Intracutaneous Stimulation Research Articles

α-hemihydrate calcium sulfate/octacalcium phosphate combined with sodium hyaluronate promotes bone marrow-derived mesenchymal stem cell osteogenesis in vitro and in vivo.

PurposeThe aims of this research were to combine α-hemihydrate calcium sulfate/octacalcium phosphate (α-CSH/OCP) with sodium hyaluronate (SH) or SH sulfate (SHS) to determine whether these composites can be used as a new type of bone repair material. This study may provide a theoretical basis and new ideas for the construction of active bone repair materials and their clinical application.MethodsIn this study, we combined α-CSH/OCP with SH or SHS. Scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and the wettability test were performed, and porosity, setting time, in vitro degradation, and the mechanical properties of these composite materials were analyzed to evaluate the ultrastructural and physicochemical properties. We evaluated the histocompatibility of these composites by MTT assay, hemolysis, acute toxicity, and pyrogenic and intracutaneous stimulation tests. In addition, the osteogenic differentiation ability of these materials was detected in vitro using Western blot analysis and in vivo using an animal model of bone defect.ResultsThe α-CSH/OCP/SH composite had a compressive strength of 13.72 MPa, a porous rate of 27.45%, and the 28-day degradation rate of 64%. The MTT assay results showed that the relative proliferation rates of the α-CSH/OCP/SH group were greater than 90%. The results of the α-CSH/OCP/SH composite in the hemolysis, acute toxicity, pyrogenic, and intracutaneous stimulation tests were within the normal range. Western blot analysis indicated that the expression of bone extracellular matrix (ECM) proteins was notably upregulated and always higher in the α-CSH/OCP/SH group than in the other groups. XRD of the rabbit radius-defect model indicated that bone healing in the area implanted with α-CSH/OCP/SH was excellent approximately 9 weeks after repair.Conclusionα-CSH/OCP/SH has very good biocompatibility and exhibits clear advantages in the induction of bone regeneration and self-repair, and this compound shows promise in the field of bone tissue engineering.

Microspheres of Carboxymethyl Chitosan, Sodium Alginate, and Collagen as a Hemostatic Agent in Vivo

In the search for biocompatible composite microspheres to be used as a hemostatic agent, in a previous study, we designed a novel biomaterial, consisting of composite microspheres containing three natural biological ingredients, carboxymethyl chitosan, sodium alginate and collagen (CSCM). Furthermore, the chemical and physical properties, hemostatic ability, biocompatibility and cytotoxicity were investigated in vitro. In this work, the in vivo hemostatic performance, wound healing, hemocompatibility, histocompatibility, and biodegradability were evaluated by a series of experiments. The results showed that CSCM could both stop bleeding and enhance healing efficiency by accelerating the clotting and the wound closure rate, suggesting that CSCM acts as a hemostat, and enhances wound healing. In addition, the CSCM material had negligible intracutaneous stimulation reactions and no obvious hemolytic reactions. More importantly, CSCM can be degraded in vivo without significant impacts on physiology, biochemistry, and organization. Thus, CSCM may be a useful tool to stop bleeding in emergency conditions in both military and civilian settings.

Cellulose/soy protein isolate composite membranes: evaluations of in vitro cytocompatibility with Schwann cells and in vivo toxicity to animals.

To evaluate the in vitro cytocompatibility of cellulose/soy protein isolate composite membranes (CSM) with Schwann cells and in vivo toxicity to animals. A series of cellulose/soy protein isolate composite membranes (CSM) were prepared by blending, solution casting and coagulation process. The cytocompatibility of the CSM to Schwann cells were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and by direct cells culture of Schwann cells on the surfaces of the CSM, respectively. The in vivo toxicity of the CSM to animals were also evaluated by acute toxicity testing, skin sensitization testing, pyrogen testing and intracutaneous stimulation testing, respectively, according to the ISO 10993 standard. The MTT assay showed that the cell viability of Schwann cells cultured in extracts from the CSM was higher than that from the neat cellulose membrane without containing SPI component. The direct cells culture indicated that the Schwann cells could attach and grow well on the surface of the CSM and the incorporation of SPI into cellulose contributed to improvement of cell adhesion and proliferation. The evaluations of in vivo biological safety suggested that the CSM showed no acute toxicity, no skin sensitization and no intracutaneous stimulation to the experimental animals. The CSM had in vitro cytocompatibility with Schwann cells and biological safety to animals, suggesting potential for the applications as nerve conduit for the repair of nerve defect.

Pain Ratings and Somatosensory Evoked Responses to Repetitive Intramuscular and Intracutaneous Stimulation in Fibromyalgia Syndrome

To determine the presence of perceptual sensitization and related brain responses we examined 15 patients with fibromyalgia syndrome and 15 healthy controls comparable in age and sex. Multichannel EEG recordings and pain ratings were obtained during the presentation of 800 painful electrical intramuscular and intracutaneous stimuli to the left m. erector spinae and the left m. extensor digitorum. The stimulus intensity was adjusted to 50% between pain threshold and tolerance. Detection and pain thresholds were significantly lower in the fibromyalgia syndrome group. Sensitization occurred for both groups during intramuscular stimulation. In the EEG data the fibromyalgia syndrome patients showed higher N80 amplitudes compared with the healthy controls. Arm stimulation and intramuscular stimulation yielded higher N80 and N150 amplitudes compared with intracutaneous stimulation or stimulation of the back. These results indicate lower pain thresholds in the fibromyalgia syndrome patients after electrical stimulation and a higher N80 amplitude both indicative of enhanced sensory processing in this group.

Brain Activation during Input from Mechanoinsensitive versus Polymodal C-Nociceptors

C-nociceptors mediating cutaneous pain in humans can be distinguished in mechano-heat-responsive units (CMH) and mechano-insensitive units (CMi). However, if sensitized in damaged tissue, CMi play an important role in inflammatory pain. CMi differ from CMH by higher electrical thresholds and by mediating the axon reflex. Using these properties, we established two stimulation paradigms: (1) transcutaneous stimulation (TCS) of low current density below the CMi threshold and (2) intracutaneous stimulation (ICS) of high current density that excites CMi. This was proven by the quantification of the axon-reflex flare. Applying these stimulation paradigms during functional magnetic resonance imaging, we investigated whether nociceptor stimulation that recruits CMi leads to different cerebral activation than stimuli that do not recruit CMi. Brain activation by CMi was inferred by subtraction. Both stimuli recruited multiple afferents other than CMi, and we expected a common network of regions involved in different aspects of pain perception and motor nocifensive reactions in both stimuli. ICS that additionally recruited CMi should activate regions with low acuity that are involved in pain memory and emotional attribution. Besides a common network of pain in both stimuli, TCS activated the supplementary motor area, motor thalamic nuclei, the ipsilateral insula, and the medial cingulate cortex. These regions contribute to a pain processing loop that coordinates the nocifensive motor reaction. CMi nociceptor activation did not cause relevant activation in this loop and does not seem to play a role in withdrawal. The posterior cingulate cortex was selectively activated by ICS and is apparently important for the processing of inflammatory pain.

The unpleasantness of tonic pain is encoded by the insular cortex

Muscle pain differs from skin pain with respect to quality, accuracy of localization, and unpleasantness. This study was conducted to identify the brain regions associated with the affective-motivational component of tonic skin and muscle pain. Forty healthy volunteers were investigated in three groups with different F-18 fluorodeoxyglucose PET activation scans. A verbal rating scale (VRS) was used to quantify pain intensity and unpleasantness. One group was investigated during painful infusion of an acidified phosphate buffer (pH 5.2) into either muscle or skin for 30 minutes. Muscle and skin infusions were adjusted to achieve pain intensity rating of VRS = 40. The second group received sham stimulation of muscle and skin by infusion of non-acidified phosphate buffer (pH 7.3 to 7.4, pain intensity = 0). The third group underwent only one PET scan without sensory stimulation. Unpleasantness ratings were higher (VRS 38.3 vs 25.5) during IM compared to intracutaneous stimulation, despite the same pain intensity (VRS = 40). Sham stimulation revealed no pain or unpleasantness. Regional cerebral glucose metabolism during sham stimulation showed similar findings for intracutaneous and IM infusions with significant activations of the bilateral anterior cingulate, bilateral frontal (premotor) cortex, and the ipsilateral parietal operculum. The comparison of pain vs sham stimulation revealed activations of the bilateral insula for IM but not intracutaneous stimulation. The unpleasantness perception in skin and muscle stimulation was positively correlated to the bilateral insular metabolism. The data suggest that the insula represents one main structure where the unpleasantness of tonic pain perception is encoded.

Skin microcirculation in patients with type I diabetes with and without neuropathy after neurovascular stimulation.

1. Neurovascular inflammation is impaired in patients suffering from diabetic neuropathy. The aim of our study was to evaluate the distribution of nutritive and total skin blood flow in diabetic patients with and without neuropathy after neurovascular stimulation with acetylcholine. 2. Twenty patients with Type I diabetes, 10 with and 10 without neuropathy, and 10 age-matched non-diabetic control subjects, underwent microvascular investigations before and after neurovascular stimulation by intracutaneous application of acetylcholine. The capillary blood cell velocity in the nailfold of the hallux was measured by videophotometric capillaroscopy, and the total skin microcirculation in the same area by laser Doppler flowmetry. 3. The increase in total skin blood flow was significantly impaired in the group of neuropathic diabetic patients compared with the non-neuropathic diabetic patients (17.5 +/- 8.3 versus 51.0 +/- 16.2; P < 0.05) and the non-diabetic subjects (17.5 +/- 8.3 versus 67.8 +/- 19.7; P < 0.01). The increase in capillary blood flow was not significantly impaired in Type I diabetes patients with neuropathy. 4. The ratio between capillary blood flow and total skin perfusion decreased significantly in the control group (from 0.82 +/- 0.15 to 0.47 +/- 0.11; P < 0.05) and in the Type I diabetes patients without neuropathy (from 0.79 +/- 0.12 to 0.43 +/- 0.12; P < 0.05), whereas the decrease in the neuropathic group was statistically insignificant (from 1.05 +/- 0.19 to 0.72 +/- 0.16). 5. Diminished total skin perfusion in the foot after intracutaneous stimulation with acetylcholine in Type I diabetes patients is associated with diabetic neuropathy, indicating a disturbance in the neurovascular reflex arc. This impaired neurovascular response is caused by a diminished total and subpapillary blood flow and not by a diminished nutritive capillary flow. There is no evidence of a diminished nutritive capillary blood flow during neurogenic inflammation in Type I diabetes patients suffering from diabetic neuropathy.

Evoked Cerebral Potentials following Electrical Intracutaneous Stimulation. A Correlate of Pain?

Evoked Cerebral Potentials following Electrical Intracutaneous Stimulation. A Correlate of Pain?

当皮膚科教室における低周波置針療法

Three methods of acupuncture treatment were tried for 72 cases of Herpes zoster (HZ) resisting against usual treatments. One of them was the low-frequency electrical stimulation given between two meridian points on whole body. This was carried out in 35 cases and exerted an exellent beneficial effect on 5 cases, a moderate effect on 18cases, a slight effect on 10 cases and no effect on 2 cases. One of the others was the low-frequency electrical stimulation given between bilateral meridian points on the ears. This was carried out in 15 cases and showed an exellent effect on 7 cases, a moderate effect on 6 cases and a slight effect on 2 cases. The oter was the intracutaneous stimulation with ring-needles for the same meridian points as those of the second. This was carried out in 22 cases and exerted an exellent effect on 9 cases, a moderate effect on 11 cases, a slight effect on 1 case and no effect on 1 case.The same methods were used in 7 cases of postherpe tic neuralgia (PHN). by which complete cure was gained in 3 cases of them.Twenty five cases of Progressive Syste mic Sclerosis (PSS) were treated once or twice a week.13 to 167 times in total, by the low-frequency electrical acupuncture method in the period of 3 months to 3 years and 2 months.Low-frequency electrical stimulation was given between two meridian points (Hatija and Shkai, insome cases Hap' pue and Ashi no sanri of the clinically worse side) for 20 or 30 minutes by using Neurometer NA-J, Pulse Generator N-401, G6805 (made in China) etc.As the result of this treatment, various degrees of improvement in ulcerations on the fingertips or toetips, arthralgia, cutaneous sclerosis, hypo-and hyperpigmentation a nd sensory disturbance etc were obtained and various degrees of improvement in respiratory function, pletysmography, capillary microscopic features of the nailbeds and histopathologicfeatures of the forearm were obtained.Serum ZTT and TTT titers and the res ults of proteinelectrophoresis were recoveredto normal limits aftr more than 100 times of acupuncture in all cases.

Patterned response of lamina V cells: Cutaneous and dorsal funicular stimulation

Single unit activity was recorded in spinal lamina V (LV) in unanesthetized cats. Poststimulus-time histogram (PSTH) analysis of responses to intracutaneous stimulation demonstrated similar firing patterns for all cells. In addition to a direct relationship between stimulus intensity and the duration of cellular response, modulation of firing frequency and distinct delayed PSTH peaks in 77 percent of the units were observed. The pattern of delayed peaks was associated with the same high intensity intracutaneous stimulation reported as painful when applied to human observers. A background of dorsal funicular stimulation selectively inhibited the delayed response of LV cells to high intensity stimulatin. Thus, LV cells, by their duration of firing, transmit information related to stimulus intensity, and, by their patterned responses, have the potential to relay other information, possibly related to their nociceptive role. As delayed LV activity is associated with a high proportion of small fibers in the afferent input, presynaptic inhibition of A-δ and C fibers might account for the selective inhibition associated with dorsal funicular stimulation.