Molekularzytogenetische Analysen zur Bedeutung des Inversionspolymorphismus in der Chromosomenregion 7q11.23 für die Entstehung des Williams-Beuren-Syndroms.

Ursache des Williams-Beuren-Syndrom (WBS) ist eine meist 1,5 Mb große Deletion in 7q11.23. 2001 wurde in der Literatur erstmals von einer erhöhten Inversionsrate des WBS spezifischen Bereiches bei Eltern von Kindern mit WBS berichtet. In dieser Studie wurde Blut von Eltern von Kindern mit WBS und einer Kontrollgruppe in Hinblick auf die Inversion 7q11.23 untersucht. Dazu wurde Dreifarb-Fluoreszenz-in-Situ-Hybridisierung verwendet. Die Inversionsrate war in der Elterngruppe (24 Paare) wie erwartet relativ hoch, in 20,8 % war mindestens einer der Partner Träger der Inversion. Aber auch in der Kontrollgruppe (51 Paare) konnte bei 13,7 % der Paare eine Inversion nachgewiesen werden. Außerdem konnte bei einem Kind gezeigt werden, dass die Inversion mit hoher Wahrscheinlichkeit keine Bedeutung bei der Deletionsentstehung hatte. Der Inversionspolymorphismus spielt dabei nach den Ergebnissen dieser Studie bei der Entstehung des WBS eine geringere Rolle als bisher angenommen

No effect of pre race supplementation with vitamins and minerals on performance in an ultra-endurance race

Intake of supplements such as vitamins and minerals is widespread in athletes. The aim of the study was the investigation of the influence of intake of vitamins and minerals before an ultra-endurance triathlon and its effect on race performance in a descriptive field study. Participants of the “Triple Iron Triathlon Germany 2006“ in Lensahn, Schleswig-Holstein, Germany, were contacted by a newsletter six weeks before the race by the organizer and received a questionnaire to fill in their intake of vitamins and minerals. Questionnaires were self-administered and not administered by trained personnel. During this race the athletes had to cover 11.4 km swimming, 540 km cycling and 126.6 km running within 58 hours. The athletes were divided into two categories: successful finishers with intake of vitamins and minerals and successful finishers without intake prior to the race. Race performance (total running time in h) of athletes with intake and athletes without intake of these substances was compared. In the four-week period prior to the race, nine athletes (53 %) ingested vitamins and eight athletes (47 %) minerals. Athletes with intake of vitamins (44.7 ± 7.0 h versus 50.4 ± 4.4h; p>0.05) and minerals (45.3 ± 7.2 versus 49.3 ± 5.4 h, p>0.05) finished the race not faster than athletes without intake of vitamins and minerals. In the “Triple Iron Triathlon Germany 2006“ in Lensahn, Germany, no influence on race performance was observed concerning the regular intake of vitamins and minerals in the last four weeks before the race

No significantly increased frequency of the inversion polymorphism at the WBS-critical region 7q11.23 in German parents of patients with Williams-Beuren syndrome as compared to a population control

<p>Abstract</p> <p>Background</p> <p>Typical Williams-Beuren syndrome (WBS) is commonly caused by a ~1.5 Mb - ~1.8 Mb heterozygous deletion of contiguous genes at chromosome region 7q11.23. The majority of WBS cases occurs sporadically but few familial cases of autosomal dominant inheritance have been reported. Recent data demonstrated the existence of the paracentric inversion polymorphism at the WBS critical region in 7q11.23 in some of the progenitors transmitting the chromosome which shows the deletion in the affected child. In parents having a child affected by WBS the prevalence of such a structural variant has been reported to be much higher (~25- ~30%) than in the general population (~1- ~6%). However, in these previously reported studies only a limited number of randomly selected patients and non transmitting parents of WBS patients were used as controls, but without specification of any clinical data. Therefore we have undertaken a German population-based molecular cytogenetic investigation. We evaluated the incidence of the paracentric inversion polymorphism at 7q11.23 analyzing interphase nuclei of lymphocytes using a three color fluorescence in situ hybridization (FISH) probe.</p> <p>Results</p> <p>FISH analysis was carried out on couples with a child affected by WBS as compared to a population sample composed of different normal individuals: Control group I: couples with two healthy children, control group II: couples with fertility problems, planning ICSI and control group III: couples with two healthy children and one child with a chromosome aberration, not involving region 7q11.23. The three color FISH assay showed that the frequency of the paracentric inversion polymorphism at 7q11.23 in couples with a child affected by WBS was 20.8% (5 out of 24 pairs) as compared to 8.3% (2 out of 24 pairs, control group I), 25% (4 out of 16 pairs, control group II) and 9.1% (1 out of 11 pairs, control group III), respectively (total 7 out of 51 pairs, 13.8%). The frequencies differed between the groups, but this was statistically not significant (p > 0.05, Fisher's test).</p> <p>Conclusion</p> <p>Our results do not support the hypothesis that the paracentric inversion polymorphism at 7q11.23 is a major predisposing factor for the WBS deletion.</p

Simulated Effects of Recruitment Variability, Exploitation, and Reduced Habitat Area on the Muskellunge Population in Shoepack Lake, Voyageurs National Park, Minnesota

The genetically unique population of muskellunge Esox masquinongy inhabiting Shoepack Lake in Voyageurs National Park, Minnesota, is potentially at risk for loss of genetic variability and long-term viability. Shoepack Lake has been subject to dramatic surface area changes from the construction of an outlet dam by beavers Castor canadensis and its subsequent failure. We simulated the long-term dynamics of this population in response to recruitment variation, increased exploitation, and reduced habitat area. We then estimated the effective population size of the simulated population and evaluated potential threats to long-term viability, based on which we recommend management actions to help preserve the long-term viability of the population. Simulations based on the population size and habitat area at the beginning of a companion study resulted in an effective population size that was generally above the threshold level for risk of loss of genetic variability, except when fishing mortality was increased. Simulations based on the reduced habitat area after the beaver dam failure and our assumption of a proportional reduction in population size resulted in an effective population size that was generally below the threshold level for risk of loss of genetic variability. Our results identified two potential threats to the long-term viability of the Shoepack Lake muskellunge population, reduction in habitat area and exploitation. Increased exploitation can be prevented through traditional fishery management approaches such as the adoption of no-kill, barbless hook, and limited entry regulations. Maintenance of the greatest possible habitat area and prevention of future habitat area reductions will require maintenance of the outlet dam built by beavers. Our study should enhance the long-term viability of the Shoepack Lake muskellunge population and illustrates a useful approach for other unique populations

Risk profile of the RET A883F germline mutation: an international collaborative study

Context: The A883F germline mutation of the REarranged during Transfection proto-oncogene causes multiple endocrine neoplasia 2B. In the revised American Thyroid Association (ATA) guidelines for the management of medullary thyroid carcinoma (MTC) the A883F mutation has been reclassified from the highest to high risk level, although no well-defined risk profile for this mutation exists. Objective: To create a risk profile for the A883F mutation for appropriate classification in the ATA risk levels. Design: Retrospective analysis. Setting: International collaboration. Patients: Included were 13 A883F carriers. Intervention: The intervention was thyroidectomy. Main Outcome Measures: Earliest age of MTC, regional lymph node metastases, distant metastases, age-related penetrance of MTC and pheochromocytoma (PHEO), overall and disease-specific survival and biochemical cure rate. Results: One and three carriers were diagnosed at age 7-9 years (median 7.5) with a normal thyroid and C-cell hyperplasia, respectively. Nine carriers had MTC diagnosed at age 10-39 years (median 19). The earliest age of MTC, regional lymph node and distant metastasis were 10, 20, 20 years, respectively. Fifty percent penetrance of MTC and PHEO was achieved by age 19 and 34 years, respectively. Five- and 10-year survival (both overall and disease-specific) were 88% and 88%, respectively. Biochemical cure for MTC at latest follow-up was achieved in 63% (5/8 carriers) with pertinent data. Conclusions: MTC of A883F carriers seems to have a more indolent natural course compared to that of M918T carriers. Our results support the classification of the A883F mutation in the ATA high risk level

Population Dynamics and Angler Exploitation of the Unique Muskellunge Population in Shoepack Lake, Voyageurs National Park, Minnesota

A unique population of muskellunge Esox masquinongy inhabits Shoepack Lake in Voyageurs National Park, Minnesota. Little is known about its status, dynamics, and angler exploitation, and there is concern for the long-term viability of this population. We used intensive sampling and mark–recapture methods to quantify abundance, survival, growth, condition, age at maturity and fecundity and angler surveys to quantify angler pressure, catch rates, and exploitation. During our study, heavy rain washed out a dam constructed by beavers Castor canadensis which regulates the water level at the lake outlet, resulting in a nearly 50% reduction in surface area. We estimated a population size of 1,120 adult fish at the beginning of the study. No immediate reduction in population size was detected in response to the loss of lake area, although there was a gradual, but significant, decline in population size over the 2-year study. Adults grew less than 50 mm per year, and relative weight (W r) averaged roughly 80. Anglers were successful in catching, on average, two fish during a full day of angling, but harvest was negligible. Shoepack Lake muskellunge exhibit much slower growth rates and lower condition, but much higher densities and angler catch per unit effort (CPUE), than other muskellunge populations. The unique nature, limited distribution, and location of this population in a national park require special consideration for management. The results of this study provide the basis for assessing the long-term viability of the Shoepack Lake muskellunge population through simulations of long-term population dynamics and genetically effective population size

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

A population and angler use assessment of muskellunge in Shoepack Lake, Voyageurs National Park, Minnesota

Shoepack Lake in Voyageurs National Park, Minnesota, supports a genetically unique population of muskellunge. Over a two-year period, we collected population data using multiple mark-recapture methods and exploitation data from angler surveys. Additional fieldwork yielded data on age structure, growth, age of maturity and fecundity. We estimated the initial adult population size to be 1120 fish (95% confidence interval - 842-1399). Angler surveys revealed catch rates averaging 0.262 fish per angler per hour. Anglers harvested few fish in part because only 4% of captured fish were above the 762 mm minimum length. Natural mortality was estimated as 0.0451. Female growth rates were <50 mm a year with little or no growth beyond 722 mm. Male growth rates were <50 mm a year with little or no growth beyond 663 mm. Growth rates, ultimate lengths, and condition were lower than reported for lakes in Ontario and Wisconsin. Rain-induced washout of a large beaver dam reduced the surface area of Shoepack Lake by roughly one-half during our study, providing dramatic evidence for potential future environmental changes. We estimated the ratio of effective population size (N[subscript e]) to absolute population size (N) using demographic data. We generated a set of potential scenarios based on our data, literature values and reasonable assumptions about angler exploitation, environmental conditions and carrying capacity. We then simulated the effects of each scenario on future population size using Fisheries Analysis and Simulation Tools (FAST) for 100 years, and used our calculated N[subscript e] to N ratio to estimate simulated N[subscript e] in each simulation year. Simulated N[subscript e] ranged from 165-855. Scenarios yielded N[subscript e] ranging from completely below to completely above the "500" guideline in which populations are considered "safe" from significant erosion of genetic variation. Reduction of carrying capacity, such as would be expected to occur following surface area reductions like the one we witnessed, was the primary cause of low N[subscript e] values in our simulations. Our results suggest that both natural phenomena and future changes in exploitation could threaten the genetic variability of the muskellunge population in Shoepack Lake. We recommend Voyageurs Nation Park maximize carrying capacity and reduce angler related mortalities.</p