bluuebunny/crossref_metadata_2025 huggingface dataset:
Subsurface Transport of Phosphorus in Riparian Floodplains: Influence of Preferential Flow Paths
Authors: Fuchs John W. , Fox Garey A. , Storm Daniel E. , Penn Chad J. , Brown Glenn O.
Published: February 2009

For phosphorus (P) transport from upland areas to surface water systems, the primary transport mechanism is typically considered to be surface runoff with subsurface transport assumed negligible. However, certain local conditions can lead to an environment where subsurface transport may be significant. The objective of this research was to determine the potential of subsurface transport of P along streams characterized by cherty or gravel subsoils, especially the impact of preferential flow paths on P transport. At a field site along the Barren Fork Creek in northeastern Oklahoma, a trench was installed with the bottom at the topsoil/alluvial gravel interface. Fifteen piezometers were installed surrounding the trench to monitor flow and transport. In three experiments, water was pumped into the trench from the Barren Fork Creek to maintain a constant head. At the same time, a conservative tracer (Rhodamine WT) and/or potassium phosphate solution were injected into the trench at concentrations at 3 and 100 mg/L for Rhodamine WT and at 100 mg/L for P. Laboratory flow‐cell experiments were also conducted on soil material <2 mm in size to determine the effect that flow velocity had on P sorption. Rhodamine WT and P were detected in some piezometers at equivalent concentrations as measured in the trench, suggesting the presence of preferential flow pathways and heterogeneous interaction between streams and subsurface transport pathways, even in nonstructured, coarse gravel soils. Phosphorus transport was retarded in nonpreferential flow paths. Breakthrough times were approximately equivalent for Rhodamine WT and P suggesting no colloidal‐facilitated P transport. Results from laboratory flow‐cell experiments suggested that higher velocity resulted in less P sorption for the alluvial subsoil. Therefore, differences in flow rates between preferential and nonpreferential flow pathways in the field led to variable sorption. The potential for nutrient subsurface transport shown by this alluvial system has implications regarding management of similar riparian floodplain systems.
Energy Use and Carbon Dioxide Emissions from Cropland Production in the United States, 1990–2004
Authors: Nelson Richard G. , Hellwinckel Chad M. , Brandt Craig C. , West Tristram O. , De La Torre Ugarte Daniel G. , Marland Gregg
Published: February 2009

Changes in cropland production and management influence energy consumption and emissions of CO2 from fossil‐fuel combustion. A method was developed to calculate on‐site and off‐site energy and CO2 emissions for cropping practices in the United States at the county scale. Energy consumption and emissions occur on‐site from the operation of farm machinery and occur off‐site from the manufacture and transport of cropland production inputs, such as fertilizers, pesticides, and agricultural lime. Estimates of fossil‐fuel consumption and associated CO2 emissions for cropping practices enable (i) the monitoring of energy and emissions with changes in land management and (ii) the calculation and balancing of regional and national carbon budgets. Results indicate on‐site energy use and total energy use (i.e., the sum of on‐site and off‐site) on U.S. croplands in 2004 ranged from 1.6 to 7.9 GJ ha−1 yr−1 and from 5.5 to 20.5 GJ ha−1 yr−1, respectively. On‐site and total CO2 emissions in 2004 ranged from 23 to 176 kg C ha−1 yr−1 and from 91 to 365 kg C ha−1 yr−1, respectively. During the period of this analysis (1990–2004), national total energy consumption for crop production ranged from 1204 to 1297 PJ yr−1 (Petajoule = 1 × 1015 Joule) with associated total fossil CO2 emissions ranging from 21.5 to 23.2 Tg C yr−1 (Teragram = 1 × 1012 gram). The annual proportion of on‐site CO2 to total CO2 emissions changed depending on the diversity of crops planted. Adoption of reduced tillage practices in the United States from 1990 to 2004 resulted in a net fossil emissions reduction of 2.4 Tg C.
Geoarchaeology of a Strath Terrace in the Upper Ohio Valley, West Virginia
Authors: Cremeens D. L. , Lothrop J. C.
Published: February 2009

Soil characterization and distribution on a narrow ridge strath terrace bordering the Ohio River in the northern panhandle of West Virginia was evaluated to determine the stratigraphic context of the cultural remains of two prehistoric archaeological sites. Five soil map units were delineated in the project area based on the distribution of regolith materials and associated soil characteristics. Shale and sandstone residuum in the central crest of the ridge is covered with a laterally discontinuous mantle of Pleistocene alluvium, 0.25 to >1.2 m thick, and a continuous mantle of Late Pleistocene loess, 0.25 to 1.1 m thick. Hapludalfs formed in the loess over alluvium, or in loess over residuum, indicate moderate to long‐term (e.g., 12,000 yr) pedogenesis. On steep shoulder slopes, Dystrudepts in shallow residuum with little to no loess indicate limited pedogenesis and possible early to mid‐Holocene erosion. Panhandle Archaic inhabitants of Site 46Br31 (∼6090–3400 yr BP) harvested freshwater mussels from the Ohio River below the ridge, and after consumption discarded the shells on the shoulder slopes at the southern end of the ridge. The resultant shell middens, largely disturbed by 20th century relic hunters, form a complex map unit of Dystrudepts and Udorthents. The distribution of soils on this ridge and the associated archaeological remains indicate that the successive occupations of prehistoric Native American inhabitants lived on the same ground surface. The resultant cultural remains were not buried or stratigraphically separated. The modern soil surface is an approximate, although eroded, remnant of the occupied ground surface. The vertical distribution of artifacts reflects several millennia on a mature soil surface with an evolving biomantle.
Liquid Behavior in Partially Saturated Porous Media under Variable Gravity
Authors: Or Dani , Tuller Markus , Jones Scott B.
Published: February 2009

Plant growth in restricted volumes of porous material is of interest for advanced life support systems for the National Aeronautics and Space Administration's future space missions. Reduced gravity conditions may affect fluid behavior in partially saturated porous media, requiring special considerations for growth media selection and root module design to ensure reliable water, air, and nutrient supply. Evidence suggests that fluid displacement patterns become unstable and enhance phase entrapment in the absence of gravity, thereby modifying macroscopic transport properties essential for fluid management decisions. Parabolic flight experiments have shown that preferential flows may lead to phase (air or gas) entrapment that would affect gaseous diffusion, as illustrated by lattice Boltzmann simulations. In microgravity, unstable flow patterns and particle rearrangement introduce uncertainty associated with particulate root growth media. These findings suggest that future efforts toward designing porous media and plant root modules in reduced gravity should focus on engineered plant growth media with stable pore space and spatially segregated domains that support water and nutrient retention in addition to gas exchange.
The Clash of Globalizations in the Middle East
Authors: Henry Clement M.
Published: February 2009

Globalization connotes the removal of barriers between states to the movement of capital, goods and labor. While the lowering of barriers to the movement of factors of production has resulted in transnational networks of production and elements of an international civil society, it has also facilitated international terrorist networks, drug cartels and the like. In the Middle East, for strategic reasons discussed in this paper, the spectrum of barriers to be removed includes not just protectionist trade or monetary policies but the regimes as well. Regime change can be brutal or gradual, imposed or developed from within. This paper examines the sorts of political change envisaged by the authors of the Arab Human Development Report 2002 to overcome the regions freedom deficit as well as the darker, by now all too familiar, scenarios associating this dimension of globalization regime changewith American (multilateral or unilateral) military operations. The Middle East is home to most of the oil that fueled the worlds first truly global industry, but the region may also become the epicenter of forces that reverse the globalizing tendencies of states.
Water Scarcity and Food Imports: An Emperical Investigation of the 'Virtual Water' Hypothesis in the MENA Region
Authors: Hakimian Hassan
Published: February 2009

Despite the long tradition established by the HeckscherOhlin (HO) theorem and copious literature on the so-called Leontief Paradox, economists have not methodically linked the Middle East and North Africa (MENA) regions well-known water-scarcity problem to its mounting food imports. This paper first reinterprets the factor endowments and comparative advantage theory in the MENA context, suggesting that the virtual water (VW) hypothesis, focusing on water embedded in commodities, is in line with the HO models tenet that trade in commodities is an indirect way of trade in factors of production. Second, findings using comparative cross-section regression analysis for 100 countries appear to vindicate the VW hypothesis that the import structures for water-deficit areas are dominated by large food/agricultural imports. The study ends with a discussion of the policy and political economy implications of the hypothesis in the light of our empirical findings.
Sex Hormone–Binding Globulin Levels Predict Insulin Sensitivity, Disposition Index, and Cardiovascular Risk During Puberty
Authors: Sørensen Kaspar , Aksglaede Lise , Munch-Andersen Thor , Aachmann-Andersen Niels Jacob , Petersen Joergen Holm , Hilsted Linda , Helge Jørn Wulff , Juul Anders
Published: February 2009

OBJECTIVE

Early puberty is associated with increased risk of subsequent cardiovascular disease. Low sex hormone–binding globulin (SHBG) levels are a feature of early puberty and of conditions associated with increased cardiovascular risk. The aim of the present study was to evaluate SHBG as a predictor of glucose metabolism and metabolic risk during puberty.

RESEARCH DESIGN AND METHODS

This was a cross-sectional study on 132 healthy Caucasian children and adolescents evaluated by an oral glucose tolerance test, a dual-energy X-ray absorptiometry scan, direct oxygen uptake measurement during cycle ergometry, and fasting blood samples.

RESULTS

SHBG levels declined with advancement of puberty in both boys (P < 0.001) and girls (P = 0.019). SHBG was significantly positively associated with insulin sensitivity in boys (P < 0.001) and girls (P < 0.001). In addition, SHBG was a strong predictor of insulin sensitivity (P = 0.001) and the only predictor of the disposition index (P = 0.031) after adjustment for puberty, fat mass, and aerobic fitness. SHBG was significantly negatively associated with metabolic risk (P = 0.032) and with hypersensitive C-reactive protein levels (P = 0.030) after adjustment for relevant confounders.

CONCLUSIONS

SHBG was a strong predictor of insulin sensitivity and metabolic risk during puberty. Thus, we hypothesize that SHBG integrates the marked changes in glucose metabolism and body composition that occur during the pubertal transition.
Pulse Pressure and Prediction of Incident Foot Ulcers in Type 2 Diabetes
Authors: Monami Matteo , Vivarelli Maria , Desideri Carla Maria , Colombi Claudia , Marchionni Niccolò , Mannucci Edoardo
Published: February 2009

OBJECTIVE

To assess the relevance of pulse pressure as a predictor of foot ulcers in type 2 diabetic subjects.

RESEARCH DESIGN AND METHODS

A cohort study was performed on a consecutive series of 1,945 type 2 diabetic outpatients without a foot ulcer at baseline. Incident foot ulcers were identified through the regional hospital discharge system, which contains ICD codes of current diagnoses.

RESULTS

During a follow-up of mean ± SD 4.2 ± 2.2 years, 86 ulcers were observed. After adjusting for confounders, the highest quartiles of pulse pressure had a 2.39-fold (95% CI 1.14–5.02) risk of foot ulcers. When ischemic ulcers were considered separately, the highest pulse pressure quartile was associated with an increased age- and sex-adjusted risk (2.08 [95% CI 1.02–4.24]), whereas no increase of risk was observed for neuropathic ulcers.

CONCLUSIONS

Elevated pulse pressure represents an independent predictor of foot ulcers in diabetic patients; this parameter should be considered for the stratification of risk of ischemic or neuroischemic ulcers.
Elevated A1C in Adults Without a History of Diabetes in the U.S.
Authors: Selvin Elizabeth , Zhu Hong , Brancati Frederick L.
Published: February 2009

OBJECTIVE

The purpose of this study was to examine the prevalence and correlates of elevated A1C in a large, nationally representative sample of adults without diabetes in the U.S.

RESEARCH DESIGN AND METHODS

We analyzed data from 15,934 participants aged ≥20 years without diagnosed diabetes who had A1C measurements in the 1999–2006 National Health and Nutrition Examination Survey, a cross-sectional and nationally representative sample of the U.S. population.

RESULTS

The overall prevalence of A1C >6% was 3.8%, corresponding to 7.1 million adults without diabetes in the U.S. population. Approximately 90% of these individuals had fasting glucose ≥100 mg/dl. Older age, male sex, non-Hispanic black race/ethnicity, hypercholesterolemia, higher BMI, and lower attained education were significantly associated with having a higher A1C level even among individuals with normal fasting glucose (<100 mg/dl) and after multivariable adjustment.

CONCLUSIONS

A single elevated A1C level (A1C >6%) is common in the general population of adults without a history of diabetes and is highly reliable for the detection of elevated fasting glucose. Nondiabetic adults with elevated A1C are likely to have impaired fasting glucose and an array of other risk factors for type 2 diabetes and cardiovascular disease.
Predictors of Development of Diabetes in Patients With Chronic Heart Failure in the Candesartan in Heart Failure Assessment of Reduction in Mortality and Morbidity (CHARM) Program
Authors: Preiss David , Zetterstrand Sofia , McMurray John J.V. , Östergren Jan , Michelson Eric L. , Granger Christopher B. , Yusuf Salim , Swedberg Karl , Pfeffer Marc A. , Gerstein Hertzel C. , Sattar Naveed ,   for the Candesartan in Heart Failure Assessment of Reduction in Mortality and Morbidity Investigators
Published: February 2009

OBJECTIVE

The purpose of this study was to identify predictors of incident diabetes during follow-up of nondiabetic patients with chronic heart failure (CHF) in the Candesartan in Heart Failure Assessment of Reduction in Mortality and Morbidity (CHARM) program.

RESEARCH DESIGN AND METHODS

A total of 1,620 nondiabetic patients had full baseline datasets. We compared baseline demographic, medication, and laboratory data for patients who did or did not develop diabetes and conducted logistic regression and receiver operator characteristic curve analyses.

RESULTS

Over a median period of 2.8 years, 126 of the 1,620 patients (7.8%) developed diabetes. In multiple logistic regression analysis, the following baseline characteristics were independently associated with incident diabetes in decreasing order of significance by stepwise selection: higher A1C (odds ratio [OR] 1.78 per 1 SD increase; P < 0.0001), higher BMI (OR 1.64 per 1 SD increase; P < 0.0001), lipid-lowering therapy (OR 2.05; P = 0.0005), lower serum creatinine concentration (OR 0.68 per 1 SD increase; P = 0.0018), diuretic therapy (OR 4.81; P = 0.003), digoxin therapy (OR 1.65; P = 0.022), higher serum alanine aminotransferase concentration (OR 1.15 per 1 SD increase; P = 0.027), and lower age (OR 0.81 per 1 SD increase; P = 0.048). Using receiver operating characteristic curve analysis, A1C and BMI yielded areas under the curve of 0.723 and 0.712, respectively, increasing to 0.788 when combined. Addition of other variables independently associated with diabetes risk minimally improved prediction of diabetes.

CONCLUSIONS

In nondiabetic patients with CHF in CHARM, A1C and BMI were the strongest predictors of the development of diabetes. Other minor predictors in part reflected CHF severity or drug-associated diabetes risk. Identifying patients with CHF at risk of diabetes through simple criteria appears possible and could enable targeted preventative measures.
One-Year Treatment With Exenatide Improves β-Cell Function, Compared With Insulin Glargine, in Metformin-Treated Type 2 Diabetic Patients
Authors: Bunck Mathijs C. , Diamant Michaela , Cornér Anja , Eliasson Bjorn , Malloy Jaret L. , Shaginian Rimma M. , Deng Wei , Kendall David M. , Taskinen Marja-Riitta , Smith Ulf , Yki-Järvinen Hannele , Heine Robert J.
Published: February 2009

OBJECTIVE

Traditional blood glucose–lowering agents do not sustain adequate glycemic control in most type 2 diabetic patients. Preclinical studies with exenatide have suggested sustained improvements in β-cell function. We investigated the effects of 52 weeks of treatment with exenatide or insulin glargine followed by an off-drug period on hyperglycemic clamp–derived measures of β-cell function, glycemic control, and body weight.

RESEARCH DESIGN AND METHODS

Sixty-nine metformin-treated patients with type 2 diabetes were randomly assigned to exenatide (n = 36) or insulin glargine (n = 33). β-Cell function was measured during an arginine-stimulated hyperglycemic clamp at week 0, at week 52, and after a 4-week off-drug period. Additional end points included effects on glycemic control, body weight, and safety.

RESULTS

Treatment-induced change in combined glucose- and arginine-stimulated C-peptide secretion was 2.46-fold (95% CI 2.09–2.90, P < 0.0001) greater after a 52-week exenatide treatment compared with insulin glargine treatment. Both exenatide and insulin glargine reduced A1C similarly: −0.8 ± 0.1 and −0.7 ± 0.2%, respectively (P = 0.55). Exenatide reduced body weight compared with insulin glargine (difference −4.6 kg, P < 0.0001). β-Cell function measures returned to pretreatment values in both groups after a 4-week off-drug period. A1C and body weight rose to pretreatment values 12 weeks after discontinuation of either exenatide or insulin glargine therapy.

CONCLUSIONS

Exenatide significantly improves β-cell function during 1 year of treatment compared with titrated insulin glargine. After cessation of both exenatide and insulin glargine therapy, β-cell function and glycemic control returned to pretreatment values, suggesting that ongoing treatment is necessary to maintain the beneficial effects of either therapy.
Comparison of Three Protocols for Tight Glycemic Control in Cardiac Surgery Patients
Authors: Blaha Jan , Kopecky Petr , Matias Michal , Hovorka Roman , Kunstyr Jan , Kotulak Tomas , Lips Michal , Rubes David , Stritesky Martin , Lindner Jaroslav , Semrad Michal , Haluzik Martin
Published: February 2009

OBJECTIVE

We performed a randomized trial to compare three insulin-titration protocols for tight glycemic control (TGC) in a surgical intensive care unit: an absolute glucose (Matias) protocol, a relative glucose change (Bath) protocol, and an enhanced model predictive control (eMPC) algorithm.

RESEARCH DESIGN AND METHODS

A total of 120 consecutive patients after cardiac surgery were randomly assigned to the three protocols with a target glycemia range from 4.4 to 6.1 mmol/l. Intravenous insulin was administered continuously or in combination with insulin boluses (Matias protocol). Blood glucose was measured in 1- to 4-h intervals as requested by the protocols.

RESULTS

The eMPC algorithm gave the best performance as assessed by time to target (8.8 ± 2.2 vs. 10.9 ± 1.0 vs. 12.3 ± 1.9 h; eMPC vs. Matias vs. Bath, respectively; P < 0.05), average blood glucose after reaching the target (5.2 ± 0.1 vs. 6.2 ± 0.1 vs. 5.8 ± 0.1 mmol/l; P < 0.01), time in target (62.8 ± 4.4 vs. 48.4 ± 3.28 vs. 55.5 ± 3.2%; P < 0.05), time in hyperglycemia >8.3 mmol/l (1.3 ± 1.2 vs. 12.8 ± 2.2 vs. 6.5 ± 2.0%; P < 0.05), and sampling interval (2.3 ± 0.1 vs. 2.1 ± 0.1 vs. 1.8 ± 0.1 h; P < 0.05). However, time in hypoglycemia risk range (2.9–4.3 mmol/l) in the eMPC group was the longest (22.2 ± 1.9 vs. 10.9 ± 1.5 vs. 13.1 ± 1.6; P < 0.05). No severe hypoglycemic episode (<2.3 mmol/l) occurred in the eMPC group compared with one in the Matias group and two in the Bath group.

CONCLUSIONS

The eMPC algorithm provided the best TGC without increasing the risk of severe hypoglycemia while requiring the fewest glucose measurements. Overall, all protocols were safe and effective in the maintenance of TGC in cardiac surgery patients.
Phosphodiesterase 5 Inhibition Improves β-Cell Function in Metabolic Syndrome
Authors: Hill Kevin D. , Eckhauser Aaron W. , Marney Annis , Brown Nancy J.
Published: February 2009

OBJECTIVE

This study tested the hypothesis that phosphodiesterase 5 inhibition alone or in combination with ACE inhibition improves glucose homeostasis and fibrinolysis in individuals with metabolic syndrome.

RESEARCH DESIGN AND METHODS

Insulin sensitivity, β-cell function, and fibrinolytic parameters were measured in 18 adults with metabolic syndrome on 4 separate days after a randomized, crossover, double-blind, 3-week treatment with placebo, ramipril (10 mg/day), tadalafil (10 mg o.d.), and ramipril plus tadalafil.

RESULTS

Ramipril decreased systolic and diastolic blood pressure, ACE activity, and angiotensin II and increased plasma renin activity. Ramipril did not affect insulin sensitivity or β-cell function. In contrast, tadalafil improved β-cell function (P = 0.01). This effect was observed in women (331.9 ± 209.3 vs. 154.4 ± 48.0 32 μ · mmol−1 · l−1, respectively, for tadalafil treatment vs. placebo; P = 0.01) but not in men. There was no effect of any treatment on fibrinolysis.

CONCLUSIONS

Phosphodiesterase 5 inhibition may represent a novel strategy for improving β-cell function in metabolic syndrome.
Structural and Functional Cardiac Abnormalities in Adolescent Girls with Poorly Controlled Type 2 Diabetes
Authors: Whalley Gillian A. , Gusso Silmara , Hofman Paul , Cutfield Wayne , Poppe Katrina K. , Doughty Robert N. , Baldi J. Chris
Published: February 2009

OBJECTIVE

Type 2 diabetes is associated with left ventricular hypertrophy (LVH) and diastolic dysfunction, which may eventually lead to clinical heart failure. We sought to determine the cardiovascular effects of adolescent-onset type 2 diabetes.

RESEARCH DESIGN AND METHODS

We recruited diabetic girls (8 with type 2 and 11 with type 1 diabetes) from a hospital diabetes service and nondiabetic control subjects (9 lean and 11 overweight) from the schools of the diabetic subjects. Echocardiography and measurements were performed by a single observer, blinded to subject group allocation, and included M-mode left ventricular dimensions, two-dimensional left ventricular mass, Doppler diastolic flows, estimation of left ventricular filling pressure, and systolic longitudinal motion. Left ventricular mass was indexed to height and fat-free body mass. ANOVA was used to compare the groups.

RESULTS

The groups were similar in age and height, but significant differences in body composition were observed. Subjects with type 2 diabetes had larger left ventricular dimensions and left ventricular mass, which persisted when indexed to height. Diastolic filling was impaired in both diabetic groups, and systolic longitudinal function was lower in the type 2 diabetic group. Half of the group with type 2 diabetes met the published criteria for LVH and left ventricular dilatation; 25% had evidence of elevated left ventricular filling pressure in association with structural abnormalities.

CONCLUSIONS

This study has demonstrated preclinical abnormalities of cardiac structure and function in adolescent girls with type 2 diabetes, despite the short duration of diabetes and highlights the potential high cardiovascular risk occurring in adolescent type 2 diabetes.
Insulin Response in Relation to Insulin Sensitivity
Authors: Goedecke Julia H. , Dave Joel A. , Faulenbach Mirjam V. , Utzschneider Kristina M. , Lambert Estelle V. , West Sacha , Collins Malcolm , Olsson Tommy , Walker Brian R. , Seckl Jonathan R. , Kahn Steven E. , Levitt Naomi S.
Published: February 2009

OBJECTIVE

The purpose of this study was to characterize differences in the acute insulin response to glucose (AIRg) relative to insulin sensitivity (SI) in black and white premenopausal normoglycemic South African women matched for body fatness.

RESEARCH DESIGN AND METHODS

Cross-sectional analysis including 57 black and white South African women matched for BMI, SI, AIRg, and the disposition index (AIRg × SI) were performed using a frequently sampled intravenous glucose tolerance test with minimal model analysis, and similar measures were analyzed using an oral glucose tolerance test (OGTT). Body composition was assessed by dual-energy X-ray absorptiometry and computed tomography.

RESULTS

S I was significantly lower (4.4 ± 0.8 vs. 9.4 ± 0.8 and 2.9 ± 0.8 vs. 6.0 ± 0. 8 × 10−5 min−1/[pmol/l], P < 0.001) and AIRg was significantly higher (1,028 ± 255 vs. 352 ± 246 and 1,968 ± 229 vs. 469 ± 246 pmol/l, P < 0.001), despite similar body fatness (30.9 ± 1.4 vs. 29.7 ± 1.3 and 46.8 ± 1.2 vs. 44.4 ± 1.3%) in the normal-weight and obese black women compared with their white counterparts, respectively. Disposition index, a marker of β-cell function, was not different between ethnic groups (3,811 ± 538 vs. 2,966 ± 518 and 3,646 ± 485 vs. 2,353 ± 518 × 10−5 min, P = 0.10). Similar results were obtained for the OGTT-derived measures.

CONCLUSIONS

Black South African women are more insulin resistant than their white counterparts but compensate by increasing their insulin response to maintain normal glucose levels, suggesting an appropriate β-cell response for the level of insulin sensitivity.
Study of partitioning and dynamics of metals in contaminated soil using modified four-step BCR sequential extraction procedure
Authors: Frentiu Tiberiu , Ponta Michaela , Levei Erika , Cordos Emil
Published: February 2009

The modified four-step BCR sequential extraction procedure (exchangeable and weak acid available species, reducible, oxidisable and residual fractions) was used to examine the distribution of As, Cd, Cr, Cu, Pb, and Zn with soil depth in an area (Baia Mare — Bozanta, Romania) with both high natural level of elements considered as toxic and historical pollution resulting from nonferrous metallurgy. The BCR approach proved a high metal input of anthropogenic origin down to 40 cm, while at lower depths the naturally elevated metal content must be considered. Results of the partitioning study and XRD analysis of solid matrix showed the greatest potential for chemical remobilisation of Cd, Zn, and Cu in weak acidic medium as well as their affinity for the oxidisable fraction (organic matter/sulphide). The tendency of Cr, Pb, and As to be immobilised as residual or reducible species on Fe-Mn oxides was evident. Although the partitioning of As in chemically inactive forms such as scorodite (FeAsO4 · 2H2O) soluble under reducible conditions and beudantite (PbFe3(AsO4)(SO4)(OH)2)), a residual species soluble in acid media, chemical mobilisation from soil in groundwater was confirmed. Dynamic processes of metal retention in soil under different conditions, namely acidic, reducing or oxidisable, were predicted from the Pearsonșs correlation analysis of element species with soil characteristics and components such as Fe, Mn, organic matter content, pH, and total element content, respectively. At the moment of the study, soil and groundwater in the area were found to be polluted with As, Cd, Cu, Pb and Zn.
Thirty years' experience with Gamma Knife surgery for metastases to the brain
Authors: Karlsson Bengt , Hanssens Patrick , Wolff Robert , Söderman Michael , Lindquist Christer , Beute Guus
Published: February 2009

Object

The aim of this study was to analyze factors influencing survival time and patterns of distant recurrences after Gamma Knife surgery (GKS) for metastases to the brain.

Methods

Information was available for 1855 of 1921 patients who underwent GKS for single or multiple cerebral metastases at 4 different institutions during different time periods between 1975 and 2007. The total number of Gamma Knife treatments administered was 2448, an average of 1.32 treatments per patient. The median survival time was analyzed, related to patient and treatment parameters, and compared with published data following conventional fractionated whole-brain irradiation.

Results

Twenty-five patients survived for longer than 10 years after GKS, and 23 are still alive. Age and primary tumor control were strongly related to survival time. Patients with single metastases had a longer survival than those with multiple metastases, but there was no difference in survival between patients with single and multiple metastases who had controlled primary disease. There were no significant differences in median survival time between patients with 2, 3–4, 5–8, or > 8 metastases. The 5-year survival rate was 6% for the whole patient population, and 9% for patients with controlled primary disease. New hematogenous spread was a more significant problem than micrometastases in patients with longer survival.

Conclusions

Patient age and primary tumor control are more important factors in predicting median survival time than number of metastases to the brain. Long-term survivors are more common than previously assumed.
Intracranial vertebral artery dissection resulting in fatal subarachnoid hemorrhage: clinical and histopathological investigations from a medicolegal perspective
Authors: Ro Ayako , Kageyama Norimasa , Abe Nobuyuki , Takatsu Akihiro , Fukunaga Tatsushige
Published: February 2009

Object

Subarachnoid hemorrhage (SAH) due to a ruptured intracranial vertebral artery (VA) dissection sometimes results in a sudden fatal outcome. The authors analyzed the relationship between clinical features and histopathological characteristics among fatal cases to establish valuable information for clinical diagnostics and prophylaxis.

Methods

This study included 58 medicolegal autopsy cases of ruptured intracranial VA dissection among 553 fatal nontraumatic cases of SAH that occurred between January 2000 and December 2007. Their clinical features were obtained from autopsy records. Histopathological investigations were performed on cross-sections obtained from all 4-mm segments of whole bilateral intracranial VAs and prepared with H & E and elastica van Gieson staining.

Results

The autopsy cases included 47 males and 11 females, showing a marked predilection for males. The mean age was 46.8 ± 7.7 years, with 78% of the patients in their 40s or 50s. Hypertension was the most frequently encountered history; it was found in 36% of cases from clinical history and in 55% of cases based on autopsy findings. Prodromal symptoms related to intracranial VA dissections were detected in 43% of patients. Headache or neck pain lasting hours to weeks was a frequent complaint. Of patients with prodromal symptoms, 44% had consulted doctors; however, in none of these was SAH or intracranial VA dissection diagnosed at a preventable stage.

Autopsy revealed fusiform aneurysms with medial dissecting hematomas. Apart from ruptured intracranial VA dissection, previous intracranial VA dissection was detected in 25 cases (43%); among them, 10 showed previous dissection of the bilateral intracranial VAs. The incidence of prodromal symptoms (60%) among the patients with previous intracranial VA dissection was significantly higher than that (30%) among cases without previous dissection (chi-square test; p = 0.023). Most previous intracranial VA dissections formed a single lumen resembling nonspecific atherosclerotic lesions, with the exception of 3 cases (12%) with a double lumen.

Conclusions

Intracranial VA dissection resulting in fatal SAH frequently affects middle-aged men with untreated hypertension. Related to the high frequency of prodromal symptoms, latent previous intracranial VA dissection was histopathologically detected. Furthermore, intracranial VA dissection tends to induce multiple lesions affecting both intracranial VAs recurrently. This suggests the importance of an awareness of sustained whole intracranial VA vulnerability for the prevention of recurrence. The incidence of prodromal symptoms was significantly higher among patients with previous intracranial VA dissections. Thus, earlier diagnosis of intracranial VA dissections at the unruptured stage is desirable for prophylaxis against fatal SAH.
Intraoperative monitoring of visual evoked potential: introduction of a clinically useful method
Authors: Sasaki Tatsuya , Itakura Takeshi , Suzuki Kyouichi , Kasuya Hiromichi , Munakata Ryoji , Muramatsu Hiroyuki , Ichikawa Tsuyoshi , Sato Taku , Endo Yuji , Sakuma Jun , Matsumoto Masato
Published: February 2009

Object

To obtain a clinically useful method of intraoperative monitoring of visual evoked potentials (VEPs), the authors developed a new light-stimulating device and introduced electroretinography (ERG) to ascertain retinal light stimulation after induction of venous anesthesia.

Methods

The new stimulating device consists of 16 red light–emitting diodes embedded in a soft silicone disc to avoid deviation of the light axis after frontal scalp-flap reflection. After induction of venous anesthesia with propofol, the authors performed ERG and VEP recording in 100 patients (200 eyes) who were at intraoperative risk for visual impairment.

Results

Stable ERG and VEP recordings were obtained in 187 eyes. In 12 eyes, stable ERG data were recorded but VEPs could not be obtained, probably because all 12 eyes manifested severe preoperative visual dysfunction. The disappearance of ERG data and VEPs in the 13th eye after frontal scalp-flap reflection suggested technical failure attributable to deviation of the light axis. The criterion for amplitude changes was defined as a 50% increase or decrease in amplitude compared with the control level. In 1 of 187 eyes the authors observed an increase in intraoperative amplitude and postoperative visual function improvement. Of 169 eyes without amplitude changes, 17 manifested improved visual function postoperatively, 150 showed no change, and 2 worsened (1 patient with a temporal tumor developed a slight visual field defect in both eyes). Of 3 eyes with intraoperative VEP deterioration and subsequent recovery upon changing the operative maneuver, 1 improved and 2 exhibited no change. The VEP amplitude decreased without subsequent recovery to 50% of the control level in 14 eyes, and all of these developed various degrees of postoperative deterioration of visual function.

Conclusions

With the strategy introduced here it is possible to record intraoperative VEPs in almost all patients except in those with severe visual dysfunction. In some patients, postoperative visual deterioration can be avoided or minimized by intraoperative VEP recording. All patients without an intraoperative decrease in the VEP amplitude were without severe postoperative deterioration in visual function, suggesting that intraoperative VEP monitoring may contribute to prevent postoperative visual dysfunction.
The role of surgery for high-grade intracranial dural arteriovenous fistulas: importance of obliteration of venous outflow
Authors: Liu James K. , Dogan Aclan , Ellegala Dilantha B. , Carlson Jonathan , Nesbit Gary M. , Barnwell Stanley L. , Delashaw Johnny B.
Published: February 2009

Object

Surgical intervention may be required if endovascular embolization is insufficient to completely obliterate intracranial dural arteriovenous fistulas (DAVFs). The authors report their 14-year experience with 23 patients harboring diverse intracranial DAVFs that required surgical intervention.

Methods

Between 1993 and 2007, 23 patients underwent surgery for intracranial DAVFs. The following types of DAVFs were treated: superior petrosal sinus (in 10 patients); parietooccipital (in 3); confluence of sinuses and ethmoidal (in 2 each); and tentorial, falcine, occipital, transverse-sigmoid, superior sagittal, and cavernous sinuses (in 1 patient each). In all cases, the authors' goal was to obliterate the DAVF venous outflow by direct surgical interruption of the leptomeningeal venous drainage. Transarterial embolization was used primarily as an adjunct to decrease flow to the DAVF prior to definitive treatment.

Results

Complete angiographic obliteration of the DAVF was achieved in all cases. There were no complications of venous hypertension, venous infarction, or perioperative death. There were no recurrences and no further clinical events (new hemorrhages or focal neurological deficits) after a mean follow-up of 45 months.

Conclusions

The authors' experience emphasizes the importance of occluding venous outflow to obliterate intracranial DAVFs. Those that drain purely through leptomeningeal veins can be safely obliterated by surgically clipping the arterialized draining vein as it exits the dura. Radical excision of the fistula is not necessary.
Environmental and Nutritional Aspect in Male Infertility
Authors: Begum Hamida , Moniruddin ABM , Nahar Khairun
Published: February 2009

Male and female partner of a couple must be standard and fit to have the capacity to procreate. Studies confirm that male sperm counts are declining and environmental factors as pesticides, exogenous estrogen, heavy metals negatively impact spermatogenesis without any obvious anatomical defects. So, a number of nutritional therapies have been shown to improve sperm count and motility as carnitine, arginine, zinc, selenium and vitamin B12. Numerous anitioxidants have prove beneficial in treating male infertility as Vitamin C, Vitamin E, Glutathione and Coenzyme Q10. This article aims to highlight the correction of nutritional imbalances to encourage optimum sperm production and function, when there is idiopathic impaired spermatogenesis. Â  doi:10.3329/jom.v10i1.1997 Â  J Medicine 2009; 10: 16-19 Â Â
Quadriplegia due to Spinal Subdural Abscess
Authors: Rahman Matiur , Mondol Md Badrul Alam , Matin Nazrul Islam , Siddiqui Md Mahmudur Rahman
Published: February 2009

Spinal subdural abscess (SSA) is a very rare cause of quadriplegia. According to the site of involvement, they may present with paraplegia or rarely quadriplegia. The most common site is thoraco-lumber region, but our patient presented with cervical SSA. We should consider it as a medical emergency because early diagnosis and prompt treatment can save the life and prevent residual disability of the patient. Â  doi:10.3329/jom.v10i1.1998 Â  J Medicine 2009; 10: 20-21
Giganto-acromegaly with Hypogonadotrophic Hypogonadism
Authors: Hoque Mirza Azizul , Azam Md Bakhtiar , Khan Md Golam Kibria , Hoque Md Azharul , Mohammad Quazi Deen
Published: February 2009

Gigantism came from Greek word âGiant'. Pathologically, this condition results from the actions of excessive growth hormone (GH) secretion from the pituitary gland during childhood and adolescent before the closure of epiphyseal growth plates. When the height of an individual is several standard deviations above the mean value for the same age, sex, and ethnicity, the condition is known as gigantism. Pituitary gigantism is extremely rare. If hypersecretion of growth hormone occurs after closure of epiphyseal growth plates the resulting condition is acromegaly. Most patients with gigantism also have features of acromegaly. Â  doi:10.3329/jom.v10i1.1999 J Medicine 2009; 10: 22-24
Incontinentia Pigmenti Involving Only the Skin
Authors: Wahiduzzaman Md
Published: February 2009

Incontinentia pigmenti (IP) is an uncommon disorder which can affect the skin and other systems. . It is an X-linked dominant genodermatosis mainly affecting the female baby with prenatal lethality in boys. It was first reported by Garrod in 1906 and further defined by Bloch and Sulzberger in 1926 and 1928. It can involve the skin only or in addition can affect the central nervous system, eyes and the teeth. The boys do not survive unless associated with Klinefelter syndrome (47, XXY). Morbidity and mortality are related to neurologic and ophthalmologic sequelae. Our presented case did not have any systemic involvement but only cutaneous symptoms. doi:10.3329/jom.v10i1.2000 J Medicine 2009; 10: 25-27
Non-communicable Diseases: Bangladesh Perspective
Authors: Uddin AKM Rafique
Published: February 2009

doi:10.3329/jom.v10i3.2006J Medicine 2009; 10 (Supplement 1): 1-2
Achievement of Awareness in a Diabetic Population
Authors: Hoque Mirza Azizul , Islam Md Sirajul , Khan Md Abdul Maleque , Aziz Rehana , Ahasan HAM Nazmul
Published: February 2009

This cross-sectional survey was carried out during the period, October 2005 to December 2005, among 184 randomly chosen diabetic patients in Khulna Diabetic Centre, Khulna, Bangladesh, to evaluate the knowledge of the patients for their control of diabetes mellitus and also to explore the association(s) of their attitude and knowledge regarding diabetic awareness towards educational status and socio-demographic profile. In this study, we found a significant difference, in diabetic awareness to keep correct blood glucose level, in different educational group. But, it did not influence the subjects of different educational group to visit the diabetic clinic. There was no significant difference in the knowledge of correct blood glucose level and in regularity of visit to the diabetic clinic, in rural and urban people. Knowledge of correct blood glucose level varied significantly among male and female patients, although, no significant variation was found among them in visiting to the diabetic clinic. We can conclude that, diabetic education programs can improve self-regulatory behavior and in the long run, can reduce morbidity and mortality. Â  doi:10.3329/jom.v10i3.2008 J Medicine 2009; 10 (Supplement 1): 7-10 Â
The Glasgow Coma Scale following Acute Stroke and In-hospital Outcome: An Observational Study
Authors: Miah Md Titu , Hoque AKM Aminul , Khan Raihan Rotap , Nur Zannatun , Mahbub Md Shahriar , Rony Rabiul Islam , Tarafder Binoy Krishna , Siddique Md Abu Naser
Published: February 2009

Acute stroke is a heterogeneous condition and the risk of death can be gauged by various factors. This study sought to evaluate GCS score on admission as a prognostic tool of outcome among stroke patients, by observing the GCS score following acute stroke and in-hospital outcome at a tertiary level hospital in Bangladesh. Stroke is a major health problem in developed countries as well as developing countries like Bangladesh. This observational study was conducted among 122 consecutive patients, fulfilling the WHO stroke defining criteria, from 1st January 2007 to 30th June 2007. Mean age was 59.28 Â± 14.89(SD) years and male female ratio was 2.39: 1. Cerebral infarct was 49.13%. Intracerebral hemorrhage and subarachnoid hemorrhage was 31.89% and 18.96% respectively. Overall in-hospital mortality was 15.57% though mortality in patients with cerebral infarcts was nil. Patients presenting with GCS between 3 and 8 caused 12.07% fatality, whereas, none died with GCS score 13-15.Here GCS score showed an inverse relationship with outcome that varied with type of stroke. We can conclude that GCS score on admission might be incorporated as an valuable prognostic parameter in stroke outcome measurement scale. Â  doi:10.3329/jom.v10i3.2009 Â  J Medicine 2009; 10 (Supplement 1): 11-14
Pilot Survey on Cases of Poisoning and its Outcome in Different Category of Hospitals in Bangladesh
Authors: Amin M Robed , Awwal Anisul , Sattar M Abdus , Hasan Rafiqul , Islam Rabiul , Jalil MA , Khandaker Md Abul Kashem , Faiz MA
Published: February 2009

Poisoning and snakebite are commonly encountered emergency situation in Bangladesh. Morbidity per annum reported from static primary health care set up and district hospitals following poisoning are ~ 0.56% of total morbidity. Reports published from the DGHS in 2001 recorded poisoning as fifteenth cause of morbidity & second commonest cause of death second to acute respiratory tract infection (1956). Common poisoning encountered in the community include pesticide poisoning, kerosene poisoning, poisoning by unknown sedative substances for stupefying purpose and with occasional reports of methanol poisoning, aluminium phosphide poisoning, copper sulphate poisoning and puffer fish poisoning. A change in the trends of poisoning particularly âtravel related' poisoning by sedatives instead of previously used âDhatura' have been found in the country. Â  doi:10.3329/jom.v10i3.2010 J Medicine 2009; 10 (Supplement 1): 15-17
Pubic Lice (Pthirus pubis): History, Biology and Treatment vs. Knowledge and Beliefs of US College Students
Authors: Anderson Alice L. , Chaney Elizabeth
Published: February 2009

Pubic lice (Pthirus pubis) maintain a worldwide parasitic population infesting two to over 10 percent of human populations, continuing a presence that has been constant since early evidence 10,000 years ago. Outbreaks in the 1970s have been recorded, but incomplete records preclude description of a definitive population cycle. Current levels of infestation in a US college student population were investigated in this study. Knowledge and opinions of students were also recorded in an online survey administered to college students taking a basic health course at a mid-sized East Coast University. In a group of 817 students, 35 reported experience with pubic lice or other STD infection. Knowledge, beliefs, and treatment attitudes were examined for the 782 students who did not have experience with either pubic lice or STD infection. These students deemed antibiotics as a viable treatment for pubic lice infestation. They also indicated negative attitudes toward the use of pesticide crèmes, which are the most useful prescription. Symptoms and transmission myths in student answers are described.
Enhanced TDMA Based Anti-Collision Algorithm with a Dynamic Frame Size Adjustment Strategy for Mobile RFID Readers
Authors: Shin Kwang Cheol , Park Seung Bo , Jo Geun Sik
Published: February 2009

In the fields of production, manufacturing and supply chain management, Radio Frequency Identification (RFID) is regarded as one of the most important technologies. Nowadays, Mobile RFID, which is often installed in carts or forklift trucks, is increasingly being applied to the search for and checkout of items in warehouses, supermarkets, libraries and other industrial fields. In using Mobile RFID, since the readers are continuously moving, they can interfere with each other when they attempt to read the tags. In this study, we suggest a Time Division Multiple Access (TDMA) based anti-collision algorithm for Mobile RFID readers. Our algorithm automatically adjusts the frame size of each reader without using manual parameters by adopting the dynamic frame size adjustment strategy when collisions occur at a reader. Through experiments on a simulated environment for Mobile RFID readers, we show that the proposed method improves the number of successful transmissions by about 228% on average, compared with Colorwave, a representative TDMA based anti-collision algorithm.