Spatial and temporal codes mediate the tactile perception of natural textures.

When we run our fingers over the surface of an object, we acquire information about its microgeometry and material properties. Texture information is widely believed to be conveyed in spatial patterns of activation evoked across one of three populations of cutaneous mechanoreceptive afferents that innervate the fingertips. Here, we record the responses evoked in individual cutaneous afferents in Rhesus macaques as we scan a diverse set of natural textures across their fingertips using a custom-made rotating drum stimulator. We show that a spatial mechanism can only account for the processing of coarse textures. Information about most natural textures, however, is conveyed through precise temporal spiking patterns in afferent responses, driven by high-frequency skin vibrations elicited during scanning. Furthermore, these texture-specific spiking patterns predictably dilate or contract in time with changes in scanning speed; the systematic effect of speed on neuronal activity suggests that it can be reversed to achieve perceptual constancy across speeds. The proposed temporal coding mechanism involves converting the fine spatial structure of the surface into a temporal spiking pattern, shaped in part by the mechanical properties of the skin, and ascribes an additional function to vibration-sensitive mechanoreceptive afferents. This temporal mechanism complements the spatial one and greatly extends the range of tangible textures. We show that a combination of spatial and temporal mechanisms, mediated by all three populations of afferents, accounts for perceptual judgments of texture.

Low-level laser irradiation stimulates tenocyte proliferation in association with increased NO synthesis and upregulation of PCNA and cyclins.

Low-level laser therapy is commonly used to treat tendinopathy or tendon injury. Tendon healing requires tenocyte migration to the repair site, followed by proliferation and synthesis of the extracellular matrix. There are few evidence to elucidate that low-level laser promote tenocyte proliferation. This study was designed to determine the effect of laser on tenocyte proliferation. Furthermore, the association of this effect with secretion of nitric oxide (NO) and the expressions of proliferating cell nuclear antigen (PCNA) and cyclins D1, E, A, and B1 was investigated. Tenocytes intrinsic to rat Achilles tendon were treated with low-level laser (660 nm). Tenocyte proliferation was evaluated by MTT assay and immunocytochemistry with Ki-67 stain. NO in the conditioned medium was measured by ELISA. Western blot analysis was used to evaluate the protein expressions of PCNA and cyclins D1, E, A, and B1. The results revealed that tenocytes proliferation was enhanced dose dependently by laser. NO secretion was increased after laser treatment. PCNA and cyclins E, A, and B1 were upregulated by laser. In conclusion, low-level laser irradiation stimulates tenocyte proliferation in a process that is mediated by upregulation of NO, PCNA, and cyclins E, A, and B1.

Carpal Tunnel Syndrome in Elite Female Tug-of-War Athletes: Prevalence and Risk Factor Analysis.

Background: Tug-of-War (TOW) games involve repetitive hand movements and vigorous force, raising the risk of peripheral neuropathy in the upper extremities. The prevalence of carpal tunnel syndrome (CTS) in TOW athletes remains unclear. We hypothesize that elite female TOW athletes have a higher prevalence of CTS than the general population. Methods: Twenty-nine female TOW athletes were recruited from a national team and participated in the study. CTS was clinically diagnosed by history taking and physical examination. Nerve conduction studies (NCS) were additionally performed to confirm CTS. Results: Twelve athletes were clinically diagnosed with CTS; however, only nine were confirmed by NCS. Ten athletes were diagnosed with subclinical CTS by NCS, while seven were classified as truly-non-CTS by both clinical assessment and NCS. The prevalence of CTS and subclinical CTS among the athletes was found to be 33.3% and 37.0%, respectively, significantly higher than 2.7% in the general population by electrodiagnosis. The body weight (p = 0.025) of the athletes with CTS and subclinical CTS was significantly different from those of the athletes without CTS. Conclusions: Our observations revealed a higher prevalence of CTS among elite female TOW athletes, with body weight being a risk factor. The forceful grasping and pulling of the rope may contribute to the development of CTS.

Comparing the effects of isoflurane and pentobarbital on the responses of cutaneous mechanoreceptive afferents.

BACKGROUND: While pentobarbital has been used extensively in neurophysiological experiments investigating activity in peripheral nerves, it has fallen out of favor as an anesthetic because of safety concerns and is often replaced with isoflurane. However, the effects of isoflurane on the excitability of mechanoreceptive afferents have yet to be conclusively elucidated. METHODS: To fill this gap, we collected extracellular single-unit recordings of cutaneous mechanoreceptive afferents from the sciatic nerve of 21 rats during vibratory stimulation of the hindpaw. We then compared the strength and temporal structure of the afferent response measured under pentobarbital and isoflurane anesthesia. RESULTS: We found that the strength and temporal structure of afferent responses were statistically equivalent whether these were evoked under isoflurane or pentobarbital. CONCLUSIONS: We conclude that, if these two anesthetics have any effect on the responses of mechanoreceptive afferents, their effects are indistinguishable.

High glucose concentration up-regulates the expression of matrix metalloproteinase-9 and -13 in tendon cells.

BACKGROUND: Diabetes mellitus is associated with tendinopathy or tendon injuries. However, the mechanism underlying diabetic tendinopathy is unclear. The purpose of this study was to examine the effects of high glucose concentrations on the activity and expression of matrix metalloproteinases, type I collagen, and type III collagen in tendon cells. METHODS: Tendon cells from rat Achilles tendons were treated with 6 mM, 12 mM, and 25 mM glucose, and then cell proliferation was evaluated by the 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Messenger RNA (mRNA) expression of MMP-2, MMP-8, MMP-9, and MMP-13 and type I and type III collagen was assessed by quantitative real-time polymerase chain reaction (PCR). The enzymatic activity of MMP-2 and MMP-9 was measured by gelatin zymography. RESULTS: The MTT assay results showed that the glucose concentration did not affect tendon cell proliferation. The results of the real-time PCR assay revealed that the mRNA expression of MMP-9 and MMP-13 was up-regulated by treatment with 25 mM glucose, whereas the mRNA expression of type I and III collagen was not affected. Gelatin zymography showed that 25 mM glucose increased the enzymatic activity of MMP-9. CONCLUSIONS: High glucose concentration up-regulates the expression of MMP-9 and MMP-13 in tendon cells, which may account for the molecular mechanisms underlying diabetic tendinopathy.

Reproducibility of sonographic measurement of thickness and echogenicity of the plantar fascia.

BACKGROUND: To evaluate the intra- and interrater reliability of ultrasonographic measurements of the thickness and echogenicity of the plantar fascia. METHODS: Eleven patients (20 feet), who complained of inferior heel pain, and 26 volunteers (52 feet) were enrolled. Two sonographers independently imaged the plantar fascia in both longitudinal and transverse planes. Volunteers were assessed twice to evaluate intrarater reliability. Quantitative evaluation of the echogenicity of the plantar fascia was performed by measuring the mean gray level of the region of interest using Digital Imaging and Communications in Medicine viewer software. RESULTS: Sonographic evaluation of the thickness of the plantar fascia showed high reliability. Sonographic evaluations of the presence or absence of hypoechoic change in the plantar fascia showed surprisingly low agreement. The reliability of gray-scale evaluations appears to be much better than subjective judgments in the evaluation of echogenicity. Transverse scanning did not show any advantage in sonographic evaluation of the plantar fascia. CONCLUSIONS: The reliability of sonographic examination of the thickness of the plantar fascia is high. Mean gray-level analysis of quantitative sonography can be used for the evaluation of echogenicity, which could reduce discrepancies in the interpretation of echogenicity by different sonographers. Longitudinal instead of transverse scanning is recommended for imaging the plantar fascia.

The effects of aging on quantitative sonographic features of rotator cuff tendons.

PURPOSE: Grayscale analysis is a practical, objective, and easy way to quantify echogenicity during ultrasonography. The purpose of the current study was to measure the changes in thickness and echogenicity that result from aging of the rotator cuff and long head of the biceps tendons. METHODS: The study comprised 45 volunteers, aged between 20 and 84 years and without history of shoulder pain. Participants were divided into three groups: young, middle-aged, and old. All subjects underwent standard ultrasonography of both shoulders. Tendon thickness and tear were recorded, and images in both transverse and longitudinal scans were taken for grayscale analysis. To reduce the attenuation effect from skin and subcutaneous fat, we used the ratio of echogenicity of the tendon to that of the reference muscle and compared the tendon echogenicity among the different age groups. Sonographic findings were also correlated with age. RESULTS: The supraspinatus tendon was significantly thicker in elderly participants and this was positively correlated with age. Moreover, the echogenicity ratio of the supraspinatus tendon decreased in the elderly group and showed a negative correlation with age. There was a higher prevalence of supraspinatus tendon tears in the older participants. CONCLUSIONS: Our results indicate that supraspinatus tendons became thickened, hypoechogenic, and more likely to tear with age. The study presents a simple and useful method to investigate the echogenicity of the rotator cuff quantitatively.

Platelet-Rich Plasma Releasate Promotes Early Healing in Tendon After Acute Injury.

BACKGROUND: Acute tendon injury can limit motion and thereby inhibit tendon healing. Positive results have been found after the use of platelet-rich plasma (PRP) to treat tendon injury; however, the early effects of PRP on tendon regeneration are not known. PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate the effects of PRP releasate (PRPr) on the early stages of tendon healing in a rat partial tenotomy model. It was hypothesized that PRPr can promote early healing of an Achilles tendon in rats. STUDY DESIGN: Controlled laboratory study. METHODS: PRP was prepared by a 2-step method of manual platelet concentration from 10 rats. PRPr was isolated from the clotted preparation after activation by thrombin and was applied to an Achilles tendon on 1 side of 30 rats on the second day after partial tenotomy, with normal saline used as the control on the other side. Achilles tendon samples were harvested 5 and 10 days after tenotomy. At each time point, 15 Achilles tendon samples were obtained, of which 5 samples were evaluated by Masson trichrome staining, apoptosis, and cell proliferation, while the other 10 samples were tested for tensile strength using a material testing machine. RESULTS: Compared with saline-treated control tendons, the PRPr-treated tendons showed increased collagen synthesis near the cut edge and fewer apoptotic cells (P = .01). An immunohistochemical analysis revealed more Ki-67-positive cells but fewer cluster of differentiation (CD) 68+ (ED1+) macrophages in PRPr tendons compared with saline-treated tendons (P < .01). Tendons treated with PRPr also showed higher ultimate tensile strength than those treated with saline (P = .03). CONCLUSION: PRPr treatment promotes tissue recovery in the early phase of tendon healing by stimulating tendon cell proliferation and collagen production while inhibiting cell apoptosis and CD68+ (ED1+) macrophage infiltration. CLINICAL RELEVANCE: These findings suggest that with PRPr treatment, higher loads can be applied to the healing tendon at an earlier time, which can help the patient resume activity earlier.

Transperineal injection of botulinum toxin A for treatment of detrusor sphincter dyssynergia: localization with combined fluoroscopic and electromyographic guidance.

OBJECTIVE: To determine the effectiveness of a combined method for localizing external urethral sphincter for transperineal injection of botulinum toxin A (BTX-A) in the treatment of detrusor sphincter dyssynergia (DSD) in patients with spinal cord injury (SCI). DESIGN: A prospective, open-label trial. SETTING: A rehabilitation hospital affiliated with a medical university. PARTICIPANTS: Eighteen SCI patients with voiding dysfunction resulting from urodynamically confirmed DSD. INTERVENTIONS: 100 units of BTX-A injected transperineally into the external urethral sphincter, which was localized using combined fluoroscopic and electromyographic guidance, using a Foley catheter inserted for visualization of vesicourethral anatomy. MAIN OUTCOME MEASURES: (1) postvoid residual volume, (2) leak point pressure, (3) maximal intravesical pressure, (4) maximal urethral pressure, (5) quality of life measures for urination, quantified by the Quality of Life Index (QLI). RESULTS: Positive clinical outcomes were observed in all 18 patients in this study. The mean reductions in postvoid residual volume, leak point pressure, maximal intravesical pressure, and maximal urethral pressure before and after BTX-A injection were 183ml, 37cm H2O, 45cm H2O, and 92cm H2O, respectively (all P values <.05). The mean QLI significantly improved from -0.68+/-0.27 to 0.66+/-0.19 (P<.01). No significant side effects were noted after injection. The clinical therapeutic effects have shown reductions in occurrence and degree of autonomic dysreflexia, vesicoureteral reflux, hydronephrosis, and urinary tract infection. The bladder management programs also obtained improvements in our patients, either doing intermittent catheterizations less frequently, or resuming spontaneous voiding without indwelling catheters. CONCLUSION: With this combined method for localization of the external urethral sphincter, transperineal injection of BTX-A was safe, accurate, easy to perform, and effective for treatment of DSD in patients with SCI.

Autologous Blood-Derived Products Compared With Corticosteroids for Treatment of Plantar Fasciopathy: A Systematic Review and Meta-Analysis.

OBJECTIVE: This review article evaluated the efficacy of autologous blood-derived products, including whole blood and platelet-rich plasma, in reducing pain and improving function compared with corticosteroids for plantar fasciopathy patients. DESIGN: Literature comparing autologous blood-derived product and corticosteroids for the treatment of plantar fasciopathy was systematically reviewed. Twelve randomized controlled trials and four quasi-experimental studies were included. The visual analog scale pain score and American Orthopedic Foot and Ankle Society hindfoot score were evaluated at 1.5, 3, and 6 mos' follow-up. Subgroup analyses were performed concerning platelet-rich plasma preparation techniques, injection regiments, and study designs. RESULTS: Corticosteroids were found to reduce pain more effectively than whole blood at 1.5 and 3 mos, but the effect disappeared at 6 mos. Platelet-rich plasma reduced pain more effectively at 6 mos' postinjection than corticosteroids. However, there was no significant difference in the American Orthopedic Foot and Ankle Society score between platelet-rich plasma and corticosteroids injections at any time point. In the subgroup analyses, pain was significantly reduced at 6 mos by self-prepared platelet-rich plasma, one-step separation platelet-rich plasma, platelet-rich plasma of more than 3 ml, and platelet-rich plasma without local analgesics. CONCLUSIONS: The results of this meta-analysis suggest that platelet-rich plasma may provide a long-term effect in relieving pain in plantar fasciopathy patients. TO CLAIM CME CREDITS: Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES: Upon completion of this article, the reader should be able to: (1) Compare the efficacy of whole blood (WB), platelet-rich plasma (PRP), and corticosteroid (CS) in short-term pain reduction in patients with plantar fasciopathy (PF); (2) Compare the efficacy of WB, PRP, and CS in long-term pain reduction in patients with PF; (3) Identify the potential complication of corticosteroid injection for plantar fasciopathy; and (4) Identify the components of whole blood that might influence the growth factors in healing process. LEVEL: Advanced ACCREDITATION: The Association of Academic Physiatrists is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.The Association of Academic Physiatrists designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

Effectiveness of Laser Acupuncture in Alleviating Chronic Insomnia: A Single-Blinded Randomized Controlled Trial.

STUDY OBJECTIVES: This study investigates the therapeutic effect of Low Level Laser Therapy (LLLT) acupuncture for chronic insomnia. METHODS: Thirty-seven adult subjects with chronic insomnia were recruited and randomly assigned to three groups, namely, Group A (6 pairs of acupoints: Ex-HN 22, HT 7, SP 6, KI 3, LR 3, and PC 6, bilaterally distributed); Group B (acupoints as for Group A other than PC 6, which was applied only on the left side [i.e., the dominant side of the PC meridian] and the addition of DU 20, which is the main tonic acupoint for integration of all the meridians); and a control group (sham LLLT). The subjects in the treatment groups (i.e., Groups A and B) received LLLT acupuncture and those in the control group received sham LLLT for 15 minutes per session twice a week for five weeks. The sleep quality of all the subjects was evaluated using the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Hospital Anxiety and Depression Scale (HADS), and a sleep diary. In addition, the sympathetic activity before and after every treatment sessions was measured using the Heart Rate Variability (HRV). RESULTS: All three groups showed an improved PSQI score. However, only Group A showed a significant reduction in the sleep onset latency and number of awakenings at night and a higher sleep efficiency and ESS score. Furthermore, Group B showed an increased low frequency power and normalized low frequency of the HRV signal and a lower normalized high frequency power, suggesting an increased sympathetic activity and decreased parasympathetic activity. CONCLUSIONS: For chronic insomnia insomniacs, LLLT appears to shorten the sleep latency, decrease the number of awakening events at night, and improve the sleep efficiency.

Complete mitochondrial DNA genome of Microphysogobio brevirostris (Cypriniformes: Cyprinidae).

In this study, we sequenced the complete mitochondrial genome of Microphysogobio brevirostris (Cypriniformes, Cyprinidae), an endemic primary freshwater fish in Taiwan. This mitochondrial genome, consisting of 16,608 base pairs (bp), encoded 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a non-coding control region as those found in other vertebrates, with the gene synteny identical to that of typical vertebrates. Control region (D-Loop), of 929 bp lengths long, is located between tRNA(Pro) and tRNA(Phe). The overall base composition of the heavy strand shows T 26.28%, C 26.62%, A 30.26%, and G 16.85%, with a slight AT bias of 56.53%.

Measurement properties of streamlined wolf motor function test in patients at subacute to chronic stages after stroke.

UNLABELLED: BACKGROUND. Previous research using the streamlined Wolf Motor Function Test (SWMFT) has focused either on the 3- to 9-month period or on the >12-month period after stroke and lacked the information for those at 9 to 12 months. Whether SWMFT scores reflect motor deficit and recovery from early to late stages after stroke remains unclear. OBJECTIVE: A retrospective study using the Functional Ability Scale (FAS) was conducted to evaluate whether all SWMFTs items measure the poststroke recovery of upper extremity (UE) motor function and if they could be used for patients within 9 to 12 months after a stroke. METHODS: Rasch analysis was conducted, and data were drawn from patients 3 months to years after a stroke. RESULTS: The continuum of UE motor function in SWMFT-FAS was supported. Subacute patients had the best motor function, followed by the 9- to 12-month group, and then chronic patients. Variation in UE motor function was large (2.35-2.72 logits), and motor abilities of these 3 groups overlapped. The 8 SWMFT items could target a broad range of UE motor function, from -8.28 to 7.80 logits. The average difficulty of these 8 items also matched the UE motor ability of the subgroup at 9 to 12 months after stroke, and individual versions of the SWMFT performed well to assess the motor ability of this group. CONCLUSIONS: The SWMFTs had sound hierarchical properties. The SWMFT-Chronic or the SWMFT-Subacute could be used to evaluate UE function of this subgroup at 9 to 12 months after stroke.

Global motion percept mediated through integration of barber poles presented in bilateral visual hemifields.

How is motion information that has been obtained through multiple viewing apertures integrated to form a global motion percept? We investigated the mechanisms of motion integration across apertures in two hemifields by presenting gratings through two rectangles (that form the dual barber poles) and recording the perceived direction of motion by human observers. To this end, we presented dual barber poles in conditions with various inter-component distances between the apertures and evaluated the degree to which the hemifield information was integrated by measuring the magnitude of the perceived barber pole illusion. Surprisingly, when the inter-component distance between the two apertures was short, the perceived direction of motion of the dual barber poles was similar to that of a single barber pole formed by the concatenation of the two component barber poles, indicating motion integration is achieved through a simple concatenation mechanism. We then presented dual barber poles in which the motion and contour properties of the two component barber poles differed to characterize the constraints underlying cross-hemifield integration. We found that integration is achieved only when phase, speed, wavelength, temporal frequency, and duty cycle are identical in the two barber poles, but can remain robust when the contrast of the two component barber poles differs substantially. We concluded that a motion stimulus presented in bilateral hemifields tends to be integrated to yield a global percept with a substantial tolerance for spatial distance and contrast difference.

Sonographic features of soft tissue tumors in the hand and forearm.

BACKGROUND: High-resolution sonography is well suited for screening soft tissue masses because of its safety, low cost, and real-time, dynamic imaging. The purpose of our study was to elaborate the preoperative sonographic features of soft tissue tumors of the hand and forearm and the corresponding histologic results. METHODS: Thirty-one soft tissue tumors of the hand and forearm were evaluated by ultrasound preoperatively. The mobility, consistency, echogenicity, margin, and color Doppler signal of each tumor were assessed. Dynamic study was also performed. The pathologic diagnosis was obtained after subsequent surgery. RESULTS: The pathologic diagnoses of these soft tissue lesions were lipoma (n = 6), ganglion cyst (n = 6), neurilemmoma (n = 3), neurofibroma (n = 3), giant cell tumor (n = 10), tenosynovitis (n = 2), and malignant lymphoma (n = 1). An adjacent tendon or communication duct extending to the joint space could be found in most giant cell tumors and ganglion cysts; a traceable nerve could be found in most nerve sheath tumors. All benign tumors appeared well-defined. The only malignant tumor appeared ill-defined without a color Doppler signal. CONCLUSION: Sonography enables a reliable diagnosis of the cystic or solid nature of soft-tissue lesions, accurate estimation of the volume, and precise three-dimensional localization of the abnormality. Examiners should perform a dynamic examination and trace the adjacent structure to obtain more diagnostic clues.