辅助生殖技术对儿童体格和孤独症行为的影响：一项3年纵向随访研究

背景 辅助生殖技术日益成熟,并广泛应用于临床。辅助生殖技术诞生的新生儿越来越多,这类儿童的健康问题也需要更多关注。目的 探讨辅助生殖技术对儿童体格和孤独症行为的影响,提高对辅助生殖儿童孤独症行为的关注度。方法 从病历信息系统中,按时间顺序选取2018年8月-2019年8月在安徽医科大学附属巢湖医院产科出生的辅助生殖新生儿（辅助生殖组）588例为研究对象。从病历信息系统中选取同一时间段该院产科自然受孕出生的600名新生儿为对照组。收集所有新生儿的性别、出生时母亲的年龄和受教育年限、出生孕周、出生体质量、出生身长以及3岁时体质量和身高数据,并在3岁随访时进行克氏孤独症行为量表（CABS）评定。结果 辅助生殖组母亲受教育年限长于对照组母亲受教育年限［（12.04±1.96）年vs.（11.34±2.90）年,t=-4.887,P<0.01］,出生孕周和出生体质量均低于对照组［（38.68±2.56）周vs.（39.53±2.91）周,t=5.315,P<0.01,（3 273.27±720.39）g vs.（3 158.29±701.74）g,t=2.792,P<0.05］。两组出生身长差异无统计学意义［（49.97±5.94）cm vs.（50.07±6.08）cm,t=-0.287,P>0.05］。3岁时,辅助生殖组体质量和身高均低于对照组［（16.16±2.53）kg vs.（16.96±1.67）kg,t=6.393,P<0.01,（95.81±4.50）cm vs.（97.47±7.49）cm,t=4.626,P<0.01］。对照组和辅助生殖组分别筛查出6例（1.00%）和15例（2.55%）存在孤独症行为,差异有统计学意义（χ²=4.113,P<0.05）。结论 辅助生殖技术可能对儿童体格和神经发育存在影响。     

成都市基层医院孤独症谱系障碍早期筛查技能培训效果的多中心研究

目的 了解孤独症谱系障碍（ASD）早期筛查技能培训对提高基层医院儿保科医护人员ASD早期筛查能力的效果。方法 于2021年9月，对成都市各县（市、区）共20家基层医院儿保科工作人员进行ASD早期筛查技能培训。以培训前后各基层医院向上级医院转诊的疑似ASD患儿人数、确诊ASD人数以及转诊的ASD患儿平均诊断年龄作为指标，评价培训效果。结果 培训后，基层医院转诊的疑似ASD患儿人数多于培训前，差异有统计学意义［（16.65±11.60）人vs.（3.40±2.23）人，t=5.431，P<0.01］。确诊ASD人数多于培训前，差异有统计学意义［（6.85±4.93）人vs.（2.45±1.67）人，t=4.171，P<0.01］。诊断年龄方面，培训后，ASD患儿平均诊断年龄小于培训前，差异有统计学意义［（34.95±11.67）个月vs.（42.2±14.64）个月，t=-2.553，P=0.019］。结论 对基层医院儿保科医护人员进行ASD早期筛查技能培训，可能有助于提高其ASD早期筛查能力。     

南宁市初三学生焦虑抑郁状况调查

目的 了解南宁市初三学生焦虑、抑郁水平及其与考试焦虑的关系,为对学生进行有针对性的心理干预提供参考。方法 于2021年5月-6月,采用简单随机抽样方法,在南宁市每个区/县内随机抽取一个初中学校,以每个学校初三年级中3个班级的学生为调查对象。采用考试焦虑量表（TAS）、焦虑自评量表（SAS）和抑郁自评量表（SDS）进行调查,采用Pearson相关分析考察各量表评分的相关性。结果 共2 080名学生参与此次调查,回收有效问卷1 826份（87.79%）。其中,999名（54.71%）初三学生感受到考试带来的不适感,检出存在焦虑和抑郁情绪者分别有577人（31.60%）、830人（45.45%）。女生TAS评分高于男生［（16.75±6.78）分vs.（15.08±6.97）分,t=-5.136,P<0.01］,女生SAS评分高于男生［（46.05±10.43）分vs.（44.16±10.87）分,t=-3.769,P<0.01］,女生SDS评分高于男生［（52.34±12.44）分vs.（49.98±12.17）分,t=-4.039,P<0.01］。相关分析显示,初三学生SAS、SDS评分与TAS评分均呈正相关（r=0.574、0.531,P均<0.01）,控制年龄和性别后,相关性仍存在（r=0.570、0.526,P均<0.01）。结论 南宁市初三学生的焦虑和抑郁症状检出率较高,且与考试焦虑均呈正相关。另外,女生的焦虑和抑郁水平均高于男生。     

有氧运动对男性慢性精神分裂症患者认知功能的影响

背景 精神分裂症的治疗方式以药物治疗及物理治疗为主,但均存在不良反应,影响治疗依从性及疗效。既往研究结果显示,有氧运动有助于改善阿尔茨海默病患者及抑郁障碍患者的认知功能。目前,国内对有氧运动改善精神分裂症患者认知功能的研究存在不足。目的 探讨有氧运动对男性慢性精神分裂症患者认知功能的影响,为精神分裂症患者的治疗提供参考。方法 选取2022年12月—2023年4月在芜湖市第四人民医院住院的76例男性慢性精神分裂症患者为研究对象,采用随机数字表法分为研究组（n=36）和对照组（n=40）。两组均接受常规药物治疗,研究组在此基础上接受为期8周、每周5次、每次60 min的有氧运动干预。于干预前后,采用MATRICS共识认知成套测验（MCCB）和Stroop色词测验（SCWT）分别评定患者的认知功能和执行功能。结果 干预后,研究组MCCB的连线测验用时短于对照组,空间广度测验及迷宫测验评分均高于对照组（Z=-2.070、-2.306、-2.375,P均<0.05）,重复测量方差分析结果显示,干预后,两组患者霍普金斯词语学习测验评分的时间主效应有统计学意义（F=39.067,P<0.05）,简易视觉空间记忆测验和言语流畅测验评分的时间与组别的交互效应均有统计学意义（F=10.092、9.252,P均<0.05）;干预后,研究组简易视觉空间记忆测验和言语流畅测验评分高于对照组（t=6.689、4.249,P均<0.05）,研究组简易视觉空间记忆测验和言语流畅测验评分均高于干预前（t=23.746、23.842,P均<0.05）。干预后,研究组SCWT色测验与词测验正确个数均多于对照组（Z=-2.358、-2.771,P均<0.05）,两组患者色测验、词测验和色词干扰测验反应时间的时间与组别的交互效应均有统计学意义（F=23.383、19.888、19.662,P均<0.05）,干预后,研究组色测验与色词干扰测验的反应时间均短于对照组（t=4.895、6.163,P均<0.05）,研究组色测验、词测验、色词干扰测验反应时间均短于干预前（t=54.318、42.425、42.141,P均<0.01）。结论 有氧运动可能有助于改善男性慢性精神分裂症患者的认知功能,包括信息处理加工速度、工作记忆、推理/问题解决能力、词语学习与记忆、视觉学习与记忆和执行功能。     

新冠肺炎流行期间安徽省青少年焦虑现状及影响因素

目的 探讨2019年新冠肺炎（COVID-19）流行期间安徽省青少年的焦虑现状及其影响因素，以期为后期进行针对性干预提供参考，保护青少年心理健康。方法 于2020年2月13日-19日，以网上问卷的形式采用自编的一般情况调查表、新冠肺炎相关认知调查表以及儿童焦虑性情绪障碍筛查量表（SCARED）对安徽省青少年进行调查，共收回有效问卷973份。结果 焦虑症状检出率为27.13%，其中男性SCARED中的广泛性焦虑评分较全国常模低［（3.31±3.53）分vs.（3.84±3.24）分］，男性社交恐怖评分较全国常模高［（4.35±3.43）分vs.（3.72±2.94）分］，女性躯体化评分［（4.25±4.59）分vs.（3.52±2.74）分］、社交恐怖评分［（5.52±3.55）分vs.（4.17±3.13）分］、学校恐怖评分［（1.18±1.58）分vs.（0.85±1.11）分］以及总评分［（18.99±13.83）分vs.（16.23±9.53）分］均较全国常模高，差异均有统计学意义（P<0.05或0.01）；单因素分析显示，性别、身体健康状况、第一次了解疫情的途径、负面消息占比以及不实信息占比会对焦虑症状检出率造成影响（P<0.05）；二元Logistic回归分析显示，女性（OR=2.04，P<0.01）、身体状况不佳（OR=2.12，P<0.01）、负面消息占比高（OR=4.28，P<0.01）是青少年焦虑的危险因素。结论 新冠肺炎流行期间，安徽省青少年社交恐怖程度普遍较高，其中女性、目前身体状况不佳以及负面信息占比高是其焦虑症状的危险因素。     

共病边缘型人格障碍的双相情感障碍患者认知功能状况

背景 双相情感障碍与边缘型人格障碍（BPD）共病率高,共病患者认知功能受损更严重。目的 探讨是否共病BPD的双相情感障碍患者认知功能的差异,为临床诊疗提供参考。方法 采用简单随机抽样,选取2021年4月-2022年4月在河北医科大学第一医院治疗的共病BPD的双相情感障碍患者60例（共病组）,其中双相抑郁患者33例,双相躁狂患者27例。同时选取双相情感障碍患者60例（未共病组）,其中双相抑郁35例,双相躁狂25例。采用中文版神经心理状态测验（RBANS）和Stroop色词测验评估患者的认知功能。结果 共病组RBANS中的即刻记忆、视觉广度、言语功能和总评分均低于未共病组,差异均有统计学意义（t=-2.356、-2.138、-3.306、-2.729,P<0.05或0.01）,Stroop色词测验中的单字时间、单色时间、双字时间和双色时间均长于未共病组,差异均有统计学意义（t=4.808、3.341、5.249、5.167,P均<0.01）。共病BPD的双相抑郁患者RBANS中的即刻记忆、视觉广度、言语功能和总评分均低于未共病BPD的双相抑郁患者（t=-2.446、-2.407、-2.231、-2.078,P均<0.05）,Stroop色词测验中的单字时间、单色时间、双字时间和双色时间均长于未共病组（t=3.652、3.035、4.406、5.016,P均<0.01）。共病组双相躁狂患者RBANS中的言语功能和总评分均高于未共病组（t=-2.777、-2.347,P<0.05或0.01）,Stroop色词测验中的单字时间、单色时间、双字时间和双色时间均长于未共病组（t=3.600、2.658、2.943、4.337,P<0.05或0.01）。结论 相较于未共病BPD的双相情感障碍患者,共病BPD的双相情感障碍患者认知功能受损更严重。     

帕金森病患者抑郁及生活质量的影响因素分析

目的 探讨帕金森病患者伴发抑郁的危险因素,分析影响帕金森病患者生活质量的主要因素。方法 纳入2018年6月至2020年5月在该院就诊的125例帕金森病患者。收集患者基本信息,采用相关量表评估患者运动及非运动症状。根据HAMD评分≥8分和<8分将患者分为抑郁组（89例）和非抑郁组（36例）。分析伴发抑郁的危险因素以及生活质量的主要影响因素。结果 单因素分析显示两组之间病程(z=-3.047)、等效剂量(z=-2.205)、UPDRSⅢ评分(z=-4.220)、H-Y分级(χ²=6.053)、SCOPA-AUT评分(z=-3.968)、MMSE评分(z=-3.359)、MoCA评分(z=-2.910)、PSQI评分(t=-3.985)、是否伴有EDS(χ²=9.089)、FS-14评分(z=-4.972)和KPPS评分(z=-2.949)比较,差异具有统计学意义(P<0.05)。多因素分析显示病程、SCOPA-AUT、MMSE和FS-14评分是抑郁的危险因素(P<0.05)。H-Y分级、UPDRSⅢ、SCOPA-AUT、MoCA和FS-14评分是生活质量的主要影响因素(P<0.05)。结论 病程、自主神经功能障碍、认知功能障碍和疲劳是帕金森病伴发抑郁的主要危险因素。运动症状、病情严重程度、自主神经功能障碍、认知功能障碍和疲劳是影响帕金森病患者生活质量的主要因素。 [引用格式:国际神经病学神经外科学杂志, 2021, 48(4): 327-332.]     

五行健康操对改善住院老年精神分裂症患者日常生活能力和认知功能的效果

目的 探讨五行健康操对改善住院老年精神分裂症患者日常生活能力和认知功能的效果。方法 纳入2016年5月-2017年5月在厦门市仙岳医院住院治疗、符合《国际疾病分类（第10版）》（ICD-10）诊断标准的老年精神分裂症患者（n=80）为研究对象,采用随机数字表法分为研究组和对照组各40例。两组均接受常规药物治疗、精神科护理及康复治疗,研究组在此基础上进行五行健康操练习。于干预前、干预6个月和干预1年后,采用Barthel指数评定量表（BI）评定患者日常生活能力,采用简易精神状态评价量表（MMSE）评定认知功能;于干预前和干预1年后,采用护士用住院患者观察量表（NOSIE）评定患者行为及病情变化。结果 干预6个月和干预1年后,研究组BI评分（F=2.876、3.240,P<0.05或0.01）和MMSE评分（F=4.742、7.902,P<均0.01）均高于对照组,差异均有统计学意义。干预1年后,研究组NOSIE各因子评分及总评分均高于对照组,差异均有统计学意义（t=0.173~2.463,P均<0.05）。结论 在常规药物治疗及常规护理的基础上实施五行健康操,可能有助于改善住院老年精神分裂症患者的日常生活能力和认知功能。     

抑郁障碍患者主观与客观认知功能的差异性研究

背景 抑郁障碍患者的主观认知功能与客观认知功能存在差异。目前,关于主客观认知功能差异影响因素的研究有限。目的 探索抑郁障碍患者主观和客观认知功能的差异及其影响因素,为进一步理解抑郁障碍患者认知功能受损情况提供参考。方法 纳入2022年1月13日—2023年12月11日在成都市第四人民医院门诊就诊或住院治疗的、符合《精神障碍诊断与统计手册（第5版）》（DSM-5）抑郁障碍诊断标准的77例患者为研究对象。采用蒙哥马利-艾森贝格抑郁量表（MADRS）评定患者抑郁症状严重程度,采用抑郁感知缺陷问卷（PDQ-D）和中国简版神经认知成套测验（C-BCT）分别评定患者的主观认知功能和客观认知功能,采用席汉残疾量表（SDS）评定患者的社会功能,以临床总体印象量表-疾病严重程度量表（CGI-SI）评定患者病情严重程度。采用Pearson相关分析考查年龄、受教育年限、MADRS总评分、SDS总评分、CGI-SI评分与主客观认知功能及其差异的相关性。采用多元线性回归探索主客观认知功能差异的影响因素。结果 是否用药的抑郁障碍患者PDQ-D总评分和主客观认知功能差异（D值）比较差异均有统计学意义（t=-4.228、-2.392,P<0.05或0.01）。抑郁障碍患者主观认知功能与客观认知功能的相关性无统计学意义（r=-0.148,P>0.05）;年龄和受教育年限与PDQ-D总评分均呈负相关（r=-0.333、-0.369,P均<0.01）,MADRS总评分、SDS总评分以及CGI-SI评分与PDQ-D总评分均呈正相关（r=0.487、0.637、0.434,P均<0.01）;年龄、受教育年限与D值均呈负相关（r=-0.411、-0.362,P均<0.01）,MADRS总评分、SDS总评分、CGI-SI评分与D值均呈正相关（r=0.259、0.468、0.299,P<0.05或0.01）。年龄（β=-0.328,P<0.01）和SDS总评分（β=0.409,P<0.01）是D值的预测因子。结论 抑郁障碍患者主观认知功能与客观认知功能的差异可能与年龄、受教育年限、症状严重程度以及社会功能受损相关。     

失眠的认知行为治疗对失眠障碍患者睡眠质量和认知功能的影响

背景 失眠障碍已成为当前社会的一种常见疾病,失眠的认知行为治疗（CBTI）是失眠障碍的非药物治疗方法之一,其对失眠障碍患者睡眠质量和认知功能影响的研究有限。目的 探索CBTI对失眠障碍患者睡眠质量和认知功能的影响,为失眠障碍的非药物治疗提供参考。方法 选取2021年1月-2022年10月在四川省精神卫生中心就诊、符合《精神障碍诊断与统计手册（第5版）》（DSM-5）诊断标准的47例失眠障碍患者为研究对象。患者接受为期6周的CBTI治疗。治疗前,采用汉密尔顿抑郁量表24项（HAMD-24）和汉密尔顿焦虑量表（HAMA）评定患者的抑郁和焦虑症状,在治疗前及治疗6周后采用匹兹堡睡眠质量指数量表（PSQI）和蒙特利尔认知评估量表（MoCA）评定患者的睡眠情况和认知功能。采用Spearman相关分析考查治疗后失眠障碍患者PSQI总评分减分值与MoCA总评分增分值的相关性。结果 治疗6周后,失眠障碍患者PSQI的主观睡眠质量、入睡时间、睡眠时间、睡眠效率、睡眠障碍、日间功能障碍因子评分及PSQI总评分均低于治疗前,差异均有统计学意义（t=5.569~15.290,P均<0.01）,MoCA的视空间与执行功能、命名、注意力、语言能力、抽象思维、记忆力因子评分及总评分均高于治疗前,差异均有统计学意义（t=-11.273~-4.277,P均<0.01）。Spearman相关分析显示,经6周CBTI治疗后,失眠障碍患者PSQI总评分减分值与MoCA总评分增分值呈正相关（r=0.323,P=0.027）。结论 CBTI可能有助于改善失眠障碍患者的睡眠质量和认知功能。CBTI干预后,失眠障碍患者睡眠质量的提高可能与认知功能的改善存在一定的关联。     

视频脑电图在小儿癫痫诊断中的应用

目的评价视频脑电图(video-EEG)在小儿癫诊断中的应用价值。方法对126例具有发作性症状的患儿进行连续8h的包括清醒、睡眠、诱发试验及必要的认知测验的视频脑电图监测。结果经发作期视频脑电图证实,39例初诊为癫性发作的患儿中14例(35%)为非癫性发作;15例其他症状发作中13例(86%)为非癫性发作。64例样放电患儿中51例(80%)确定发作类型,22例(34%)确定癫类型。视频脑电图可发现短暂轻微的癫发作及样放电引起的一过性认知损伤。结论视频脑电图在排除非癫性发作、确定癫性发作的类型、评价脑电-临床关系方面可提供准确可靠的证据,进一步提高癫的临床诊断水平。     

Neuroprotective properties of memantine in different in vitro and in vivo models of excitotoxicity

The pathogenesis of stroke, trauma and chronic degenerative diseases, such as Alzheimer's disease (AD), has been linked to excitotoxic processes due to inappropriate stimulation of the N-methyl-D-aspartate receptor (NMDA-R). Attempts to use potent competitive NMDA-R antagonists as neuroprotectants have shown serious side-effects in patients. As an alternative approach, we were interested in the anti-excitotoxic properties of memantine, a well-tolerated low affinity uncompetitive NMDA-R antagonist presently used as an anti-dementia agent. We explored in a series of models of increasing complexity, whether this voltage-dependent channel blocker had neuroprotective properties at clinically relevant concentrations. As expected, memantine protected neurons in organotypic hippocampal slices or dissociated cultures from direct NMDA-induced excitotoxicity. However, low concentrations of memantine were also effective in neuronal (cortical neurons and cerebellar granule cells) stress models dependent on endogenous glutamate stimulation and mitochondrial stress, i.e. exposure to hypoxia, the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP+) or a nitric oxide (NO) donor. Furthermore, memantine reduced lethality and brain damage in vivo in a model of neonatal hypoxia-ischemia (HI). Finally, we investigated functional rescue (neuronal capacity to migrate along radial glia) by memantine in cerebellar microexplant cultures exposed to the indirect excitotoxin 3-nitropropionic acid (3-NP). Potent NMDA-R antagonists, such as (+)MK-801, are known to block neuronal migration in microexplant cultures. Interestingly, memantine significantly restored the number of neurons able to migrate out of the stressed microexplants. These findings suggest that inhibition of the NMDA-R by memantine is sufficient to block excitotoxicity, while still allowing some degree of signalling.     

Storage of lipofuscin in neurons in mucopolysaccharidosis

Summary A histochemical and ultrastructural study was made on the brain of a 23-year-old man with Sanfilippo's syndrome. In accordance with previous reports the cortical nerve cells contained a PAS-positive lipid storage substance. This showed intense autofluorescence in UV-light and was positive with various stains for lipofuscin. The storage material appeared ultrastructurally as inclusion bodies composed of short lamellated membranes, granular material, and vacuoles. In addition, concentrically and transversely lamellated membranous cytoplasmic bodies were observed in the nerve cells. It is concluded that the PAS-positive lipid storage material in the neurons was composed partly of lipofuscin in addition to other lipids presumably glycosphingolipids.Supported by a grant from the Expressen Prenatal Research Foundation     

脑电图预测痫性发作研究进展

癫痫(epilepsy)是由脑部神经元高度同步化异常放电所致的临床综合征,系神经系统的常见病,困扰着全世界约1%的人群.每次神经元的阵发性放电或短暂的脑功能异常称为痫性发作(seizures).     

Role of vincristine in the inhibition of angiogenesis in glioblastoma

Objective: Vincristine, a microtubule-destabilizing drug, was found to exhibit anti-angiogenic effects and anti-tumoral activity. However, the precise mechanism by which vincristine inhibits angiogenesis in glioblastomas is not well understood. Our aim was to investigate whether vincristine affects vascular endothelial growth factor (VEGF) expression in glioblastoma cells and determine whether it is mediated by the downregulation of hypoxia-inducible factor-1α (HIF-1α).

Methods: We investigated the expression of HIF-1α in glioblastoma tissues resected from patients and in human glioblastoma cell lines using immunohistochemistry, Western blot analysis, and immunocytochemistry. In addition to an MTT assay assessing the effect of vincristine on cell proliferation and viability, the effects of vincristine on VEGF mRNA expression and HIF-1α protein were examined using real-time RT-PCR and Western blot analysis under 1% O₂ (hypoxia).

Results: HIF-1α was expressed in the majority of glioblastoma tissues and was detected mainly in the nucleus. Strong immunoreactivity for HIF- 1 α was found often in the hypercellular zones. Under hypoxic conditions, HIF-1α protein levels in the glioblastoma cell lines increased, primarily localizing into the nucleus similar to glioblastoma tissues. Exposure of glioblastoma cells to vincristine resulted in enrichment of the G₂-M fraction of the cell cycle, which suggests that vincristine-mediated growth inhibition of glioblastoma is correlated with mitotic inhibition. Using doses lower than those found to reduce the viability and proliferation of cells by 50% (IC₅₀), vincristine decreased both the expression of VEGF mRNA and the level of HIF-1α protein in hypoxic glioblastoma cells. In addition, following exposure to vincristine, the expression of VEGF mRNA was correlated with HIF-1α protein levels.

Conclusions: Our results suggest that the mechanism by which vincristine elicits an anti-angiogenic effect in glioblastomas under hypoxic conditions might be mediated, in part, by HIF-1α inhibition.     

自噬参与帕金森病发病的研究进展

近年来,蛋白质的降解障碍被认为是帕金森病（Parkinson’Sdisease,PD）发病过程中的重要因素,人们已经公认泛素一蛋白酶体系统（ubiquitin--pro—teasomesystem,UPS）功能异常或衰竭能够导致细胞内异常蛋白蓄积、细胞功能障碍,甚至细胞凋亡。与此同时,蛋白降解的另一条途径——自噬-溶酶体途径（autophagy—lysosomepathway,ALP）也已成为了生命科学领域的研究热点,自噬与神经变性疾病,尤其是PD的关系日益受到人们的重视。     

Midazolam in treatment of various types of seizures in children

Midazolam is a recently developed water-soluble benzodiazepine that shares anxiolytic, muscle relaxant, hypnotic and anticonvulsant actions with other members of this class. There are limited studies that midazolam can be used successfully to treat seizures in adults and children. In this study, 0.2 mg/kg intramuscular (IM) midazolam was administered to 11 children (eight boys and three girls), aged 3 days to 4 years (mean age 1.8±1.4 years), with seizures of various types. In all but one child, seizures stopped in 15 s–5 min after injection. No side effects were observed. These results suggest that IM administration of midazolam may be useful in a variety of seizures during childhood, especially in case of intravenous (IV) line problem.     

Developmental effects of in vivo and in vitro inhibition of nitric oxide synthase in neurons

The diffusible chemical messenger nitric oxide (NO) is involved in neuronal plasticity and it is, therefore, supposed to play a role in brain development. A shortage of NO during the critical period of brain maturation may theoretically have long-lasting consequences on the organization of the adult brain. We have performed in neonatal rats a chronic inhibition of the enzyme responsible for NO production, nitric oxide synthase (NOS), from postnatal day 3 to postnatal day 23, through administration of the competitive antagonist N-nitro-L-arginine methylester (L-NAME). The calcium-dependent catalytic activity resulted almost completely inhibited throughout the period of treatment and it took more than 4 days after its suspension to get a full recovery. The expression of the neuronal isoform of the enzyme (nNOS), revealed by immunoblotting, was unchanged during the treatment and after it. The histochemical reaction for NADPH diaphorase was reduced at the end of the treatment and recovered in concomitance with the recovery of the catalytic NOS activity. No gross structural alterations were detected in brain morphology. The levels of three neurotransmitter-related and one astrocytic marker were unchanged in the cerebellum, hippocampus and cortex of 60-day-old rats which had been neonatally treated. A similar lack of significant effects on neurochemical brain maturation was also noticed in a parallel series of experiments, in which a short pulse of NOS inhibition was performed at a critical prenatal time of brain development, from gestational day 14 to gestational day 19. In vitro, chronic exposure of cerebellar granule cells to L-NAME (500 microM) resulted in slight decrease of surviving neurons after 8 days in culture and in better resistance to the challenge of stressful culture conditions. The present results suggest that the basic plan of brain organization can be achieved despite an almost complete NOS inhibition during the maturation period. In vitro, NOS inhibition may bring to more pronounced consequences on neuronal viability and function.     

Characteristics of nociceptors in the periodontium--an in vitro study in rats

Recent studies have indicated that nociceptors can be classified into various types according to their physiological properties. These studies have clarified that the frequency distribution of various nociceptor types is different among body sites and animal species. In the present study, we investigated the physiological properties of rat's periodontal nociceptors in an in vitro jaw-nerve preparation. Responses were recorded from functional single filaments in the inferior alveolar nerve. To determine the nociceptor type, calibrated von Frey filaments, heat, and bradykinin (BK) stimuli were used. We found five subtypes of nociceptors in the periodontal ligaments of the lower incisor: Adelta-high threshold mechanonociceptors (Adelta-HTM, n=28), Adelta-mechanoheat nociceptors (Adelta-MH, n=6), Adelta-polymodal nociceptors (Adelta-POLY, n=26), C-high threshold mechanonociceptors (C-HTM, n=3) and C-polymodal nociceptors (C-POLY, n=4). Most nociceptors were Adelta-innervated, while only a small number of C-innervated nociceptors were found. The present results suggest that periodontal nociceptors transmit mainly fast pain, and may thus play a role in rapid detection of injure-related stimuli during mastication.