bluuebunny/crossref_metadata_2025 huggingface dataset:
Laboratory Testing for Lupus Anticoagulants: A Review of Issues Affecting Results
Authors: Tripodi Armando
Published: August 2007

Background: Lupus anticoagulants (LA) are a heterogeneous class of immunoglobulins. Persistent LA positivity is a risk factor for the occurrence and recurrence of venous/arterial thromboembolism and/or pregnancy morbidity and qualifies the patient for anticoagulation therapy. The laboratory diagnosis for LA that is used for crucial decision-making about the optimal duration of the therapy rests entirely on diagnostic criteria. These criteria are based on the prolongation of phospholipid-dependent tests not corrected upon mixing patient and normal plasmas, with confirmation provided by the evidence that the anticoagulant is directed against proteins bound to negatively charged phospholipids.

Aims: This article reviews issues related to the diagnosis of LA, including the effect of preanalytical variables, choice of tests, results interpretation of screening, mixing and confirmation procedures, patients to be investigated, and transmission of results. Unresolved issues and future direction for research on laboratory diagnosis are also discussed.

Methods: Search of PubMed with the key term “lupus anticoagulant” plus articles and unpublished data known to the author.

Results and Conclusions: The preanalytical variables (i.e., plasma preparation and storage before analysis) as well as the diagnostic steps to detect LA present potential problems that undermine the process of making a correct diagnosis. A truly specific test for LA detection is badly needed, but its development may require understanding of the mechanisms associated with the occurrence of clinical events. Until then, clinical laboratories should rely on the existing procedures, which must be applied with caution and awareness of the many issues that may affect their results.
Second-Trimester Reference Intervals for Thyroid Tests: The Role of Ethnicity
Authors: La’ulu Sonia L , Roberts William L
Published: August 2007

Background: Thyroid function changes during pregnancy, complicating the diagnosis of thyroid disorders. Maternal thyroid dysfunction has been associated with a variety of adverse outcomes. We evaluated thyroid function test results by ethnicity and week of gestation during the 2nd trimester of pregnancy.

Methods: We collected 3064 blood specimens in serum tubes from Asians (13%), blacks (22%), Hispanics (23%), and whites (42%). We measured thyroid-stimulating hormone (TSH), total and free thyroxine (TT4 and FT4), total and free triiodothyronine (TT3 and FT3), thyroglobulin autoantibodies (TgAb), and thyroid peroxidase autoantibodies (TPOAb) by use of an ARCHITECT i2000SR (Abbott Diagnostics). The TSH reference interval was calculated for samples negative for both TgAb and TPOAb and reference intervals for TT4, FT4, TT3, and FT3 in antibody-negative samples with normal TSH.

Results: Serum samples were positive for TgAb in 10.6%, 1.8%, 6.2%, 6.5%, and 5.9% of Asian, black, Hispanic, white, and combined groups, respectively. Samples were positive for TPOAb in 12.4%, 4.1%, 11.8%, 12.3%, and 10.4% of the same groups, respectively. The nonparametric reference intervals for all participants were 0.15–3.11 mIU/L (TSH), 9.3–15.2 pmol/L (0.72–1.18 ng/dL; FT4), 89.0–176.3 nmol/L (6.90–13.67 μg/dL; TT4), 3.82–5.96 pmol/L (2.48–3.87 pg/mL; FT3), and 1.82–3.68 nmol/L (118–239 ng/dL; TT3).

Conclusions: Blacks had lower prevalences of TgAb and TPOAb positivity and of increased serum TSH. The prevalence of TgAb and TPOAb positivity was highest in Asians. Whites had the highest prevalence of increased TSH. The lower and upper reference limits of TT3 were significantly lower for Asians. Reference intervals for women in the 2nd trimester were different from those of nonpregnant individuals.
Introduction to the Special Issue: Media and Ethnic Minorities in Europe
Authors: d'Haenens Leen , Ogan Christine
Published: August 2007

Across the countries of Europe and within the European Union, there seems to be no end to discussions of policies related to migrants – from the labor migrants who came to Europe more than 40 years ago to the continued requests from prospective migrants who want to immigrate for asylum and family formation. The discussions on what those policies should be, range from multiculturalism to integration and assimilation. Shifts in policies have occurred because of the slow economic and educational progress made by some migrants; by the post-9/11 changes in attitudes and behavior among some Muslim migrants, and by concerns over the increased size of the migrant population.
Use of old and new media by ethnic minority youth in Europe with a special emphasis on Switzerland
Authors: Bonfadelli Heinz , Bucher Priska , Piga Andrea
Published: August 2007

The first part of this article summarizes research carried out during the last decade in the field of media use of ethnic minorities throughout Europe. Guiding research questions, underlying paradigms, and empirical evidence will be critically discussed in a comparative way. In the second part, empirical data of a Swiss survey among 1,600 adolescents aged 12 to 17 with migrant and Swiss backgrounds are presented. The comparative study points at similarities and differences in access to and use of old and new media such as the Internet as well as with the link between media use and social integration or cultural identity. Special emphasis is given to ethnic versus social factors as underlying explanatory factors. The results of the Swiss study are placed in the context of European research evidence.
Types of Integration, Acculturation Strategies and Media Use of Young Turks in Germany
Authors: Trebbe Joachim
Published: August 2007

Although most Turks in Germany belong to the second or third generation of immigrants, they have retained the social, cultural, and religious identity of their country of origin. This article deals with this double identity of young Turks in Germany and their language-bound exposure to television, radio, press, and the Internet. Telephone survey data are presented regarding the integration and media use of Turks in Germany. The survey was carried out in 2006 on behalf of the public broadcasting station of North Rhine-Westphalia (Westdeutscher Rundfunk, WDR). The analyses identify and describe different types of integration of Turks and investigate the relationship between their level of integration and their demographic profile as well as their patterns of media use. Causal analysis was focused on the question how different strategies of acculturation influence the use of mass media.
Culture-specific features as determinants of news media use
Authors: Gezduci Hasibe , d'Haenens Leen
Published: August 2007

This article, which looks at exposure to and the use of host and home media by Turkish diaspora in Belgium, illustrates that media use is determined by cultural as well as socio-demographic features. By means of a quantitative survey among four hundred respondents of Turkish origin between the ages of eighteen and sixty, the use of host and home media (i. e., old and new) in general and news contents in particular were analyzed in relation to culture-specific features such as ethnic cultural position, religion, and command of language, alongside with socio-demographic features such as age, gender, education, years of residence and socio-economic status. Our investigation showed religion, ethnic-cultural position and command of the Turkish language to be the strongest determinants for home language news media use, while host language news media use was strongly determined by command of the Dutch or French language, length of residence and educational level. These findings, especially those pertaining to news use, bring nuance to a certain number of earlier findings with Turkish youngsters in the Netherlands and Flanders (12–19), whose media use was predominantly related to socio-demographics.
Comparative effect of ozone, chlorine dioxide, and hydrogen peroxide on lignin: Reactions affecting pulp colour in the final bleaching stage
Authors: Pipon Guillaume , Chirat Christine , Lachenal Dominique
Published: August 2007

Several lignin-like model compounds (vanillin, syringaldehyde, guaiacol, syringol, p-benzoquinone, naphthoquinone) and commercial softwood lignin were submitted to small charges of ozone, chlorine dioxide and hydrogen peroxide in aqueous solution under conditions simulating a final bleaching stage. In the case of ozone, the coloured quinone models were directly destroyed, whereas the phenolic models and lignin underwent a two-step decomposition mechanism: chromophores were formed at very low ozone charges, and then were destroyed with increasing ozone charge. Chlorine dioxide had hardly any effects on the quinone models, but formed coloured groups from the phenolic models and lignin. However, these were more intensely coloured and were only partially removed with higher ClO2 charges. As for hydrogen peroxide, the colour of lignin and naphthoquinone were directly removed, at least partially, but high H2O2 charges were necessary. Consequently, ozone seems to be the best reagent for final bleaching in which small chemical charges are applied. We suggest reaction mechanisms between ozone and the phenolic model compounds and p-benzoquinone that can explain the observations.
Effects of Information Source, Pedigree, and Reliability on Operator Interaction With Decision Support Systems
Authors: Madhavan Poornima , Wiegmann Douglas A.
Published: August 2007

Objective: Two experiments are described that examined operators' perceptions of decision aids. Background: Research has suggested certain biases against automation that influence human interaction with automation. We differentiated preconceived biases from post hoc biases and examined their effects on advice acceptance. Method: In Study 1 we examined operators' trust in and perceived reliability of humans versus automation of varying pedigree (expert vs. novice), based on written descriptions of these advisers prior to operators' interacting with these advisers. In Study 2 we examined participants' post hoc trust in, perceived reliability of, and dependence on these advisers after their objective experience of advisers' reliability (90% vs. 70%) in a luggage-screening task. Results: In Study 1 measures of perceived reliability indicated that automation was perceived as more reliable than humans across pedigrees. Measures of trust indicated that automated “novices” were trusted more than human “novices”; human “experts” were trusted more than automated “experts.” In Study 2, perceived reliability varied as a function of pedigree, whereas subjective trust was always higher for automation than for humans. Advice acceptance from novice automation was always higher than from novice humans. However, when advisers were 70% reliable, errors generated by expert automation led to a drop in compliance/ reliance on expert automation relative to expert humans. Conclusion: Preconceived expectations of automation influence the use of these aids in actual tasks. Application: The results provide a reference point for deriving indices of “optimal” user interaction with decision aids and for developing frameworks of trust in decision support systems.
Insertion Loads and Forearm Muscle Activity During Flexible Hose Insertion Tasks
Authors: Grieshaber D. Christian , Armstrong Thomas J.
Published: August 2007

Objective: To quantify the physical demands of hose insertion tasks in automotive assembly operations and how they are affected by method and the mechanical interference between the hose and the flange. Background: Insertion tasks were identified by workers as physically demanding and can often lead to fatigue or losses in production attributable to pain or injury. Methods: Six male and 6 female participants pushed a 25.4-mm flexible rubber hose onto a stationary flange during simulated insertions. Three insertion methods — rock, straight, and twist — were examined in the study. Muscle activity of the finger flexors was recorded to estimate grip effort during the simulated insertions. Results: The twist method (114.8 N) resulted in a 26% reduction in axial force compared with the straight method (155.7 N). Average muscle activity ranged from a low of 14% maximum voluntary contraction (MVC; men, straight method) to a high of 67% MVC (women, twist method). Hose resultant forces ranged from a low of 52.2 N to a high of 461.1 N for all participants. Men exerted 6% higher resultant forces with 37% less muscle activity than women. Conclusion: There are situations when the 26% reduction in the axial force attributable to twisting may be helpful during an insertion, despite the fact that forearm muscle activity was highest for both male and female participants during twisting insertions. Application: The results of this study can be applied to the future design of tasks that involve the joining of two parts such as a hose and flange.
Impact of Order and Load Knowledge on Trunk Kinematics During Repeated Lifting Tasks
Authors: Kotowski Susan E. , Davis Kermit G. , Shockley Kevin
Published: August 2007

Objective: To determine if lifting random unknown weights is more detrimental than lifting sequences of unknown weights and to investigate whether load knowledge impacts the effect of lifting random box weights. Background: Much research has investigated lifting under known load conditions, but few studies have investigated unknown loads, especially when presented in random order. There has been some documentation of alteration in trunk mechanics when there is an overestimation of the unknown load. Method: Ten men and 10 women performed three lifting tasks: random unknown, random known, and same weight. A lumbar motion monitor was used to collect kinematic data, and Borg's Rating of Perceived Exertion (RPE) and a task risk rating were also assessed. Results: Both presentation order and load knowledge impacted trunk kinematics during repeated lifting tasks. However, these differences were relatively low in magnitude. Furthermore, kinematic response and perceived risk and exertion for these conditions varied between genders. Conclusion: Lifting random unknown loads appears to alter kinematic responses, particularly for men. Women attempt to modify the effect of random unknown loads by changing the lifting style through alterations in upper limb motions (e.g., drag box toward them prior to lifting). However, a need remains for a more comprehensive biomechanical investigation (e.g., spine loading) into the effects of random unknown loads because many of the effect sizes were small. Application: Small kinematic adaptations resulting from tasks involving unknown and random loads may be mediated by the use of visual cues, order of presentation, or a change in lifting style.
The Effects of Visual Display Distance on Eye Accommodation, Head Posture, and Vision and Neck Symptoms
Authors: Rempel David , Willms Kirsten , Anshel Jeffrey , Jaschinski Wolfgang , Sheedy James
Published: August 2007

Objective: Determine the effects of display viewing distance on both the visual and musculoskeletal systems while the text height is held constant across viewing distances. Background: The distance from the eyes to a computer display may affect visual and neck comfort. If the angular size of the characters remains the same, it is recommended that the display be placed at a farther viewing distance (e.g., 70—100 cm). However, in common usage, the character sizes are not adjusted based on viewing distance. Method: Participants under the age of 35 years ( N = 24) performed visually demanding tasks using a computer display for 2 hr each at three viewing distances (mean: 52.4, 73.0, and 85.3 cm) while torso and head posture were tracked. At the end of each task, eye accommodation was measured and symptoms were recorded. Results: The near distance was associated with significantly less blurred vision, less dry or irritated eyes, less headache, and improved convergence recovery when compared with the middle and far distances. Participants moved their torsos and heads closer to the monitor at the far distance. Conclusion: If the computer screen character sizes are close to the limits of visual acuity, it is recommended that the computer monitor be positioned between the near (52 cm) and middle (73 cm) distance from the eyes. Application: The location of a computer display should take into account the size of the characters on the screen and the visual acuity of the user.
A Meta-Analysis of Performance Response Under Thermal Stressors
Authors: Hancock P.A. , Ross Jennifer M. , Szalma James L.
Published: August 2007

Objective: Quantify the effect of thermal stressors on human performance. Background: Most reviews of the effect of environmental stressors on human performance are qualitative. A quantitative review provides a stronger aid in advancing theory and practice. Method: Meta-analytic methods were applied to the available literature on thermal stressors and performance. A total of 291 references were collected. Forty-nine publications met the selection criteria, providing 528 effect sizes for analysis. Results: Analyses confirmed a substantial negative effect on performance associated with thermal stressors. The overall effect size for heat was comparable to that for cold. Cognitive performance was least affected by thermal stressors, whereas both psychomotor and perceptual task performance were degraded to a greater degree. Other variables were identified that moderated thermal effects. Conclusion: Results confirmed the importance of task type, exposure duration, and stressor intensity as key variables impacting how thermal conditions affect performance. Results were consistent with the theory that stress forces the individual to allocate attentional resources to appraise and cope with the threat, which reduces the capacity to process task-relevant information. This represents a maladaptive extension of the narrowing strategy, which acts to maintain stable levels of response when stress is first encountered. Application: These quantitative estimates can be used to design thermal tolerance limits for different task types. Although results indicate the necessity for further research on a variety of potentially influential factors such as acclimatization, the current summary provides effect size estimates that should be useful in respect to protecting individuals exposed to adverse thermal conditions.
Optical Information for Car Following: The Driving by Visual Angle (DVA) Model
Authors: Andersen George J. , Sauer Craig W.
Published: August 2007

Objective: The present study developed and tested a model of car following by human drivers. Background: Previous models of car following are based on 3-D parameters such as lead vehicle speed and distance information, which are not directly available to a driver. In the present paper we present the driving by visual angle (DVA) model, which is based on the visual information (visual angle and rate of change of visual angle) available to the driver. Method: Two experiments in a driving simulator examined car-following performance in response to speed variations of a lead vehicle defined by a sum of sine wave oscillations and ramp acceleration functions. In addition, the model was applied to six driving events using real world-driving data. Results: The model provided a good fit to car-following performance in the driving simulation studies as well as in real-world driving performance. A comparison with the advanced interactive microscopic simulator for urban and nonurban networks (AIMSUN) model, which is based on 3-D parameters, suggests that the DVA was more predictive of driver behavior in matching lead vehicle speed and distance headway. Conclusion: Car-following behavior can be modeled using only visual information to the driver and can produce performance more predictive of driver performance than models based on 3-D (speed or distance) information. Application: The DVA model has applications to several traffic safety issues, including automated driving systems and traffic flow models.
Depth of Focus and Visual Recognition of Imagery Presented on Simultaneously Viewed Displays: Implications for Head-Mounted Displays
Authors: Winterbottom Marc D. , Patterson Robert , Pierce Byron J. , Covas Christine M. , Winner Jennifer
Published: August 2007

Objective: We sought to determine the optimal focal distance for a semitransparent monocular head-mounted display (HMD) integrated with a flight simulator display and to investigate whether observers experienced visual discomfort or impaired target recognition when using an HMD set at the optimal distance. Background: When an observer wears a monocular HMD and views a simulator display, focal distances of both displays must be within the observers' depth of focus to prevent blurred imagery. Because focal distance can vary by as much as 0.5 m in U.S. Air Force multifaceted simulator displays, we determined whether a monocular HMD could be integrated with a simulator display without blurred imagery or discomfort. Method: Depth of focus and visual recognition were measured with a staircase procedure, and visual discomfort was measured with a questionnaire. Results: Depth of focus was 0.64 diopters in one condition tested, but it was affected by luminance level and display resolution. It was recommended that HMD focal distance equal the optical midpoint of the range of viewing distances encountered in the simulator. Moreover, wearing an HMD produced a decline in recognition performance for targets presented on the simulator display despite both displays being within observers' depth of focus and producing no visual discomfort. Conclusion: Monocular HMDs can be integrated with multifaceted simulator displays without blurred imagery or visual discomfort, provided that the correct focal distance is adopted. Application: For situations involving simultaneously viewed visual displays.
Motion Sickness, Console Video Games, and Head-Mounted Displays
Authors: Merhi Omar , Faugloire Elise , Flanagan Moira , Stoffregen Thomas A.
Published: August 2007

Objective: We evaluated the nauseogenic properties of commercial console video games (i.e., games that are sold to the public) when presented through a head-mounted display. Background: Anecdotal reports suggest that motion sickness may occur among players of contemporary commercial console video games. Methods: Participants played standard console video games using an Xbox game system. We varied the participants' posture (standing vs. sitting) and the game (two Xbox games). Participants played for up to 50 min and were asked to discontinue if they experienced any symptoms of motion sickness. Results: Sickness occurred in all conditions, but it was more common during standing. During seated play there were significant differences in head motion between sick and well participants before the onset of motion sickness. Conclusion: The results indicate that commercial console video game systems can induce motion sickness when presented via a head-mounted display and support the hypothesis that motion sickness is preceded by instability in the control of seated posture. Application: Potential applications of this research include changes in the design of console video games and recommendations for how such systems should be used.
Influence of Age and Proximity Warning Devices on Collision Avoidance in Simulated Driving
Authors: Kramer Arthur F. , Cassavaugh Nicholas , Horrey William J. , Becic Ensar , Mayhugh Jeffrey L.
Published: August 2007

Objective: We conducted a set of experiments to examine the utility of several different uni- and multimodal collision avoidance systems (CASs) on driving performance of young and older adult drivers in a high-fidelity simulator. Background: Although previous research has examined the efficacy of different CASs on collision avoidance, there has been a dearth of studies that have examined such devices in different driving situations with different populations of drivers. Method: Several different CAS warnings were examined in varying traffic and collision configurations both without (Experiment 1a) and with (Experiment 2) a distracting in-vehicle task. Results: Overall, collision avoidance performance for both potential forward and side object collisions was best for an auditory/visual CAS, which alerted drivers using both modalities. Interestingly, older drivers (60—82 years of age) benefited as much as younger drivers from the CAS, and sometimes they benefited more. Conclusion: These data suggest that CASs can be beneficial across a number of different driving scenarios, types of collisions, and driver populations. Application: These results have important implications for the design and implementation of CASs for different driver populations and driving conditions.
“Showing Roughness in a Beautiful Way”: Talk about Love, Coercion, and Rape in South African Youth Sexual Culture
Authors: Wood Kate , Lambert Helen , Jewkes Rachel
Published: August 2007

Sexual violence within as well as outside sexual relationships has far‐reaching public health and human rights implications and is a continuing focus of popular debate, media coverage, and research in postapartheid South Africa. Partly because it has been shown to affect individual vulnerability to HIV/AIDS, sexual violence has in recent years become framed as a global public health issue. International research efforts to document the scale of this personally and politically sensitive problem can encounter conceptual, definitional, and methodological difficulties that anthropology is well placed to assist in alleviating. This article offers an ethnographic exploration of the spectrum of practices relating to sexual coercion and rape among young people in a township in the former Transkei region of South Africa. Contextualizing meanings of sexual coercion within local youth sexual culture, the article considers two emic categories associated with sex that is “forced”: ukulala ngekani: “to sleep with by force” or ukunyanzela: “to force,” both usually used to describe episodes occurring within sexual partnerships; and ukudlwengula, used to describe rape by a nonpartner or stranger. The article discusses the semantic content of and differences between these two key categories, demonstrating that encounters described as “forced sex” encompass not only various forms of sexual coercion but also, particularly in the narratives of young men, instances of more consensual sex. Of importance, in turn, in defining an act as “rape” rather than as “forced sex” are the character of the relationship between the two parties and interlinked ideas relating to exchange and sexual entitlement, love, and the importance of “intention,” violation, and “deserving” victimhood.
The Meaning of the Present: Hope and Foreclosure in Narrations about People with Severe Brain Damage
Authors: Antelius Eleonor
Published: August 2007

In this article, I consider narratives told within a clinical setting. I argue that personnel in a day center for people with acquired brain damage are constantly involved in narrating about the disabled participants. The negotiation of who the participant is, and foremost will be, is in constant negotiation in regard to issues of hope. I further argue that hope is a meaning‐making process and, as such, it has been defined as crucially connected to time. Hope has been said to enable a connection between the present and the future, because action taken in the present could bring about (positive) change in the future. However, I show that hope, in relation to narratives told about people with severe disabilities that are considered “incurable,” must be understood within a realm of narrative foreclosure. Time seems to have lost the openness of its horizon for these people, and a narrative that tells of immediacy rather than chronology is created, resulting in hope being established within the present.
Tag STS in the AZF Region Associated With Azoospermia in a Tunisian Population
Authors: Hadjkacem‐Loukil Lobna , Ayadi Imen , Bahloul Ali , Ayadi Hammadi , Ammar‐Keskes Leila
Published: August 2007

ABSTRACT: The aim of this study was to determine the appropriate tag sequence tagged site (STS) associated with azoospermia. We evaluated the incidence of Y chromosome microdeletions in Tunisian infertile male patients by polymerase chain reaction using 14 STSs in the azoospermia factor (AZF) region of Yq11. A logistic regression analysis was performed to test the association of STSs with semen quality. Haploview version 3.11 was used to identify the possible blocks of deletion involving a minimum number of STSs and that can be used to tag the deletion block in future analysis. Using the 14 STSs, 48% infertile patients (102 of 210) had microdeletions of Y chromosome but, following the European Academy of Andrology guidelines, only 16% of patients had microdeletions. A statistically significant difference was found with some STSs for azoospermia and oligozoospermia. A candidate combinaison composed of 4 STSs (RBMY‐sy157‐sy84‐sy130) was associated with azoospermia in a Tunisian population. According to this study, this tag can be used in the screening of Y chromosome microdeletions before assisted reproduction treatment in a Tunisian population.
Ability of Abnormally‐Shaped Human Spermatozoa to Adhere to and Penetrate Zona‐Free Hamster Eggs: Correlation With Sperm Morphology and Postincubation Motility
Authors: Bronson Richard A. , Bronson Susan K. , Oula Lucila D.
Published: August 2007

ABSTRACT:A body of evidence indicates that morphologically abnormal human spermatozoa may exhibit impaired ability to fertilize. Yet teratospermia has widely varying etiologies, including associations with varicoceles, following fever, cigarette smoking, and exposure to polychlorinated biphenyls. Abnormalities of sperm shape in mice have also been shown to be associated with autosomal gene mutations. These varying causes of teratospermia could have different molecular consequences reflected in altered sperm function. We studied the ability of morphologically abnormal human sperm to penetrate zona‐free hamster eggs as a measure of their ability to undergo an acrosome reaction and gamete membrane fusion. Motile sperm from ejaculates containing 15% normal sperm or less, as judged by World Health Organization (1999) criteria, were recovered by ISolate density centrifugation and capacitated by overnight incubation. Zona‐free hamster eggs were inseminated with 1 × 106motile capacitated cells and scored for sperm penetration after 3 hours of coincubation. A significant trend was found between the percent of abnormal spermatozoa within the ejaculate and impaired egg‐penetrating ability, reflected in the percent of eggs penetrated, the number of penetrating sperm per egg, and the number of sperm adherent to the oolemma. Because only acrosome‐reacted human spermatozoa adhere to the oolemma, these results support the notion that abnormally shaped sperm may exhibit an impaired ability to undergo an acrosome reaction. A correlation was also noted between the loss of motility of sperm following overnight incubation and impairment of their ability to undergo gamete membrane fusion. These results confirm prior findings at the level of the zona pellucida that abnormally shaped sperm exhibit functional abnormalities. However, a wide variation was observed between men in the behavior of such sperm, including occasionally high rates of egg penetration. These observations suggest that assessment of morphology may be an unreliable measure, for the individual, of sperm fertilizing ability and emphasize that sperm function testing is an important part of the evaluation of teratospermia.
Calmodulin and CaMKII in the Sperm Principal Piece: Evidence for a Motility‐Related Calcium/Calmodulin Pathway
Authors: Schlingmann Karen , Michaut Marcela A. , McElwee John L. , Wolff Collin A. , Travis Alexander J. , Turner Regina M.
Published: August 2007

ABSTRACT: Both cyclic AMP (cAMP)/protein kinase A (PKA) and calcium (Ca2+) signaling pathways are known to be involved in the regulation of motility in mammalian sperm. Calmodulin (CaM) is a ubiquitous Ca2+ sensor that has been implicated in the acrosome reaction. In this report, we identify an insoluble pool of CaM in sperm and show that the protein, in addition to its presence in the acrosome, is found in the principal piece of the flagellum. These findings are consistent with, though not proof of, the presence of a pool of CaM in the fibrous sheath. The Ca2+/CaM‐dependent protein kinase IIβ (CaMKIIβ), which is a downstream target of Ca2+/CaM, similarly localizes to the principal piece. In addition, we confirm earlier reports that a CaM inhibitor decreases sperm motility. However, we find that this inhibition can be largely reversed by stimulation of PKA if substrates for oxidative respiration are present in the medium. Our results suggest that the Ca2+/CaM/CaMKII signaling pathway in the sperm principal piece is involved in regulating sperm motility, and that this pathway functions either in parallel with or upstream of the cAMP/PKA pathway.
Neutralization of Cytokine Activity at the Receptor Level Improves Sperm Motility in Men With Spinal Cord Injuries
Authors: Brackett Nancy L. , Cohen Daniel R. , Ibrahim Emad , Aballa Teodoro C. , Lynne Charles M.
Published: August 2007

ABSTRACT: Men with spinal cord injury (SCI) have a unique semen profile characterized by normal sperm concentrations but abnormally low sperm motility. Previous studies showed that elevated concentrations of cytokines in the seminal plasma of these men contribute to this condition. For example, when elevated concentrations of interlekin‐1β (IL‐1β), IL‐6, and tumor necrosis factor‐α (TNF‐α) were immunoneutralized in the semen of men with SCI, sperm motility improved. The present study investigated if these cytokines act on sperm cell receptors to inhibit sperm motility. Semen was collected from men with SCI and from healthy non‐SCI men. Sperm were separated from the seminal plasma by centrifugation. Eight identical aliquots of 5000 sperm suspended in 50 μL of seminal plasma were prepared for each subject. Agents were added to the aliquots in order to neutralize IL‐1β, IL‐6, and TNF‐α at the receptor level. In SCI subjects, sperm motility improved in each treatment group compared with the untreated group, but statistical significance was reached only when neutralizing agents to all 3 cytokines were added. Improvement was less pronounced in subjects with close to normal semen cytokine concentrations or close to normal pretreatment sperm motility. In control subjects, IL‐1β, IL‐6, and TNF‐α were within normal values, and addition of receptor blockers to semen had no effect on sperm motility. These data support the hypothesis that cytokines act at the level of the sperm receptor to inhibit sperm motility. These data further support the notion that inactivating semen cytokines leads to improved sperm motility in SCI men. Our goal is to develop this finding into a treatment for low sperm motility in men with SCI.
Female Sexual Dysfunction and Hormonal Status in Spinal Cord Injured (SCI) Patients
Authors: Lombardi Giuseppe , Mondaini Nicola , Macchiarella Angelo , Del Popolo Giulio
Published: August 2007

ABSTRACT: To investigate a possible correlation between sexual hormonal status and the presence of female sexual dysfunction (FSD) using the Female Sexual Function Index (FSFI) in females with spinal cord injuries (SCI), we selected 39 SCI fertile‐aged women. At visit 1, we assessed the presence of FSD using the FSFI, and all individuals were submitted to a blood hormone evaluation on the third day of their menstrual cycle. The levels of serum follicle‐stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), thyroid‐stimulating hormone (TSH), cortisol, dehydroepiandrosterone sulphate (DHEA‐S), androstenedione, 17[α]‐hydroxyprogesterone; total and free testosterone, 17β‐estradiol, inhibin, sex hormone‐binding globulin (SHBG), and thyroid hormones (fT3 and fT4) were checked. Progesterone was measured on the 20th to 21st day after the menstrual cycle. In patients with amenorrhea, we tested all the hormones using 1 random blood test. After a 3‐month period, the tests were repeated. Overall, 23/39 (58.9%) patients continued to manifest at least one sexual dysfunction. These patients reached a median score of 19.52. All but 6 patients (15.3%) consistently showed hormonal values within the normal range. Of the 6 patients with abnormal hormonal alterations, 5 showed at least one sexual dysfunction, 2 had low levels of total testosterone, 1 had a low level of free testosterone, 1 suffered from hypothyroidism, 1 presented with low levels of cortisol, and 1 showed hypoprogesterone. There was no significant correlation between abnormal hormonal status and the presence of a specific sexual dysfunction, as assessed with the FSFI.
Rab4A GTPase—Catenin Interactions Are Involved in Cell Junction Dynamics in the Testis
Authors: Mruk Dolores D. , Lau Ann S. N. , Sarkar Oli , Xia Weiliang
Published: August 2007

ABSTRACT: A plethora of evidence has recently accumulated to suggest that Rab guanosine triphosphates (GTPases) may have functions other than those originally proposed in vesicle formation, movement, docking, and fusion. Studies have shown, for example, that Rab proteins interact with actin filaments and microtubules, illustrating cross‐talk between intracellular transport and cytoskeletal dynamics. In this report, we show that Rab4A associates with adherens junction signaling proteins in the testis. By immunoprecipitation, Rab4A was found to interact with α‐ and β‐catenin as well as with actin, vimentin, α‐ and β‐tubulin, and protein kinase C (PKC)‐α and ‐ε. Additionally, administration of Adjudin to adult rats up‐regulated the Rab4A level, which coincided with the loss of spermatocytes, round and elongating/elongated spermatids from the seminiferous epithelium. More importantly, the ability of Rab4A to associate with α‐ and β‐catenin increased during Adjudin‐induced junction restructuring in the testis, illustrating that Rab4A‐catenin interactions are likely to be involved in the disassembly of Sertoli—germ cell contacts. Taken collectively, these results suggest that Rab4A participates in adherens junction dynamics.
Varicocele and Adolescents: Semen Quality After 2 Different Laparoscopic Procedures
Authors: Zampieri Nicola , Zuin Veronica , Corroppolo Michele , Chironi Christian , Cervellione Raimondo Maximillian , Camoglio Francesco Saverio
Published: August 2007

ABSTRACT: The aim of this prospective study was to assess long‐term functional results (spermiograms) in subjects who underwent laparoscopic varicocelectomy via either of 2 procedures (ligation or preservation of testicular artery). A total of 122 patients underwent laparoscopic varicocelectomy performed via either of the 2 different procedures: complete ligation of the spermatic vessels or preservation of the spermatic artery. After surgery when patients achieved 18 years, they were asked to undergo semen analysis. Spermiogram results were divided into 2 subgroups: “normal” and “abnormal.” We analyzed volume, sperm count per mL, percentage of motile spermatozoa, percentage of normal spermatozoa, and percentage of vitality for each group. Both groups showed the same results in terms of “normal” and “abnormal” spermiograms (World Health Organization criteria), but analysis showed higher sperm concentration per mL, sperm motility, volume, vitality, and rate of morphologically normal sperm for the group with arteries preserved and “normal” spermiograms (P < .01). Analysis of data from the spermiograms showed that preservation of the testicular artery was the best possible option in terms of semen quality. Therefore, we believe that surgical treatment of varicocele should be carried out using procedures involving artery preservation.
Microvillar Size and Espin Expression in Principal Cells of the Adult Rat Epididymis Are Regulated by Androgens
Authors: Primiani Nadia , Gregory Mary , Dufresne Julie , Smith Charles E. , Liu Ye Lauren , Bartles James R. , Cyr Daniel G. , Hermo Louis
Published: August 2007

ABSTRACT: Principal cells of the epididymis are the most prominent cell type and are noted for an apical cell surface studded with microvilli. The latter contain channel proteins that condition the microenvironment of epididymal lumen and promote sperm maturation; however, the regulation of the structure and integrity of microvilli is not well known. Espins are a family of proteins implicated in microvillar growth. The objectives of this study were to assess the regulation of espin in epididymal principal cells both in vitro and in vivo. Treatment of immortalized rat caput epididymal (RCE) cells with increasing doses of a homogenized testicular extract revealed a dose‐dependent increase in the size of microvilli. Reverse transcriptase—polymerase chain reaction (RT‐PCR) of adult rat epididymal RNA using espin‐specific primers indicated the presence of a band at about 290 base pairs (bp) in all regions. Western blot analysis using affinity‐purified espin antibody confirmed the presence of an approximately 110‐kDa band in the epididymis, corresponding to espin isoform 1. In adult rats, immunocytochemistry revealed espin expression over principal cells. In orchidectomized rats, espin expression was significantly reduced, whereas ligation of the efferent ducts resulted in a decrease of espin expression but not to the extent of orchidectomy. The fact that espin expression was restored to control levels in orchidectomized rats supplemented with high levels of testosterone indicated that its expression was dependent on androgens and not on other lumicrine factors derived from the testis. Taken together, these data indicate that espin is expressed in the epididymis and is regulated by androgens.
Isolation and Characterization of LNCaP Sublines Differing in Hormone Sensitivity
Authors: Iguchi Kazuhiro , Ishii Kenichiro , Nakano Toru , Otsuka Takashi , Usui Shigeyuki , Sugimura Yoshiki , Hirano Kazuyuki
Published: August 2007

ABSTRACT: Prostate cancer is a heterogeneous disease with varying degrees of androgen sensitivity. In this study, we performed a limiting dilution of human prostate LNCaP cells, and isolated two sublines, LNCaP‐E9 and LNCaP‐G4, with differential hormone‐sensitivity. Two LNCaP sublines were obtained by the limiting dilution method. The growth of E9 cells was decreased in the presence of androgens, while that of androgen‐treated G4 cells was biphasic. Although the androgen receptor expression level in E9 cells was similar to that seen in G4 cells, the expression of PSA mRNA and protein was significantly lower in the E9 cells. Moreover, the androgen‐based stimulation of PSA mRNA expression was less sensitive in E9 cells than G4 cells. Intracellular zinc level did not differ between E9 and G4 cells, but ZnT3 mRNA expression was significantly higher in the E9 cells. When the cells were grafted at the subrenal capsule, the number of CD31‐positive vessels with a lumen was approximately 2.5 times higher than that in G4 tumors. LNCaP‐E9 cells show lower androgen sensitivity than LNCaP‐G4 cells. E9 and G4 cells would be helpful for understanding the biology of hormone‐refractory prostate cancer.
7α‐Methyl‐19‐Nortestosterone (MENT) vs Testosterone in Combination With Etonogestrel Implants for Spermatogenic Suppression in Healthy Men
Authors: Walton Melanie J. , Kumar Narender , Baird David T. , Ludlow Helen , Anderson Richard A.
Published: August 2007

ABSTRACT: Testosterone with a progestogen can suppress spermatogenesis for contraception. The synthetic androgen 7α‐methyl‐19‐nortestosterone (MENT) may offer advantages because it is resistant to 5α‐reduction and is therefore less active at the prostate. This study aimed to investigate MENT implants in combination with etonogestrel on spermatogenesis, gonadotropins, and androgen‐dependent tissues in comparison with a testosterone/etonogestrel regimen. Healthy men (n = 29) were recruited and randomized to receive 2 etonogestrel implants with either 600‐mg testosterone pellets repeated every 12 weeks or 2 MENT implants for up to 48 weeks. Testosterone concentrations in the testosterone group remained in the normal range. Subjects with 2 MENT implants showed peak MENT levels at 4 weeks with testosterone concentrations of 2 nmol/L. Sperm concentrations fell rapidly to less than 1 × 106/mL at 12 weeks in 8 of 10 subjects in the MENT group and 13 of 16 subjects in the testosterone group with equally suppressed gonadotropins. Thereafter, suppression was not maintained in the MENT group, and 6 men noted loss of libido. Fourteen men completed 48 weeks of testosterone treatment, and all became azoospermic. Hemoglobin concentrations rose, and high density lipoprotein‐cholesterol (HDL‐C) fell in both groups. The MENT group showed a fall in prostate‐specific antigen with no change in bone mass. MENT with a progestogen can achieve rapid suppression of spermatogenesis similar to testosterone, but this promising result was not sustained due to a decline in MENT release from the implants. This dose of testosterone, compared with previous studies using a lower dose with a higher dose of etonogestrel, had nonreproductive side effects without any increase in spermatogenic suppression. These data indicate the importance of the doses of progestogen and testosterone for optimum spermatogenic suppression while minimizing side effects.
Cryosurvival and In Vitro Fertilizing Capacity Postthaw Is Improved When Boar Spermatozoa Are Frozen in the Presence of Seminal Plasma From Good Freezer Boars
Authors: Hernández Marta , Roca Jordi , Calvete Juan J. , Sanz Libia , Muiño‐Blanco Teresa , Cebrián‐Pérez José A. , Vázquez Juan M. , Martínez Emilio A.
Published: August 2007

ABSTRACT: The study evaluated the protective effect of seminal plasma (SP) added to freezing extender against cryopreservation injuries to boar spermatozoa. Pooled sperm‐rich fractions collected from 9 fertile boars were frozen in 0.5‐mL straws after being extended in a conventional freezing extender either alone or supplemented with 5% of SPs (SP1‐SP4) collected from the sperm‐rich fractions (diluted 1:1, vol/vol, in Beltsville Thawing Solution extender) from 4 boars (1–4) with known sperm cryosurvival (poor, moderate, and good sperm freezers). Cryopreservation injuries were assessed in terms of postthaw sperm motility (assessed by computer‐assisted sperm analysis), viability (plasma membrane and acrosome integrity assessed simultaneously by flow cytometry), membrane lipid peroxidation (malondialdehyde [MDA] production), and the ability of thawed spermatozoa to fertilize in vitro—matured homologous oocytes. The addition of SP from good sperm freezers (SP3 and SP4) improved (P < .01) the motility and viability of thawed spermatozoa without any influence on MDA production. Moreover, SP from good sperm freezers also increased (P < .05) the percentage of penetrated (SP3) and polyspermic oocytes (SP4) with respect to the control. Neither the total amount of SP proteins, protein profiles, nor antioxidant capacity of the different SPs were related to the various cryosurvival/fertilizing capacities of the processed spermatozoa.