Exploring altered bovine sperm trajectories by sperm tracking in unconfined conditions.

Mammalian sperm motility is getting more relevant due to rising infertility rates worldwide, generating the need to improve conventional analysis and diagnostic approaches. Nowadays, computer assisted sperm analysis (CASA) technologies represent a popular alternative to manual examination which is generally performed by observing sperm motility in very confined geometries. However, under physiological conditions, sperm describe three-dimensional motility patterns which are not well reconstructed by the limited depth of standard acquisition chambers. Therefore, affordable and more versatile alternatives are needed. Here, a motility analysis in unconfined conditions is proposed. In details, the analysis is characterized by a significant longer duration -with respect to conventional systems- with the aim to observe eventually altered motility patterns. Brightfield acquisition in rectangular glass capillaries captured frozen-thawed bovine spermatozoa which were analyzed by means of a self-written tracking routine and classified in sub-populations, based on their curvilinear velocity. To test the versatility of our approach, cypermethrin -a commonly used pesticides- known to be responsible for changes in sperm motility was employed, assessing its effect at three different time-steps. Experimental results showed that such drug induces an increase in sperm velocity and progressiveness as well as circular pattern formation, likely independent of wall interactions. Moreover, this resulted in a redistribution of sperm with the rapid class declining in number with time, but still showing an overall velocity increase. The flexibility of the approach permits parameter modifications with the experimental needs, allowing us to conduct a comprehensive examination of sperm motility. This adaptability facilitated data acquisition which can be computed at different frame rates, extended time periods, and within deeper observation chambers. The suggested approach for sperm analysis exhibits potential as a valuable augmentation to current diagnostic instruments.

Chemoenzymatic Late-Stage Modifications Enable Downstream Click-Mediated Fluorescent Tagging of Peptides.

Aromatic prenyltransferases from cyanobactin biosynthetic pathways catalyse the chemoselective and regioselective intramolecular transfer of prenyl/geranyl groups from isoprene donors to an electron-rich position in these macrocyclic and linear peptides. These enzymes often demonstrate relaxed substrate specificity and are considered useful biocatalysts for structural diversification of peptides. Herein, we assess the isoprene donor specificity of the N1-tryptophan prenyltransferase AcyF from the anacyclamide A8P pathway using a library of 22 synthetic alkyl pyrophosphate analogues, of which many display reactive groups that are amenable to additional functionalization. We further used AcyF to introduce a reactive moiety into a tryptophan-containing cyclic peptide and subsequently used click chemistry to fluorescently label the enzymatically modified peptide. This chemoenzymatic strategy allows late-stage modification of peptides and is useful for many applications.

Biochemical characterization of a cyanobactin arginine-N-prenylase from the autumnalamide biosynthetic pathway.

Cyanobactins are linear and cyclic post-translationally modified peptides. Here we show that the prenyl-D-Arg-containing autumnalamide A is a member of the cyanobactin family. Biochemical assays demonstrate that the AutF prenyltransferase targets the guanidinium moiety in arginine and homoarginine and is a useful tool for biotechnological applications.

Transitional-aged youth perceptions of influential factors for substance-use change and treatment seeking.

There is an evident disparity between the number of youth who report experiencing problematic substance use and the number who seek treatment. To address this disparity, it is important to understand the reasons youth do and do not seek substance use treatment. Using qualitative data obtained from semistructured interviews with 31 youth aged 17-25 years presenting for treatment at a mental health hospital, the current study identifies themes in the factors that youth identify as having influenced them to seek or delay treatment. In alignment with self-determination theory, youth identified internal factors, such as wanting to better their academic, social, or financial situation, and external factors, such as familial pressure, as motivating them to seek treatment. Factors beyond those encompassed by self-determination theory were also revealed as having influenced youth decisions to seek treatment for substance abuse. These predominantly included structural factors, including satisfaction with previous treatment, accessibility of services, and availability of clinicians. These findings provide important insight for first-contact professionals and service providers looking to enhance youth motivation to seek and engage in treatment. Limitations and opportunities for future research are discussed.

Sirenomelia with oligodactylia: early ultrasonographic and hysteroscopic embryoscopic diagnosis during the first trimester of gestation.

The case we describe reports the early sonographic findings of sirenomelia with oligodactylia at 9 weeks of gestation by transvaginal two-dimensional color Doppler ultrasonography imaging and its confirmation by hysteroscopic embryoscopy at 12 weeks to further characterize the findings. The embryo showed increased nuchal translucency and fused lower limbs with a large intra-abdominal vessel and two-vessel umbilical cords. The pregnancy was terminated by medical abortion induction after the patient viewed the embryoscopic images. Diagnosis is commonly made later in the second trimester of pregnancy, oligohydramnios being a warning signal, which usually makes the diagnosis difficult. Survival, only possible in the absence of renal agenesis, is extremely rare. In view of the extremely poor prognosis, early diagnosis allows for earlier counseling and less traumatic therapeutic termination of pregnancy.