bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of sexual dysfunction services in Bristol, UK
Authors: Crowley Tessa , Coulson Catherine , Cahill David
Published: May 2007

We present the results of a survey of providers of sexual dysfunction services in Bristol. Seventeen stakeholders were identified and were sent a questionnaire to establish the availability of the services to clients. We enquired about provision of time, number and frequency of sessions offered to clients by different service providers. Fourteen of the seventeen (80%) questionnaires were returned. The total number of new patients seen was given as 1956. The private sector saw 90 new patients per year and 1834 were seen in the National Health Service (NHS) clinics. Currently there are two levels of management available for people with sexual problems in Bristol and these are broadly divided into the private/charitable and the NHS. It is important that all sectors work together to provide an appropriate service for the local population. There is a clear need for more resources for service provision for the management of sexual dysfunction
Notes on the female condom: experiences in Brazil
Authors: Barbosa Regina Maria , Kalckmann Suzana , Berquó Elza , Stein Zena
Published: May 2007

A nationwide effort to introduce the female condom (FC) into public health services was undertaken in Brazil in 1998–99. To this end, the Ministry of Health sponsored a national research group of public health professionals, aided by local field workers and supervisors, to conduct a preparatory study at 20 sites in six cities. Clinic health workers were trained to conduct the study. Following an educational session, 2382 women volunteered to use the FC and to report their experiences at follow-up. Among those seen at 15 days, 1782 had used the FC at least once; among those seen at the 90-day follow-up, 1453 women had used it at least once, while 1296 of them liked it and wished to continue its use. Among these 1296 women, barrier use at last intercourse (either with a male or a female condom) was more than double at 90 days what it had been at baseline: 70% compared with 33%. Clinics providing active health-education activities achieved higher rates of follow-up and of FC acceptability.

These findings suggest that in Brazil, the introduction of the FC at public health centres could lead to high initial adoption rates and that continued use would be effective in encouraging safer sex. The level of health education and type of clinic are likely to influence the effectiveness of a future programme.
Association between active GB virus-C (hepatitis G) infection and HIV-1 disease in Uganda
Authors: Yirrell D L , Wright E , Shafer L A , Campbell E , Van der Paal L , Kaleebu P , Grosskurth H , Whitworth J A
Published: May 2007

Although not linked to a disease, GB virus-C viraemia has been associated with an improved prognosis in HIV-1-co-infected individuals. Most studies have been conducted on men (men who have sex with men or injection drug users) infected with HIV-1 subtype B, whereas here we report on both male and female subjects from rural Uganda, predominantly infected via the heterosexual route with HIV-1 subtypes A and D. In a longitudinal study of 272 participants, 47 were GBV-C positive and 181 negative, as determined by reverse transcription-polymerase chain reaction, in both of two plasma samples taken a median of 5.0 years apart. The remainder either acquired (25) or cleared (19) infection. Multilevel regression analyses and Cox survival analyses revealed that participants chronically infected with GBV-C had a slower decline in CD4+ T cells ( P<0.001) and increased survival time ( P=0.041) compared with GBV-C RNA-negative, HIV-positive adults. We show that the association between active GBV-C co-infection and improved survival of HIV-1-infected adults is not restricted to HIV subtype B, but is also observed in both males and females infected with HIV subtypes A and D.
A comparison of vanadate to a 2′–5′ linkage at the active site of a small ribozyme suggests a role for water in transition-state stabilization
Authors: Torelli Andrew T. , Krucinska Jolanta , Wedekind Joseph E.
Published: May 2007

The potential for water to participate in RNA catalyzed reactions has been the topic of several recent studies. Here, we report crystals of a minimal, hinged hairpin ribozyme in complex with the transition-state analog vanadate at 2.05 Å resolution. Waters are present in the active site and are discussed in light of existing views of catalytic strategies employed by the hairpin ribozyme. A second structure harboring a 2′,5′-phosphodiester linkage at the site of cleavage was also solved at 2.35 Å resolution and corroborates the assignment of active site waters in the structure containing vanadate. A comparison of the two structures reveals that the 2′,5′ structure adopts a conformation that resembles the reaction intermediate in terms of (1) the positioning of its nonbridging oxygens and (2) the covalent attachment of the 2′-O nucleophile with the scissile G+1 phosphorus. The 2′,5′-linked structure was then overlaid with scissile bonds of other small ribozymes including the glmS metabolite-sensing riboswitch and the hammerhead ribozyme, and suggests the potential of the 2′,5′ linkage to elicit a reaction-intermediate conformation without the need to form metalloenzyme complexes. The hairpin ribozyme structures presented here also suggest how water molecules bound at each of the nonbridging oxygens of G+1 may electrostatically stabilize the transition state in a manner that supplements nucleobase functional groups. Such coordination has not been reported for small ribozymes, but is consistent with the structures of protein enzymes. Overall, this work establishes significant parallels between the RNA and protein enzyme worlds.
Identification of mRNAs that continue to associate with polysomes during hypoxia
Authors: Thomas Jeff D. , Johannes Gregg J.
Published: May 2007

Tumors must adapt to the hypoxic environment in order to grow beyond a benign microscopic mass. In addition to transcriptional activation mediated by HIF-1α, hypoxia has also been reported to inhibit translation. The degree of translational inhibition is dependent on the duration as well as the severity of the hypoxic insult. Anoxia (<0.02% O2) seems to have a more rapid and dramatic effect on translation as compared to hypoxia. We show here that prolonged hypoxia dramatically and reversibly inhibits translation in PC-3 cells. We also found that mTOR is inactivated and eIF-2α is phosphorylated during hypoxic treatment but only the eIF-2α phosphorylation correlates with the translational repression. We further used polysome analysis and microarray technology to analyze the impact of this translational repression on gene expression. We found that 33 mRNAs were refractory to this translational repression and that there was no correlation between mRNA induction and the ability to recruit ribosomes during hypoxia. We also found that ribosomal protein encoding mRNAs are more sensitive to this translational repression as compared to the majority of mRNAs. Although other reports have analyzed the effect of translation inhibition on gene expression under anoxic conditions, we believe that this is the first report in hypoxic cells. Our results show that the translational repression that occurs during hypoxia does impact gene expression in the highly transformed prostate cancer cell line, PC-3.
Validation Sequence Optimization: A Theoretical Approach
Authors: Adomavicius Gediminas , Tuzhilin Alexander
Published: May 2007

The need to validate large amounts of data with the help of the domain expert arises naturally in many data-intensive applications, including data mining, data stream, and database-related applications. This paper presents a general validation approach that generalizes different expert-driven validation methods developed for specialized validation problems. In particular, we model the validation process as a sequence of validation operators, explore various properties of such sequences, and present theoretical results that provide for better understanding of the validation process. We also address the problem of selecting the best validation sequence among the class of equivalent sequence permutations. We demonstrate that this optimization problem is NP-hard and present two heuristic algorithms for improving validation sequences.
An Evolutionary Random Policy Search Algorithm for Solving Markov Decision Processes
Authors: Hu Jiaqiao , Fu Michael C. , Ramezani Vahid R. , Marcus Steven I.
Published: May 2007

This paper presents a new randomized search method called evolutionary random policy search (ERPS) for solving infinite-horizon discounted-cost Markov-decision-process (MDP) problems. The algorithm is particularly targeted at problems with large or uncountable action spaces. ERPS approaches a given MDP by iteratively dividing it into a sequence of smaller, random, sub-MDP problems based on information obtained from random sampling of the entire action space and local search. Each sub-MDP is then solved approximately by using a variant of the standard policy-improvement technique, where an elite policy is obtained. We show that the sequence of elite policies converges to an optimal policy with probability one. Some numerical studies are carried out to illustrate the algorithm and compare it with existing procedures.
A Survey and Experimental Comparison of Service-Level-Approximation Methods for NonstationaryM(t)/M/s(t)Queueing Systems with Exhaustive Discipline
Authors: Ingolfsson Armann , Akhmetshina Elvira , Budge Susan , Li Yongyue , Wu Xudong
Published: May 2007

We compare the performance of seven methods in computing or approximating service levels for nonstationary M(t)/M/s(t) queueing systems: an exact method (a Runge-Kutta ordinary-differential-equation solver), the randomization method, a closure (or surrogate-distribution) approximation, a direct infinite-server approximation, a modified-offered-load infinite-server approximation, an effective-arrival-rate approximation, and a lagged stationary approximation. We assume an exhaustive service discipline, where service in progress when a server is scheduled to leave is completed before the server leaves. We used all of the methods to solve the same set of 640 test problems. The randomization method was almost as accurate as the exact method and used about half the computational time. The closure approximation was less accurate, and usually slower, than the randomization method. The two infinite-server-based approximations, the effective-arrival-rate approximation, and the lagged stationary approximation were less accurate but had computation times that were far shorter and less problem-dependent than the other three methods.
Computational Assessment of Nested Benders and Augmented Lagrangian Decomposition for Mean-Variance Multistage Stochastic Problems
Authors: Parpas Panos , Rustem Berç
Published: May 2007

We consider decomposition approaches for the solution of multistage stochastic programs that appear in financial applications. In particular, we discuss the performance of two algorithms that we test on the mean-variance portfolio optimization problem. The first algorithm is based on a regularized version of Benders decomposition, and we discuss its extension to the quadratic case. The second algorithm is an augmented lagrangian method. Our results indicate that the algorithm based on regularized Benders decomposition is more efficient, which is in line with similar studies performed in the linear setting.
GRASP and Path Relinking for the Two-Dimensional Two-Stage Cutting-Stock Problem
Authors: Alvarez-Valdes Ramón , Martí Rafael , Tamarit Jose M. , Parajón Antonio
Published: May 2007

We develop a greedy randomized adaptive search procedure (GRASP) for the constrained two-dimensional two-stage cutting-stock problem. This is a special cutting problem in which the cut is performed in two phases. In the first phase, the stock rectangle is slit down its width into different vertical strips and in the second phase, each of these strips is processed to obtain the final pieces. We propose two different algorithms based on GRASP methodology. One is “piece-oriented” while the other is “strip-oriented.” Both procedures are fast and provide solutions of different structures to this cutting problem. We also propose a path-relinking algorithm, which operates on a set of elite solutions obtained with both GRASP methods, to search for improved outcomes. We perform extensive computational experiments with a wide range of instances, first to study the effect of changes in critical search parameters, and then to compare the efficiency of alternative solution procedures. The experiments establish the effectiveness of our procedure in relation to approaches previously identified as best, especially in large-scale instances.
Solution of Large Quadratic Knapsack Problems Through Aggressive Reduction
Authors: Pisinger W. David , Rasmussen Anders Bo , Sandvik Rune
Published: May 2007

The quadratic knapsack problem (QKP) calls for maximizing a quadratic objective function subject to a knapsack constraint. All coefficients are assumed to be nonnegative and all decision variables are binary. A new exact algorithm is presented, which makes use of aggressive reduction techniques to decrease the size of the instance to a manageable size. A cascade of upper bounds is used for the reduction, including an improved version of the Caprara-Pisinger-Toth bound based on upper planes and reformulation, and the Billionnet-Faye-Soutif bound based on Lagrangian decomposition. Generalized reduction techniques based on implicit enumeration are used to fix variables at their optimal values. In order to obtain lower bounds of high quality for the reduction, a core problem is solved, defined on a subset of variables. The core is chosen by merging numerous heuristic solutions found during the subgradient-optimization phase. The upper and lower bounding phases are repeated several times, each time improving the subgradient method used for finding the Lagrangian multipliers associated with the upper bounds. Having reduced the instance to a (hopefully) reasonable size, a branch and bound algorithm based on the Caprara-Pisinger-Toth framework is applied. Computational experiments are presented showing that several instances with up to 1,500 binary variables can be reduced to fewer than 100 variables. The remaining set of variables are easily handled through the exact branch and bound algorithm. In comparison to previous algorithms the framework does not only solve larger instances, but the algorithm also works well for instances with smaller densities of the profit matrix, which appear frequently when modeling various graph problems as quadratic knapsack problems.
Factors Influencing Variability in Compliance Rates and Clinical Outcomes Among Three Different Severe Sepsis Bundles
Authors: Fong Jeffrey J , Cecere Karen , Unterborn John , Garpestad Erik , Klee Mark , Devlin John W
Published: May 2007

BACKGROUND:

While 3 different quality indicator bundles are either approved (Voluntary Hospitals of America [VHA], Institute for Healthcare Improvement [IHI]) or proposed (Joint Commission on Accreditation of Healthcare Organizations [JCAHO]) to rate clinical practices in treatment of severe sepsis, it is suspected that differences in the quality indicators among these bundles may lead to discrepant benchmarking data.

OBJECTIVE:

To compare bundle compliance and patient factors associated with it among the IHI, JCAHO, and VHA severe sepsis bundles and explore possible reasons for any observed variability.

METHODS:

Using a retrospective, noninterventional design, we evaluated 50 adults (APACHE II score 25 ± 6, organ failure 2 ± 1, and shock 52%) with severe sepsis who were admitted consecutively to an intensive care unit at a 450 bed university-affiliated hospital.

RESULTS:

Few patients met 100% (IHI 6%, JCAHO 0%, VHA 6%) or 75% or greater (IHI 22%, JCAHO 6%, VHA 22%) of the quality indicators in each bundle. The number of patients who met 50% or more of the quality indicators varied significantly between JCAHO (28%) and both IHI (66%; p < 0.001) and VHA (60%; p < 0.001), but not between IHI and VHA (p = 0.53). Compliance with 50% or more of the quality indicators was more likely to occur when patients had shock (IHI, JCAHO, VHA), an APACHE II score greater than or equal to 25 (VHA), 2 or more organ failures (VHA), or survived hospitalization (IHI). We identified a number of factors that may help explain these differences.

CONCLUSIONS:

Differences among the IHI, JCAHO, and VHA severe sepsis bundles lead to variability in bundle compliance rates and the patient factors associated with the variability and may lead to confusion when benchmarking practices among institutions. Future efforts should focus on developing a single valid and reliable bundle that allows providers to improve the quality of sepsis care.

TRANSFONDO:

Tres diferentes organizaciones [“Voluntary Hospitals of America” (VHA), “Institute for Healthcare Improvement” (IHI), “Joint Commission on Accreditation of Healthcare Organizations” (JCAHO)] encargados con mejorar el cuidado médico en instituciones han desarrollado criterios de indicadores de calidad para el manejo apropiado de sepsis. Estas guiás de tratamiento han sido desarrollados con el propósito de proveer instituciones con un mecanismo para comparar la calidad de cuidado que ofrecen a sus pacientes que son admitidos con sepsis severa. Mientras que se han aprobado o propuesto tres diversos criterios de indicadores de calidad para evaluar las prácticas clínicas del manejo de sepsis severa, se sospecha que las diferencias entre estos indicadores pueden resultar en datos de comparación discrepantes.
Distribution of Lesions and Antigen of Highly Pathogenic Avian Influenza Virus A/Swan/Germany/R65/06 (H5N1) in Domestic Cats after Presumptive Infection by Wild Birds
Authors: Klopfleisch R. , Wolf P. U. , Uhl W. , Gerst S. , Harder T. , Starick E. , Vahlenkamp T. W. , Mettenleiter T. C. , Teifke J. P.
Published: May 2007

In early 2006, the highly pathogenic avian influenza virus (HPAIV) H5N1 of the Asian lineage caused the death of wild aquatic birds in Northern Germany. In the mainly affected areas, a trans-species transmission of HPAIV H5N1 to mammals occurred between birds and domestic cats and 1 Stone Marten ( Martes foina), respectively. Here, we report lesions and distribution of influenza virus antigen in 3 cats infected naturally with HPAIV H5N1 A/swan/Germany/R65/06. The hemagglutinin partial nucleotide sequences of the viruses were genetically closely related to a H5N1 HPAIV obtained from a dead Whooper Swan ( Cygnus cygnus) of the same area. At necropsy, within the patchy dark-red and consolidated lungs, there was granulomatous pneumonia caused by Aelurostrongylus sp. Histologically, the main findings associated with influenza in all cats were bronchointerstitial pneumonia and marked random hepatic necrosis. In addition, all animals displayed lymphoid necrosis in the spleen and Peyer's patches and necrosis of the adrenal cortex. Immunohistochemically, nucleoprotein of HPAIV was present intralesionally in the lungs, liver, adrenal glands, and lymphoid tissues. Oropharyngeal swabs were shown to be suited to detect HPAIV by quantitative real-time polymerase chain reaction (RT-PCR) in these cats, despite the paucity of influenza virus antigen in the upper respiratory tract by means of immunohistochemistry. The results show that outdoor cats in areas affected by HPAIV in wild birds are at risk for lethal infection. In conclusion, hepatic necrosis was, besides bronchointerstitial pneumonia, the primary lesion, suggesting that in naturally infected cats, damage to the liver plays an important role in the pathogenesis of H5N1 influenza.
Uveal Spindle Cell Tumor of Blue-Eyed Dogs: An Immunohistochemical Study
Authors: Zarfoss M. K. , Klauss G. , Newkirk K. , Kiupel M. , Jones Y. , Colitz C. M. H. , Dubielzig R. R.
Published: May 2007

Immunohistochemical techniques were used to investigate the origin of a spindle cell tumor in the anterior uveal tract of dogs and the influence of ultraviolet radiation on the development of this tumor. Thirteen tumors were identified from the 4,007 canine ocular samples examined at the Comparative Ocular Pathology Laboratory of Wisconsin between 1978 and 2005. Siberian Husky and Siberian Husky mix dogs were overrepresented (10/13 dogs, overall median age 10 years). Light microscopic evaluation (all dogs) and electron microscopy (2 dogs) were performed. Immunohistochemical staining included alpha-smooth muscle actin (SMA), vimentin, S-100, desmin, glial fibrillary acidic protein (GFAP), Melan A, microphthalmic transcription factor (MITF-1), protein gene product 9.5 (PGP 9.5), laminin, gadd45, p53, proliferating cell nuclear antigen (PCNA), anti-UVssDNA (antibody for detection of (6–4)-dipyrimidine photoproducts), and telomerase reverse transcriptase (TERT). All tumors occurred in the iris with or without ciliary body involvement and were composed of spindle cells arranged in fascicles and whorls (variable Antoni A and B behavior). All tumors were positive when immunostained for vimentin and S-100. Nine of 13 tumors exhibited GFAP immunopositivity. All tumors were negative for SMA, desmin, Melan A, and MITF-1. Tumors were variably positive for PGP 9.5, laminin, gadd45, p53, PCNA, anti-UVssDNA, and TERT. Electron microscopy revealed intermittent basal laminae between cells. These tumors are morphologically and immunohistochemically most consistent with schwannoma. The relationship between spindle cell tumors of the anterior uvea of dogs, altered neural crest, blue iris color, and ultraviolet radiation has not yet been fully elucidated.
Chondrodysplastic Calves in Northeast Victoria
Authors: McLaren P. J. , Cave J. G. , Parker E. M. , Slocombe R. F.
Published: May 2007

Outbreaks of chondrodysplasia in calves occur sporadically every 10–15 years, particularly following prolonged drought conditions, throughout Northeastern Victoria and the Southern Tablelands of New South Wales, Australia. An outbreak spanning 2 calving seasons (2003–2004) involving numerous losses through stillbirth, perinatal loss, and poor growth was investigated. Investigations of 4 representative cases are presented here with a definition of the gross and histopathologic defects and an overview of epidemiologic data gathered from affected farms. Calves showed variable disproportionate dwarfism without arthrogryposis. Long bones were shortened and showed axial rotation. Articular surfaces were distorted with misshapen weight-bearing surfaces associated with variable thickness of articular cartilage. Physes were distorted and variable in thickness with occasional foci of complete closure. The major histologic abnormality in the physes was disorderly development of the zones of cartilage hypertrophy, with reduced number and irregular arrangement of hypertrophic chondrocytes; similar less severe changes were present in the zones of cartilage proliferation. Histochemical staining of the cartilage matrix was variable in intensity, and there was evidence of abnormal resorption of cartilage matrix at the level of the primary spongiosa. Osteoid formation and subsequent bone remodelling seemed unaffected, and diaphyseal cortical bone appeared normal at the gross and light microscopic level. No infectious agents were identified, and other known causes for chondrodysplasia in calves were excluded. The most likely cause for the syndrome was considered to be congenital manganese deficiency. Further surveys of tissue and blood manganese levels from cows and calves with and without clinical signs from the region are planned.
Diagnoses and Clinical Outcomes Associated with Surgically Amputated Feline Digits Submitted to Multiple Veterinary Diagnostic Laboratories
Authors: Wobeser B. K. , Kidney B. A. , Powers B. E. , Withrow S. J. , Mayer M. N. , Spinato M. T. , Allen A. L.
Published: May 2007

Amputation is commonly performed in an attempt to both treat and diagnose conditions affecting the digits of cats. The records of multiple veterinary diagnostic laboratories were searched to identify submissions of amputated digits from cats. Eighty-five separate submissions were reviewed for diagnosis, age, sex, limb of origin, and digits affected; and the original submitting clinics were surveyed to determine clinical outcome. The Kaplan-Meier product-limit method was used to determine the disease-free interval and survival time. Neoplastic disease was identified in 63 of 85 submissions, with exclusively inflammatory lesions composing the other 22 cases. In 60 (95.2%) of the neoplastic cases, a malignant tumor was identified. Squamous cell carcinoma was the most commonly identified malignant tumor ( n = 15; 23.8%) and was associated with a median survival time of 73 days. Other diagnoses included fibrosarcoma ( n = 14; 22.2%); adenocarcinoma, likely metastases of a primary pulmonary neoplasm ( n = 13; 20.6%); osteosarcoma ( n = 5; 7.9%); mast cell tumor ( n = 4; 6.3%); hemangiosarcoma ( n = 5; 7.9%); malignant fibrous histiocytoma ( n = 2; 3.2%); giant cell tumor of bone ( n = 2; 3.2%); and hemangioma ( n = 2; 3.2%). Giant cell tumor of bone has not been previously described in the digits of cats. Various neoplasms can occur in the digits of cats, and submission of the amputated digit for histopathologic diagnosis is essential to determine the histogenesis and predict the clinical outcome.
Estrogen Receptors α and β and Progesterone Receptors in Normal Bovine Ovarian Follicles and Cystic Ovarian Disease
Authors: Salvetti N. R. , Acosta J. C. , Gimeno E. J. , Müller L. A. , Mazzini R. A. , Taboada A. F. , Ortega H. H.
Published: May 2007

The purpose of this study was to determine by immunohistochemistry the expression of estrogen and progesterone receptors in ovarian follicular structures from cows with cystic ovarian disease (COD) and to compare these with normal ovarian structures. Secondary, tertiary, atretic, and cystic follicles were evaluated. The follicular cysts of animals with COD presented a significantly higher expression of estrogen receptor α in all follicular layers than secondary, tertiary, and atretic follicles in both groups ( P < .05). The intensity of estrogen receptor β in the granulosa cell layer was stronger in tertiary than in secondary and atretic follicles in normal animals ( P < .05) and in growing and cystic follicles in animals with COD ( P < .05). Theca cells were scarcely stained in the 2 groups. Growing follicles and cysts from COD animals were less stained than tertiary follicles from normal animals ( P < .05). Differences did not exist between the 2 groups with regard to the progesterone receptor. Ovaries of animals with COD exhibited altered estrogen receptors expression compared with that in normal animals.
Kernicterus in an Adult Dog
Authors: Sangster C. R. , Stevenson C. K. , Kidney B. A. , Montgomery D. L. , Allen A. L.
Published: May 2007

A 7-year-old, spayed female, Wheaton terrier dog was icteric, lethargic, and anorexic with increased activity of hepatocellular and cholestatic liver enzymes and an extreme hyperbilirubinemia level of 609 μmol/L (reference interval: 1.0–4.0 μmol/L). Necropsy findings included profound icterus and red and yellow mottling of the liver. Yellow discoloration of the thalamic and subthalamic nuclei was detected on subgross examination of the formalin-fixed brain. Histologic examination of the brain revealed neuronal necrosis within the discolored nuclei, necrosis of Purkinje cells, and Alzheimer type II astrocytes in the cerebrocortical gray matter and in the nuclei, with gross discoloration. Histologic examination of the liver revealed extensive necrosis in a periacinar-to-bridging pattern and often extending to portal triads. A case of naturally occurring kernicterus in an adult dog secondary to extreme hyperbilirubinemia resulting from fulminant hepatic failure is reported. The few reports of this disease in domestic species involved neonates, namely 1 foal and 1 kitten.
Interstitial Cell Tumor and Sertoli Cell Tumor in the Testis of a Cat
Authors: Miller M. A. , Hartnett S. E. , Ramos-Vara J. A.
Published: May 2007

Testicular tumors are rarely reported in cats. We describe a case of interstitial cell tumor and Sertoli cell tumor in a cat that developed aggressive behavior and inappropriate urination 7 years after it was obtained from a shelter as an allegedly castrated 2 year old. At physical examination, the urine odor and the presence of penile papillae implied testosterone production. Testes were not palpable, but the left testis was found in the scrotum by surgical exploration and was mostly replaced by the 2 tumors. The interstitial cell tumor, but not the Sertoli cell tumor, was immunohistochemically positive for Melan-A, consistent with steroid production. Behavior improved after excision of the testis and penile papillae began to regress, but the cat was euthanatized 3 1/2 months after castration at the owner's request. Neither tumor had metastasized. The right testis was never found and was presumed to have been removed during the reported castration procedure.
Multiple Masses in a Horse's Tongue Resulting from an Atypical Perineurial Cell Proliferative Disorder
Authors: Vashisht K. , Rock R. W. , Summers B. A.
Published: May 2007

A 5-year-old National Show horse mare presented with a soft mass on the left dorsolateral aspect of the tongue. Over the next 2 years, the mare developed numerous, similar, coalescing masses that extended along the left dorsolateral aspect to the tip of the tongue. Microscopically, the bases for these masses were slender, fusiform, mesenchymal cells that formed compact whorls around myelinated and unmyelinated nerves. These cells were labeled by antibodies directed against vimentin but not by S-100. Ultrastructurally, multiple, concentrically arranged, long, slender cell processes, with discontinuous external laminae and many pinocytotic vesicles, helped to accurately phenotype the proliferative element. Whether this unusual perineurial cell proliferative disorder is neoplastic or not remained a matter of conjecture.
Individual differences in multiple dimensions of aggression: a univariate and multivariate genetic analysis
Authors: Vernon Philip A , McCarthy Julie M , Johnson Andrew M , Jang Kerry L , Harris Julie Aitken
Published: May 2007

Previous behaviour genetic studies of aggression have yielded inconsistent results: reported heritabilities for different types of aggressive behaviour ranging from 0 to 0.98. In the present study, 247 adult twin pairs (183 MZ pairs; 64 same-sex DZ pairs) were administered seven self-report questionnaires which yielded 18 measures of aggression. Univariate genetic analyses showed moderate to high heritabilities for 14 of these 18 measures and for a general aggression factor and three correlated aggression factors extracted from the measures. Multivariate genetic analyses showed sizeable genetic correlations between the different dimensions of aggression. Thus, individual differences in many types of aggressive behaviour are attributable to some extent to genetic factors and there is considerable overlap between the genes that operate on different types of aggressive behaviour.
Adolescent religiousness and its influence on substance use: preliminary findings from the Mid-Atlantic School Age Twin Study
Authors: D'Onofrio Brian M , Murrelle Lenn , Eaves Lindon J , McCullough Michael E , Landis Jessica L , Maes Hermine H
Published: May 2007

Research has consistently shown that religiousness is associated with lower levels of alcohol and drug use, but little is known about the nature of adolescent religiousness or the mechanisms through which it influences problem behavior in this age group. This paper presents preliminary results from the Mid-Atlantic School Age Twin Study, a prospective, population-based study of 6–18-year-old twins and their mothers. Factor analysis of a scale developed to characterize adolescent religiousness, the Religious Attitudes and Practices Inventory (RAPI), revealed three factors: theism, religious/spiritual practices, and peer religiousness. Twin correlations and univariate behavior-genetic models for these factors and a measure of belief that drug use is sinful reveal in 357 twin pairs that common environmental factors significantly influence these traits, but a minor influence of genetic factors could not be discounted. Correlations between the multiple factors of adolescent religiousness and substance use, comorbid problem behavior, mood disorders, and selected risk factors for substance involvement are also presented. Structural equation modeling illustrates that specific religious beliefs about the sinfulness of drugs and level of peer religiousness mediate the relationship between theistic beliefs and religious/spiritual practices on substance use. Limitations and future analyses are discussed.
Comparing the biological and cultural inheritance of personality and social attitudes in the Virginia 30 000 study of twins and their relatives
Authors: Eaves Lindon , Heath Andrew , Martin Nicholas , Maes Hermine , Neale Michael , Kendler Kenneth , Kirk Katherine , Corey Linda
Published: May 2007

Measures of four dimensions of personality (Psychoticism, Extraversion, Neuroticism, and Lie scores) and six aspects of social attitudes (to sex, taxation, militarism, politics, religion and a general conservatism scale) were obtained by mailed questionnaire from 29 691 US subjects including adult twins (n = 14 761) their parents (n = 2360), their spouses (n = 4391), siblings (n = 3184) and adult children (n = 4800). After correction for the average effects of age, sex and source of sample, familial correlations were computed for 80 distinct biological and social relationships. The data allow for the estimation of the additive and non-additive effects of genes, assortative mating, vertical cultural inheritance and other non-parental effects of the shared environment on differences in personality and social attitudes. The interaction of genetic and environmental effects with sex may also be analyzed. Model-fitting analyses show that personality and social attitude measures differ markedly in major features of family resemblance. Additive and dominant genetic effects contribute to differences in both personality and attitudes, but the effects of the family environment, including vertical cultural transmission from parent to child, are much more marked for social attitudes than for personality. There is substantial assortative mating for social attitudes and almost none for personality. The causes of family resemblance depend significantly on sex for almost every variable studied. These findings clarify and extend the more tentative findings derived from previous twin, family and adoption studies.
Etiology of covariation between reading and mathematics performance: a twin study
Authors: Knopik Valerie S , DeFries John C
Published: May 2007

The etiology of the observed relationship between reading and mathematics performance was examined by analyzing data from samples of same-sex twin pairs tested in the Colorado Learning Disabilities Research Center. Bivariate phenotypic and genetic structural equation models were fitted to data from 526 twin pairs selected for reading deficits (290 identical and 236 same-sex fraternal) and 355 control pairs (220 identical and 135 same-sex fraternal). Subtests of the Peabody Individual Achievement Test (PIAT; Reading Recognition, Reading Comprehension, and Spelling) were used as measures of reading performance, and scores from the Wechsler Intelligence Scale for Children-Revised (WISC-R) or Wechsler Adult Intelligence Scale-Revised (WAIS-R) Arithmetic subtest, the Wide Range Achievement Test Arithmetic subtest, and the PIAT Math subtest were used as indices for mathematics performance. The results of these confirmatory factor analyses indicate that genetic and environmental covariances between reading and math latent factors do not differ significantly for twin pairs in the proband and control groups. Estimates of heritability for reading performance in the proband and control samples were 0.81 and 0.69, respectively, and those for math performance were 0.88 and 0.67, respectively. Moreover, genetic influences accounted for 83% of the covariation between the reading and math factors in the proband group and for 58% of the covariation between these two latent variables in the control group; in contrast, shared environmental influences did not contribute significantly to the relationship between the reading and math latent factors nor to their independent variation.
Representativeness of a roster of volunteer North American twins with chronic disease
Authors: Mack Thomas M , Deapen Dennis , Hamilton Ann S
Published: May 2007

To identify large numbers of twins affected by chronic disease as potential subjects for studies of environmental and genetic chronic disease determinants, we advertised for affected twins over the period 1980–91 in newspapers across North America. Responses were received from 17 245 twin pairs in which cases of cancer or other chronic disease had occurred. To assess the representativeness of affected twins identified by advertising, we evaluated the pattern of reporting, compared the cases identified to the number of cases estimated to be prevalent among all North American twins, compared the cases to population-based singleton case series, compared the healthy co-twins to population-based samples of healthy persons, assessed the impact on ascertainment of opinions about disease causation, compared the pattern of prospective to retrospective ascertainment of disease in the originally unaffected co-twins of cases, and compared the results of the prospective ascertainment of disease in co-twins to comparable published estimates. Youth, gender, zygosity, education, and disease concordance were found to be overall determinants of ascertainment. Disease-discordant DZ twins appeared to be modestly underascertained. While somewhat better educated, both concordant and discordant pairs were judged to be reasonably representative of affected non-Hispanic white North American twin pairs of comparable status, ie of comparable age, sex, race, and zygosity. If interpreted with caution, the concordance patterns of such twins can be used to generate genetic hypotheses, but should not be the basis of definitive heritability analyses. We conclude that advertising offers a method of identifying pairs of twins that can serve as subjects for studies designed to identify disease determinants. Twin Research (2000) 3, 33–42.
Genetic and environmental influences on body fat distribution, fasting insulin levels and CVD: are the influences shared?
Authors: Nelson Tracy L , Vogler George P , Pedersen Nancy L , Hong Yuling , Miles Toni P
Published: May 2007

Central body fat distribution has been shown to be related to hyperinsulinemia, insulin resistance, hypertriglyceridemia, and atherosclerosis to a greater degree than general obesity. There are known to be both genetic and environmental effects on all components of this clustering. Whether these genetic effects are due to one set of genes in common to the components or whether genetic influences on insulin resistance and/or general/abdominal fatness ‘turn on’ other genes that affect other components of the syndrome is not clear. We analyzed data from the Swedish Adoption/Twin Study of Aging (60% female; monozygotic = 116, dizygotic = 202; average age 65 years) to determine whether there were genetic and/or environmental factors shared among general body fat distribution, abdominal body fat distribution, fasting insulin levels and cardiovascular disease. We found additive genetic effects in males to be significantly different from those in females with genetic effects accounting for variance in waist–hip ratio (males = 28%; females = 49%), body mass index (males = 58%; females = 73%), fasting insulin levels (FI) (males = 27%; females = 49%), and cardiovascular disease (CVD) (males = 18%; females = 37%). There were also shared genetic and environmental effects among all the variables except CVD, but a majority of the genetic variance for these measures was trait specific. Twin Research (2000) 3, 43–50.
Placenta of discordant twins: lack of change in histochemically detectable enzyme activities
Authors: Matsubara S , Minakami H , Sato I
Published: May 2007

We localised three important enzymes histochemically in placental trophoblasts from women who gave birth to dichorionic discordant twins, in which the co-twin was affected by foetal growth restriction (FGR). The enzymes studied were adenosine diphosphate-degrading enzyme (ADPdegrading enzyme, plasma membrane enzyme), cytochrome c oxidase (mitochondrial enzyme), and glucose-6-phosphatase (endoplasmic reticular enzyme). We compared these enzyme activities and their distribution patterns among placentas of the smaller (FGR) co-twin, larger co-twin, preeclamptic singleton with FGR, and normal singletons with birth weight of appropriate for their gestational ages. In FGR co-twin placentas, the intensity and localisation pattern of these three enzymes did not differ from those seen in the larger co-twin and normal singleton placentas. Decreased ADP-degrading activity and cytochrome c oxidase negative mitochondria, which were characteristic features of pre-eclamptic trophoblasts, were not observed in FGR co-twin placentas. These observations indicated that, in the FGR co-twin, enzyme-histochemically detectable trophoblastic cell dysfunction may be absent, or if present, less prominent, compared with preeclamptic FGR. We previously reported that placental trophoblasts from singleton idiopathic FGR also showed no reduction in these enzyme activities. In mechanism and pathophysiology, FGR in dichorionic discordant twins may be quite different from pre-eclamptic FGR, but somewhat resembles idiopathic FGR, though all three disorders lead to placental insufficiency, resulting in limited foetal growth. Twin Research (2000) 3, 123–128.
Infant zygosity can be assigned by parental report questionnaire data
Authors: Price Thomas S , Freeman Bernard , Craig Ian , Petrill Stephen A , Ebersole Lorna , Plomin Robert
Published: May 2007

A parental report questionnaire posted to a population sample of 18-month-old twins correctly assigned zygosity in 95%of cases when validated against zygosity determined by identity of polymorphic DNA markers. The questionnaire was as accurate when readministered at 3 years of age, with 96% of children being assigned the same zygosity on both occasions. The results validate the use of parental report questionnaire data to determine zygosity in infancy. Twin Research (2000) 3, 129–133.
Assisted reproductive technologies and monozygous twins: implications for future study and clinical practice
Authors: Sills E Scott , Tucker Michael J , Palermo Gianpiero D
Published: May 2007

That the zona pellucida (ZP) plays a prominent role in the physiology of some human twinning is an attractive, albeit incompletely proven, medical hypothesis. Indeed, an association has been proposed between manipulation of the ZP and/or native ZP microarchitecture and monozygotic (MZ) twins. Ovulation induction also has been theoretically linked to in vivo ZP alterations facilitating MZ twin development. In vitro fertilization (IVF) relies on necessary (and, in some cases extended) embryo culture techniques potentially creating subtle ZP changes and subsequent MZ twinning. With growing experience in the assisted reproductive technologies and particularly IVF, some preliminary reports have noted an increased frequency of MZ twins after procedures that artificially breach the ZP (i.e., intracytoplasmic sperm injection [ICSI], or ‘assisted hatching’). Such ZP manipulations ostensibly enhance oocyte fertilization or facilitate blastocyst hatching, thus improving pregnancy rates for couples undergoing fertility treatment. Evidence exists both to challenge and support the connection between these phenomena and MZ twins. This report outlines the fundamental embryological processes believed responsible for these conflicting observations; the current literature on the subject of human ZP micro-manipulation and MZ twins is also discussed. Twin Research (2000) 3, 217–223.
Genetics of testosterone and the aggression-hostility-anger (AHA) syndrome: a study of middle-aged male twins
Authors: Sluyter F , Keijser JN , Boomsma DI , van Doornen LJP , van den Oord EJCG , Snieder H
Published: May 2007

The aim of this study was to determine the genetic contribution to the variation in testosterone and the aggression-hostility-anger (AHA) syndrome in middle-aged twins. Moreover, the relation between testosterone and this syndrome, and possible common genetic mechanisms were investigated. Towards this end, blood samples were collected at two time points; the AHA syndrome was measured using three questionnaires: the Buss-Durkee Hostility Inventory with seven subscales, the Jenkins Activity Survey and the Spielberger State-Trait Anger Scale. The results showed substantial heritabilities for testosterone (approximately 60%) and moderate to fair heritabilities for the nine measures of the AHA syndrome (23–53%). The best fitting model for testosterone at two time points included a small age component and additive genetic and unique environmental factors, while a multivariate analysis of the nine AHA subscales resulted in an independent pathway model with two common additive genetic and two common unique environmental factors. No correlation between the common genetic factor influencing testosterone and the AHA subscales was found. We did, however, detect a negative correlation between the common environmental factor underlying testosterone and both common environmental factors influencing the nine AHA subscales, which may reflect a tendency for testosterone levels to rise and hostility to drop (or vice versa) after repeatedly experiencing success (or failure). Twin Research (2000) 3, 266–276.
A population-based study of personality in 34 000 sib-pairs
Authors: Martin Neilson , Goodwin Guy , Fairburn Christopher , Wilson Rob , Allison David , Cardon Lon R , Flint Jonathan
Published: May 2007

Several theoretical studies have suggested that large samples of randomly ascertained siblings can be efficiently used to ascertain phenotypically extreme individuals and increase power to detect genetic linkage. Phenotypes that can be reliably measured by questionnaire are of obvious utility for such selection strategies, as large numbers of individuals can be contacted without laborious individual interview. As the first step in developing a large randomly-ascertained family cohort in southwest England, a sample of 88 000 individuals, including more than 34 000 sibling pairs in 20 000 sibships, was administered the Eysenck Personality Questionnaire (EPQ) by commercial mailing. The sample age ranges were 20–67 years and comprised 59% males and 41% females. Descriptive properties of the EPQ scales are similar to those reported from other large family cohorts. Test–retest correlations on 1681 probands in the sample are substantial for the N-scale (r = 0.93), but somewhat more modest for the other scales (range r = 0.70–0.88). Phenotypic and sibling correlations correspond quite closely to those of twin studies. Twin Research (2000) 3, 310–315.