Seasonal availability and sensitivity of two field-collected mayflies for the development of a standardized toxicity test.

Ecologically relevant toxicity tests may provide the best protection of sensitive aquatic fauna, but without established culturing or test methodology for such organisms, results may be unreliable and difficult to repeat. Further, field-collected organisms may not be feasible for routine testing purposes, as often required for permitted discharges. This study examined the feasibility of testing two field-collected mayflies, Isonychia bicolor and Maccaffertium spp., over a 1-year period. Seasonal comparisons of availability indicated I. bicolor and Maccaffertium spp. were most abundant during the winter months, resulting in 31 and 49 % of total organisms collected in 2009, while summer was the most difficult time to collect either species. Initial testing in January 2009 resulted in the highest no observable effect concentration (NOEC) values for survivorship (8 g NaCl for I. bicolor and 4 and 8 g NaCl/L for Maccaffertium spp.) when tested at 9 °C. Subsequent tests conducted at 20-23 °C resulted in 7-day NOEC values substantially lower (mean = 1.44 and 1.59 g NaCl/L). Geometric means of exuviae indicated a dose-dependent response for I. bicolor exposed to NaCl, while no dose-dependent response was observed for Maccaffertium spp. with average number of molts varying from 4.93 in the 0.5 g NaCl/L concentration to 3.80 for control organisms followed by 2.24 (1 g NaCl/L). Averages again increased to 3.09 in the 2 g NaCl/L concentration, but declined in the highest concentrations (4-10 g NaCl/L). Based on the results of this feasibility study, field-collected mayflies appear to be too unpredictable in test responses, and therefore, such tests would be unreliable as stand-alone indicators of effluent toxicity.

Influence of a high-fat meal on the absorption of morphine from oral solutions.

The influence of a high-fat meal on blood morphine concentrations after the administration of a morphine solution (50 mg dose) was studied in 12 patients with chronic pain. The oral morphine dose was administered in a total volume of 200 ml to patients either immediately after food intake or while in the fasting state. There was a 34% increase in the area under the curve (AUC) when morphine was administered immediately after food when compared with the fasting state (p less than 0.02). However, there was no significant difference between the maximum blood morphine concentration (Cmax) or the time to maximum concentration (tmax) between the two treatment regimens. The shape of the blood morphine concentration-time curve was consistently altered in the fed patients compared with patients who were in the fasting state, inasmuch as the blood morphine concentrations were maintained at a higher level from 240 to 600 minutes after the dose when the morphine was administered with food (p less than 0.02). It is suggested that morphine concentrations are maintained at higher levels, possibly resulting in more prolonged pain relief, when morphine is administered with food compared with the same dose administered to patients who are in the fasting state.

Epidural mass associated with lack of efficacy of epidural morphine and undetectable CSF morphine concentrations.

A case is presented in which epidurally administered morphine failed to provide the expected extent and duration of pain relief. The patient had severe back pain in the upper lumbar and low thoracic regions and epigastric pain which was presumed to be caused by widespread metastatic deposits in the vertebral column from a prostatic carcinoma. The lack of clinical effect of epidural morphine was shown to be related to the unexpected presence of an epidural mass which was located below the dermatomal region for the patient's pain. Myelography and a CT scan indicated that the mass effectively compressed the subarachnoid space, thereby preventing the rostral spread of morphine in the cerebrospinal fluid (CSF) following lumbar epidural administration, resulting in inadequate pain relief.

Leakage of fluid administered epidurally to rats into subcutaneous tissue.

Epidural catheters were implanted in rats under halothane/nitrous oxide anaesthesia. Contrast medium (Iopamidol) was injected via the catheter under fluoroscopic control 24-48 h after implantation. In 15 of 20 rats contrast could be seen leaking out of the epidural space, usually after only 25 microliters was administered. Leakage was associated with diminished antinociceptive response to morphine administered via the catheter. Both leakage and decreased response to morphine could be largely prevented by applying a drop of Supa-Glue over the site of entry of the catheter to the epidural space at the time of catheter implantation. Investigators using epidurally cannulated rats should document that leakage does not occur or discard results from rats showing evidence of leakage.

The 1996 Leicestershire Community Stroke & Ethnicity Study: differences and similarities between South Asian and white strokes.

OBJECTIVE: To estimate the number of strokes in Leicestershire and investigate possible differences between South Asian and white patients. DESIGN: Prospective incidence sample survey. SETTING: Leicestershire. PARTICIPANTS: Acute stroke cases occurring in registered populations of 12 'high Asian' and 11 'low Asian' general practices. RESULTS: The age-specific incidence rates of stroke in Leicestershire were similar to those of the Oxford Community Stroke Project. South Asian patients were less likely to be living alone at home before their stroke and they tended to be younger than whites. However, only 12% of South Asian patients with a stroke were not admitted to hospital within 7 days of their stroke compared to 23% of white patients (chi2 = 3.24, d.f. = 1, P = 0.07). Only 21% of South Asian patients died within 28 days of their stroke compared to 33% of white patients (age-adjusted odds ratio = 0.37; 95% CI: 0.14-0.97). CONCLUSIONS: Overlapping case-finding was crucial to finding all 'possible' strokes and this required close collaborative working between general practices, community health services, hospitals and the health authority. Relatively fewer South Asian patients were managed in the community in the first 7 days. Interestingly, South Asian patients were less likely than white patients to die within 28 days. This is an area worthy of further research.

The use of temporary atrial electrodes to improve diagnostic capabilities with Holter monitoring after cardiac surgery.

The use of temporary atrial electrodes implanted during cardiac surgery has been advocated for diagnosis and treatment of cardiac arrhythmias in the postoperative period. We have adapted this technique to allow continuous ambulatory electrocardiographic (Holter) recording of atrial activity in patients after coronary artery surgery. The electrodes of one of the two leads of the Holter recorder were attached as a surface electrocardiographic lead, while the electrodes of the other were each attached to one of the two implanted atrial wires. The Holter record was then obtained in the usual way. A satisfactory recording of the atrial electrocardiogram and the simultaneous surface electrocardiogram was obtained in all 6 patients and resulted in improved diagnostic capabilities, specifically in differentiating supraventricular and ventricular arrhythmia. As has proven to be true in the post-myocardial infarction setting, arrhythmias that were not noted clinically despite continuous electrocardiographic monitoring were demonstrated on Holter records.

Acute toxicological effects of ingested tooth whiteners in female rats.

Tooth whiteners are considered as cosmetic agents to be used for bleaching teeth. Since tooth whitener may be swallowed during the whitening procedure, studies were conducted to determine whether ingestion of tooth whitener containing carbamide peroxide resulted in toxic effects. Adult female rats were used, and vaginal smears were examined daily to determine whether the animals were ovulating. Following an overnight fast, a single bolus of a commercial tooth whitener (5 g of tooth whitener/kg fasting body weight) was administered by gavage. Control rats received de-ionized water. After 2 h, mean respirations per min of animals receiving the tooth whitener Quik Start (contains 35% carbamide peroxide) decreased from 169 to 55, and body temperature decreased from 38.4 to 34 degrees C. Other distress signs included: labored breathing, loss of righting reflex, partial eye closure, bloody urine, and incontinence. Three of 22 animals (3/22) died within 48 h, of gastric hemorrhaging. Eight/10 rats stopped ovulating. At necropsy 2 weeks post-dosing, 10/19 animals had grossly bloated stomachs, and mucosal necrosis was observed histologically in 3. Animals receiving White & Brite or Nu-Smile (containing 10 or 15% carbamide peroxide, respectively) exhibited similar but milder symptoms. The data indicate that ingestion of large doses of commercial preparations of tooth whiteners may be acutely toxic, sometimes fatal, to female laboratory rats.

The reproducibility of bioavailability of oral morphine from solution under fed and fasted conditions.

The reproducibility in bioavailability of orally administered morphine (as a solution) under fed and fasted conditions was studied in 5 patients with chronic pain on three occasions over 1 yr (0, 6, and 12 mo). During each study period (i.e.. 0, 6, and 12 mo), patients received the 50 mg oral dose both in the fasted state (10 hr since food) and immediately after a high fat content breakfast, in randomly determined sequence. Frequent blood samples were collected for 10 hr after the dose. There was no significant difference in the maximum blood morphine concentration (Cmax) or the time to Cmax among the three study periods or between the fed and fasted states. Bioavailability, as assessed by log(AUC), was significantly greater in the fed compared to the fasted state (P less than .01) but did not differ over the three study periods (Two-factor analysis of variance). Intrapatient variability contributed 32% and 54% to total variation in log(AUC) under fed and fasted conditions, respectively.

Bromsulphthalein retention test and gamma-glutamyl transpeptidase activity in the investigation of liver disease.

The usefulness of serum gamma-glutamyl transpeptidase activity (gammaGT) was studied in 39 patients on whom a bromsulphthalein retention test (BSP) was performed. In most patients, the potentially hazardous BSP test did not give any further evidence of hepatic disease over conventional hepatic function tests and the gammaGT.

Pelvic floor physiology.

Pelvic floor physiology is poorly understood. The funnel shape of the pelvic floor and anal canal is uniquely developed to provide discriminatory continence of gas, liquid, and solid. Proximally, the pelvic floor consists of the pubococcygeus and iliococcygeus muscles. Distally, the anal canal is surrounded by the internal and external sphincter muscles. The anorectal ring is situated between the proximal pelvic floor and the distal anal canal. It is the site of the puborectalis muscle, which is anatomically, neurologically, and functionally merged with the deep portion of the external sphincter muscle. It is at this site that unique forces act to create both a flutter valve and the anorectal angle with the flap valve. Extrinsic pressures at this level reinforce both the flap valve and the flutter valve. Intrinsic pressures are generated by all of the surrounding muscles to produce a high-pressure zone. These factors are critical, but many other factors, such as rectal capacity, compliance, colonic transit, motility, and sensory mechanisms, also interact in a complex way to provide normal continence and defecation. Not surprisingly, no single test allows a complete assessment of the interactions of all these factors. Nevertheless, analysis of components thought to be important in pelvic floor physiology has contributed significantly to the understanding of normal as well as abnormal physiology. Although clinical evaluation continues to be the cornerstone of the diagnosis of pelvic floor disorders, anorectal physiological testing has contributed significantly to our understanding of the dynamics of the pelvic floor. With the refinement of existing techniques and the addition of new investigative tools, it is anticipated that knowledge of pelvic floor physiology will continue to grow.

Persistent atrial activity during cardioplegic arrest: suppression by verapamil.

Postoperative supraventricular tachyarrhythmia may occur more often in patients with persistent atrial activity during hyperkalemic hypothermic cardioplegic arrest. Cannulation of both venae cavae with simultaneous right atrial intra-cavitary cooling reduces atrial activity but is cumbersome. To evaluate pharmacologically-induced atrial arrest using verapamil, bipolar ventricular and right atrial electrograms were recorded in 12 dogs during one hour of hyperkalemic hypothermic cardioplegic arrest and cardiopulmonary bypass using single caval cannula. Group I (n = 6) received hyperkalemic hypothermic cardioplegic solution (4 degrees C) (20 mEq/1 K+) with verapamil (1 mg/L) by intermittent intra-aortic infusion during systemic hypothermia (28 degrees C). Group II (n = 6) received hyperkalemic hypothermic cardioplegia without verapamil. The percentage of time atrial activity was present (greater than 10 beats/min) in Group I, was significantly less than in Group II. Similarly the total number of atrial beats in Group I was less than in Group II. Recovery of normal sinus rhythm during reperfusion was prolonged in Group I in comparison to Group II. Verapamil induces significant and persistent atrial suppression during hyperkalemic hypothermic cardioplegic arrest but prolongs recovery of normal sinus rhythm during reperfusion. It remains to be established clinically whether verapamil-induced atrial suppression is associated with less postoperative supraventricular tachyarrhythmia. The potential disadvantage of prolonged sinus node recovery time must also be assessed.

Review of physical therapy alternatives for reducing muscle contracture.

Passive stretching is a technique frequently used to treat muscle contractures; however, because it can activate the stretch reflex and has little carry-over, it may not be as effective as other modes. Four approaches to treating muscle contracture are described: 1) activation or strengthening of the weak oppnent, 2) local inhibiton of the contractdd muscle, 3) general inhibition of hypertonus, and 4) passive lengthening. Specific examples of techniques, their rationales, and suggestions for use of each are discussed.

Barriers to enrollment in a state child health insurance program.

OBJECTIVE: To identify barriers to enrollment into Colorado's Child Health Insurance Plan (CHP+) for non-Hispanic (NH), Hispanic (H), and uninsured families. DESIGN: Telephone survey of 1) random samples of families who requested an application but did not complete it (N = 273 NH, N = 159 H) and 2) families with uninsured children identified by random-digit-dial statewide surveys (N = 165). RESULTS: Major reasons for not enrolling included 1) got other insurance (NH 16.5%; H 27.2% P <.01), 2) thought household income was too high to qualify (NH 21.0%; H 11.9% P =.01), and 3) paperwork (NH 13.4%; H 14.7%, P = NS). Of those who thought their income was too high (N = 76, 17.6%), 58.5% appeared eligible based on reported income. Of uninsured families, only 41.7% had heard of CHP+. Of those who had never applied, major remediable reasons included not knowing enough about the program (20.9%) and thinking household income was too high (9.3%). CONCLUSIONS: Effective marketing and education to increase awareness of CHP+ and ensure understanding of eligibility are critical to the success of the program.

Tolerance of the Asiatic clam Corbicula spp. to lethal level of toxic stressors-a review.

Studies assessing the tolerance of the Asiatic clam, Corbicula spp., to a variety of chemical, environmental, and physical stressors are summarised and reviewed. A majority of the studies were conducted (1) in the laboratory, (2) with juvenile and adult stages and (3) with only one stressor per treatment. Trends in the data demonstrate that (1) equivalent median lethal concentrations were generated in studies using both static and flow-through techniques; (2) substantial increases in the levels of mortality among treated clams were obtained by extending exposure durations; (3) incorporation of recovery periods into experimental designs permitted the development of latent mortalities among treated clams; (4) tolerance among larvae was stage dependent while tolerance among adults was not; (5) higher levels of mortality were obtained when tests were conducted at higher temperatures; and (6) testing in the presence of substrate resulted in a decrease in the levels of mortality among treated clams. The implications of these findings are discussed in relation to efforts to mitigate the fouling effects of Asiatic clams in industrial cooling water systems by exposure to toxic chemicals.

Reduction in organic effluent static acute toxicity to fathead minnows by various aeration techniques.

This study compared results of no aeration, intermittent aeration, and constant aeration strategies in determining the static acute (48-h) toxicity of phenolic-based effluents to adult fathead minnows (Pimephales promelas). Toxicity was greatest in no aeration tests followed by intermittent aeration and constant aeration. Two factors were considered responsible for the observed patterns of toxicity. First, in side-by-side tests of no versus intermittent aeration and intermittent versus constant aeration, toxicity reductions were directly attributed to maintenance of dissolved oxygen above 5.0 mg litre(-1) in aerated containers. Secondly, toxicity was reduced when treatment system temperatures were warmest, probably due to increased microbial activity and volatilisation during late spring to early autumn (temperatures > 16 degrees C). Effluent was slightly more toxic on- than off-site, presumably due to degradation of phenolic compounds during transport and set-up at the off-site laboratory (approximately 4.5 h). Gill tissue ultrastructure and histopathology were used to determine the extent of effluent-induced damage and the recovery of minnows to short (6-h) effluent exposures. After a 48-h exposure to the approximate LC(50) level, gill tissue lamellae were characteristically desquamated with epithelium lifting from the basement membrane. Gill tissue was similarly damaged after a 6-h exposure to 100% effluent and had recovered to pre-exposure conditions after 42 h in clean water. Aeration strategies in these studies demonstrated potential air-stripping of volatile compounds, although stress to test organisms from low dissolved oxygen was relieved.

Bioaccumulation of butyltins in Dreissena polymorpha at a confined placement facility in Buffalo, New York.

This study involves a site characterization followed by biomonitoring with the zebra mussel, Dreissena polymorpha, at the Times Beach confined placement facility (CPF), located in Buffalo, NY. The contaminant of interest was tributyltin (TBT) and the degradation products dibutyltin (DBT) and monobutyltin (MBT). At study initiation (Day 0) TBT levels in the baseline mussels were 5.86 +/- 0.43 ng Sn/g, DBT levels were 2.25 +/- 0.37 ng Sn/g. No MBT was detected in the Day 0 baseline samples. Caged reference mussels placed back in the Black Rock Channel Lock and retrieved on Days 19 and 34 had TBT, DBT, and MBT levels which did not differ significantly from the Day 0 baseline levels. Mussels placed at the Times Beach CPF had TBT concentrations that were significantly lower at both Days 19 (3.65 +/- 0.90 ng Sn/g) and 34 (3.50 +/- 1.03 ng Sn/g) than the Day 0 baseline analysis (5.86 +/- 0.43 ng Sn/g). The results of this study indicate that butyltins were detected at the CPF site in the sediment (7.33 +/- 5.70 ng Sn/g) but not the water column (not detected at 0.01 microgram/l). In this study the zebra mussel was able to depurate TBT even in the presence of contaminated sediment. TBT may be bioaccumulated from the sediments. However, the initial levels in the mussels were so high, levels actually dropped as sediment-tissue equilibria levels were reached by the mussels.

Discrimination of factors influencing biota of a stream receiving multiple-source perturbations.

Blaine Creek is a fifth-order stream located in eastern Kentucky that has been subject to contamination by oil brines, surface mining, and a coal fly ash settling pond discharge. Toxicity tests, effluent and receiving water chemical monitoring, and Blaine Creek benthic sampling were used to evaluate the effect of the ash pond effluent on the creek. Reproductive impairment of Ceriodaphnia was demonstrated at effluent concentrations ranging from 30 to 100%, but no instream impact on benthic invertebrates could be found at effluent flows that provided up to 65% of the creek's discharge. Correlation and regression analysis of physicochemical versus benthic monitoring data indicated that upstream oil brine contamination and scouring of the creek's predominately shifting sand substrate during rainfall events were the primary factors affecting the benthic fauna, and appeared to override potential effects from other sources. These results demonstrated the value of integrated field/laboratory investigations for effluent impact assessments.

Bioaccumulation of toxicants in the zebra mussel, Dreissena polymorpha, at the Times Beach Confined Disposal Facility, Buffalo, New York.

This study consisted of a site characterization followed by biomonitoring the zebra mussel, Dreissena polymorpha, at the Times Beach Confined Disposal Facility (CDF), located in Buffalo, New York. Concentrations of selected contaminants, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and metals -arsenic (As), chromium (Cr), barium (Ba), mercury (Hg), cadmium (Cd), lead (Pb), selenium (Se) and silver (Ag)-were at or below detection limits in the water column. Sediment contaminant concentrations, recorded as dry weight, were as high as 549 mg/kg for total PAHs, 9 mg/kg for PCB Aroclor 1248 and 54, 99, 6, 355, 637 and 16 mg/kg for the metals As, Ba, Cd, Cr, Pb and Hg, respectively. To predict contaminant bioavailability, elutriate and whole sediment toxicity tests were performed utilizing the cladoceran, Daphnia magna. Whole sediment tests indicated significant impact. Control survival was 84%, while sediment treatment had survival ranging from 1 to 7%. Mean control reproduction was 86.8 neonates, whereas treatment reproduction ranged from 1.4 to 9.0. Zebra mussels placed both in the water column (Upper) and at the sediment level (Lower) survived the 34-day exposure. Contaminants that significantly accumulated in zebra mussel tissue (wet wt mg/kg) were total PAHs (6.58), fluoranthene (1.23), pyrene (1.08), chrysene (0.98), benzo(a)anthracene (0.60), PCB Aroclor 1248 (1.64), As (0.97), Cr (2.87) and Ba (7.00). Accumulation of these contaminants in zebra mussel tissue represent a potentially realistic hazard to organisms (i.e. fish and birds) that feed on them.

An integrative assessment of a watershed impacted by abandoned mined land discharges.

The Ely Creek watershed in Lee County, VA, USA, contains an abundance of abandoned mined land areas with acid mine drainage (AMD) that contaminate the majority of the creek and its confluence into Stone Creek. Acidic pH measurements ranged from 2.73 to 5.2 at several stations throughout the watershed. Sediments had high concentrations of iron (approximately 10,000 mg kg-1), aluminum (approximately 1,500 mg kg-1), magnesium (approximately 400 mg kg-1) and manganese (approximately 150 mg kg-1), and habitat was partially to non-supporting at half of the stations due to sedimentation. Benthic macroinvertebrate surveys at six of 20 stations sampled in the watershed yielded no macroinvertebrates, while eight others had total abundances of only one to nine organisms. Four reference stations contained > or = 100 organisms and at least 13 different taxa. Asian clam in situ toxicity testing supported field survey results. Laboratory, 10-day survival/impairment sediments tests with Daphnia magna and Chironomus tentans and 48-h water column bioassays with Ceriodaphnia dubia indicated environmental stress to a lesser degree. Ten parameters that were directly influenced by AMD through physical, chemical, ecological and toxicological endpoints were assimilated into an ecotoxicological rating (ETR) to form a score of 0-100 points for the 20 sampling stations, and the lower the score the greater the AMD stress. Twelve of the 15 sampling stations influenced by AMD received an ETR score of 13.75-57.5, which were categorized as severely stressed (i.e. comprised the < 60 percentile category) and worthy of the highest priority for future ecological restoration activities in the watershed.

Calcified aldosterone-producing adrenocortical adenoma.

We report the first case of benign aldosteronoma of an ordinary size with calcifications. We review the clinical, clinical imaging, histopathological, and laboratory features of aldosterone-producing adrenal adenoma versus carcinoma. We conclude that no single feature is diagnostic, and the full range of data must be considered. Calcifications may not necessarily be a distinguishing point.