Ventral Root Research Articles

Extradural contralateral S1 nerve root transfer for spastic lower limb paralysis.

The current study aims to ascertain the anatomical feasibility of transferring the contralateral S1 ventral root (VR) to the ipsilateral L5 VR for treating unilateral spastic lower limb paralysis. Six formalin-fixed (three males and three females) cadavers were used. The VR of the contralateral S1 was transferred to the VR of the ipsilateral L5. The sural nerve was selected as a bridge between the donor and recipient nerve. The number of axons, the cross-sectional areas and the pertinent distances between the donor and recipient nerves were measured. The extradural S1 VR and L5 VR could be separated based on anatomical markers of the dorsal root ganglion. The gross distance between the S1 nerve root and L5 nerve root was 31.31 (± 3.23) mm in the six cadavers, while that on the diffusion tensor imaging was 47.51 (± 3.23) mm in 60 patients without spinal diseases, and both distances were seperately greater than that between the outlet of S1 from the spinal cord and the ganglion. The numbers of axons in the S1 VRs and L5 VRs were 13 414.20 (± 2 890.30) and 10 613.20 (± 2 135.58), respectively. The cross-sectional areas of the S1 VR and L5 VR were 1.68 (± 0.26) mm 2 and 1.08 (± 0.26) mm 2, respectively. In conclusion, transfer of the contralateral S1 VR to the ipsilateral L5 VR may be an anatomically feasible treatment option for unilateral spastic lower limb paralysis.

Research progress on nasopalatine canal type and its relationship with central incisor position

In recent years, the study of planting technology has received extensive attention and has achieved remarkable results at present. For example, implants are used to restore missing teeth and microimplants are used to adduct anterior teeth with large absolute anchorage to achieve satisfactory orthodontic treatment. However, in clinical practice, whether in the process of restorative treatment or orthodontic treatment, due to the existence of nasopalatine canal, an important bony tubular structure, it increases the risk of implant failure in anterior maxilla implant therapy; it also increases the risk of root resorption caused by excessive anterior adduction and root invasion of nasopalatine canal during orthodontic treatment[1] . Based on this, this paper systematically combs, summarizes and reviews the research status of the nasopalatine canal and its position with the central incisors in recent years in order to provide reference and enlightenment for subsequent researchers.

Human dental pulp stem cell monolayer and spheroid therapy after spinal motor root avulsion in adult rats

Spinal cord injuries result in severe neurological deficits and neuronal loss, with poor functional recovery. Mesenchymal stem cells have shown promising results; therefore the present objective of this work was to compare motor recovery after treatment with human dental pulp stem cells (hDPSC) cultivated in monolayer (2D) or as spheroids (3D), following avulsion and reimplantation of spinal motor roots in adult rats. Thus, 72 adult female Lewis rats were divided into 4 groups: avulsion (AV); avulsion followed by reimplantation (AR); avulsion associated with reimplant and 2D cell therapy (AR + 2D), and avulsion associated with reimplant and 3D cell therapy (AR + 3D). The application of the cells in 2D and 3D was performed by microsurgery, with subsequent functional assessment using a walking track test (Catwalk system), immunohistochemistry, neuronal survival, and qRT-PCR in 1-, 4-, and 12-weeks post-injury. The animals in the AR + 2D and AR + 3D groups showed the highest neuronal survival rates, and immunofluorescence revealed downregulation of GFAP, and Iba-1, with preservation of synaptophysin, indicating a reduction in glial reactivity, combined with the maintenance of pre-synaptic inputs. There was an increase in anti-inflammatory (IL-4, TGFβ) and a reduction of pro-inflammatory factors (IL-6, TNFα) in animals treated with reimplantation and hDPSC. As for the functional recovery, in all analyzed parameters, the AR + 2D group performed better and was superior to the avulsion alone. Overall, our results indicate that the 2D and 3D cell therapy approaches provide successful immunomodulation and motor recovery, consistent with advanced therapies after spinal cord injury.

Time-course gait pattern analysis in a rat model of foot drop induced by ventral root avulsion injury.

Foot drop is a common clinical gait impairment characterized by the inability to raise the foot or toes during walking due to the weakness of the dorsiflexors of the foot. Lumbar spine disorders are common neurogenic causes of foot drop. The accurate prognosis and treatment protocols of foot drop are not well delineated in the scientific literature due to the heterogeneity of the underlying lumbar spine disorders, different severities, and distinct definitions of the disease. For translational purposes, the use of animal disease models could be the best way to investigate the pathogenesis of foot drop and help develop effective therapeutic strategies for foot drops. However, no relevant and reproducible foot drop animal models with a suitable gait analysis method were developed for the observation of foot drop symptoms. Therefore, the present study aimed to develop a ventral root avulsion (VRA)-induced foot drop rat model and record detailed time-course changes of gait pattern following L5, L6, or L5 + L6 VRA surgery. Our results suggested that L5 + L6 VRA rats exhibited changes in gait patterns, as compared to sham lesion rats, including a significant reduction of walking speed, step length, toe spread, and swing phase time, as well as an increased duration of the stance phase time. The ankle kinematic data exhibited that the ankle joint angle increased during the mid-swing stage, indicating a significant foot drop pattern during locomotion. Time-course observations displayed that these gait impairments occurred as early as the first-day post-lesion and gradually recovered 7-14 days post-injury. We conclude that the proposed foot drop rat model with a video-based gait analysis approach can precisely detect the foot drop pattern induced by VRA in rats, which can provide insight into the compensatory changes and recovery in gait patterns and might be useful for serving as a translational platform bridging human and animal studies for developing novel therapeutic strategies for foot drop.

Quercetin enhances survival and axonal regeneration of motoneurons after spinal root avulsion and reimplantation: experiments in a rat model of brachial plexus avulsion

BackgroundBrachial plexus avulsion (BPA) physically involves the detachment of spinal nerve roots themselves and the associated spinal cord segment, leading to permanent paralysis of motor function of the upper limb. Root avulsion induces severe pathological changes, including inflammatory reaction, oxidative damage, and finally massive motoneuron apoptosis. Quercetin (QCN), a polyphenolic flavonoid found in abundance in fruit and vegetables, has been reported to possess anti-oxidative, anti-inflammatory, and neuroprotective effects in many experimental models of both central nervous system (CNS) and peripheral nervous system (PNS) disorders. The purpose of this study was to investigate whether QCN could improve motor function recovery after C5–7 ventral root avulsion and C6 reimplantation in a rat model of BPA.MethodsThe right fifth cervical (C5) to C7 ventral roots were avulsed followed by re-implantation of only C6 to establish the spinal root avulsion plus re-implantation model in rats. After surgery, rats were treated with QCN (25, 50, and 100 mg/kg) by gavage for 2 or 8 consecutive weeks. The effects of QCN were assessed using behavior test (Terzis grooming test, TGT) and histological evaluation. The molecular mechanisms were determined by immunohistochemistry analysis and western blotting.ResultsOur results demonstrated that QCN significantly expedited motor function recovery in the forelimb as shown by the increased Terzis grooming test score, and accelerated motor axon regeneration as evidenced by the ascending number of Fluoro-Ruby-labeled and P75-positive regenerative motoneurons. The raised ChAT-immunopositive and cresyl violet-stained neurons indicated the enhanced survival of motoneurons by QCN administration. Furthermore, QCN treatment markedly alleviated muscle atrophy, restored functional motor endplates in biceps and inhibited the microglial and astroglia activation via modulating Nrf2/HO-1 and neurotrophin/Akt/MAPK signaling pathway.ConclusionsTaken together, these findings have for the first time unequivocally indicated that QCN has promising potential for further development into a novel therapeutic in conjunction with reimplantation surgery for the treatment of BPA.

Combined Medial Meniscus Allograft Transplantation and Open-Wedge High Tibial Osteotomy Using a Patient-Specific Instrumentation Guide

Despite technical advances in meniscus allograft transplantation, there remains a need to improve postoperative outcomes.1,2 The bone plugs technique using osseous fixation of the anterior and posterior roots has demonstrated increased stability and long-term survival. Recently, the importance of limb alignment has been demonstrated for this procedure. In case of malalignment, osteotomy is essential to improve the long-term viability of both meniscus allograft and cartilage. The recent introduction of patient-specific instrumentation has raised the possibility of making instrumentation specific to each patient achieving an optimal correction in a safe and reliable manner. This Technical Note describes the use of a combined medial meniscus allograft transplantation and open wedge high tibial osteotomy using a patient-specific instrumentation guide.

Contrast Spread After Erector Spinae Plane Block at the Fourth Lumbar Vertebrae: A Cadaveric Study.

In recent years, the erector spinae plane block (ESPB) has seen widespread use to treat acute and chronic pain in the regions of the thoracic spine. While limited data suggest its increasing utilization for pain management distal to the thoracic, abdomen and trunk, the anesthetic spread and analgesic mechanism of ESPB at the level of the lumbar spine has not been fully described or understood. This is an observational anatomic cadaveric study to assess the distribution of solution following an ESPB block performed at the fourth lumbar vertebrae (L4) using ultrasound guidance to evaluate the spread of a 20ml solution consisting of local anesthetic and methylene blue. The study was performed in an anatomy lab in a large academic medical center. Following injection of local anesthetic with contrast dye, cadaveric dissection was performed to better understand the extent of contrast dye and to determine the degree of staining to further predict analgesic potential. We reviewed the findings of other ESPB cadaveric studies currently available for comparison. Following cadaveric dissection in an anatomy lab, the contrast dye was observed in the ESP space, and staining was found most cranially at L2 and extending caudally underneath the sacrum. Evaluating the depth of its spread, we found it to be confined to the posterior compartment of the spine sparing the nerve roots bilaterally, which is consistent with the only other cadaveric study of ESPB performed at L4. Our results demonstrate the clinical utility of lumbar ESPB where posterior confinement of local anesthesia is preferred. However, further investigation is needed to determine the efficacy of ESPB in lower extremity analgesia which is predicated on ventral nerve root involvement.

Morphometric analysis of the spinal cord of the Sus scrofa (large white and landrace crossbreed).

The incidence of spinal cord (SC) injury in developed and undeveloped countries is alarming. The pig (Sus scrofa) has been recommended as a suitable research model for translational studies because of its morphophysiological similarities of organ systems with humans. There is a dearth of information on the SC anatomy of the large white and landrace crossbreed (LW-LC) pigs. We therefore aim to describe the gross morphology and morphometry of its SC. Twelve juvenile LW-LC pigs (six males and six females) were used. The skin and epaxial muscles were dissected to expose the vertebral column. The SC was carefully harvested by laminectomy, and 13 gross SC morphometric parameters were evaluated. Thirty-three spinal nerves were seen emanating from either side of the SC by means of dorsal and ventral spinal roots. The overall average of SC length and weight was 36.23 ± 1.01 cm and 16.60 ± 0.58 g, respectively. However, the mean SC length and weight were higher in females compared with males, with SC weight being statistically significant. A positive relationship between SC length and weight was significant for males (p=0.0435) but not for females (p=0.42). Likewise, the strength of the relationship between SC length and weight was significant in males (r=0.82) but not significant in females (r=0.41). Baseline data for the morphometric features of the spinal cord in the LW-LC pigs were generated, which will contribute to the knowledge of this species anatomy and useful information on regional anaesthesia that should further strengthen the drive in adopting the pig as a suitable research model for biomedical research.

Effect of cisplatin on respiratory activity in neonatal rats.

One side effect of cisplatin, a cytotoxic platinum anticancer drug, is peripheral neuropathy; however, its central nervous system effects remain unclear. We monitored respiratory nerve activity from the C4 ventral root in brainstem and spinal cord preparations from neonatal rats (P0-3) to investigate its central effects. Bath application of 10-100μM cisplatin for 15-20min dose-dependently decreased the respiratory rate and increased the amplitude of C4 inspiratory activity. These effects were not reversed after washout. In separate perfusion experiments, cisplatin application to the medulla decreased the respiratory rate, and application to the spinal cord increased the C4 burst amplitude without changing the burst rate. Application of other platinum drugs, carboplatin or oxaliplatin, induced no change of respiratory activity. A membrane potential analysis of respiratory-related neurons in the rostral medulla showed that firing frequencies of action potentials in the burst phase tended to decrease during cisplatin application. In contrast, in inspiratory spinal motor neurons, cisplatin application increased the peak firing frequency of action potentials during the inspiratory burst phase. The increased burst amplitude and decreased respiratory frequency were partially antagonized by riluzole and picrotoxin, respectively. Taken together, cisplatin inhibited respiratory rhythm via medullary inhibitory system activation and enhanced inspiratory motor nerve activity by changing the firing property of motor neurons.

Motor and somatosensory degenerative myelopathy responsive to pantothenic acid in piglets.

This report describes 2 events of degenerative myelopathy in 4- to 27-day-old piglets, with mortality rates reaching 40%. Sows were fed rations containing low levels of pantothenic acid. Piglets presented with severe depression, weakness, ataxia, and paresis, which were more pronounced in the pelvic limbs. No significant gross lesions were observed. Histologically, there were degeneration and necrosis of neurons in the spinal cord, primarily in the thoracic nucleus in the thoracic and lumbar segments, and motor neurons in nucleus IX of the ventral horn in the cervical and lumbar intumescence. Minimal-to-moderate axonal and myelin degeneration was observed in the dorsal funiculus of the spinal cord and in the dorsal and ventral nerve roots. Immunohistochemistry demonstrated depletion of acetylcholine neurotransmitters in motor neurons and accumulation of neurofilaments in the perikaryon of neurons in the thoracic nucleus and motor neurons. Ultrastructurally, the thoracic nucleus neurons and motor neurons showed dissolution of Nissl granulation. The topographical distribution of the lesions indicates damage to the second-order neurons of the spinocerebellar tract, first-order axon cuneocerebellar tract, and dorsal column-medial lemniscus pathway as the cause of the conscious and unconscious proprioceptive deficit, and damage to the alpha motor neuron as the cause of the motor deficit. Clinical signs reversed and no new cases occurred after pantothenic acid levels were corrected in the ration, and piglets received parenteral administration of pantothenic acid. This study highlights the important and practical use of detailed neuropathological analysis to refine differential diagnosis.

Morphological Cross-Sectional Study of Anatomical Landmarks for Foramen Transversarium in Dry Human Cervical Vertebrae and its Surgical Importance

Background: Surgeries such as discectomy, intervertebral fusion, anterior microforaminotomy, and anterior screw fixation can damage neurovascular content of foramen transversarium of cervical vertebrae. The aim of this study was to measure outer limit and strength of foramen transversarium with help of uncinate process, anterior tubercle, and anterior root thickness. Methodology: A total of 54 dried human cervical vertebrae collected from anatomy department. Only third to seventh cervical vertebrae were included. Digital vernier caliper was used to measure transverse length (TL) of body, bilateral distance of uncinate process, and anterior tubercle from mid of cervical vertebral body and thickness of mid of anterior root. Results: Mean TL of body of cervical vertebrae was 23.87 mm, mean distance of uncinate process from vertebral body was 9.14 mm on right and 8.49 mm on left (P < 0.0001), mean distance of anterior tubercle from vertebral body was 20.81 mm on right and 20.36 mm on left (P < 0.014), mean thickness of anterior root was 1.48 mm on right and 1.36 mm on left (P < 0.1003) whereas mean distance between uncinate process was 18.4 mm. Conclusion: Mean TL of cervical vertebrae was 23.8 mm, distance of uncinate process was 8.81 mm from the center, distance of anterior tubercle to uncinate process was 20.72 mm and thickness of anterior root was 1.43 mm. Uncinate process and anterior tubercle distance from mid of cervical vertebrae body can help surgeons to identify zone and avoid injury to contents.

Evaluation of histogram equalization and contrast limited adaptive histogram equalization effect on image quality and fractal dimensions of digital periapical radiographs.

This study aims to evaluate the effects of histogram equalization (HE) and contrast limited adaptive histogram equalization (CLAHE) on periapical images and fractal dimensions in the periapical region. In this cross-sectional study, digital periapical images were selected from the archive of Dentistry School of Isfahan University of Medical Sciences. The radiographs were taken from mandibular and maxillary anterior single root teeth with healthy root and periodontium. After applying HE and CLAHE algorithms to images, two radiologists evaluated the quality of apex detection from using a 5-point Likert scale (from 5 for very good image quality to 1 for very bad image quality). Afterward, all the images were imported to the ImageJ application, and the region of interest (ROI) was specified as the region between the two central incisors. The fractal box-counting method was used to determine fractal dimensions (FD) values. Nonparametric Wilcoxon-Friedman test, Intraclass Correlation Coefficient test, T-test, and Pair T-test were performed as statistical analysis (α = 0.05). Fifty-three radiographs were analyzed and the image quality assessments were significantly different between raw images and images after performing HE, CLAHE (p value < 0.001), and using CLAHE algorithm significantly increases image quality assessments more than HE (p value = 0.009). There was a significant difference in FD values for images after applying CLAHE and HE compared to raw images (p value < 0.001), and HE decreased the FD value significantly more than CLAHE (p value = 0.019). Employing CLAHE and HE algorithm via OpenCV python library improves the periapical image quality, which is more significant using the CLAHE algorithm. Moreover, applying CLAHE and HE reduces trabecular bone structure detection and FD values in periapical images, especially in HE.

All-Soft Tissue Meniscus Allograft Transplantation: Indications, Techniques, and Results

Background: Meniscus allograft transplantation (MAT) may be indicated for young patients with joint line pain following subtotal or total meniscectomy. Several different approaches for performing MAT have been described in the literature and are influenced by appropriate patient selection, graft-sizing, and soft-tissue fixation techniques. Clinical studies demonstrate favorable results regarding pain relief and knee function in young patients undergoing MAT, making it a viable option for the treatment of postmeniscectomy syndrome. Indications: Meniscus allograft transplantation is indicated for symptomatic patients following subtotal or total meniscectomy. Selection criteria include patient age below 40 to 45 years, body mass index below 35, chondral changes of grade 2 or less, anatomic or correctable joint alignment, and normal or correctable knee stability. Technique Description: A standard arthroscopy is performed to confirm the indication for MAT, followed by debridement of the meniscus remnant up to the meniscus-capsular junction. The meniscus horns are prepared using a single No. 5 suture, while 4 to 5 No. 2 sutures are passed through the posterior body. The anterior and posterior root tunnels are drilled, and the meniscus is inserted through a posterior vertical arthrotomy using suture passers transmitted via the bone tunnels. The allograft is manipulated into proper position with a probe and the application of axial traction on the posterior root suture. At this point, sutures attached to the posterior horn are passed to the posterior capsule and 6 to 8 inside-out sutures are used to stabilize and fixate the midbody and anterior portion of the allograft. Results: Several clinical studies report good outcomes following MAT with a mean survival rate of approximately 70% at 10-year follow-up and 60% at 15 years. Additionally, some evidence is currently available regarding the long-term chondroprotective effect of MAT. Description/Conclusion: All-soft tissue meniscus allograft transplantation is a feasible approach for substitution of the damaged native meniscus and maintenance of tibiofemoral contact mechanics. Consequently, MAT is an important procedure in the toolkit of knee surgeons providing treatment for young, symptomatic postmeniscectomy patients.

Brain Insulin Receptor Antagonism Augments The Blood Pressure Response To Activation Of The Exercise Pressor Reflex

Type 2 diabetes mellitus (T2DM) results in abnormal control of blood pressure (BP). However, the underlying mechanisms remain to be elucidated. The transport of insulin into the central nervous system is decreased in T2DM. The resultant central hypoinsulinemia reduces neuronal excitability. The nucleus tractus solitarius (NTS) is a key central integration site for incoming signals from peripheral sensory neurons including input from working skeletal muscle and arterial baroreceptors. Working skeletal muscle activates primary sensory fibers and evokes the exercise pressor reflex (EPR) to reflexively increase BP, a response modulated by the baroreflex. Central hypoinsulinemia in T2DM may influence how neurons in the NTS process this sensory information during exercise affecting BP responsiveness. PURPOSE: To determine whether acute antagonism of insulin receptors in the NTS alters EPR function in baro-intact and barodenervated rats. METHODS: L4 and L5 ventral roots were electrically stimulated in healthy decerebrated male Sprague-Dawley rats to evoke hindlimb muscle contraction and EPR activation in intact and sino-aortic barodenervated rats. Mean arterial pressure (MAP) responses to activation of the EPR were assessed before and 30 min following NTS microinjections of the insulin receptor antagonist, GSK1838705 (100uM), or vehicle, dimethyl sulfoxide (DMSO). RESULTS: In baro-intact rats, contraction-induced changes in MAP were significantly greater following GSK1838705 (Pre, 16 ± 10 mmHg vs. Post, 23 + 13 mmHg, n = 11, p < 0.01) but not DMSO (Pre, 15 ± 8 mmHg vs. Post, 15 + 8 mmHg, n = 9). In barodenervated rats, neither GSK1838705 (Pre, 27 ± 16 mmHg vs. Post, 28 ± 21 mmHg, n = 8) nor DMSO (Pre, 34 ± 17 mmHg vs. Post, 30 ± 27 mmHg, n = 9) affected the MAP response to contraction. CONCLUSIONS: The findings demonstrate that central insulin receptor antagonism augments the BP response to EPR activation, which is abolished by barodenervation. The findings also suggest that insulin in the NTS maintains the capacity to buffer EPR-mediated increases in BP via baroreflex-mediated mechanisms. Alterations in this buffering capacity due to the central hypoinsulinemia in T2DM could account, in part, for the exaggerated pressor response to exercise in this disease. Supported by NIH-NHLBI, Lawson & Rogers Lacy Research Fund.

Assessment of Anatomic Restoration and Clinical Outcomes Between Medial and Lateral Meniscal Allograft Transplantation.

Background:Proper anatomic restoration is an important consideration for meniscal allograft transplantation (MAT), even with the different anatomica characteristics between the medial meniscus and lateral meniscus.Purpose/Hypothesis:The purpose of this study was to assess the accuracy of anatomic restoration in medial and lateral MAT (MMAT and LMAT) procedures and to compare their outcomes. We hypothesized that (1) the anatomic differences between the medial and lateral menisci will mean a less accurate anatomic restoration for MMAT and (2) clinical outcomes after MMAT will be inferior compared with LMAT.Study Design:Cohort study; Level of evidence, 3.Methods:We retrospectively evaluated 20 patients who underwent MMAT using the bone plug technique and 21 patients who underwent LMAT using the keyhole technique at a single institution from July 2014 to June 2019. Demographic data, previous surgeries, and concomitant procedures were recorded, as were lower limb alignment and osteoarthritis grade on radiographs. Using preoperative and follow-up magnetic resonance imaging, the meniscal position, rotation, extrusion, and intrameniscal signal intensity were evaluated. Clinical outcomes were evaluated using the International Knee Documentation Committee and Lysholm scores.Results:The mean follow-up was 41.15 ± 18.86 and 45.43 ± 21.32 months for the MMAT and LMAT patients, respectively. Concomitant procedures were performed in 90% of MMATs and 15% of LMATs. There was no significant difference between the native and postoperative root positions after LMAT; however, for MMAT, the position of the anterior root was located significantly posteriorly (P = .002) and medially (P = .007) compared with preoperatively. In addition, the allograft medial meniscus was restored in a more internally rotated position (P = .029). MMATs also exhibited significantly increased meniscal extrusion compared with LMATs (posterior horn, P < .001; midbody, P = .027; anterior horn, P = .006). However, there was no significant difference between the 2 groups at final follow-up in intrameniscal signal intensity or clinical scores.Conclusion:LMAT showed higher accuracy than MMAT in restoring meniscal position and rotation, and there was less meniscal extrusion. However, clinical scores improved after both LMAT and MMAT compared with preoperative values, and midterm clinical outcomes were similar. The small anatomical errors seen in the MMAT technique were not clinically relevant at midterm follow-up.

Morphological changes in nerve rootlets in patients with cervical radiculopathy assessed using computed tomography myelogram.

Background: There are only a few reports that utilize computed tomography myelogram (CTM) to define cervical nerve rootlet compromise in patients with radiculopathy. Here, we assessed the characteristic morphological changes in nerve rootlets in 32 cases with cervical radiculopathy by analyzing CTMs warranting anterior foraminotomy.Methods: CTMs were analyzed to elucidate morphological changes in nerve rootlets in 31 patients/32 cases with cervical radiculopathy. Notably, three of the four neurosurgeons evaluating these CTM had to agree on the presence of “significant” changes consisting of contrast-enhanced defects near the entrance of the intervertebral foramen on axial sections.Results: Our findings included; posterior deviation of the ventral rootlet on the sagittal section (63%), ventral rootlet meandering or horizontalization (52%), and dorsal rootlet meandering (39%) on the coronal section. Furthermore, 16% of cervical nerve rootlets may exhibit an abnormal course proximal to the compression site (i.e., the definition of the “rootlet stagnation sign”).Conclusion: CTM better defines the anatomy, pathology, and radiology impacting the anterior or posterior cervical roots in patients presenting with cervical radiculopathy.

Ultrasensitive Acetylcholinesterase detection based on a surface-enhanced Raman scattering lever strategy for identifying nerve fibers

Accurate discriminating nerve fibers is a prerequisite for right suturing nerves in nerve transfer operation. Various methods have been developed for identification of motor and sensory fibers, but no simple method meets the requirements in clinic. In this study, a surface-enhanced Raman scattering (SERS) lever strategy is designed and developed to detect Acetylcholinesterase (AchE) ultrasensitively, in which using produced thiocholine with weak intrinsic Raman activity (four ounces) to adjust absorbance of Rhodamine B with strong intrinsic Raman activity (thousand catties) on SERS-active substrates is to increase the sensitivity. Employing a miniaturized SERS substrate, SERS-active microneedles, is to decrease the volume of enzymolysis systems. Adopting an internal reference is to increase the repeatability of collected signal. The ultrasensitive AchE detection method discriminate samples with four times of difference in enzyme activity between 1–1 × 10−4 U/mL in about 10 min of enzymolysis time. AchE amounts in 2-mm-long segments of ventral and dorsal roots were about 0.00025–0.001 U and 0.01–0.02 U, respectively. The developed method would be a reliable method met the requirements of identifying motor and sensory fibers in clinic.

Are superficial neuromasts proprioceptors underlying fast copulatory behavior?

In male Poeciliid fishes, the modified anal fin (i.e., gonopodium) and its axial and appendicular support are repositioned within the axial skeleton, creating a novel sexually dimorphic ano-urogenital region. During copulation, the relative location of the gonopodium is crucial for successful insemination. Therefore, the repositioning of these structures and organ relied on the reorganization of the efferent circuitry that controls spinal motor neurons innervating appendicular muscles critical for the movement of the gonopodium, including the fast and synchronous torque-trust motion during insemination attempts. Copulation occurs when a male positions himself largely outside a female’s field of view, circumducts his gonopodium, and performs a rapid, complex maneuver to properly contact the female urogenital sinus with the distal tip of the gonopodium and transfers sperm. Although understanding of the efferent circuitry has significantly increased in the last 24 years, nothing is known about the cutaneous receptors involved in gonopodium movement, or how the afferent signals are processed to determine the location of this organ during copulation. Using Western mosquitofish, Gambusia affinis, as our model, we attempt to fill this gap in knowledge. Preliminary data showed cutaneous nerves and sensory neurons innervating superficial neuromasts surrounding the base of adult male gonopodium; those cutaneous nerves projected ventrally from the spinal cord through the 14th dorsal root ganglion and its corresponding ventral root towards the base and fin rays of the gonopodium. We asked what role the cutaneous superficial neuromasts play in controlling the positioning and timing of the gonopodium’s fast and synchronous movements for effective sperm transfer. First, we found a greater number of superficial neuromasts surrounding the base of the male’s gonopodium compared to the base of the female’s anal fin. Second, we systemically removed superficial neuromasts surrounding the gonopodium base and observed significant impairment of the positioning and timing of gonopodial movements. Our findings provide a first step to supporting the following hypothesis: during radical reorganization of the Poeciliid body plan, superficial neuromasts have been partially co-opted as proprioceptors that allow the gonopodium to control precise positioning and timing during copulatory attempts.

Anatomical and Imaging Study on the Optimum Entry Point and Trajectory for Anterior Transpedicular Root Screw Placement into the Lower Cervical Spine.

Objective To study the optimum entry point and trajectory for anterior transpedicular root screw (ATPRS) placement into the lower cervical spine (LCS), so as to provide a basis for clinical application. Methods A retrospective analysis of cervical CT images of patients who underwent cervical CT examination in the Spinal Surgery of Ningbo No. 6 Hospital from January 2020 to August 2021 was conducted. The data were obtained and modeled. On the coronal plane, the vertebral body (VB) between the anterior midline of cervical vertebral segments C3-7 and the left P line (by drawing the line parallel to the anterior midline of the VB at the intersection of the anterior edge of the Luschka's joint and the upper endplate) was equally divided into 9 zones (a-i). The ideal entry point and path of cervical ATPRS were designed and recorded. Additionally, 7 cadaveric specimens were selected, and the screw placement parameters were regenerated according to the above methods for screw placement. Results Zone i of each segment, with the longest screw length, was the best area for screw placement. In all patients, the horizontal angles of vertebrae C3-7 in zones a, d, and g, zones b, e, and h, and zones c, f, and i showed a gradually decreasing trend. The sagittal angle range of C3-7 in all patients showed a gradually increasing trend in zones a-c, d-f, and g-i. The distance from the anterior midline of C3-7 to the P line increased in all patients, and the distance was longer in males than in females, with statistical significance. Pedicle screws were successfully inserted in all the 7 cadaveric specimens. Conclusions ATPRS placement can be used for LCS internal fixation, and the precise screw placement parameters can be simulated by the software, which provides theoretical basis for its future clinical application.

A Young Man With Acute-Onset Bilateral Arm Weakness After Traumatic Sciatic Neuropathy: A Clinical Vignette.

A Young Man With Acute-Onset Bilateral Arm Weakness After Traumatic Sciatic Neuropathy: A Clinical Vignette.