Fitness of Isidorella newcombi Following Multi-generational Cu Exposures: Mortality, Cellular Biomarkers and Life History Responses.

The effects of multigenerational Cu exposure on the freshwater gastropod Isidorella newcombi were investigated. Snails were exposed to a range of treatment-specific Cu concentrations in the parental to F2 generations, and a common Cu concentration in the F3 generation. In the parental to F2 generations, some general responses to 3 days Cu exposures included reduced survival and feeding in snails exposed to higher Cu concentrations. This suggested that the snails exposed to the high Cu concentration were experiencing Cu-induced stress that may apply selection pressure. In the F3 generation, when all treatments were exposed to a common Cu concentration, increased survival was correlated with the pre-exposure Cu concentration history. Snails that had been pre-exposed to Cu also displayed reduced stress at a sub-lethal level, indicated by lower lysosomal destabilisation (LD). Mortality and LD responses in the F3 generation were not related to Cu tissue concentrations, indicating increased tolerance and reduced stress were not related to changes in Cu bioaccumulation. Total antioxidant capacity increased in the higher Cu concentration pre-exposure treatments which could be associated with lower Cu-induced stress, however, this is not supported by the oxidative damage marker lipid peroxidation, which also increased. While Cu tissue concentrations and oxidative stress markers were assessed to determine underlying reasons for increased tolerance in snails from a population with a multi-generational exposure history to Cu, the results were not conclusive. Despite this, it was demonstrated through increased survival and reduced LD that Cu tolerance can develop over a short evolutionary time scale.

The Response of the Planorbid Snail Isidorella newcombi to Chronic Copper Exposure Over a 28-Day Period: Linking Mortality, Cellular Biomarkers, and Reproductive Responses.

The native freshwater gastropod Isidorella newcombi attacks the roots of developing rice plants in southern Australia and is controlled using copper sulphate. The apparent tolerance of this species to moderate levels of copper (Cu) exposure led us to investigate its potential usefulness as a biomonitor species. To assess its response to chronic Cu exposure, adult I. newcombi were exposed to 0-120 µg L-1 of Cu for 28 days. Lethal and sublethal responses were investigated. The relationships between subcellular biomarkers and life history traits also were explored. At exposure concentrations of 60 µg L-1 Cu and above, 100% mortality was observed during the 28-day exposure period. In these treatments, there was an exposure concentration dependent decrease in the time that the snails survived. In the surviving snails, there was an exposure concentration-dependent increase in tissue Cu concentration. In the snails exposed to Cu concentrations above 15 µg L-1, no eggs were produced during the final week of copper exposure, indicating that populations would not persist at Cu concentrations above 15 µg L-1. The general stress biomarker lysosomal membrane destabilisation (LD) indicated organisms exposed to 10 µg L-1 Cu and above were experiencing Cu induced stress. This suggests that LD could act as an early warning system for responses at higher levels of biological organisation in I. newcombi exposed to copper.

Metal concentrations in waters, sediments and biota of the far south-east coast of New South Wales, Australia, with an emphasis on Sn, Cu and Zn used as marine antifoulant agents.

Tin, Cu, Zn, Cd, Pb, Ag and Hg concentrations were measured in waters, sediments and three ubiquitous sedentary molluscs: the oyster, Saccostrea glomerata, a rocky intertidal gastropod, Austrocochlea porcata, and a sediment-dwelling gastropod, Batillaria australis, at 12 locations along the far south coast of NSW, Australia, from Batemans Bay to Twofold Bay during 2009. Metal concentrations in water for Sn, Cd, Ag and Hg were below detection limits (< 0.005 µg/L). Measurable water metal concentrations were Cu: 0.01-0.08 µg/L, Zn: 0.005-0.11 µg/L and Pb: 0.005-0.06 µg/L. Mean metal concentration in sediments were Sn < 0.01-2 µg/g, Cu < 0.01-605 µg/g, Zn 23-765 µg/g, Cd < 0.01-0.5 µg/g, Pb < 0.01-0.3 µg/g, Ag < 0.01-0.9 µg/g and Hg < 0.01-2.3 µg/g. Several locations exceeded the Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand (Australian and New Zealand guidelines for fresh and marine water quality 2000) low and high interim sediment quality guidelines' levels for Cu, Zn, Cd and Hg. Some sites had measurable Sn concentrations, but these were all well below the levels of tributyltin known to cause harm to marine animals. Elevated metal concentrations are likely to be from the use of antifoulants on boats, historical mining activities and agriculture in the catchments of estuaries. All molluscs had no measurable concentrations of Sn (< 0.01 µg/g) and low mean Ag (< 0.01-1.5 µg/g) and Hg (< 0.01-0.5 µg/g) concentrations. Mean Cu (24-1516 µg/g), Zn (45-4644 µg/g), Cd (0.05-5µg/g) and Pb (0.05-1.1 µg/g) in oysters were close to background concentrations. Oysters have Cd and Pb concentrations well below the Australian Food Standards Code (2002).] There were no significant correlations between metal concentrations in sediments and in organisms within locations, and no relationship with levels of boating activity and suspected antifouling contamination. Although not pristine, the low levels of metal contamination in sediments and molluscs in comparison with known metal-contaminated areas indicate that this region is not grossly contaminated with metals and suitable for the development of mariculture.].

Factors influencing arsenic concentrations and species in mangrove surface sediments from south-east NSW, Australia.

Arsenic concentrations and speciation of 55 mangrove surface sediment samples from the south-eastern coast of NSW, Australia, have been measured. Arsenic concentrations were in the range 1.6-8.6 µg/g dry mass. All arsenic concentration values were well below 20 µg/g, the ANZEC/ARMCANZ interim sediment quality guideline-low trigger value. The bulk sediment pH was 6.0-7.3 and Eh -80 to -260 mV. The sediments contained variable silt-clay (2-30 % w/w), iron (668-12721 µg/g), manganese (1-115 µg/g), sulphur (70-18400 µg/g) and carbon (5-90 mg/g) concentrations. Arsenic concentrations correlated with silt and clay content, iron and manganese concentrations, indicating silt-clay particles covered and coated with iron and manganese (oxy) hydroxides scavenged arsenic. Arsenic extracted with 0.5 M phosphoric acid (68-95 %) was present only as inorganic arsenic (55-91 %), indicating that other arsenic species such as arsenobetaine derived from marine animal tissues rapidly degrade in sediments. The unextractable arsenic was correlated with increases in organic carbon, iron and manganese content. In conclusion, the cycling of arsenic in mangrove sediments is essentially the cycling of inorganic arsenic and primarily controlled by the redox cycling of carbon, sulphur, iron and manganese.

The use of the marine gastropod, Cellana tramoserica, as a biomonitor of metal contamination in near shore environments.

The use of the marine gastropod, Cellana tramoserica, as a biomonitor of metal exposure was investigated. The factors influencing metal concentrations, such as mass, gender, substrate, shoreline position and temporal variation were examined. Tissue metal concentrations were mostly found to be independent of mass and gender. When metal concentrations were significantly correlated with mass, correlations were low and explained little variability. The underlying substrate and position in the littoral zone had only a small influence on metal concentrations. Variation between individuals, inherent variability due to genetic variability, was the most significant contribution to the overall variation in metal concentrations, resulting in positive skewing of population distributions. The mean metal concentrations varied temporally; metal masses were relatively constant with fluctuations in metal concentrations related to fluctuations in metal body burdens. The populations from a metal-contaminated site had significantly higher tissue Cu, Zn, As and Pb concentrations than the populations from relatively uncontaminated locations. C. tramoserica therefore can be considered to be a net accumulator of metals. A sample number of >10 is required to detect changes of 25 % from the mean concentrations at uncontaminated locations. This species meets the requirements of a suitable biomonitor for metal contaminants in the environment i.e. hardy, sessile, widespread, sufficient tissue mass and a metal accumulator. As the measurement of metal concentrations in C. tramesoria were influenced by substrate and shore position and, sometimes, mass, sites with similar substrates and organisms of similar mass and shoreline position should be chosen for comparison. When comparing metal concentrations in gastropods from different locations, they should be collected over the same period to minimise variability due to mass differences, spawning and other seasonal/temporal effects.

Measurement of inorganic arsenic species in rice after nitric acid extraction by HPLC-ICPMS: verification using XANES.

The measurement of As species in rice is normally accomplished by extraction followed by HPLC-ICPMS analysis. This method, however, has not been comprehensively validated by comparing these speciation results with XANES, which does not require sample extraction, due to the challenge of conducting XANES analysis at very low As concentrations. In this study As speciation data using nitric acid extraction/HPLC-ICPMS and XANES are compared to verify the efficacy of using 2% v/v nitric acid extraction and HPLC-ICPMS to measure inorganic As, DMA, and MA in reference rice materials and common rice varieties obtainable in Australia. Total As and As species (As(III), As(V), DMA, and MA) concentrations measured in 8 reference materials were in agreement with published values. XANES analysis was performed on 5 samples having total As concentrations ranging from 0.198 to 0.335 µg g(-1). XANES results gave similar proportions of total As(III), As(V), and DMA to HPLC-ICPMS. XANES was able to distinguish two forms of As(III): As(III) and As(III)GSH. Total As concentrations in rice samples varied from 0.006 to 0.45 µg g(-1) As (n = 47) with a mean ± std of 0.127 ± 0.112 µg g(-1) As with most As present as inorganic species (63 ± 26%). DMA was found in nearly all the rice samples with the majority of samples containing concentrations below 0.05 µg g(-1) As while MA concentrations were negligible (<0.003 µg g(-1) As). Six rice varieties produced in Australia, China, and Spain all had elevated DMA concentrations (0.170-0.399 µg g(-1) As) that were correlated with total As concentrations (r(2) = 0.7518). In conclusion, comparison of As speciation by HPLC-ICPMS and XANES showed that similar As species were detected indicating the appropriateness of using 2% v/v nitric acid for extraction of rice prior to speciation. Common rice varieties obtainable in Australia generally have low As concentrations with most As present as inorganic As.

Arsenic toxicity in a sediment-dwelling polychaete: detoxification and arsenic metabolism.

The accumulation, subcellular distribution and speciation of arsenic in the polychaete Arenicola marina were investigated under different laboratory exposure conditions representing a range of metal bioavailabilities, to gain an insight into the physiological mechanisms of how A. marina handles bioaccumulated arsenic and to improve our understanding of the potential ecotoxicological significance of bioaccumulated arsenic in this deposit-feeder. The exposure conditions included exposure to sublethal concentrations of dissolved arsenate, exposure to sublethal concentrations of sediment-bound metal mining mixtures, and exposure to lethal concentrations of sediment-bound metal mining mixtures and arsenic- and multiple metal-spiked sediments. The sub-lethal exposures indicate that arsenic bioaccumulated by the deposit-feeding polychaete A. marina is stored in the cytosol as heat stable proteins (~50%) including metallothioneins, possibly as As (III)-thiol complexes. The remaining arsenic is mainly accumulated in the fraction containing cellular debris (~20%), with decreasing proportions accumulated in the metal-rich granules, organelles and heat-sensitive proteins fractions. A biological detoxified metal compartment including heat stable proteins and the fraction containing metal-rich granules is capable of binding arsenic coming into the cells at a constant rate under sublethal arsenic bioavailabilities. The remaining arsenic entering the cell is bound loosely into the cellular debris fraction, which can be subsequently released and diverted to an expanding detoxified pool. Our results suggest that a metal sensitive compartment comprising the cellular debris, enzymes and organelles fractions may be more representative of the toxic effects observed.

Non-attendance at an out-patient otolaryngology and head and neck clinic in New Zealand: impact of coronavirus disease 2019, and demographic, clinical and environmental factors.

BACKGROUND: Fear of contracting coronavirus disease 2019 may be the latest addition to the barriers to clinic attendance. This study aimed to examine the impact of coronavirus disease 2019 and other variables on non-attendance rate at an out-patient clinic. METHODS: Clinic attendance at the Department of Otolaryngology and Head and Neck Surgery, Waikato Hospital, New Zealand, was assessed. For each appointment, the impact of coronavirus disease 2019 and other variables on non-attendance rate were analysed. RESULTS: In total, 1963 appointments were scheduled, with 194 non-attendances (9.9 per cent). Patients who had their appointments confirmed beforehand were 10.0 times more likely to attend their appointment. Sex, socioeconomic status, ethnicity and age were found to impact non-attendance rate. CONCLUSION: In New Zealand, coronavirus disease 2019 does not appear to be a barrier to out-patient clinic appointment attendance. The patient's age, sex, ethnicity, socioeconomic status and prior appointment confirmation were found to influence clinic attendance.

Timing of cholecystectomy for acute cholecystitis impacts surgical morbidity and mortality: an NSQIP database analysis.

The aim of this study is to identify the optimal timing for cholecystectomy for acute cholecystitis. Patients undergoing cholecystectomy for acute cholecystitis from the National Surgery Quality Improvement Program database between 2014 and 2016 were included. The patients were divided into 4 groups, those who underwent surgery at days 0, 1, 2, or 3+ days. The primary outcome was short-term surgical morbidity and mortality. A total of 21,392 patients were included. After adjusting for confounders, compared to day 0 patients, those who underwent surgery at day 1 and day 2 had lower composite morbidity rate, while day 3+ patients had significantly higher bleeding and mortality rate. Subgroup analysis shows this trend to be more significant in the elderly and in diabetic patients who were delayed. Delay in cholecystectomy for over 72 h from admission is associated with statistically significant increase in bleeding and mortality.

The accumulation of Zn, Se, Cd, and Pb and physiological condition of Anadara trapezia transplanted to a contamination gradient in Lake Macquarie, New South Wales, Australia.

The benthic bivalve, Anadara trapezia, was collected from a 'clean' reference site and transplanted along a suspected trace metal contamination gradient in Lake Macquarie, NSW. At monthly intervals, Zn, Se, Cd and Pb concentrations were measured in the surficial sediments and whole tissues of the cockle as well as their physiological condition (Scope for Growth). Zinc, Cd and Pb concentrations in sediments decreased together, southward, with the highest concentrations in the Cockle Bay area, suggesting that this is the main source of contamination. Zinc, Cd and Pb concentrations were near or above [ANZECC/ARMCANZ, 2000. National water quality management strategy paper 4. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand. pp. 3.5.-1-3.5-10] sediment quality guidelines at Cockle Creek, Warners Bay and Koorooa Bay. Significant differences in trace metal concentrations could not be attributed to grain size or Fe concentration differences. Se concentrations were highest in fine grain Fe rich sediments of Whiteheads Lagoon, and likely to be associated with power generation operations. Trace metal concentrations did not vary significantly over time. Zinc, Cd and Pb concentrations in the tissues of A. trapezia followed a similar pattern to that of sediments. Zinc and Pb concentrations in cockles and sediments were highly correlated, indicating significant exposure-dose relationships. Selenium concentrations in the tissues of A. trapezia were higher after transplantation to the lake, however, Se concentrations were similar in all transplanted cockles, indicating that Se in contaminated sediments is not the major source of Se to organisms. There was a decline in the physiological condition of A. trapezia transplanted to Lake Macquarie after a 90-day-period with marked differences in clearance rates and respiration rates at some locations and absorption efficiencies at all locations. The mean Scope for Growth value at the most contaminated location, Cockle Bay, was markedly lower than at other locations. A significant Zn exposure-dose response relationship indicates that Zn bioaccumulation is occurring in response to sediment contamination. A significant Cd exposure-response relationship indicates that Cd may be influencing the health of cockles. Significant Pb exposure-dose, exposure-response and dose-response relationships indicate that Pb probably is affecting the health of cockles in Lake Macquarie. Therefore, Zn, Cd and Pb concentrations in sediments are likely to be affecting the health of cockles in Lake Macquarie.

Circumferential rotator cuff repair with the n+4 portal, subclavian portal, and high posteromedial portal.

Passing suture during a rotator cuff repair requires proper orientation and purchase of the rotator cuff tendon. Our technique uses a new portal to improve access to the supraspinatus and infraspinatus and uses additional portals for a circumferential repair of the tear, thereby restoring the footprint. Using a penetrating suture passer through the anterior, posterior, and superomedial portals allows 270° of coverage. The lateral anchors complete the circumferential repair. Sutures from the medial anchors are passed in a retrograde fashion using 3 small incisions with no cannula. A spinal needle is used to localize the orientation of each portal. The N+4 portal is the workhorse portal, allowing access to the supraspinatus and infraspinatus. The suture retriever enters the trapezius 5 cm from the medial border of the acromion and 1 cm anterior to the spine of the scapula. It enters the subacromial space on top of the supraspinatus. This provides protection to the suprascapular nerve in the supraspinatus fossa. The cuff is lifted with a grasper to allow perpendicular passage of suture. The suture is retrieved for tying. The tissue purchase and location of suture placement help restore the footprint of the supraspinatus and infraspinatus. Additional sutures are passed anteriorly through the subclavian portal and posteriorly through the high posteromedial portal. The repair is completed with lateral-row anchors as needed.

Plasmid analysis of 26 staphylococcal species by a rapid microscale technique.

OBJECTIVE: Evaluate a plasmid typing technique for a diverse group of staphylococci. DESIGN: In vitro testing on known isolates. SETTING: University hospital. INTERVENTION: The plasmid content of 195 isolates representing 26 staphylococcal species was analyzed by agarose gel electrophoresis following lysostaphin-alkaline-SDS lysis, with and without acetone treatment. RESULTS: Isolates yielded plasmid profiles with 0 to 7 extra-chromosomal bands (median, 1; 1.5); 171 (88%) had a profile with at least 1 band. Species with more than one isolate available for testing showed considerable diversity of plasmid profiles, except for Staphylococcus haemolyticus. CONCLUSIONS: The ease of the procedure and the diversity of plasmid profiles within each species examined suggests that plasmid profiling is an accessible and useful epidemiologic tool applicable to most staphylococcal species by epidemiologic units or clinical laboratories.

Naturally-occurring, osmo-remedial variants of Escherichia coli.

Two clones of Escherichia coli O27:K1:H31 and O2:H7, isolated from patients with urinary tract infection or bacteraemia, failed to grow in a synthetic minimal medium (MM) of low osmolality. They were considered to be osmo-remedial because they grew well when sufficient amounts of NaCl, mannitol or sucrose were added to raise the osmolality of the medium to > 300 mOsm/kg. The defect could also be corrected by nicotinamide or its precursors quinolinic and aspartic acids. Each clone had a unique DNA restriction enzyme profile, fimbriae and antibiotic susceptibility patterns. The osmo-remedial variants were unstable and underwent phenotypic modulation to form mixtures with osmo-tolerant forms when grown in MM. They tended to form satellites of small colonies around large colonies of osmo-tolerant cells on MM agar plates. The penicillin method of Davis was used to separate the two forms. Nicotinamide induced the expression of ompF when the osmo-remedial strains were grown under conditions of low osmolality. It is possible that the variants are defective in the synthesis of membrane-derived oligosaccharides or outer-membrane proteins, but this has yet to be determined.

Personality and psychopathology: a historical perspective.

The possible links between personality psychology and psychopathology are examined with the goal of understanding the constraints that set boundaries to the possible contributions of one to the other. The reciprocal nature of these contributions is described. The historical survey looks at the early concepts of the humors and temperament, at the concept of a general vulnerability to psychosis and deviance--represented by the 19th-century concept of degeneracy--and at later typologies arising from the work of Eysenck, Freud, Kretschmer, Pavlov, and Sheldon. The impact of current developments in neuropsychology and in cognitive psychology is discussed.

Determination of total arsenic by use of a zinc-column arsine generator.

A method for the measurement of total arsenic in extracts of environmental materials is described. Arsenic is reduced to arsine with a zinc reductor column, the evolved arsine is decomposed in a heated carbon-tube furnace, and arsenic determined by measurement of its atomic-absorption at 193.7 nm. The detection limit is 0.002 mug/ml and the coefficient of variation is 1.4% at 0.01 mug/ml.

Fluorimetric determination of selenium in some marine materials after digestion with nitric and perchloric acids and co-precipitation of selenium with lanthanum hydroxide.

A modified spectrofluorimetric method for the determination of selenium in some marine tissues is described. Selenium is isolated from potentially interfering elements by co-precipitation, then a piazselenol is formed between selenium and 2.3-diaminonaphthalene at pH 1.0 and extracted into cyclohexane. The selenium is determined fluorometrically (lambda(ex), 377 nm; lambda(em), 519 nm) in the extract. The detection limit is 3.6 rig (6 times the standard deviation of the blank) and the coefficient of variation is 4% at the 10-ng level.

A decomposition procedure for the determination of arsenic in marine samples.

The use of wet and dry ashing procedures to decompose marine biological tissues and to degrade organoarsenic compounds to inorganic arsenic for analysis by zinc-column arsine generation and atomic-absorption spectrophotometry was investigated. Wet ashing with nitric, sulphuric and perchloric acids (10:2:3 v/v) released the largest percentage of arsenic from fish tissue and quantitatively degraded methylated and other organoarsenic compounds to inorganic arsenic. The arsenic concentrations found when standard reference materials were ashed with this acid mixture were in agreement with the certified values.

Natural variation of copper, zinc, cadmium and selenium concentrations in Bembicium nanum and their potential use as a biomonitor of trace metals.

Copper, zinc, cadmium and selenium were measured in the gastropod mollusc Bembicium nanum at two uncontaminated locations, Jervis Bay and Rosedale, NSW, to determine natural variability of metals associated with gender, mass, shore position and temporal variability. Trace metals were also measured in B. nanum at three industrialised locations to determine the accumulation of trace metals in contaminated environments.Copper, zinc, cadmium and selenium concentrations were not significantly different between male and female B. nanum. No significant relationships were found between zinc, cadmium and selenium concentrations and mass. There was a significant relationship between copper concentration and mass but only 19% of the variation was explained by mass. Generally inherent variability within samples had a greater influence than gender or variations in mass on trace metal concentrations. No trend was found in cadmium and selenium concentrations with variation in shoreline position. Copper and zinc concentrations increased further away from the low tide mark, with a decrease in metal concentrations at the furthest site from the water. Variability in metal concentrations is attributable to variations in food source, food availability and different immersion times.Copper, zinc, cadmium and selenium concentrations varied over a 12-month period. Copper, cadmium and selenium were taken up and lost over time, as metal body burden followed the same trend as metal concentrations. Zinc concentrations were influenced by mass. Copper and cadmium concentrations fluctuated throughout the 12-month period but with no clear seasonal trends. Selenium concentrations peaked in spring (October), with concentrations remaining uniform over the other months. These differences in mean concentrations between months were most likely due to inherent trace metal variability associated with differences in food availability and changes in metabolic rates associated with changes in temperature during the study period. Measurement of trace metals in B. nanum at contaminated sites showed that B. nanum accumulates metals in response to contamination.B. nanum meets most of the requirements to be a biomonitor of trace metal contamination as they are abundant, sedentary, easy to identify, provide sufficient tissue for analysis, tolerate high concentrations of pollutants and they accumulate trace metals in response to contamination. However, as trace metal concentration can vary with mass, shoreline position and temporally, care must be taken to collect individual organisms with similar mass from similar shoreline positions and times.

Buprenorphine added to the local anesthetic for axillary brachial plexus block prolongs postoperative analgesia.

BACKGROUND AND OBJECTIVES: Buprenorphine added to local anesthetic solutions for supraclavicular block was found to triple postoperative analgesia duration in a previous study when compared with local anesthetic block alone. That study, however, did not control for potentially confounding factors, such as the possibility that buprenorphine was affecting analgesia through intramuscular absorption or via a spinal mechanism. To specifically delineate the role of buprenorphine in peripherally mediated opioid analgesia, the present study controlled for these 2 factors. METHODS: Sixty American Society of Anesthesiologists (ASA) P.S. I and II, consenting adults for upper extremity surgery, were prospectively assigned randomly in double-blind fashion to 1 of 3 groups. Group I received local anesthetic (1% mepivacaine, 0.2% tetracaine, epinephrine 1:200,000), 40 mL, plus buprenorphine, 0.3 mg, for axillary block, and intramuscular (IM) saline. Group II received local anesthetic-only axillary block, and IM buprenorphine 0.3 mg. Group III received local anesthetic-only axillary block and IM saline. Postoperative pain onset and intensity were compared, as was analgesic medication use. RESULTS: The mean duration of postoperative analgesia was 22.3 hours in Group I; 12.5 hours in group II, and 6.6 hours in group III. Differences between groups I and II were statistically significant (P =.0012). Differences both between groups I and III and II and III were also statistically significant (P <.001). CONCLUSIONS: Buprenorphine-local anesthetic axillary perivascular brachial plexus block provided postoperative analgesia lasting 3 times longer than local anesthetic block alone and twice as long as buprenorphine given by IM injection plus local anesthetic-only block. This supports the concept of peripherally mediated opioid analgesia by buprenorphine.

Polycyclic aromatic hydrocarbons in nearshore marine sediments of Australia.

The occurrence and fate of polycyclic aromatic hydrocarbons (PAH) in nearshore marine sediments of Australia is discussed. Available information indicates that PAH are accumulating in the sediments and organisms of estuaries and harbours with both highly urbanized/industrialized and non-urban catchments. PAH levels in polluted sediments are similar to those of grossly polluted areas of Japan, North America and Europe, however PAH sources cannot be identified from the information available. PAH appear to persist in reducing environments, while in relatively pristine environments that have been previously exposed to PAH, conditions are probably favourable for the aerobic degradation of PAH by microorganisms.