聚丙烯酰胺凝胶电泳分析615纯系小鼠血清蛋白

目的：根据各种蛋白质在一定的泳动条件下,都有一定的相对迁移率不同的特点,分析６１５ 纯系小鼠血清中的蛋白质在聚丙烯酰胺凝胶上的分布,进行了定位分析。方法：采用高ｐＨ 不连续性聚丙烯酰胺凝胶电泳及蛋白质特殊染色法。结果：６１５ 鼠血清蛋白质在聚丙烯酰胺凝胶上可分离出１３ ～１５ 条区带,脂蛋白３ 条、白蛋白２ 条、糖蛋白５ 条、铜蓝蛋白１ 条、血红蛋白１ 条、结合珠蛋白３ 条。根据每种蛋白质的Ｒｍ 值定位顺序从阳极到阴极依次为１ ．糖蛋白、２．脂蛋白、３ ．白蛋白、４．脂蛋白、５ ．糖蛋白、６ ．巨球蛋白（ 根据其它资料） 、７ ．铜蓝蛋白、８ ．结合珠蛋白、９ ．Ｈｂ、１０ ．运铁蛋白（ 根据其它资料）、１１ ．脂蛋白、１２ ～１４ ．均为糖蛋白。光密度扫描６１５ 鼠血清蛋白质相对面积比分别为白蛋白为４８－４、α１ 球蛋白为６－９、α２ 球蛋白２３－８ 、β球蛋白为５－０ 、γ球蛋白为１３－８ 。结论：６１５ 鼠血清蛋白质的定位分析对于６１５ 鼠可移植性淋巴细胞型白血病鼠的蛋白质研究具有一定的实际意义,利用Ｒｍ 值来作蛋白质定位分析简单易行,关键在于掌握实验条件的恒定。     

Differentiation of Embryonic Stem Cells into Neurons and Retina—like Structure in Nude Mice

Purpose: To investigate the intraocular growth and biological characteristics of mice embryonic stem cells in nude mice.Methods: Murine embryonic stem cells (D3 cell line) were cultured and maintained in an undifferentiated state in vitro, then transplanted into the anterior chamber of nude mice. Mophological and immunohistochemical examinations were implemented. Results: Two to three days after transplantation, yellow-white floating granules, sheets and masses were seen inside the anterior chamber and vitreous cavity, and enlarged gradually. 14 - 20 days later, the mice were executed. Morphological examination showed that there were undifferentiated cells and some round or polygonal differentiated cells in anterior chamber and vitreous cavity. The morphology of these differentiated cells were similar to that of the retina. The cells were highly positive in NSE staining. Conclusion: The tranplanted embryonic stem cells could grow in the eyes of nude mice with tendency to differentiate into neurons and r     

Strain-dependent effects of cocaine on memory storage improvement induced by post-training physostigmine

Post-training administration of the inhibitor of cholinesterase enzymes, physostigmine, dose-dependently (0.025–0.4 mg/kg) improved retention of an inhibitory avoidance response in C57BL/6 (C57) as well as in DBA/2 (DBA) mice, the latter being more responsive than C57 mice. The effects on retention performance induced by physostigmine in C57 and DBA mice appeared to be due to an effect on memory consolidation. In fact, they were observed when drugs were given at short, but not long, periods of time after training, which is when the memory trace is susceptible to modulation. Moreover, these effects are not to be ascribed to a rewarding or non-specific action of the drugs on retention performance, as the latencies during the retention test of those mice that had not received a footshock during the training were not affected by the post-training drug administration. Post-training administration of cocaine (1–5 mg/kg) dose-dependently improved retention of an inhibitory avoidance response in C57 mice, while impairing it in the DBA strain, thus confirming previous results (Puglisi-Allegra et al. 1994b). Pretreatment with cocaine at ineffective doses as well as at an effective one potentiated the effects of an ineffective as well as of an effective dose of physostigmine in C57 mice, while it antagonized the effects of the inhibitor of cholinesterase enzymes on memory consolidation in DBA mice. The present results indicate that the indirect DA receptor agonist cocaine affects physostigmine action on memory consolidation in an opposite manner in the two inbred strains, pointing to genotype-dependent interaction between cholinergic and dopaminergic activity in memory consolidation.     

Excretion of modified nucleosides during development of malignant lymphomas in mice after whode body irradiation

Summary During x-ray-induced development of malignant lymphomas in mice their urinary excretion of eight modified nucleosides was monitored and the values were compared to the results of the histological examination of the animals at time of their sacrifice.It was found that the pathologically augmented excretion of modified nucleosides begins as much as several weeks before the malignant lymphomas can be diagnosed clinically. Thus some mice had increased levels of modified nucleosides even 10 weeks before sacrifice, though at the time of sacrifice the histological investigation reveled only some small foci of reticulum cell neoplasm in their spleen.It is therefore stressed that the usefulness of the determination of urinary modified nucleosides as an early noninvasive screening test for cancer in man and as an in vivo carcinogenicity test should be evaluated.Abbreviations pseudouridine - m¹A 1-methyladenosine - m⁵C 5-methylcytidine - m¹I 1-methylinosine - m¹G 1-methylguanosine - m²G N ²-methylguanosine - m²G N ²,N²-dimethylguanosine - ac⁴C N ⁴-acetylcytidine - mt⁶A N-(9--d-ribofuranosylpurine-6-yl)N-methylcarbamoyl) threonine - acp³U 3-(3-amino-3-carboxypropyl) uridine - SD standard deviation     

A genetic analysis of the hyperthermic response to d-amphetamine in two inbred strains of mice

A genetic analysis of amphetamine-induced hyperthermia was conducted in inbred mice of the strains Balb/c and C₃H and in their F₁F₂ and backcross generations. The results of biometric analysis indicate that the effect of amphetamine on body temperature is genetically determined. The mode of inheritance characterized by a partial dominance (Balb/C over C₃H strain). However, a possible matermal effect of C₃H can overcome the dominant effect in male progenies and inhibit amphetamine hyperthermic effect.     

Behavioral effects of hashish in mice

The acute and subchronic effects of hashish extract (20 mg ⁹-THC/kg) on the social interactions between two drug-treated residents and an untreated intruder male were investigated. In this analysis 28 different behavioral elements were recorded.A single drug application suppressed all categories of behavior, except submissive behavior and flight, in dominant and subordinate residents. Treated animals were less active than controls and immobility was very frequent. An elevated total activity, due to an increase in non-social activities, was observed in the untreated intruder males of this group. Social investigation as well as submissive behavior and flight were reduced in these animals.On introduction of an untreated male after the fourth drug treatment of the residents, the drugged males showed tolerance to the sedative and most of the other behavioral effects of the drug, and intruder males behaved quite normally.The formation of a dominant-subordinate relation within the group was influenced neither by a single nor by repeated drug treatment.The acute and subchronic effects of hashish extract on social, especially aggressive behavior of males are compared to those described in previous papers and the variation in the results of the different studies is discussed.     

Free amino acid pool in the brain of mice homozygous for the gene "dilute lethal"

The neurologic mutant "dilute lethal" (dl) mice, which reveal several neurologic and biochemical disturbances similar to human phenylketonuria, were used to investigate some aspects of amino acid disorder. We have studied the free amino pool in the brain of "dl" mice and of their control littermates as well as phenylalanine and tyrosine levels in brain and liver as a function of age and after phenylalamine overload. The tyrosine level decreased in brain and liver of affected mice whereas the phenylalanine/tyrosine ratio increased as a function of age. The significantly higher phenylalanine level and phenylalanine/tyrosine ratio in the liver of 20-day-old "dl" mice suggest a lower liver phenylalanine hydroxylase activity. After phenylalanine overload, the impairment of phenylalanine metabolism is predominant in the brain of "dl" mice, suggesting a disturbance in phenylalanine hydroxylation. A decrease in the level of several amino acids occurs in the brains of "dl" mice without or after phenylalanine overload; these facts might correspond to a disturbance in the transfer of amino acids to the brain and may lead to impairment in protein synthesis.     

Dysregulation of the Hypothalamus-Pituitary-Adrenal Axis in Male and Female, Genetically Obese (ob/ob) Mice

The autosomal, recessive obesity of ob/ob mice is associated with hypercorticosteronemia and amelioration of most symptoms of obesity following adrenalectomy. Increased adrenocorticotropic hormone (ACTH) secretion has been hypothesized on the basis of several reports of higher pituitary ACTH content in ob/ob mice compared to lean littermates. However, the only measurement of ACTH blood concentration found lower levels in ob/ob mice than in leans suggesting that hypercorticosteronemia might result solely from an enhanced adrenal response to ACTH and also suggesting that the ob/ob's elevated pituitary ACTH content might be due to decreased ACTH secretion rather than increased ACTH synthesis. In our study, basal serum ACTH levels were higher in ob/ob males and females compared to sex-matched lean littermates. Anterior pituitary ACTH synthesis was also elevated as indicated by increased content of ACTH and proopiomelanocortin mRNA in obese mice of both sexes; however hypothalamic corticotropin-releasing factor content was not different in lean and obese mice. Basal serum ACTH and corticosterone (CS) levels showed normal circadian rhythm in both phenotypes and sexes, but the circadian increase in CS level was much greater in obese mice than in leans despite equal serum ACTH increases in the two phenotypes. Ether stress at both peak and trough of the circadian rhythm also stimulated much larger serum CS increases in obese mice even though ACTH increases were again equal in the two phenotypes. Taken together, these results strongly indicate that ob/ob mice have increased synthesis and secretion of pituitary ACTH despite the presence of chronically elevated serum CS. This hyperactivity of the hypothalamo-pituitary-adrenal axis appears to be most pronounced in ob/ob females since pituitary ACTH content was equal in obese males and females despite much higher circulating CS levels in the females. Furthermore, the results also indicate an enhanced response to ACTH by the adrenal cortex of the obese mouse. Thus, ob/ob mice exhibit abnormal hypothalamo-pituitary-adrenal axis function with hyperactivity occurring at the level of pituitary ACTH synthesis/secretion as well as at the level of adrenocortical response to ACTH.     

In vivo evaluation of cell mediated immunity against human melanoma

Evaluation of cell mediated immunity against human melanoma target cells was performed in an in vivo model using human tumor xenografts growing in Balb/c athymic mice. Intraperitoneal inoculation of 1 × 10⁷ human melanoma cells produced peritoneal carcinomatosis which lead to death of the animals at 23.8 ± 2.6 days (N = 12). Peripheral blood lymphocytes (PBL) from normal donors were administered to tumor bearing mice, and survival times of 22.0±2.3 days were observed (N = 8). Peripheral blood lymphocytes from four of five normal donors which had been presensitized on monolayers of melanoma tissue culture cells in vitro failed to prolong host survival times. In contrast, PBL obtained from 15 of 20 melanoma patients were found to prolong survival of the tumor bearing nude mice. Of these 15 patients, 8 were undergoing specific active immunotherapy, while 7 had not been sensitized except by the disease process. The ability of PBL obtained from patients to prolong survival of tumor bearing animals did not appear to correlate with either the stage of the disease or the patient's clinical course. The possible mechanisms for the prolonged survival and usefulness of this model are discussed.     

The relative ethylumbelliferone dealkylase activity characterizing the effect of different inducers on the hydroxylase system in the liver musomes of female mice

d,l-Camphor was detected as a new inducer of hydroxylase in the liver musomes of female mice. After a 2-day inhalation of d,l-camphor, cyt. P-450 and the ethylumbelliferone dealkylase were increased by 250 per cent and the NADPH-cyt. P-450 reductase by 350 per cent. The product [NADPH-cyt. P-450 reductase activity × cyt. P450 concentration] was shown to be a suitable reference parameter for the ethylumbelliferone dealkylase activity in the liver musomes during the treatment with four different inducers. The relative dealkylase activity Q was much decreased during inhalation of cyclohexane or d,l-camphor.

$\text{Q =}\text{mU ethylumbelliferone dealkylase}\text{mU NADPH-cty. P-450 reductase × nmoles cty. P-450/mg protein}$

Obviously these two inducers preferably enhanced cyt. P-450 species with a low dealkylase activity. The Q-values were reproducible. Q was increased by 100 per cent during induction of a MC-sensitive mouse strain with 3-methylcholanthrene, but it was only moderately decreased by induction with phenobarbital. Corresponding to this, methylcholanthrene is known to selectively induce a cyt. P-448 with high dealkylase activity whereas phenobarbital is known to change the hydroxylase specificity in the liver musomes not very much.