Change of the human taste bud volume over time

Objective

The specific aim of this study is to measure the taste volume in healthy human subjects over a 2.5-month period and to demonstrate morphological changes of the peripheral taste organs.

Material and methods

Eighteen human taste buds in four fungiform papillae (fPap) were examined over a 10-week period. The fungiform papillae investigated were selected based on the form of the papillae or the arrangement of surface taste pores. Measurements were performed over 10 consecutive weeks, with five scans in a day once a week. The following parameters were measured: height and diameter of the taste bud, diameter of the fungiform papilla and diameter of the taste pore.

Results

The findings of this exploratory study indicated that (1) taste bud volumes changed over a 10-week period, (2) the interval between two volume maxima within the 10-week period was 3–5 weeks, and (3) the diameter of the fPap did not correlate with the volume of a single taste bud or with the volume of all taste buds in the fPap within the 10-week period.

Conclusions

This exploratory in vivo study revealed changes in taste bud volumes in healthy humans with age-related gustatory sensitivity. These findings need to be considered when studying the effect of denervation of fungiform papillae in vivo using confocal microscopy.     

丙烯腈对体外培养鼠胚胎肢芽细胞增殖分化的研究

目的：研究丙烯腈(actylonitrile,ACN)对大鼠胚胎肢芽细胞增殖分化的影响。方法：13d的大鼠胚胎脊髓组织,经取材、分离、消化后作原代细胞培养,加入不同浓度的ACN0．01,0．1,1．0,10．0,50．0,100．0,200．0μg／ml,从细胞形态学及细胞计数角度观察细胞生长与分化过程,同时测定蛋白质含量、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性并与对照组进行比较。结果：各组ACN明显抑制胚胎肢芽细胞的增殖和分化,集落形成率明显减少,细胞体积小;其半数分化抑制剂量(ICD50)为29μg／ml,半数存活抑制剂量(ICV50)为42μg／ml,均显示剂量效应关系。结论：ACN能抑制胚胎肢芽细胞增殖和分化,可能与其能抑制蛋白质合成,并引起脂质过氧化有关。     

骨形成蛋白-2、4在胎鼠牙胚蕾状期的表达

目的:观察生长因子骨形成蛋白-2、4(BMP-2、4)在牙胚蕾状期的表达,探讨二者的作用及其关系,为牙组织工程研究打下基础。方法:选取14 d SD胎鼠下颌第一磨牙牙胚做石蜡切片,HE染色光镜观察证实牙胚处于鼠胚胎第14天蕾状期后,则取其前后2~3张切片用免疫组化LsAB法检测BMP-2、4在鼠牙胚蕾状期的分布与表达。结果:BMP-4在蕾状期牙上皮和牙间质均有表达;BMP-2在牙上皮有表达而在牙间质表达不明显。结论:BMP-2、4在牙胚蕾状期表达模式相似,但BMP-2的表达比BMP-4晚,反映二者作用各有侧重又相互联系。     

平移计数法在微团培养技术中的应用

背景与目的： 探索一种经济、快速而又准确的计数方法,以应用于微团培养技术中集落的评价。 材料与方法： 采用5 d连续培养妊娠13 d的大鼠胚胎中脑及肢芽细胞后,以倒置显微镜视场直径为间距将微团划分为若干等间距平行区间,沿一定方向移动视场并依次计数各区间内集落数,通过摄像分析和批内重复实验评价方法的准确度及灵敏度。 结果： 各组数据经Grubbs检验法检验均为正常数据,中脑细胞集落数和肢芽细胞集落数的相对误差分别为0.776％、0.213％;批内标准差分别为0.933 9、2.883 9;批内变异系数分别为1.24％、2.05％,均小于WHO提出的OCV(3％)标准。 结论： 平移记数法无需特殊设备,不仅具有较好的准确度和极高的灵敏度,而且适用于即时分析,从而缩短实验周期,可以作为微团培养技术中集落计数的常规方法。     

醋酸锌对大鼠胚胎肢芽细胞增殖和分化影响的研究

目的　研究醋酸锌对原代培养的大鼠胚胎肢芽细胞形态、细胞相对蛋白含量、细胞集落形成率以及肢芽细胞生长发育的影响。方法　取SD大鼠胚胎肢芽组织,分别加入不同浓度的醋酸锌进行体外原代微团培养。用光学显微镜观察细胞形态,在倒置相差显微镜下计数细胞集落数,同时用Folin-酚法检测细胞蛋白含量。结果　当锌浓度为0.05mmol/L时,对肢芽细胞生长和集落的形成无显著影响,而当锌浓度增至0.1mmol/L时,表现出显著促进作用,锌浓度大于1.0mmol/L时则呈现抑制作用,且影响的程度随着锌浓度的增加而增强。醋酸锌对大鼠胚胎肢芽细胞的半数分化抑制浓度(ICD50)为1360.9μg/mL。结论　醋酸锌对胚胎肢芽细胞增殖和分化的影响呈现双向效应,即低浓度促进,高浓度抑制。     

天麻的组织培养及快速繁殖

目的：利用组织培养方法快速繁殖成米麻作为种麻,为寻找出一简便可行的快繁天麻种麻的新途径提供理论依据。方法：天麻块茎或茎尖无菌离体培养,米麻块茎诱导培养基为1／2MS＋6－BA 1mg/L NAA0.5mg/L＋香蕉50mg/L;箭麻茎尖诱导培养基为1／2MS＋6－BA2mg/L NAAO.2mg/L。结果：小米麻经50d无菌培养后开始生长出新米麻,70d后原小米麻块茎上生长出多个分枝的新米麻;箭麻茎尖超过140d组织培养,茎尖分化、诱导形成原球茎,超过160d培养原球长大并开花。结论：天麻可以用组织培养方法快速繁殖成米麻作为种麻。     

辛夷挥发油的抗炎、抗过敏作用

辛夷挥发油腹腔注射(50,100mg/kg)能明显对抗二甲苯所致小鼠耳廓肿和蛋清所致的大鼠足跖肿。辛夷挥发油(20,30,40mg/ml)能对抗SRS-A、HA所致的豚鼠离体回肠的收缩作用,并能对抗致敏豚鼠回肠的过敏性收缩,这证明辛夷挥发油具有明显的抗炎、抗过敏作用。     

Ultrastructural localization of cholinesterase uring chondrogenesis and myogenesis in the chick limb bud

Summary Cholinesterase (ChE) is transiently expressed in undifferentiated embryonic cells. In the chick limb bud ChE-activity was found in the apical ectodermal ridge and in the subridge mesenchyme. The reaction was localized in the perinuclear cisterna, in an extensive network of narrow profiles of endoplasmic reticulum (ER), and in the Golgi complexThe chondroblasts emerging from the subridge mesenenyme, also showed strong ChE-activity. During differentiation the enzyme first disappeared from the Golgi zone. Then, the narrow ChE-positive ER was successively replaced by ChE-negative extended rough ER characteristic for the differentiated chondrocyte.The myoblasts showed weak ChE-activity with the same ultrastructural localization as in other mesenchymal cells. After fusion the myotubes exhibited strong ChE-activity in the perinuclear cisterna and the developing sarcoplasmic reticulum. In later stages of myogenesis the myoblasts were closely attached to the myotubes and had lost their ChE-activity.During mitosis of ChE-positive cells, ChE-activity was retained in fragments of perinuclear cisterna and ER. In ChE-active mesenchymal cells and chondroblasts we observed specialized contact zones between ER and plasma membrane. ChE-active cisternae of ER run parallel to the plasma membrane with a gap of approximately 10–15 nm. We discuss a possible function of a cholinergic system during morphogenesis.