Cord Specimens Research Articles

Seeding activity of human superoxide dismutase 1 aggregates in familial and sporadic amyotrophic lateral sclerosis postmortem neural tissues by real-time quaking-induced conversion

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neurodegenerative disease with average lifespan of 2–5 years after diagnosis. The identification of novel prognostic and pharmacodynamic biomarkers are needed to facilitate therapeutic development. Metalloprotein human superoxide dismutase 1 (SOD1) is known to accumulate and form aggregates in patient neural tissue with familial ALS linked to mutations in their SOD1 gene. Aggregates of SOD1 have also been detected in other forms of ALS, including the sporadic form and the most common familial form linked to abnormal hexanucleotide repeat expansions in the Chromosome 9 open reading frame 72 (C9ORF72) gene. Here, we report the development of a real-time quaking-induced conversion (RT-QuIC) seed amplification assay using a recombinant human SOD1 substrate to measure SOD1 seeding activity in postmortem spinal cord and motor cortex tissue from persons with different ALS etiologies. Our SOD1 RT-QuIC assay detected SOD1 seeds in motor cortex and spinal cord dilutions down to 10–5. Importantly, we detected SOD1 seeding activity in specimens from both sporadic and familial ALS cases, with the latter having mutations in either their SOD1 or C9ORF72 genes. Analyses of RT-QuIC parameters indicated similar lag phases in spinal cords of sporadic and familial ALS patients, but higher ThT fluorescence maxima by SOD1 familial ALS specimens and sporadic ALS thoracic cord specimens. For a subset of sporadic ALS patients, motor cortex and spinal cords were examined, with seeding activity in both anatomical regions. Our results suggest SOD1 seeds are in ALS patient neural tissues not linked to SOD1 mutation, suggesting that SOD1 seeding activity may be a promising biomarker, particularly in sporadic ALS cases for whom genetic testing is uninformative.

LINC complex alterations are a key feature of sporadic and familial ALS/FTD

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder that primarily affects motor neurons, leading to progressive muscle weakness and loss of voluntary muscle control. While the exact cause of ALS is not fully understood, emerging research suggests that dysfunction of the nuclear envelope (NE) may contribute to disease pathogenesis and progression. The NE plays a role in ALS through several mechanisms, including nuclear pore defects, nucleocytoplasmic transport impairment, accumulation of mislocalized proteins, and nuclear morphology abnormalities. The LINC complex is the second biggest multi-protein complex in the NE and consists of the SUN1/2 proteins spanning the inner nuclear membrane and Nesprin proteins embedded in the outer membrane. The LINC complex, by interacting with both the nuclear lamina and the cytoskeleton, transmits mechanical forces to the nucleus regulating its morphology and functional homeostasis. In this study we show extensive alterations to the LINC complex in motor and cortical iPSC-derived neurons and spinal cord organoids carrying the ALS causative mutation in the C9ORF72 gene (C9). Importantly, we show that such alterations are present in vivo in a cohort of sporadic ALS and C9-ALS postmortem spinal cord and motor cortex specimens. We also found that LINC complex disruption strongly correlated with nuclear morphological alterations occurring in ALS neurons, independently of TDP43 mislocalization. Altogether, our data establish morphological and functional alterations to the LINC complex as important events in ALS pathogenic cascade, making this pathway a possible target for both biomarker and therapy development.

Intravenous Administration of Mesenchymal Stem Cell-Derived Exosome Alleviates Spinal Cord Injury by Regulating Neutrophil Extracellular Trap Formation through Exosomal miR-125a-3p.

Spinal cord injury (SCI) leads to devastating sequelae, demanding effective treatments. Recent advancements have unveiled the role of neutrophil extracellular traps (NETs) produced by infiltrated neutrophils in exacerbating secondary inflammation after SCI, making it a potential target for treatment intervention. Previous research has established that intravenous administration of stem cell-derived exosomes can mitigate injuries. While stem cell-derived exosomes have demonstrated the ability to modulate microglial reactions and enhance blood-brain barrier integrity, their impact on neutrophil deactivation, especially in the context of NETs, remains poorly understood. This study aims to investigate the effects of intravenous administration of MSC-derived exosomes, with a specific focus on NET formation, and to elucidate the associated molecular mechanisms. Exosomes were isolated from the cell supernatants of amnion-derived mesenchymal stem cells using the ultracentrifugation method. Spinal cord injuries were induced in Sprague-Dawley rats (9 weeks old) using a clip injury model, and 100 μg of exosomes in 1 mL of PBS or PBS alone were intravenously administered 24 h post-injury. Motor function was assessed serially for up to 28 days following the injury. On Day 3 and Day 28, spinal cord specimens were analyzed to evaluate the extent of injury and the formation of NETs. Flow cytometry was employed to examine the formation of circulating neutrophil NETs. Exogenous miRNA was electroporated into neutrophil to evaluate the effect of inflammatory NET formation. Finally, the biodistribution of exosomes was assessed using 64Cu-labeled exosomes in animal positron emission tomography (PET). Rats treated with exosomes exhibited a substantial improvement in motor function recovery and a reduction in injury size. Notably, there was a significant decrease in neutrophil infiltration and NET formation within the spinal cord, as well as a reduction in neutrophils forming NETs in the circulation. In vitro investigations indicated that exosomes accumulated in the vicinity of the nuclei of activated neutrophils, and neutrophils electroporated with the miR-125a-3p mimic exhibited a significantly diminished NET formation, while miR-125a-3p inhibitor reversed the effect. PET studies revealed that, although the majority of the transplanted exosomes were sequestered in the liver and spleen, a notably high quantity of exosomes was detected in the damaged spinal cord when compared to normal rats. MSC-derived exosomes play a pivotal role in alleviating spinal cord injury, in part through the deactivation of NET formation via miR-125a-3p.

Topiramate affords neuroprotection in diabetic neuropathy model via downregulating spinal GFAP/inflammatory burden and improving neurofilament production

The current study aimed to test the neuroprotective action of topiramate in mouse peripheral diabetic neuropathy (DN) and explored some mechanisms underlying this action. Mice were assigned as vehicle group, DN group, DN + topiramate 10-mg/kg and DN + topiramate 30-mg/kg. Mice were tested for allodynia and hyperalgesia and then spinal cord and sciatic nerves specimens were examined microscopically and neurofilament heavy chain (NEFH) immunostaining was performed. Results indicated that DN mice had lower the hotplate latency time (0.46-fold of latency to licking) and lower von-Frey test pain threshold (0.6-fold of filament size) while treatment with topiramate increased these values significantly. Sciatic nerves from DN control mice showed axonal degeneration while spinal cords showed elevated GFAP (5.6-fold) and inflammatory cytokines (∼3- to 4-fold) but lower plasticity as indicated by GAP-43 (0.25-fold). Topiramate produced neuroprotection and suppressed spinal cord GFAP/inflammation but enhanced GAP-43. This study reinforces topiramate as neuroprotection and explained some mechanisms included in alleviating neuropathy.

Cerium Oxide Nanoparticles Ameliorate Oxidative Stress, Inflammation, and Pain Behavior in Neuropathic Rats.

Neuropathic pain originating from a dysfunction in the nervous system is often intractable and chronic. Recently, several studies using nanoparticles suggested a new way to control neuropathic pain. This study intended to explore the potential neuroprotective effect of Cerium Oxide Nanoparticles (CNPs) synthesized by pullulan in neuropathic pain in rats. On the right common sciatic nerve of male Wistar rats, the chronic constriction injury (CCI) procedure was used to establish a neuropathic pain model. CNPs were injected into the caudal vein of the rat. Behavioral methods were used to detect mechanical allodynia, cold allodynia, and thermal hyperalgesia in rats. Besides, inflammation factors, including tumor necrosis factor (TNF)-α, interleukin (IL)-1β, nitric oxide (NO), and markers of oxidative stress, including Malondialdehyde (MDA) and total thiol, were measured in the spinal cord segment of rats. In rats with CCI, mechanical allodynia, cold allodynia, and thermal hyperalgesia developed, which improved when the rats were administered CNPs. Spinal cord specimens of CCI rats had elevated inflammation and oxidative stress status (↑IL-1β, ↑TNF-α, ↑NO, ↑MDA) and decreased antioxidative levels (↓total thiol). As a result of CNPs treatment, these changes were reversed in the spinal cord specimens. CNPs alleviate neuropathic pain by exhibiting antioxidative and anti-inflammatory activities.

The Dominant Anterior Thoracic Artery of the Spinal Cord.

Dominant radiculomedullary arteries such as the artery of lumbar enlargement and the artery of cervical enlargement are well-documented. However, variability exists as to the size, number, and location of other radiculomedullary arteries contributing supply to the anterior spinal artery. The aim of this anatomic study was to document the prevalence and characteristics of the dominant anterior thoracic artery in cadaveric specimens. Microsurgical dissection of cadaveric human spinal cord specimens (n = 50) was conducted. The artery of lumbar enlargement was injected with colored latex until the small-caliber arterial vessels were filled. The dominant anterior thoracic artery was identified, injected, and filled with diluted industrial paint. The course, diameter, and location of the dominant anterior thoracic artery, artery of lumbar enlargement, and artery of cervical enlargement were documented. The artery of lumbar enlargement was identified between T3 and L2 in all 50 specimens (100%), and the artery of cervical enlargement was identified in 84% of specimens (42/50). At least 1 dominant anterior thoracic artery distinct from the artery of lumbar enlargement and the artery of cervical enlargement was identified between T1 and T11 in 47 of the 50 specimens (94%). The most frequent origin of the dominant anterior thoracic artery was at the level of T4 on the left. The average size of the dominant anterior thoracic artery was 0.446 mm (range, 0.300-0.759 mm on the left and 0.270-0.569 mm on the right). A dominant anterior thoracic artery is present in 94% of individuals. Variations of the arterial supply to the anterior thoracic cord are of great importance due to their implications for ischemic events as well as surgical and endovascular procedures.

Effects of Capparis Spinosa extract on the neuropathic pain induced by chronic constriction injury in rats.

Neuropathic pain, a chronic pain condition, puts a considerable burden on its patients. However, different pathophysiological characteristics of neuropathic pain make the current treatment medications insufficient in controlling pain. Identifying treatment effects with Capparis Spinosa hydro-alcoholic extract in an animal model of neuropathic pain. Liquid chromatography-mass spectrometry (LC-MS) was used to identify the components of C. Spinosa hydro-alcoholic extract. To establish a neuropathic pain model, adult male Wistar rats underwent chronic constriction injury (CCI) surgery in their left sciatic nerve. Male wistar rats were divided into four groups: CCI, Sham, CCI with C. Spinosa (100mg/kg), and CCI with C. Spinosa (200mg/kg). Rats were treated with a hydro-alcoholic extract from aerial parts of the C. Spinosa (orally, daily) starting from CCI induction until 14 days after. Behavioral tests (mechanical allodynia, cold allodynia, and thermal hyperalgesia) and biochemical tests (IL-1β, TNF-α, MDA, and total thiol) were taken from animals. The LC-MS analysis identified 22 compounds in C. Spinosa extract with the predominance of flavonoids. CCI produced a significant (P < 0.001) increase allodynia (mechanical and cold) and thermal hyperalgesia in comparison with sham group. Oral administration of C. Spinosa significantly (P < 0.05) ameliorated CCI-induced nociceptive pain compared with CCI group. Spinal cord specimens of CCI rats had significant (P < 0.05) elevated inflammation status (↑IL-1β, ↑TNF-α), and significant (P < 0.05) decreased antioxidative status (↑MDA, ↓total thiol) in comparison with the sham group. These changes were reversed following C. Spinosa treatment. C. Spinosa alleviates neuropathic pain by exhibiting antioxidative and anti-inflammatory effects. The responsible components for these effects are possibly the flavonoid compounds in C. Spinosa extract.

Eucommia ulmoides extract alleviated spinal cord injury in rats by inhibiting endoplasmic reticulum stress and oxidative stress

Spinal cord injury (SCI) is the major cause of severe disability worldwide, which leads to neuron death, neuronal degeneration, and functional changes in the spinal cord. Eucommia ulmoides extract (EUE) is composed of multiple iridoids and phenols and possesses anti-oxidative and anti-inflammatory effects in various pathologies. This study aims to evaluate the effects of EUE on SCI and the underlying mechanisms. Male adult Sprague-Dawley rats (250–280 g) were applied to mimic SCI in vivo. Western blot and ELISA kits assessed the expressions of apoptosis, oxidative stress, and endoplasmic reticulum stress (ER stress)-relevant proteins. The apoptosis rate of neurons in spinal cord specimens was measured by TUNEL assay. Finally, our data indicated that EUE inhibited SCI-induced apoptosis, oxidative stress, and ER stress through the suppression of mitogen-activated protein kinase (MAPK) pathway. Our data manifest EUE as a potential therapeutic target in SCI.

Improvement of Umbilical Cord Blood Gas Analysis with Implementation of Clot Catchers.

Umbilical cord blood gas testing is a key component of objective pre- and perinatal evaluation of fetal acid base status to determine presence of intrapartum asphyxia and risk of neonatal encephalopathy. Heparinized cord blood is more likely to form small clots than other blood sources, which can interfere with, or preclude, sample analysis. Cord blood samples are irreplaceable and cannot be recollected, thereby compromising clinical decision-making when analysis is not possible. We evaluated processes to prevent excessive rates of cord blood clotting and quantified their impact on successful testing of blood gas specimens. Verified result and cancellation data were obtained retrospectively from the laboratory information system. Clot catchers were evaluated using noncord remnant specimens. Collection syringes were compared via collection from remnant cord sections. Prior to implementation of any interventions, retrospective analysis indicated a cancellation rate of 18.6% for umbilical cord blood gas specimens (arterial and venous) and 0.7% for noncord blood arterial and venous samples. Clot catchers were validated for clinical use, with a bias of <±4% for all analytes. After clot catchers were implemented for all cord specimens, cancellation rate decreased approximately 5-fold in the first month and remained <5% a year after implementation. A limited comparison of two heparin syringe types revealed a small difference in the overall rate of specimen clotting. Implementation of clot catchers was acceptable for analysis of cord blood samples, and when implemented resulted in a sustained 5-fold decrease in the rate of cord blood gas order cancellation.

Dynamic induction of the myelin-associated growth inhibitor Nogo-A in perilesional plasticity regions after human spinal cord injury.

The myelin-associated inhibitor Nogo-A (Reticulon 4, RTN4) restricts axonal outgrowth, plasticity, and neural circuitry formation in experimental models of spinal cord injury (SCI) and is targeted in clinical interventions starting treatment within 4 weeks post-SCI. Specifically, Nogo-A expressed by oligodendroglia restricts compensatory neurite sprouting. To interrogate the hypothesis of an inducible, lesion reactive Nogo-A expression over time, we analyzed the spatiotemporal Nogo-A expression at the spinal lesion core (region of tissue necrosis and axonal damage/pruning) and perilesional rim (region of plasticity formation). Spinal cord specimens of SCI subjects (n=22) were compared to neuropathologically unaltered controls (n=9). Nogo-A expression was investigated ranging from acute (0-3 days), early subacute (4-21 days), late subacute (22-90 days) to early chronic-chronic (91 days to 1.5 years after SCI) stages after SCI. Nogo-A expression in controls is confined to motoneurons in the anterior horn and to oligodendrocytes in gray and white matter. After SCI, the number of Nogo-A+ and TPPP/p25+ oligodendrocytes (i) inclined at the organizing perilesional rim specifically, (ii) increased further over time, and (iii) peaked at chronic stages after SCI. By contrast, at the lesion core, the number of Nogo-A+ and TPPP/p25+ oligodendrocytes did not increase. Increasing numbers of Nogo-A+ oligodendrocytes coincided with oligodendrogenesis corroborated by Nogo-A coexpression of Ki67+ , TPPP/p25+ proliferating oligodendrocytes. Nogo-A oligodendrocyte expression emerges at perilesional (plasticity) regions over time and suggests an extended therapeutical window for anti-Nogo-A pathway targeting interventions beyond 4 weeks in patients after SCI.

Efficiency of transplacental transfer of respiratory syncytial virus (RSV) specific antibodies among pregnant women in Kenya.

Background: Maternal immunisation to boost respiratory syncytial virus (RSV) antibodies in pregnant women, is a strategy being considered to enhance infant protection from severe RSV associated disease. However, little is known about the efficiency of transplacental transfer of RSV-specific antibodies in a setting with a high burden of malaria and HIV, to guide the implementation of such a vaccination program. Methods: Using a plaque reduction neutralization assay, we screened 400 pairs of cord and maternal serum specimens from pregnant women for RSV-specific antibodies. Participants were pregnant women of two surveillance cohorts: 200 participants from a hospital cohort in Kilifi, Coastal Kenya and 200 participants from a surveillance cohort in Siaya, Western Kenya. Transplacental transfer efficiency was determined by the cord to maternal titre ratio (CMTR). Logistic regression was used to determine independent predictors of impaired transplacental transfer of RSV-specific antibodies. Results: A total of 800 samples were screened from the 400 participants. At enrollment the median age was 25 years (Interquartile range (IQR): 21-31). Overall, transplacental transfer was efficient and did not differ between Kilifi and Siaya cohort (1.02 vs. 1.02; p=0.946) but was significantly reduced among HIV-infected mothers compared to HIV-uninfected mothers (mean CMTR: 0.98 vs 1.03; p=0.015). Prematurity <33 weeks gestation (Odds ratio [OR]: 0.23, 95% confidence interval [CI] 0.06-0.85; p=0.028), low birth weight <2.5 kgs (OR: 0.25, 95% CI: 0.07-0.94; p=0.041) and HIV infection (OR: 0.47, 95% CI:0.23-0.98; p=0.045) reduced efficiency of transplacental transfer among these women. Conclusions: Transplacental transfer of RSV-specific antibodies among pregnant women in Kenya is efficient. A consideration to integrate other preventive interventions with maternal RSV vaccination targeting infants born premature (<33 weeks gestation), with low birth weight <2.5 kgs, or HIV-infected mothers is likely to improve vaccine outcomes in this setting.

Efficiency of transplacental transfer of respiratory syncytial virus (RSV) specific antibodies among pregnant women in Kenya

Background: Maternal immunisation to boost respiratory syncytial virus (RSV) antibodies in pregnant women, is a strategy being considered to enhance infant protection from severe RSV associated disease. However, little is known about the efficiency of transplacental transfer of RSV-specific antibodies in a setting with a high burden of malaria and HIV, to guide the implementation of such a vaccination program. Methods: Using a plaque reduction neutralization assay, we screened 400 pairs of cord and maternal serum specimens from pregnant women for RSV-specific antibodies. Participants were pregnant women of two surveillance cohorts: 200 participants from a hospital cohort in Kilifi, Coastal Kenya and 200 participants from a surveillance cohort in Siaya, Western Kenya. Transplacental transfer efficiency was determined by the cord to maternal titre ratio (CMTR). Logistic regression was used to determine independent predictors of impaired transplacental transfer of RSV-specific antibodies. Results: A total of 800 samples were screened from the 400 participants. At enrollment the median age was 25 years (Interquartile range (IQR): 21-31). Overall, transplacental transfer was efficient and did not differ between Kilifi and Siaya cohort (1.02 vs. 1.02; p=0.946) but was significantly reduced among HIV-infected mothers compared to HIV-uninfected mothers (mean CMTR: 0.98 vs 1.03; p=0.015). Prematurity <33 weeks gestation (Odds ratio [OR]: 0.23, 95% confidence interval [CI] 0.06–0.85; p=0.028), low birth weight <2.5 kgs (OR: 0.25, 95% CI: 0.07–0.94; p=0.041) and HIV infection (OR: 0.47, 95% CI:0.23-0.98; p=0.045) reduced efficiency of transplacental transfer among these women. Conclusions: Transplacental transfer of RSV-specific antibodies among pregnant women in Kenya is efficient. A consideration to integrate other preventive interventions with maternal RSV vaccination targeting infants born premature (<33 weeks gestation), with low birth weight <2.5 kgs, or HIV-infected mothers is likely to improve vaccine outcomes in this setting.

Efficiency of transplacental transfer of respiratory syncytial virus (RSV) specific antibodies among pregnant women in Kenya

Background: Maternal immunisation to boost respiratory syncytial virus (RSV) antibodies in pregnant women, is a strategy being considered to enhance infant protection from severe RSV associated disease. However, little is known about the efficiency of transplacental transfer of RSV-specific antibodies in a setting with a high burden of malaria and HIV, to guide the implementation of such a vaccination program. Methods: Using a plaque reduction neutralization assay, we screened 400 pairs of cord and maternal serum specimens from pregnant women for RSV-specific antibodies. Participants were pregnant women of two surveillance cohorts: 200 participants from a hospital cohort in Kilifi, Coastal Kenya and 200 participants from a surveillance cohort in Siaya, Western Kenya. Transplacental transfer efficiency was determined by the cord to maternal transfer ratio (CMTR). Logistic regression was used to determine independent predictors of impaired transplacental transfer of RSV-specific antibodies. Results: A total of 800 samples were screened from the 400 participants. At enrollment the median age was 25 years (Interquartile range (IQR): 21-31). Overall, transplacental transfer was efficient and did not differ between Kilifi and Siaya cohort (1.02 vs. 1.02; p=0.946) but was significantly reduced among HIV-infected mothers compared to HIV-uninfected mothers (mean CMTR: 0.98 vs 1.03; p=0.015). Prematurity &lt;33 weeks gestation (Odds ratio [OR]: 0.23, 95% confidence interval [CI] 0.06–0.85; p=0.028), low birth weight &lt;2.5 kgs (OR: 0.25, 95% CI: 0.07–0.94; p=0.041) and HIV infection (OR: 0.47, 95% CI:0.23-0.98; p=0.045) reduced efficiency of transplacental transfer among these women. Conclusions: Transplacental transfer of RSV-specific antibodies among pregnant women in Kenya is efficient. A consideration to integrate other preventive interventions with maternal RSV vaccination targeting infants born premature (&lt;33 weeks gestation), with low birth weight &lt;2.5 kgs, or HIV-infected mothers is likely to improve vaccine outcomes in this setting.

A Gravity-Fed Transcardial Perfusion Method for Histologic Analysis of the Mouse Central Nervous System.

The histologic analysis of brain and spinal cord specimens isolated from mice is common practice for the assessment of pathology in this model system. To maintain the morphology of these delicate tissues, it is routine to administer a chemical fixative such as paraformaldehyde via cannulation of the heart in anesthetized animals (transcardial perfusion). Transcardial perfusion of the mouse heart has traditionally relied on the use of peristaltic pumps or air pressure to deliver both the saline and fixative solutions necessary for this process. As an easily accessible alternative to these methods, this work demonstrates the use of a gravity-fed method of perfusate delivery that uses materials available in most hardware stores. To validate this new perfusion method, this work demonstrates all the subsequent steps necessary for the sensitive detection of phosphorylated α-synuclein in both the brain and spinal cord. Included in these steps are the dissection of the fixed brain and spinal cord tissues, rapid freezing/embedding and cryosectioning of the tissues, and immunofluorescent staining. As this method results in whole-body delivery of the fixative, it may also be used to prepare other non-neuronal tissues for histologic analysis.

A Gravity-Fed Transcardial Perfusion Method for Histologic Analysis of the Mouse Central Nervous System

The histologic analysis of brain and spinal cord specimens isolated from mice is common practice for the assessment of pathology in this model system. To maintain the morphology of these delicate tissues, it is routine to administer a chemical fixative such as paraformaldehyde via cannulation of the heart in anesthetized animals (transcardial perfusion). Transcardial perfusion of the mouse heart has traditionally relied on the use of peristaltic pumps or air pressure to deliver both the saline and fixative solutions necessary for this process. As an easily accessible alternative to these methods, this work demonstrates the use of a gravity-fed method of perfusate delivery that uses materials available in most hardware stores. To validate this new perfusion method, this work demonstrates all the subsequent steps necessary for the sensitive detection of phosphorylated α-synuclein in both the brain and spinal cord. Included in these steps are the dissection of the fixed brain and spinal cord tissues, rapid freezing/embedding and cryosectioning of the tissues, and immunofluorescent staining. As this method results in whole-body delivery of the fixative, it may also be used to prepare other non-neuronal tissues for histologic analysis.

Connected by the cord—comparison of drug positivity rates and concentrations in a large cohort of paired umbilical cord and meconium specimens

Abstract Substance abuse during pregnancy has significant short- and long-term health, social, and legal implications. Hence, prompt determination of a neonate’s drug exposure status can aid the healthcare team in making treatment choices. Umbilical cord tissue (UC) and meconium are two commonly used specimens to detect fetal drug exposure. However, the current evidence on the sensitivity of one specimen over the other is both limited and conflicting. By utilizing a large cohort (n=4036) of paired UC and meconium samples originating from 13 states, we retrospectively investigated the qualitative and quantitative drug positivity rates for 31 analytes from 5 drug classes (i.e. cannabis, opioids, stimulants, barbiturates, and benzodiazepines). Semi-quantitative drug detection in UC samples was conducted by LC-MS-based assays, whereas an immunoassay screen preceded quantitative LC-MS analysis for meconium specimens. Data were analyzed using R-programming, Microsoft Excel, and GraphPad Prism packages. The overall drug positivity rate for UC was 56.57% compared to 52.38% in meconium. Opioids were the top drug class detected in UC at 35.53% compared to 20.64% in meconium. The detection rates for individual opioid analytes were also higher in UC (0.97-15.49%) relative to meconium (0.0 to 9.09%). Notably, 6-acetylmorphine (heroin metabolite) was only detected in UC (0.97%). In contrast, 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC) was more frequently detected in meconium at 34.99% compared to 19.89% in UC. In the stimulant drug class, the overall amphetamine positivity rate was 7.73% in UC while 8.57% in the meconium specimens. Conversely, the cocaine positivity rate in the UC was 3.84% and 2.23% in meconium samples. In the barbiturate drug class, the positivity rate for butalbital was twice as high in UC (1.91%) relative to meconium (0.99%). Phenobarbital positivity rate was comparable in both matrices (~0.15%). The positivity rates for 6 common benzodiazepine drugs ranged from 0.40-0.94% in UC compared to 0.01-0.35% in meconium. Interestingly, a multidrug combination analysis revealed that THC−opioids was the most common two-drug combination detected in both matrices at a rate of 7.22% in UC compared to 5.39% in meconium. Subsequent examination of analyte concentrations between the two matrices revealed higher concentrations in meconium. THC was 48.13 times more concentrated in meconium relative to UC. Amphetamines and cocaine were 6.45-15.01 times more concentrated in meconium relative to UC. For the opioids, the overall concentrations were 21.61-1845.01 times higher in meconium specimens relative to UC. For barbiturates, butalbital had comparable concentrations in the two matrices whereas phenobarbital was 33.10 times more concentrated in the meconium. Lastly, benzodiazepines were overall 6.21-38.75 times more concentrated in meconium than UC. In conclusion, this study shows that despite most drugs being more concentrated in meconium, drug positivity rates were higher with UC for all analytes except THC and amphetamines, suggesting higher detection potential of the UC specimen.

Dexmedetomidine alleviates traumatic spinal cord injury in rats via inhibiting apoptosis induced by endoplasmic reticulum stress

ABSTRACT Objective To investigate the protective effect of dexmedetomidine (Dex) on traumatic spinal cord injury (TSCI) and to evaluate the involvement of inhibition of endoplasmic reticulum (ER) stress response in the potential mechanism. Method Sprague–Dawley rats were randomly divided into five groups. The hind limb locomotor function of rats was evaluated at 1, 3 and 7 days after the operation. At 7 days after the operation, spinal cord specimens were obtained for hematoxylin and eosin (H&E), Nissl and TUNEL staining, as well as immunofluorescence and Western blot analyses to detect the level of apoptosis and the levels of proteins related to ER stress. Results 7 days after the operation, Dex treatment promoted the recovery and also inhibited apoptosis of neurons in the spinal cord. Additionally, Dexinhibited the expression of proteins related to ER stress response after spinal cord injury. Conclusions Dex improves the neurological function of rats with TSCI and reduces apoptosis of spinal cord neurons. The potential mechanism is related to the inhibition of the ER stress response.

Ultrahigh-b diffusion-weighted imaging for quantitative evaluation of myelination in shiverer mouse spinal cord.

To perform a quantitative evaluation of myelination on WT and myelin-deficient (shiverer) mouse spinal cords using ultrahigh-b diffusion-weighted imaging (UHb-DWI). UHb-DWI of ex vivo on spinal cord specimens of two shiverer (C3HeB/FeJ-shiverer, homozygous genotype for MbPshi ) and six WT (Black Six, C3HeB/FeJ) mice were acquired using 3D multishot diffusion-weighted stimulated-echo EPI, a homemade RF coil, and a small-bore 7T MRI system. Imaging was performed in transaxial plane with 75 × 75 μm2 in-plane resolution, 1-mm-slice thickness, and radial DWI using bmax = 42,890 s/mm2 . Histological evaluation was performed on upper thoracic sections using optical and transmission electron microscopy. Numerical Monte Carlo simulations (MCSs) of water diffusion were performed to facilitate interpretation of UHb-DWI signal-b curves. The white matter ultrahigh-b radial DWI (UHb-rDWI) signal-b curves of WT mouse cords behaved biexponentially with high-b diffusion coefficient DH < 0.020 × 10-3 mm2 /s. However, as expected with less myelination, the signal-b of shiverer mouse cords behaved monoexponentially with significantly greater DH = 0.162 × 10-3 , 0.142 × 10-3 , and 0.164 × 10-3 mm2 /s at anterodorsal, posterodorsal, and lateral columns, respectively. The axial DWI signals of all mouse cords behaved monoexponentially with D = (0.718-1.124) × 10-3 mm2 /s. MCS suggests that these elevated DH are mainly induced by increased water exchange at the myelin sheath. Microscopic results were consistent with the UHb-rDWI findings. UHb-DWI provides quantitative differences in myelination of spinal cords from myelin-deficit shiverer and WT mice. UHb-DWI may become a powerful tool to evaluate myelination in demyelinating disease models that may translate to human diseases, including multiple sclerosis.

Meningeal B Cell Clusters Correlate with Submeningeal Pathology in a Natural Model of Multiple Sclerosis.

Multiple sclerosis (MS) is an idiopathic demyelinating disease in which meningeal inflammation correlates with accelerated disease progression. The study of meningeal inflammation in MS has been limited because of constrained access to MS brain/spinal cord specimens and the lack of experimental models recapitulating progressive MS. Unlike induced models, a spontaneously occurring model would offer a unique opportunity to understand MS immunopathogenesis and provide a compelling framework for translational research. We propose granulomatous meningoencephalomyelitis (GME) as a natural model to study neuropathological aspects of MS. GME is an idiopathic, progressive neuroinflammatory disease of young dogs with a female bias. In the GME cases examined in this study, the meninges displayed focal and disseminated leptomeningeal enhancement on magnetic resonance imaging, which correlated with heavy leptomeningeal lymphocytic infiltration. These leptomeningeal infiltrates resembled tertiary lymphoid organs containing large B cell clusters that included few proliferating Ki67+ cells, plasma cells, follicular dendritic/reticular cells, and germinal center B cell-like cells. These B cell collections were confined in a specialized network of collagen fibers associated with the expression of the lympho-organogenic chemokines CXCL13 and CCL21. Although neuroparenchymal perivascular infiltrates contained B cells, they lacked the immune signature of aggregates in the meningeal compartment. Finally, meningeal B cell accumulation correlated significantly with cortical demyelination reflecting neuropathological similarities to MS. Hence, during chronic neuroinflammation, the meningeal microenvironment sustains B cell accumulation that is accompanied by underlying neuroparenchymal injury, indicating GME as a novel, naturally occurring model to study compartmentalized neuroinflammation and the associated pathology thought to contribute to progressive MS.

Intra-dural intercommunications between dorsal roots of adjacent spinal nerves and their clinical significance.

The dorsal roots of adjacent spinal nerves are known to communicate with each other through rami communicantes. These intercommunications can cause deviations in the normal dermatomal organization which leads to errors during clinical decision-making. The objective of the study was to augment the existing knowledge of these communications which shall help minimize the diagnostic and therapeutic errors. The present study examined thirty cadaveric spinal cord specimens to document the data of intra-dural, intercommunications between dorsal roots of adjacent spinal nerves. All the regions of the spinal cord exhibited the presence of intercommunications with variable frequency. The intercommunications were categorized into a total of nine groups based on their patterns. The levels of spinal cord exhibiting higher and lower frequencies of intercommunications were identified. This information will be useful during the clinical evaluation of patients with spinal cord pathologies or radiculopathies. The outcomes of rhizotomy can also be improved with knowledge of intercommunications.