Research progress of health lighting and prevention and control of children's myopia / 眼科新进展

The prevalence of myopia is substantial in China,significantly impacting children's visual health.Current research indicates that extended screen time and inadequate outdoor activities are pivotal factors contributing to childhood myopia.These risk factors are closely associated with light parameters,including intensity,duration,frequency and spec-trum.Moreover,inappropriate nighttime lighting can disturb children's circadian rhythms and sleep and contribute to myo-pia development.This study reviews clinical research and epidemiological data on screen time,outdoor activities,light properties and circadian rhythms,aiming to offer recommendations and guidance for preventing myopia in children.

Metabonomics Analysis of Brain Stem Tissue in Rats with Primary Brain Stem Injury Caused Death / 法医学杂志

OBJECTIVES@#To explore the potential biomarkers for the diagnosis of primary brain stem injury (PBSI) by using metabonomics method to observe the changes of metabolites in rats with PBSI caused death.@*METHODS@#PBSI, non-brain stem brain injury and decapitation rat models were established, and metabolic maps of brain stem were obtained by LC-MS metabonomics method and annotated to the HMDB database. Partial least square-discriminant analysis (PLS-DA) and random forest methods were used to screen potential biomarkers associated with PBSI diagnosis.@*RESULTS@#Eighty-six potential metabolic markers associated with PBSI were screened by PLS-DA. They were modeled and predicted by random forest algorithm with an accuracy rate of 83.3%. The 818 metabolic markers annotated to HMDB database were used for random forest modeling and prediction, and the accuracy rate was 88.9%. According to the importance in the identification of cause of death, the most important metabolic markers that were significantly up-regulated in PBSI group were HMDB0038126 (genipinic acid, GA), HMDB0013272 (N-lauroylglycine), HMDB0005199 [(R)-salsolinol] and HMDB0013645 (N,N-dimethylsphingosine).@*CONCLUSIONS@#GA, N-lauroylglycine, (R)-salsolinol and N,N-dimethylsphingosine are expected to be important metabolite indicators in the diagnosis of PBSI caused death, thus providing clues for forensic medicine practice.

Analysis on occupational noise deafness in a provincial occupational disease diagnosis institution from 2016 to 2020 / 中国职业医学

@#Objective - （ ） To analyze the epidemiological characteristics of occupational noise induced deafness ONID （ ） diagnosed by Guangdong Province Hospital of Occupational Disease Prevention and Control GDHOD from 2016 to 2020 and - Methods the reasons non ONID diagnosis. The data of ONID patients diagnosed in GDHOD from 2016 to 2020 were collected “ from the Occupational Disease Report Card in the Occupational Disease and Occupational Health Information Monitoring ” “ ” - System subsystem of the China Disease Prevention and Control Information System . The data of non ONID subjects were ， collected from the occupational disease diagnosis archives in the same hospital and the relevant data were analyzed Results ， ， （ ） retrospectively. Of the 1 432 subjects 824 subjects were diagnosed as ONID patients mainly of mild ONID 86.0% . （M） ， M Male patients accounted for 88.0%. The median of diagnosis age was 45.0 years old and of length of employment of ， ， ， diagnosis was 8.3 years. ONID patients were mainly found in Zhongshan Dongguan Zhuhai Jiangmen and Guangzhou City in ， ， （ ） the Pearl River Delta accounting for 67.6%. The cases distributed in 519 enterprises mainly on manufacturing 90.2% . ， - ， ； Among the 139 enterprises each enterprise had 2 11 patients worked within five years accounting for 53.9% 91.1% of the -， - - - ONID patients were distributed in large medium and small enterprises. ONID patients mainly worked in non public enterprises that accounted for 91.3%. There were 606 subjects could not be diagnosed as ONID. The main reasons for not being （ ）， diagnosed were that the weighted value of better ear hearing threshold was less than 26 dB 34.8% the working history of （ ）， occupational noise exposure was less than three years 31.5% the weighted value of better ear hearing threshold was less thanConclusion 26 dB and the average hearing threshold of binaural high frequency was less than 40 dB 16.2% . The ONID ， ， -， - patients have the characteristics of group aggregation. The Pearl River Delta manufacturing industry large medium and - - ： small non public enterprises are the key points of ONID prevention. The main reasons for not being diagnosed as ONID were ， the working history of occupational noise exposure was less than three years the weighted value of better ear hearing threshold ， - was less than 26 dB and the average high frequency hearing threshold of both ears was less than 40 dB.

Preparation of Rehmanniae Radix Juice for Baihe Dihuangtang Based on UPLC-Q-TOF-MS / 中国实验方剂学杂志

ObjectiveTo compare the four preparation methods of Rehmanniae Radix juice described in ancient literature and find the method that is most suitable for the preparation of Rehmanniae Radix juice used in Baihe Dihuangtang. MethodThe ancient medical books record four methods for preparing Rehmanniae Radix juice： crushing fresh Rehmanniae Radix for juice， steaming fresh Rehmanniae Radix for juice， boiling fresh Rehmanniae Radix for juice， and boiling dry Rehmanniae Radix for juice. Ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry （UPLC-Q-TOF-MS） was employed to detect the compounds in the four juice samples， followed by principal component analysis （PCA）. Result① Totally 27 compounds were identified in the juice samples， including 10 iridoid glycosides， 14 phenylethanoid glycosides， 2 phenolic acids， and 1 irisone. Among them， 15 common compounds were shared by the four juice samples， including 7 iridoid glycosides， 7 phenylethanoid glycosides， and 1 phenolic acid. ② Five common compounds in the four juice samples can be matched with the reference standards， which were catalpol， aucubin， rehmannioside D， ajugol， and purpureaside C. ③ Verbascoside and isoacteoside were not detected in the juice prepared by crushing fresh Rehmanniae Radix， while it was detected in the other three juice samples， which indicated that the two components were produced after heating rather than being the original components in fresh Rehmanniae Radix. ④ The comparison of the ion fragments demonstrated that verbascoside was produced from purpureaside C after the cleavage of the glycosidic bond and removal of a molecule of mannose. ⑤ Isoacteoside could be isomerized from verbascoside， and its relative content increased with the extension of heating time. However， the relative content of verbascoside and purpureaside C did not decrease significantly. Therefore， it was hypothesized that purpureaside C was produced from its upstream component. ConclusionThe juice prepared by crushing fresh Rehmanniae Radix has the chemical composition significantly different from the juice samples prepared with the other 3 methods， while the latter 3 juice samples had similar chemical composition. Although all the four methods can be used， it is more suitable to prepare Rehmanniae Radix juice by steaming fresh Rehmanniae Radix， boiling fresh Rehmanniae Radix， and boiling dry Rehmanniae Radix.

Occupational exposure limit of trimethyltin chloride in workplace air / 中国职业医学

OBJECTIVE: To establish the occupational exposure limit for trimethyltin chloride(TMT) in workplace air. METHODS:According to the GBZ/T 210.1-2008 Guide for Establishing Occupational Health Standards--Part 1: Occupational Exposure Limits for Airborne Chemicals in the Workplace, the relevant literatures on toxicology, population epidemiology and foreign occupational exposure limit of TMT were collected and analyzed. A total of 276 workers with TMT occupational exposure were selected as the exposure group and 25 workers without TMT occupational exposure were selected as the control group.Worksite survey of occupational health and occupational medical examination were carried out. Combined with the literature data, the occupational exposure limit of TMT in the workplace air was calculated by using the 90% medical reference level(internal exposure limit) of the urine TMT level of workers who exposed to TMT without moderate hypokalemia. RESULTS: The time-weighted average of TMT in the workplace air is 0.100 mg/m~3 and the short-term exposure limit is 0.200 mg/m~3 in the United States based on total organic tin. The highest concentration of TMT in the workplace air in Germany is 0.005 mg/m~3. The literature data analysis results showed that the incubation period of TMT poisoning is mostly 3-6 days, and the main symptoms of TMT poisoning are hypokalemia in the early stage, followed by neuropsychiatric symptoms such as headache, memory loss and aggressive behavior. The median(M) and the 0-100 th percentile(P_0-P_(100)) of exposure to TMT were 8.35(< 0.20-91.40) μg/m~3 in the exposure group. The individual TMT exposure level of workers in different positions from high to low were crushing, granulation, withdrawal and assembly positions. The M(P_0-P_(100)) of urinary TMT level in the exposure group was 16.94(<0.50-591.14) μg/L. There was a positive correlation between the individual TMT exposure level and urine TMT level in the exposure group(Spearman correlation coefficient=0.62, P<0.01). The detection rate of hypokalemia in the exposure group was higher than that in the control group(26.1% vs 4.0%, P < 0.05). However, there was no significant difference in the detection rate of moderate hypokalemia between the two groups(3.3% vs 0.0%, P>0.05). The 90% medical reference value of urine TMT was 89.90 μg/L in workers exposed to TMT without moderate hypokalemia. CONCLUSION: In order to prevent acute hypokalemia damage caused by TMT, we recommended that the occupational exposure limit of TMT in the workplace air should be set at 0.025 mg/m~3 in China, and this limit should be the maximum allowable concentration.

Report Quality of Clinical Practice Guidelines of Rehabilitation Based on RIGHT / 中国康复理论与实践

@#Objective To evaluate the quality of reporting of clinical practice guidelines of rehabilitation.Methods A comprehensive retrieve was performed in electronic databases of PubMed, EMBASE, CNKI, China Biology Medicine disc, Wanfang data, etc., from January 1, 2017 to January 11, 2020. Supplementary searches had been done on relevant websites. Two researchers reviewed literatures and assessed the reporting quality independently by using Reporting Items for Practice Guidelines in Healthcare (RIGHT), and any disagreements needed to be discussed in a consensus meeting.Results A total of 16 guidelines were included, with an average reporting rate of (44.8±27.9)%. Among the seven domains of RIGHT, basic information was reported the highest (57.3%), and evidence (31.3%) and other information (31.3%) was the lowest. The reporting rate was less as the guidelines published in China than in foreign contries (OR = 0.80, 95%CI 0.56-1.16), in original version than in update version (OR = 0.79, 95%CI 0.54-1.16); and higher as developed by various societies or associations than developed by non-societies or associations (OR = 1.15, 95%CI 0.82-1.61), however, no statistically significant difference was found in above comparisons.Conclusion Current clinical practice guidelines of rehabilitation reported with low quality. It is proposed that future guideline developers should report guidelines after RIGHT statements, including key information and content, in order to improve the quality of reporting guidelines.

NF-κB Inhibitor Parthenolide Promotes Renal Tubules Albumin Uptake in Type 2 Diabetic Nephropathy / 中国医学科学杂志(英文版)

Objective Injured tubular reabsorption is highlighted as one of the causes of increased albuminuria in the early stage of diabetic nephropathy; however, the underlying mechanism has not been fully elucidated. In this study, we aimed to explore whether reducing inflammation and remodeling the insulin signaling pathway could improve albumin uptake of renal tubules. Methods 8-week-old male db/db mice (n=8), a type 2 diabetic nephropathy model, administered with nuclear factor kappa-B (NF-κB) inhibitor parthenolide (PTN, 1 mg/kg) intraperitoneally every other day for 8 weeks, were as the treatment group. Meanwhile, the age-matched male db/m mice (n=5) and db/db mice (n=8) were treated with saline as the control group and type 2 diabetic nephropathy group. When the mice were sacrificed, blood and urine were collected to examine homeostasis model assessment of insulin resistance (HOMA-IR) and urine albumin creatinine ratio, and kidney samples were used to analyze histopathologic changes with periodic acid-Schiff (PAS) staining, NF-κB p65, phosphorylation of AKT (p-AKT), amnionless and cubilin expressions with immunohistochemistry as well as western blot, and the albumin uptake of renal tubules by using immunofluorescence. In addition, HKC cells were divided into the insulin group treated with insulin alone, the TNF-α group treated with insulin and tumor necrosis factor (TNF-α), and the TNF-α+PTN group exposed to PTN, insulin and TNF-α. The levels of albumin uptake and expression levels of NF-κB p65, p-IRS-1/IRS-1, p-AKT/AKT, amnionless and cubilin in HKC cells were measured. Results Compared with the db/db group, the db/db+PTN group demonstrated decreased levels of HOMA-IR (36.83±14.09 vs. 31.07±28.05) and urine albumin creatinine ratio (190.3±7.3 vs. 143.0±97.6 mg/mmol); however, the differences were not statistically significant (P>0.05). Periodic acid-Schiff staining showed PTN could alleviate the glomerular hypertrophy and reduce the matrix in mesangial areas of db/db mice. The renal expression of NF-κB p65 was increased and p-AKT (s473) decreased in the db/db group compared with the db/m group (P<0.05). PTN significantly reduced the renal expression of NF-κB p65 and ameliorated the decline of p-AKT (s473) compared with the db/db group (P<0.05). Compared with the db/m group, the expression of amnionless and cubilin decreased and albumin uptake in tubules were reduced in the db/db group (P<0.05), and PTN could significantly increase the expression of cubilin (P<0.05), and improve albumin uptake in tubules. Insulin promoted albumin uptake and the expression of amnionless and cubilin in HKC cells (P<0.05). TNF-α stimulated the expression of NF-κB p65, increased p-IRS-1 (s307) and reduced p-AKT (s473) in HKC cells (P<0.05). In the TNF-α+PTN group, the expression of NF-κB p65 declined and p-IRS-1 (s307) and p-AKT (s473) were restored, compared with the TNF-α group (P<0.05). The expression of amnionless and cubilin decreased in the TNF-α group (P<0.05), and PTN could significantly increase the expression of cubilin (P<0.05). Conclusions Inflammation caused damage to insulin signaling, which reduced amnionless-cubilin expression and albumin uptake. PTN could reduce inflammation and remodel the impaired insulin signaling pathway, which promoted the expression of cubilin and albumin uptake. Our study can shed light on the role of inflammation in the reduction of albumin uptake of renal tubules in type 2 diabetic nephropathy.

Expression of Lysosomal Membrane Proteins LAMP1, TPC1 and TPC2 in Acute Myeloid Leukemia Cells and Its Clinical Significance / 中国实验血液学杂志

OBJECTIVE@#To investigate the relationship between the expression of lysosomal membrane proteins LAMP1, TPC1 and TPC2 in acute myeloid leukemia (AML) cells and clinical indications of AML and to explore the possible role in the genesis and development of AML and clinical significance.@*METHODS@#Real-time quantitative PCR was used to detect the mRNA expression of LAMP1, TPC1 and TPC2 in AML cell lines (HL-60, NB4) and 57 patients with acute myeloid leukemia (including 44 initially treated patients and 13 relapsed and refractory patients). The relationship of mRNA expression levels with clinical indicators and post-chemotherapy remission was analyzed.@*RESULTS@#Compared with CD34 hematopoietic stem cells (HSC), the expression levels of LAMP1 and TPC1 in AML cell lines HL-60 and NB4 significantly increased, while the expression level of TPC2 was not significantly different. The expression levels of LAMP1, TPC1 and TPC2 in bone marrow mononuclear cells (BMMNC) of AML patients were higher than those in normal human BMMNC (P90%) were also high. There was no significant difference in the expression of LAMP1, TPC1 and TPC2 between CD34HSC of patients with AML and relapsed/refractory patients (P>0.05). No correlation was found between age, sex and genotype and expression of membrane proteins (P>0.05). The expression levels of LAMP1 and TPC1 positively correlated with the number of white blood cells in peripheral blood of patients (P<0.01). LAMP1 and TPC2 were found to be associated with remission after a course of chemotherapy in newly diagnosed patients. Initially treated patients with high expression of LAMP1 in the bone marrow not easily relieved after one course of chemotherapy. Patients with high expression of TPC2 in the bone marrow more likely to be relieved after one course of chemotherapy.@*CONCLUSION@#The mRNA of the three membrane proteins are highly expressed in AML patients, and LAMP1 and TPC1 are risk factors for AML disease progression. High expression of TPC2 is beneficial for chemotherapy of patients with newly diagnosed AML.

Protective effect of notoginsenoside R1 on neuron injury induced by OGD/R through ATF6/Akt signaling pathway / 中国中药杂志

Notoginsenoside R1(NGR1),a critical compound in traditional herb Panax notoginseng, is a kind of estrogen receptor agonist.It is reported to exhibit anti-apoptotic,anti-oxidative and anti-inflammatory properties activity, so it is widely used for treatment of various diseases.In order to investigate the potential neuroprotective effect of NGR1 in hypoxic-ischemic brain damage(HIBD), primary cortical neurons were used in this study to establish oxygen-glucose deprivation/reoxygenation(OGD/R) injury models. They were treated with NGR1 and estrogen receptor inhibitor ICI-182780 respectively, then the neuronal survival, cell membrane integrity and apoptosis were assessed by MTT assay,lactate dehydrogenase test(LDH) and Hoechst 33342 stain respectively, while the protein expression levels of ATF6α,p-Akt,Akt,Bax and Cleaved Caspase-3 were measured by Western blotting. Results indicated that as compared with the blank control group,OGD/R could induce cell injury and apoptosis(P<0.05), reduce relative integrity of cell membrane(P<0.05), decrease protein expression of ATF6α,p-Akt(P<0.05), and increase protein expression of Bax and Cleaved Caspase-3(P<0.05) in the primary cortical cells. After NGR1 treatment, the expression levels of ATF6α,p-Akt were obviously increased, and the expression levels of Bax and Cleaved Caspase-3 and the apoptosis of neuron were decreased(P<0.05). However, these neuroprotective properties of NGR1 against ODG/R-induced cell damage could be blocked by ICI-182780. This finding indicated that NGR1 may protect the primary cortical neurons against OGD/R induced injury,and the mechanism may be associated with accelerating the activation of the ATF6/Akt signaling pathway via estrogen receptors.

Clinical analysis on four cases of occupational chronic toxic peripheral neuropathy caused by 1-bromopropane / 中国职业医学

OBJECTIVE: To analyze the clinical features of occupational chronic toxic peripheral neuropathy caused by1-bromopropan( 1-BP). METHODS: Clinical data of 4 patients who suffered from occupational chronic toxic peripheral neuropathy caused by 1-BP were collected for retrospective analysis. RESULTS: The 4 male patients were ultrasonic cleaning operation workers in a hardware vacuum coating enterprise. They were exposed to high levels of 1-BP for 9-11 months. The main clinical manifestations were varying degrees of sensory disorder and dyskinesia. The main symptoms were progressive increase of numbness and fatigue in the lower extremities. These symptoms might be accompanied by unsteady gait.Physical examination showed muscle strength weakness in the double lower limbs. The hypalgesia,pselaphesia,topesthesia and pallesthesia decreased in the double lower limbs or 4 limbs. The bilateral achilles tendon reflex mainly showed reduced or disappeared. One case had sensory ataxia. Electroneuromyography examination showed different levels of peripheral nerve damage among the cases. The motor nerve conduction velocity and sensory nerve conduction velocity reduced commonly. The axon and myelin sheath damage were visible. On the basis of GBZ / T 247-2013 Diagnosis of Occupational Chronic Toxic Peripheral Neuropathy Caused by Chemicals,these cases were diagnosed as occupational chronic toxic peripheral neuropathy caused by 1-BP. CONCLUSION: Long-term exposure to high level 1-BP can lead to chronic poisoning with peripheral nervous system damage. The diagnosis can be made based on the 1-BP exposure history,clinical features and the neurogenic damage found in electroneuromyography examination.

Influence factors of hearing loss in pre-job workers exposed to noise in metal manufacturing industries / 中国职业医学

OBJECTIVE: To examine the hearing status of pre-job workers exposed to noise in metal manufacturing industries,and to analyze the related influencing factors. METHODS: A judgement sampling method was adopted to choose1 597 pre-job workers exposed to noise in metal manufacturing industries as the study subjects. The data of workers' occupational health examination was collected,and the influencing factors of hearing loss were analyzed. RESULTS: Among the 1 597 individuals,631( 39. 5%) cases reported occupational noise exposure history( noise exposure group) with the length of service of 0. 20( 0. 10-0. 30) years; 966( 60. 5%) cases denied occupational noise exposure history( no-noise exposure group). The hearing loss detection rate was 46. 1%( 737 /1 597); among them,the occupational contraindication detection rate was 13. 9%( 222 /1 597),and the detection rate of other kinds of hearing loss was 32. 2%( 515 /1 597).The detection rates in workers with occupational contraindication and the other kinds of hearing loss in noise exposure group were higher than those in the non-noise exposure group( 16. 5% vs 12. 2%,50. 6% vs 43. 3%,P < 0. 05). The male workers had higher incidence than female workers [the odds ratio( OR) were 1. 958 and 2. 331,respectively,P < 0. 01);the workers with age > 25 years had higher incidence than those with age ≤ 25 years( OR were 2. 390 and 2. 245,respectively,P < 0. 01); the noise exposure workers had higher incidence than non-noise exposure ones( OR were 1. 536 and 1. 287,respectively,P < 0. 05). CONCLUSION: Pre-job occupational health examination is helpful for early detection of occupational contraindication in noise exposure workers. Attention should be paid to the male workers,the older workers,and those with occupational noise exposure history when conducting occupational health examination.

Establishing a clinical pathway for occupational chronic mild lead poisoning / 中国职业医学

OBJECTIVE: To establish an effective clinical pathway of hospitalization process for occupational chronic mild lead poisoning within the framework of project time; to formulate a rational and effective management model for the diagnosis and treatment. METHODS: Occupational chronic mild lead poisoning was selected as a disease for pilot study based on GBZ 37-2015 Diagnosis of Occupational Chronic Lead Poisoning. According to evidence-based medicine criteria,the clinical procedure was developed,preliminary used and evaluated in clinical practice in several hospitals,with the best treatment scheme of the disease. The principal methods used are literature research,case analysis and expert consultation.RESULTS: Standardized documents relevant to clinical pathway for occupational chronic mild lead poisoning have been formulated,including standardized in-hospital treatment process,Clinical Pathway Forms for medical staff and Consent Documents of Clinical Pathway for Patients. Preliminary clinical research showed that this clinical pathway is conducive to standardizing medical process,improving medical quality,shortening the time in hospital,reducing medical cost and the waste on medical resources. CONCLUSION: The results confirm that the clinical pathway for occupational chronic mild lead poisoning is scientific,rational,normative and practical. It will surely contribute to promote the management of disease diagnosis and treatment.

CKS2 affects filopodia formation of A2780 cells through regulating CDC42 alternative splicing / 解放军医学杂志

Objective To study the effect of CKS2 on filopodia formation of A2780 cells through regulating CDC42 alternative splicing. Methods The filopodia were observed after CKS2 of A2780 cells were knocked down by lentivirus-mediated shRNA; the migrating ability of A2780 cells was also measured by wound healing assay; the expression levels of splicing variants CDC42-V1 and CDC42-V2 mRNA was determined by real time PCR after CKS2 knockdown. The expression levels of CKS2, CDC42-V1 and CDC42-V2 mRNA were further measured in each ovarian cancer and normal ovarian samples in the same way. Results The filopodia on A2780 cells obviously decreased, and the migrating ability of A2780 cells was also remarkably reduced after CKS2 knockdown (P<0.05). Meanwhile the expression of CDC42-V1 mRNA decreased and CDC42-V2 mRNA increased after CKS2 knockdown (P<0.05). Real time PCR results showed that the mRNA expression levels of CKS2 and CDC42-V1 were higher in ovarian cancer samples than in normal ovarian tissues; however, the expression level of CDC42-V2 mRNA was lower in ovarian cancer samples than in normal ovarian tissues (P<0.05). ConclusionCKS2 may affect the filopodia formation of A2780 cells through regulating CDC42 alternative splicing, and further affect the migrating ability of A2780 cells.

Effect of angiotensin II on potassium channels of ischemic ventricular myocytes of the guinea pig / 生理学报

The experiments were carried out on guinea pig isolated ventricular myocytes by using whole-cell patch clamp. The effects of angiotensin II (Ang II) on potassium ion channels of acute ischemic myocytes were observed. Whole-cell patch clamp recordings showed that physiological potassium current, including delayed rectifier potassium current and inward rectifier potassium current were inhibited under the condition of simulated ischemia, and then further inhibited by treatment with Ang II. ATP-sensitive potassium currents were increased under simulated ischemia and were further enhanced by Ang II treatment.

Effect of angiotensin II on L-type calcium channel in ischemic ventricular myocytes of the guinea pig / 生理学报

Using whole cell patch clamp, the effects of angiotensin II (Ang II) on the current L-type calcium channel (I(Ca.L)) were observed in guinea pig isolated ventricular myocytes under simulated ischemia condition, which was realized through hypoxia, glucose deficiency, high lactic acid and acidosis. The results showed that, under the condition of simulated ischemia, the peak of I(Ca.L) was reduced with maximal activation potential at 0 mV. Administration of Ang II (100 nmol/L) enhanced the peak of I(Ca.L) during ischemia and shifted the maximal activation potential to -10 mV. The possible mechanism of these effects is discussed.