Anatomical variations of the brachial plexus in adult cadavers: A descriptive study and clinical significance.

BACKGROUND: Brachial plexus injury is recognized as one of the most severe clinical challenges due to the complex anatomical configuration of the brachial plexus and its propensity for variation, which complicates safe clinical interventions. This study aimed to ascertain the prevalence and characterize the types of brachial plexus variations, and to elucidate their clinical implications. MATERIALS AND METHODS: We conducted meticulous dissections of 60 formalin-fixed cadavers' upper arm, axilla and lower neck to reveal and assess the roots, trunks, divisions, cords, and branches of the brachial plexus. The pattern of branching was noted by groups of dissecting medical students and confirmed by the senior anatomists. The variations discovered were record and photographed using a digital camera for further analysis. RESULTS: Variations in the brachial plexus were identified in 40 of the 60 cadavers, yielding a prevalence rate of 66.7%. These variations were classified into root anomalies (2.1%), trunk anomalies (8.5%), division anomalies (2.1%), and cord anomalies (4.3%). Notably, anomalies in communicating branches were observed in 39 cadavers (83.0%): 14 with bilateral anomalies, 14 with anomalies on the left side, and 11 on the right side. These communicating branches formed connections between the roots and other segments, including trunks, cords, and terminal nerves, and involved the median, musculocutaneous, and ulnar nerves. CONCLUSION: The frequency and diversity of brachial plexus variations, particularly in communicating branches, are significant in cadavers. It is imperative that these variations are carefully considered during the diagnostic process, treatment planning, and prior to procedures such as supraclavicular brachial plexus blocks and nerve transfers, to mitigate the risk of iatrogenic complications.

MicroRNA-137-3p Protects PC12 Cells Against Oxidative Stress by Downregulation of Calpain-2 and nNOS.

The imbalance between excess reactive oxygen species (ROS) generation and insufficient antioxidant defenses contribute to a range of neurodegenerative diseases. High ROS levels damage cellular macromolecules such as DNA, proteins and lipids, leading to neuron vulnerability and eventual death. However, the underlying molecular mechanism of the ROS regulation is not fully elucidated. Recently, an increasing number of studies suggest that microRNAs (miRNAs) emerge as the targets in regulating oxidative stress. We recently reported the neuroprotective effect of miR-137-3p for brachial plexus avulsion-induced motoneuron death. The present study is sought to investigate whether miR-137-3p also could protect PC12 cells against hydrogen peroxide (H2O2) induced neurotoxicity. By using cell viability assay, ROS assay, gene and protein expression assay, we found that PC-12 cells exposed to H2O2 exhibited decreased cell viability, increased expression levels of calpain-2 and neuronal nitric oxide synthase (nNOS), whereas a decreased miR-137-3p expression. Importantly, restoring the miR-137-3p levels in H2O2 exposure robustly inhibited the elevated nNOS, calpain-2 and ROS expression levels, which subsequently improved the cell viability. Furthermore, the suppressive effect of miR-137-3p on the elevated ROS level under oxidative stress was considerably blunted when we mutated the binding site of calpain-2 targted by miR-137-3p, suggesting the critical role of calpain-2 involving the neuroprotective effect of miR-137-3p. Collectively, these findings highlight the neuroprotective role of miR-137-3p through down-regulating calpain and NOS activity, suggesting its potential role for combating oxidative stress insults in the neurodegenerative diseases.

Cultivation of humanistic values in medical education through anatomy pedagogy and gratitude ceremony for body donors.

BACKGROUND: One of the most important objectives of modern medical education is to empower medical students to become humanistic clinicians. Human anatomy plays a crucial role in this mission by using cadavers to cause reflections on death, dying, illness, and the role of medical practitioners in humanistic care. The objective of this study was to introduce, describe, and evaluate the impact of a ceremony in honor of the body donors on ethical and humanistic attitudes of medical students. METHODS: We used a phenomenological research approach to explore and understand the lived experiences of the anatomy teachers as they teach anatomy in the context of humanism and ethics. A separate survey of third-year medical students was carried out to understand their perceptions of changes in themselves, respect for donors and donor families, and their relationship with patients. Data were collected in two phases: a desktop review of teaching materials followed by in-depth interviews of the main anatomy teachers followed by a self-administered, 5-item Likert scaled questionnaire given to students. RESULTS: In the present article, we describe the rituals conducted in honor of body donors at our School of Medicine. We also describe the lived experiences of anatomy teachers as they work on improving humanistic education quality through the introduction of the concept of "silent mentor" which refers to a cadaver that quietly allows medical students to learn from it. In turn, a ceremony in honor of body donors who have altruistically donated their bodies so that learning anatomy through dissection would be possible is also introduced. A survey of the impact of the ceremony in honor of body donors on medical students revealed positive responses in terms of promoting studying anatomy (3.96 Vs 3.95) as well as reflections on own death (4.44 Vs 4.35), the life of body donors (4.07 Vs 4.04), and how to humanely view future patients and their significant others (4.32 Vs 4.24) relative to those that did not attend the ceremony (5-item Likert scale). The majority of the students that attended the ceremony also indicated that it had a positive impact on their future doctor-patient relationship, thinking about the possibility of donating their body for teaching as well as about medical ethics. Most of them also think that attending the ceremony helped reduce their anxiety, fear, and disgust of seeing corpses or dissecting and 90% insisted that memorial ceremonies should continue being conducted at Zhongshan Medical School. CONCLUSION: The combination of the anatomy component of the basic medical curriculum and gratitude ceremonies as well as activities to promote body bequeathal programs might help to accomplish the goal of cultivating high-quality medical students and professionals for the future. The long-term benefits would be a medical graduate who exudes empathy, relates well with patients and their significant others, leading to a productive doctor-patient relationship.

MiR-137-3p rescue motoneuron death by targeting calpain-2.

Brachial plexus root avulsion (BPRA) is a type of injury that leads to motor function loss as a result of motoneurons (MNs) degeneration. Here we identified that the reduced expression of rat miR-137-3p in the ventral horn of spinal cord was associated with MNs death. However, the pathophysiological role of miR-137-3p in root avulsion remains poorly understood. We demonstrated that the calcium-activated neutral protease-2 (calpain-2) was a direct target gene of miR-137-3p with miR-137-3p binding to the 3'-untranslated region of calpain-2. Silencing of calpain-2 suppressed the expression of neuronal nitric oxide synthase (nNOS), a primary source of nitric oxide (NO). After avulsion 2 weeks, up-regulation of miR-137-3p in the spinal cord reduced calpain-2 levels and nNOS expression inside spinal MNs, resulting in an amelioration of the MNs death. These events provide new insight into the mechanism by which upregulation of miR-137-3p can impair MN survival in the BPRA.

Does training improve diagnostic accuracy and inter-rater agreement in applying the Berlin radiographic definition of acute respiratory distress syndrome? A multicenter prospective study.

BACKGROUND: Poor inter-rater reliability in chest radiograph interpretation has been reported in the context of acute respiratory distress syndrome (ARDS), although not for the Berlin definition of ARDS. We sought to examine the effect of training material on the accuracy and consistency of intensivists' chest radiograph interpretations for ARDS diagnosis. METHODS: We conducted a rater agreement study in which 286 intensivists (residents 41.3%, junior attending physicians 35.3%, and senior attending physician 23.4%) independently reviewed the same 12 chest radiographs developed by the ARDS Definition Task Force ("the panel") before and after training. Radiographic diagnoses by the panel were classified into the consistent (n = 4), equivocal (n = 4), and inconsistent (n = 4) categories and were used as a reference. The 1.5-hour training course attended by all 286 intensivists included introduction of the diagnostic rationale, and a subsequent in-depth discussion to reach consensus for all 12 radiographs. RESULTS: Overall diagnostic accuracy, which was defined as the percentage of chest radiographs that were interpreted correctly, improved but remained poor after training (42.0 ± 14.8% before training vs. 55.3 ± 23.4% after training, p < 0.001). Diagnostic sensitivity and specificity improved after training for all diagnostic categories (p < 0.001), with the exception of specificity for the equivocal category (p = 0.883). Diagnostic accuracy was higher for the consistent category than for the inconsistent and equivocal categories (p < 0.001). Comparisons of pre-training and post-training results revealed that inter-rater agreement was poor and did not improve after training, as assessed by overall agreement (0.450 ± 0.406 vs. 0.461 ± 0.575, p = 0.792), Fleiss's kappa (0.133 ± 0.575 vs. 0.178 ± 0.710, p = 0.405), and intraclass correlation coefficient (ICC; 0.219 vs. 0.276, p = 0.470). CONCLUSIONS: The radiographic diagnostic accuracy and inter-rater agreement were poor when the Berlin radiographic definition was used, and were not significantly improved by the training set of chest radiographs developed by the ARDS Definition Task Force. TRIAL REGISTRATION: The study was registered at ClinicalTrials.gov (registration number NCT01704066 ) on 6 October 2012.

Propofol Protects Against H2O2-Induced Oxidative Injury in Differentiated PC12 Cells via Inhibition of Ca(2+)-Dependent NADPH Oxidase.

Propofol (2,6-diisopropylphenol) is a widely used general anesthetic with anti-oxidant activities. This study aims to investigate protective capacity of propofol against hydrogen peroxide (H2O2)-induced oxidative injury in neural cells and whether the anti-oxidative effects of propofol occur through a mechanism involving the modulation of NADPH oxidase (NOX) in a manner of calcium-dependent. The rat differentiated PC12 cell was subjected to H2O2 exposure for 24 h to mimic a neuronal in vitro model of oxidative injury. Our data demonstrated that pretreatment of PC12 cells with propofol significantly reversed the H2O2-induced decrease in cell viability, prevented H2O2-induced morphological changes, and reduced the ratio of apoptotic cells. We further found that propofol attenuated the accumulation of malondialdehyde (biomarker of oxidative stress), counteracted the overexpression of NOX core subunit gp91(phox) (NOX2) as well as the NOX activity following H2O2 exposure in PC12 cells. In addition, blocking of L-type Ca(2+) channels with nimodipine reduced H2O2-induced overexpression of NOX2 and caspase-3 activation in PC12 cells. Moreover, NOX inhibitor apocynin alone or plus propofol neither induces a significant downregulation of NOX activity nor increases cell viability compared with propofol alone in the PC12 cells exposed to H2O2. These results demonstrate that the protective effects of propofol against oxidative injury in PC12 cells are mediated, at least in part, through inhibition of Ca(2+)-dependent NADPH oxidase.

Co-Graft of Bone Marrow Stromal Cells and Schwann Cells Into Acellular Nerve Scaffold for Sciatic Nerve Regeneration in Rats.

PURPOSE: The conventional strategy for bridging large nerve defects, namely nerve autograft transplantation, results in donor-site morbidity. This detrimental consequence currently drives the search for alternatives. The authors used an acellular nerve scaffold filled with bone marrow stromal cells (BMSCs) and Schwann cells (SCs) to enhance regeneration. MATERIALS AND METHODS: In 60 adult rats, a 10-mm sciatic nerve defect was bridged with a nerve autograft (positive control), an acellular nerve scaffold (negative control), an acellular nerve scaffold with BMSCs (group I), an acellular nerve scaffold with SCs (group II), or an acellular nerve scaffold with BMSCs plus SCs (group III). After regenerating for 4 and 16 weeks after surgery, nerve regeneration was functionally assessed by a walking track analysis. The compound muscle action potential (CMAP), nerve conduction velocity (NCV) along regenerated sciatic nerves, and gastrocnemius muscle index (GMI) were recorded to assess the conduction properties and extent of denervation atrophy. The number of retrograde-labeled lumbar motor neurons identified by fluorescent dyes in the ipsilateral ventral horn and spinal ganglia were counted to assess the regeneration of axons. RESULTS: After 4 and 16 weeks, improvement of the sciatic function index of the sciatic nerve in group III was statistically greater than that of the negative control group, group I, and group II. At 16 weeks after grafting, obvious differences in the GMI were found among groups. Group III had a statistical increase in GMI compared with the negative control group, group I, and group II. The CMAP and NCV measurements showed comparable results at 16 weeks after reconstruction: group III had statistically better results compared with the negative control group, group I, and group II. Fluorescent dye analysis of the retrograde-labeled lumbar motoneurons in the ipsilateral ventral horn and spinal ganglia showed that more motor neurons in the ipsilateral ventral horns and spinal ganglia were labeled in group III than in the negative control group, group I, and group II at 16 weeks after the operation. All results consistently showed that when BMSCs and SCs were loaded together in an acellular nerve scaffold, functional recovery of the sciatic nerve was enhanced to the greatest degree among the 3 cell-treated groups; furthermore, its beneficial effect on sciatic injury regeneration was similar to the autograft group, although it never exceeded it. CONCLUSIONS: This study is a step forward in the search for an alternative to the nerve autograft because it showed that co-grafting of BMSCs and SCs into an acellular nerve scaffold enhanced sciatic nerve functional recovery in rats. Its beneficial effect on sciatic injury regeneration was similar to the autograft group, although it did not exceed it.

Time-specific microRNA changes during spinal motoneuron degeneration in adult rats following unilateral brachial plexus root avulsion: ipsilateral vs. contralateral changes.

BACKGROUND: Spinal root avulsion induces multiple pathophysiological events consisting of altered levels of specific genes and proteins related to inflammation, apoptosis, and oxidative stress, which collectively result in the death of the affected motoneurons. Recent studies have demonstrated that the gene changes involved in spinal cord injury can be regulated by microRNAs, which are a class of short non-coding RNA molecules that repress target mRNAs post-transcriptionally. With consideration for the time course of the avulsion-induced gene expression patterns within dying motoneurons, we employed microarray analysis to determine whether and how microRNAs are involved in the changes of gene expression induced by pathophysiological events in spinal cord motoneurons. RESULTS: The expression of a total of 3,361 miRNAs in the spinal cord of adult rats was identified. Unilateral root-avulsion resulted in significant alterations in miRNA expression. In the ipsilateral half compared to the contralateral half of the spinal cord, on the 3rd day after the injury, 55 miRNAs were upregulated, and 24 were downregulated, and on the 14th day after the injury, 36 miRNAs were upregulated, and 23 were downregulated. The upregulation of miR-146b-5p and miR-31a-3p and the downregulation of miR-324-3p and miR-484 were observed. Eleven of the miRNAs, including miR-21-5p, demonstrated a sustained increase; however, only miR-466c-3p presented a sustained decrease 3 and 14 days after the injury. More interestingly, 4 of the miRNAs, including miR-18a, were upregulated on the 3rd day but were downregulated on the 14th day after injury.Some of these miRNAs target inflammatory-response genes in the early stage of injury, and others target neurotransmitter transport genes in the intermediate stages of injury. The altered miRNA expression pattern suggests that the MAPK and calcium signaling pathways are consistently involved in the injury response. CONCLUSIONS: This analysis may facilitate the understanding of the time-specific altered expression of a large set of microRNAs in the spinal cord after brachial root avulsion.

Lithium enhances survival and regrowth of spinal motoneurons after ventral root avulsion.

BACKGROUND: During the clinical treatment of the brachial plexus root avulsion (BPRA), reimplantation surgery can not completely repair the motor function of the hand because the axonal growth velocity of the spinal motoneurons (MNs) is too slow to re-innervate the intrinsic hand muscles before muscle atrophy. Here, we investigated whether lithium can enhance the regenerative capacity of the spinal MNs in a rat model of BPRA. RESULTS: The avulsion and immediate reimplantation of the C7 and C8 ventral roots were performed and followed with daily intraperitoneal administration of a therapeutic concentrationof LiCl. After a 20 week long-term rehabilitation, the motor function recovery of the injured forepaw was studied by a grasping test. The survival and regeneration of MNs were checked by choline acetyltransferase (ChAT) immunofluorescence and by Fluoro-Gold (FG) retrograde labeling through the median and ulnar nerves of the ventral horn MNs. The number and diameter of the nerve fibers in the median nerve were assessed by toluidine blue staining. Our results showed that lithium plus reimplantation therapy resulted in a significantly higher grasping strength of the digits of the injured forepaw. Lithium plus reimplantation allowed 45.1% ± 8.11% of ChAT-positive MNs to survive the injury and increased the number and diameter of nerve fibers in the median nerve. The number of FG-labeled regenerative MNs was significantly elevated in all of the reimplantation animals. Our present data proved that lithium can enhance the regenerative capacity of spinal MNs. CONCLUSIONS: These results suggest that immediate administration of lithium could be used to assist reimplantation surgery in repairing BPRA injuries in clinical treatment.

Risk Factors of Serious Adverse Events for Geriatric Hip Fractures: Is it the Frailty or the Timing?

Objective: Preoperative frailty and surgical waiting times are associated with the occurrence of adverse outcomes in patients with hip fractures. Specifically, we aimed to investigate the influence of frailty status and surgical timing on the risk of serious adverse events during hospitalization. Methods: This study utilized an observational single cohort design and included patients aged ≥60 years with a primary diagnosis of hip fracture. Frailty was assessed using the chart-derived frailty index (CFI), which was calculated based on demographic and routine laboratory variables. The primary outcome of interest was the occurrence of in-hospital serious adverse events. A multivariate logistic regression model was utilized to examine the risk factors influencing outcomes. Results: The study included 427 participants, with a mean age of 80.28 ± 8.13 years and 64.2% of whom were female. Patients with high CFI have more comorbidities (P < .001), lower surgical rates (P = .002), and delayed surgical times (P = .033). A total of 239 patients (56.0%) experienced serious adverse events. The high CFI group had a significantly higher occurrence of serious adverse events compared to the low CFI group (73.4% vs 48.5%, P < .001). After adjusting for surgical timing and covariates, the multivariate logistic regression analysis revealed that high frailty significantly increased the risk for serious adverse events (OR = 2.47, 95% CI 1.398-4.412), infection (OR = 1.99, 95% CI 1.146-3.446), acute heart failure (OR = 3.37, 95% CI 1.607-7.045). However, the timing of surgery did not demonstrate any association with these outcomes. In addition, after adjusting for surgical factors, high CFI remains an independent risk factor for these complications. Conclusions: Frailty serves as a reliable predictor of the probability of encountering severe adverse events while hospitalized for elderly individuals with hip fractures. This method has the potential to pinpoint particular modifiable factors that necessitate intervention, whereas the impact of surgical timing remains uncertain and necessitates additional research.

BCR-ABL tyrosine kinase inhibitor pharmacophore model derived from a series of phenylaminopyrimidine-based (PAP) derivatives.

To reveal novel insights into the inhibition of BCR-ABL tyrosine kinase, pharmacophore mapping studies were performed for a series of phenylaminopyrimidine-based (PAP) derivatives, including imatinib (Gleevec). A seven-point pharmacophore model with one hydrophobic group (H), two hydrogen bond donors (D) and four aromatic rings (R) was developed using phase (pharmacophore alignment & scoring engine). The pharmacophore hypothesis yielded a statistically significant 3D-QSAR model, with a correlation coefficient of 0.886 and a survival score of 4.97 for training set molecules. The model showed excellent predictive power, with a correlation coefficient of Q(2)=0.768 for an external test set of ten molecules. The results obtained from our studies provide a valuable tool for designing new lead molecules with potent activity.

Effects of sevoflurane and propofol on cultured bone-marrow mesenchymal stem cells of rats.

OBJECTIVE: Bone marrow mesenchymal stem cell (BMSC) is a potentially effective vehicle for the cell and gene therapy in clinical disease treatment. We studied whether the most commonly used anesthetic drugs have negative effects on rat BMSCs in vitro. MATERIALS AND METHODS: The cultured BMSCs were treated with sevoflurane (in 1.7%, 2.3%, and 3%); propofol (5 µg/ml, 10 µg/ml and 20 µg/ml); or 2.3% sevoflurane plus 10 µg/ml propofol. After 4-hour treatment, the cultured BMSCs were prepared for MTT reduction assays and cell morphology observation. RESULTS: Compared to the controls, the 4-hour sevoflurane exposure resulted in decreased cell viability of BMSCs in a concentration-dependent manner; however, 1.7% sevoflurane did not reduce the cell viability. The 4-hour propofol treatment did not affect the cell viability; but combined usage of 2.3% sevoflurane and 10 µg/ml propofol decreased cell viability. In BMSCs treated with higher concentration of sevoflurane (1.7% and 2.3%) and combined usage of the two anesthetics, the cell became raritas with wizened cytoplasm and had fewer connections to each other of BMSCs. More than 2.3%, or 2.3% sevoflurane plus 10 µg/ ml propofol caused cytotoxicity to BMSCs. However, propofol up to 20 µg/ml did not harm the BMSCs. CONCLUSIONS: The study indicates that it is necessary to choose the right anesthesia during the BMSCs transplantation therapy.

Perceived professional benefits and their associated factors among Chinese registered nurses caring for women diagnosed with gynecological cancer.

PROPOSE: Registered nurses (RNs) are considered to be a major source of professional supportive care for women diagnosed with gynecological cancer (GC). This study described the level of perceived professional benefits and explored association between perceived professional benefits, sense of coherence (SOC), and coping strategies in Chinese RNs caring for women diagnosed with GC. METHOD: A cross-sectional survey was employed to collect data using the Nurses' Perceived Professional Benefits Questionnaire (NPPBQ), Sense of coherence scale (SOC-13), and Brief Coping Orientation to Problems Experienced (Brief COPE). The questionnaires were administered to 250 RNs in China. The correlations between NPPBQ, SOC-13, and Brief COPE were evaluated with Pearson's correlation coefficient. Multiple regression analysis was performed to assess the relative contribution of each possible factor in explaining variance in the increased NPPBQ. RESULTS: The total score for the NPPBQ was 142.4 (range 33.0-165.0). SOC, dysfunctional coping strategies, and problem-focused coping strategies were recognized as predictors of RNs' perceived professional benefit, while, emotion-focused coping strategies were not significantly associated with RNs' perceived professional benefits. CONCLUSIONS: The findings indicate that RNs who have high levels of SOC, dysfunctional coping strategies, and problem-focused coping strategies tend to experience more perceived professional benefit. These findings propose new perspectives for nursing managers to promote RNs' perceived professional benefit by helping RNs to find meaningfulness when caring for women diagnosed with GC, increasing RNs' communication skills to improve their relationship with patients, and training RNs to use coping strategies effectively.

Metformin inhibits ovarian granular cell pyroptosis through the miR-670-3p/NOX2/ROS pathway.

Recent studies have demonstrated that ovarian granular cells (OGCs) pyroptosis is present in the ovaries of polycystic ovary syndrome (PCOS) mice and that NLRP3 activation destroys follicular functions. Metformin has been shown to protect against PCOS by reducing insulin resistance in women, whereas its role in OGC pyroptosis is unknown. This study aimed to investigate the impact of metformin on OGC pyroptosis and the underlying mechanisms. The results showed that treating a human granulosa-like tumor cell line (KGN) with metformin significantly decreased LPS-induced expression of miR-670-3p, NOX2, NLRP3, ASC, cleaved caspase-1, and GSDMD-N. Cellular caspase-1 activity; ROS production; oxidative stress; and the secretion of IL-1ß, IL-6, IL-18, and TNF-α were also diminished. These effects were amplified by adding N-acetyl-L-cysteine (NAC), a pharmacological inhibitor of ROS. In contrast, metformin's anti-pyroptosis and anti-inflammatory effects were robustly ameliorated by NOX2 overexpression in KGN cells. Moreover, bioinformatic analyses, RT-PCR, and Western blotting showed that miR-670-3p could directly bind to the NOX2 (encoded by the CYBB gene in humans) 3'UTR and decrease NOX2 expression. Metformin-induced suppression of NOX2 expression, ROS production, oxidative stress, and pyroptosis was significantly alleviated by transfection with the miR-670-3p inhibitor. These findings suggest that metformin inhibits KGN cell pyroptosis via the miR-670-3p/NOX2/ROS pathway.

Donor-Derived Transmission of Scedosporiosis in Kidney Transplant Recipients from a Systemic lupus erythematosus donor.

Donor-derived infection (DDI) associated with Scedosporium spp is extremely rare, and results in a very poor prognosis. The present study reports a probable DDI due to Scedosporium boydii (S. boydii) from a donor with neuropsychiatric systemic lupus erythematosus. Two recipients developed Scedosporiosis after kidney transplantation from the same donor. Recipient 1 died of central nervous system infection due to S. boydii based on the clinical presentations, and the positive metagenomic next-generation sequencing (mNGS) and culture results for the cerebrospinal fluid. The other recipient with urinary tract obstruction due to S. boydii, which was identified through the positive culture and mNGS results of the removed stents, was successfully treated by stent replacement and voriconazole administration. Undiagnosed disseminated donor infection and the transmission of S. boydii should be given attention, particularly when the donor and recipients have primary immunodeficiency disease. The screening of donors and recipients for S. boydii using mNGS may be helpful in guiding antifungal prophylaxis and treatment recipients, due to its higher sensitivity and shorter diagnostic time relative to other traditional techniques.

LPA1 receptors in the lateral habenula regulate negative affective states associated with alcohol withdrawal.

The role of lysophosphatidic acid (LPA) signaling in psychiatric disorders and drug abuse is significant. LPA receptors are widely expressed in the central nervous system, including the lateral habenula (LHb). Recent studies suggest that LHb is involved in a negative emotional state during alcohol withdrawal, which can lead to relapse. The current study examines the role of LHb LPA signaling in the negative affective state associated with alcohol withdrawal. Adult male Long-Evans rats were trained to consume either alcohol or water for eight weeks. At 48 h of withdrawal, alcohol-drinking rats showed anxiety- and depression-like symptoms, along with a significant increase in LPA signaling and related neuronal activation molecules, including autotaxin (ATX, Enpp2), LPA receptor 1/3 (LPA1/3), ßCaMKII, and c-Fos. However, there was a decrease in lipid phosphate phosphatase-related protein type 4 (LPPR4) in the LHb. Intra-LHb infusion of the LPA1/3 receptor antagonist ki-16425 or PKC-γ inhibitor Go-6983 reduced the abnormal behaviors and elevated relapse-like ethanol drinking. It also normalized high LPA1/3 receptors and enhanced AMPA GluA1 phosphorylation in Ser831 and GluA1/GluA2 ratio. Conversely, selective activation of LPA1/3 receptors by intra-LHb infusion of 18:1 LPA induced negative affective states and upregulated ßCaMKII-AMPA receptor phosphorylation in Naive rats, which were reversed by pretreatment with intra-LHb Go-6983. Our findings suggest that disturbances in LPA signaling contribute to adverse affective disorders during alcohol withdrawal, likely through PKC-γ/ßCaMKII-linked glutamate signaling. Targeting LPA may therefore be beneficial for individuals suffering from alcohol use disorders.

Activation of phospholipase-Cγ and protein kinase C signal pathways helps the survival of spinal motoneurons injured by root avulsion.

The signaling transduction processes involved in avulsion-induced motoneuron (MN) death have not been elucidated. Using the brachial plexus root avulsion rat model, we showed that avulsion-activated phosphorylation of phospholipase-Cγ (PLCγ) and protein kinase C (PKC) occurred in injured spinal MNs within 72 h of injury. Moreover, some MNs positive for PLCγ and PKC are also positive for avulsion-induced neuronal nitric oxide synthase (nNOS). Inhibition of PLCγ/PKC signal pathway, either with PLCγ inhibitor, 1-[6-((17ß-3-methoxyestra-1,3,5(10)-trien-17-yl) amino)hexyl]-1H-pyrrole-2,5-dione, or with PLCγ siRNA augmented avulsion-induced MN death. 1-[6-((17ß-3-methoxyestra-1,3,5(10)-trien-17-yl) amino)hexyl]-1H-pyrrole-2,5-dione also inhibited PKC phosphorylation and exacerbated avulsion-induced reductions in the nNOS protein level in injured spinal segments. Moreover, activation of PLCγ/PKC signal pathway with PKC activator, phorbol-12-myristate-13-acetate, decreased avulsion-induced MN death. The temporal profile of PLCγ/PKC signaling appears to be crucial for the survival of spinal MNs after root avulsion. Our data suggest that PLCγ mediates, while PKC and nNOS are associated with, the avulsion-induced MN death in brachial plexus root avulsion.

Exploring the binding of BACE-1 inhibitors using comparative binding energy analysis (COMBINE).

BACKGROUND: The inhibition of the activity of ß-secretase (BACE-1) is a potentially important approach for the treatment of Alzheimer disease. To explore the mechanism of inhibition, we describe the use of 46 X-ray crystallographic BACE-1/inhibitor complexes to derive quantitative structure-activity relationship (QSAR) models. The inhibitors were aligned by superimposing 46 X-ray crystallographic BACE-1/inhibitor complexes, and gCOMBINE software was used to perform COMparative BINding Energy (COMBINE) analysis on these 46 minimized BACE-1/inhibitor complexes. The major advantage of the COMBINE analysis is that it can quantitatively extract key residues involved in binding the ligand and identify the nature of the interactions between the ligand and receptor. RESULTS: By considering the contributions of the protein residues to the electrostatic and van der Waals intermolecular interaction energies, two predictive and robust COMBINE models were developed: (i) the 3-PC distance-dependent dielectric constant model (built from a single X-ray crystal structure) with a q2 value of 0.74 and an SDEC value of 0.521; and (ii) the 5-PC sigmoidal electrostatic model (built from the actual complexes present in the Brookhaven Protein Data Bank) with a q2 value of 0.79 and an SDEC value of 0.41. CONCLUSIONS: These QSAR models and the information describing the inhibition provide useful insights into the design of novel inhibitors via the optimization of the interactions between ligands and those key residues of BACE-1.

[Study on the pathogenesis of stress myocardial injury].

OBJECTIVE: To investigate the pathogenesis of stress myocardial injury. METHODS: Thirty Wistar rats were randomly divided into three groups, with 10 rats in each group: normal control group, movement restriction and ice swimming stress group (rat movement was restricted 6 hours per day; beginning from 13th day rats were allowed to swim in ice water for 5 minutes, ice stress group), and endotoxin stress group [intraperitoneal injection of lipopolysaccharide (LPS) 10 mg/kg, LPS group]. The myocardial tissue was harvested, the pathological changes in myocardial was observed with light microscopy, and the changes in myocardial ultrastructure were observed with electron microscope. The levels of serum cardiac troponin I (cTnI) was determined by enzyme-linked immunosorbent assay (ELISA), apoptosis of myocardial cells was detected by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL), and the apoptotic index was calculated.The caspase-8 and caspase-3 expression in myocardial tissue were assessed by immunohistochemistry. The correlation between caspase and apoptotic index was analyzed. RESULTS: Compared with normal control group, in ice stress group and LPS group, myocardial tissue was found to be injured seriously in different degrees under light microscopy and electron microscopy; the content of cTnI (µg/L) in serum was significantly increased (0.63 ± 0.12, 0.74 ± 0.08 vs. 0.53 ± 0.03, P < 0.05 and P < 0.01); apoptosis index of myocardial tissue was significantly increased in different degrees [(7.91 ± 1.71)%, (12.94 ± 2.00)% vs. 0]; caspase-8 and caspase-3 expressions in the myocardium were increased (caspase-8 gray scale: 126.65 ± 3.13, 114.82 ± 8.67 vs. 156.99 ± 9.66; caspase-3 gray scale: 130.20 ± 2.96, 108.58 ± 5.72 vs. 160.51 ± 5.25, all P < 0.01). However, the above indexes in LPS group were significantly higher than those in ice stress group (P < 0.05 or P < 0.01). The correlation analysis showed that in ice stress group, positive correlation was found between caspase-8, caspase-3 and apoptotic index [r(1) = 0.914, P(1) = 0.002; r(2) = 0.929, P(2) = 0.001]; in LPS group, the positive correlation also exist between caspase-8, caspase-3 and apoptotic index [r(1) = 0.956, P(1) = 0.000; r(2) = 0.916, P(2) = 0.001]. CONCLUSION: Severe stress may produce stress injury of myocardium via increasing expression of caspase-8 and caspase-3 protein.

Pre-Clinical Medical Students' Use of Motivational and Cognitive Study Strategies During Anatomy Learning: A Three-Year Cross-Sectional Survey.

Medical students' motivation and study strategies are crucial in determining academic performance. This study aimed to assess the motivation and learning strategies of medical students as well as their association with performance in anatomy examinations. The Motivated Strategies for Learning Questionnaire, two focus group discussions, and students' current anatomy cumulative grade point average (cGPA) were used. Generally, the medical students strongly felt that anatomy is fundamental to the practice of medicine and surgery. This result was consistent with high task value scores of 5.99 ± 1.25. They were also driven by extrinsic goal orientation (5.59 ± 1.42) and intrinsic goal orientation (5.08 ± 1.26). Most medical students typically relied on elaboration (5.35 ± 1.25) ahead of other cognitive strategies namely rehearsal (5.30 ± 1.11), organization (5.15 ± 1.34), and lowest-rated critical thinking (4.77 ± 1.19). The students also relied on resource management strategies, effort regulation (5.15 ± 1.20) and time and study environment regulation (5.03 ± 1.03) more than the moderately scored peer learning (4.95 ± 1.50) and help-seeking (4.95 ± 1.09). In the focus group discussions, students reported that they often narrate or explain to each other what they would have read and understood from anatomy lectures, tutorials, and textbooks. They also bemoaned the lack of institutional support for stress burdens. The motivation and learning strategies subscales were not correlated with anatomy cGPA. Males were driven by extrinsic goals and experienced significantly higher levels of test anxiety than females (P < 0.05). Knowing the motivation and learning strategies students employ early in the medical curriculum can be leveraged to promote self-directed learning and academic achievement.