed the 22-week walking program. INTERVENTION: Experiment 1: The walking program involved each resident walking with research staff at his/her self-selected walking pace, 5 days per week for 12 weeks, for a maximum of 30 minutes per day; while the control group had weekly individual social visits, which lasted 30 minutes, from a research assistant. Experiment 2: All residents, those in both the walking and the control group, were offered the opportunity to complete 22 weeks of walking. MAIN OUTCOME MEASURES: Maximal walk endurance capacity, the resident's maximum walk time performed in a single day of walking (distance and speed also were measured); physical activity level based on time-sampled observations and physical activity monitors; mobility as measured with the Timed-Up-and-Go test, left handgrip strength, and Tinetti's Mobility Assessment; and quality of life as assessed with the Geriatric Depression Scale (a bodily pain scale) and the Dartmouth Primary Care Cooperative Information Project (COOP) physical work chart. RESULTS: Experiment 1: The walking group significantly improved their maximal walk endurance time by 77% and distance by 92%, with no significant change in walk speed; however, the control group showed no significant changes in these variables. There were no significant group by time interactions on measures of physical activity, mobility, and quality of life. Experiment 2: No further significant changes were found from 12 to 22 weeks in walk endurance capacity, physical activity, mobility, or quality of life. CONCLUSION: Twelve weeks of daily walking at a self-selected walking pace by ambulatory nursing home residents produced significant improvements in walk endurance capacity. No other significant changes were noted in physical activity level, mobility, or quality of life in either group after the intervention. Also, there were no side effects, such as increases in falls or cardiovascular complications, due to the walking intervention. Lengthening the walking program to 22 weeks produced no further significant changes in any outcome measures.

Polychlorinated biphenyls, 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p'-DDT) and 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE) in human plasma related to fish consumption.

Fatty fish species, e.g., salmon and herring, in the Baltic Sea have high levels of polychlorinated biphenyls (PCBs) and 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (p,p'-DDT), and its main metabolite: 1,1-dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE). We determined levels of 10 different PCB congeners, including non- and mono-ortho-PCBs, as well as DDT and DDE, in human blood plasma from 37 subjects with varying intake of fish (0-1 750 g/wk) from the Baltic Sea. With respect to all of the PCB congeners we investigated, as well as for DDT and DDE, there were statistically significant associations with fish intake. Thus, fish from the Baltic Sea is a major source of exposure to these compounds in Swedes. Polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) had been determined earlier in 29 of the subjects. The PCB contribution to "dioxin-like" effects among high consumers of fish (calculated as Nordic TCDD equivalents) was almost 80%, whereas that from PCDD and PCDF was only 20%.