Search for intracranial aneurysm susceptibility gene(s) using Finnish families

Background

Cerebrovascular disease is the third leading cause of death in the United States, and about one-fourth of cerebrovascular deaths are attributed to ruptured intracranial aneurysms (IA). Epidemiological evidence suggests that IAs cluster in families, and are therefore probably genetic. Identification of individuals at risk for developing IAs by genetic tests will allow concentration of diagnostic imaging on high-risk individuals. We used model-free linkage analysis based on allele sharing with a two-stage design for a genome-wide scan to identify chromosomal regions that may harbor IA loci.

Methods

We previously estimated sibling relative risk in the Finnish population at between 9 and 16, and proceeded with a genome-wide scan for loci predisposing to IA. In 85 Finnish families with two or more affected members, 48 affected sibling pairs (ASPs) were available for our genetic study. Power calculations indicated that 48 ASPs were adequate to identify chromosomal regions likely to harbor predisposing genes and that a liberal stage I lod score threshold of 0.8 provided a reasonable balance between detection of false positive regions and failure to detect real loci with moderate effect.

Results

Seven chromosomal regions exceeded the stage I lod score threshold of 0.8 and five exceeded 1.0. The most significant region, on chromosome 19q, had a maximum multipoint lod score (MLS) of 2.6.

Conclusions

Our study provides evidence for the locations of genes predisposing to IA. Further studies are necessary to elucidate the genes and their role in the pathophysiology of IA, and to design genetic tests.     

Oestrogen and progesterone do not regulate the expression of retinoic acid receptors and retinoid 'X' receptors in human endometrial stromal cells in vitro

Elucidation of the gene structure for retinoic acid receptor-(RAR-) has suggested a potential role for oestrogen in regulatingthe expression of RAR-. We have previously shown that all threeRAR types are expressed in human endometrial stromal cells invitro and that RAR- expression is induced in response to retinoicacid. The aim of this study was to ask whether oestradiol andprogesterone could play a part in regulating the expressionof RARs in human endometrial stromal cells and to establishthe patterns of expression of a related group of nuclear retinoidreceptors, retinoid ‘X’ receptors (RXRs) and theirpotential for regulation by steroid hormones. The RAR expressionpatterns of endometrial stromal cells, grown in steroid-freemedium, did not change in response to the presence of steroidhormones. Furthermore, the retinoic acid-mediated inductionof RAR- was not affected by oestradiol or progesterone, andwas dependent on the continued presence of retinoic acid. Ofthe three RXR types, only RXR- was detectably expressed in stromalcells in vitro and the expression of RXR- did not change inresponse to steroid hormones or retinoic acid. These data indicatethat oestradiol and progesterone are not important in the regulationof RAR and RXR expression in human endometrial stromal cells.     

Integrating complementary and alternative medicine instruction into health professions education: organizational and instructional strategies.

A few years ago, the National Institutes of Health National Center for Complementary and Alternative Medicine funded a program called the Complementary and Alternative Medicine (CAM) Education Project. Grantees were 14 medical and nursing schools and the American Medical Student Association, which funded six additional medical schools. Grants were awarded in cohorts of five per year in 2000, 2001, and 2002-2003.The R25 grant recipients identified several major themes as crucial to the success of integrating CAM into health professions curricula. The rationale for integrating CAM curricula was in part to enable future health professionals to provide informed advice as patients dramatically increase the use of CAM. Success of new CAM education programs relied on leadership, including top-down support from institutions' highest administrators. Formal and informal engagement of key faculty and opinion leaders raised awareness, interest, and participation in programs. A range of faculty development efforts increased CAM-teaching capacity. The most effective strategies for integration addressed a key curriculum need and used some form of evidence-based practice framework. Most programs used a combination of instructional delivery strategies, including experiential components and online resources, to address the needs of learners while promoting a high level of ongoing interest in CAM topics. Institutions noted several benefits, including increased faculty development activities, the creation of new programs, and increased cross- and inter-university collaborations. Common challenges included the need for qualified faculty, crowded and changing curricula, a lack of defined best practices in CAM, and post-grant sustainability of programs.     

The diagnosis of male infertility--prospective time-specific study of conception rates related to seminal analysis and post-coital sperm--mucus penetration and survival in otherwise unexplained infertility

Infertile women without any inherent female infertility factorsand able to secrete normal cervical mucus were studied prospectivelyin relation to post-coital sperm—mucus penetration (PCT)and their partner's seminal analysis, excluding men with azoospermia.Time-specific cumulative conception rates calculated as forlife-table analysis were related to each measured seminal variableon routine analysis of 2–3 samples (volume, density, proportionwith progressive motility, and proportion with normal morphology);to various derivatives from combinations of these variables;to seminal findings after vital staining; and to the PCT results.The best seminal predictor of fertility was the motile normalsperm density (MNSD), the 18 month conception rates being 57.4%+ 4.6 (SE) and 30.2% + 5.9 (ratio 1.9, P < 0.001) above andbelow a derived threshold value of 4 x 10⁶/ml. The PCT led torates of 55.6% ± 4.3 and 14.9% ± 5.1 (ratio 3.73,P < 0.001) for positive and negative results, respectively.The PCT also gave rise to a significantly distinct intermediatepoor-psitive sub-group (conception rate 30.6% ± 9.0).Seminal analysis (the MNSD) did not affect the conception rateassociated with a positive PCT but helped to discriminate furtherwith a negative PCT (conception rates 22.5% ± 8.7 withan MNSD above 4 x 10⁶/ml versus 5.6% ± 4.8 below, P <0.05). The PCT was the single best predictor of fertility butseminal analysis (the MNSD) was of additional value after anegative PCT.     

Miscarriage rates following in-vitro fertilization are increased in women with polycystic ovaries and reduced by pituitary desensitization with buserelin

To assess the risk of miscarriage after in-vitro fertilization(IVF) with respect to age, cause of infertility, ovarian morphologyand treatment regimen, a retrospective analysis was performedof the first 1060 pregnancies conceived between June 1984 andJuly 1990 as a result of 7623 IVF cycles. Superovulation inductionwas achieved with human menopausal gonadotrophin (HMG) and/orpurified follicle stimulating hormone (FSH) together with eitherclomiphene citrate or the gonadotrophin hormone-releasing hormone(GnRH) agonist buserelin, the latter either as a short ‘flare’regimen or as a ‘long’ regimen to induce pituitarydesensitization. There were 282 spontaneous abortions (26.6%)and 54 ectopic pregnancies (5.1%). The mean age of women withongoing pregnancies was 32.2 (SD 3.9) years compared with 33.2(SD 4.1) years in those who miscarried, which were significantlydifferent (P = 0.008). There was no relation between the miscarriagerate and the indication for IVF. The miscarriage rate was 23.6%in women with normal ovaries compared with 35.8% in those withpolycystic ovaries [P = 0.0038, 95% confidence interval (CI)4.68–23.10%]. There was no difference in the miscarriagerate between treatment with HMG or FSH. Women whose ovarieswere normal on ultrasound were just as likely to miscarry ifthey were treated with clomiphene or with the long buserelinprotocol. Those with polycystic ovaries, however, had a significantreduction in the rate of miscarriage when treated with the longbuserelin protocol, 20.3% (15/74), compared with clomiphenecitrate, 47.2% (51/108) (P = 0.0003, 95% CI 13.82–40.09%).     

Threshold effect of urinary glycosaminoglycans and the walk test as indicators of disease progression in a survey of subjects with Mucopolysaccharidosis VI (Maroteaux-Lamy syndrome)

A cross-sectional survey in individuals affected with the lysosomal storage disease Mucopolysaccharidosis VI (MPS VI) was conducted to establish demographics, urinary glycosaminoglycan (GAG) levels, and clinical progression of the disease. The survey evaluated 121 bona fide MPS VI-affected individuals over the age of 4 years from 15 countries across the Americas, Europe, and Australasia representing greater than 10% of the estimated world prevalence of the disease. A medical history, complete physical exam, urinary GAG determination, and assessment of several clinical measures related to physical endurance, pulmonary function, joint range of motion, strength, and quality of life were completed for each participant. Although a wide variation in clinical presentation was observed, several general findings were obtained reflecting progression of the disease. Impaired physical endurance, as measured by the distance achieved in a 6-min walk, could be demonstrated across all age groups of MPS VI-affected individuals. High urinary GAG values (>200 mug/mg creatinine) were associated with an accelerated clinical course comprised of age-adjusted short stature and low body weight, impaired endurance, compromised pulmonary function, and reduced joint range of motion. An unexpected result was the predominance of urinary GAG values <100 mug/mg creatinine for those participants over the age of 20 years. Pending the collection of longitudinal data, these results suggest that urinary GAG levels predict clinical morbidity, and longer-term survival is associated with urinary GAG levels below a threshold of 100 mug/mg creatinine.     

IL-12p40-overexpressing immature dendritic cells induce T cell hyporesponsiveness in vitro but accelerate allograft rejection in vivo: role of NK cell activation and interferon-gamma production

Infusion of genetically modified dendritic cells (DC) expressing immunosuppressive molecules is a potential therapy for organ rejection. IL-12p70, a cytokine produced mainly by DC and macrophages, consists of two subunits, p40 and p35. IL-12p70 is an activator of T cells, while the IL-12p40 subunit serves as a natural antagonist for IL-12p70 action. The primary aim of this study was to evaluate the effect of IL-12p40 gene-modification on both the T-cell stimulatory activity of immature DC (imDC) and their ability to prolong cardiac allograft survival. IL-12p40 gene-modified imDC (DC-p40) exhibited a phenotype characteristic of imDC and displayed impaired T-cell allostimulatory ability in vitro. However, to our surprise, for murine vascularized heterotopic heart transplantation (HHT), administration of donor-derived DC-p40 7 days prior to transplantation did not prolong allograft survival but instead significantly exacerbated cardiac allograft rejection. Further study showed that DC-p40 augmented NK cell activity both in vitro and in vivo and enhanced interferon-gamma (IFN-gamma) production in vivo, which might be due to the increased IL-23 production by DC-p40. Our data suggested that although IL-12p40 gene-modified immature DC can induce T cell hyporesponsiveness in vitro, their ability to activate NK cells and induce IFN-gamma production counterbalances this, exacerbating cardiac allograft rejection. The unexpected effects of DC-p40 limit their value in promoting allograft survival in vivo and likely reflect the complexity of IL-12p40 biology.     

Status of oral rabies vaccination in wild carnivores in the United States

Persistence of multiple variants of rabies virus in wild Chiroptera and Carnivora presents a continuing challenge to medical, veterinary and wildlife management professionals. Oral rabies vaccination (ORV) targeting specific Carnivora species has emerged as an integral adjunct to conventional rabies control strategies to protect humans and domestic animals. ORV has been applied with progress toward eliminating rabies in red foxes (Vulpes vulpes) in western Europe and southern Ontario, Canada. More recently since 1995, coordinated ORV was implemented among eastern states in the U.S.A. to prevent spread of raccoon (Procyon lotor) rabies and to contain and eliminate variants of rabies virus in the gray fox (Urocyon cinereoargenteus) and coyote (Canis latrans) in Texas. In this paper, we describe the current cooperative ORV program in the U.S.A. and discuss the importance of coordination of surveillance and rabies control programs in Canada, Mexico and the U.S.A. Specifically, several priorities have been identified for these programs to succeed, which include additional oral vaccines, improved baits to reach target species, optimized ORV strategies, effective communication and legal strategies to limit translocation across ORV barriers, and access to sufficient long-term funding. These key priorities must be addressed to ensure that ORV has the optimal chance of achieving long range programmatic goals of eliminating specific variants of rabies virus in North American terrestrial carnivores.     

Essential role for caspase 8 in T-cell homeostasis and T-cell-mediated immunity

Defects in death receptor-mediated apoptosis have been linked to cancer and autoimmune disease in humans. The in vivo role of caspase 8, a component of this pathway, has eluded analysis in postnatal tissues because of the lack of an appropriate animal model. Targeted disruption of caspase 8 is lethal in utero. We generated mice with a targeted caspase 8 mutation that is restricted to the T-cell lineage. Despite normal thymocyte development in the absence of caspase 8, we observed a marked decrease in the number of peripheral T-cells and impaired T-cell response ex vivo to activation stimuli. caspase 8 ablation protected thymocytes and activated T-cells from CD95 ligand but not anti-CD3-induced apoptosis, or apoptosis activated by agents that are known to act through the mitochondria. caspase 8 mutant mice were unable to mount an immune response to viral infection, indicating that caspase 8 deletion in T-cells leads to immunodeficiency. These findings identify an essential, cell-stage-specific role for caspase 8 in T-cell homeostasis and T-cell-mediated immunity. This is consistent with the recent identification of caspase 8 mutations in human immunodeficiency.