A shell finite element model of the pelvic floor muscles

The pelvic floor gives support to the organs in the abdominal cavity. Using the dataset made public in (Janda et al. J. Biomech. (2003) 36(6), pp. 749-757), we have reconstructed the geometry of one of the most important parts of the pelvic floor, the levator ani, using NURB surfaces. Once the surface is triangulated, the corresponding mesh is used in a finite element analysis with shell elements.Based on the 3D behavior of the muscle we have constructed a shell that takes into account the direction of the muscle fibers and the incompressibility of the tissue. The constitutive model for the isotropic strain energy and the passive strain energy stored in the fibers is adapted from Humphrey's model for cardiac muscles. To this the active behavior of the skeletal muscle is added.We present preliminary results of a simulation of the levator ani muscle under pressure and with active contraction. This research aims at helping simulate the damages to the pelvic floor that can occur after childbirth.     

Origin of the disjunct tetraploid Cardamine amporitana (Brassicaceae) assessed with nuclear and chloroplast DNA sequence data

Seventy-four nucleotide sequences from the ITS regions of nuclear ribosomal DNA and 76 from the trnL-trnF spacer of chloroplast DNA were used to address the origin of tetraploid Cardamine amporitana, the conspecifity of central Italian and northeastern Spanish populations, and the possible cause for such geographic disjunction. Because of the complex lineage relationships in Cardamine, the sampling included 22 taxa. In the results, both data sets are highly congruent in supporting a close relationship of C. amporitana to the widespread Eurasian C. amara. Low genetic variability in northeastern Spanish populations of C. amporitana suggests long-distance dispersal from central Italy. The interior position of the single northeastern Spanish haplotype in a statistical parsimony network of trnL-trnF haplotypes however does not support this scenario and invokes other plausible phylogeographic explanations. The disappearance of geographically intermediate populations and genetic impoverishment by migration and isolation, both probably associated with Quaternary climatic oscillations, appears as an alternative hypothesis to explain the phylogeographic pattern. A recent hybridization event is reported between C. amporitana and a diploid from the C. pratensis group in central Italy on the basis of additive polymorphisms in ITS for all the 22 distinguishing nucleotides.     

Influence of the Use of Statin on the Stability of Erythrocyte Membranes in Multiple Sclerosis

Multiple sclerosis (MS) probably occurs by oxidative, inflammatory and autoimmune mechanisms. This study investigated the influence of statin on the stability of erythrocyte membranes in MS patients. The population was composed of one group with simvastatin therapy (20 mg/day), another group without statin therapy and a healthy control group. The stability of erythrocytes was evaluated by the half-transition points, H₅₀ and D₅₀, obtained from the curves of hemolysis induced by hypotonic shock and ethanol action, respectively. Erythrocytes of MS patients were less stable against lysis by both chaotropes. This behavior may be merely a consequence of the lifestyle of MS patients or it may be intrinsically associated with the conjunct of factors responsible for the development of the disease. The use of statin by MS patients was associated with lower levels of LDL and total cholesterol, as expected, and with higher stability of erythrocytes against ethanol compared to the values of untreated MS patients.     

Chromosome numbers and pollen fertility in the Senecio nemorensis group (Compositae) in the Carpathians

New chromosome numbers for two species from the Senecio nemorensis group: S. dacicus (2n = 40) and S. ucranicus (2n = 40) have been ascertained. The counts for S. germanicus Wallr. subsp. germanicus (2n = 40), S. hercynicus Herborg subsp. hercynicus (2n = 40), S. ovatus (P. Gaertn. et al.) Willd. subsp. ovatus (2n = 40) occurring in the Carpathians are also reported. The study confirmed only the known tetraploid chromosome number for the taxa of this group. The pollen fertility ranged from 82.09 to 92.99% in all examined species and subspecies, including their hybrids.     

National,Regional, and Global Trends in Infertility Prevalence Since 1990: A Systematic Analysis of 277 Health Surveys

Background

Global, regional, and national estimates of prevalence of and tends in infertility are needed to target prevention and treatment efforts. By applying a consistent algorithm to demographic and reproductive surveys available from developed and developing countries, we estimate infertility prevalence and trends, 1990 to 2010, by country and region.

Methods and Findings

We accessed and analyzed household survey data from 277 demographic and reproductive health surveys using a consistent algorithm to calculate infertility. We used a demographic infertility measure with live birth as the outcome and a 5-y exposure period based on union status, contraceptive use, and desire for a child. We corrected for biases arising from the use of incomplete information on past union status and contraceptive use. We used a Bayesian hierarchical model to estimate prevalence of and trends in infertility in 190 countries and territories. In 2010, among women 20–44 y of age who were exposed to the risk of pregnancy, 1.9% (95% uncertainty interval 1.7%, 2.2%) were unable to attain a live birth (primary infertility). Out of women who had had at least one live birth and were exposed to the risk of pregnancy, 10.5% (9.5%, 11.7%) were unable to have another child (secondary infertility). Infertility prevalence was highest in South Asia, Sub-Saharan Africa, North Africa/Middle East, and Central/Eastern Europe and Central Asia. Levels of infertility in 2010 were similar to those in 1990 in most world regions, apart from declines in primary and secondary infertility in Sub-Saharan Africa and primary infertility in South Asia (posterior probability [pp] ≥0.99). Although there were no statistically significant changes in the prevalence of infertility in most regions amongst women who were exposed to the risk of pregnancy, reduced child-seeking behavior resulted in a reduction of primary infertility among all women from 1.6% to 1.5% (pp = 0.90) and a reduction of secondary infertility among all women from 3.9% to 3.0% (pp>0.99) from 1990 to 2010. Due to population growth, however, the absolute number of couples affected by infertility increased from 42.0 million (39.6 million, 44.8 million) in 1990 to 48.5 million (45.0 million, 52.6 million) in 2010. Limitations of the study include gaps in survey data for some countries and the use of proxies to determine exposure to pregnancy.

Conclusions

We analyzed demographic and reproductive household survey data to reveal global patterns and trends in infertility. Independent from population growth and worldwide declines in the preferred number of children, we found little evidence of changes in infertility over two decades, apart from in the regions of Sub-Saharan Africa and South Asia. Further research is needed to identify the etiological causes of these patterns and trends. Please see later in the article for the Editors'' Summary     

Molecular analysis as an aid to assess the public health risk of non-O157 Shiga toxin-producing Escherichia coli strains

Shiga toxin-producing Escherichia coli (STEC) strains are commensal bacteria in cattle with high potential for environmental and zoonotic transmission to humans. Although O157:H7 is the most common STEC serotype, there is growing concern over the emergence of more than 200 highly virulent non-O157 STEC serotypes that are globally distributed, several of which are associated with outbreaks and/or severe human illness such as hemolytic-uremic syndrome (HUS) and hemorrhagic colitis. At present, the underlying genetic basis of virulence potential in non-O157 STEC is unknown, although horizontal gene transfer and the acquisition of new pathogenicity islands are an expected origin. We used seropathotype classification as a framework to identify genetic elements that distinguish non-O157 STEC strains posing a serious risk to humans from STEC strains that are not associated with severe and epidemic disease. We report the identification of three genomic islands encoding non-LEE effector (nle) genes and 14 individual nle genes in non-O157 STEC strains that correlate independently with outbreak and HUS potential in humans. The implications for transmissible zoonotic spread and public health are discussed. These results and methods offer a molecular risk assessment strategy to rapidly recognize and respond to non-O157 STEC strains from environmental and animal sources that might pose serious public health risks to humans.     

Time of ovulation in nulliparous and multiparous goats

Fifteen nulliparous and nine multiparous Serrana goats were used, through two successive oestrous cycles, in order to characterize their ovulation time with regard to the number of ovulations after induced and natural oestrus during the breeding season. The onset of oestrus was detected by the amount of vasectomized bucks after oestrus synchronization with prostaglandin, given 10 days apart, and in the following two expected natural oestrus. The preovulatory LH peak was determined from blood samples collected 0, 4, 8, 12, 16, 20 and 24 h after onset of oestrus. A transrectal ovarian ultrasound scanning was performed 20, 24, 28, 32, 36, 40, 44 and 60 h after onset of oestrus, for the detection of ovulations by means of the disappearance of large follicles (>4 to 5 mm). Single ovulations were observed in 76% of oestrous periods in nulliparous goats and in 18% of nulliparous goats. The onset of oestrus to LH peak interval was lower in nulliparous (12.1 ± 0.9 h, n = 38) than in multiparous (15.6 ± 1.0 h, n = 22, P < 0.05) goats with no oestrus interaction effects (P > 0.05). The LH peak to first ovulation interval was higher after natural (18.9 ± 0.7 h, n = 36) than after induced (15.8 ± 1.2 h, n = 24, P < 0.05) oestrus. The onset of oestrus to total ovulation interval was influenced by parity (P < 0.01) and oestrus type (P < 0.05) with a length of 30.1 ± 1.1 h (n = 15) and 33.4 ± 1.5 h (n = 9) for induced oestrus of nulliparous and multiparous goats, respectively, and 32.5 ± 1.0 h (n = 23) and 36.5 ± 1.1 h (n = 13) for natural oestrus of nulliparous and multiparous goats, respectively. The onset of oestrus to first ovulation interval was not influenced by parity, but an interval of 8.0 ± 1.6 h was observed between the first and second ovulations in polyovulatory oestrus. Consequently, nulliparous goats that are predominantly monovular ovulate earlier than multiparous goats that are predominantly polyovulatory. In conclusion, significant differences occurred in the number and time of ovulations between nulliparous and multiparous goats. More research is necessary for a deeper understanding of the mechanisms regulating monovularory and polyovulatory oestrous cycles regarding the parity of goats.