Vedelsalinas8176
Bardet-Biedl syndrome (BBS) is a ciliopathy with a wide spectrum of symptoms due to primary cilia dysfunction, including genitourinary developmental anomalies as well as impaired reproduction, particularly in males. Primary cilia are known to be required at the following steps of reproduction function (i) genitourinary organogenesis, (ii) in fetal firing of hypothalamo-pituitary axe, (iii) sperm flagellum structure, and (iv) first zygotic mitosis conducted by proximal sperm centriole. BBS phenotype is not fully understood.
This study explored all steps of reproduction in 11 French male patients with identified BBS mutations.
BBS patients frequently presented with genitourinary malformations, such as cryptorchidism (5/11), short scrotum (5/8), and micropenis (5/8), but unexpectedly, with normal testis size (7/8). Ultrasonography highlighted epididymal cysts or agenesis of one seminal vesicle in some cases. Sexual hormones levels were normal in all patients except one. Sperm numeration was normal in 8 out of the 10 obtained samples. Five to 45% of sperm presented a progressive motility. Electron microscopy analysis of spermatozoa did not reveal any homogeneous abnormality. Moreover, a psychological approach pointed to a decreased self-confidence linked to blindness and obesity explaining why so few BBS patients express a child wish.
Primary cilia dysfunction in BBS impacts the embryology of the male genital tract, especially epididymis, penis, and scrotum through an insufficient fetal androgen production. However, in adults, sperm structure does not seem to be impacted. These results should be confirmed in a greater BBS patient cohort, focusing on fertility.
Primary cilia dysfunction in BBS impacts the embryology of the male genital tract, especially epididymis, penis, and scrotum through an insufficient fetal androgen production. However, in adults, sperm structure does not seem to be impacted. These results should be confirmed in a greater BBS patient cohort, focusing on fertility.
Physiological alterations challenge the assessment of maternal thyroid function in pregnancy. It remains uncertain how the reference ranges vary by week of pregnancy, and how the classification of disease varies by analytical method and type of thyroid function test.
Serum samples from Danish pregnant women (n = 6282) were used for the measurement of thyrotropin (TSH), total and free thyroxine (T4), total and free 3,5,3'-triiodothyronine (T3), and T-uptake using "Method A" (Cobas 8000, Roche Diagnostics). TSH and free T4 were also measured using "Method B" (ADVIA Centaur XP, Siemens Healthineers).
Pregnancy week- and method-specific reference ranges were established among thyroid antibody-negative women (n = 4612). The reference ranges were used to classify maternal thyroid function, and results were compared by analytical method and type of thyroid function test.
The reference ranges for TSH showed a gradual decrease during pregnancy weeks 4 to 14, a gradual increase was observed for total T4, total T3, and T-uptake, whereas free T4 and free T3 showed less variation. When TSH and free T4 were used, Method A classified 935 (14.9%) with abnormal thyroid function, Method B a total of 903 (14.4%), and the methods agreed on 554 individuals. When TSH and total T4 were used, 947 (15.1%) were classified with abnormal thyroid function, and classifications by either total T4 or free T4 agreed on 584 individuals.
Even when pregnancy week- and method-specific reference ranges were established, the classification of maternal thyroid dysfunction varied considerably by analytical method and type of thyroid function test.
Even when pregnancy week- and method-specific reference ranges were established, the classification of maternal thyroid dysfunction varied considerably by analytical method and type of thyroid function test.In the mammalian glutamate transporters, countertransported intracellular K+ is essential for relocating the glutamate binding site to the extracellular side of the membrane. This K+-dependent process is believed to be rate limiting for the transport cycle. check details In contrast, extracellular K+ induces glutamate release upon transporter reversal. Here, we analyzed potential K+ binding sites using molecular dynamics (MD) simulations and site-directed mutagenesis. Two candidate sites were identified by spontaneous K+ binding in MD simulations, one site (K1 site) overlapping with the Na1 Na+ binding site and the K2 site being localized under hairpin loop 2 (HP2). Mutations to conserved amino acid residues in these sites resulted in several transporters that were defective in K+-induced reverse transport and which bound K+ with reduced apparent affinity compared with the wild-type transporter. However, external K+ interaction was abolished in only one mutant transporter EAAC1D454A in the K1 site. Our results, for the first time, directly demonstrate effects of K1-site mutations on K+ binding, in contrast to previous reports on K+ binding sites based on indirect evidence. We propose that K+ binding to the K1 site is responsible for catalyzing the relocation step, whereas binding to the K2 site may have an as-of-yet unidentified regulatory function.Capybara (Hydrochoerus hydrochaeri) is the largest species among the extant rodents. The draft genome of capybara was sequenced with the estimated genome size of 2.6 Gb. Although capybara is about 60 times larger than guinea pig, comparative analyses revealed that the neutral evolutionary rates of the two species were not substantially different. However, analyses of 39 mammalian genomes revealed very heterogeneous evolutionary rates. The highest evolutionary rate, 8.5 times higher than the human rate, was found in the Cricetidae-Muridae common ancestor after the divergence of Spalacidae. Muridae, the family with the highest number of species among mammals, emerged after the rate acceleration. Factors responsible for the evolutionary rate heterogeneity were investigated through correlations between the evolutionary rate and longevity, gestation length, litter frequency, litter size, body weight, generation interval, age at maturity, and taxonomic order. The regression analysis of these factors showed that the model with three factors (taxonomic order, generation interval, and litter size) had the highest predictive power (R2 = 0.