Motor nerve transplantation

1997 ◽  
Vol 87 (4) ◽  
pp. 615-624 ◽  
Author(s):  
William P. Gray ◽  
Catherine Keohane ◽  
William O. Kirwan
Keyword(s):  
Motor Nerve ◽  
Nerve Fibers ◽  
Nerve Graft ◽  
Motor Endplate ◽  
Denervated Muscle ◽  
Response Curves ◽  
Motor Endplates ◽  
Content Type ◽  
Nerve Transplantation ◽  
The Right

✓ The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 µsec preoperatively, and 26 µsec at 2 months, 29.5 µsec at 4 months, and 14 µsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle.

scholarly journals Motor nerve transplantation

1999 ◽  
Vol 7 (3) ◽  
pp. E7
Author(s):  
William P. Gray ◽  
Catherine Keohane ◽  
William O. Kirwan
Keyword(s):  
Motor Nerve ◽  
Nerve Fibers ◽  
Nerve Graft ◽  
Motor Endplate ◽  
Denervated Muscle ◽  
Response Curves ◽  
Motor Endplates ◽  
Nerve Transplantation ◽  
Isometric Twitch ◽  
The Right

The motor nerve transplantation (MNT) technique is used to transfer an intact nerve into a denervated muscle by harvesting a neurovascular pedicle of muscle containing motor endplates from the motor endplate zone of a donor muscle and implanting it into a denervated muscle. Thirty-six adult New Zealand White rabbits underwent reinnervation of the left long peroneal (LP) muscle (fast twitch) with a motor nerve graft from the soleus muscle (slow twitch). The right LP muscle served as a control. Reinnervation was assessed using microstimulatory single-fiber electromyography (SFEMG), alterations in muscle fiber typing and grouping, and isometric response curves. Neurofilament antibody was used for axon staining. The neurofilament studies provided direct evidence of nerve growth from the motor nerve graft into the adjacent denervated muscle. Median motor endplate jitter was 13 μsec preoperatively, and 26 μsec at 2 months, 29.5 μsec at 4 months, and 14 μsec at 6 months postoperatively (p < 0.001). Isometric tetanic tension studies showed a progressive functional recovery in the reinnervated muscle over 6 months. There was no histological evidence of aberrant reinnervation from any source outside the nerve pedicle. Isometric twitch responses and adenosine triphosphatase studies confirmed the conversion of the reinnervated LP muscle to a slow-type muscle. Acetylcholinesterase studies confirmed the presence of functioning motor endplates beneath the insertion of the motor nerve graft. It is concluded that the MNT technique achieves motor reinnervation by growth of new nerve fibers across the pedicle graft into the recipient muscle.

Loss of nitric oxide synthase immunoreactivity in cerebral vasospasm

1996 ◽  
Vol 84 (4) ◽  
pp. 648-654 ◽  
Author(s):  
Ryszard M. Pluta ◽  
B. Gregory Thompson ◽  
Ted M. Dawson ◽  
Solomon H. Snyder ◽  
Robert J. Boock ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Cerebral Vasospasm ◽  
Cerebral Artery ◽  
Cerebral Arteries ◽  
Nerve Fibers ◽  
Content Type ◽  
The Right ◽  
Oxide Synthase ◽  
Fine Print

✓ To determine the distribution of nitric oxide synthase (NOS) in the primate cerebral artery nervi vasorum and to examine the potential role of NOS in cerebral vasospasm after subarachnoid hemorrhage (SAH) in primates, the distribution of NOS immunoreactivity (NOS-IR) in the major cerebral arteries was examined immunohistochemically in cynomolgus monkeys by the use of whole, mounted preparations of the circle of Willis. In four normal monkeys, NOS-IR was localized to the endothelial and adventitial layers of the large cerebral arteries. On the abluminal side, NOS-IR staining was densely concentrated in perivascular nerve fibers (nervi vasorum) of the anterior circulation. Staining was less prominent in the posterior circulation. In six monkeys with vasospasm on Day 7 after placement of preclotted arterial blood to form an SAH around the right middle cerebral artery (MCA) (42% ± 8.3% decrease of MCA area, mean ± standard deviation), NOS-IR was virtually absent in nerve fibers around the spastic right MCA but was normal on the contralateral side. In five monkeys in which vasospasm resolved by Day 14 after SAH (36% ± 14% decrease of right MCA area on Day 7, and 5% ± 14% decrease on Day 14), NOS-IR was also absent in the right MCA adventitial nerve fibers and remained normal in the left MCA. Adventitial NOS-IR was also normal in cerebral vessels of a sham-operated, nonspastic monkey. These findings provide further evidence that nitric oxide (NO) functions as a neuronal transmitter to mediate vasodilation in primates and indicate a role for adventitial NO in the pathogenesis of cerebral vasospasm after SAH in humans.

scholarly journals The Physiological Significance of A-Waves in Early Diabetic Neuropathy: Assessment of Motor Nerve Fibers by Neurophysiological Techniques

2021 ◽  
Vol 15 ◽  
Author(s):  
Qiong Cai ◽  
Guliqiemu Aimair ◽  
Wen-Xiao Xu ◽  
Pei-Yao Xiao ◽  
Lie-Hua Liu ◽  
...  
Keyword(s):  
Conduction Velocity ◽  
Type Ii Diabetes ◽  
Motor Nerve ◽  
Clinical Information ◽  
Nerve Fibers ◽  
Diabetic Patients ◽  
Healthy Controls ◽  
Type Ii ◽  
Significant Difference ◽  
The Right

Objective: This study aimed to investigate how early A-waves could occur in type II diabetes, and what it implied functionally.Methods: We performed conduction velocity distribution (CVD) test in peroneal nerves of 37 type II diabetic patients with normal nerve conduction study (NCS) and 22 age-matched controls. The electrophysiological data and clinical information were analyzed.Results: A-waves were observed in 45.9% of diabetic patients and only in 1 person in healthy controls, all detected in the tibial nerves. The diabetic patients with A-waves showed faster conduction velocity in all quartiles in the motor peroneal nerves compared to the patients without A-waves, and their CVD histograms were shifted to the right side, consisting of a significantly larger percentage of fast conducting fibers. There was no significant difference in the CVD values of the upper extremity nerves among the patients with and without A-waves and the healthy controls.Conclusion: A-waves could occur in type II diabetes as early as when NCS showed normal, and represented as a sign of neuropathy as well as a sign of rescued motor nerve function.

Ridogrel Inhibits Systemic and Renal Formation of Thromboxane A2 and Antagonizes Platelet Thromboxane A2/Prostaglandin Endoperoxide Receptors upon Chronic Administration to Man

1992 ◽  
Vol 68 (02) ◽  
pp. 214-220 ◽  
Author(s):  
C Weber ◽  
J R Beetens ◽  
F Tegtmeier ◽  
P Van Rooy ◽  
E Vercammen ◽  
...  
Keyword(s):  
Uric Acid ◽  
Potent Inhibitor ◽  
Ex Vivo ◽  
Thromboxane A2 ◽  
Chronic Administration ◽  
Response Curves ◽  
Clinically Significant ◽  
Synthase Inhibitor ◽  
The Right ◽  
Steady State Plasma Level

SummaryThe effects of ridogrel, a dual thromboxane A2 (TXA2) synthase inhibitor and TXA2/prostaglandin (PG) endoperoxide receptor antagonist, on systemic and renal production of prostaglandins and on platelet TXA2/PG endoperoxide receptors was evaluated upon chronic administration (300 mg b. i. d. orally, for 8 and 29 days) to man. Such a medication with ridogrel inhibits the systemic as well as the renal production of TXA2 as measured by the urinary excretion of 2,3-dinor-TXB2 and TXB2 respectively without inducing significant changes in systemic or renal PGI2 production. Simultaneously with the latter effects, the production of TXB2 by spontaneously coagulated whole blood ex vivo is inhibited (>99%) while that of PGE2 and PGF2α is largely increased. Administration of ridogrel causes a three- to five-fold shift to the right of concentration-response curves for U46619 in eliciting platelet aggregation; no tachyphylaxis is observed after 29 days of treatment in this respect. Apart from a reduction of serum uric acid levels with a concomitant increase in urinary uric acid excretion during the first days of treatment, no clinically significant changes in hematological, biochemical, hemodynamic and coagulation parameters occur during the 8 days or 29 days study. The study demonstrates that ridogrel is a potent inhibitor of the systemic as well as renal TXA2 synthase and an antagonist of platelet TXA2/PG endoperoxide receptor in man, covering full activity during 24 h at steady-state plasma level conditions without tachyphylaxis during 29 days of medication. The compound is well tolerated, at least during 1 month of administration.

Human motor endplate remodeling after traumatic nerve injury

2020 ◽  
pp. 1-8
Author(s):  
Ranjan Gupta ◽  
Justin P. Chan ◽  
Jennifer Uong ◽  
Winnie A. Palispis ◽  
David J. Wright ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Surgical Intervention ◽  
Linear Regression Analysis ◽  
Motor Endplate ◽  
Nerve Injuries ◽  
Denervated Muscle ◽  
Sequence Of Events ◽  
Human Motor ◽  
Denervated Muscles

OBJECTIVECurrent management of traumatic peripheral nerve injuries is variable with operative decisions based on assumptions that irreversible degeneration of the human motor endplate (MEP) follows prolonged denervation and precludes reinnervation. However, the mechanism and time course of MEP changes after human peripheral nerve injury have not been investigated. Consequently, there are no objective measures by which to determine the probability of spontaneous recovery and the optimal timing of surgical intervention. To improve guidance for such decisions, the aim of this study was to characterize morphological changes at the human MEP following traumatic nerve injury.METHODSA prospective cohort (here analyzed retrospectively) of 18 patients with traumatic brachial plexus and axillary nerve injuries underwent biopsy of denervated muscles from the upper extremity from 3 days to 6 years after injury. Muscle specimens were processed for H & E staining and immunohistochemistry, with visualization via confocal and two-photon excitation microscopy.RESULTSImmunohistochemical analysis demonstrated varying degrees of fragmentation and acetylcholine receptor dispersion in denervated muscles. Comparison of denervated muscles at different times postinjury revealed progressively increasing degeneration. Linear regression analysis of 3D reconstructions revealed significant linear decreases in MEP volume (R = −0.92, R2 = 0.85, p = 0.001) and surface area (R = −0.75, R2 = 0.56, p = 0.032) as deltoid muscle denervation time increased. Surprisingly, innervated and structurally intact MEPs persisted in denervated muscle specimens from multiple patients 6 or more months after nerve injury, including 2 patients who had presented > 3 years after nerve injury.CONCLUSIONSThis study details novel and critically important data about the morphology and temporal sequence of events involved in human MEP degradation after traumatic nerve injuries. Surprisingly, human MEPs not only persisted, but also retained their structures beyond the assumed 6-month window for therapeutic surgical intervention based on previous clinical studies. Preoperative muscle biopsy in patients being considered for nerve transfer may be a useful prognostic tool to determine MEP viability in denervated muscle, with surviving MEPs also being targets for adjuvant therapy.

Islamic hedging for pilgrimage funds: case of Indonesia

2019 ◽  
Vol 11 (3) ◽  
pp. 328-341
Author(s):  
Rifki Ismal ◽  
Nurul Izzati Septiana
Keyword(s):  
Exchange Rate ◽  
The Other ◽  
Exchange Rate Risk ◽  
Content Type ◽  
Other Hand ◽  
Rate Risk ◽  
Risk Identify ◽  
Hajj Season ◽  
The Right ◽  
Very High

Purpose The demand for Saudi Arabian real (SAR) is very high in the pilgrimage (hajj) season while the authority, unfortunately, does not hedge the hajj funds. As such, the hajj funds are potentially exposed to exchange rate risk, which can impact the value of hajj funds and generate extra cost to the pilgrims. The purpose of this paper is to conduct simulations of Islamic hedging for pilgrimage funds to: mitigate and minimize exchange rate risk, identify and recommend the ideal time, amount and tenors of Islamic hedging for hajj funds, estimate cost saving by pursuing Islamic hedging and propose technical and general recommendations for the authority. Design/methodology/approach Forward transaction mechanism is adopted to compute Islamic forward between SAR and Rupiah (Indonesian currency) or IDR. Findings – based on simulations, the paper finds that: the longer the Islamic hedging tenors, the better is the result of Islamic hedging, the decreasing of IDR/USD is the right time to hedge the hajj funds and, on the other hand, the IDR/SAR appreciation is not the right time to hedge the hajj funds. Findings Based on simulations, the paper finds that: the longer the Islamic hedging tenors, the better is the result of Islamic hedging, the decreasing of IDR/USD is the right time to hedge the hajj funds and, on the other hand, the IDR/SAR appreciation is not the right time to hedge the hajj funds. Research limitations/implications The research suggests the authority to (and not to) hedge the hajj fund, depending on economic conditions and market indicators. Even though the assessment is for the Indonesian case, other countries maintaining hajj funds might also learn from this paper. Originality/value To the best of author’s knowledge, this is the first paper in Indonesia that attempts to simulate the optimal hedging of hajj funds.

Effects of IDPN-induced axonal swellings on conduction in motor nerve fibers

1985 ◽  
Vol 69 (3) ◽  
pp. 183-200 ◽  
Author(s):  
Elis F. Stanley ◽  
John W. Griffin ◽  
Kenneth E. Fahnestock
Keyword(s):  
Motor Nerve ◽  
Nerve Fibers ◽  
Axonal Swellings

Collaborative design in public services: a wicked problem-reframing case

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patrícia Moura e Sá ◽  
Catarina Frade ◽  
Fernanda Jesus ◽  
Mónica Lopes ◽  
Teresa Maneca Lima ◽  
...  
Keyword(s):  
Collaborative Design ◽  
Success Factors ◽  
Central Government ◽  
Wicked Problem ◽  
Low Density ◽  
Structured Interviews ◽  
Content Type ◽  
Critical Success ◽  
Definition Of ◽  
The Right

PurposeWicked problems require collaborative innovation approaches. Understanding the problem from the users' perspective is essential. Based on a complex and ill-defined case, the purpose of the current paper is to identify some critical success factors in defining the “right problem” to be addressed.Design/methodology/approachAn empirical research study was carried out in a low-density municipality (case study). Extensive data were collected from official databases, individual semi-structured interviews and a focus group involving citizens, local authorities, civil servants and other relevant stakeholders.FindingsAs defined by the central government, the problem to be addressed by the research team was to identify which justice services should be made available locally to a small- and low-density community. The problem was initially formulated using top-down reasoning. In-depth contact with citizens and key local players revealed that the lack of justice services was not “the issue” for that community. Mobility constraints and the shortage of economic opportunities had a considerable impact on the lack of demand for justice services. By using a bottom-up perspective, it was possible to reframe the problem to be addressed and suggest a new concept to be tested at later stages.Social implicationsThe approach followed called attention to the importance of listening to citizens and local organisations with a profound knowledge of the territory to effectively identify and circumscribe a local problem in the justice field.Originality/valueThe paper highlights the limitations of traditional rational problem-solving approaches and contributes to expanding the voice-of-the-customer principle showing how it can lead to a substantially new definition of the problem to be addressed.

Lumbosacral intersegmental epispinal axons and ectopic ventral nerve rootlets

1987 ◽  
Vol 67 (2) ◽  
pp. 269-277 ◽  
Author(s):  
Wesley W. Parke ◽  
Ryo Watanabe
Keyword(s):  
Nerve Root ◽  
Sensory Nerve ◽  
Conus Medullaris ◽  
Spinal Nerve ◽  
Nerve Fibers ◽  
Ventral Horn ◽  
Spinal Nerve Roots ◽  
Nerve Roots ◽  
Content Type ◽  
Almost All

✓ An epispinal system of motor axons virtually covers the ventral and lateral funiculi of the human conus medullaris between the L-2 and S-2 levels. These nerve fibers apparently arise from motor cells of the ventral horn nuclei and join spinal nerve roots caudal to their level of origin. In all observed spinal cords, many of these axons converged at the cord surface and formed an irregular group of ectopic rootlets that could be visually traced to join conventional spinal nerve roots at one to several segments inferior to their original segmental level; occasional rootlets joined a dorsal nerve root. As almost all previous reports of nerve root interconnections involved only the dorsal roots and have been cited to explain a lack of an absolute segmental sensory nerve distribution, it is believed that these intersegmental motor fibers may similarly explain a more diffuse efferent distribution than has previously been suspected.

Evaluation of β-Adrenerglc Blocking Agents in Presence of Adrenergic Tone

1972 ◽  
Vol 50 (5) ◽  
pp. 381-388
Author(s):  
Victor Elharrar ◽  
Reginald A. Nadeau
Keyword(s):  
Dose Response ◽  
Sinus Node ◽  
Stellate Ganglion ◽  
Sodium Pentobarbital ◽  
Response Curves ◽  
Chronotropic Response ◽  
Blocking Agents ◽  
Sinus Node Artery ◽  
Anesthetized Dogs ◽  
The Right

The importance of the level of adrenergic tone in the determination of the dose–response curve to noradrenaline (NA) and in the evaluation of β-adrenergic blocking agents was studied in open-chest sodium pentobarbital anesthetized dogs by injecting drugs directly into the sinus node artery. Changes in the level of adrenergic tone by stimulating the right stellate ganglion resulted in variation of the observed chronotropic response to NA and of its ED50. The chronotropic responses were corrected by taking into account the underlying adrenergic tone. The negative chronotropic effect of dl-propranolol (1 and 10 μg) appeared to be related to its β-blocking properties and not to its quinidine-like effects as shown by the lack of effect of d-propranolol injected at the same doses. The magnitude of the negative chronotropic effects of 10 μg of propranolol and 100 μg of practolol, oxprenolol, and sotalol was shown to be related to the initial heart rate and consequently to the level of adrenergic tone. The comparison of these four β-blocking agents was carried out on corrected dose-response curves to NA. Their relative potencies were found to be: propranolol > oxprenolol > practolol > sotalol, corresponding to ratios of 1, [Formula: see text], [Formula: see text], and [Formula: see text]

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