The re-eutrophication of Lake Erie: Harmful algal blooms and hypoxia.

Lake Erie supplies drinking water to more than 11 million consumers, processes millions of gallons of wastewater, provides important species habitat and supports a substantial industrial sector, with >$50 billion annual income to tourism, recreational boating, shipping, fisheries, and other industries. These and other key ecosystem services are currently threatened by an excess supply of nutrients, manifested in particular by increases in the magnitude and extent of harmful planktonic and benthic algal blooms (HABs) and hypoxia. Widespread concern for this important international waterbody has been manifested in a strong focus of scientific and public material on the subject, and commitments for Canada-US remedial actions in recent agreements among Federal, Provincial and State agencies. This review provides a retrospective synthesis of past and current nutrient inputs, impairments by planktonic and benthic HABs and hypoxia, modelling and Best Management Practices in the Lake Erie basin. The results demonstrate that phosphorus reduction is of primary importance, but the effects of climate, nitrogen and other factors should also be considered in the context of adaptive management. Actions to reduce nutrient levels by targeted Best Management Practices will likely need to be tailored for soil types, topography, and farming practices.

The use of local anaesthesia in haemorrhoidal banding: a randomized controlled trial.

AIM: Rubber band ligation is a common office procedure for the treatment of symptomatic haemorrhoids. It can be associated with pain and vasovagal symptoms. The effect of local anaesthetic use during banding was studied. METHOD: A single-blinded randomized controlled trial was carried out in the colorectal outpatient clinic. Patients presenting with symptomatic haemorrhoids suitable for banding were prospectively recruited and randomized to undergo the procedure with local anaesthetic or without (control). Submucosal bupivacaine was injected immediately after banding just proximal to the site. Vasovagal symptoms were assessed at the time of banding and pain scores (visual analogue scale) were recorded at the conclusion of the procedure, after 15 min, and on leaving the clinic. RESULTS: Seventy-two patients (40 local anaesthetic injection, group 1; 32 no injection, group 2) were recruited. The mean ages were 50 and 54 years respectively, the median duration of symptoms was 12 months in each group and the median number of haemorrhoids banded was three in each group. The mean pain score on leaving the clinic was 2.6 (95% CI 2.1, 3.1) in group 1 and 4.1 (95% CI 3.3, 5.0) (P = 0.04) in group 2. There were no complications related to local anaesthetic use. No significant difference in vasovagal symptoms was found (P = 0.832). CONCLUSION: Local anaesthetic injection at the time of banding is simple and safe. It may reduce patient discomfort following banding of haemorrhoids.

Something is amiss in Denmark: a comparison of preventable hospitalisations and readmissions for chronic medical conditions in the Danish Healthcare system and Kaiser Permanente.

BACKGROUND: As many other European healthcare systems the Danish healthcare system (DHS) has targeted chronic condition care in its reform efforts. Benchmarking is a valuable tool to identify areas for improvement. Prior work indicates that chronic care coordination is poor in the DHS, especially in comparison with care in Kaiser Permanente (KP), an integrated delivery system based in the United States. We investigated population rates of hospitalisation and readmission rates for ambulatory care sensitive, chronic medical conditions in the two systems. METHODS: Using a historical cohort study design, age and gender adjusted population rates of hospitalisations for angina, heart failure, chronic obstructive pulmonary disease, and hypertension, plus rates of 30-day readmission and mortality were investigated for all individuals aged 65+ in the DHS and KP. RESULTS: DHS had substantially higher rates of hospitalisations, readmissions, and mean lengths of stay per hospitalisation, than KP had. For example, the adjusted angina hospitalisation rates in 2007 for the DHS and KP respectively were 1.01/100 persons (95%CI: 0.98-1.03) vs. 0.11/100 persons (95%CI: 0.10-0.13/100 persons); 21.6% vs. 9.9% readmission within 30 days (OR = 2.53; 95% CI: 1.84-3.47); and mean length of stay was 2.52 vs. 1.80 hospital days. Mortality up through 30 days post-discharge was not consistently different in the two systems. CONCLUSIONS: There are substantial differences between the DHS and KP in the rates of preventable hospitalisations and subsequent readmissions associated with chronic conditions, which suggest much opportunity for improvement within the Danish healthcare system. Reductions in hospitalisations also could improve patient welfare and free considerable resources for use towards preventing disease exacerbations. These conclusions may also apply for similar public systems such as the US Medicare system, the NHS and other systems striving to improve the integration of care for persons with chronic conditions.

Mortality and cancer morbidity in a cohort of Canadian petroleum workers.

AIMS: To assess mortality and cancer morbidity in Canadian petroleum workers and explore exposure-response relations for specific petroleum agents. METHODS: A total of 25 292 employees hired between 1964 and 1994 were linked to the Canadian tumour registry and national mortality database. Exposure-response trends were assessed for hydrocarbon solvents/fuels, hydrocarbon lubricants, petroleum coke/spent catalyst, and hydrogen sulphide (H2S). RESULTS: External comparison analyses (mortality and incidence) showed deficits for all causes and all malignant neoplasms combined and were consistent with expectation for most malignant and non-malignant sites analysed. Gall bladder cancer mortality was increased among males based on four deaths, but cases had no common job assignments and the increase was focused in workers employed <10 years. Mesothelioma incidence was increased. Most exposure-specific analyses were compromised by small numbers. Statistically significant increases were observed for H2S exposure and a subgroup of accidental deaths as well as for petroleum coke/spent catalyst exposure and lung cancer. While both findings have a degree of biologic plausibility, the H2S association, which exhibited a clearer exposure-response pattern, could be subject to unmeasured confounders. Additionally, interpretation was complicated by the high correlation between hydrocarbon and H2S exposures. With regard to lung cancer, the analysis could not adequately control for smoking, was based on small numbers, and exhibited a tenuous exposure-response pattern. CONCLUSION: The findings for mesothelioma suggest the need for continued attention to asbestos in the petroleum industry. The relation between accidental deaths and H2S exposure deserves closer scrutiny in similarly exposed populations. Further analyses of lung cancer are underway and will be reported separately.

Limited stage small cell lung cancer.

The management of limited stage small cell lung cancer begins with a firm pathologic diagnosis and careful staging. Patients with adequate pulmonary function, ambulatory performance status, and no evidence of metastatic disease outside a "tolerable" local radiotherapy volume should have consultation from both medical and radiation oncology disciplines for planning of integrated therapy. The chemotherapy prescription recommended is cisplatin plus etoposide at standard doses for four chemotherapy cycles. Thoracic irradiation should be administered concurrently with the first or second cycle of cisplatin and etoposide. Patients with complete response and excellent partial response should receive prophylactic cranial irradiation after completion of all chemotherapy.

Updated mortality among diverse operating segments of a petroleum company.

OBJECTIVES: To update mortality for 34 560 employees from diverse operating segments of a Canadian petroleum company; and to investigate potential relations with occupational factors. METHODS: Employees from 1964-83 were linked to the Canadian mortality data base to provide 11 years additional follow up. There were 6760 deaths and 750 683 person-years of follow up compared with 3909 and 428 190, respectively, in the earlier study. Analyses used standardised mortality ratios (SMRs) to compare worker cause specific mortality with the Canadian general population. Duration of employment and latency analyses were performed for causes previously found to be increased in this and other petroleum cohorts, as well as any findings of interest. RESULTS: For the period 1964-94, employees experienced significantly low overall mortality (SMR=0.86 men, SMR=0.80 women). Kidney cancer, which has been increased in some studies of petroleum workers, was not increased. Acute non-lymphocytic leukaemia in exposed operating segments was consistent with the expected or only slightly, non-significantly increased. The most notable finding was increased deaths from mesothelioma among refinery and petrochemical workers (SMR 8.68; 95% confidence interval (95% CI) 5.51 to 13.03), most of whom were long term employees in jobs with presumed exposure to asbestos (mechanical and pipefitters). Deaths from multiple myeloma among marketing and distribution workers, which were previously increased, remained increased (SMR 2.08; 95% CI 0.95 to 3.95) in the update period 1984-94; however, there was no clear pattern by duration of employment or latency. Aortic aneurysms, which also were previously significantly increased among marketing and distribution workers approached the expected in the update period (SMR 1.18; 95% CI 0. 65-1.98). Analyses by duration of employment showed suggestive trends for aortic aneurysms, but earlier studies of this cohort have not found a relation between aortic aneurysms and exposure to hydrocarbons. CONCLUSION: The additional 2851 deaths and 322 493 person-years of follow up strengthened the assessment of mortality patterns relative to occupational factors. With the exception of mesothelioma, no clear work related increases in disease were identified.

Outcome evaluation of a multi-component violence-prevention program for middle schools: the Students for Peace project.

This study evaluated the effect of Students for Peace, a multi-component violence-prevention intervention, on reducing aggressive behaviors among students of eight middle schools randomly assigned into intervention or control conditions. The intervention, based on Social Cognitive Theory, included the formation of a School Health Promotion Council, training of peer mediators and peer helpers, training of teachers in conflict resolution, a violence-prevention curriculum, and newsletters for parents. All students were evaluated in the spring of 1994, 1995 and 1996 (approximately 9000 students per evaluation). Sixth graders in 1994 were followed through seventh grade in 1995 or eighth grade in 1996 or both (n = 2246). Cohort and cross-sectional evaluations indicated little to no intervention effect in reducing aggressive behaviors, fights at school, injuries due to fighting, missing classes because of feeling unsafe at school or being threatened to be hurt. For all variables, the strongest predictors of violence in eighth grade were violence in sixth grade and low academic performance. Although ideal and frequently recommended, the holistic approach to prevention in schools in which teachers, administrators and staff model peaceful conflict resolution is difficult to implement, and, in this case, proved ineffective. The Students for Peace experience suggests that interventions begin prior to middle school, explore social environmental intervention strategies, and involve parents and community members.

Maintenance intravenous iron therapy in hepmodialysis patients receiving recombinant human erythropoientin.

Iron Supplementation is crucial in raising hematocrit as well as dosage saving for recombinant human erythropoietin therapy (rHuEPO) in maintenance hemodialysis patients. Intravenous iron has proved to be both safe and efficacious in this patient's population. However, the exact iron requirement has not been worked our. In this study we found that 1000 mg of element iron (given as iron saccharate) per moth was effective in maintaining hematocrit and hemoglobin at 33% and 110 gm/L respectively, and reducing the erythropoietin (EPO) dosage by about 20% in maintenance hemodialysis patients who were iron-replete. The serum ferritin increased from 219+/-144 to 320+/-234 microg/L (P< 0.05). There were no major side effects and patients tolerated the monthly iron therapy well. Our study suggests that intravenous iron saccharate (100 mg/month) is effective and safe in patients on maintenance hemodialysis receiving RHUEPO.

Latent cochlear damage in personal stereo users: a study based on click-evoked otoacoustic emissions.

OBJECTIVE: To assess the effects of use of personal stereo systems (PS) on hearing by means of the objective measure of transient-evoked otoacoustic emissions. PARTICIPANTS AND SETTING: People aged between 10 and 59 years who had otoacoustic emissions recorded by the National Acoustic Laboratories between 1989 and 1997 were eligible for inclusion. Recordings from participants with hereditary disorders or any form of aural disease (e.g., otitis media, otosclerosis, fluctuant hearing loss, Meniere's syndrome, or exposure to ototoxic substances) were excluded. METHODS: Transient-evoked otoacoustic emission (TEOAE) records were obtained with a standard 260 repetitions of an 80 dB train of clicks used for recording outer hair cell activity. The measure of otoacoustic emission strength was the Otodynamics ILO88 variable Waverepro%. For each participant, all the key factors relating to their hearing history were assessed from patient referral information or from demographic information obtained in writing at the time of recording either in the form of a detailed questionnaire or verbal assessment. Otoacoustic emission data were analysed according to age, industrial noise exposure and personal stereo use. RESULTS: Usable otoacoustic emission records were obtained from 1724 people (1066 males and 658 females). Otoacoustic emission strength declined with age, and was significantly lower in males than females, lower in people exposed to industrial noise than those not exposed, and significantly lower in users of personal stereo systems than non-users. People with both kinds of noise exposure had values which were significantly lower again, indicating an additive effect. CONCLUSIONS: As only 39 people with PS exposure admitted any hearing problems, decline in otoacoustic emission strength forewarns premature hearing loss in personal stereo users.

Retrospective benzene and total hydrocarbon exposure assessment for a petroleum marketing and distribution worker epidemiology study.

A quantitative exposure-estimating algorithm for benzene and total hydrocarbons was developed for a case control study of petroleum marketing and distribution workers. The algorithm used a multiplicative model to adjust recently measured quantitative exposure data to past scenarios for which representative exposure measurement data did not exist. This was accomplished through the development of exposure modifiers to account for differences in the workplace, the materials handled, the environmental conditions, and the tasks performed. Values for exposure modifiers were obtained empirically and through physical/chemical relationships. Dates for changes that altered exposure potential were obtained from archive records, retired employee interviews, and from current operations personnel. Exposure modifiers were used multiplicatively, adjusting available measured data to represent the relevant exposure scenario and time period. Changes in exposure modifiers translated to step changes in exposure estimates. Though limited by availability of data, a validation exercise suggested that the algorithm provided accurate exposure estimates for benzene (compared with measured data in industrial hygiene survey reports); the estimates generally differed by an average of less than 20% from the measured values. This approach is proposed to quantify exposures retrospectively where there are sufficient data to develop reliable current era estimates and where a historical accounting of key exposure modifiers can be developed, but where there are insufficient historic exposure measurements to directly assess historic exposures.

Tyrosine 27 of the specificity polypeptide of EcoKI can be UV crosslinked to a bromodeoxyuridine-substituted DNA target sequence.

The specificity (S) subunit of the restriction enzyme EcoKI imparts specificity for the sequence AAC(N6)GTGC. Substitution of thymine with bromodeoxyuridine in a 25 bp DNA duplex containing this sequence stimulated UV light-induced covalent crosslinking to the S subunit. Crosslinking occurred only at the residue complementary to the first adenine in the AAC sequence, demonstrating a close contact between the major groove at this sequence and the S subunit. Peptide sequencing of a proteolytically-digested, crosslinked complex identified tyrosine 27 in the S subunit as the site of crosslinking. This is consistent with the role of the N-terminal domain of the S subunit in recognizing the AAC sequence. Tyrosine 27 is conserved in the S subunits of the three type I enzymes that share the sequence AA in the trinucleotide component of their target sequence. This suggests that tyrosine 27 may make a similar DNA contact in these other enzymes.

Polyphenols, astringency and proline-rich proteins.

Recent, NMR and precipitation, studies of molecular recognition of proline-rich proteins and peptides by plant polyphenols are described and rationalized. The action of polysaccharides and caseins in the moderation of the astringent response, which is engendered by polyphenols present in foodstuffs and beverages, is described. The possible influence of plant cell wall glycoproteins on the process of lignification is discussed in the light of the observed affinity of phenolic substrates for prolyl residues in protein structures.

LCB 2183 inhibits the inflammation associated with oxazolone-induced contact sensitivity.

LCB 2183, an anti-allergic and potential anti-asthma compound, has been investigated for its ability to inhibit contact sensitivity in the mouse. The delayed response to epicutaneous hapten challenge in this model is a classical T-cell-mediated inflammatory reaction which is dependent on an early initiation phase. Both the early and late components of oxazolone-induced contact sensitivity were inhibited by oral administration of LCB 2183 in a dose-dependent manner. The drug appears to act on the efferent limb of the response since administration before hapten challenge was effective, while administration before the initial sensitization was not. LCB 2183 acts early in the cascade of events leading to inflammation, since the initiation phase of the response was inhibited; nonetheless, an effect of the drug on the late acting inflammatory cells cannot be ruled out. In comparison with oral prednisolone, which was also able to inhibit both the early and late components of the response, LCB 2183 was less active. Sodium cromoglycate and nedocromil sodium, which are poorly absorbed from the gastrointestinal tract, were tested by intraperitoneal administration. Neither of these agents significantly altered the delayed response and only nedocromil sodium had a limited inhibitory effect on the early initiation phase. Thus, in this model, LCB 2183 demonstrated more anti-inflammatory potential and resembled prednisolone more closely than either nedocromil sodium or sodium cromoglycate. The possible relevance of these effects in relation to the inflammation which characterizes human asthma is considered.

A retrospective mortality study within operating segments of a petroleum company.

This retrospective mortality study was conducted among 34,597 oil industry workers in diverse operating segments. Employees were traced through Statistics Canada, and overall mortality (SMR = 0.85) was lower than general population rates and similar to other petrochemical cohorts. The most notable finding was a significant excess of malignant melanoma [observed deaths (N) = 16, SMR = 1.87, 95% CI = 1.07, 3.04], which concentrated among upstream workers (N = 6, SMR = 6.00, 95% CI = 2.19, 13.06), and was directly related to employment duration and latency. Specific substances or hydrocarbon (HC) streams could not be implicated, although possible explanations include dermal HC exposure, ultraviolet light exposure, or a synergistic effect between these two factors. Marketing/transportation workers showed a non-significant excess of multiple myeloma (SMR = 1.81), which was also related to employment duration, latency, and commencement of employment before 1950. Lymphatic cancer, skin cancer, and kidney cancer mortality was not elevated in refinery workers, a finding at odds with some previous refinery worker studies. Although the malignant melanoma and possibly the multiple myeloma mortality patterns are consistent with an occupational link, further studies are needed to investigate the relationship of these diseases with particular exposures.

Alternating current at the eardrum for tinnitus reduction.

The effectiveness of alternating current (AC) stimulus on tinnitus was investigated in 10 patients who reported constant tinnitus in at least one ear. Patients were first screened to determine their responsiveness to electrical stimulation in relation to tinnitus reduction. The responsive patients were then stimulated for a treatment period of at least 10 min, during which time the tinnitus was measured. The AC stimuli (62 Hz to 8000 Hz) were applied to the eardrum of the patients via a specially constructed electrode. Psychophysical measurements (pitch matching, loudness matching, minimum masking level, and loudness and annoyance scaling) of the patient's tinnitus were made before and after electrical stimulation. Minimal masking level was determined and tinnitus scaling was performed during the treatment period. Electrical stimulation was effective in tinnitus reduction in 5 of the 10 patients. These 5 patients reported that the loudness and the annoyance of their tinnitus decreased during the treatment period. These observations were consistent with psychophysical measures of contralateral broadband noise masking. Poststimulation reduction in tinnitus varied in duration among individuals from 40 s to about 4 hr.

Reference values of blood parameters in beef cattle of different ages and stages of lactation.

Reference (normal) values for 12 blood serum components were determined for 48 Shorthorn cows (2-10 years old) and their 48 calves, 357 crossbred cows (12-14 years old), 36 feedlot bulls and 36 feedlot steers. In addition, hemoglobin, hematocrit, triiodothyronine, thyroxine and cortisol levels were determined for the crossbred cows, and feedlot bulls and steers. Reference values were tabulated according to sex, age and stage of lactation. Serum concentrations of urea, total protein and bilirubin, and serum activity of aspartate aminotransferase and lactate dehydrogenase increased with age (P less than 0.05), while calcium, phosphorus and alkaline phosphatase decreased with age (P less than 0.05) from birth to the age of ten years. The Shorthorn cows had the highest levels of glucose at parturition (P less than 0.05) with decreasing levels during lactation. Creatinine concentration decreased during lactation and increased during postweaning. Both lactate dehydrogenase and aspartate aminotransferase levels increased (P less than 0.05) during lactation. Urea and uric acid were present at higher concentrations in lactating than nonlactating cows (P less than 0.05). The values reported, based on a wide age range and large number of cattle, could serve as clinical guides and a basis for further research.

Nutritional support for the infant with extrahepatic biliary atresia.

Some infants with biliary atresia obtain dramatic improvement for prolonged periods after the performance of hepatic portoenterostomy. Such infants may have life styles not substantially different from those of normal children. In others, the benefit from this operation, if any, is short lived. These infants are very vulnerable to the debilitating effects of severe, prolonged malabsorption and ultimately require orthotopic liver transplantation to sustain life. The physician caring for infants awaiting liver transplantation can do much, not only to prolong survival but to maintain satisfactory growth and development. The key consideration is to provide adequate nitrogen and nonnitrogen calories, liberally utilizing modern methods of enteral alimentation when necessary. In addition, attention must be directed toward several vitamin and mineral deficiencies, particularly those of the fat-soluble vitamins, that inevitably accompany severe malabsorption in children. Management of extrahepatic biliary atresia in infants is difficult and requires meticulous attention to details. Nevertheless, the long-term cure of this disorder provided by liver transplantation makes their care a rewarding experience.