Multimodality treatment of intracranial arteriovenous malformations in South Island, New Zealand.

Treatment of intracranial arteriovenous malformations is complex and multidisciplinary. This article presents the treatment model utilized in Christchurch, New Zealand which provides cerebrovascular surgery and interventional neuroradiology to the entire south island (approximate population of 1.1 million). A total of 40 patients treated over a 10 year period (2004-2014) are analysed here. Nine patients were managed surgically and complete resection was achieved in 100% of cases. Permanent mortality was 0% and permanent morbidity was 22% however median mRS improved from 3.0 preoperatively to 1.0 at follow up. Embolisation was utilized in 31 patients (mean age 40), of which 45% presented with haemorrhage, 39% with seizures, 10% with a headache only, and 6% with a deficit. None were found incidentally. The Spetzler-Martin grade 1 cases accounted for 10% of the cohort, 23% were grade II, 42% grade III, 23% grade IV and 3% grade V. A single aneurysm was present in 42% of cases, and multiple in 13%. The nidus was obliterated in 9.6% of cases with a morbidity rate of 6.5% and mortality rate of 3%. Modified Rankin scale improved marginally from 0.9 at diagnosis to 0.88 at final follow up (mean 22 months). There were no cases of recanalization. The total nidus obliteration rate using our algorithm of surgery alone for small accessible lesions, then staged embolization for larger lesions with adjuvant radiosurgery reserved for cases with residual nidus, was 50%.

Microbial water pollution: a screening tool for initial catchment-scale assessment and source apportionment.

The European Union Water Framework Directive requires that Management Plans are developed for individual River Basin Districts. From the point of view of faecal indicator organisms (FIOs), there is a critical need for screening tools that can provide a rapid assessment of the likely FIO concentrations and fluxes within catchments under base- and high-flow conditions, and of the balance ('source apportionment') between agriculture- and sewage-derived sources. Accordingly, the present paper reports on: (1) the development of preliminary generic models, using water quality and land cover data from previous UK catchment studies for assessing FIO concentrations, fluxes and source apportionment within catchments during the summer bathing season; (2) the calibration of national land use data, against data previously used in the models; and (3) provisional FIO concentration and source-apportionment assessments for England and Wales. The models clearly highlighted the crucial importance of high-flow conditions for the flux of FIOs within catchments. At high flow, improved grassland (and associated livestock) was the key FIO source; FIO loadings derived from catchments with high proportions of improved grassland were shown to be as high as from urbanized catchments; and in many rural catchments, especially in NW and SW England and Wales, which are important areas of lowland livestock (especially dairy) farming, ≥ 40% of FIOs was assessed to be derived from agricultural sources. In contrast, under base-flow conditions, when there was little or no runoff from agricultural land, urban (i.e. sewerage-related) sources were assessed to dominate, and even in rural areas the majority of FIOs were attributed to urban sources. The results of the study demonstrate the potential of this type of approach, particularly in light of climate change and the likelihood of more high-flow events, in underpinning informed policy development and prioritization of investment.

Pharmacological modulation of gut mucosal and large vessel blood flow.

BACKGROUND: Constipation, diminished gut blood flow, ischaemic colitis and drug therapy may be associated. AIM: To study the effect of constipating medication on, and the regulation of, gut blood flow. METHODS: 24 healthy females (mean age 30) received, in a double-blind, three-way crossover study: (i) placebo, (ii) ipratropium 40 microg by inhalation (positive control known to reduce rectal mucosal blood flow) and (iii) oral loperamide 4 mg. Mucosal blood flow was measured at the splenic flexure and rectum using laser Doppler flowmetry. Blood flow in the superior and inferior mesenteric arteries was measured by trans-abdominal Doppler ultrasound. RESULTS: Ipratropium decreased rectal mucosal blood flow by 16% (P=0.009) and splenic flexure mucosal blood flow by 8% (P=0.075). Loperamide caused no change in rectal (P=0.40) or splenic flexure mucosal blood flow (P=0.73). Neither treatment changed superior or inferior mesenteric artery blood flow. Splenic flexure mucosal blood flow showed a positive correlation with rectal mucosal blood flow (r=0.69; P<0.0001). CONCLUSIONS: Vasoactive agents may reduce gut mucosal blood flow in the absence of reduced large vessel flow. Constipating drugs do not necessarily reduce gut blood flow. Rectal mucosal blood flow correlates with splenic flexure mucosal flow, and potentially may be used as a more convenient surrogate for studying splenic flexure blood flow.

Review article: Population screening for colorectal cancer.

Colorectal cancer is a common cancer and common cause of death. The mortality rate from colorectal cancer can be reduced by identification and removal of cancer precursors, adenomas, or by detection of cancer at an earlier stage. Pilot screening programmes have demonstrated decreased colorectal cancer mortality; as a result many countries are developing colorectal cancer screening programmes. The most common modalities being evaluated are faecal occult blood testing, flexible sigmoidoscopy and colonoscopy. Implementation of screening tests has been hampered by cost, invasiveness, availability of resources and patient acceptance. New technologies such at computed tomographic colonography and stool screening for molecular markers of neoplasia are in development as potential minimally invasive tools. This review considers who should be screened, which test to use and how often to screen.

Measuring ammonia emissions from land applied manure: an intercomparison of commonly used samplers and techniques.

A number of techniques have been developed to quantify ammonia (NH(3)) emissions following land application of manure or fertiliser. In this study, coefficients of variation were determined for three commonly used field techniques (mass balance integrated horizontal flux, wind tunnels and the equilibrium concentration technique) for measuring emissions from a range of manure types. Coefficients of variation (CV) for absorption flasks, passive flux samplers and passive diffusion samplers were 21, 10 and 14%, respectively. In comparative measurements, concentrations measured using passive flux samplers and absorption flasks did not differ significantly, but those measured using passive diffusion samplers were on average 1.8 times greater. The mass balance technique and wind tunnels gave broadly similar results in two out of four field tests. Overexposure of passive diffusion samplers for some sampling periods meant that estimation of cumulative NH(3) emission using the equilibrium concentration technique in the field tests could not be made. For cumulative NH(3) emissions, CVs were in the range of 23-52, 46-74 and 21-39% for the mass balance, wind tunnel and equilibrium concentration techniques, respectively. Lower CVs were associated with measurements following slurry compared with solid manure applications. Our conclusions from this study are that for the measurement of absolute emissions the mass balance technique is to be preferred, and for small-plot comparative measurements the wind tunnel system is preferred to the equilibrium concentration technique.

Recent developments in CT colonography.

CT colonography allows reliable, non-invasive, rapid, high resolution imaging of the whole large bowel. Recent advances in technology such as computer-aided detection (CAD), scanning with or without bowel preparation, and low radiation are continually developing to improve the efficacy of this technique. This review will update the reader as to ongoing developments while presenting current thinking from the gastroenterological perspective.

Experimental pain thresholds influenced by sex of experimenter.

Thresholds for pressure pain were tested in 64 adult human subjects (age: M=22.0 yr., SD=7.5). The subjects were young adults drawn from a student population. They were divided into two groups of men and two groups of women, with 16 participants in each group. A female experimenter tested one group of men and a male experimenter tested the other group. The women were tested in a similar way by an experimenter of the same sex for one group and the opposite sex for the other group. The two experimenters were dressed in a manner that emphasised their gender roles. The men tested by a female experimenter showed a higher average pain threshold than the men tested by a male experimenter, but there was no difference in the average pain thresholds of the two groups of women.

Predicting ammonia losses following the application of livestock manure to land.

A series of experiments was conducted using small wind tunnels to assess the influence of a range of environmental, manure and management variables on ammonia emissions following application of different manure types to grassland and arable land. Wind speed and dry matter content (for cattle slurry in particular) were identified as the parameters with greatest influence on ammonia emissions from slurries. For solid manures, rainfall was identified as the parameter with most influence on ammonia emissions. A Michaelis-Menten function was used to describe emission rates following manure application. Linear regression was then used to develop statistical models relating the Michaelis-Menten function parameters to the experimental variables for each manure type/land use combination. The fitted models accounted for between 62% and 94% of the variation in the data. Validation of the models for cattle slurry to grassland and pig slurry to arable land against independent data sets obtained from experiments using the micrometeorological mass balance measurement technique showed that the models overestimated losses, which was most probably due to inherent differences between the wind tunnel and the micrometerological mass balance measurement techniques.

Factors affecting the concentrations of lead in British wheat and barley grain.

The entry of Pb into the food chain is of concern as it can cause chronic health problems. The concentration of Pb was determined in cereal grain samples collected representatively from British Cereal Quality Surveys in 1982 and 1998 (n = 176, 250 and 233 for wheat collected in 1982 and 1998, and barley in 1998, respectively). In addition, paired soil and grain samples were collected from 377 sites harvested across Britain in 1998-2000. Wheat grain Pb ranged from below the analytical detection limit (0.02 mg kg(-1) dry weight, DW) to 1.63 mg kg(-1) DW, and barley grain Pb from <0.02 to 0.48 mg kg(-1) DW. The vast majority of samples (>99% for both wheat and barley, excluding Scottish barley samples collected in 2000) were well below the newly introduced EU limit for the maximum permissible concentration of Pb in cereals (0.2 mg kg(-1) fresh weight, equivalent to 0.235 mg kg(-1) DW). There was a significant reduction in wheat grain Pb in the 1998 survey compared with the 1982 survey. However, 40 barley samples collected from Scotland in 2000 in the paired soil and crop survey showed anomalously high concentrations of Pb, with 10 samples exceeding the EU limit. Washing experiments demonstrated that surface contamination, introduced during grain harvest and/or storage, was the main reason for the high concentrations in these samples. In the paired soil and crop surveys, there were no significant correlations between grain Pb concentrations with total soil Pb and other soil properties, indicating low bioavailability of Pb in the soils and limited uptake and transport of Pb to grain. The Pb in cereal grain is likely to originate mainly from atmospheric deposition and other routes of surface contamination during harvest and storage.

Predicting cadmium concentrations in wheat and barley grain using soil properties.

The entry of Cd into the food chain is of concern as it can cause chronic health problems. To investigate the relationship between soil properties and the concentration of Cd in wheat (Triticum aestivum L.) and harley (Hordeum vulgare L.) grain, we analyzed 162 wheat and 215 barley grain samples collected from paired soil and crop surveys in Britain, and wheat and barley samples from two long-term sewage sludge experiments. Cadmium concentrations were much lower in barley grain than in wheat grain under comparable soil conditions. Multiple regression analysis showed that soil total Cd and pH were the significant factors influencing grain Cd concentrations. Significant cultivar differences in Cd uptake were observed for both wheat and barley. Wheat grain Cd concentrations could be predicted reasonably well from soil total Cd and pH using the following model: log(grain Cd) = a + b log(soil Cd) - c(soil pH), with 53% of the variance being accounted for. The coefficients obtained from the data sets of the paired soil and crop surveys and from long-term sewage sludge experiments were similar, suggesting similar controlling factors of Cd bioavailability in sludge-amended or unamended soils. For barley, the model was less satisfactory for predicting grain Cd concentration (22% of variance accounted for). The model can be used to predict the likelihood of wheat grain Cd exceeding the new European Union (EU) foodstuff regulations on the maximum permissible concentration of Cd under different soil conditions, particularly in relation to the existing Directive and the proposed new Directive on land applications of sewage sludge.

An inventory of heavy metals inputs to agricultural soils in England and Wales.

An inventory of heavy metal inputs (Zn, Cu, Ni, Pb, Cd, Cr, As and Hg) to agricultural soils in England and Wales in 2000 is presented, accounting for major sources including atmospheric deposition, sewage sludge, livestock manures, inorganic fertilisers and lime, agrochemicals, irrigation water, industrial by-product 'wastes' and composts. Across the whole agricultural land area, atmospheric deposition was the main source of most metals, ranging from 25 to 85% of total inputs. Livestock manures and sewage sludge were also important sources, responsible for an estimated 37-40 and 8-17% of total Zn and Cu inputs, respectively. However, at the individual field scale sewage sludge, livestock manures and industrial wastes could be the major source of many metals where these materials are applied. This work will assist in developing strategies for reducing heavy metal inputs to agricultural land and effectively targeting policies to protect soils from long-term heavy metal accumulation.

Effects of past sewage sludge additions on heavy metal availability in light textured soils: implications for crop yields and metal uptakes.

The effect of heavy metal additions in past sewage sludge applications on soil metal availability and the growth and yield of crops was evaluated at two sites in the UK. At Gleadthorpe, sewage sludges enriched with salts of zinc (Zn), copper (Cu) and nickel (Ni) had been applied to a loamy sand in 1982 and additionally naturally contaminated Zn and Cu sludge cakes in 1986. At Rosemaund, sewage sludges naturally contaminated with Zn, Cu, Ni and chromium (Cr) had been applied in 1968-1971 to a sandy loam. From 1994 to 1997, the yields of both cereals and legumes at Gleadthorpe were up to 3 t/ha lower than the no-sludge control where total topsoil Zn and Cu concentrations exceeded 200 and 120 mg/kg, respectively, but only when topsoil ammonium nitrate extractable metal levels also exceeded 40 mg/kg Zn and 0.9 mg/kg Cu. At Rosemaund, yields were only decreased where total topsoil Cu concentrations exceeded 220 mg/kg or 0.7 mg/kg ammonium nitrate extractable Cu. These results demonstrate the importance of measuring extractable as well as total heavy metal concentrations in topsoils when assessing likely effects on plant yields and metal uptakes, and setting soil quality criteria.

Comparison of the effect of surface application and subsurface incorporation of enhanced treated biosolids on the leaching of heavy metals and nutrients through sand and sandy loam soils.

Use of enhanced treated biosolids such as composted and dried, mesophilic anaerobically digested, dewatered (MADD) biosolids is becoming more popular. This is mainly in response to concerns over the potential for pathogens to enter the food chain. There is, therefore, a need to investigate how enhanced treatment, and methods by which these biosolids are applied, affects the leaching potential of metal and nutrients to ensure that water quality is not compromised. MADD cake (fresh, dried and composted) and MAD liquid sludge were applied by surface application and subsurface incorporation to sand (typic quartzipsamments, %OM = 3.0, pH = 6.5), sandy loam (typic hapludalf, %OM = 4.8, pH = 7.6) and silversand 'repacked semi-structured cores' (0.2 m by 0.1 m diameter) at rates equivalent to 250 kg N ha(-1) yr(-1). Leaching of Zn, Cu, Pb, Ni, N and P was investigated following application of five 8 h simulated rainfall events (4.9 mm h(-1)) in the laboratory. Little difference was observed between leaching of metals and nutrients from soils amended with enhanced treated biosolids (dried and composted MADD cakes) compared with conventional biosolids (fresh MADD cake and MAD liquid). Subsurface incorporation increased the risk of P and metal leaching compared with surface application. Nitrate losses were independent of application method. Similar nutrient losses from control and amended cores indicated that the leaching was derived predominantly from the soil clay and organic matter complexes. Evidence for attenuation of biosolids-derived metals and P by soil-derived clay and/or organic matter was found. Water balance data showed that hydrological regimes of each core were comparable and unlikely to account for observed differences in leaching losses.

Delayed referral reduces the success of video-assisted thoracoscopic debridement for post-pneumonic empyema.

The aim of this study was to evaluate the effect of preoperative delay on the efficacy of video-assisted thoracoscopic surgery (VATS) for post-pneumonic pleural empyema (PPE). This was a prospective study of 39 consecutive patients with PPE who were treated by VATS with curative intent over a 4-year period. Failure to obtain full lung re-expansion resulted in conversion to thoracotomy. Pre- and post-operative variables were correlated with surgical outcome. VATS debridement was successful in 16 (41%) patients while conversion to open decortication was needed in 23 patients (21 immediate, two delayed), There was no difference in the age/sex distribution of the two groups. In the failed VATS group the delay from hospital admission to operation was longer: 24 (2.1) vs. 16.6 (2.7) days (P = 0.03, 95% CI 0.53-14.3 days); operating time was longer: 128.2 (7.9) vs. 86.2 (10.4) min (P = 0.003, 95% CI 15.2-68.5 min) and post-operative stay was longer: 8.4 (0.8) vs. 5.2 (0.6) days (P = 0.03, 95% CI 1.1-5.3 days). VATS can be used successfully to treat PPE with a faster post-operative recovery when successful than open surgery. Delayed surgical intervention decreases the success of VATS thus earlier referral for surgical intervention in PPE (ideally within 21 days) is advocated to gain its full benefits.

Effect of drying and composting biosolids on the movement of nitrate and phosphate through repacked soil columns under steady-state hydrological conditions.

Effects of two "enhanced" treatments (drying and composting mesophilic anaerobically digested (MAD) biosolid) on nutrient leaching were investigated. Repacked sandy or sandy loam textured soil cores amended with fresh, dried and composted MAD biosolid (250 kg N ha(-1)), were investigated under steady-state hydrological conditions. Two 24 h, 4.5 mm h(-1) rainfall events, with a 14-day interval, were simulated using water-tracers. Losses of nitrate from the sandy loam soil during rainfall event 1 (43.9-68.0 mg kg(-1)) were significantly greater (P < or = 0.05) than during event 2 (6.4-11.9 mg kg(-1)). Phosphate losses were significantly greater (P < or = 0.05) during event 2 (up to 0.30 mg kg(-1)) compared to the first (< 0.05 mg kg(-1)). The sand soil showed similar effects. Losses of nitrate-N (percentage of total N applied) from the sand soil were small (around 0.06% for fresh/dried and 0.63% for composted MAD biosolids). Losses of nitrate-N from the sandy loam soil were greater; 4% for fresh and dried and 3% for composted MAD biosolids. This research showed that drying MAD biosolid had little impact on nitrate and phosphate losses from soil compared to fresh MAD biosolid. The effect of composting MAD biosolid on nutrient losses was more variable.

Movement of water and heavy metals (Zn, Cu, Pb and Ni) through sand and sandy loam amended with biosolids under steady-state hydrological conditions.

New guidelines for using biosolids in UK agriculture favour the use of enhanced treated biosolids, such as dried and composted cakes, due to concerns about the potential for transfer of pathogens into the food chain. However, there is a need to ensure that their use is environmentally acceptable and does not increase the risk to potable water supplies or the food chain from other contaminants such as heavy metals and xenobiotic organic chemicals. The objective of this study was to determine whether the use of composted and dried mesophilic anaerobically digested dewatered (MADD) biosolids would increase the risk of heavy metal leaching from cultivated horizons when compared to more conventionally used MADD cake. Three biosolids (MADD sewage sludge cake - fresh, dried and composted) were mixed with a sand (typic quartzipsamments, %OM = 3.0, pH = 6.5) or a sandy loam (typic hapludalf, %OM = 4.8, pH = 7.6) at an application rate equivalent to 250 kg N/ha/y resulting in loadings of approximately Zn: 6 microg, Cu: 2 microg, Pb: 5 microg and Ni: 0.2 microg/g of soil dry weight basis. These amended soils were repacked into columns (0.4 m by 0.1 m internal diameter) and leaching of Zn, Cu, Pb and Ni was investigated following application of two 24 h simulated rainfall events of 4.5 mm/h. Water balance data and the use of conservative tracers (Cl- and Br ) showed that the hydrological regimes of each core were comparable and, thus, unlikely to account for differences in metal leaching observed. Although no significant difference (P = 0.05) was observed between biosolid amended and control soils, those amended with composted sludge consistently gave higher loss of all metals than did the control soils. Total losses of metals from compost amended soil over the two rainfall events were in the ranges, Zn:20.5-58.2, Cu:9.0-30.5, Pb:24.2-51.2 and Ni:16.0-39.8 microg metal/kg amended soil, compared with Zn:16.4-41.1, Cu:6.2-25.3, Pb:16.9-41.7, and Ni:3.7-25.4 microg metal/kg soil from the control soils. Losses of Zn, Cu, Pb and Ni from fresh MADD cake amended soils (19.8-41.3, 3.2-25.8, 21.6-51.6 and 7.6-36.5 microg metal/kg amended soil, respectively) and from dry MADD cake amended soils (10.7-36.7, 1.8-23.8, 21.2-51.2 and 6.8-39.2 microg metal/kg amended soil, respectively) were similar to the controls. Generally, quantities of metals leached followed the order Zn = Pb > Cu > Ni, which was consistent with the levels of metals in the original sludge/soil mixtures. These results suggest that composting or drying MADD biosolids is unlikely to increase the risk of groundwater contamination when compared to the use of MADD cake; therefore, the changes in UK sludge use in agriculture guidelines are satisfactory in this respect.

Distribution of colorectal adenomas: implications for bowel cancer screening.

OBJECTIVE: To determine the distribution of colorectal adenomas relative to the splenic flexure in an asymptomatic population undergoing colonoscopy, as an indicator of the number of patients with adenomas who would be missed by screening with flexible sigmoidoscopy. DESIGN: Retrospective survey of medical records. SETTING: Private endoscopy centres in Melbourne, Victoria. SUBJECTS: All 1131 asymptomatic individuals who underwent full colonoscopy between 1 January 1995 and 31 December 1997 after referral from a bowel cancer prevention program organised by the endoscopy centres. People referred were aged either 40 years or over with a first-degree relative with bowel cancer, or 50 years or over with marked anxiety about bowel cancer. MAIN OUTCOME MEASURES: Presence and distribution of colorectal adenomas. RESULTS: Polyps were found in 270 individuals (24%) and were confirmed to be adenomas in 138 (12%). These 138 comprised 106 men and 32 women, with mean age 54 years (range, 40-78 years). Most (86%) had a single adenoma. Position of adenomas in relation to the splenic flexure was: distal only in 85 of the 138 people (62%), proximal only in 34 (25%), and both distal and proximal in 19 (14%). CONCLUSIONS: In 25% of asymptomatic people found to have adenomas by this bowel cancer prevention program, the adenomas were found only in the proximal colon, well beyond the reach of the flexible sigmoidoscope. This distribution of adenomas suggests that screening programs cannot rely solely on flexible sigmoidoscopy.

Percutaneous endoscopic gastrostomy: a review of indications, complications and outcome.

Percutaneous endoscopic gastrostomy (PEG) was first described in 1980 as an effective method of feeding via the stomach in situations where oral intake is not possible. Its simplicity has led to its potential use in areas of dubious clinical benefit. Our unit has faced a major increase in referrals for PEG insertion over the last 2 years. For this reason we decided to audit our PEG insertion procedures with regard to indications, complications, outcome and follow up. We studied 168 patients who had an initial PEG insertion during the period 1 February 1996-31 January 1998. The medical records of these patients were reviewed with regard to the procedure, antibiotic use and complications. All patients (or carers or next of kin) were contacted by telephone to provide details regarding late complications and follow up. There were 87 females and 81 males (aged 16-98 years, median age 70 years). At 2 years, 67% were alive. The most frequent indication for PEG insertion was a neurological condition, the commonest being stroke. Most patients received either ticarcillin/clavulanic acid or cephazolin antibiotic prophylaxis before and after the procedure. In six patients (3.6%) infection at the PEG site required intravenous antibiotics. Four of these six patients did not have antibiotic prophylaxis. Only two deaths could be directly related to the procedure. Three died within 7 days of the procedure due to unrelated medical complications. Sixteen patients died within 1 month, the majority of these patients did not leave hospital. One-fifth of the patients (35/168) had their PEG removed due to the re-establishment of oral feeding, with median time of use, 4.3 months. It is a safe, effective feeding method in the elderly, but experience with case selection, the procedure and careful follow up remain essential. The use of prophylactic antibiotics resulted in few significant infections of the PEG site. Up to one-fifth of patients will require their PEG only for a short term.

Lansoprazole quadruple therapy is effective in curing Helicobacter pylori infection.

BACKGROUND: Quadruple therapy using omeprazole combined with classic bismuth triple therapy has been advocated as optimal therapy for the cure of Helicobacter pylori (H. pylori) infection. We investigated the efficacy of substituting lansoprazole for omeprazole in proton pump quadruple therapy. MATERIALS AND METHODS: In a prospective open study, 219 consecutive patients, with either peptic ulcer disease or biopsy-proven H. pylori-associated gastritis, received seven days of lansoprazole, bismuth, tetracycline and metronidazole after three days of lansoprazole pretreatment. Cure of infection was judged by 14C urea breath test at six weeks after completion of therapy. RESULTS: On an intention to treat basis, 198 of the 219 patients (90%) were confirmed to be cured of H. pylori infection. Compliance was excellent and minimal side effects reported. CONCLUSION: Lansoprazole-based quadruple therapy achieves a very high cure rate in an unselected population of either peptic ulcer patients or those with H. pylori-associated gastritis. Recommended regimens should achieve at least 90% cure of infection. Lansoprazole quadruple therapy is effective and compares favorably with other H. pylori treatment regimens.