Robust reservoir identification by multi-well cluster analysis of wireline logging data.

A novel clustering method is applied to well logs for improved rock type identification in hydrocarbon formations. For grouping the objects in the multi-dimensional data space, we propose a Most Frequent Value (MFV) based clustering technique applied to natural gamma ray, bulk density, sonic, photoelectric index, and resistivity logs. The MFV method is a robust estimator, which assists in finding the cluster centers more reliably than a more noise sensitive K-means clustering approach. The result of K-means cluster analysis highly depends on the choose of the initial centroids. To reduce the risk of inappropriately chosen starting values, we apply a histogram-based selection method to give the best position of the initial cluster centers. We assure the robustness of the solution by calculating the centroid as the MFV of the cluster elements and defining the overall deviation of cluster elements from the center by a weighted Euclidean (Steiner-) distance. The proposed workflow relies on a fully automated weighting of the cluster elements, which does not require a constraint on the statistical distribution of the observed variables. The processing of synthetic data shows high noise rejection capability and efficient cluster recognition even beside considerable amount of outlying and missing data; the accuracy is measured by the difference between the estimated and the exactly known distribution of cluster numbers. The clustering tool is first applied to single borehole data, then the procedure is extended to multi-well logging datasets to reconstruct the multi-dimensional spatial distributions of clusters revealing the lithological and petrophysical characteristics of the studied formations. A large in situ dataset acquired from several boreholes traversing Hungarian gas-bearing clastic reservoirs of Miocene age is analyzed. The accuracy of the field results is confirmed by core permeability measurements, independent well log analysis and a gradient metrics characterizing the noise rejection capability of the clustering method.

Connection between microstructural alterations detected by diffusion MRI and cognitive dysfunction in MS: A model-free analysis approach.

BACKGROUND: Cognitive decline is a prominent symptom of MS. Clear connection between cognitive status and white matter microstructural changes has not been unequivocally observed to date. OBJECTIVE: To characterise the relationship between white matter microstructure and cognitive performance a partial least squares (PLS) approach was used. METHODS: 53 RR MS patients' T1 and DTI images and BICAMS subtests were used in our analysis. Standard FSL pipeline was used to obtain diffusion parameters. A PLS approach was applied to reveal the diffusion parameter patterns responsible for the cognitive dysfunction. RESULTS: The first latent variable (LV) was mainly associated with demyelination, while the second and third explained axonal damage. While the first two LV represented mainly Brief Visuospatial Memory Test (BVMT) and Single Digit Modality Test (SDMT), the third LV depicted diffusion alterations mainly the verbal subtest. The first LVs spatial map showed demyelination in the corpus callosum. The second LVs spatial map showed the diffusion alterations in the thalamus. The third LV depicted diffusion alterations in the putative left superior longitudinal fascicle. CONCLUSION: Visual memory demanding tasks versus language functions depend on distinct patterns of diffusion parameters and the spatial organisation. Axial diffusivity alterations, a putative marker of irreversible axonal loss explained around 20% of variability in the cognitive functions.

Systemic BCG-Osis as a Rare Side Effect of Intravesical BCG Treatment for Superficial Bladder Cancer.

Intravesical Bacilli Calmette-Guérin (BCG) immunotherapy is a commonly used treatment for superficial bladder cancer. Although the treatment is well tolerated in 95% of cases, life-threatening side effects including BCG sepsis can occur. This report describes the case of an 82-year-old man with a background of lung disease. He developed septic shock and type two respiratory failure after receiving the sixth installation of intravesical BCG (TICE strain) immunotherapy for recurrent bladder Transitional Cell Carcinoma in situ. Despite the early initiation of broad spectrum antibiotics (tazocin and gentamicin), he remained pyrexial. There was a rapid deterioration, and on the second day of his admission, he developed type two respiratory failure secondary to Acute Respiratory Distress Syndrome (ARDS) prompting transfer to Intensive Care for Bilevel Positive Airway Pressure (BiPAP) Ventilation. The blood cultures taken before the induction of antibiotics results were negative. Increasing clinical suspicion of systemic BCG-osis prompted the initiation of antituberculosis therapy (ethambutol, isoniazid rifampicin) and steroids. Following six days of BiPAP and anti-tuberculosis therapy in ITU, his condition started to improve. Following a prolonged hospital stay he was discharged on long term ethambutol therapy. BCG-osis is a well-known though rare side effect of intravesical BCG therapy. We would like to highlight the importance of having a low threshold for starting anti-TB treatment.

Evaluation of water quality threats to the endangered Okaloosa darter (Etheostoma okaloosae) in East Turkey Creek on Eglin Air Force Base.

The threatened Okaloosa darter (Etheostoma okaloosae) is found almost exclusively on the Eglin Air Force Base in the Choctawhatchee Bay watershed of Florida. Portions of this limited habitat are threatened with soil erosion, altered hydrology, and impaired water quality. In the present study, general water quality parameters (i.e., dissolved oxygen, specific conductance, pH, temperature, relative turbidity, and primary productivity) were characterized in East Turkey Creek, which is a body of water potentially impacted by treated wastewater sprayfields, and Long Creek, an adjacent reference stream that does not border the sprayfields. Water quality was assessed during a 30-day exposure using passive samplers for both non-polar and polar effluent parameters. Because the Okaloosa darter was listed as endangered at the time of sampling we chose a closely related species from the same creeks, the sailfin shiner (Pteronotropis hypseleotris) in which to measure metal body burdens. Additionally, fathead minnows (Pimephales promelas) were used for microarray analysis on gonad and liver tissues after 48 h exposures to water collected from the two creeks and brought into the laboratory. Waters from all sites, including reference sites, affected the expression of genes related to various biological processes including transcription and translation, cell cycle control, metabolism, and signaling pathways, suggesting that the sum of anthropogenic compounds in the site waters may cause a generalized stress response in both liver and testis, an effect that could be related to the generally low populations of the Okaloosa darter. Furthermore, effects of site waters on fish gene expression may be related to the impact of human activities other than the wastewater sprayfields, as nearby areas are closed to the public for military testing, training, and administrative activities and due to ordnance contamination.

Rare association of anti-hu antibody positive paraneoplastic neurological syndrome and transitional cell bladder carcinoma.

Introduction. Paraneoplastic encephalomyelitis (PEM) and subacute sensory neuronopathy (SSN) are remote effects of cancer, usually associated with small-cell lung carcinoma and positive anti-Hu antibody. We describe the rare association of bladder transitional cell carcinoma (TCC) with anti-Hu antibody positivity resulting in this paraneoplastic neurological syndrome. Patient. A 76-year-old female presented with bilateral muscle weakness and paraesthesia of the upper and lower limbs in a length-dependent "glove and stocking" distribution. Central nervous system symptoms included cognitive problems, personality change, and truncal ataxia. Case notes and the literature were reviewed. Result. Autoantibody screening was positive for anti-Hu antibody (recently renamed antineuronal nuclear antibody 1, ANNA-1). The diagnosis of PEM and SSN was supported by MRI and lumbar puncture results. A superficial bladder TCC was demonstrated on CT and subsequently confirmed on histology. No other primary neoplasm was found on full-body imaging. The neurological symptoms were considered to be an antibody-mediated paraneoplastic neurological syndrome and improved after resection of the tumour. Discussion. The association of anti-Hu positive paraneoplastic neurological syndrome and TCC has not been described in the literature previously. We emphasize the need for detailed clinical examination and the importance of a multidisciplinary thought process and encourage further awareness of this rare association.

Pharmacokinetics and preliminary safety evaluation of azithromycin in adult horses.

Azithromycin is widely used in foals but has not been studied in adult horses. The goals of this study were to determine the pharmacokinetic profile and to make a preliminary assessment of the safety of azithromycin in adult horses. Azithromycin was administered intravenously (5 mg/kg) and intragastrically (10 mg/kg) to six healthy mares in a crossover design. Serial plasma samples, blood neutrophils, and pulmonary macrophages were collected for the measurement of azithromycin concentrations. Azithromycin was also administered orally (10 mg/kg) once a day for 5 days to five healthy mares for preliminary evaluation of safety in adult horses. The bioavailability of azithromycin following intragastric administration was 45 ± 12%. Concentrations within peripheral neutrophils and bronchoalveolar macrophages were several fold higher than that of plasma. Mild decreases in appetite (n = 3) and alterations in fecal consistency (n = 3) were noted following repeated oral administration. The pharmacokinetic profiles of azithromycin in adult horses, especially the slow elimination rate and intraneutrophil and intrapulmonary macrophage accumulation, demonstrate that it is conducive to use in this age group. Because of the gastrointestinal alterations noted, further studies are warranted before azithromycin can be recommended for use in adult horses.

An interlaboratory study of the pharmacokinetics of testosterone following intramuscular administration to Thoroughbred horses.

Testosterone is an anabolic androgenic steroid (AAS) that is endogenously produced by both male and female horses that also has the potential for abuse when administered exogenously to race horses. To recommend appropriate withdrawal guidelines so that veterinarians can discontinue therapeutic use prior to competition, the pharmacokinetics and elimination of testosterone were investigated. An aqueous testosterone suspension was administered intramuscularly in the neck of Thoroughbred horses (n = 20). The disposition of testosterone from this formulation was characterized by an initial, rapid absorption phase followed by a much more variable secondary absorption phase. The median terminal half-life was 39 h. A second focus of this study was to compare the testosterone concentrations determined by two different laboratories using a percentage similarity model with a coefficient of variation of 16.5% showing good agreement between the two laboratories results. Based on the results of this study, a withdrawal period of 30 days for aqueous testosterone administered IM is recommended.

The effect of sildenafil citrate administration on selected physiological parameters of exercising Thoroughbred horses.

REASONS FOR PERFORMING STUDY: Sildenafil, a phosphodiesterase-5 inhibitor vasodilator, increases cGMP concentrations by inhibiting enzymatic degradation. Marketed to treat erectile dysfunction in men, it also reduces pulmonary arterial pressure (PAP). Because it reduces PAP, sildenafil may enhance performance and/or prevent exercise induced-pulmonary haemorrhage (EIPH). OBJECTIVE: To determine if sildenafil citrate administration altered commonly measured indices of performance or reduced EIPH in exercised horses. METHODS: Thirteen athletically conditioned Thoroughbred horses (2 mares and 11 geldings, age 3-12 years) were administered sildenafil citrate or placebo in 2 crossover design exercise testing studies. In a step-wise test to exhaustion, inspired/expired gas analysis, blood lactate, heart rate, runtime and bronchoalveolar lavage (BAL) cytology were measured. In a 13 m/s test to exhaustion, blood lactate, heart rate, runtime, BAL cytology and pulmonary arterial pressure were measured. Data were analysed with paired and unpaired t tests, one-way ANOVA and Tukey's pair-wise multiple comparison and Friedman repeated measure analysis of variance on ranks. RESULTS: The administration of sildenafil did not alter mean inspired/expired gas measurements, plasma lactate concentrations or acute pulmonary haemorrhage in either exercise test or pulmonary arterial pressure measurement in the 13 m/s trial. Heart rates in both stress tests were significantly different at submaximal speeds and during the early recovery period. Run time was not affected by sildenafil administration in the step-wise trial (P = 0.622) or in the 13 m/s trial (P = 0.059). CONCLUSIONS: Sildenafil did not alleviate pulmonary haemorrhage or enhance performance-related indices in these trials. Sildenafil administration altered cardiovascular adaptation to intense exercise as evidenced by altered heart rates at submaximal speeds and post exercise. The effect of these alterations on other performance perimeters was not evident.

Association of idiopathic inflammatory myopathy and Crohn's disease.

We describe a rare case of concurrent polymyositis and Crohn's disease in a female patient. A 69-year-old female presented in December 2007 with a 5-month history of proximal muscle weakness, pain, fatigue and difficulty in walking and swallowing. Blood tests revealed elevated creatine kinase (3,429 U/l) and lactate dehydrogenase (2,013 U/l) levels. Magnetic resonance imaging found lumbar disc protrusion. Review by immunologists showed a diagnosis of idiopathic inflammatory myopathy. Though electromyography and muscle biopsy at this point were non-specific, corticosteroid treatment was commenced. Her condition worsened precipitously leading to hospitalisation under immunologists. As the provisional diagnosis was polymyositis, we commenced 1.5 mg/kg per day corticosteroid but her muscle power did not improve. Recurrent abdominal symptoms lead to ultrasonography showing intestinal inflammation. While tumour markers were elevated, thorough investigation failed to identify a tumour. Corticosteroid therapy was continued. Persistent abdominal symptoms lead to repeat colonoscopy and biopsy confirming Crohn's disease. Repeat electromyography and muscle biopsy confirmed the diagnosis of polymyositis. Her corticosteroids were tapered off and 5-aminosalicylic acid and azathioprine were started. Her myositic symptoms gradually abated with improvement in her Crohn's disease. She is now able to walk independently and takes 8 mg/day corticosteroids and her muscle enzyme levels are normal. Remember rare systemic associations when dealing with immune-mediated disease. Consider myositis in the differential diagnosis of Crohn's disease associated myopathy. Treating Crohn's disease may lead to improvement in steroid-resistant myositis where the two are associated.

Functional and morphological evaluation of hand microcirculation with nailfold capillaroscopy and laser Doppler imaging in Raynaud's and Sjögren's syndrome and poly/dermatomyositis.

OBJECTIVES: Nailfold capillaroscopy is widely used in autoimmune patients to determine capillary morphology. Laser Doppler imaging (LDI) is a relatively new method for measuring the microcirculation of cutaneous perfusion. The aim of this study was to investigate the capillary morphology and microcirculation among patients with Sjögren's syndrome (SS) and poly/dermatomyositis (PM/DM) with these two non-invasive methods and to detect secondary Raynaud's syndrome (SRS) in these autoimmune diseases. METHODS: Thirty patients with primary SS, 30 patients with PM/DM, 30 patients with primary Raynaud's syndrome (PRS), and 30 healthy volunteers were included in the study. Nailfold capillaroscopy and LDI were performed on each patient. RESULTS: A comprehensive analysis was performed among the patients and healthy individuals. Among SS patients avascularity and among PM/DM patients avascularity and capillary morphology changes were most often detected by capillaroscopy. With LDI the mean steady-state cutaneous perfusion was 1.25 perfusion units (PU) in region of interest 1 (ROI1), 1.22 in ROI2, and 1.49 at the fingertips in PRS patients; the corresponding values were 1.2, 1.03, and 1.48 PU in SS, 0.91, 0.76, and 1.19 PU in PM/DM, and 1.79, 1.62, and 2.2 PU in the controls. The differences were significant between each autoimmune group compared to the control group (p<0.02, p<0.001, and p<0.001, respectively). CONCLUSIONS: By using nailfold capillaroscopy, abnormalities in capillary morphology can be detected, and by using LDI, the reduced blood flow in the capillaries can be detected. These investigations can be useful in the detection of SRS, or in distinguishing whether the reduced blood flow is due to primary/systemic autoimmune diseases.

Comparison between omega-3 and omega-6 polyunsaturated fatty acid intakes as assessed by a food frequency questionnaire and erythrocyte membrane fatty acid composition in young children.

OBJECTIVE: We conducted a dietary validation study in youth aged 1-11 years by comparing dietary intake of omega-3 and omega-6 polyunsaturated fatty acids (PUFAs) as assessed by a parent-completed semiquantitative food frequency questionnaire (FFQ) over time to erythrocyte membrane composition of the same fatty acids. DESIGN: The study population included youth aged 1-11 years who were participants in the Diabetes Autoimmunity Study in the Young (DAISY), a longitudinal study in Denver, Colorado that is following a cohort of youth at risk for developing type I diabetes. Four hundred and four children who had erythrocyte membrane fatty acid data matched to an FFQ corresponding to the same time frame for a total of 917 visits (matches) were included. PUFA intake was expressed both as g/day (adjusted for total energy) and as percent of total fat intake. We used mixed models to test the association and calculate the correlation between the erythrocyte membrane estimates and PUFA intake using all records of data for each youth. RESULTS: Intakes of total omega-3 fatty acids (beta=0.52, P<0.0001, rho=0.23) and marine PUFAs (beta=1.62, P<0.0001, rho=0.42), as a percent of total fat in the diet, were associated with percent of omega-3 and marine PUFAs in the erythrocyte membrane. Intakes of omega-6 PUFAs (beta=0.04, P=0.418, rho=0.05) and arachidonic acid (beta=0.31, P=0.774, rho=0.01) were not associated. CONCLUSIONS: In these young children, an FFQ using parental report provided estimates of average long-term intakes of marine PUFAs that correlated well with their erythrocyte cell membrane fatty acid status.

Raynaud's syndrome: comparison of late and early onset forms using hand perfusion scintigraphy.

Primary Raynaud's disease is generally a disease of younger females; however, there are cases where symptoms present over the age of 40. These cases are described as late onset. In our current prospective study we compared the characteristics of early and late onset types of primary Raynaud's in 127 patients. In addition to the collection of medical records, we performed capillary-microscopy and hand perfusion scintigraphy using Tc-99 m DTPA to evaluate the microcirculation of each patient's fingers. Regarding the spectrum of the capillary-microscopic findings, we did not find any significant difference between the early and late onset forms. However, in hand perfusion examinations done using Tc-99 m DTPA, we measured a significantly lower finger/palm ratio (FPR) in the early onset group of patients. We also observed a correlation between the duration of the disease and the FPR, as well as between the age and FPR. Longer disease duration resulted in a significantly lower FPR. On the basis of our results, we believe that late onset Raynaud's should be treated as a separate entity. Due to its different characteristics found on examination and follow-up of our patients, functional hand perfusion examination should be recommended independently of the age-related characteristics of the disease.

Organochlorine concentrations in bonnethead sharks (Sphyrna tiburo) from Four Florida Estuaries.

Because of their persistence in aquatic environments and ability to impair reproduction and other critical physiological processes, organochlorine (OC) contaminants pose significant health risks to marine organisms. Despite such concerns, few studies have investigated levels of OC exposure in sharks, which are fish particularly threatened by anthropogenic pollution because of their tendency to bioaccumulate and biomagnify environmental contaminants. The present study examined concentrations of 29 OC pesticides and total polychlorinated biphenyls (PCBs) in the bonnethead shark (Sphyrna tiburo), an abundant species for which evidence of reproductive impairment has been observed in certain Florida populations. Quantifiable levels of PCBs and 22 OC pesticides were detected via gas chromatography and mass spectrometry in liver of 95 S. tiburo from four estuaries on Florida's Gulf coast: Apalachicola Bay, Tampa Bay, Florida Bay, and Charlotte Harbor. In general, OC concentrations were significantly higher in Apalachicola Bay, Tampa Bay, and Charlotte Harbor S. tiburo in relation to the Florida Bay population. Because the rate of infertility has been shown to be dramatically higher in Tampa Bay versus Florida Bay S. tiburo, the present findings allude to a possible relationship between OC exposure and reproductive health that requires further investigation. Pesticide and PCB concentrations did not appear to significantly increase with growth or age in S. tiburo, suggesting limited potential for OC bioaccumulation in this species compared with other sharks for which contaminant data are available. Concentrations of OCs in serum and muscle were not correlated with those in liver, indicating that these tissues are poor surrogates for measuring internal OC burden in this species via nonlethal sampling procedures.

Molecular characterization of rifampin-resistant isolates of Mycobacterium tuberculosis from Hungary by DNA sequencing and the line probe assay.

Two regions of rpoB associated with rifampin resistance were sequenced in 29 rifampin-resistant (determined by the proportion method) isolates of Mycobacterium tuberculosis obtained from patients from three counties in Hungary. Of the 29 resistant strains, 27 had a mutation in either the 81-bp region (26 strains) or the N-terminal region (1 strain), while the other 2 strains had no mutations in either region. The locations and frequencies of the mutations differed from those previously reported. The most common mutation in this study, D516V, was found in 38% of the Hungarian strains, a frequency 2 to 10 times higher than that found in studies from other countries. These same 29 isolates were also evaluated with the Inno-LiPA Rif. TB test (LiPA), a reverse hybridization assay for the rapid detection of rifampin resistance. Although LiPA detected the presence of an rpoB mutation in 26 of the resistant isolates, the type of mutation could not be determined in 4 isolates because the mutations present were not among those included on the LiPA strip. In addition, a silent mutation in one of the rifampin-susceptible control strains was interpreted as rifampin resistant by LiPA. These findings demonstrate the importance of validating this rapid molecular test by comparison with DNA sequence results in each geographic location before incorporating the test into routine diagnostic work.

Lead content of calcium supplements.

CONTEXT: Substantial quantities of lead have been reported in some over-the-counter calcium supplement preparations, including not only bone-meal and dolomite, but also over-the-counter natural and refined calcium carbonate formulations. Examination of this issue is warranted given recent increases in physician recommendations for calcium supplements for prevention and treatment of osteoporosis. OBJECTIVES: To determine the lead content of calcium supplements and to quantify the lead exposure from popular brands of calcium in dosages used for childhood recommended daily allowance, osteoporosis, and phosphate binding in dialysis patients. DESIGN AND SETTING: Analysis of lead content in 21 formulations of nonprescription calcium carbonate (including 7 natural [ie, oyster shell] and 14 refined), 1 brand of prescription-only calcium acetate, and 1 noncalcium synthetic phosphate binder conducted in March 2000. MAIN OUTCOME MEASURES: Lead content, assayed using electrothermal atomic absorption, expressed as micrograms of lead per 800 mg/d of elemental calcium, per 1500 mg/d of calcium, and for a range of dosages for patients with renal failure. Six microg/d of lead was considered the absolute dietary limit, with no more than 1 microg/d being the goal for supplements. RESULTS: Four of 7 natural products had measurable lead content, amounting to approximately 1 microg/d for 800 mg/d of calcium, between 1 and 2 microg/d for 1500 mg/d of calcium, and up to 10 microg/d for renal dosages. Four of the 14 refined products had similar lead content, including up to 3 microg/d of lead in osteoporosis calcium dosages and up to 20 microg/d in high renal dosages. No lead was detected in the calcium acetate or polymer products. Lead was present even in some brand name products from major pharmaceutical companies not of natural oyster shell derivation. CONCLUSIONS: Despite increasingly stringent limits of lead exposure, many calcium supplement formulations contain lead and thereby may pose an easily avoidable public health concern. JAMA. 2000;284:1425-1429.

Surface-enhanced Raman scattering from an etched polymer substrate.

An etched polymer was evaluated as a substrate suitable for routine SER analysis and was found to perform similarly to crossed gratings and posted quartz wafers. Silver particles were layered onto sheets of etched poly(ethylene terephthalate) by chemical reduction, sputtering, and vapor deposition. Enhancement factors ranged from 10(4) to >10(5) for crystal violet on chemically reduced and sputtered surfaces, respectively. Ranges of linearity up to 3 orders of magnitude were attained with limits of detection of ∼5 pg. The variability of response was <20% RSD for both routinely and painstakingly prepared samples. To induce enhancements beyond those possible from the dry substrate, a thin film of water was held on the analyte-treated substrate surface in a liquid state. Typical spectra of nine analytes with amino, carboxylate, and/or nitro groups were collected from the most active substrate.

Value of repeated analyses of 24-hour urine in recurrent calcium urolithiasis.

OBJECTIVES: The value of repeated analyses of 24-hour urine collections for daily excretion of calcium, uric acid, citrate, phosphorus, and creatinine and for volume and pH performed to detect and classify metabolic disorders in a selected group of calcium stone formers with striking recurrence rates was assessed in a retrospective study. METHODS: A total of 441 urinalyses made over a mean period of 80.4 months of samples obtained from 49 patients were reviewed. Fifty-nine percent of patients were initially found to have metabolic disorders (absorptive hypercalciuria types I and II, hyperuricuria, hypocitraturia) and therefore received specific drug therapy (allopurinol, thiazide, alkali citrate, orthophosphate) for a mean of 45.7 months (group I). The remaining patients were classified as metabolically inactive and were given general metaphylactic instructions (group II). RESULTS: In 73% of patients recurrent stones developed, with no statistically significant difference between the two groups (79% vs 65%). In 55% of group I patients, urinalyses continued to yield abnormal findings during follow-up; however, subsequent abnormal findings were also seen in 40% of the metabolically inactive group II patients. Overall, metabolic disorders were observed at some point in 75% of patients. Only 27% remained recurrence free, and 62% thereof also had pathologic urinary findings. CONCLUSIONS: It does not appear that drug treatment in recurrent calcium urolithiasis based on urinary findings is superior to simple general metaphylactic recommendations, nor that repeated analyses of 24-hour urine collections furnish additional information on the risk of recurrent stone formation or on the presence of risk factors leading to recurrence in the long-term course of disease.