bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral Testosterone in Oil: Pharmacokinetic Effects of 5α Reduction by Finasteride or Dutasteride and Food Intake in Men
Authors: Amory John K. , Page Stephanie T. , Bremner William J.
Published: January 2006

ABSTRACT: Oral administration of 400 mg of testosterone (T) in oil, when combined with the 5α reductase inhibitor dutasteride (D), elevates serum T in medically castrated men to the normal range. In this study, we sought to determine the impact of 1) finasteride (F) and 2) food intake on the serum T and dihydrotestosterone (DHT) levels observed after the oral administration of T in oil. Therefore, we conducted a pharmacokinetic study of oral T in oil, alone or with D or F, in the fasting and fed states in normal men whose endogenous T production was suppressed by the GnRH antagonist acyline. After acyline administration, 7 healthy men (mean age 31 ± 8 years) were sequentially administered five 400‐mg doses of oral T in sesame oil once daily. The first dose of oral T (T‐alone) in oil was given while fasting without F or D. The second (fasting) and third (fed) doses were administered after pretreatment with F (T + F). Four days later, the fourth (fasting) and fifth (fed) doses were administered after pretreatment with D (T + D). Blood samples for measurement of serum T and DHT were obtained before T dosing and 0.5, 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after each administration. In the fasting state, 24‐hour area‐under‐the‐curve of serum T after oral T administration was significantly greater with coadministration of either D or F compared with T‐alone (126 ± 36 nmol‐h/L [T‐alone] vs 287 ± 98 nmol‐h/L [T + F] vs 236 ± 82 nmol‐h/L [T + D]; P < .05 for T + F and T + D vs T‐alone). Administration of the T with food nonsignificantly decreased serum T levels compared with fasting administration. The administration of oral T in oil combined with either F or D results in serum T levels adequate to treat men with testicular failure. Additional studies of the combination of oral T in oil with 5α‐reductase inhibitors as a novel form of oral T therapy are warranted.
Seasonal Changes of Neutral α‐Glucosidase Activity in Human Semen
Authors: Henkel Ralf , Maaß Gesa , Schuppe Hans‐Christian , Jung Andreas , Schubert Jörg , Schill Wolf‐Bernhard
Published: January 2006

ABSTRACT: Although there are contradictory reports, the biochemical evaluation of the seminal activity of neutral α‐glucosidase (NAG) has repeatedly been described as an important parameter to test epididymal patency and is recommended by the WHO. Because, for a number of diagnostic parameters, seasonal variations have been described even in the human, it was the aim of this study to investigate possible circannual changes of NAG. This is an important aspect of andrological diagnosis, as seasonal changes of specific diagnostic parameters might have an impact on the accuracy and predictive power of these parameters, which in turn might have an effect on the therapeutic concept for the patients. In a total of 473 patients, sperm concentration, volume of the ejaculate, total motility, progressive motility, pH value, number of peroxidase‐positive cells, concentration of fructose, and NAG as functional markers of the seminal vesicles and the epididymis, respectively, were analyzed according to standard procedures. Seminal activity of NAG was significantly correlated with the sperm concentration (P < .0001), ejaculate volume (P < .0001), and the pH (P = .0025). Moreover, significant (P = .0008) seasonal changes in the activity of seminal NAG with the maximum in spring (76.87 mU/ejaculate) and the minimum in autumn (58.55 mU/ejaculate) were found. The incidence of low‐ranged activity of the enzyme was 9.2% in spring, while it was 20.3% in autumn. Thus, our data clearly demonstrate circannual changes of the seminal activity of neutral α‐glucosidase. This in turn has clinical impact as the predictive power of the test system changes throughout the year.
Comparison of Chromatin Assays for DNA Fragmentation Evaluation in Human Sperm
Authors: Chohan Kazim R. , Griffin Jeanine T. , Lafromboise Marie , De Jonge Christopher J. , Carrell Douglas T.
Published: January 2006

ABSTRACT: Sperm chromatin integrity is vital for successful pregnancy and transmission of genetic material to the offspring. We evaluated chromatin integrity in sperm from 60 infertile men and 7 fertile donors comparing the sperm chromatin structure assay (SCSA), TdT‐mediated‐dUTP nick end labeling (TUNEL), the sperm chromatin dispersion (SCD) test, and acridine orange staining technique (AOT). The TUNEL and SCD assays showed a strong relationship with the SCSA (r > .866; P < .001) for sperm DNA fragmentation, both in infertile men and donors of known fertility. AOT did not show any relationship with SCSA. The breakdown of the DNA fragmentation index (DFI) into 3 categories (≤15%, >15%‐<30%, and ≥30%) showed that the SCSA, TUNEL, and SCD test predict the same levels of DNA fragmentation. AOT consistently showed higher levels of DNA fragmentation for each DFI category. DNA fragmentation in sperm between infertile men and donor sperm was significantly different (P < .05) under SCSA (22.0 ± 1.6 vs 11.8 ± 1.4), TUNEL (19.5 ± 1.3 vs 11.1 ± 0.9) and SCD (20.4 ± 1.3 vs 10.8 ± 1.1), respectively. DNA fragmentation in sperm evaluated by AOT did not differ (P > .05) between infertile men (31.3 ± 2.4) and donors (32.7 ± 4.8). AOT showed extreme variations for sperm DNA fragmentation in semen from both infertile men and donors. The problems of indistinct colors, rapid fading, and the heterogeneous staining were also faced. In conclusion, SCSA, TUNEL, and SCD show similar predictive values for DNA fragmentation, and AOT shows variable and increased levels of DNA fragmentation, which makes it of questionable value in clinical practice.
Psycho‐Biological Correlates of Free‐Floating Anxiety Symptoms in Male Patients With Sexual Dysfunctions
Authors: Corona Giovanni , Mannucci Edoardo , Petrone Luisa , Ricca Valdo , Balercia Giancarlo , Giommi Roberta , Forti Gianni , Maggi Mario
Published: January 2006

ABSTRACT: Anxiety has a relevant impact on everyday life, including sexual life, and therefore is considered the final common pathway by which social, psychological, and biological stressors negatively affect sexual functioning. The aim of this study is to define the psycho‐biological correlates of free‐floating anxiety in a large sample of patients complaining of erectile dysfunction (ED)‐based sexual problems. We studied a consecutive series of 882 ED patients using SIEDY©, a 13‐item structured interview, composed of 3 scales that identify and quantify organic, relational, and intrapsychic domains. MHQ‐A scoring from Middlesex Hospital Questionnaire (MHQ) was used as a putative marker of free‐floating anxiety symptoms (AS). Metabolic and hormonal parameters, nocturnal penile tumescence (NPT) test, and penile Doppler ultrasound (PDU) examination were also performed. MHQ‐A score was significantly higher in patients complaining of difficulties in maintaining erection and in those reporting premature ejaculation (6.5 ± 3.3 vs 5.8 ± 3.3 and 6.6 ± 3.3 vs 6.1 ± 3.3, respectively; both P < .05). Moreover, ASs were significantly correlated to life stressors quantified by SIEDY© scale 2 (relational component) and scale 3 (intrapsychic component) scores, as dissatisfaction at work or within the family or couple relationships. Among physical, biochemical, or instrumental parameters tested, only end‐diastolic velocity at PDU was significantly (P < .05) related to ASs. In conclusion, in patients with ED‐based sexual problems, ASs are correlated to many relational and life stressors. Conversely, organic problems are not necessarily associated with MHQ‐A score.
The Relationship Between Human Semen Characteristics and Sperm Apoptosis: A Pilot Study
Authors: Chen Zuying , Hauser Russ , Trbovich Alexander M. , Shifren Jan L. , Dorer David J. , Godfrey‐Bailey Linda , Singh Narendra P.
Published: January 2006

ABSTRACT: This work was undertaken to explore the association between human semen characteristics and apoptosis in ejaculated sperm. We collected semen samples from 23 consecutive male patients who presented to the Andrology Laboratory at Massachusetts General Hospital (MGH) for routine semen analysis. Sperm concentration and motility were measured using computer‐assisted sperm analysis. Morphology was assessed using Tygerberg strict criteria. The DNA diffusion assay was used to assess the percentage of apoptosis in ejaculated sperm. In this assay, cells were mixed with agarose and placed into a microgel on a microscopic slide. The cells were stained with YOYO‐1 dye, and apoptotic cells were viewed under a fluorescent microscope. Among 23 men, the mean (SD) sperm concentration, percent motility, percent progressive motility, and normal morphology were 125.5 (92.3) million/mL, 45.6% (22.2), 28.4% (15.2), and 8.0 (4.6), respectively. The mean (SD) percent of apoptosis in ejaculated sperm was 8.3% (6.2) with a range from 1.1% to 20.1%. There were inverse associations between percent apoptosis and sperm motility (P = .0025), progressive motility (P = .0051), and morphology with a normal or good pattern of fertilization by Kruger strict criteria (P = .0045), and a positive relationship between percent apoptosis and sperm tail defects (P = .0053). In ejaculated semen, the percent sperm apoptosis was associated with several measures of semen quality.
Analysis of Outcomes of Cryopreserved Surgically Retrieved Sperm for IVF/ICSI
Authors: Wald Moshe , Ross Lawrence S. , Prins Gail S. , Cieslak‐Janzen Jeanine , Wolf Georg , Niederberger Craig S.
Published: January 2006

ABSTRACT: We evaluated our experience to date with in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) after either cryopreserved sperm or sperm produced on the date of IVF/ICSI was used. We performed a retrospective statistical analysis of data derived from 188 women undergoing IVF/ICSI cycles using surgically retrieved sperm. A total of 318 IVF/ICSI treatment cycles with 3280 ova were performed using testicular sperm extraction (TESE, 304 cycles) or microsurgical epididymal sperm aspiration (MESA, 14 cycles). Sperm obtained at time of IVF/ICSI (fresh) or thawed cryopreserved sperm samples were used in 38 and 280 of the ICSI cycles, respectively. For IVF/ICSI cycles using both TESE and MESA sperm, the fertilization rate was 59.9% for cryopreserved sperm, and 53.6% when fresh sperm was used (χ2 P‐α < .02, Cramer's φ 0.04). The fertilization rate for the TESE group alone was 60.0% for cryopreserved sperm and 55.1% for fresh sperm (χ2 P‐α = .075). Cohen effect size was computed at 0.03; yielding for P‐β = .8, 6597 ova would be required to demonstrate similarity between fresh and cryopreserved sperm in the TESE group. To demonstrate superiority of cryopreserved sperm in this group at a P‐α significance level of .05, 7524 ova would be necessary. The pregnancy rate for the TESE group was 27.3% for cryopreserved sperm and 27% for fresh sperm. Further analysis of the pregnancy data in this group, using the methods described, yielded a χ2 P‐α and power of 0.971 (effect size calculated at 0.002). While our fertilization rates for cryopreserved sperm are greater in analyses of surgically derived sperm, based on the 7 years required to obtain data on 3280 ova, full numerical resolution of the issue of whether cryopreserved sperm is superior or similar will not be available until approximately 2010. However, we believe these results, along with the similarity shown in pregnancy rates achieved with both types of sperm, clearly indicate that cryopreserved sperm is not inferior to fresh sperm.
Clinical Use of Pentoxifylline for Activation of Immotile Testicular Sperm Before ICSI in Patients With Azoospermia
Authors: Kovačič Borut , Vlaisavljević Veljko , Reljič Milan
Published: January 2006

ABSTRACT: The testicular sperm from biopsy and frozen/thawed tissue are frequently immotile. The purpose of our retrospective study was to assess the effect of short exposure of testicular samples with only immotile sperm to pentoxifylline (PF)‐sperm motility stimulator. In 77 of 294 (26.2%) testicular sperm ablation/testicular sperm extraction‐intracytoplasmic sperm injection (TESA/TESE‐ICSI) cycles in patients with azoospermia, only immotile sperm were found in biopsies even after 2 hours of incubation of tissue in the medium. These 77 cycles were divided into 2 groups. In group 1 (cycles between 1999 and 2001; n = 30), ICSI was performed with untreated immotile sperm. In group 2 (cycles between 2002 and 2004; n = 47), immotile testicular sperm were treated for 20 minutes with pentoxifylline (PF) (1.76 mM) before ICSI. Both groups had the same proportion of ICSI cycles with fresh, frozen/thawed, and aspirated testicular sperm. The overall pregnancy rate of TESA/TESE‐ICSI did not vary during the study period. In 45 of 47 (95.7%) testicular samples with total immotility, the sperm started to move 20 minutes after PF treatment. The mean time required for ICSI was shortened in the PF group (30 minutes [minimum 10, maximum 90] vs 120 minutes [minimum 60, maximum 240]) due to easier identification of motile sperm. In comparison with the nontreated group, the PF group had a higher fertilization rate (66% vs 50.9%; P < .005) and mean number of embryos per cycle (4.7 ± 3.3 vs 2.7 ± 2.1; P < .01). The clinical pregnancy rate per cycle in PF and non‐PF groups was 38.3% and 26.7%, respectively. By using PF in cases of only immotile testicular sperm we can cause movement of testicular sperm, allow easier identification of vital sperm, shorten the procedure, improve fertilization rates, and increase the number of embryos.
Studies on Varicocele III: Ultrastructural Sperm Evaluation and 18, X and Y Aneuploidies
Authors: Baccetti Baccio M. , Bruni Emanuele , Capitani Serena , Collodel Giulia , Mancini Stefano , Piomboni Paola , Moretti Elena
Published: January 2006

ABSTRACT: The idea that varicocele plays a detrimental role in fertility is supported by the presence of a higher frequency of affected men among the infertile population than among men with normal semen parameters. In this research we examined ejaculates from a large group of selected men affected by varicocele by light and electron microscopy. The effect of varicocele on chromosome meiotic segregation was investigated by fluorescence in situ hybridization (FISH). The potential benefits of varicocelectomy on sperm quality were evaluated by analyzing sperm characteristics before and after surgical correction of varicocele. Transmission electron microscopy (TEM) analysis, elaborated previously, showed that the incidence of immaturity, apoptosis, and necrosis was higher in the varicocele group than in controls. FISH analysis performed on sperm nuclei from selected patients with varicocele showed that the mean frequencies of disomies and diploidies were generally out of the normal range, indicating a severe disturbance in meiotic segregation. Sperm characteristics evaluated before and after varicocele repair showed a general improvement. As a consequence, the varicocele seem to affect sperm morphology and function concomitantly with meiotic segregation derangement. In consideration of these data, we suggest that TEM and FISH analyses should be performed for all varicocele patients.
Male Infertility: No Evidence of Involvement of Androgen Receptor Gene Among Indian Men
Authors: Singh Rajender , Deepa Selvi R. , Madhavi Sakhamuri , Gupta Nalini J. , Chakravarty Baidyanath , Singh Lalji , Thangaraj Kumarasamy
Published: January 2006

ABSTRACT: Spermatogenesis is collaboratively controlled by testosterone and follicle stimulating hormone. Testosterone and its immediate metabolite dihydrotestosterone affect their roles through the androgen receptor (AR). Mutations in the AR gene have been shown to cause partial to complete androgen insensitivity or infertility in otherwise normal males. The dependence of germ cells upon Sertoli and Leydig cells for their differentiation into sperms and deletion studies of the AR gene in animal models indicate a direct or indirect role of the AR gene in spermatogenesis. Although a few studies worldwide have reported AR mutations in male infertility, no similar study has been conducted on Indian populations. Therefore, we undertook this study to look at the contribution of AR mutations in male infertility among Indian men. We have sequenced the complete coding region of the AR gene in a total of 399 infertile samples, comprising 277 azoospermic, 100 oligozoospermic, and 22 oligoteratozoospermic samples. A total of 100 healthy males with proven fertility and the same ethnicity as the experimental group served as controls. Sequence analysis revealed no mutation in any of these samples. Our study suggests that mutations in the AR gene are less likely to cause azoospermia and oligozoospermia; however, it was difficult to rule out its effect in oligoteratozoospermia, as the sample size was small.
Infertile Men With Varicocele Show a High Relative Proportion of Sperm Cells With Intense Nuclear Damage Level, Evidenced by the Sperm Chromatin Dispersion Test
Authors: Enciso María , Muriel Lourdes , Fernández José Luis , Goyanes Vicente , Segrelles Enrique , Marcos Mercedes , Montejo Juan Manuel , Ardoy Manolo , Pacheco Alberto , Gosálvez Jaime
Published: January 2006

ABSTRACT: The frequency of sperm cells with fragmented DNA was studied in a group of 18 infertile patients with varicocele and compared with those obtained in a group of 51 normozoospermic patients, 103 patients with abnormal standard semen parameters, and 22 fertile men. The spermatozoa were processed to discriminate different levels of DNA fragmentation using the Halosperm® kit, an improved Sperm Chromatin Dispersion (SCD) test. In this technique, after an acid incubation and subsequent lysis, those sperm cells without DNA fragmentation show big or medium‐sized halos of dispersion of DNA loops from the central nuclear core. Otherwise, those spermatozoa containing fragmented DNA either show a small halo, exhibit no halo with solid staining of the core, or show no halo and irregular or faint stain of the remaining core. The latter, that is, degraded type, corresponds to a much higher level of DNA‐nuclear damage. The varicocele patients showed 32.4% ± 22.3% of spermatozoa with fragmented DNA, significantly different from the group of fertile subjects (12.6% ± 5.0%). Nevertheless, this was not different from that of normozoospermic patients (31.3% ± 16.6%) (P = .83) and with abnormal semen parameters (36.6% ± 15.5%) (P = .31). No significant differences were found between the normozoospermic patients and the patients with abnormal semen parameters. Strikingly, the proportion of the degraded cells in the total of sperm cells with fragmented DNA was 1 out of 4.2 (23.9% ± 12.9%) in the case of varicocele patients, whereas it was 1 out of 8.2 to 9.7 in the normozoospermic patients (11.1% ± 9.9%) in the patients with abnormal sperm parameters (12.2% ± 8.3%) and in the fertile group (10.3% ± 7.2%). Thus, whereas no differences in the percentage of sperm cells with fragmented DNA were evident with respect to other infertile patients, individuals with varicocele exhibit a higher yield of sperm cells with the greatest nuclear DNA damage level in the population with fragmented DNA. This finding illustrates the value of assessing different patterns of DNA‐nuclear damage within each sperm cell and the particular ability of the Halosperm® kit to reveal them.
Reduced Seminal Parameters Associated With Environmental DDT Exposure andp,p′‐DDE Concentrations in Men in Chiapas, Mexico: A Cross‐Sectional Study
Authors: De Jager Christiaan , Farias Paulina , Barraza‐Villarreal Albino , Avila Mauricio Hernandez , Ayotte Pierre , Dewailly Eric , Dombrowski Christian , Rousseau François , Sanchez Vicente Diaz , Bailey Janice L.
Published: January 2006

ABSTRACT:In response to mounting concerns about the endocrine‐disrupting influence of environmental chemicals on human health, this epidemiological study was initiated to test the hypothesis that nonoccupational exposure to the estrogenic pesticide 1,1,1‐trichloro‐2,2‐bis(chlorodiphenyl)ethane (DDT) affects male reproductive parameters. One hundred and sixteen men aged 27 years (SD = 8.2) living in malaria endemic‐areas in Chiapas (Mexico), where DDT was sprayed until 2000, participated in a cross‐sectional study. Semen analyses were conducted according to World Health Organization methods and a quality control program was followed. DDT exposure was defined as the level of blood plasmap,p′‐dichlorodiphenyl dichloroethylene (DDE), the major metabolite of DDT. Thep,p′‐DDE concentration adjusted for total lipids was 100 times higher than that reported for nonexposed populations at 45 plus or minus 32 μg/g (mean ± SD). Crude regression analysis showed that several sperm motion parameters, including the percentage of motile sperm, decreased with higherp,p′‐DDE concentrations (β = −8.38;P= .05 for squared motility), and the percentage of sperm with morphological tail defects increased with higher plasmap,p′‐DDE concentration (β = 0.003;P= .017). Insufficient sperm chromatin condensation was observed in 46.6% of participants, and the most severe category of incomplete DNA condensation was also positively correlated withp,p′‐DDE concentration (r= .223;P= .044). Therefore, nonoccupational exposure to DDT, as assessed by plasmap,p′‐DDE concentrations, is associated with poorer semen parameters in men, indicating adverse effects on testicular function and/or the regulation of reproductive hormones. Previously, a causal role of environmental toxicants in human male infertility has been lacking because observed effects have been the result of unusually high exposures, either occupationally or as a result of industrial accidents, resulting in unprecedented controversy (reviewed by Cheek & McLachlan, Environmental hormones and the male reproductive system.J Androl. 1998;19:5). This is the first epidemiological study demonstrating effects after nonoccupational exposures to DDT. Based on these findings, the effect of DDT on male reproductive health should not be ignored.
Neoliberal and Public Health Effects of Failing to Adopt Osha's National Secondhand Tobacco Smoke Rule
Authors: Givel Michael
Published: January 2006

From the early 1980s to the present, neoliberal doctrine has called for government policies of privatization, funding cutbacks, and deregulation of public health and other domestic social programs in the belief that the market rather than the public sector can best organize and distribute crucial societal services. Proponents of a neoliberal and deregulatory mixed approach of command and control and self-regulation argue this approach provides the most adequate means to conduct regulation in the legalistic and adversarial U.S. regulatory process. In April 1994, the Occupational Safety and Health Administration issued a proposed rule to eliminate tobacco smoking in most workplace rooms, arguing secondhand tobacco smoke annually killed up to 13,700 nonsmokers. The tobacco industry purposely delayed public hearing procedures (later halted altogether by Congress and the president) primarily to advance unhindered private property rights and profits rather than submitting to a public command-and-control regulatory framework to reduce deaths due to secondhand tobacco smoke.
Argentina: No Lesson Learned
Authors: Iriart Celia , Waitzkin Howard
Published: January 2006

This article examines the political, ideological, social, and economic processes by which the Argentinean economy was transformed, the structural consequences, and the policies responsible for dismantling the welfare state. The health care system reform during the 1990s was an important component in accomplishing the last objective. Analyses of the policies adopted after the crisis of 2001 reveal that, despite the discourse against international financial institutions, President Nestor Kirchner, elected in 2002, followed the same approach by accepting and applying the second generation of health reforms recommended by the World Bank and the Inter-American Development Bank with additional pressure from the World Trade Organization and several free trade agreements. This “new reform” furthered business opportunities for multinational corporations while further shrinking the state administration's role in supplying health, education, and other social services to people who need them more than ever. Social movements have emerged that are developing alternative projects and showing that, when the base is solidarity, “another world is possible.”
Social Hazards on the Job: Workplace Abuse, Sexual Harassment, and Racial Discrimination—A Study of Black, Latino, and White Low-Income Women and Men Workers in the United States
Authors: Krieger Nancy , Waterman Pamela D. , Hartman Cathy , Bates Lisa M. , Stoddard Anne M. , Quinn Margaret M. , Sorensen Glorian , Barbeau Elizabeth M.
Published: January 2006

This study documents the prevalence of workplace abuse, sexual harassment at work, and lifetime experiences of racial discrimination among the United for Health cohort of 1,202 predominantly black, Latino, and white women and men low-income union workers in the Greater Boston area. Overall, 85 percent of the cohort reported exposure to at least one of these three social hazards; exposure to all three reached 20 to 30 percent among black women and women and men in racial/ethnic groups other than white, black, or Latino. Workplace abuse in the past year, reported by slightly more than half the workers, was most frequently reported by the white men (69%). Sexual harassment at work in the past year was reported by 26 percent of the women and 22 percent of the men, with values of 20 percent or more in all racial/ethnic-gender groups other than Latinas and white men. High exposure to racial discrimination was reported by 37 percent of the workers of color, compared with 10 percent of the white workers, with black workers reporting the greatest exposure (44%). Together, these findings imply that the lived— and combined—experiences of class, race, and gender inequities and their attendant assaults on human dignity are highly germane to analyses of workers' health.
A Short Latency between Radiation Exposure from Nuclear Plants and Cancer in Young Children
Authors: Mangano Joseph J.
Published: January 2006

Previous reports document a short latency of cancer onset in young children exposed to low doses of radioactivity. The standard mortality ratio (SMR) for cancer in children dying before age ten rose in the period 6–10 years after the Three Mile Island and Chernobyl accidents in populations most exposed to fallout. SMRs near most nuclear power plants were elevated 6–10 years after startup, particularly for leukemia. Cancer incidence in children under age ten living near New York and New Jersey nuclear plants increased 4–5 years after increases in average strontium-90 in baby teeth, and declined 4–5 years after Sr-90 averages dropped. The assumption that Sr-90 and childhood cancer are correlated is best supported for a supralinear dose-response, meaning the greatest per-dose risks are at the lowest doses. Findings document that the very young are especially susceptible to adverse effects of radiation exposure, even at relatively low doses.
One Step Forward, Two Steps Back: Worker Representation and Health and Safety in the United Kingdom
Authors: Walters David
Published: January 2006

There is now quite strong evidence for a set of preconditions that help determine the effectiveness of worker representation and consultation in improving health and safety outcomes. One of these preconditions is a regulatory framework that defines workers' rights to representation and employers' obligations to respond. Using the United Kingdom as its focus, this article explores developments at the national policy level. It shows how long-awaited legislative reforms to improve provisions for worker representation in health and safety have so far failed to materialize and, instead, government strategy has concentrated on promoting voluntary approaches. The author reviews the evidence of what makes worker representation in health and safety effective and suggests that, far from abandoning approaches to legislative reform, the U.K. agencies should be seeking to make improvements to the British provisions if they are to provide the necessary stimulus and support for worker representation in health and safety at work. Such improvements need to address long-standing weaknesses in existing provisions and their relevance to the changing world of work. The arguments presented here apply to the essential role of regulatory support for worker participation in all advanced market economies if it is to improve health and safety outcomes.
A Review of Data on the U.S. Health Sector: Summer 2005
Authors: Skala Nicholas , Hellander Ida
Published: January 2006

This report presents information on the state of the U.S. health sector in late summer 2005. It includes data on the uninsured and underinsured and their access to health care, on socioeconomic inequalities in health care, and on the rising costs of health insurance. It also presents information on the role of corporate money in health and health care, focusing on the pharmaceutical and hospital industries. The authors include an update on Medicare HMOs and the prescription drug bill, the results of some recent public opinion polls on health care, and some international comparisons of health systems. The article ends with recent data on health (medical) savings accounts and high-deductible insurance plans.
A Conceptual Model of Work and Health Disparities in the United States
Authors: Lipscomb Hester J. , Loomis Dana , McDonald Mary Anne , Argue Robin A. , Wing Steve
Published: January 2006

Recent research in medicine and public health highlights differences in health related to race, ethnicity, socioeconomic status, and gender. These inequalities, often labeled “disparities,” are pervasive and pertain to the major causes of morbidity, mortality, and lost life years. Often ignored in discussions of health disparities is the complex role of work, including not only occupational exposures and working conditions, but also benefits associated with work, effects of work on families and communities, and policies that determine where and how people work. The authors argue that work should be considered explicitly as a determinant of health disparities. Their conceptual model and empirical evidence, built on previous contributions, describe how work contributes to disparities in health on multiple levels. The examples focus on the United States, but many of the key conceptual features can also be applied to other countries. The model emphasizes behaviors and characteristics of institutions rather than individual workers. This approach avoids a focus on individual responsibility alone, which may lead to victim blaming and failure to emphasize policies and institutional factors that affect large populations and systematically create and maintain racial, gender, and socioeconomic disparities in health.
A Critique of Jeffrey D. Sachs's The End of Poverty
Authors: Henwood Doug
Published: January 2006

Jeffrey Sachs's The End of Poverty is a manifesto and how-to guide on ending extreme poverty around the world; it promotes the U.N. Millennium Development Goals. Sachs achieved fame with his policy package for the “stabilization” of Bolivia (which did nothing to relieve Bolivia's poverty), and became advisor to the Yeltsin government in Russia and to Poland, Slovenia, and Estonia as they began their transitions to capitalism (the last three mixed successes; Russia a thorough disaster). Sachs later became more prominent as a critic of development orthodoxy, and was economic advisor to the Jubilee 2000 movement. The End of Poverty is full of sharp critiques of Western imperialism, but his views on the rest of the development business are more conventional.
Can They Carry on Working? Later Retirement, Health, and Social Inequality in an Aging Population
Authors: Bellaby Paul
Published: January 2006

In debates on pensions and retirement age, little attention has been paid to the relation between increased effective retirement age and the health of the older population. This article focuses on Britain at a crucial point in the past, when the reconstruction that followed recession in the late 1970s and early 1980s used previously accumulated pension and redundancy funds to pay off workers and make labor markets “flexible.” Using secondary data analysis of surveys of the same nationally representative sample in 1984 and 1991, the author argues that, while early retirement and retirement at age 60 (women) and 65 (men) took many able-bodied people out of the labor force, every increase in retirement age would have faced diminishing returns. Moreover, unemployment and exit from the labor market were accompanied in most cases by a perceived decline in well-being. The findings suggest that retirement should be tapered, not abrupt. Finally, there was pronounced inequality in the aging process that would have led to a situation in which a uniform policy on later retirement deepened the disadvantage of those least able to fend for themselves. Accordingly, the present U.K. government should positively discriminate in favor of the disadvantaged at retirement by reinforcing the state pension.
Hybrid Molecular/Inorganic Semiconductor Transistors in Vertical Architectures
Authors: Meruvia M. S. , Hümmelgen I. A.
Published: January 2006

Inorganic semiconductor–metal–semiconductor transistors were developed more than 40 years ago. However, despite being potentially attractive for fast switching and sensor applications, they are difficult to produce and usually show low base transport factors, thereby limiting their applicability. Recent developments in hybrid organic/inorganic semiconductor–metal–semiconductor transistors, however, demonstrate that high‐gain transistors can be produced using simple technologies. Additionally, their fabrication is compatible with well‐established silicon electronics technology, which provides an enormous advantage. These devices, built in a vertical architecture, offer attractive new possibilities due to the large variety of available molecular semiconductors, opening the possibility of incorporating new functionalities in silicon‐based devices.
Hydrothermal Growth of Manganese Dioxide into Three‐Dimensional Hierarchical Nanoarchitectures
Authors: Ding Y.‐S. , Shen X.‐F. , Gomez S. , Luo H. , Aindow M. , Suib S. L.
Published: January 2006

Novel three‐dimensional (3D) hierarchical nanoarchitectures of ϵ‐MnO2 have been synthesized by a simple chemical route without the addition of any surfactants or organic templates. The self‐organized crystals consist of a major ϵ‐MnO2 dipyramidal single crystal axis and six secondary branches, which are arrays of single‐crystal ϵ‐MnO2 nanobelts. The growth directions of the nanobelts are perpendicular to the central dipyramidal axis, which shows sixfold symmetry. The shape of the ϵ‐MnO2 assembly can be controlled by the reaction temperature. The morphology of ϵ‐MnO2 changes from a six‐branched star‐like shape to a hexagonal dipyramidal morphology when the temperature is increased from 160 to 180 °C. A possible growth mechanism is proposed. The synthesized ϵ‐MnO2 shows both semiconducting and magnetic properties. These materials exhibit ferromagnetic behavior below 25 K and paramagnetic behavior above 25 K. The ϵ‐MnO2 system may have potential applications in areas such as fabrication of nanoscale spintronic materials, catalysis, and sensors.
Enhancement of External Quantum Efficiency of Red Phosphorescent Organic Light‐Emitting Devices with Facially Encumbered and Bulky PtII Porphyrin Complexes
Authors: Ikai M. , Ishikawa F. , Aratani N. , Osuka A. , Kawabata S. , Kajioka T. , Takeuchi H. , Fujikawa H. , Taga Y.
Published: January 2006

An enhancement in the external quantum efficiency (QE) of red phosphorescent organic light‐emitting devices (OLEDs) by using facially encumbered and bulky meso‐aryl substituted PtII porphyrin complexes is demonstrated. The maximum external QEs of phosphorescent OLEDs doped with the facially non‐encumbered PtII porphyrin complex 1 [5,15‐bis[4‐(4,4‐dimethyl‐2,6‐dioxacyclohexyl)phenyl]‐2,8,12,18‐tetrahexyl‐3,7,13,17‐tetramethylporphyrin platinum(II)], the facially encumbered PtII porphyrin complex 2 [5,15‐bis(2,6‐dimethoxyphenyl)‐2,8,12,18‐tetrahexyl‐3,7,13,17‐tetramethylporphyrinato platinum(II)], the PtII porphyrin complex 3 that bears bulkier 3,5‐di‐tert‐butylphenyl substituents [5,15‐bis(3,5‐di‐t‐butylphenyl)‐2,8,12,18‐tetrahexyl‐3,7,13,17‐tetramethylporphyrin platinum(II)], and the “doubly‐decamethylene‐strapped” PtII porphyrin complex 4 were 1, 4.2, 7.3, and 8.2 %, respectively. The trend of increasing QE values in the order of 1 < 2 < 3 < 4 may be related to facial encumbrance and steric bulkiness of meso‐aryl substituted PtII porphyrin complexes. Especially, in the case of the PtII porphyrin 4, it is considered that the “double straps” play an important role in restricting rotational freedom of the meso‐aryl substituents. The triplet excited‐state lifetimes for PtII porphyrins 1–4 in OLEDs at an injection current density of 0.55 mA cm–2 were 80, 103, 140, and 152 μs, respectively. We believe that the trend of increasing triplet lifetime in going from 1 to 4 is correlated with suppressing non‐radiative decay.
Highly Ordered Mesoporous Silicon Carbide Ceramics with Large Surface Areas and High Stability
Authors: Shi Y. F. , Meng Y. , Chen D. H. , Cheng S. J. , Chen P. , Yang H. F. , Wan Y. , Zhao D. Y.
Published: January 2006

Highly ordered mesoporous silicon carbide ceramics have been successfully synthesized with yields higher than 75 % via a one‐step nanocasting process using commercial polycarbosilane (PCS) as a precursor and mesoporous silica as hard templates. Mesoporous SiC nanowires in two‐dimensional (2D) hexagonal arrays (p6m) can be easily replicated from a mesoporous silica SBA‐15 template. Small‐angle X‐ray diffraction (XRD) patterns and transmission electron microscopy (TEM) images show that the SiC nanowires have long‐range regularity over large areas because of the interwire pillar connections. A three‐dimensional (3D) bicontinuous cubic mesoporous SiC structure (Ia3d) can be fabricated using mesoporous silica KIT‐6 as the mother template. The structure shows higher thermal stability than the 2D hexagonal mesoporous SiC, mostly because of the 3D network connections. The major constituent of the products is SiC, with 12 % excess carbon and 14 % oxygen measured by elemental analysis. The obtained mesoporous SiC ceramics are amorphous below 1200 °C and are mainly composed of randomly oriented β‐SiC crystallites after treatment at 1400 °C. N2‐sorption isotherms reveal that these ordered mesoporous SiC ceramics have high Brunauer–Emmett–Teller (BET) specific surface areas (up to 720 m2 g–1), large pore volumes (∼ 0.8 cm3 g–1), and narrow pore‐size distributions (mean values of 2.0–3.7 nm), even upon calcination at temperatures as high as 1400 °C. The rough surface and high order of the nanowire arrays result from the strong interconnections of the SiC products and are the main reasons for such high surface areas. XRD, N2‐sorption, and TEM measurements show that the mesoporous SiC ceramics have ultrahigh stability even after re‐treatment at 1400 °C under a N2 atmosphere. Compared with 2D hexagonal SiC nanowire arrays, 3D cubic mesoporous SiC shows superior thermal stability, as well as higher surface areas (590 m2 g–1) and larger pore volumes (∼ 0.71 cm3 g–1).
Self‐Assembled Shape‐Memory Fibers of Triblock Liquid‐Crystal Polymers
Authors: Ahir S. V. , Tajbakhsh A. R. , Terentjev E. M.
Published: January 2006

New thermoplastic liquid‐crystalline elastomers have been synthesized using the telechelic principle of microphase separation in triblock copolymers. The large central block is made of a main‐chain nematic polymer renowned for its large spontaneous elongation along the nematic director. The effective crosslinking is established by small terminal blocks formed of terphenyl moieties, which phase separate into semicrystalline micelles acting as multifunctional junction points of the network. The resulting transient network retains the director alignment and shows a significant shape‐memory effect, characteristic and exceeding that of covalently bonded nematic elastomers. Its plasticity at temperatures above the nematic–isotropic transition allows drawing thin well‐aligned fibers from the melt. The fibers have been characterized and their thermal actuator behavior—reversible contraction of heating and elongation on cooling—has been investigated.
Sporadic onset of erythermalgia: A gain‐of‐function mutation in Nav1.7
Authors: Han Chongyang , Rush Anthony M. , Dib‐Hajj Sulayman D. , Li Song , Xu Zhe , Wang Yun , Tyrrell Lynda , Wang Xiaoliang , Yang Yong , Waxman Stephen G.
Published: January 2006

Objective

Inherited erythermalgia (erythromelalgia) is an autosomal dominant disorder in which patients experience severe burning pain in the extremities, in response to mild thermal stimuli and exercise. Although mutations in sodium channel Nav1.7 have been shown to underlie erythermalgia in several multigeneration families with the disease that have been investigated to date, the molecular basis of erythermalgia in sporadic cases is enigmatic. We investigated the role of Nav1.7 in a sporadic case of erythermalgia in a Chinese family.

Methods

Genomic DNA from patients and their asymptomatic family members were sequenced to identify mutations in Nav1.7. Whole‐cell patch clamp analysis was used to characterize biophysical properties of wild‐type and mutant Nav1.7 channels in mammalian cells.

Results

A single amino acid substitution in the DIIS4‐S5 linker of Nav1.7 was present in two children whose parents were asymptomatic. The asymptomatic father was genetically mosaic for the mutation. This mutation produces a hyperpolarizing shift in channel activation and an increase in amplitude of the response to slow, small depolarizations.

Interpretation

Founder mutations in Nav1.7, which can confer hyperexcitability on peripheral sensory neurons, can underlie sporadic erythermalgia. Ann Neurol 2006
Sichtbare Wesen, deutbare Zeichen, Mittel der Konstruktion: zur Relevanz der Bilder in der Wissenschaft
Authors: Hampe Michael
Published: January 2006

Die philosophischen Voraussetzungen und Folgen bildgebender Verfahren in den Wissenschaften werden betrachtet. Rechnen und Abbilden, Verfahren, die ehemals in Konflikt zueinander gesehen wurden, sind heute ineinander überführbar. Es sieht so aus, als würden auch in Zukunft Bilder immer wichtiger in der Wissenschaft. Das sollte jedoch nicht zu neuen Illusionen führen, dass vermeintlich unmittelbare Einsichten in das Wesen der Dinge möglich seien.
Visual Essences, Readable Signs, Means of Construction: On the Relevance of Images in Science
Authors: Hampe Michael
Published: January 2006

Seeing is believing, but images in science are often based on mathematical and philosophical presuppositions. Computation and imaging, which once seemed to be in conflict, have become interconvertible. It seems that pictures will become more and more important in science. This should not lead to new illusions about supposedly direct insights into the essence of things.
Manipulation of the small intestine as a cause of the increased inflammatory response after open compared with laparoscopic surgery
Authors: Hiki N , Shimizu N , Yamaguchi H , Imamura K , Kami K , Kubota K , Kaminishi M
Published: January 2006

Background

Laparoscopic surgery of the gastrointestinal tract involves a reduced immune response compared with open surgery. The aim of this study was to assess manual handling of the gut in open procedures as the principal cause of the enhanced immune response.

Methods

Eighteen Landrace pigs underwent gastrectomy by three different methods: conventional open wound with bowel manipulation, laparoscopically assisted gastrectomy, and gastrectomy without manipulation using a combination of open wound and laparoscopic surgical devices. Local inflammatory changes were assessed by ascites formation, intestinal adhesion development and intestinal inflammatory gene expression. Associated systemic inflammatory changes were determined by measuring portal and systemic plasma endotoxin levels, plasma inflammatory cytokine levels, liver inflammatory gene expression and transaminase levels.

Results

Significantly more postoperative intra-abdominal fluid and adhesions were seen in the open group. The expression of inflammatory cytokines was significantly greater in the intestine and liver in the open group. Portal and systemic levels of endotoxin, inflammatory cytokines and transaminases were also higher.

Conclusion

Manual handling of organs during gastrectomy is an important contributor to the molecular and humoral inflammatory response to surgery, supporting the use of minimally invasive techniques in gastrointestinal surgery.
Progressive rise in gut hormone levels after Roux-en-Y gastric bypass suggests gut adaptation and explains altered satiety
Authors: Borg C M , le Roux C W , Ghatei M A , Bloom S R , Patel A G , Aylwin S J B
Published: January 2006

Background

Bariatric surgery is the most effective treatment for achieving long-term weight loss in morbidly obese patients. This study investigated prospective changes in gut hormones and metabolic indices after Roux-en-ϒ gastric bypass (RYGB).

Methods

Six patients were seen before, and at 1, 3 and 6 months after operation. Blood was collected after a 12-h fast and at regular intervals after a mixed 420-kcal meal. Hormonal responses were determined, and comparisons between basal levels and areas under the curve were made. Visual analogue scores were used to assess satiety, hunger and nausea.

Results

Mean body mass index decreased from 48·3 kg/m2 before surgery to 36·4 kg/m2 6 months after RYGB. This was accompanied by a decrease in fasting leptin (P < 0·001) and insulin (P = 0·021) levels. At 1, 3 and 6 months after operation, progressively increasing peptide YY (P < 0·001), enteroglucagon (P = 0·045) and glucagon-like peptide 1 (P = 0·042) responses were observed. There was no change in fasting ghrelin levels (P = 0·144). Postprandial satiety was significantly increased by 1 month after surgery and this was maintained until the end of the study (P < 0·001).

Conclusion

RYGB resulted in substantial weight loss with enhanced postprandial satiety, a sustained weight plateau, and proportionate reduction in fasting insulin and leptin levels. Lack of the expected increase in appetite and food intake as components of a counter-regulatory response may be explained by gut adaptation and the consequent graded rise in the levels of gut hormones that promote satiety.
Prognostic significance of glycoprotein pMQ1 in breast cancer
Authors: Fon L J , Lioe T F , Mulligan K A , Johnston P G , McCormick D , Spence R A J
Published: January 2006

Background

A novel glycoprotein, pMQ1, is positively correlated with increasing histological grade in malignant astrocytomas. Cerebral metastases from breast cancer have also been found to contain pMQ1-positive cells. This study aimed to determine the role of pMQ1 in primary breast cancer.

Methods

Breast cancer specimens were analysed for pMQ1 by immunohistochemistry. The expression of pMQ1 was correlated with conventional prognostic indicators. Kaplan–Meier analyses were performed to compare clinical outcome between pMQ1-positive and pMQ1-negative tumours.

Results

pMQ1 was expressed in most of the breast cancer specimens. The surrounding normal tissue margins and benign breast tissues always lacked pMQ1 expression. A significant positive correlation was observed between pMQ1 expression and histological grade, the presence of lymphovascular invasion and Nottingham Prognostic Index. Cancers that were pMQ1 positive were significantly more likely to develop a local recurrence.

Conclusion

pMQ1 appears to be a tumour-associated protein. The positive correlation of pMQ1 with histological grade, presence of lymphovascular invasion and Nottingham Prognostic Index suggests that it confers an adverse prognosis.