Phagocytosis by carp granulocytes; in vivo and in vitro observations

The phagocytic ability of carp (Cyprinus carpio L.) granulocytes was evaluated in vivo and in vitro. In suspensions of head kidney cells, neutrophil granulocytes incorporated both latex beads and coccidian merozoites. In intestinal tissues from carp with a Goussia carpelli infection, all granulocyte cell types (neutrophils and cells of the basophilic-eosinophilic complex) phagocytosed cell detritus and coccidian developmental stages, mainly merozoites.     

3,5,3′,5′-Tetrachlorobiphenyl is a weak oestrogen agonist in vitro and in vivo

Polychlorinated biphenyls (PCBs) are widespread, persistent environmental contaminants of which some congeners can act as endocrine disrupters. Previous work has shown that 3,4,3′,4′-tetrachlorobiphenyl (PCB77) can act as an oestrogen with actions mediated through the oestrogen receptor. Here, oestrogenic actions have been assessed for two further tetrachlorobiphenyl isomers. Assays of oestrogenic action have involved (1) ligand regulation of oestrogen-sensitive gene expression; (2) ligand regulation of cell growth in oestrogen-dependent human breast cancer cell lines MCF7 McGrath and ZR-75-1; and (3) ligand activity in the immature mouse uterine weight bioassay in vivo. These results demonstrate that 3,5,3′,5′-tetrachlorobiphenyl (PCB 80) can be considered to be a weak oestrogen agonist, but the 2,5,2′,5′-congener (PCB 52) revealed no oestrogenic properties in any of these assays. Implications of these results are discussed in relation to structure-activity predictions for environmental oestogens.     

Experimental cryosurgery investigations in vivo

Cryosurgery is the use of freezing temperatures to elicit an ablative response in a targeted tissue. This review provides a global overview of experimentation in vivo which has been the basis of advancement of this widely applied therapeutic option. The cellular and tissue-related events that underlie the mechanisms of destruction, including direct cell injury (cryolysis), vascular stasis, apoptosis and necrosis, are described and are related to the optimal methods of technique of freezing to achieve efficacious therapy. In vivo experiments with major organs, including wound healing, the putative immunological response following thawing, and the use of cryoadjunctive strategies to enhance cancer cell sensitivity to freezing, are described.     

Novel in vitro and in vivo inhibitors of prolyl endopeptidase

Inhibition of prolyl endopeptidase by Z-cyclohexyl prolinal and Z-indolinyl prolinal occurs with slow, tight binding inhibition and K_i values of 2 – 3 nM. In vivo enzyme inhibition is also observed with a half time for recovery of enzyme activity of 3 – 4 h.Inhibition of prolyl endopeptidase by Z-cyclohexyl prolinal and Z-indolinyl prolinal occurs with slow, tight binding inhibition and K_i values of 2 – 3 nM. In vivo enzyme inhibition is also observed with a half time for recovery of enzyme activity of 3 – 4 h.     

Gastroprotective effects of ‘Amla’ Emblica officinalis on in vivo test models in rats

An ethanol extract of 'Amla' Emblica officinalis Gaertn. was examined for its antisecretory and antiulcer activities employing different experimental models in rats, including pylorus ligation Shay rats, indomethacin, hypothermic restraint stress-induced gastric ulcer and necrotizing agents (80% ethanol, 0.2 M NaOH and 25% NaCl). Oral administration of Amla extract at doses 250 mg/kg and 500 mg/kg significantly inhibited the development of gastric lesions in all test models used. It also caused significant decrease of the pyloric-ligation induced basal gastric secretion, titratable acidity and gastric mucosal injury. Besides, Amla extract offered protection against ethanol-induced depletion of stomach wall mucus and reduction in nonprotein sulfhydryl concentration. Histopathological analyses are in good agreement with pharmacological and biochemical findings. The results indicate that Amla extract possesses antisecretory, antiulcer, and cytoprotective properties.     

A study of chlorophyll b in vivo

1. The absorption spectrum of chlorophyll b in vivo at 77°K is presented as the difference spectrum between preparations of spinach and chlorophyll b-free Vischeria stellata chloroplasts.

2. A shoulder on this spectrum around 662 nm is due to a component different from chlorophyll b. This component may well be identical with the chlorophyll a form, chlorophyll a (665).

3. The 77°K chlorophyll b absorption spectra in the nonfractionated photosyn-thetic pigment apparatus and in fractions mainly representing Photosystems 1 or 2 are not significantly different.

4. The aerobic irreversible photobleaching of chlorophyll b was studied in the intact pigment complex as well as in fractions mainly consisting of Photosystem 1 or 2. A two-step photobleaching was observed in all cases. The time-course of this bleaching was not significantly different for chlorophyll b in both fractions.

5. These results do not indicate that more than a single chlorophyll b complex occurs in vivo.     

Dietary phytoestrogens and cancer: in vitro and in vivo studies

Thirty postmenopausal women (11 omnivores, 10 vegetarians and 9 apparently healthy women with surgically removed breast cancer) were investigated with regard to the association of their urinary excretion of estrogens, lignans and isoflavonoids (all diphenols) with plasma sex hormone binding globulin (SHBG). A statistically significant positive correlation between urinary total diphenol excretion and plasma SHBG was found which remained statistically significant after elimination of the confounding effect of body mass determined by body mass index (BMI). Furthermore we found a statistically significant negative correlation between plasma SHBG and urinary excretion of 16α-hydroxyestrone and estriol which also remained significant after eliminating the effect of BMI. Furthermore we observed that enterolactone (Enl) stimulates the synthesis of SHBG by HepG2 liver cancer cells in culture acting synergistically with estradiol and at physiological concentrations. Enl was rapidly conjugated by the liver cells, mainly to its monosulfate. Several lignans and the isoflavonoids daidzein and equol were found to compete with estradiol for binding to the rat uterine type II estrogen binding site (the s.c. bioflavonoid receptor). It is suggested that lignans and isoflavonoids may affect uptake and metabolism of sex hormones by participating in the regulation of plasma SHBG levels and in this way influence their biological activity and that they may inhibit cancer cell growth like some flavonoids by competing with estradiol for the type II estrogen binding sites.     

Microrheological characteristics of reticulocyte in vivo

Using the method of phenylhydrazine-induced anemia in rabbits, a mass of new reticulocytes, which synchronously grow, were got in vivo. The measurements of deformation index, orientation index, electrophoresis mobility etc. were performed for more than 72 h in the process of reticulocytes turning into red blood cells in vivo. There were obvious changes in the micro- rheological characteristics of reticulocytes in the course of turning into erythrocytes. The present study is significant in clinic for studying erythrocytes' microrheological characteristics when there are a lot of reticulocytes in blood, and also important in basic theorem for studying reticulocytes microrheological characteristics. It makes up a deficiency in the study on microrheological characteristics of reticulocytes turning into new RBCs from reticulocytes during reticulocytes life span.     

单增李斯特菌胎盘感染的体内外模型研究进展

单核细胞增生李斯特氏菌（Listeria monocytogenes）是重要的食源性致病菌,能引发人类的李斯特菌病,是全球公共卫生问题之一。该菌易感染孕妇,引起胎儿和新生儿的侵袭性李斯特菌病,严重威胁母婴健康。因此,建立有效的单增李斯特菌感染胎盘体内外模型,解析和探究单增李斯特菌经胎盘感染机制,是预防和控制单增李斯特菌感染母婴的关键所在。本文综述了可用于研究单增李斯特菌母婴感染的体内外胎盘模型,总结和讨论了各类模型的优势和局限性;并着重分析了体外三维胎盘屏障模型在单增李斯特菌感染方面的研究进展和未来研究方向。以期为深入解析该菌经胎盘感染的途径、发病机制提供支持,并为预防和控制母婴李斯特菌病提供科学参考。     

体内连续进化——从噬菌体到真核基因组的进化故事（英文）

进化是生物多样性产生和保留的自然进程。通过对编码蛋白质的基因进行有目的地设计和改造,获得性能更优异的蛋白质用于生产生活,是蛋白质工程的目的所在。为了在实验室中通过定向进化的蛋白质工程模拟自然进化的实现过程,研究人员通过在快速增殖的原核生物和简单的真核生物中引入靶向诱变元件,建立了各种体内连续进化系统。本综述介绍了体内连续进化平台的现状,重点关注噬菌体和酵母中人工进化技术的研究进展,并对其在生物技术领域中的成功应用进行了总结,最后简要展望了体内连续进化这一新兴领域的发展方向。     

cAMP levels in proliferating rat mammary epithelial cells in vitro and in vivo

Agents that elevate intracellular cAMP levels are required for growth of many cell types in culture including normal rat mammary epithelial (RME) cells. To determine if the intracellular levels of cAMP that result from stimulation by agents such as cholera toxin (CT) or prostaglandin E-1 (PGE-1) are within the physiological range, cAMP levels were determined in RME cells growing in primary culture and compared to levels measured in freshly isolated mammary epithelium. The results indicate that the cAMP levels of mammary epithelial organoids obtained from 45-day-old virgin rats are 4 to 6 pmol/10⁶ cells. Growth of RME cells in primary culture in the presence of CT results in cAMP levels of approximately 15 to 20 pmol/10⁶ cells early in culture when cells are proliferating rapidly. As cells approach confluence, cAMP concentrations decrease to levels observed in fresh organoids. CT-stimulated cAMP levels appear to be within the range of those found in pregnant mammary epithelium in vivo. Growth of RME cells in medium supplemented with PGE-1 instead of CT results in cAMP levels equivalent to those found in fresh mammary epithelial organoids and under these conditions the growth rate is approximately half that found in CT-stimulated cells. These results indicate cAMP to be a positive regulator of cell growth in vivo at levels that are within the physiological range.     

Relative stability of chlorophyll complexes in vivo

The time course of aerobic photobleaching of various chlorophyll-protein complexes in vivo at high light intensities was studied with isolated Aspidistra elatior chloroplasts.

1. 1. C_a680 bleaching starts with the onset of irradiation and, initially, proceeds linearly with time. Washing the chloroplasts causes a nearly constant increase of the bleaching rate throughout the experiment.

2. 2. C_a670 does not appreciably, if at all, bleach initially; subsequently, bleaching proceeds linearly with time and at a slightly higher rate than that for C_a680. Washing makes C_a670 bleach concomitantly with the onset of illumination, and at a nearly constant rate.

3. 3. Bleaching at 665 nm is likely to start only after a relatively long period of illumination. Washing shows no effects during this period. Once bleaching has started, washing causes its rate to increase.

4. 4. No indication of the occurrence of “short-wave” chlorophyll a forms other than C_a670 and C_a665 was obtained.

5. 5. C_b bleaching starts concomitantly with illumination at a low rate. The rate increases more or less exponentially with time. Washing enhances bleaching in two steps.

6. 6. The importance of the results is discussed.

Bleb formation in granulosa cells of rat pre-ovulatory follicles in vivo and in vitro

To determine if hormone-induced events leading to ovulation an granulosa cell luteinization might be associated with changes in the surface configuration of granulosa cells we have studied the morphology of granulosa cells from the preovulatory follicles both in vivo and in vitro. In vivo, granulosa cells in follicles from rats primed with estradiol and FSH developed bulbous protrusions termed blebs in response to injected hCG. The blebs were restricted to the adluminal granulosa cells which possess the least number of receptors for hCG. When granulosa cells from follicles of rats primed with estradiol and FSH were cultured in vitro, in the absence of serum, approximately 10% of the cells formed blebs. In the presence of 10% rat or fetal calf serum, nearly 90% of the cells formed blebs by 18 hr. Serum-induced bleb formation was prevented by 1 mM dibutyryl cycle-AMP plus 0.5 mM methyl isobutyl xanthine and by cytochalasin B (25 mug/ml), while 0.1 muM colchicine had no effect. Fibronectin at 25 mug/ml increased bleb formation three-fold over control values in serum-free medium. When hCG was included in serum containing medium, the majority of the cells remained smooth without any blebs. Thus, in contrast to its action in vivo, hCG inhibited the formation of blebs in vitro. When the cells incubated in the presence of dbcAMP plus methyl isobutyl xanthine in serum-containing medium, none of the cells formed blebs. One explanation for the seemingly opposite actions of hCG in vivo and in vitro is that hCG might act to alter the permeability of the pre-ovulatory follicles, and thereby allow the admission of serum. The admitted serum component(s) could then induce the formation of blebs on receptor-deficient adluminal cells that did not have elevated cAMP concentrations. The results suggest that fibronectin and/or other serum components, act to induce microfilament-dependent, cAMP-inhibited bleb formation on granulosa cells in vivo and in vitro.