Nuclear Factor I/A Controls A-fiber Nociceptor Development / 神经科学通报·英文版

Noxious mechanical information is transmitted through molecularly distinct nociceptors, with pinprick-evoked sharp sensitivity via A-fiber nociceptors marked by developmental expression of the neuropeptide Y receptor 2 (Npy2r) and von Frey filament-evoked punctate pressure information via unmyelinated C fiber nociceptors marked by MrgprD. However, the molecular programs controlling their development are only beginning to be understood. Here we demonstrate that Npy2r-expressing sensory neurons are in fact divided into two groups, based on transient or persistent Npy2r expression. Npy2r-transient neurons are myelinated, likely including A-fiber nociceptors, whereas Npy2r-persistent ones belong to unmyelinated pruriceptors that co-express Nppb. We then showed that the transcription factors NFIA and Runx1 are necessary for the development of Npy2r-transient A-fiber nociceptors and MrgprD C-fiber nociceptors, respectively. Behaviorally, mice with conditional knockout of Nfia, but not Runx1 showed a marked attenuation of pinprick-evoked nocifensive responses. Our studies therefore identify a transcription factor controlling the development of myelinated nociceptors.

Comparison of Three Modalities for Assessing Block Levels during Spinal or Combined Spinal Epidural Anesthesia for a Cesarean Delivery / 대한마취과학회지

BACKGROUND: Assessing block levels during regional anesthesia has been mainly performed by three sensory modalities: cold, sharp pinprick (analgesia), and pinprick touch (anesthesia). Though sharp pinprick is more commonly used, pinprick touch has been emphasized to be more accurate and predictive by some. We compared block levels and discriminating power between the three modalities in spinal anesthesia (SA) and combined spinal epidural anesthesia (CSEA). METHODS: Forty-six cesarean parturients were randomly given SA (n = 23) or CSEA (n = 23). SA was performed with intrathecal hyperbaric bupivacaine 0.5%-9 mg and fentanyl 20 microgram, and CSEA with intrathecal hyperbaric bupivacaine 0.5%-6 mg and fentanyl 20mug followed by epidural bupivacaine 0.25%-10 ml 5 min later. Upper block levels were measured with cold (alcohol swab), sharp pinprick (25G Whitacre) and pinprick touch (25G Whitacre) at 5, 10, 15, 20, 30, 60, 90, and 120 min after intrathecal injections. RESULTS: There were no complaints of pain through the operation by any patient. The maximum levels (median) using cold, sharp pinprick, or pinprick touch were T1, T2, and T4 in SA and T1, T3, and T4 in the CSEA group and there was no differences between groups. At every measuring time, there were significant differences in block heights of the three modalities in the upper mentioned order. In 5 patients (3 in SA, 2 in CSEA), there was a reverse order between the levels of cold sensation and analgesia. Pinprick touch was kept at the lowest levels at all times, and could discriminate the two blocks at two onset times (5, 10 min), sharp pinprick at one time (5 min) but cold sensation could not. CONCLUSIONS: There were marked differences in block heights measured by the three modalities in the decreasing order of cold, sharp pinprick, and pinprick touch. At the onset of the blocks, pinprick touch was the most discriminating to differentiate the two blocks, followed by a sharp pinprick.

Effect of Loss of Epidural Negative Pressure on Spinal Sensory Blokade Level of Spinal Anesthesia / 대한마취과학회지

BACKGROUND: We postulated that loss of epidural negative pressure might affect on the sensory blockade level of spinal anesthesia. METHODS: Thirty nine patients were involved in our study; group 1, spinal anesthsia with 23G spinal needle (n=20): group 2, spinal anesthesia with 27G spinal needle through the 18G Weiss epidural needle (n=19). Sensory blockade level was checked by pinprick test at 5, 10, 15, 20, 25, 30, 40, 60 and 90 minutes after spinal anesthesia. RESULTS: There was no difference of sensory blockade level between group 1 and 2. CONCLUSION: From above result, there was no evidence of loss of epidural negative pressure affecting on the spinal sensory blockade level.

Comparison of Weighted Needle Pinprick Sensory Thresholds and Sensory Nerve Conduction Studies in Diabetic Patients / 예방의학회지

This study was conducted to determine the correlation between weighted needle pinprick sensory threshold(PPT) and sensory nerve conduction tests. The subjects were 53 healthy controls, 31 diabetic patients without peripheral neuropathic symptoms(DM) and 36 diabetic patients with peripheral neuropathic symptoms(DN). PPT was measured on the index and little fingers, bilaterally, as well as under the lateral malleolus, bilaterally. In electrophysiologic assessment the left and right median, ulnar and sural nerves were studied. Each mean PPTs was high in order of controls, DM and DN. Age adjusted PPT was significantly different among three groups on right little finger(p<0.05) and left malleolus(p<(0.05), but not significantly different between DN and DM on other sites. Each sensory nerve conduction velocity and amplitude was statistically significantly different among three groups(p<0.05). Correlations of PPT with sensory nerve conduction velocity and amplitude were statistically significant on each site and ranged from -0.4203(left malleolus) to -0.5649(right index finger) and from -0.3897(left index finger) to -0.6200(right index finger), respectively. When electrophysiological study is not feasible, measurement of PPT may be helpful for the assessment of peripheral sensory neurological function.

Weighted Needle Pinprick Sensory Threshold (WPT) and Arthropornetric Parameters / 대한산업의학회지

To assess the relationship of pinprick sensory threshold with height and weight, Ninety seven healthy young (age 19 to 28) males were tested on their anatomical snuff box of both Hands. Their WPT was measured by device holding and moving weighted needle sensory threshold apparatus. Mean of the WPT was 0.43(+/-0.24) g in left and, 0.53( 0.30) g in right hand. Difference of WPT between the right and left hand appeared statistically significant (p<0.01) . Correlation coefficient of WPT with height was 0.26461 (p<0.01) in left and, 0.31856 (p<0.01) in right hand. Weight was statistically significantly correlated with WPT in left hand (r=0.24932, p<0.01) The study shows that the left-right difference and influence of height in pinprick sense may exist in normal healthy male adults.

Design of noninvasive anesthesia level determinator / 医疗卫生装备

0.05). Conclusion Noninvasive anesthesia level determinator has similar quality compared to pinprick method in measuring the levels of block. Moreover, noninvasive anesthesia level determinator is safer and its energy of stimulation can be controlled easily.