Total content of RNA in individual nerve cells of spinal ganglion during ischemia in dogs

The total RNA content in the individual nerve cells of the lumbal spinal ganglia in the dog after the 80 minutes lasting partial ischemia was followed. The spinal ganglion neurons did not react in ischemia in the same way. The total RNA content in the individual neurons of the control animals occurred in the range 132-990 arbitrary units, after the ischemia in the range 116-670 arbitrary units. In both groups the cells with the low or high RNA content were seen. The decreases in total RNA content after ischemia was at the higher level of the statistical significance in the group with the largest and middle large neurons giving the evidence about the greater sensitivity to the oxygen shortage in comparison with the group of the smallest spinal ganglion nerve cells.     

Strain differences in pituitary beta-endorphin and ACTH content in inbred mice

The whole pituitary contents of beta-endorphin and ACTH were found to vary widely among 5 inbred strains of mice. beta-endorphin values were 2.5-fold different and ACTH values 1.5-fold. Strains low in beta-endorphin were also low in ACTH. The existence of genetic differences raises the possibility that there exist, or can be developed, strains with extremely low or high levels of these peptides that would aid research directed at elucidating the physiology of opioid peptides.     

Interstrain differences in the total RNA content in brain cells of the laboratory rat

Total content of the ribosomal RNA in the cells of the frontal cerebral cortex (FCC), the septum (S), the dorsal hippocampus (DHI) and the lateral and medial hypothalamus (LHY, MHY) in adult males of the laboratory rat was determined cytophotometrically in two albino strains (i.e. in the Wistar strain (W) and in a strain with spontaneous hypertension (SHR) derived from the former) and in two pigmented strains (i.e. in the Long Evans strain (LE) and in the Brattleboro strain with spontaneous diabetes insipidus (DI) derived from the latter). The used quantitative histochemical method turned out to be very sensitive and demonstrated considerable differences in all brain structures examined. The LE strain showed higher values than the W strain in the FCC, S, DHI and LHY cells and lower ones in the MHY cells. The SHR strain was identical with the W strain from which it originated only in the FCC cells; in the S, DHI, and LHY cells it exhibited higher values, in the MHY cells lower ones. In the DI strain all values agreed with those of its original LE strain in all the areas evaluated except in the S and MHY cells where the values were lower. The data evaluated by stepwise discriminant analysis were found to be exceptional in the W strain. The data for the SHR strain were closer to the LE and DI strains, the data for the LE and DI strains intermingled.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同血清培养条件下骨髓间充质干细胞的增殖

背景：目前,分离培养骨髓间充质干细胞应用最为广泛的细胞生长添加剂是胎牛血清/小牛血清,应用脐血清进行骨髓间充质干细胞培养的相关研究较少。 目的：观察不同血清培养对骨髓间充质干细胞增殖的影响。 方法：用Ficoll密度梯度离心法分离纯化骨髓间充质干细胞,在含脐血清、胎牛血清以及无血清的L-DMEM培养基中培养,观察各组细胞形态、增殖情况;应用流式细胞术对细胞表面抗原CD34、CD44、CD45、CD105进行表型鉴定。 结果与结论：脐血清培养后细胞形态较小,似纺锤状,细胞呈网状生长;胎牛血清培养后细胞呈梭形成纤维细胞样,呈集落样生长;脐血清和胎牛血清均能促进细胞生长增殖,但骨髓间充质干细胞在脐血清中增殖更活跃,无血清培养基本无增殖。流式细胞鉴定显示CD34、CD45阴性,CD44、CD105阳性,脐血清扩增后骨髓间充质干细胞的表面标记无明显改变。     

Genetic control of dopamine and serotonin receptors in brain regions of inbred mice

In this report the genetic determinants of dopamine and serotonin receptors are investigated. We have used two types of radioreceptor binding assays to identify and quantify these neurotransmitter receptors in various brain regions of inbred mice. In the first method dopamine and serotonin sites are quantified using [3H]spiperone in the presence of appropriate blanking agents. These results are compared with those obtained by the use of [3H]domperidone and [3H]mianserin to label D2 and S2 sites, respectively. Both methods yield nearly identical results. Strain differences in D2 sites are found in the striatum, olfactory tubercle and pituitary. The density of dopaminergic sites is uncorrelated in the 3 brain regions in all mouse strains studied, suggesting that genetic determination of receptor density is independently regulated in each region. Similar observations have been made for S2 receptors in the striatum, hypothalamus, olfactory tubercle and frontal cortex. Analysis of D3 and D2 binding sites in recombinant inbred lines suggests that each site may be determined monogenically.     

Studies on AMP deaminase and 5'-nucleotidase in rat brain under different experimental conditions

Adenosine monophosphate (AMP) deaminase and 5'-nucleotidase, the two enzymes involved in the disposal of AMP, have been detected in different regions of normal rat brain and in animals subjected to heightened neuronal activity (leptazol-induced convulsions) and to depression of the central nervous system (CNS) by the administration of barbiturates. They have also been estimated in the CNS of animals subjected to anoxia or treated with lithium and ammonium salts. The AMP deaminase activity was found to be highest in cerebellum and lowest in cerebral cortex, while the 5'-nucleotidase activity was found to be highest in brain stem and lowest in cerebellum. The AMP deaminase activity was elevated in all the regions of brain during the preconvulsive and convulsive periods. The activity returned to normal during recovery. The activity of 5'-nucleotidase was found to be depressed in the preconvulsive and post-convulsive periods. The enzyme was also found to be depressed in all the three regions after the administration of barbiturates. Administration of lithium or ammonium salts of induction of anoxic states resulted in an increase in the activity of AMP deaminase in all the three regions of brain. These results are discussed in relation to the probable production of cyclic AMP and cyclic guanosine monophosphate (GMP) which may have depressive and excitatory roles, respectively, in brain. It appears that increased AMP deaminase activity is associated with increased neuronal activity while depression of 5'-nucleotidase activity is associated with conditions of decreased CNS excitability.     

Spontaneous saccades under different visual conditions in the pigeon.

Spontaneous saccades of both eyes were recorded in head-restrained pigeons placed in 6 different visual conditions (darkness and biocular, uniocular, frontal or lateral viewing). Most saccades (95%) were biocular and directed forward (around the beak axis) and backward (around the horizontal line). In the dark, the proportions of forward and backward saccades were different, they became symmetrical when the visual input involved either the left eye, the lateral fields or both eyes. This spatial reorganization could be mediated by one 'dominant' eye through the lateral and foveal vision. Although some biocular saccades were strictly convergent, divergent or conjugate, most of them showed a higher independence since they had different directions and amplitudes for each eye.     

Mast cells in the rat brain and changes in their number under different light regimens.

The BD III strain rats were raised from birth either in a day-night light cycle (14:10 h) or in complete darkness for 3 months. At that age the animals were either killed or exposed to a reversed light regimen for an additional 5 days. Mast cells (with cytoplasmic granules metachromatically stained by toluidine blue) were rare but regularly present both in the parenchyma and leptomeninges of the diencephalic part of the brain stem in all experimental groups. They were often localized in close proximity to blood vessels and distributed over the entire cross-sectional area with an apparent dorsolateral maximum. Rearing of rats from birth in complete darkness for 3 months led to a significant increase in the number of mast cells in the dorsal part of the lateral geniculate body (dLGB) and leptomeninges overlying the dorsolateral part of the brain stem (+138 and +250%, respectively). The increase could be induced, and also partly reversed (especially in the dLGB), by 5-day exposure of 3-month-old animals to darkness or to normal day-night light conditions. The data indicate a close relationship between the number of mast cells and the functional state of the brain.     

Immunochemical studies of brain glutamate decarboxylase and GABA-transaminase of six inbred strains of mice

Six different inbred strains of mice (C57BL/6J, CBA/CaJ, CE/J, DBA/2J, LP/J and RF/J) were compared in terms of specific activities and immunochemical properties of brain L-glutamate decarboxylase (GAD) and gamma-aminobutyrate transaminase (GABA-T), the enzymes responsible for the synthesis and degradation of GABA, respectively. GAD from the brains of the different strains was indistinguishable on the basis of specific activities, double diffusion tests, immunoelectrophoresis and inhibition by antibody. However, microcomplement fixation tests showed GAD from DBA and C57BL mice to be most distinctly different from GAD extracted from the Swiss mouse, from which the original antigen was prepared and that the enzyme from the CE, LP and RF also differed. Similar fixation curves were obtained for the GAD from CBA and Swiss mice. GABA-T from the different strains was indistinguishable on the basis of all the tests employed.     

Developmental variations of brain serotonin, tryptophan, 5-hydroxyindole acetic acid, and noradrenaline and dopamine content in two inbred strains of mice

Endogenous levels of tryptophan (TRP), serotonin (5-HT), 5-hydroxyindol acetic acid (5-HIAA), noradrenaline (NA) and dopamine (DA), were measured in the brain-stem and anterior regions of C57BL and BALBc mice whose ages ranged from 1 day postnatal to 12 weeks. In C57BL mice levels of NA were found to be higher in the brainstem from week 1 onwards (except at week 3), and in the anterior region from week 6 onwards than in BALBc mice. 5-HT levels were found to be higher in C57BL mice from day 1 to week 2 in the brain-stem, and in the anterior region at week 1 and from week 5 onwards, compared to BALBc. The evolution of DA levels in the anterior region shows opposite differences before and after week 3-4. Before week 3 lower levels of DA were found in C57BL mice and the reverse is observed from week 5 onwards. Moreover during the postnatal development, the variation of the different components of the serotoninergic metabolism (TRP, 5-HT, 5-HIAA) is similar to that observed in other species.     

Acetylcholine content in different regions of the rat brain

Acetylcholine content of different rat brain regions was measured. A correlation between acetylcholine content and cholineacetyltransferase (ChAc) activity in discrete brain regions was found. However there are regions such as cerebellar nuclei, cerebellar hemisphere, caudal medial forebrain bundle, zone incerta, nucleus vestibularis lateralis where the acetylcholine content is relatively much higher than the ChAc activity, and regions such as n.cochleares, n.motor n.V., N.motor N.VII., n.motor, n.XII where ChAc activity was high and the content of acetylcholine is relatively low.     

Altered brain copper and zinc content in quaking mice

Brain copper and zinc levels were determined in 21-day-old and "adult" C3HeB/FeJ quaking mice and in normal littermate controls. Expressed per gram dry weight of brain, copper was increased 84% over normal mice at 21 days after birth, but was not significantly different from normal in the adults. Zinc was increased 23 to 24% at both ages. At both ages, brains from quaking mice had a significantly reduced content of solids, indicating increased water content in the mutant brain. Our study is the first to report copper and zinc content as a measure of both wet and dry brain weights. Our results indicate abnormal copper content in the quaking mutant. The relationship between copper content and other aspects of the quaking phenotype, including its seizure behavior and myelin deficit, remain to be established.     

Stability of the mismatch negativity under different stimulus and attention conditions.

OBJECTIVE: Mismatch negativities (MMN) elicited by frequency and duration changes in a sequence of repetitive tones were recorded in test and retest sessions from 45 subjects. METHODS: Tones presented with a stimulus onset asynchrony (SOA) of 0.5 s were to be ignored while attention had no instructed focus in one group and was directed to an active visual vigilance task in a second group of subjects. RESULTS: MMN amplitude was larger for duration deviants, the focus of attention had no systematic effect. Individual replicability of the MMN amplitudes was generally better when duration deviants were used. In addition, directing attention to the visual task increased the retest reliability of the duration deviance MMN. In this condition, the test-retest correlation coefficients were above 0.8 at all frontal scalp sites (0.87 at F4). CONCLUSIONS: The study shows that the deviant type as well as the attentional condition may have substantial effects on the stability and replicability of MMN potentials. The choice of the appropriate task condition is essential for using the MMN in group comparisons and as a diagnostic tool in individual cases.     

不同条件下光动力治疗对C6胶质瘤细胞的作用

目的 分析不同条件下应用血卟啉衍生物(HpD)的光动力学疗法(PDT)对体外培养大鼠C6胶质瘤细胞的作用.方法 MIT法检测PDT后C6细胞的生存率:(1)不同HpD浓度组(0、2、5、10、20、30及40 mg/L)C6细胞PDT(628 nm、20 mW/cm2、照光5 min)后的生存率;(2)C6细胞分别与不同浓度HpD(0、5、10、20、30及40 mg/L)孵育不同时间(0.5、1、3、6、12及24 h)行PDT(628nm,20 mW/cm2)后的生存率;(3)不同照光强度下(10、20及30 mW/cm2)PDT后C6细胞的生存率.结果 不同条件下PDT治疗对C6细胞的作用不同:(1)当HpD浓度低(2mg/L)、HpD与细胞孵育时间短(<3 h)时不能对细胞产生抑制或杀伤效应;(2)PDT后C6细胞的生存率随着HpD浓度的升高而降低,随着细胞与HpD孵育时间的延长而降低(>12 h后各组间差异无统计学意义),随着照光强度的增强而下降(20与30 mW/cm2之间差异无统计学意义).结论 HpD介导的PDT对体外培养大鼠C6胶质瘤细胞的作用与HpD浓度、HpD与细胞孵育时间及照光强度等有关,在不同条件下可表现为促进肿瘤细胞生长或杀伤肿瘤细胞的作用.     

Genetic analysis of serum thyroxine content and audiogenic seizures in recombinant inbred and congenic strains of mice

We previously proposed that the audiogenic seizure (AGS) susceptibility of 21 +/- 1-day-old DBA/2 (D2) mice may result from an early postnatal elevation in serum thyroxine (T4) concentration. In the present study we used seven C57 X DBA (BXD) recombinant inbred strains and the D2.B6-Iasb congenic strain to study the association between serum T4 content and susceptibility to AGS. The D2.B6-Iasb congenic mice are genetically similar to the D2 mice except for the Iasb gene, which inhibits AGS susceptibility. The total and estimated free serum T4 concentrations in these strains at 14 +/- 1 days of age were compared with the previously determined AGS susceptibilities of these strains at 21 +/- 1 days of age. We found no significant correlations between serum T4 concentration and AGS susceptibility in these strains. It is unlikely, therefore, that inherited differences in neonatal serum T4 content are directly responsible for differences in susceptibility to AGS in 21 +/- 1-day-old mice. The mechanisms by which the experimental manipulation of serum T4 content influences AGS susceptibility are discussed.     

Strain differences in pituitary β-endorphin and ACTH content in inbred mice

The whole pituitary contents of β-endorphin and ACTH were found to vary widely among 5 inbred strains of mice. β-endorphin values were 2.5-fold different and ACTH values 1.5-fold. Strains low in β-endorphin were also low in ACTH. The existence of genetic differences raises the possibility that there exist, or can be developed, strains with extremely low or high levels of these peptides that would aid research directed at elucidating the physiology of opioid peptides.     

RNA content and volume of nerve cell bodies in human brain. II. Subiculum in aging normal patients.

The subiculum of the hippocampal formation was sampled from 16 patients aged 8 months to 94 years at postmortem examination. An analysis of 960 single nerve cell bodies dissected from the subiculum showed a significant difference in the RNA content, the volume, and the RNA concentration measured at different ages. Both the neuronal RNA and the volume showed an adult value at 9 years of age and remained unchanged until 52 years of age. The mean RNA content and the volume was 44 pg and 5271 μm³, respectively, during this period. A high neuronal RNA content was a characteristic feature of the subiculum in patients between the ages of 56 and 94 years. The onset of increased neuronal RNA coincided with an appearance of neurofibrillary tangles in the subiculum, implying that the substantial increase in RNA content may be related to subsequent synthesis of the neurofibrillary protein, which accumulates as neurofibrillary tangles.