Visualization of Spatiotemporal Energy Dynamics of Hippocampal Neurons by Mass Spectrometry during a Kainate-Induced Seizure

We report the use of matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry combined with capillary electrophoresis (CE) mass spectrometry to visualize energy metabolism in the mouse hippocampus by imaging energy-related metabolites. We show the distribution patterns of ATP, ADP, and AMP in the hippocampus as well as changes in their amounts and distribution patterns in a murine model of limbic, kainate-induced seizure. As an acute response to kainate administration, we found massive and moderate reductions in ATP and ADP levels, respectively, but no significant changes in AMP levels—especially in cells of the CA3 layer. The results suggest the existence of CA3 neuron-selective energy metabolism at the anhydride bonds of ATP and ADP in the hippocampal neurons during seizure. In addition, metabolome analysis of energy synthesis pathways indicates accelerated glycolysis and possibly TCA cycle activity during seizure, presumably due to the depletion of ATP. Consistent with this result, the observed energy depletion significantly recovered up to 180 min after kainate administration. However, the recovery rate was remarkably low in part of the data-pixel population in the CA3 cell layer region, which likely reflects acute and CA3-selective neural death. Taken together, the present approach successfully revealed the spatiotemporal energy metabolism of the mouse hippocampus at a cellular resolution—both quantitatively and qualitatively. We aim to further elucidate various metabolic processes in the neural system

Abnormal phospholipids distribution in the prefrontal cortex from a patient with schizophrenia revealed by matrix-assisted laser desorption/ionization imaging mass spectrometry

Schizophrenia is one of the major psychiatric disorders, and lipids have focused on the important roles in this disorder. In fact, lipids related to various functions in the brain. Previous studies have indicated that phospholipids, particularly ones containing polyunsaturated fatty acyl residues, are deficient in postmortem brains from patients with schizophrenia. However, due to the difficulties in handling human postmortem brains, particularly the large size and complex structures of the human brain, there is little agreement regarding the qualitative and quantitative abnormalities of phospholipids in brains from patients with schizophrenia, particularly if corresponding brain regions are not used. In this study, to overcome these problems, we employed matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS), enabling direct microregion analysis of phospholipids in the postmortem brain of a patient with schizophrenia via brain sections prepared on glass slides. With integration of traditional histochemical examination, we could analyze regions of interest in the brain at the micrometric level. We found abnormal phospholipid distributions within internal brain structures, namely, the frontal cortex and occipital cortex. IMS revealed abnormal distributions of phosphatidylcholine molecular species particularly in the cortical layer of frontal cortex region. In addition, the combined use of liquid chromatography/electrospray ionization tandem mass spectrometry strengthened the capability for identification of numerous lipid molecular species. Our results are expected to further elucidate various metabolic processes in the neural system

Cthrc1 Is a Positive Regulator of Osteoblastic Bone Formation

Bone mass is maintained by continuous remodeling through repeated cycles of bone resorption by osteoclasts and bone formation by osteoblasts. This remodeling process is regulated by many systemic and local factors.We identified collagen triple helix repeat containing-1 (Cthrc1) as a downstream target of bone morphogenetic protein-2 (BMP2) in osteochondroprogenitor-like cells by PCR-based suppression subtractive hybridization followed by differential hybridization, and found that Cthrc1 was expressed in bone tissues in vivo. To investigate the role of Cthrc1 in bone, we generated Cthrc1-null mice and transgenic mice which overexpress Cthrc1 in osteoblasts (Cthrc1 transgenic mice). Microcomputed tomography (micro-CT) and bone histomorphometry analyses showed that Cthrc1-null mice displayed low bone mass as a result of decreased osteoblastic bone formation, whereas Cthrc1 transgenic mice displayed high bone mass by increase in osteoblastic bone formation. Osteoblast number was decreased in Cthrc1-null mice, and increased in Cthrc1 transgenic mice, respectively, while osteoclast number had no change in both mutant mice. In vitro, colony-forming unit (CFU) assays in bone marrow cells harvested from Cthrc1-null mice or Cthrc1 transgenic mice revealed that Cthrc1 stimulated differentiation and mineralization of osteoprogenitor cells. Expression levels of osteoblast specific genes, ALP, Col1a1, and Osteocalcin, in primary osteoblasts were decreased in Cthrc1-null mice and increased in Cthrc1 transgenic mice, respectively. Furthermore, BrdU incorporation assays showed that Cthrc1 accelerated osteoblast proliferation in vitro and in vivo. In addition, overexpression of Cthrc1 in the transgenic mice attenuated ovariectomy-induced bone loss.Our results indicate that Cthrc1 increases bone mass as a positive regulator of osteoblastic bone formation and offers an anabolic approach for the treatment of osteoporosis

The Impact of COVID-19 Pandemic on Spine Surgeons Worldwide : A One Year Prospective Comparative Study

Study Design: Survey Objective: In March of 2020, an original study by Louie et al investigated the impact of COVID-19 on 902 spine surgeons internationally. Since then, due to varying government responses and public health initiatives to the pandemic, individual countries and regions of the world have been affected differently. Therefore, this follow-up study aimed to assess how the COVID-19 impact on spine surgeons has changed 1 year later. Methods: A repeat, multi-dimensional, 90-item survey written in English was distributed to spine surgeons worldwide via email to the AO Spine membership who agreed to receive surveys. Questions were categorized into the following domains: demographics, COVID-19 observations, preparedness, personal impact, patient care, and future perceptions. Results: Basic respondent demographics, such as gender, age, home demographics, medical comorbidities, practice type, and years since training completion, were similar to those of the original 2020 survey. Significant differences between groups included reasons for COVID testing, opinions of media coverage, hospital unemployment, likelihood to be performing elective surgery, percentage of cases cancelled, percentage of personal income, sick leave, personal time allocation, stress coping mechanisms, and the belief that future guidelines were needed (P<.05). Conclusion: Compared to baseline results collected at the beginning of the COVID-19 pandemic in 2020, significant differences in various domains related to COVID-19 perceptions, hospital preparedness, practice impact, personal impact, and future perceptions have developed. Follow-up assessment of spine surgeons has further indicated that telemedicine and virtual education are mainstays. Such findings may help to inform and manage expectations and responses to any future outbreaks.publishedVersionPeer reviewe

Perioperative Anticoagulation Management in Spine Surgery: Initial Findings From the AO Spine Anticoagulation Global Survey.

STUDY DESIGN: Cross-sectional, international survey. OBJECTIVES: This study addressed the global perspectives concerning perioperative use of pharmacologic thromboprophylaxis during spine surgery along with its risks and benefits. METHODS: A questionnaire was designed and implemented by expert members in the AO Spine community. The survey was distributed to AO Spine\u27s spine surgeon members (N = 3805). Data included surgeon demographic information, type and region of practice, anticoagulation principles, different patient scenarios, and comorbidities. Results: A total of 316 (8.3% response rate) spine surgeons completed the survey, representing 64 different countries. Completed surveys were primarily from Europe (31.7%), South/Latin America (19.9%), and Asia (18.4%). Surgeons tended to be 35 to 44 years old (42.1%), fellowship-trained (74.7%), and orthopedic surgeons (65.5%) from academic institutions (39.6%). Most surgeons (70.3%) used routine anticoagulation risk stratification, irrespective of geographic location. However, significant differences were seen between continents with anticoagulation initiation and cessation methodology. Specifically, the length of a procedure (P = .036) and patient body mass index (P = .008) were perceived differently when deciding to begin anticoagulation, while the importance of medical clearance (P \u3c .001) and reference to literature (P = .035) differed during cessation. For specific techniques, most providers noted use of mobilization, low-molecular-weight heparin, and mechanical prophylaxis beginning on postoperative 0 to 1 days. Conversely, bridging regimens were bimodal in distribution, with providers electing anticoagulant initiation on postoperative 0 to 1 days or days 5-6. CONCLUSION: This survey highlights the heterogeneity of spine care and accentuates geographical variations. Furthermore, it identifies the difficulty in providing consistent perioperative anticoagulation recommendations to patients, as there remains no widely accepted, definitive literature of evidence or guidelines

ACC2 Is Expressed at High Levels Human White Adipose and Has an Isoform with a Novel N-Terminus

Acetyl-CoA carboxylases ACC1 and ACC2 catalyze the carboxylation of acetyl-CoA to malonyl-CoA, regulating fatty-acid synthesis and oxidation, and are potential targets for treatment of metabolic syndrome. Expression of ACC1 in rodent lipogenic tissues and ACC2 in rodent oxidative tissues, coupled with the predicted localization of ACC2 to the mitochondrial membrane, have suggested separate functional roles for ACC1 in lipogenesis and ACC2 in fatty acid oxidation. We find, however, that human adipose tissue, unlike rodent adipose, expresses more ACC2 mRNA relative to the oxidative tissues muscle and heart. Human adipose, along with human liver, expresses more ACC2 than ACC1. Using RT-PCR, real-time PCR, and immunoprecipitation we report a novel isoform of ACC2 (ACC2.v2) that is expressed at significant levels in human adipose. The protein generated by this isoform has enzymatic activity, is endogenously expressed in adipose, and lacks the N-terminal sequence. Both ACC2 isoforms are capable of de novo lipogenesis, suggesting that ACC2, in addition to ACC1, may play a role in lipogenesis. The results demonstrate a significant difference in ACC expression between human and rodents, which may introduce difficulties for the use of rodent models for development of ACC inhibitors

Factors Affecting the Decision to Initiate Anticoagulation After Spine Surgery: Findings From the AOSpine Anticoagulation Global Initiative

STUDY DESIGN: Cross-sectional, international survey. OBJECTIVES: To identify factors influencing pharmacologic anticoagulation initiation after spine surgery based on the AOSpine Anticoagulation Global Survey. METHODS: This survey was distributed to the international membership of AOSpine (n = 3805). A Likert-type scale described grade practice-specific factors on a scale from low (1) to high (5) importance, and patient-specific factors a scale from low (0) to high (3) importance. Analysis was performed to determine which factors were significant in the decision making surrounding the initiation of pharmacologic anticoagulation. RESULTS: A total of 316 spine surgeons from 64 countries completed the survey. In terms of practice-specific factors considered to initiate treatment, expert opinion was graded the highest (mean grade ± SD = 3.2 ± 1.3), followed by fellowship training (3.2 ± 1.3). Conversely, previous studies (2.7 ± 1.2) and unspecified guidelines were considered least important (2.6 ± 1.6). Patient body mass index (2.0 ± 1.0) and postoperative mobilization (2.3 ± 1.0) were deemed most important and graded highly overall. Those who rated estimated blood loss with greater importance in anticoagulation initiation decision making were more likely to administer thromboprophylaxis at later times (hazard ratio [HR] = 0.68-0.71), while those who rated drain output with greater importance were likely to administer thromboprophylaxis at earlier times (HR = 1.32-1.43). CONCLUSION: Among our global cohort of spine surgeons, certain patient factors (ie, patient mobilization and body mass index) and practice-specific factors (ie, expert opinion and fellowship training) were considered to be most important when considering anticoagulation start times

The Impact of Modic Changes on Preoperative Symptoms and Clinical Outcomes in Anterior Cervical Discectomy and Fusion Patients

Objective To assess the impact of Modic changes (MC) on preoperative symptoms, and postoperative outcomes in anterior cervical discectomy and fusion (ACDF) patients. Methods We performed a retrospective study of prospectively collected data of ACDF patients at a single institution. Preoperative magnetic resonance imagings were used to assess the presence of MC. MC were stratified by type and location, and compared to patients without MC. Associations with symptoms, patient-reported measures, and surgical outcomes were assessed. Results A total of 861 patients were included, with 356 patients with MC (41.3%). MC more frequently occurred at C5–6 (15.1%), and type II was the most common type (61.2%). MC were associated with advanced age (p < 0.001), more levels fused (p < 0.001), a longer duration of symptoms, but not with specific symptoms. MC at C7–T1 resulted in higher postoperative disability (p < 0.001), but did not increase risk of adjacent segment degeneration or reoperation. Conclusion This study is the first to systematically examine the impact of cervical MC, stratified by type and location, on outcomes in ACDF patients. Patients with MC were generally older, required larger fusions, and had longer duration of preoperative symptoms. While MC may not affect specific outcomes following ACDF, they may indicate a more debilitating preoperative state for patients

The Impact of COVID-19 Pandemic on Spine Surgeons Worldwide

Study Design: Cross-sectional, international survey. Objectives: The current study addressed the multi-dimensional impact of COVID-19 upon healthcare professionals, particularly spine surgeons, worldwide. Secondly, it aimed to identify geographical variations and similarities. Methods: A multi-dimensional survey was distributed to surgeons worldwide. Questions were categorized into domains: demographics, COVID-19 observations, preparedness, personal impact, patient care, and future perceptions. Results: 902 spine surgeons representing 7 global regions completed the survey. 36.8% reported co-morbidities. Of those that underwent viral testing, 15.8% tested positive for COVID-19, and testing likelihood was region-dependent; however, 7.2% would not disclose their infection to their patients. Family health concerns were greatest stressor globally (76.0%), with anxiety levels moderately high. Loss of income, clinical practice and current surgical management were region-dependent, whereby 50.4% indicated personal-protective-equipment were not adequate. 82.3% envisioned a change in their clinical practice as a result of COVID-19. More than 33% of clinical practice was via telemedicine. Research output and teaching/training impact was similar globally. 96.9% were interested in online medical education. 94.7% expressed a need for formal, international guidelines to manage COVID-19 patients. Conclusions: In this first, international study to assess the impact of COVID-19 on surgeons worldwide, we identified overall/regional variations and infection rate. The study raises awareness of the needs and challenges of surgeons that will serve as the foundation to establish interventions and guidelines to face future public health crises.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]