Exploring the Structurally Conserved Regions and Functional Significance in Bacterial N-Terminal Nucleophile (Ntn) Amide-Hydrolases.

The initial adoption of penicillin as an antibiotic marked the start of exploring other compounds essential for pharmaceuticals, yet resistance to penicillins and their side effects has compromised their efficacy. The N-terminal nucleophile (Ntn) amide-hydrolases S45 family plays a key role in catalyzing amide bond hydrolysis in various compounds, including antibiotics like penicillin and cephalosporin. This study comprehensively analyzes the structural and functional traits of the bacterial N-terminal nucleophile (Ntn) amide-hydrolases S45 family, covering penicillin G acylases, cephalosporin acylases, and D-succinylase. Utilizing structural bioinformatics tools and sequence analysis, the investigation delineates structurally conserved regions (SCRs) and substrate binding site variations among these enzymes. Notably, sixteen SCRs crucial for substrate interaction are identified solely through sequence analysis, emphasizing the significance of sequence data in characterizing functionally relevant regions. These findings introduce a novel approach for identifying targets to enhance the biocatalytic properties of N-terminal nucleophile (Ntn) amide-hydrolases, while facilitating the development of more accurate three-dimensional models, particularly for enzymes lacking structural data. Overall, this research advances our understanding of structure-function relationships in bacterial N-terminal nucleophile (Ntn) amide-hydrolases, providing insights into strategies for optimizing their enzymatic capabilities.

Histopathological and statistical study of corneal repair in rabbits. A new way to understand corneal recovery.

The study aims to evaluate corneal healing post amniotic membrane transplantation in controlled corneal defects, justifying its application in routine ophthalmology practice. The objective is to establish a reliable method for assessing the repair process. In three groups of six adult New Zealand rabbits, keratectomy and a monolayer transplant of dehydrated human amniotic membrane (AM) were conducted in the left eye (OS) with the right eye (OD) serving as the control eye. Clinical signs were assessed, and both eyes were enucleated at 1, 2, and 4 weeks for optical coherence tomography (OCT) measurements and histological analysis, collecting data from different epithelium, stroma, and limbus regions. This study was conducted using a formula that combines histologic data categorizing their presence and/or type as beneficial for corneal repair. No statistically significant differences were found between the experimental and control eyes regarding all clinical signs and OCT measurements. However, a linear model using histopathological results showed a period-implant mode interaction with statistical significance (p=0.010). The use of the single-layer amniotic membrane resulted in improved corneal recovery with the stromal side showing better performance in the first week and the epithelial side proving to be more effective than the stromal side in the long term. For the first time, a statistical formula employing histopathological data is introduced to determine corneal recovery, potentially offering a more accurate and reliable method compared with the observation of clinical signs and corneal measurements with OCT.

Analysis of EEG and ECG in women with intimate partner violence experience during an emotional task.

Intimate Partner Violence (IPV) has been associated with cognitive, emotional, physical and physiological alterations, and with the presence of anxiety disorders. There is not enough research on this problem from an interdisciplinary approach despite the above. Therefore, this research compared the emotion perception and electrophysiological responses, elicited by an emotional task, in women who had experienced IPV and women who had not (WIPV). Forty-five participants (22 with and 23 without IPV experience) were presented with nine images from the International Affective Picture System (IAPS) database and performed a self-report using the Self-Assessment Manikin (SAM). In parallel, electrophysiological signals (ECG and EEG) were acquired, for the analysis of emotional response. In the between-group analysis, the IPV group showed lower perceived dominance and greater central asymmetry in the alpha band than the WIPV group; additionally, the IPV group exhibited a significant positive correlation between the valence of the images and the alpha band power in central areas. In the within-group analysis, the WIPV group showed greater activation in the alpha band and alpha/beta ratio in frontal areas during the emotional elicitation, as compared to baseline. Furthermore, the ECG analysis showed that, for the IPV group, there was a decrease in the power of the high-frequency (HF) band and an increase in the power of the very-low-frequency (VLF) band of heart rate variability (HRV) during the elicitation stage. It is hypothesized that the IPV group could present higher stress levels and greater physiological activity during emotional stimuli than the WIPV group. Possible changes in emotional regulation and anxiety levels due to IPV experiences are discussed.