scholarly journals Changes in Hind Paw Epidermal Thickness, Peripheral Nerve Distribution and Mechanical Sensitivity After Immobilization in Rats

2012 ◽  
pp. 643-647 ◽  
Author(s):  
J. NAKANO ◽  
Y. SEKINO ◽  
Y. HAMAUE ◽  
J. SAKAMOTO ◽  
T. YOSHIMURA ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Ankle Joint ◽  
Time Course ◽  
Glabrous Skin ◽  
Epidermal Thickness ◽  
Mechanical Sensitivity ◽  
Histological Changes ◽  
Mechanical Hypersensitivity ◽  
And Control ◽  
Plaster Casts

This study was designed to investigate histological changes in skin tissue accompanying immobilization-induced hypersensitivity. Changes in mechanical sensitivity, epidermal thickness, and peripheral nerve profiles in the upper dermis were examined in glabrous skin of rat hind paw after 1, 2, and 4 weeks of ankle joint immobilization by plaster casts. Induction of mechanical hypersensitivity was confirmed after 2 and 4 weeks of joint immobilization. Epidermal thinning and increase in peripheral nerve profiles were observed in skin tissues in immobilized rats. The time course of epidermal thinning and increase in peripheral nerve profiles were similar closely to that of hypersensitivity, with significant differences between the immobilized and control rats after 2 weeks of immobilization, which became even more remarkable at 4 weeks of immobilization. These findings suggest that joint immobilization by cast induces epidermal thinning and increases peripheral nerve profiles in the upper dermis and that these changes might be partly responsible for immobilization-induced hypersensitivity.

scholarly journals Hindlimb Suspension Does Not Influence Mechanical Sensitivity, Epidermal Thickness, and Peripheral Nerve Density in the Glabrous Skin of the Rat Hind Paw

2013 ◽  
pp. 119-123 ◽  
Author(s):  
Y. TANAKA ◽  
J. NAKANO ◽  
Y. HAMAUE ◽  
Y. SEKINO ◽  
J. SAKAMOTO ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Wistar Rats ◽  
Serum Levels ◽  
Hindlimb Suspension ◽  
Control Group ◽  
Epidermal Thickness ◽  
Mechanical Sensitivity ◽  
Mechanical Hypersensitivity ◽  
Male Wistar Rats ◽  
Von Frey Filaments

Our aim was to investigate the influence of microgravity on the sensitivity of the skin to mechanical stimulation, epidermal thickness, peripheral nerve density in the upper dermis, and serum levels of a stress marker in a rat hindlimb suspension (HS) model. Thirty 8-week-old male Wistar rats were randomly divided into 3 groups: HS, n=10; sham HS, n=10; control, n=10. The suspension system was attached to rat tails in both the HS and sham-HS groups, but the hindlimbs were suspended only in the HS group. The HS and sham-HS groups were treated for 4 weeks. In behavioral tests using von-Frey filaments (n=5 in each group), mechanical hypersensitivity developed in the HS and sham HS groups. Serum corticosterone levels increased significantly in the HS and sham HS groups compared to the control group, and no changes in epidermal thickness or peripheral nerve density were observed immediately after the removal of HS (n=5 in each group). These data indicated that the mechanical hypersensitivity observed in the HS group was not caused by microgravity or inactivity, but rather by restraint stress. We suggest that microgravity does not affect skin sensitivity and histology in these animals.

Inflammation Induces Ectopic Mechanical Sensitivity in Axons of Nociceptors Innervating Deep Tissues

2003 ◽  
Vol 90 (3) ◽  
pp. 1949-1955 ◽  
Author(s):  
Geoffrey M. Bove ◽  
Bernard J. Ransil ◽  
Hsi-Chiang Lin ◽  
Jeong-Gill Leem
Keyword(s):  
Peripheral Nerve ◽  
Sensory Neurons ◽  
Dorsal Root ◽  
Time Course ◽  
Spontaneous Discharge ◽  
Primary Sensory Neurons ◽  
Mechanical Sensitivity ◽  
Pain Syndromes ◽  
Sensory Axons ◽  
Conduction Velocities

A variety of seemingly diverse pain syndromes are characterized by movement-induced pain radiating in the distribution of a peripheral nerve or nerve root. This could be explained by the induction of ectopic mechanical sensitivity in intact sensory axons. Here we show that inflammation led to mechanical sensitivity of the axons of a subset of mechanically sensitive primary sensory neurons. Dorsal root recordings were made from 194 mechanically sensitive neurons that innervated deep and cutaneous structures and had C, Aδ, and Aαβ conduction velocities. No axons of any category were mechanically sensitive in control experiments. However, the axons of neurons innervating deep structures and having C- or Aδ-conduction velocities became mechanically sensitive during the neuritis, and also exhibited an increased incidence of spontaneous discharge. The incidence of mechanical sensitivity followed a distinct time course. In some cases, paw withdrawal thresholds were obtained after neuritis induction. The time course of the resultant hypersensitivity was not directly related to the time course of the axonal mechanical sensitivity. Ectopic axonal mechanical sensitivity could explain some types of radiating, nerve-related pain coexisting with diseases of seemingly diverse etiologies.

scholarly journals Post hoc analysis of ellipsoid zone changes beyond the central subfield in symptomatic vitreomacular adhesion patients from the OASIS trial

2021 ◽  
Vol 6 (1) ◽  
pp. e000648
Author(s):  
Swetha Bindu Velaga ◽  
Muneeswar Gupta Nittala ◽  
Michael S Ip ◽  
Luc Duchateau ◽  
SriniVas R Sadda
Keyword(s):  
Time Course ◽  
Vitreomacular Adhesion ◽  
Ellipsoid Zone ◽  
Post Hoc Analysis ◽  
Link Type ◽  
Phase Iiib ◽  
The Status ◽  
Registration Number ◽  
Post Hoc ◽  
And Control

Background/aimsOASIS is a Phase IIIb trial (NCT01429441) assessing long-term outcomes in subjects with symptomatic vitreomacular adhesion (VMA). The purpose of this study is to report on the frequency, severity, location and time course of ellipsoid zone (EZ) alterations in ocriplasmin-treated and sham control eyes in the OASIS study.Methods220 patients (146 ocriplasmin, 74 sham) subjects with VMA were enrolled in this masked post hoc analysis phase IIIb, randomised, sham-controlled double-masked multicentre clinical trial. A masked post hoc analysis of OCT images was performed at the Doheny Image Reading Center from subjects enrolled in the OASIS trial. The status of the EZ band was assessed in three different macular regions: the central subfield (CS) (≤1 mm diameter), the parafoveal area (PAA) (>1 to ≤3 mm) and the perifoveal area (PEA) (>3 to ≤6 mm). The EZ band was rated as normal/intact, full thickness macular hole (FTMH), abnormal but continuous, discontinuous/disrupted or absent at visits from baseline (pretreatment) to week 1 (day 7), month 1 (day 28), month 3, month 6, month 12 and the final follow-up at month 24. EZ band status was compared in both study and control eyes.ResultsA total of 208 patients (138 ocriplasmin, 70 sham) were included in this analysis. At baseline, FTMH was present in 48.6%, 8.0%, 0% and 52.8%, 2.9%, 0% in the CS, PAA and PEA of the ocriplasmin and sham groups, respectively. The EZ was graded to be abnormal but continuous, discontinuous/disrupted or absent at Baseline in 21.0%, 4.3%, 2.8% in the CS, PAA and PEA, respectively, of the ocriplasmin group; and 12.9%, 10.0%, 4.3% in the CS, PAA and PEA of the sham group. For the ocriplasmin group in the PAA, this frequency increased to 6.6% at week 1, was 9.8% at month 1, but improved to 3.8% at month 3, and remained stable to 1.6% at month 24. These differences, however, were not statistically significant.ConclusionsOcriplasmin treatment for symptomatic VMA was associated with EZ abnormalities in a small percentage of patients that was best assessed in regions (PEA) relatively unaffected by the VM interface disease at baseline. The EZ abnormalities were apparent by week 1, persisted at month 1, and appeared to resolve in the majority of cases by month 3.Trial registration numberNCT01429441

Infused salbutamol accentuates acid-induced lung injury in the rat

1986 ◽  
Vol 71 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Stanley Braude ◽  
David Royston
Keyword(s):  
Lung Injury ◽  
Intravenous Infusion ◽  
Time Course ◽  
Weight Ratio ◽  
Dry Weight ◽  
Adrenergic Agonist ◽  
Lung Water ◽  
Significant Difference ◽  
And Control ◽  
Control Infusion

1. The effect in the rat of salbutamol infusion (1 μg min−1 kg−1) on acid-induced lung injury has been determined. Severity of lung injury was assessed by two techniques: the pulmonary clearance of 99mTc-diethylenetriaminepenta-acetate (99mTc-DTPA) and the lung wet/dry weight ratio, giving indices of alveolar epithelial permeability and transendothelial water filtration respectively. 2. Mean half-time of clearance of 99mTc-DTPA was increased significantly in rats who had intratracheal acid-induced injury and control (saline) intravenous infusion (19.4 ± 2.6 min) compared with non-acid-treated rats (98.1 ± 7.2) (P < 0.0001). However, those animals who had intratracheal acid injury and subsequent salbutamol intravenous infusion had significantly faster clearance (11.5 ± 1.9) than the acid and control infusion group (P < 0.05). 3. Gravimetric lung water in the acid-only rats (expressed as wet/dry weight ratio) was increased significantly (6.4 ± 0.3) compared with the non-acid-treated controls (5.4 ± 0.2) (P < 0.01). Acid-treated rats who had salbutamol infused had dramatically increased lung water (10.0 ± 0.6) (P < 0.001 vs acid and control infusion). 4. Intravenous salbutamol infusion itself produced no significant difference in the results for both techniques, compared with the non-acid-treated time-course controls. 5. Infused salbutamol accentuates acid-induced lung injury in the rat. Possible factors responsible for these findings include β2-adrenergic agonist mediated inhibition of hypoxic pulmonary vasoconstriction (HPV) and a predominant β1-adrenergic agonist inotropic effect of salbutamol with resultant rise in pulmonary artery pressure.

Selected Contribution: Acute cellular and molecular responses to resistance exercise

2002 ◽  
Vol 93 (1) ◽  
pp. 394-403 ◽  
Author(s):  
Fadia Haddad ◽  
Gregory R. Adams
Keyword(s):  
Resistance Exercise ◽  
Intracellular Signaling ◽  
Time Course ◽  
Compensatory Hypertrophy ◽  
Molecular Responses ◽  
Single Bout ◽  
And Control ◽  
Myogenic Markers ◽  
Rest Intervals

Training protocols apply sequential bouts of resistance exercise (RE) to induce the cellular and molecular responses necessary to produce compensatory hypertrophy. This study was designed to 1) define the time course of selected cellular and molecular responses to a single bout of RE and 2) examine the effects of interbout rest intervals on the summation of these responses. Rat muscles were exposed to RE via stimulation of the sciatic nerve in vivo. Stimulated and control muscles were obtained at various time points post-RE and analyzed via Western blot and RT-PCR. A single bout of RE increased intracellular signaling (i.e., phosphorylations) and expression of mRNAs for insulin-like growth factor-I system components and myogenic markers (e.g., cyclin D1, myogenin). A rest interval of 48 h between RE bouts resulted in much greater summation of myogenic responses than 24- or 8-h rest intervals. This experimental approach should be useful for studying the regulatory mechanisms that control the hypertrophy response. These methods could also be used to compare and contrast different exercise parameters (e.g., concentric vs. eccentric, etc.).

scholarly journals A comparison of two-dimensional and three-dimensional techniques for determining the kinematic patterns for hindlimb obstacle clearance during sheep locomotion.

2020 ◽  
Author(s):  
Camila Cardoso Diogo ◽  
Bárbara Fonseca ◽  
Francisca S.M. Almeida ◽  
Luís Maltez da Costa ◽  
José Eduardo Pereira ◽  
...  
Keyword(s):  
Peripheral Nerve ◽  
Nerve Injury ◽  
Peripheral Nerve Injury ◽  
Time Course ◽  
Objective Assessment ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Ovine Model ◽  
Obstacle Clearance ◽  
Injury And Repair

Abstract Background: Analysis of locomotion is often used as a measure for impairment and recovery following experimental peripheral nerve injury. Compared to rodents, sheep offer several attractive features as an experimental model for studying peripheral nerve regeneration. There are no studies on locomotion outcomes after peripheral nerve injury and repair in the sheep model. In the present study, we performed and compared two-dimensional (2D) and, for the first time, three-dimensional (3D) hindlimb kinematics during obstacle avoidance in the ovine model. This study aimed to obtain kinematic data to serve as a template for an objective assessment of the ankle joint motion in future studies of common peroneal nerve (CP) injury and repair in the ovine model. Results: The strategy used by the sheep to bring the hindlimb over a moderately high obstacle, set to 10% of its hindlimb length, was the pronounced knee, ankle and metatarsophalangeal flexion when approaching and clearing the obstacle. Despite the overall time course kinematic patterns about the hip, knee, ankle, and metatarsophalangeal were identical, we found significant differences between values of the 2D and 3D joint angular motion. Conclusions: Our results show that the most apparent changes that occurred during the gait cycle were for the ankle and metatarsophalangeal joints, whereas the hip and knee joints were much less affected. Data and techniques described here are likely to be useful for an objective assessment of altered gait after CP injury and repair in an ovine model.

scholarly journals NI-11 PATHOLOGICAL ASSESSMENT IN THE IMPACT OF ONE-SHOT BEVACIZUMAB ON UPTAKE OF 11C-METHIONINE

2019 ◽  
Vol 1 (Supplement_2) ◽  
pp. ii27-ii28
Author(s):  
Takaaki Beppu ◽  
Yuichi Sato ◽  
Kuniaki Ogasawara
Keyword(s):  
Amino Acid ◽  
Microvascular Density ◽  
Control Group ◽  
Tumor Removal ◽  
Histological Changes ◽  
Positron Emission ◽  
Newly Diagnosed Glioblastoma ◽  
And Control ◽  
The Impact ◽  
Single Intravenous Administration

Abstract BACKGROUND This study aimed to clarify how one-time administration of bevacizumab (BEV) changes histological features in glioblastoma, and how histological changes affect the uptake of 11C-methyl-L-methionine (11C-met) as an amino-acid tracer. MATERIALS AND METHODS Subjects were 18 patients with newly diagnosed glioblastoma who were assigned to 2 groups: BEV group, single intravenous administration of BEV before surgical tumor removal; and control group, surgical tumor removal alone. After surgery, we compared the densities of tumor cells and microvessels, and microvascular structures including vascular pericytes and L-type amino acid transporter-1 (LAT1), between the BEV and control groups. Correlations between 11C-met uptake on positron emission tomography before surgery, microvascular density, and LAT1 expression were assessed in each group. RESULTS BEV induced significant reductions in microvascular density, while tumor cell density and proliferation were retained in the BEV group. Percentages of vessels with pericytes and vascular endothelium with LAT1 expression were lower in the BEV group than in controls. Uptake of 11C-met correlated significantly with microvascular density in the BEV group, but not with LAT1expression. CONCLUSIONS The present study showed that even one course of BEV administration induced reductions in microvessels, vascular pericytes, and LAT1 expression in glioblastomas. One course of BEV therapy also reduced 11C-met uptake, which might have been largely attributed to reductions in microvessels rather than reductions in LAT1 expression, in addition to reduction of vascular permeability.

scholarly journals A Hyperresponsive HPA Axis May Confer Resilience Against Persistent Paclitaxel-Induced Mechanical Hypersensitivity

2015 ◽  
Vol 18 (3) ◽  
pp. 290-298 ◽  
Author(s):  
Sharon L. Kozachik ◽  
Gayle G. Page
Keyword(s):  
Neuropathic Pain ◽  
Hpa Axis ◽  
Fischer 344 Rats ◽  
Mechanical Sensitivity ◽  
Mechanical Hypersensitivity ◽  
Fischer 344 ◽  
Biological Stress ◽  
Sd Rats ◽  
Stress Responsivity ◽  
Hands And Feet

Paclitaxel (PAC) treatment is associated with persistent, debilitating neuropathic pain that affects the hands and feet. Female sex and biological stress responsivity are risk factors for persistent pain, but it is unclear whether these important biologically based factors confer risk for PAC-induced neuropathic pain. To determine the relative contributions of sex and hypothalamic–pituitary–adrenal (HPA)-axis stress responsivity to PAC-induced mechanical hypersensitivity, we employed a PAC protocol consisting of three, 2-week cycles of every-other-day doses of PAC 1 mg/kg versus saline (Week 1) and recovery (Week 2), totaling 42 days, in mature male and female Fischer 344, Lewis, and Sprague Dawley (SD) rats, known to differ in HPA axis stress responsivity. Mechanical sensitivity was operationalized using von Frey filaments, per the up–down method. Among PAC-injected rats, SD rats exhibited significantly greater mechanical hypersensitivity relative to accumulative PAC doses compared to Fischer 344 rats. Lewis rats were not significantly different in mechanical hypersensitivity from SD or Fischer 344 rats. At the end of the protocol, PAC-injected SD rats exhibited profound mechanical hypersensitivity, whereas the PAC-injected Fischer 344 rats appeared relatively resilient to the long-term effects of PAC and exhibited mechanical sensitivity that was not statistically different from their saline-injected counterparts. Sex differences were mixed and noted only early in the PAC protocol. Moderate HPA axis stress responsivity may confer additional risk for the painful effects of PAC. If these findings hold in humans, clinicians may be better able to identify persons who may be at increased risks for developing neuropathic pain during PAC therapy.

Sign in / Sign up

Export Citation Format

Share Document