Electrical Stimulation of the Vagus Nerve Dermatome in the External Ear is Protective in Rat Cerebral Ischemia

Background Although cervical vagus nerve stimulation is effective for reducing infarct volume in rats, it is not feasible for acute human stroke as it requires surgical incision of the neck. We hypothesized that stimulation of the dermatome in the external ear innervated by the vagus nerve (auricular vagus nerve stimulation; aVNS) reduces infarct volume after transient focal ischemia in rats. Methods Animals were randomized to active aVNS or sham stimulation. For aVNS, electrical stimulation of the left cavum concha (1 hour duration) using percutaneous needles was initiated 30 min after induction of ischemia. Behavioral and tissue outcome were measured 24 hours after induction of ischemia. In a separate experimental dataset, c-Fos immunohistochemistry was performed to identify the brain regions activated after the stimulation. Results Stimulation of the left cavum concha resulted in bilateral c-Fos staining in the nuclei tractus solitarii and the loci coerulei in all animals. There was no c-Fos staining in any part of the brainstem in sham control animals. The mean infarct volume (SD) as calculated by indirect method was 44.20 ± 7.58% in controls and 31.65 ± 9.67% in treated animals (p<0.0001). The effect of aVNS on tissue outcome was associated with better neurological scores at 24 hours after ischemia (p<0.0001). Conclusions Electric stimulation of the vagus nerve dermatome in the external ear activates brainstem afferent vagal nuclei and reduces infarct volume in rats. This finding has potential to facilitate the development of treatments that leverage the brain’s endogenous neuroprotective pathways at the setting of acute ischemic stroke

Optymalizacja parametrów procesu produkcji tkanin flokowanych w celu wyeliminowania problemu braku regeneracji włókien

This study was focused on the elimination of defects due to the non-recovery of bent fibres in flock. For this reason, it was aimed to shorten the recovery time of bent fibres in flock as much as possible by optimising selected process parameters in flocked fabric production. For this aim; the diameter of flock fibre, the flock type, paste type, foam density, presetting, dyeing machine type, finishing treatment type, amount of treatment (finishing chemical), use of the brake mechanism during packing the fabric, and tension during winding were changed in two levels and their effects were investigated statistically. As a result of pareto analysis and statistical evaluations, among the many parameters that may affect this problem, the type of finishing process and presetting were found to have a critical effect. According to the experimental results, it was concluded that the recovery time of bent fibres in flocked fabrics could be significantly shortened if the flocked fabrics are not preset and silicone softener is applied during finishing treatments.W pracy skoncentrowano się na eliminacji defektów wynikających z braku regeneracji włókien podczas flokowania. Z tego powodu starano się maksymalnie skrócić czas regeneracji giętych włókien poprzez optymalizację wybranych parametrów procesu produkcji tkanin flokowanych. W tym celu: zmieniono średnicę włókna flokowego, rodzaj flokowania, rodzaj pasty, gęstość pianki, ustawienia, wstępne, rodzaj maszyny barwiącej, rodzaj obróbki wykańczającej, ilość obróbki (chemia wykańczająca), sposób użycia mechanizmu hamulca podczas pakowania tkaniny oraz naprężenie podczas nawijania na dwóch poziomach, a wyniki poddano analizie statystycznej. W wyniku analizy Pareto i ocen statystycznych, spośród wielu parametrów, które mogą wpływać na omawiany problem, stwierdzono, że rodzaj procesu wykańczania i ustawienia wstępne mają największy wpływ. Na podstawie wyników eksperymentów stwierdzono, że czas regeneracji zagiętych włókien może ulec znacznemu skróceniu, jeśli podczas obróbki wykańczającej zastosowany zostanie zmiękczacz silikonowy

DataSheet1_Short-pulsed micro-magnetic stimulation of the vagus nerve.pdf

Vagus nerve stimulation (VNS) is commonly used to treat drug-resistant epilepsy and depression. The therapeutic effect of VNS depends on stimulating the afferent vagal fibers. However, the vagus is a mixed nerve containing afferent and efferent fibers, and the stimulation of cardiac efferent fibers during VNS may produce a rare but severe risk of bradyarrhythmia. This side effect is challenging to mitigate since VNS, via electrical stimulation technology used in clinical practice, requires unique electrode design and pulse optimization for selective stimulation of only the afferent fibers. Here we describe a method of VNS using micro-magnetic stimulation (µMS), which may be an alternative technique to induce a focal stimulation, enabling a selective fiber stimulation. Micro-coils were implanted into the cervical vagus nerve in adult male Wistar rats. For comparison, the physiological responses were recorded continuously before, during, and after stimulation with arterial blood pressure (ABP), respiration rate (RR), and heart rate (HR). The electrical VNS caused a decrease in ABP, RR, and HR, whereas µM-VNS only caused a transient reduction in RR. The absence of an HR modulation indicated that µM-VNS might provide an alternative technology to VNS with fewer heart-related side effects, such as bradyarrhythmia. Numerical electromagnetic simulations helped estimate the optimal coil orientation with respect to the nerve to provide information on the electric field’s spatial distribution and strength. Furthermore, a transmission emission microscope provided very high-resolution images of the cervical vagus nerve in rats, which identified two different populations of nerve fibers categorized as large and small myelinated fibers.</p

Neonatal Graves' disease occurring in an infant whose mother had a thyroidectomy due to Graves' disease [Graves hastali?i nedeniyle tiroidektomi olan annenin yenido?an bebe?inde Graves hastali?i: Bir vaka takdimi]

Neonatal Graves' disease caused by fetal thyroid gland stimulation is the result of transplacental passage of maternal thyroid-stimulating hormone receptor antibodies in the second trimester of pregnancy. A mother with Graves-Basedow disease had a total thyroidectomy operation three months before a pregnancy; maternal TSH receptor antibody (TRAb) were detected at the sixth month of pregnancy. Antithyroid drug therapy was started to the 34 weeks' gestational age infant, who was diagnosed with neonatal hyperthyroidism. The condition improved after five weeks of antithyroid therapy. The pathogenesis was believed to be due to transplacental passage of maternal TRAb. This case is presented to highlight the fact that even mothers who have a total throidectomy for Graves' disease may have infants with rarely seen neonatal Graves' disease due to the presence of maternal TRAb in the circulation

A Manganese Alternative to Gadolinium for MRI Contrast

Contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) are routinely used to diagnose soft tissue and vascular abnormalities. However, safety concerns limit the use of iodinated and gadolinium (Gd)-based CT and MRI contrast media in renally compromised patients. With an estimated 14% of the US population suffering from chronic kidney disease (CKD), contrast media compatible with renal impairment is sorely needed. We present the new manganese­(II) complex [Mn­(PyC3A)­(H₂O)]⁻ as a Gd alternative. [Mn­(PyC3A)­(H₂O)]⁻ is among the most stable Mn­(II) complexes at pH 7.4 (log <i>K</i>_ML = 11.40). In the presence of 25 mol equiv of Zn at pH 6.0, 37 °C, [Mn­(PyC3A)­(H₂O)]⁻ is 20-fold more resistant to dissociation than [Gd­(DTPA)­(H₂O)]^2–. Relaxivity of [Mn­(PyC3A)­(H₂O)]⁻ in blood plasma is comparable to commercial Gd contrast agents. Biodistribution analysis confirms that [Mn­(PyC3A)­(H₂O)]⁻ clears via a mixed renal/hepatobiliary pathway with >99% elimination by 24 h. [Mn­(PyC3A)­(H₂O)]⁻ was modified to form a bifunctional chelator and 4 chelates were conjugated to a fibrin-specific peptide to give Mn-FBP. Mn-FBP binds the soluble fibrin fragment DD­(E) with <i>K</i>_d = 110 nM. Per Mn relaxivity of Mn-FBP is 4-fold greater than [Mn­(PyC3A)­(H₂O)]⁻ and increases 60% in the presence of fibrin, consistent with binding. Mn-FBP provided equivalent thrombus enhancement to the state of the art Gd analogue, EP-2104R, in a rat model of arterial thrombosis. Mn metabolite analysis reveals no evidence of dechelation and the probe was >99% eliminated after 24 h. [Mn­(PyC3A)­(H₂O)]⁻ is a lead development candidate for an imaging probe that is compatible with renally compromised patients