bluuebunny/crossref_metadata_2025 huggingface dataset:
GREEN CHEMISTRY AND ENGINEERING: Drivers, Metrics, and Reduction to Practice
Authors: Marteel Anne E. , Davies Julian A. , Olson Walter W. , Abraham Martin A.
Published: December 2004

▪ Abstract  Green chemistry and engineering is the design of chemical manufacturing systems to minimize their adverse affects on the environment. Thus, a primary goal of green chemistry and engineering is to reduce the environmental impact of chemical processes and chemical manufacturing while simultaneously enhancing the overall process performance. Although it is beneficial to simply reduce the use of organic solvents in chemical processes, green chemistry and engineering goes further, in that it evaluates the entire manufacturing operation to identify techniques that can be applied to minimize the overall process hazard, while maintaining economic practicality. Evaluation of the environmental impacts of the manufacturing process requires a systems approach and appropriate metrics that permit quantitative assessment of environmental hazards. Thus, this chapter begins with a discussion of the drivers for green engineering and the metrics through which processes can be evaluated. Then, the hydroformylation process is used as a case study to illustrate the way in which green chemistry principles can be applied to real processes. Two elements are specifically highlighted: (a) the use of catalysts to facilitate active and selective chemistry and the immobilization of said catalysts within the reactor system, and (b) the development of processes based on benign reaction solvents, and the benefits that can accrue from simplified separations operations.
Evaluating Uncertainties in Regional Photochemical Air Quality Modeling
Authors: Fine James , Vuilleumier Laurent , Reynolds Steve , Roth Philip , Brown Nancy
Published: December 2004

This review evaluates analyses that are or may be performed to estimate uncertainties associated with air quality modeling used in regulatory planning to meet National Ambient Air Quality Standards for ozone. The sources of uncertainties in photochemical air quality simulation models (PAQSMs) are described. Regulatory requirements for evaluating PAQSM performance and uncertainty concerns not addressed through standard performance evaluations are discussed. Available techniques for evaluating uncertainties are presented. Experiences with analyses conducted most commonly are reviewed, as are those that might be used in a cohesive model uncertainty evaluation. The review concludes with a call for renewed emphasis on applying current techniques complemented by heretofore sparsely used diagnostic, corroborative, and alternative approaches and enhanced observational databases.
Meeting Cereal Demand While Protecting Natural Resources and Improving Environmental Quality
Authors: Cassman Kenneth G. , Dobermann Achim , Walters Daniel T. , Yang Haishun
Published: December 2004

Agriculture is a resource-intensive enterprise. The manner in which food production systems utilize resources has a large influence on environmental quality. To evaluate prospects for conserving natural resources while meeting increased demand for cereals, we interpret recent trends and future trajectories in crop yields, land and nitrogen fertilizer use, carbon sequestration, and greenhouse gas emissions to identify key issues and challenges. Based on this assessment, we conclude that avoiding expansion of cultivation into natural ecosystems, increased nitrogen use efficiency, and improved soil quality are pivotal components of a sustainable agriculture that meets human needs and protects natural resources. To achieve this outcome will depend on raising the yield potential and closing existing yield gaps of the major cereal crops to avoid yield stagnation in some of the world's most productive systems. Recent trends suggest, however, that increasing crop yield potential is a formidable scientific challenge that has proven to be an elusive goal.
Dynamics of Land-Use and Land-Cover Change in Tropical Regions
Authors: Lambin Eric F. , Geist Helmut J. , Lepers Erika
Published: December 2004

We highlight the complexity of land-use/cover change and propose a framework for a more general understanding of the issue, with emphasis on tropical regions. The review summarizes recent estimates on changes in cropland, agricultural intensification, tropical deforestation, pasture expansion, and urbanization and identifies the still unmeasured land-cover changes. Climate-driven land-cover modifications interact with land-use changes. Land-use change is driven by synergetic factor combinations of resource scarcity leading to an increase in the pressure of production on resources, changing opportunities created by markets, outside policy intervention, loss of adaptive capacity, and changes in social organization and attitudes. The changes in ecosystem goods and services that result from land-use change feed back on the drivers of land-use change. A restricted set of dominant pathways of land-use change is identified. Land-use change can be understood using the concepts of complex adaptive systems and transitions. Integrated, place-based research on land-use/land-cover change requires a combination of the agent-based systems and narrative perspectives of understanding. We argue in this paper that a systematic analysis of local-scale land-use change studies, conducted over a range of timescales, helps to uncover general principles that provide an explanation and prediction of new land-use changes.
GEOGRAPHICINFORMATIONSCIENCE ANDSYSTEMS FORENVIRONMENTALMANAGEMENT
Authors: Goodchild Michael F.
Published: December 2004

▪ Abstract  The geographic context is essential both for environmental research and for policy-oriented environmental management. Geographic information systems are as a result increasingly important computing applications in this domain, and an understanding of the underlying principles of geographic information science is increasingly essential to sound scientific practice. The review begins by defining terms. Four major sections follow that discuss advances in GIS analysis and modeling, in the supply of geographic data for GIS, in software design, and in GIS representation. GIS-based modeling is constrained in part by architecture, but a number of recent products show promise, and GIS continues to support modeling through the coupling of software. The GIS data supply has benefited from a range of new satellite-based sensors and from developments in ground-based sensor networks. GIS software design is being revolutionized by two developments in the information technology mainstream: the trend to component-based software and object-oriented data modeling. Advances in GIS representation focus largely on time, the third spatial dimension, and uncertainty. References are provided to the more important and recent literature. The concluding section identifies three significant and current trends: toward increasing interoperability of data and services, increasing mobility of information technology, and increasing capabilities for dynamic simulation.
Global State of Biodiversity and Loss
Authors: Dirzo Rodolfo , Raven Peter H.
Published: December 2004

Biodiversity, a central component of Earth's life support systems, is directly relevant to human societies. We examine the dimensions and nature of the Earth's terrestrial biodiversity and review the scientific facts concerning the rate of loss of biodiversity and the drivers of this loss. The estimate for the total number of species of eukaryotic organisms possible lies in the 5–15 million range, with a best guess of ∼7 million. Species diversity is unevenly distributed; the highest concentrations are in tropical ecosystems. Endemisms are concentrated in a few hotspots, which are in turn seriously threatened by habitat destruction—the most prominent driver of biodiversity loss. For the past 300 years, recorded extinctions for a few groups of organisms reveal rates of extinction at least several hundred times the rate expected on the basis of the geological record. The loss of biodiversity is the only truly irreversible global environmental change the Earth faces today.
Urban Centers: An Assessment of Sustainability
Authors: McGranahan Gordon , Satterthwaite David
Published: December 2004

As increasing proportions of the world's population, production, and consumption become concentrated in urban areas, the need for urban development patterns that are more ecologically sustainable becomes obvious. A large proportion of the world's urban population also has needs that are unmet. We review the scale and nature of urban change worldwide, the environmental impacts of these changes, and the potentials and the difficulties in better meeting sustainable development goals in urban centers. The discussion of the interaction between city-based production and consumption and the resources and sinks on which these rely that are outside city boundaries is a reminder that the goal is not sustainable cities but cities that contribute to sustainable development within their boundaries, in the region around them, and globally.
CHARACTERIZING ANDMEASURINGSUSTAINABLEDEVELOPMENT
Authors: Parris Thomas M. , Kates Robert W.
Published: December 2004

▪ Abstract  Sustainable development has broad appeal and little specificity, but some combination of development and environment as well as equity is found in many attempts to describe it. However, proponents of sustainable development differ in their emphases on what is to be sustained, what is to be developed, how to link environment and development, and for how long a time. Despite the persistent definitional ambiguities associated with sustainable development, much work (over 500 efforts) has been devoted to developing quantitative indicators of sustainable development. The emphasis on sustainability indicators has multiple motivations that include decision making and management, advocacy, participation and consensus building, and research and analysis. We select a dozen prominent examples and use this review to highlight their similarities and differences in definition of sustainable development, motivation, process, and technical methods. We conclude that there are no indicator sets that are universally accepted, backed by compelling theory, rigorous data collection and analysis, and influential in policy. This is due to the ambiguity of sustainable development, the plurality of purpose in characterizing and measuring sustainable development, and the confusion of terminology, data, and methods of measurement. A major step in reducing such confusion would be the acceptance of distinctions in terminology, data, and methods. Toward this end, we propose an analytical framework that clearly distinguishes among goals, indicators, targets, trends, driving forces, and policy responses. We also highlight the need for continued research on scale, aggregation, critical limits, and thresholds.
TRACKING MULTIPLE PATHWAYS OF HUMAN EXPOSURE TO PERSISTENT MULTIMEDIA POLLUTANTS: Regional, Continental, and Global-Scale Models
Authors: McKone Thomas E. , MacLeod Matthew
Published: December 2004

▪ Abstract  Widespread observations of organic pollutant compounds in vegetation, soil, animals, and human tissue have motivated research on more accurate characterizations of chemical transport over regional, continental, and global scales. Efforts to assess human and ecosystem exposure to contaminants from multiple environmental media have been evolving over the last several decades. In this review, we summarize the development and evolution of the multimedia mass-balance approach to pollutant fate and exposure evaluation and illustrate some of the calculations used in multimedia assessments. The concepts that form the foundation of Mackay-type mass-balance compartment models are described, and the ongoing efforts to use multimedia models to quantify human exposures are discussed. A series of case studies of varying complexity are used to illustrate capabilities and limitations of selected multimedia approaches. We look to the future and consider current challenges and opportunities in the field of multimedia contaminant fate and exposure modeling.
TESTS OF THEGRAVITATIONALINVERSE-SQUARELAW
Authors: Adelberger E.G. , Heckel B.R. , Nelson A.E.
Published: December 2004

▪ Abstract  We review recent experimental tests of the gravitational inverse-square law and the wide variety of theoretical considerations that suggest the law may break down in experimentally accessible regions.
TOP-QUARK PHYSICS
Authors: Chakraborty Dhiman , Konigsberg Jacobo , Rainwater David
Published: December 2004

▪ Abstract  We survey top-quark physics from what has been learned so far at the Tevatron to the searches planned at present and future colliders. We summarize the richness of the measurements and discuss their possible impact on our understanding of the standard model by pointing out their key elements and limitations. We discuss how the top quark may provide a connection to new or unexpected physics. The literature on many of the topics we address is sizeable. We attempt to consolidate the most salient points into a complete, coherent overview.
DECLINING RATES OF PHYSICAL ACTIVITY IN THE UNITED STATES: What Are the Contributors?
Authors: Brownson Ross C. , Boehmer Tegan K. , Luke Douglas A.
Published: December 2004

▪ Abstract  This review describes current patterns and long-term trends (up to 50 years when possible) related to (a) physical activity, (b) employment and occupation, (c) travel behavior, (d) land use, and (e) related behaviors (e.g., television watching). On the basis of available data, the following trends were observed according to type of physical activity: relatively stable or slightly increasing levels of leisure-time physical activity, declining work-related activity, declining transportation activity, declining activity in the home, and increasing sedentary activity. These result in an overall trend of declining total physical activity. Large differences were noted in the rates of walking for transportation across metropolitan statistical areas. A strong linear increase existed in vehicle miles traveled per person over the past half century, coupled with a strong and consistent trend toward Americans living in suburbs. Although it is difficult to precisely quantify owing to the lack of long-term data, it is apparent that a combination of changes to the built environment and increases in the proportion of the population engaging in sedentary activities put the majority of the American population at high risk of physical inactivity.
THE PUBLIC HEALTH IMPACT OF PRION DISEASES
Authors: Belay Ermias D. , Schonberger Lawrence B.
Published: December 2004

▪ Abstract  Several prion disease–related human health risks from an exogenous source can be identified in the United States, including the iatrogenic transmission of Creutzfeldt-Jakob disease (CJD), the possible occurrence of variant CJD (vCJD), and potential zoonotic transmission of chronic wasting disease (CWD). Although cross-species transmission of prion diseases seems to be limited by an apparent “species barrier,” the occurrence of bovine spongiform encephalopathy (BSE) and its transmission to humans indicate that animal prion diseases can pose a significant public health risk. Recent reports of secondary person-to-person spread of vCJD via blood products and detection of vCJD transmission in a patient heterozygous at codon 129 further illustrate the potential public health impacts of BSE.
Hydroxycitric acid delays intestinal glucose absorption in rats
Authors: Wielinga Peter Y. , Wachters-Hagedoorn Renate E. , Bouter Brenda , van Dijk Theo H. , Stellaard Frans , Nieuwenhuizen Arie G. , Verkade Henkjan J. , Scheurink Anton J. W.
Published: December 2004

In this study, we investigated in rats if hydroxycitric acid (HCA) reduces the postprandial glucose response by affecting gastric emptying or intestinal glucose absorption. We compared the effect of regulator HCA (310 mg/kg) and vehicle (control) on the glucose response after an intragastric or intraduodenal glucose load to investigate the role of altered gastric emptying. Steele's one-compartment model was used to investigate the effect of HCA on systemic glucose appearance after an intraduodenal glucose load, using [U-13C]-labeled glucose and d-[6,6-2H2]-labeled glucose. Because an effect on postabsorptive glucose clearance could not be excluded, the effect of HCA on the appearance of enterally administered glucose in small intestinal tissue, liver, and portal and systemic circulation was determined by [U-14C]glucose infusion. Data show that HCA treatment delays the intestinal absorption of enterally administered glucose at the level of the small intestinal mucosa in rats. HCA strongly attenuated postprandial blood glucose levels after both intragastric ( P < 0.01) and intraduodenal ( P < 0.001) glucose administration, excluding a major effect of HCA on gastric emptying. HCA delayed the systemic appearance of exogenous glucose but did not affect the total fraction of glucose absorbed over the study period of 150 min. HCA treatment decreased concentrations of [U-14C]glucose in small intestinal tissue at 15 min after [U-14C]glucose administration ( P < 0.05), in accordance with the concept that HCA delays the enteral absorption of glucose. These data support a possible role for HCA as food supplement in lowering postprandial glucose profiles.
Heparan sulfate depletion amplifies TNF-α-induced protein leakage in an in vitro model of protein-losing enteropathy
Authors: Bode Lars , Eklund Erik A. , Murch Simon , Freeze Hudson H.
Published: December 2004

Protein-losing enteropathy (PLE), the excessive loss of plasma proteins through the intestine, often correlates with the episodic loss of heparan sulfate (HS) proteoglycans (HSPG) from the basolateral surface of intestinal epithelial cells. PLE onset is often associated with a proinflammatory state. We investigated whether loss of HS or treatment with the proinflammatory cytokine TNF-α directly causes protein leakage and whether a combination of both exacerbates this process. We established the first in vitro model of PLE and measured the flux of albumin/FITC through a monolayer of intestinal HT29 or Caco-2 cells grown on transwells and determined the integrity by transepithelial electrical resistance (TER). Loss of HS from the basolateral surface, either by heparanase digestion or by inhibition of HS synthesis, increased albumin flux 1.58 ± 0.09-fold and reduced TER by 23.4 ± 6.5%. TNF-α treatment increased albumin flux 4.04 ± 0.03-fold and reduced TER by 75.7 ± 4.7% but only slightly decreased HS content. The combined effects of HS loss and TNF-α treatment were not only additive, but synergistic, with a 7.00 ± 0.11-fold increase in albumin flux and a 83.9 ± 8.1% reduction of TER. Coincubation of TNF-α with soluble HS or heparin abolished these synergistic effects. Loss of basolateral HS directly causes protein leakage and amplifies the effects of the proinflammatory cytokine TNF-α. Our findings imply that loss of HSPGs renders patients more susceptible to PLE and offer a potential explanation for the favorable response some PLE patients have to heparin therapy.
TRPC3 mediates pyrimidine receptor-induced depolarization of cerebral arteries
Authors: Reading S. A. , Earley S. , Waldron B. J. , Welsh D. G. , Brayden J. E.
Published: December 2004

We tested the hypothesis that TRPC3, a member of the canonical transient receptor potential (TRP) family of channels, mediates agonist-induced depolarization of arterial smooth muscle cells (SMCs). In support of this hypothesis, we observed that suppression of arterial SMC TRPC3 expression with antisense oligodeoxynucleotides significantly decreased the depolarization and constriction of intact cerebral arteries in response to UTP. In contrast, depolarization and contraction of SMCs induced by increased intravascular pressure, i.e., myogenic responses, were not altered by TRPC3 suppression. Interestingly, UTP-evoked responses were not affected by suppression of a related TRP channel, TRPC6, which was previously found to be involved in myogenic depolarization and vasoconstriction. In patch-clamp experiments, UTP activated a whole cell current that was greatly reduced or absent in TRPC3 antisense-treated SMCs. These results indicate that TRPC3 mediates UTP-induced depolarization of arterial SMCs and that TRPC3 and TRPC6 may be differentially regulated by receptor activation and mechanical stimulation, respectively.
Independent modification of baroreceptor and exercise pressor reflex function by nitric oxide in nucleus tractus solitarius
Authors: Smith Scott A. , Mitchell Jere H. , Li Jianhua
Published: December 2004

It has been suggested that nitric oxide (NO) is a key modulator of both baroreceptor and exercise pressor reflex afferent signals processed within the nucleus tractus solitarius (NTS). However, studies investigating the independent effects of NO within the NTS on the function of each reflex have produced inconsistent results. To address these concerns, the effects of microdialyzing 10 mM l-arginine, an NO precursor, and 20 mM NG-nitro-l-arginine methyl ester (l-NAME), an NO synthase inhibitor, into the NTS on baroreceptor and exercise pressor reflex function were examined in 17 anesthetized cats. Arterial baroreflex regulation of heart rate was quantified using vasoactive drugs to induce acute changes in mean arterial pressure (MAP). To activate the exercise pressor reflex, static hindlimb contractions were induced by electrical stimulation of spinal ventral roots. To isolate the exercise pressor reflex, contractions were repeated after barodenervation. The gain coefficient of the arterial cardiac baroreflex was significantly different from control (−0.24 ± 0.04 beats·min−1·mmHg−1) after the dialysis of l-arginine (−0.18 ± 0.02 beats·min−1·mmHg−1) and l-NAME (−0.29 ± 0.02 beats·min−1·mmHg−1). In barodenervated animals, the peak MAP response to activation of the exercise pressor reflex (change in MAP from baseline, 39 ± 7 mmHg) was significantly attenuated by the dialysis of l-arginine (change in MAP from baseline, 29 ± 6 mmHg). The results demonstrate that NO within the NTS can independently modulate both the arterial cardiac baroreflex and the exercise pressor reflex. Collectively, these findings provide a neuroanatomical and chemical basis for the regulation of baroreflex and exercise pressor reflex function within the central nervous system.
Akinetic myocardial infarcts must contain contracting myocytes: finite-element model study
Authors: Dang Alan B. C. , Guccione Julius M. , Mishell Jacob M. , Zhang Peng , Wallace Arthur W. , Gorman Robert C. , Gorman Joseph H. , Ratcliffe Mark B.
Published: December 2004

Infarcted segments of myocardium demonstrate functional impairment ranging in severity from hypokinesis to dyskinesis. We sought to better define the contributions of passive material properties (stiffness) and active properties (contracting myocytes) to infarct thickening. Using a finite-element (FE) model, we tested the hypothesis that infarcted myocardium must contain contracting myocytes to be akinetic and not dyskinetic. A three-dimensional FE mesh of the left ventricle was developed with echocardiographs from a reperfused ovine anteroapical infarct. The nonlinear stress-strain relationship for the diastolic myocardium was anisotropic with respect to the local muscle fiber direction, and an elastance model for active fiber stress was incorporated. The diastolic stiffness ( C) and systolic material property (isometric tension at longest sarcomere length and peak intracellular calcium concentration, Tmax) of the uninfarcted remote myocardium were assumed to be normal ( C = 0.876 kPa, Tmax = 135.7 kPa). Diastolic and systolic properties of the infarct necessary to produce akinesis, defined as an average radial strain between −0.01 and 0.01, were determined by assigning a range of diastolic stiffnesses and scaling infarct Tmax to represent the percentage of contracting myocytes between 0% and 100%. As C was increased to 11 times normal ( C = 10 kPa) the percentage of Tmax necessary for akinesis increased from 20% to 50%. Without contracting myocytes, C = 250 kPa was necessary to achieve akinesis. If infarct stiffness is <285 times normal, contracting myocytes are required to prevent dyskinetic infarct wall motion.
Adiponectin inhibits LPS-induced NF-κB activation and IL-6 production and increases PPARγ2 expression in adipocytes
Authors: Ajuwon Kolapo M. , Spurlock Michael E.
Published: December 2004

Obesity and insulin resistance are often associated with lower circulating adiponectin concentrations and elevated serum interleukin-6 (IL-6) and/or tumor necrosis factor-α (TNF-α). Adiponectin suppresses activation of nuclear factor-κB (NF-κB) in aortic endothelial cells and porcine macrophages. Accordingly, we hypothesized that adiponectin is an anti-inflammatory hormone and suppresses activation of NF-κB in adipocytes. Because peroxisome proliferator-activated receptor γ2 (PPARγ2) antagonizes the transcriptional activity of NF-κB, we determined whether adiponectin alters PPARγ2 expression in pig adipocytes. In addition, we determined whether interferon-γ alters the expression of PPARγ2 in the presence or absence of adiponectin. Primary adipocytes from pig subcutaneous adipose tissue were treated with or without lipopolysaccharide (LPS; 10 μg/ml) and adiponectin (30 μg/ml), and nuclear extracts were obtained for gel shift assays to assess nuclear localization of NF-κB. Whereas LPS induced an increase in NF-κB activation, adiponectin suppressed both NF-κB activation and the induction of IL-6 expression by LPS ( P < 0.05). Similar results were obtained in 3T3-L1 adipocytes. In addition, adiponectin antagonized LPS-induced increase in TNF-α mRNA expression ( P < 0.05) and tended ( P < 0.065) to diminish its accumulation in the culture media in 3T3-L1 adipocytes. Adiponectin also induced an upregulation of PPARγ2 mRNA ( P < 0.05). Although IFN-γ did not reduce the basal expression of PPARγ2, it suppressed PPARγ2 induction by adiponectin ( P < 0.05). These findings indicate that adiponectin may be a local regulator of inflammation in the adipocyte and adipose tissue via its regulation of the NF-κB and PPARγ2 transcription factors.
Systemic arterial pressure response to two weeks of Tempol therapy in SHR: involvement of NO, the RAS, and oxidative stress
Authors: Yanes Licy , Romero Damian , Iliescu Radu , Cucchiarelli Valeria E. , Fortepiani Lourdes A. , Santacruz Francisco , Bell William , Zhang Huimin , Reckelhoff Jane F.
Published: December 2004

The roles of nitric oxide (NO) and plasma renin activity (PRA) in the depressor response to chronic administration of Tempol in spontaneously hypertensive rats (SHR) are not clear. The present study was done to determine the effect of 2 wk of Tempol treatment on blood pressure [mean arterial pressure (MAP)], oxidative stress, and PRA in the presence or absence of chronic NO synthase inhibition. SHR were divided into four groups: control, Tempol (1 mmol/l) alone, nitro-l-arginine methyl ester (l-NAME, 4.5 mg·kg−1·day−1) alone, and Tempol + l-NAME for 2 wk. With Tempol, MAP decreased by 22%: 191 ± 3 and 162 ± 21 mmHg for control and Tempol, respectively ( P < 0.05). l-NAME increased MAP by 16% (222 ± 2 mmHg, P < 0.01), and l-NAME + Tempol abolished the depressor response to Tempol (215 ± 3 mmHg, P < 0.01). PRA was not affected by Tempol but was increased slightly with l-NAME alone and 4.4-fold with l-NAME + Tempol. Urinary nitrate/nitrite increased with Tempol and decreased with l-NAME and l-NAME + Tempol. Tempol significantly reduced oxidative stress in the presence and absence of l-NAME. In conclusion, in SHR, Tempol administration for 2 wk reduces oxidative stress in the presence or absence of NO, but in the absence of NO, Tempol is unable to reduce MAP. Therefore, NO, but not changes in PRA, plays a major role in the blood pressure-lowering effects of Tempol. These data suggest that, in hypertensive individuals with endothelial damage and chronic NO deficiency, antioxidants may be able to reduce oxidative stress but not blood pressure.
The effect of hypothalamo-pituitary disconnection on the renin-angiotensin system in the late-gestation fetal sheep
Authors: Chen Kai , Carey Luke C. , Liu Jingfang , Valego Nancy K. , Tatter Stephen B. , Rose James C.
Published: December 2004

The activity of the renin-angiotensin system (RAS) increases significantly in the late-gestation fetal sheep. Fetal cortisol is also increased during this time, and it is thought that the increase in cortisol may modulate the RAS changes. Previous studies have examined the effects of cortisol infusion on RAS activity, but the effects of blocking the peripartum increase in cortisol concentrations on the developmental changes in the RAS are not known. Therefore, we utilized the technique of hypothalamic-pituitary disconnection (HPD), which prevents the cortisol surge from occurring, to investigate the importance of the late-gestation increase in cortisol on the ontogenic changes in RAS activity. HPD of fetal sheep was performed at 120 days of gestational age (dGA), and fetuses were delivered between 135 and 139 dGA. Control fetuses were sham operated. HPD blocked the late-gestation cortisol increase but did not alter renal renin mRNA, renal renin or prorenin protein content, nor plasma renin levels compared with sham operated. However, HPD fetuses had increased ANG II receptor subtype 1 (AT1) mRNA and protein expression in the kidney and lungs. ANG II receptor subtype 2 (AT2) expression was not altered in these tissues at either mRNA or protein level. HPD did not change AT1 or AT2 mRNA in the left ventricle but did result in decreased protein levels for both receptors. These studies demonstrate that blockade of the naturally occurring increase in fetal cortisol concentration in late gestation is associated with tissue-specific alterations in expression of AT1 and AT2 receptors. These changes may impact on fetal tissue maturation and hence have consequences in postnatal life.
Interleukin 1β enhances non-rapid eye movement sleep and increases c-Fos protein expression in the median preoptic nucleus of the hypothalamus
Authors: Baker F. C. , Shah S. , Stewart D. , Angara C. , Gong H. , Szymusiak R. , Opp M. R. , McGinty D.
Published: December 2004

Interleukin 1β (IL-1) is a key mediator of the acute phase response in an infected host and acts centrally to coordinate responses to an immune challenge, such as fever and increased non-rapid eye movement (NREM) sleep. The preoptic area (POA) is a primary sleep regulatory center in the brain: the ventrolateral POA (VLPO) and median preoptic nucleus (MnPN) each contain high numbers of c-Fos protein immunoreactive (IR) neurons after sleep but not after waking. We hypothesized that IL-1 mediates increased NREM sleep through activation of these sleep-active sites. Rats injected intracerebroventricularly with IL-1 (10 ng) at dark onset spent significantly more time in NREM sleep 4–5 h after injection. This increase in NREM sleep was associated with increased numbers of Fos-IR neurons in the MnPN, but not in the VLPO. Fos IR in the rostral MnPN was significantly increased 2 h post IL-1 injection, although the percentage of NREM sleep in the preceding 2 h was the same as controls. Fos IR was also increased in the extended VLPO 2 h postinjection. Finally, Fos IR in the MnPN did not differ significantly between IL-1 and vehicle-treated rats that had been sleep deprived for 2 h postinjection, but it was increased in VLPO core. Taken together, these results suggest that Fos IR in the MnPN after IL-1 is not independent of behavioral state and may require some threshold amount of sleep for its expression. Our results support a hypothesis that IL-1 enhances NREM sleep, in part, through activation of neurons in the MnPN of the hypothalamus.
Role of FISH on Uncultured Amniocytes for the Diagnosis of Aneuploidies in the Presence of Fetal Anomalies
Authors: Locatelli Anna , Mariani Silvana , Ciriello Elena , Dalprà Leda , Villa Nicoletta , Sala Elena , Vergani Patrizia
Published: December 2004

Objective: To assess the accuracy of fluorescent in situ hybridization (FISH) on amniocytes in fetuses affected by structural malformations suggestive of chromosomal anomalies. Methods: FISH of uncultured amniotic fluid cells and conventional cytogenetic analysis were performed on 48 pregnancies with ultrasonographic (US) evidence of fetal anomalies. The AneuVysion® assay (Vysis) with specific probes for chromosomes 13, 18, 21, X and Y, was used. Amniotic fluid samples were obtained between the 14th and 34th weeks of gestation. Results: In cases with a single abnormal US finding (n = 15), 5 aneuploidies were detected (1 case of trisomy 13 and 4 of trisomy 21). In the group with two or more malformations (n = 33) there were 15 aneuploidies (9 cases of trisomy 18, 2 of trisomy 21, 2 monosomy X, 1 trisomy 13, and 1 triploidy). In this group, conventional cytogenetic analysis revealed two additional chromosomal anomalies not detectable by FISH (1 trisomy 16 mosaic, and a terminal deletion 4p). No sex aneuploidies were observed. Conclusions: The lack of false-positive diagnosis in the FISH analysis in our sample prompts us to consider interphase FISH as a useful tool in pregnancies at high risk for chromosomal aneuploidies. When FISH analysis is normal, the overall risk of chromosomal abnormalities is significantly reduced. However, the finding of two chromosomal anomalies undetectable by AneuVysion® assay confirms the need for conventional chromosome analysis to complement FISH results. Moreover, the results collected here, in agreement with those already reported in the literature, indicate that FISH analysis on uncultured amniocytes can play an important role in counselling and decision-making, especially in cases at risk for aneuploidies, such as those with structural abnormalities at US.
Massive Subchorionic Hematoma: Peculiar Prenatal Images and Review of the Literature
Authors: Nishijima Koji , Shukunami Ken-ichi , Tsuyoshi Hideaki , Orisaka Makoto , Tajima Kimihisa , Kurokawa Tetsuji , Yoshida Yoshio , Kotsuji Fumikazu
Published: December 2004

Massive subchorionic hematoma is a localized collection of blood or hematoma in the placenta, and can result in serious obstetrical complications. The condition can be diagnosed antenatally by ultrasound. However, no reports have previously described the same condition featuring an intraplacental fluid–fluid level on imaging studies. We report a case of massive subchorionic hematoma diagnosed prenatally, and propose an additional peculiar finding detectable on both the ultrasound and magnetic resonance images: the intraplacental fluid–fluid level. We also review previously reported cases that were detected by ultrasonography.
Severe Variable Decelerations and Fetal Pulse Oximetry during the Second Stage of Labor
Authors: Salamalekis Emanouel , Bakas Panagiotis , Saloum Ioannis , Vitoratos Nikolaos , Creatsas Georgios
Published: December 2004

Objectives: The aim of the study was to investigate the usefulness of fetal pulse oximetry in cases of severe variable decelerations in the second stage of labor. Methods: It is a prospective study including 58 patients. Thirty-eight patients (group A) had a normal uncomplicated labor and 20 patients (group B) developed severe variable decelerations during the second stage of labor. All patients were primiparous with normal pregnancies and had electronic fetal monitoring of labor in conjunction with fetal pulse oximetry. An estimation of fetal pH and base deficit was performed at delivery in all patients. Results: There was no statistically significant difference in relation to maternal age and gestational age between the two groups. Group A patients did not delivered neonates with metabolic acidosis. Six out of 20 (group B) patients delivered neonates with a pH <7.10 despite a fetal pulse oximetry reading of >30%. Conclusions: It appears that fetal pulse oximetry is not capable of detecting pre-acidotic or acidotic fetuses during the second stage of labor in patients with severe variable decelerations and the management of such patients should be supported by fetal scalp pH when indicated or otherwise the obstetrician should expedite delivery either with assisted operative delivery or cesarean section. Fetal heart rate monitoring was introduced into clinical practice over 30 years ago. It continues to be the predominant method of intrapartum fetal surveillance despite worries about its accuracy and efficacy.
Prevention of Graft Rejection by Donor Type II CD8+ T Cells (Tc2 Cells) Is Not Sufficient to Improve Engraftment in Fetal Transplantation
Authors: Chen Jeng-Chang , Chang Ming-Ling , Lee Hanmin , Muench Marcus O.
Published: December 2004

Objectives: Tc2 cells, a subset of CD8+ T cells, are able to facilitate engraftment in a murine model of postnatal allogeneic bone marrow transplantation. The purpose of this study was to evaluate whether Tc2 cells could improve engraftment in fetal transplantation. Methods: Gestational day 13 C57BL/6 (H-2b) fetal mice were used as recipients, adult B6D2F1 mice (C57BL/6 × DBA/2, H-2b/d) as donors, and splenocytes from B6C3F1 (C57BL/6 × C3H/He, H-2b/k) mice were used as stimulators in cultures used to generate the Tc2 cells from B6D2F1 mice. Peripheral blood chimerism was examined monthly for 3 months. Thereafter, recipients were sacrificed to evaluate the levels of peritoneal, splenic and bone marrow chimerism. The T-cell responses of recipient splenocytes to cells of host origin were measured as a proliferative response in mixed lymphocyte cultures. Results: Low levels of peripheral blood cell chimerism (<0.3%) were observed at 1 month of age, which declined further by 3 months of age. The levels of donor cells in the spleen, bone marrow and peritoneal cavity were usually not more than 0.05%. The peritoneal cavity tended to have higher levels of donor cells with 1 recipient sustaining as high as 25.03% at the age of 3 months. Higher peritoneal chimerism correlated with a lower donor-specific T-cell response. Conclusions: Transplantation of Tc2 cells was insufficient to improve bone marrow engraftment in utero, suggesting that graft rejection is not the major barrier to successful in utero transplantation. Donor cells can persist in the peritoneal cavity and might play an important role in inducing immune tolerance in fetuses.
Prediction of Preeclampsia or Intrauterine Growth Restriction by Second Trimester Serum Screening and Uterine Doppler Velocimetry
Authors: Audibert François , Benchimol Yehouda , Benattar Clarisse , Champagne Catherine , Frydman René
Published: December 2004

Objective: To assess the performance of screening for preeclampsia and intrauterine growth restriction by combining second trimester maternal serum screening and uterine Doppler ultrasound. Methods: A cohort of 2,615 women underwent both maternal serum screening (using human chorionic gonadotropin (hCG) and α-fetoprotein (AFP)), and second trimester uterine artery Doppler. The sensitivity, specificity and predictive value of different combinations of both tests were compared. Results: The mean values for hCG and AFP were significantly higher in women with subsequent preeclampsia (p < 0.0003 and p < 0.03, respectively). Taking into account obstetrical history, hCG and AFP levels, notching on uterine artery Doppler and parity, the adjusted odds ratios were significantly higher for a high level of hCG for preeclampsia, intrauterine growth restriction (IUGR) and pregnancy-induced hypertension. AFP level >1.5 MoM (multiples of the median) was significantly correlated with subsequent IUGR. The presence of a uterine notch was associated with a significantly higher risk of both preeclampsia and IUGR. The combination of an elevated serum level and the presence of a uterine notch had a positive predictive value (PPV) for preeclampsia of 25 and 21% for hCG and AFP, respectively. The combination of a bilateral notch with a low level of hCG or a high level of AFP had a PPV for IUGR of 50 and 43%, respectively. The sensitivity of the different tests ranged from 2 to 40%. Conclusion: The combination of serum markers and abnormal uterine Doppler ultrasound improves the identification of women at risk for subsequent pregnancy complications. These results should encourage care providers to perform a uterine Doppler ultrasound when serum markers are abnormal. However, the sensitivity of these tests is too low to provide an efficient generalized screening.
Prenatal Detection of an Interstitial Deletion in 4p15 in a Fetus with an Increased Nuchal Skin Fold Measurement
Authors: South Sarah T. , Corson Virginia L. , McMichael Joseph L. , Blakemore Karin J. , Stetten Gail
Published: December 2004

Objectives: The detection of an increased nuchal translucency (NT) or nuchal fold (NF) measurement is associated with an increased risk of common aneuploidies. Only rarely is it associated with other types of chromosome abnormalities. We report the prenatal finding of an increased NF in a fetus with an interstitial 4p deletion. Methods: Standard karyotype analysis was followed by FISH with research generated BAC probes to precisely map the 4p deletion. Results: The karyotype of the fetus was determined to be 46,XX,del(4)(p15.2p16.1) by G-banding analysis and was refined to 46,XX,del(4) (p15.1p15.32) after FISH analysis. The breakpoints were narrowed to 150 kb regions on each side. The deletion is approximately 14.5 Mb, containing approximately 47 genes. Conclusions: We report a case of an increased NF measurement associated with a 4p deletion. A literature review revealed a previous case of a 4p deletion in a fetus with an increased NT. Since chromosome deletions are rarely associated with an increased NT or NF, we believe it is significant that a 4p deletion has now been found in two unrelated cases. We mapped the deletion with BAC probes, generating a list of possible candidate genes involved in the pathogenesis of increased nuchal skin folds.
Sequelae of Parenteral Drug Abuse Involving the External Genitalia
Authors: Mireku-Boateng A.O. , Nwokeji Cordell
Published: December 2004

Intravenous drug abuse continues to be a major social problem in the USA. Many drug abusers eventually run out of usual intravenous sites and begin to utilize more unusual sites. Some of these sites include the cervical veins and the superficial dorsal vein of the penis. Sometimes the vein is missed and there is extravasation of the drug subcutaneously or intracorporeally. Acute cavernositis, priapism, penile subcutaneous hematoma, penile ulcerations and corporal fibrosis as well as Fournier’s gangrene are some of the sequelae of these adventures. We describe our experience with these situations and review the management of penile ulcers. Material and Methods: Six patients who were seen in our general urology practice in Washington, D.C., with parenteral drug abuse involving the external genitalia were studied. Results: Complications of acute cavernositis, priapism and penile ulcers were observed in this group. Conclusion: It is essential to be aware that these habits occur as well as some of the complications outlined here. We review the management of penile ulcers.
Electrolitholysis – From Basic Research to the Formulation of a New Therapeutic Method
Authors: Fina Ernesto , Cozzolino Santolo , Gonzalez y Rainero Enrico
Published: December 2004

Objective: An electrochemical method, based on anodic oxidation and/or protolysis, has been developed with the aim of extending it to the dissolution of urinary stones. The method has been named electrolitholysis, or ELLYS. An ex vivo experimental trial has been performed to check the current intensity needed to obtain the dissolution of stones without lesions to tissues. A new therapeutic method has been conceived based on these preliminary findings. Materials and Methods: An ex vivo experimental trial has been performed on twelve bladders surgically removed from pigs and placed in an experimental model resembling possible vital organs; the electrolytic dissolution of natural urinary stones was then performed in these bladders. Results: The ex vivo trial showed that the method is safe and reliable if the current intensity is maintained at ≤30 mA. Conclusions: A new therapy based on a new concept has been conceived which can be delivered percutaneously through an electrified spiral stent implanted several days into renal cavities and connected with a power supplier (battery) attached to the patient’s flank.
Relationship between Penile Hemodynamic Parameters Assessed by Color Doppler Ultrasonography and Penile Rigidity Recorded by the RigiScan Plus
Authors: Mizuno Ichiro , Fuse Hideki , Fujiuchi Yasuyoshi , Nagakawa Osamu , Akashi Takuya
Published: December 2004

Objective: We studied the relationship between penile hemodynamic parameters assessed by color Doppler ultrasonography and penile rigidity estimated by objective measurement. Patients and Methods: A total 37 patients with erectile dysfunction were examined. After intracavernous injection of 20 µg prostaglandin E1, we measured their penile hemodynamic parameters in the cavernous arteries by color Doppler ultrasonography. Simultaneously, the RigiScan Plus device was used for real-time evaluation of penile rigidity. Hemodynamic parameters were correlated with penile rigidity. Results: Peak systolic velocity and resistive index were significantly correlated with penile tip (r = 0.54, r = 0.72, respectively) and base (r = 0.55, r = 0.76, respectively) rigidity; there was no significant correlation between end-diastolic velocity and penile rigidity. Conclusions: Peak systolic velocity and resistive index were strongly correlated with penile rigidity in patients with erectile dysfunction during intracavernous pharmacological testing. The resistive index in particular appeared to be the most valid parameter for assessment of penile rigidity.
Suture Materials: Do They Affect Fistula and Stricture Rates in Flap Urethroplasties?
Authors: Cimador M. , Castagnetti M. , Milazzo M. , Sergio M. , de Grazia E.
Published: December 2004

Introduction: The effect of suture materials on urethroplasty complications is debated. Indeed, materials with a delayed absorption might either reduce the incidence of fistulas by ensuring a prolonged approximation of neo-urethral edges or increase the risk of urethral strictures due to a prolonged tissue reaction during suture absorption. We retrospectively evaluated the role of suture materials in the complication rate of urethroplasty procedures performed in our institution over a 10-year period. Patients and Methods: Three hundred and thirty-six boys undergoing a flap procedure (parameatal based, preputial tube, or onlay preputial flap) for hypospadias repair were considered for this study. The patients were stratified into two groups according to the suture material used for urethroplasty. Polyglactin (Vicryl®), a polyfilament with intermediate absorption, was used in 254 group A patients, whereas polydioxanone (PDS®), a monofilament with prolonged absorption, was used in 82 group B patients. The success of a one-stage repair and stricture and fistula rates were evaluated. Results: A successful one-stage repair was achieved in 82% of the group A and in 83% of the group B patients (p = 0.97). No statistically significant differences were noted in fistula and/or stricture rates in the two groups, even considering each procedure separately. Conclusions: This series suggests that suture materials do not affect the complication rate in flap urethroplasty procedures. Appropriate technique, meticulous surgery, and surgeon experience seem to be more crucial factors. A randomized trial is warranted.
Diagnostic Value of Tumour Marker Regression Models in Stage 1 Marker-Positive Testicular Cancer
Authors: May Matthias , Helke Christian , Nitzke Thomas , Seehafer Matthias , Vogler Horst , Hoschke Bernd
Published: December 2004

The decay pattern and half-life period evaluation of serum tumour markers are useful parameters in the management of testicular cancer in clinic stage 1. α-Fetoprotein and human chorionic gonadotropin serum levels measured after orchiectomy can be used to predict the tumour stage. However, the optimal strategy for marker analysis after orchiectomy has not yet been defined. In this article we describe a graphic interactive method which uses tumour marker clearance to help identify patients with occult metastases after orchiectomy.