bluuebunny/crossref_metadata_2025 huggingface dataset:
XRF, XRD, and Thermal Analysis Techniques for Quantitative Determination of Portland Cement and Slag Cement Constituents
Authors: Vidican Ioana , Phan Binh , Farr Jerry , Norton Newell
Published: October 2008

Two rapid test methods to determine and quantify sulfate forms in cement are presented—DSC and XRD. The DSC method is applicable to hydrated calcium sulfates: gypsum and bassanite. Its description includes preparation of standards, calibration curves, and calculation of hydrated sulfates in an unknown cement sample. The XRD method is used qualitatively and quantitatively for both hydrated and nonhydrated sulfate forms. The qualitative approach is used to identify the presence of sulfates in cement samples. The quantitative approach describes the Rietveld analysis applied to a cement sample containing gypsum, bassanite, anhydrite, and arcanite. The calculated total SO3 content is compared with another direct analytical technique (Sulfur Analyzer). The other two methods used to determine the amount of granulated blast furnace slag added to cement are discussed—DTA and XRD. With the DTA method, the exothermic peak that accompanies slag devitrification at high temperatures is measured and converted in slag percentages. The method’s description includes preparation of standards, calibration curve, and calculation of slag content of an unknown cement sample. The XRD method works as a qualitative tool to show the effect of amorphous slag to a cement diffractogram as well as a quantitative tool (Rietveld analysis using an internal standard). Rietveld analysis on cement containing slag samples is used with XRF oxide analysis to correct the Bogue formula calculation for C3S. Three different calculations/corrections are discussed showing reasonably good approximate results.
Ovarian stimulation with FSH reduces phosphorylation of gonadotrope progesterone receptor and LH secretion in the rat
Authors: Gordon Ana , Garrido-Gracia José C , Aguilar Rafaela , Guil-Luna Silvia , Millán Yolanda , de las Mulas Juana Martín , Sánchez-Criado José E
Published: October 2008

Administration of human FSH (hFSH) to cyclic rats during the dioestrous phase attenuates progesterone receptor (PR)-dependent events of the preovulatory LH surge in pro-oestrus. The increased bioactivity of the putative ovarian gonadotropin surge inhibiting/attenuating factor induced by hFSH treatment is not associated with a decrease in PR protein expression, and the possibility of its association at a PR posttranslational effect has been raised. The present experiments aimed to analyse PR phosphorylation status in the gonadotrope of rats with impaired LH secretion induced byin vivohFSH injection. Two experimental approaches were used. First, incubated pro-oestrous pituitaries from hFSH-injected cycling and oestrogen-treated ovariectomized (OVX) rats were used to analyze the effect of calyculin, an inhibitor of intracellular phosphatases, on PR-dependent LH release, which was measured in the incubation medium by RIA. Second, pituitaries taken from hFSH-injected intact cycling and OVX rats and later incubated with P or GNRH1 were used to assess the phosphorylation rate of gonadotrope. The latter was analysed in formalin-fixed, paraffin-embedded tissue sections by immunohistochemistry using a MAB that recognizes the phosphorylated (p) form of PR at Ser294. Calyculin reduced the ovary-mediated inhibition of hFSH in GNRH1-stimulated LH secretion. In addition, the immunohistochemical expression of pSer294 PR was significantly reduced after ovarian stimulation with hFSH in pituitaries from pro-oestrous rats incubated with P or GNRH1. Altogether, these results suggested that the ovarian-dependent inhibitory effect of FSH injection on the preovulatory LH secretion in the rat may involve an increase in dephosphorylation of PR.
Interoceptive Exposure Exercises for Evoking Depersonalization and Derealization: A Pilot Study
Authors: Lickel James , Nelson Elizabeth , Lickel Athena Hayes , Deacon Brett
Published: October 2008

This study examined the potential of 11 interoceptive exposure exercises to produce depersonalization and derealization among high anxiety-sensitive undergraduate students. Inspired by a February 2007 thread on the Association for Behavioral and Cognitive Therapies listserv, we identified nine exercises and compared their capacity to produce depersonalization and derealization with two previously validated tasks: mirror and dot staring. Results indicated that five exercises, including hyperventilation (1 minute), hyperventilation (5 minutes), hyperventilation plus spiral staring, hyperventilation plus strobe light, and strobe light alone, were superior to either mirror or dot staring at inducing depersonalization or derealization. If replicated in a clinical sample, our findings may be used to assist clinicians seeking to evoke these states via interoceptive exposure.
Interoceptive Exposure as a Prelude to Trauma-Related Exposure Therapy in a Case of Posttraumatic Stress Disorder With Substantial Comorbidity
Authors: Wald Jaye
Published: October 2008

This article illustrates the use of interoceptive exposure therapy (IE) combined with trauma-related exposure therapy (TRE) for a patient with chronic posttraumatic stress disorder (PTSD) with comorbid major depressive disorder, panic attacks, and chronic pain. The patient completed four sessions of IE followed by eight sessions of TRE. During IE sessions, there was a reduction of peak anxiety and catastrophic beliefs during the exercises she practiced. On completing IE, there was a statistically significant decrease in anxiety sensitivity and depression. Following TRE, there were statistically significant improvements in PTSD symptoms but significant worsening of depression. Although not statistically significant, there was some lessening of her general anxiety and pain during treatment. The combined treatment effect of IE + TRE appeared to produce more potent results than either IE or TRE alone. The potential benefits and limitations of the use of IE as a prelude to TRE in complex cases of PTSD are discussed.
Chromium occurrence and speciation in Baltimore Harbor sediments and porewater, Baltimore, Maryland, USA
Authors: Graham Andrew M. , Wadhawan Amar R. , Bouwer Edward J.
Published: October 2008

Industrial activities in the Baltimore Harbor, Baltimore, Maryland, USA, have resulted in widespread chromium contamination of sediments. A comprehensive analysis of Cr speciation in sediment and porewater collected from 22 locations in the Baltimore Harbor was completed to understand Cr bioavailability and probability of toxicity due to Cr in sediments. The analysis employed a reverse-phase ion-pair high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) method. Sub-microgram-per-liter determination of Cr(III) and Cr(VI) in environmental samples was found, with method validation revealing broad method applicability of HPLC-ICP-MS to a wide range of sample types. The major limitation of the method was poor Cr species separation in high ionic strength solutions (greater than 0.1 M NaCl). Total Cr concentrations in Baltimore Harbor sediments ranged from 2.5 to 1,050 mg/kg with 11 of the 22 sites containing total Cr in excess of the 370 mg/ kg effects range-median (ER-M) sediment quality guideline. The Cr(VI) concentrations in sediments, however, were markedly lower, ranging from 0.10 to 0.38 mg/kg with Cr(VI) not detected in 14 of the 22 stations. Porewater concentrations, both for total Cr and Cr(VI), were quite low, with total Cr ranging from 0.20 to 2.16 μg/L and Cr(VI) ranging from 0.73 to 1.17 μg/L. The Cr(VI)-reducing capacity of the sediments, based on a sediment-spiking experiment, was found to be strongly correlated with the acid volatile sulfides content of the sediment. Overall, our results provide field validation of the hypothesis that Cr(VI) will not persist in sediments with excess acid volatile sulfides. Given the low concentrations of Cr(VI) in sediment and porewater, it appears unlikely that Cr in Baltimore Harbor sediments contributes appreciably to previously observed sediment toxicity.
Adsorption of arsenic to magnetite nanoparticles: Effect of particle concentration, pH, ionic strength, and temperature
Authors: Shipley Heather J. , Yean Sujin , Kan Amy T. , Tomson Mason B.
Published: October 2008

Little work has been conducted on the adsorption of arsenic to the mixed iron [Fe(II)/(III)] oxide magnetite and the effect that environmental parameters, such as pH, ionic strength, and temperature, have on adsorption. Magnetite nanoparticles are unique because of their affinity for both arsenate and arsenite and increased adsorption capacity from their bulk counterparts. This article shows the effect of various magnetite nanoparticle concentrations on arsenic adsorption kinetics. The adsorption data show the ability of the magnetite nanoparticles to remove arsenate and arsenite from solution in both synthetic and natural waters, and the data fit a first-order rate equation. Because of the increased surface area of these particles, less than 1 g/L of magnetite nanoparticles was needed. The results suggest that arsenic adsorption to the nanoparticles was not significantly affected by the pH, ionic strength and temperature in the ranges tested, which are typical of most potable water sources.
Addressing arsenic bioaccessibility in ecological risk assessment: A novel approach to avoid overestimating risk
Authors: Ollson Christopher A. , Koch Iris , Smith Paula , Knopper Loren D. , Hough Chris , Reimer Ken J.
Published: October 2008

The risk of arsenic exposure to deer mice (Peromyscus maniculatus) living in areas of naturally and anthropogenically elevated arsenic levels was determined using three separate calculations of arsenic daily intake: Estimated daily intake (EDI), bioaccessible EDI (BEDI), and actual daily intake (ADI). The present work is of particular interest, because the risk assessments were determined for animals naturally exposed to arsenic. Gastric fluid extraction was used to obtain bioaccessibility data for soil and plant samples collected from three study sites (background, mine forest, and tailings) in Yellowknife (NT, Canada). Calculations using the EDI indicated that deer mice living in tailings habitat (average soil arsenic concentration, 1,740 ± 2,240 μg/g) should have been experiencing serious health effects as a result of their exposure to arsenic. Using BEDI and ADI in the risk assessment calculation, however, resulted in an order-of-magnitude decrease in calculated risk. In addition, results calculated using the BEDI and ADI were not significantly different, suggesting that using bioaccessibility provides a more realistic estimate of potential risk. The present results provide evidence that the use of EDI in traditional risk assessments may seriously overestimate the actual risk, which in some instances may result in expensive and unnecessary clean-up measures.
Development of negligible depletion hollow fiber–protected liquid-phase microextraction for sensing freely dissolved triazines
Authors: Hu Xialin , Liu Jingfu , Jönsson Jan Å. , Jiang Guibin
Published: October 2008

A new sampling method, termed negligible depletion hollow fiber–protected liquid-phase microextraction, was developed for sensing the freely dissolved concentration (Cfree) and evaluating the availability of atrazine (ATR), desethyl atrazine (DEA), and simazine (SIM) in water. The sampling device was prepared by impregnating 1-octanol to both the pores and the lumen of a piece of polypropylene microporous hollow fiber membrane. After equilibrium and negligible depletion extraction, the 1-octanol in the lumen of the hollow fiber (10 μl) was collected for determination of triazines. Determination of Cfree and the distribution coefficient to 1-octanol (DOW) can be performed with this technique. A wide linear working range (1–200 μg/L) and low detection limits (0.1–1 μg/L) were obtained for triazines. Measured log DOW values of DEA (1.44 ± 0.04), SIM (2.06 ± 0.06), and ATR (2.33 ± 0.05) agreed well with those reported in the literature. The measured DOW values were independent of the chemical concentration and sample pH (pH 3–10) and negligibly affected by the sample salinity (0–500 mM), suggesting that environmentally relevant pH and salinity have no significant effects on the availability of triazines. Although a slight (≤31%) increase of Cfree was observed, one-way analysis of variance indicated the Cfree of triazines were not significantly affected by the presence of Aldrich humic acid, Acros humic acid, and bovine albumin V (dissolved organic carbon [DOC], 0–100 mg/L). From 3 to 36% of the spiked triazines, however, were found to associate with the dissolved organic matter (DOM) in surface-water samples (DOC, 32.0–61.9 mg/L), suggesting the origin of the DOM is a key parameter in determining its association with and, thus, the availability of triazines.
Enantioselectivity in the immunotoxicity of the insecticide acetofenate in an in vitro model
Authors: Zhao Meirong , Liu Weiping
Published: October 2008

Chiral pesticides with an asymmetrical center in their molecular structures possess enantioselectivity, not only in their pesticidal activities toward targeted organisms but also in toxicities to nontargeted organisms. Despite the fact that chiral pesticides deserve particular attention because of their ubiquitous presence in living and working environments, there has been limited research into their enantioselectivity in chronic toxicity. The immunotoxicity of chiral pesticides with respect to enantioselectivity has not been studied before. In this study, the role of enantioselectivity in the immunotoxicity of acetofenate (AF), an organochlorine insecticide, was investigated in an in vitro macrophage cell line model. Results of the cytotoxicity assay showed a clear dose-dependent growth inhibition effect of AF with enantioselectivity on RAW264.7 cells. S-(+)-AF was clearly more toxic to macrophages than R-(−)-AF and rac-AF. This work also demonstrated that S-(+)-AF possesses the strongest effects in induction of intracellular reactive oxygen species, DNA damage, and upregulation of p53 gene expression. These results, for the first time, show stark selectivity between enantiomers in their ability to induce macrophage-involved immunotoxicity of AF. These results suggest that assessment of the environmental safety and health risk of chiral contaminants should consider the role of enantioselectivity in immunotoxicity. In addition, our study will improve the knowledge of the role of enantioselectivity in immunotoxicity of chiral contaminants.
Disposition of perfluorinated acid isomers in sprague-dawley rats; Part 2: Subchronic dose
Authors: De Silva Amila O. , Benskin Jonathan P. , Martin Leah J. , Arsenault Gilles , McCrindle Robert , Riddell Nicole , Martin Jonathan W. , Mabury Scott A.
Published: October 2008

Two major industrial synthetic pathways have been used to produce perfluorinated acids (PFAs) or their precursors: Telomerization and electrochemical fluorination (ECF). Products of telomer and ECF origin can be distinguished by structural isomer profiles. A mixture of linear and branched perfluoroalkyl isomers is associated with ECF. Telomer products characteristically consist of a single perfluoroalkyl geometry, typically linear. In biota, it is unclear if the isomer profile is conserved relative to the exposure medium and hence whether PFA isomer profiles in organisms are useful for distinguishing environmental PFA sources. A companion study suggested isomer-specific disposition following a single oral gavage exposure to rats. To confirm these findings under a more realistic subchronic feeding scenario, male and female rats were administered PFA isomers by diet for 12 weeks, followed by a 12-week depuration period. The diet contained 500 ng/g each of ECF perfluorooctanoate (PFOA, ∼80% n-PFOA), ECF perfluorooctane sulfonate (PFOS, ∼70% n-PFOS), and linear and isopropyl perfluorononanoate (n- and iso-PFNA). Blood sampling during the exposure phase revealed preferential accumulation of n-PFOA and n-PFNA compared to most branched isomers. Female rats depurated all isomers faster than males. Both sexes eliminated most branched perfluorocarboxylate isomers more rapidly than the n-isomer. Elimination rates of the major branched PFOS isomers were not statistically different from n-PFOS. Two minor isomers of ECF PFOA and one branched PFOS isomer had longer elimination half-lives than the n-isomers. Although extrapolation of these pharmacokinetics trends in rats to humans and wildlife requires careful consideration of dosage level and species-specific physiology, cumulative evidence suggests that perfluorocarboxylate isomer profiles in biota may not be suitable for quantifying the relative contributions of telomer and ECF sources.
Estimated Occupational Risk from Bioaerosols Generated during Land Application of Class B Biosolids
Authors: Tanner Benjamin D. , Brooks John P. , Gerba Charles P. , Haas Charles N. , Josephson Karen L. , Pepper Ian L.
Published: October 2008

Some speculate that bioaerosols from land application of biosolids pose occupational risks, but few studies have assessed aerosolization of microorganisms from biosolids or estimated occupational risks of infection. This study investigated levels of microorganisms in air immediately downwind of land application operations and estimated occupational risks from aerosolized microorganisms. In all, more than 300 air samples were collected downwind of biosolids application sites at various locations within the United States. Coliform bacteria, coliphages, and heterotrophic plate count (HPC) bacteria were enumerated from air and biosolids at each site. Concentrations of coliforms relative to Salmonella and concentrations of coliphage relative to enteroviruses in biosolids were used, in conjunction with levels of coliforms and coliphages measured in air during this study, to estimate exposure to Salmonella and enteroviruses in air. The HPC bacteria were ubiquitous in air near land application sites whether or not biosolids were being applied, and concentrations were positively correlated to windspeed. Coliform bacteria were detected only when biosolids were being applied to land or loaded into land applicators. Coliphages were detected in few air samples, and only when biosolids were being loaded into land applicators. In general, environmental parameters had little impact on concentrations of microorganisms in air immediately downwind of land application. The method of land application was most correlated to aerosolization. From this large body of data, the occupational risk of infection from bioaerosols was estimated to be 0.78 to 2.1%/yr. Extraordinary exposure scenarios carried an estimated annual risk of infection of up to 34%, with viruses posing the greatest threat. Risks from aerosolized microorganisms at biosolids land application sites appear to be lower than those at wastewater treatment plants, based on previously reported literature.
Leaching Mechanisms of Cr(VI) from Chromite Ore Processing Residue
Authors: Wazne Mahmoud , Jagupilla Santhi Chandra , Moon Deok Hyun , Christodoulatos Christos , Koutsospyros Agamemnon
Published: October 2008

Batch leaching tests, qualitative and quantitative x‐ray powder diffraction (XRPD) analyses, and geochemical modeling were used to investigate the leaching mechanisms of Cr(VI) from chromite ore processing residue (COPR) samples obtained from an urban area in Hudson County, New Jersey. The pH of the leaching solutions was adjusted to cover a wide range between 1 and 12.5. The concentration levels for total chromium (Cr) and Cr(VI) in the leaching solutions were virtually identical for pH values >5. For pH values <5, the concentration of total Cr exceeded that of Cr(VI) with the difference between the two attributed to Cr(III). Geochemical modeling results indicated that the solubility of Cr(VI) is controlled by Cr(VI)‐hydrocalumite and Cr(VI)‐ettringite at pH >10.5 and by adsorption at pH <8. However, experimental results suggested that Cr(VI) solubility is controlled partially by Cr(VI)‐hydrocalumite at pH >10.5 and by hydrotalcites at pH >8 in addition to adsorption of anionic chromate species onto inherently present metal oxides and hydroxides at pH <8. As pH decreased to <10, most of the Cr(VI) bearing minerals become unstable and their dissolution contributes to the increase in Cr(VI) concentration in the leachate solution. At low pH (<1.5), Cr(III) solid phases and the oxides responsible for Cr(VI) adsorption dissolve and release Cr(III) and Cr(VI) into solution.
Spatial Variability of Atrazine and Metolachlor Dissipation on Dryland No‐tillage Crop Fields in Colorado
Authors: Bridges Melissa , Henry W. Brien , Shaner Dale L. , Khosla R. , Westra Phil , Reich Robin
Published: October 2008

An area of interest in precision farming is variable‐rate application of herbicides to optimize herbicide use efficiency and minimize negative off‐site and non‐target effects. Site‐specific weed management based on field scale management zones derived from soil characteristics known to affect soil‐applied herbicide efficacy could alleviate challenges posed by post‐emergence precision weed management. Two commonly used soil‐applied herbicides in dryland corn (Zea mays L.) production are atrazine and metolachlor. Accelerated dissipation of atrazine has been discovered recently in irrigated corn fields in eastern Colorado. The objectives of this study were (i) to compare the rates of dissipation of atrazine and metolachlor across different soil zones from three dryland no‐tillage fields under laboratory incubation conditions and (ii) to determine if rapid dissipation of atrazine and/or metolachlor occurred in dryland soils. Herbicide dissipation was evaluated at time points between 0 and 35 d after soil treatment using a toluene extraction procedure with GC/MS analysis. Differential rates of atrazine and metolachlor dissipation occurred between two soil zones on two of three fields evaluated. Accelerated atrazine dissipation occurred in soil from all fields of this study, with half‐lives ranging from 1.8 to 3.2 d in the laboratory. The rapid atrazine dissipation rates were likely attributed to the history of atrazine use on all fields investigated in this study. Metolachlor dissipation was not considered accelerated and exhibited half‐lives ranging from 9.0 to 10.7 d in the laboratory.
Genetic Screening in Infertile Mexican Men: Chromosomal Abnormalities, Y Chromosome Deletions, and Androgen Receptor CAG Repeat Length
Authors: Martínez‐Garza Sandra Guadalupe , Gallegos‐Rivas Mayra Celina , Vargas‐Maciel Marcos , Rubio‐Rubio Juan Manuel , de los Monteros‐Rodríguez Mario Espinosa , González‐Ortega Claudia , Cancino‐Villarreal Patricia , de Lara Luis G. Vazquez , Gutiérrez‐Gutiérrez Antonio Martín
Published: October 2008

ABSTRACT: In our study, we analyzed chromosomal abnormalities, Y chromosome deletions, androgen receptor CAG repeat length and their association with defective spermatogenesis in infertile Mexican men. Eighty‐two infertile patients and 40 controls were screened for karyotypic abnormalities, Y chromosome microdeletions, and CAG repeats. Nine infertile males (11%) carried chromosomal abnormalities and 10 (12.2%) presented Y chromosome microdeletions. The mean CAG repeat length was 21.6 and 20.88 base pairs in idiopathic infertile males and controls, respectively. Our results suggest that chromosomal aberrations and Y‐chromosomal microdeletions are related to male infertility in Mexican men. In addition, expansion of the CAG repeat segments of the androgen receptor is not correlated with male idiopathic infertility.
Testosterone and Erectile Dysfunction
Authors: Yassin Aksam A. , Saad Farid
Published: October 2008

ABSTRACT:Aging is associated with a decline in several important health factors in men, including libido. Serum testosterone concentrations also decrease with age, and many age‐related clinical features are closely associated with androgen deficiency, including erectile function (ED). Approximately 70% of ED is of organic origin, with the major risk factors being diabetes mellitus, hypercholesterolemia, smoking and chronic medical illnesses. These are also established risk factors for atherosclerosis, which is the predominant predisposing factor of vasculogenic ED. The introduction of phosphodiasterase‐5 (PDE‐5) inhibitors for the treatment of ED made a significant impact both in terms of clinical efficacy, and increasing the awareness of the condition. In spite of this, some patients fail to respond to PDE‐5 inhibitors alone. Both animal and clinical studies indicate that testosterone therapy improves both erectile function and the response to PDE‐5 inhibitors in patients with ED and hypogonadism. Indeed, interventional studies demonstrate that testosterone replacement therapy improves erectile function in hypogonadal men who have previously failed to respond to PDE‐5 inhibitors alone. Furthermore, it has been demonstrated that the full therapeutic potential of PDE5 inhibitors will only become manifest in a eugonadal state. Recent studies have demonstrated a close relationship between testosterone and ED and suggest that testosterone therapy may be a valuable option for an increasing number of affected men. European guidelines recommend that all men presenting with ED should have their testosterone concentrations measured.
Effects of Testosterone on Antioxidant Systems in Male Secondary Hypogonadism
Authors: Mancini Antonio , Leone Erika , Festa Roberto , Grande Giuseppe , Silvestrini Andrea , de Marinis Laura , Pontecorvi Alfredo , Maira Giulio , Littarru Gian Paolo , Meucci Elisabetta
Published: October 2008

ABSTRACT: Oxidative stress is involved both in metabolic syndrome and male infertility. Hypogonadism is also associated with increased risk for cardiovascular disease. To investigate the role of gonadal steroids in systemic antioxidant regulation, we determined plasma CoenzymeQ10 (CoQ10) and total antioxidant capacity (TAC) in postsurgical hypopituitaric patients. Twenty‐six patients aged 28–55 years were studied 6–12 months after surgery. CoQ10 levels were measured by high‐performance liquid chromatography and TAC by spectroscopy with the use of the mioglobin‐H2O2 system, which, in interacting with chromogen 2,2I‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonate), generates a radical after a latency time (LAG) that is proportional to antioxidant content. Sixteen patients presented low testosterone values; in 10 patients hypogonadism was isolated, and in 6 patients hypothyroidism also was present. CoQ10 levels were significantly lower in isolated hypogonadism than in normogonadism. Testosterone treatment, performed in those patients with isolated hypogonadism, induced a significant enhancement both in CoQ10 level and LAG. CoQ10 and LAG values correlated significantly, suggesting an interrelationship between different antioxidants. Our data suggest that hypogonadism could represent a condition of oxidative stress, in turn related with augmented cardiovascular risk.
Dietary‐Induced Hyperthyroidism Marginally Affects Neonatal Testicular Development
Authors: Rijntjes Eddy , Wientjes Anna T. , Swarts Hans J. M. , de Rooij Dirk G. , Teerds Katja J.
Published: October 2008

ABSTRACT: The objective of this study was to determine whether dietary‐induced mild fetal/neonatal hyperthyroidism influenced the initiation of spermatogenesis and the development of the adult‐type Leydig cell population. Previously, the effects of neonatally induced hyperthyroidism have been investigated in rats using rather high doses (5 to 10 μg/100 g body weight) of tri‐iodothyronine, which not only influenced testicular development, but also negatively affected the general body condition of the animals. To induce hyperthyroidism the diet of the dams was supplemented with 15 μg thyroxine (T4)/100 g body weight 2 weeks prior to mating and the dams and their offspring were kept on this diet until sacrifice. Pups were killed between days 7 and 64 after birth. At the age of 12 days plasma thyroid‐stimulating hormone (TSH) levels tended to be lower in hyperthyroid pups, and from the age of 15 days onwards plasma TSH levels were significantly lower in hyperthyroid animals. Concomitantly, plasma T4 levels were significantly elevated. From the age of 12 days onwards, plasma follicle‐stimulating hormone levels were lower in hyperthyroid animals compared with age‐matched control groups. Sertoli cell differentiation did not seem to be influenced by the mild hyperthyroid condition, as no difference in tubule lumen formation was observed between euthyroid and hyperthyroid animals. Nevertheless, a small effect on the progression of spermatogenesis was observed 15 days after birth, as the most advanced type of germ cells in the control testis were pachytene spermatocytes, whereas in the hyperthyroid testis these were leptotene and zygotene spermatocytes. Leydig cell proliferation was decreased in the hyperthyroid pups at the age of 15 days and slightly elevated at later ages, suggesting a possible slower onset of the proliferative activity of these cells than in the euthyroid control animals. Taken together, the present results suggest that even mild dietary‐induced hyperthyroidism transiently affects the development of the adult‐type Leydig cell population as well as the initial progression of spermatogenesis.
Testosterone Improves Erectile Function in Hypogonadal Patients With Venous Leakage
Authors: Kurbatov Dmitry , Kuznetsky Jury , Traish Abdulmaged
Published: October 2008

ABSTRACT: The goal of this study was to assess the therapeutic benefits of long‐acting testosterone therapy in hypogonadal patients with erectile dysfunction (ED). We recruited 29 patients with ED, ranging in age from 32 to 65 years (mean ± SD, 47 ± 9.7 years), with low plasma testosterone, who did not respond to phosphodiesterase type 5 inhibitor therapy. To evaluate penile arterial and venous blood flow, we employed duplex Doppler ultrasonography. For confirmation of diagnosis of venous leakage, pharmacocavernosography was carried out in 9 patients and magnetic resonance imaging with intracavernous contrast enhancement was carried out in 8 patients. All patients were treated with 1000 mg injectable testosterone undecanoate on day 1, followed by another injection after 6 weeks and every 3 months thereafter, in accordance with Nebido therapy protocol. Plasma testosterone levels were determined in all patients at baseline and after 18 and 30 weeks of testosterone treatment. The International Index of Erectile Function (IIEF‐5) was administered at baseline and after 18 and 30 weeks of testosterone treatment. At baseline total testosterone ranged from 7 to 11.8 nmol/L (200 to 345 ng/dL) in 25 patients. Eighteen and 30 weeks after testosterone treatment, the mean testosterone plasma levels were 18 and 21.5 nmol/L (520 and 625 ng/dL), respectively. After 18 and 30 weeks of testosterone treatment, 20 out of the 29 patients demonstrated marked improvement in erectile function domain, as assessed by the IIEF‐5. This was also associated with diminution of venous leakage. We suggest that, in hypogonadal men with ED, testosterone therapy improves erectile function in patients with ED and venous leakage.
Laparoscopic Management of Müllerian Duct Remnants: Four Case Reports and Review of the Literature
Authors: Luo Jun‐Hang , Chen Wei , Sun Jun‐Jie , Xie Dan , Mo Jia‐Cong , Zhou Li , Lu Jian
Published: October 2008

ABSTRACT: Several experiences with laparoscopic management of müllerian duct remnants (MDRs) have been reported to date. This report outlines our experience and reviews the present literature to evaluate the results of laparoscopic excision of MDR. Between April 2003 and December 2007, 4 male patients (age range, 6–20 years) with MDR underwent laparoscopic excision in our center. A literature search revealed 5 additional reports of laparoscopic excision of MDR, comprising 13 patients (age range, 1.5–48 years). For the 4 patients in our center, the operative time was 135–200 minutes (mean, 159 minutes) and the estimated blood loss was 20–100 mL (mean, 48 mL). For the 13 patients in the literature reviewed, the operative time was 105–360 minutes (mean, 190 minutes) and the estimated blood loss was 50–200 mL. All of these 17 patients recovered uneventfully with no complications. A small prostatic diverticulum had been found in 1 case at 6 years postoperatively; no recurrent evidence or voiding dysfunction had been found in the other 16 patients during 3–50 months of follow‐up. No patient had required any further operative therapy. Laparoscopic excision of MDR is a safe and effective surgical procedure, associated with minimal invasion, minimal postoperative morbidity, and rapid recovery for the patient.
Plan B
Authors: Zingales Luigi
Published: October 2008

As Paulson's and the world's confidence in the original rescue plan has waned, Luigi Zingales, a finance professor from the University of Chicago, who early on opposed the Paulson plan, presents Plan B. Plan B is an innovative approach for dealing directly with the foreclosure crises which avoids the costs and moral hazard problems of other proposals, together with a prepackaged bankruptcy/recapitalization proposal inspired by Lucian Bebchuk.
Chimeric Maternal Cells with Tissue-Specific Antigen Expression and Morphology Are Common in Infant Tissues
Authors: Stevens Anne M. , Hermes Heidi M. , Kiefer Meghan M. , Rutledge Joe C. , Lee Nelson J.
Published: October 2008

Maternal microchimerism (MMc) has been purported to play a role in the pathogenesis of autoimmunity, but how a small number of foreign cells could contribute to chronic, systemic inflammation has not been explained. Reports of peripheral blood cells differentiating into tissue-specific cell types may shed light on the problem in that chimeric maternal cells could act as target cells within tissues. We investigated MMc in tissues from 7 male infants. Female cells, presumed maternal, were characterized by simultaneous immunohistochemistry and fluorescence in situ hybridization for X- and Y-chromosomes. Maternal cells constituted 0.017% to 1.9% of parenchymal cells and were found in all infants in liver, pancreas, lung, kidney, bladder, skin, and spleen. Maternal cells were differentiated: maternal hepatocytes in liver, renal tubular cells in kidney, and β-islet cells in pancreas. Maternal cells were not found in areas of tissue injury or inflammatory infiltrate. Maternal hematopoietic cells were found only in hearts from patients with neonatal lupus. Thus, differentiated maternal cells are present in multiple tissue types and occur independently of inflammation or tissue injury. Loss of tolerance to maternal parenchymal cells could lead to organ-specific “auto” inflammatory disease and elimination of maternal cells in areas of inflammation.
Career choice motivations of medical students and some characteristics of the decision process in Hungary
Authors: Molnár Regina , Nyári Tibor , Hazag Anikó , Csinády Adriána , Molnár Péter
Published: October 2008

The changed circumstances of medical work, raises the question of how socio-economic changes over the last few decades has affected the professional socialisation of medical students. This paper explores the career choice motivations of medical students, as well as some characteristics of the process of making that choice and their effects on professional socialisation. The study was carried out with a self-administered questionnaire with 503 students in general medicine, randomly selected from two Hungarian Medical Schools. More than half of the students contemplated becoming a doctor as early as in their childhood. Their final decision was typically made in high school. Significant differences can be demonstrated in professional socialisation between those individuals identifying with the profession in early childhood and others turning to the profession later. Altruistic motivations were the most significant career choice reasons. In conclusions, the medical career choice must have deeper roots, yielding to an evolutionary psychological analysis as well, one aspect of which is altruism.
Diastolic blood pressure cut-off predicts major cerebrovascular events after minor ischaemic stroke: a post-hoc modelling study
Authors: Atanassova Penka , Chalakova Nedka , Dimitrov Borislav
Published: October 2008

Only few follow-up studies have studied in detail the role of most important risk factors, but no reports were found on critical values (cut-offs) for such factors in prospectively predicting cerebrovascular events (CVE) in patients with minor ischaemic stroke (MIS). Estimates of predictive importance of such cut-offs may better inform and contribute to optimize treatment. This was a post-hoc modelling study with unique data from Bulgaria on 54 consecutive patients with MIS, aged ł 40, followed for 12 months for nonfatal or fatal CV events. A set of routine clinical demographic and known risk factors (SBP, DBP, HDL cholesterol, etc.) were explored using univariate statistics and multivariate regression models to identify the most important independent predictors of secondary CVE. An artificial neural network (ANN) model, irrespective of usual statistical constraints, also confirmed the specific role and importance of identified predictors. A receiver operating characteristics (ROC) curve and stratified survival analyses were used to define the best cut-off of most important predictors and validate the final model. During follow-up period of 11.1±2.4 months, 8 secondary CV events (14.8%) were observed only in males with MIS at the 5.8±2.7 months mark. No difference in age of patients with CV event (61.1±12.6 years) vs. those without (62.1±9.6 years) was found (p>0.05). The one-year risk for CVE was.15% (95%CI 7.1, 27.7%). The two most important risk factors in patients with versus without CV events were acute MIS onset (62.5 vs. 13.0%) and mean DBP at day 30 post-MIS (101.3±9.9 vs. 92.3±10.8 mmHg), with a relative importance by ANN of 20.92 versus 15.9 points, respectively. At multivariate logistic analysis only MIS onset and DBP were independently associated with the risk for secondary CVE (79.6% model accuracy, p
model=0.0015). An increase of DBP with 1 mmHg was associated with 8% higher risk of CVE [adjusted OR=1.08 (95%Cl 1.004, 1.158)]. With this method, a novel cut-off predictive DBP value of 95 mmHg (ROCAUC=0.79, 95%Cl 0.60, 0.99, p=0.009) for CV events in patients with MIS has been found. In conclusions the new DBP cut-off (sensitivity >87%, specificity >69%) clearly discriminated between absence and presence of secondary CVE as also confirmed by stratified survival analysis (7 vs. 1 events, plog-rank =0.0103). This cut-off may be applied to better precisely evaluate and define, as earlier as possible, MIS patients at increased risk of secondary CV events.
Effect of tonsillectomy and/or adenoidectomy on pulmonary arterial pressure in adults
Authors: Abdelwhab Saeed , Dessoukey Khaled. , Lotfy Gamal , Alsaeed Ashraf , Anwar Hesham
Published: October 2008

The aim of the study was to determine the mean pulmonary pressure in adult with hypertrophic tonsils and adenoids and to clarify whether tonsillectomy and adenoidectomy has any effect on mean pulmonary arterial pressure of these adult. The study was carried out on 50 patients with diagnosis of upper airway obstruction resulting from hypertrophied tonsils and adenoids (group1). 25 adults were assigned as control with similar age and sex distribution (group2). For study subjects Routine general Examinations, BMI, ECG, Chest X ray, Arterial blood gases and Echocardiography were done. Mean pulmonary arterial pressure was measured by using Doppler Echocardiography preoperatively and mean 3–4 months postoperatively in all subjects. Elevated PAP (pulmonary artery pressure) was found in 15 patients (30%) in group 1 preoperatively. Mean PAP was 28.34 ±5.11 mmHg preoperative in group 1 and 19.84 ± 5.0 mmHg in group 2 (p <0.001). PAP decrease to 22.38 ±4.28 mmHg postoperatively in group 1 (p <0.001). Arterial oxygen saturation (spo2%) increase from 93.5 ± 1.9% preoperatively to 95.3 ± 1.3% post operatively (p < 0.001). percent reduction of PAP postoperatively correlates to age (t=−2.3, p= 0.02), preoperative PAP (p =0.01) but no correlation was found with BMI. In conclusions, this Study showed that obstructed adenoid and hypertrophy of tonsils causes higher mean pulmonary artery pressure in adult & revealed that tonsil& adenoid is effective therapeutic measure in such patients. With early intervention is necessary to avoid progressive cardiopulmonary disease.
Eisenhower's 1955 heart attack: Medical treatment, political effects, and the “behind the scenes” leadership style
Authors: Gilbert Robert E.
Published: October 2008

During his first term as President of the United States, Dwight D. Eisenhower suffered several serious illnesses. Particularly important was the massive heart attack he experienced in the fall of 1955. Drawing on primary sources as well as prior scholarship, this article analyzes varying interpretations of Eisenhower's 1955 medical treatment in light of his previous illnesses and their management. It explores the handling of public disclosure by the White House, by Eisenhower himself, and by his medical team. And it reconsiders Republican strategists' efforts to allay public concerns about the President's health. Current understanding is called into question in several respects. Although it sharpened speculation about his fitness and willingness to run in the 1956 presidential campaign, the 1955 heart attack made Eisenhower more likely, rather than less likely, to run. Although often sick, and in several instances critically so, Eisenhower was clearly the dominant player — intentionally “behind the scenes” — both in the management of his illnesses and in the health-perceptual aspects of his drive toward a second term. These findings should lead us to a better reading of Eisenhower as a president and to a better appreciation of health's linkage to legacy in presidential politics.
Review Essay: Lynn and Vanhanen, IQ and Global Inequality
Authors: Somit Albert , Peterson Steven A.
Published: October 2008

IQ and Global Inequality is a sequel to the authors' earlier IQ and the Wealth of Nations wherein they argued that “… national differences in intelligence are an important factor contributing to differences in national wealth and rates of economic growth” (p. 2). Or, later more precisely stated, that “… national IQ is the single most powerful explanatory variable, but because the explained part of the variation does not rise higher than 40–60 percent, this explanation leaves room for other explanatory factors”(p. 13). Not surprisingly, even so qualified, this thesis triggered a “mixed reception.” As the authors relate with refreshing candor, some of the reviewers denounced them for “jumping to conclusions,” took issue with their “relatively weak statistical evidence and dubious presumptions,” found the study “neither methodologically nor theoretically convincing,” and dismissed the evidence as “virtually meaningless” (p. 3).
Radiographic evaluation of trigeminal neurovascular compression in patients with and without trigeminal neuralgia
Authors: Miller Jonathan P. , Acar Feridun , Hamilton Bronwyn E. , Burchiel Kim J.
Published: October 2008

Object

Neurovascular compression (NVC) of the trigeminal nerve is associated with trigeminal neuralgia (TN), but also occurs in many patients without facial pain. This study is designed to identify anatomical characteristics of NVC associated with TN.

Methods

Thirty patients with Type 1 TN (intermittent shocklike pain) and 15 patients without facial pain underwent imaging for analysis of 30 trigeminal nerves ipsilateral to TN symptoms, 30 contralateral to TN symptoms, and 30 in asymptomatic patients. Patients underwent 3-T MR imaging including balanced fast-field echo and MR angiography. Images were fused and reconstructed into virtual cisternoscopy images that were evaluated to determine the presence and degree of NVC. Reconstructed coronal images were used to measure nerve diameter and crosssectional area.

Results

The incidence of arterial NVC in asymptomatic nerves, nerves contralateral to TN symptoms, and nerves ipsilateral to TN symptoms was 17%, 43%, and 57%, respectively. The difference between symptomatic and asymptomatic nerves was significant regarding the presence of NVC, nerve distortion, and the site of compression (p < 0.001, Fisher exact test). The most significant predictors of TN were compression of the proximal nerve (odds ratio 10.4) and nerve indentation or displacement (odds ratio 4.3). There was a tendency for the development of increasingly severe nerve compression with more advanced patient age across all groups. Decreased nerve size was observed in patients with TN but did not correlate with the presence or extent of NVC.

Conclusions

Trigeminal NVC occurs in asymptomatic patients but is more severe and more proximal in patients with TN. This information may help identify patients who are likely to benefit from microvascular decompression.
Completely endoscopic resection of intraparenchymal brain tumors
Authors: Kassam Amin B. , Engh Johnathan A. , Mintz Arlan H. , Prevedello Daniel M.
Published: October 2008

Object

The authors introduce a novel technique of intraparenchymal brain tumor resection using a rod lens endoscope and parallel instrumentation via a transparent conduit.

Methods

Over a 4-year period, 21 patients underwent completely endoscopic removal of a subcortical brain lesion by means of a transparent conduit. Image guidance was used to direct the cannulation and resection of all lesions. Postoperative MR imaging or CT was performed to assess for residual tumor in all patients, and all patients were followed up postoperatively to assess for new neurological deficits or other surgical complications.

Results

The histopathological findings were as follows: 12 metastases, 5 glioblastomas, 3 cavernous malformations, and 1 hemangioblastoma. Total radiographically confirmed resection was achieved in 8 cases, near-total in 6 cases, and subtotal in 7 cases. There were no perioperative deaths. Complications included 1 infection and 1 pulmonary embolus. There were no postoperative hematomas, no postoperative seizures, and no worsened neurological deficits in the immediate postoperative period.

Conclusions

Fully endoscopic resection may be a technically feasible method of resection for selected subcortical masses. Further experience with this technique will help to determine its applicability and safety.
Clinical Presentation of Dengue in 150 Admitted Cases in Dhaka Medical College Hospital
Authors: Azad Md Abul Kalam , Mohammad Hanif , Alam Md Billal , Saha Anup Kumar , Ahmed Tofayel
Published: October 2008

Dengue fever was not recognized as a major public health hazard in Bangladesh before 1999 outbreak, so there was little evidence and awareness in this regard. A prospective observational study was carried out to determine the risk group of patients suffering from dengue syndrome; clinical parameters of the subjects for hospitalization and the pattern of presentation of dengue fever in hospital care in different medicine units of Dhaka Medical College hospital from July 2000 to March 2001. Total 150 cases were selected randomly and diagnosed clinically as dengue, and were classified into 3 groups, i.e. 18 cases of classical dengue fever, 127 cases of dengue hemorrhagic fever (DHF-I and DHF-II) and 5 cases of dengue shock syndrome (DSS), and were discharged uneventfully. Among them 125(83.3%) were male and 25(16.7%) were female. Mean ages of the subjects were 26.75 Â±3.69, 27.59 Â± 1.18 and 10.67 Â± 2.33 years in respective groups. Mean temperature was 103.45Â±0.28, 103.08Â±0.13, and 104.00Â±1.00 Â°F with mean duration was 5.50Â±0.51 days, 6.12Â±0.2 days, and 5.00Â±1.15 in respective groups. Majority had profound weakness, headache, myalgia, anorexia, nausea, and vomiting. Diarrhoea, abdominal pain, organomegaly, ascites, and pleural effusion were frequent complaints in group-3 patients, whereas infrequent complaints in other groups. Haemorrhagic manifestations were common in group 2 and 3 patients, melaena being the most common manifestations. Â  DOI = 10.3329/jom.v7i1.1355 J MEDICINE 2006; 7: 3-9