Objective To evaluate the accuracy of continuous noninvasive hemoglobin ( Hb ) monitoring in the patients undergoing cesarean section. Methods A total of 200 patients, at 36-42 weeks of gestation, aged 19-40 yr, with body mass index of 20.5-35.1 kg∕m2 , of ASA physical statusⅠorⅡ, undergoing elective cesarean section from June 2014 to October 2014 in our hospital, were enrolled. A sensor was positioned at patient′s finger and connected to the Masimo Radical?7 Pulse CO?Oximeter, a continuous noninvasive Hb measurement device. Noninvasive Hb obtained with Pulse CO?oximeter ( SpHb) was recorded. Before skin incision ( T0 ) , after delivery of the placenta ( T1 ) , after suturing the uterus ( T2 ) and at the end of operation ( T3 ) , blood samples from the radical artery were collected for determination of total Hb ( tHb) , and SpHb was also recorded. The agreement between two methods was assessed using Bland?Altman analysis. Results At T0-T3, tHb was 111±9, 103±8, 94±8 and (89±7) g∕L, respectively, and SpHb was 124 ± 9, 120 ± 12, 108 ± 9 and ( 103 ± 8 ) g∕L, respectively. Bland?Altman analysis showed that at T0-T3 , the mean difference between SpHb and tHb was 13.5, 17.1, 14.1 and 13.9 g∕L, respectively, and 95% confidence interval was 13.1-13.9, 16.5-17.7, 13.6-14.6 and 13.4-14.4 g∕L, respectively. The limit of agreement was 8.4-18.6, 9.1-25.1, 7.8-20.4 and 7.4-20.4 g∕L at T0-T3 , respectively, and the interchangeable limits of the two methods ranged between 3.5-23.5, 7.1-27.1, 4.1-24.1 and 3.9-23.9 g∕L at T0-T3 , respectively. The repeatability coefficient of tHb and SpHb was 16.5 and 15.8 g∕L, respectively. The relative error of SpHb was (4.6±1.0)%, (5.3±1.4)%, (4.9±1.2)% and (4.8±1.2)% at T0-T3, respectively. Conclusion Continuous noninvasive Hb monitoring provides good accuracy in the patients undergoing cesarean section.

Autapses selectively form in specific cell types in many brain regions. Previous studies have also found putative autapses in principal spiny projection neurons (SPNs) in the striatum. However, it remains unclear whether these neurons indeed form physiologically functional autapses. We applied whole-cell recording in striatal slices and identified autaptic cells by the occurrence of prolonged asynchronous release (AR) of neurotransmitters after bursts of high-frequency action potentials (APs). Surprisingly, we found no autaptic AR in SPNs, even in the presence of Sr²⁺. However, robust autaptic AR was recorded in parvalbumin (PV)-expressing neurons. The autaptic responses were mediated by GABA_A receptors and their strength was dependent on AP frequency and number. Further computer simulations suggest that autapses regulate spiking activity in PV cells by providing self-inhibition and thus shape network oscillations. Together, our results indicate that PV neurons, but not SPNs, form functional autapses, which may play important roles in striatal functions.
Parvalbumins/metabolism* ; Corpus Striatum/metabolism* ; Interneurons/physiology* ; Neurons/metabolism* ; Neostriatum