The effects of actinomycin D and chloramphenicol on the rat preimplantation embryos

Actinomycin D and chloramphenicol, injected in the rat on day 3 or 4 of gestation, induce embryolethality and embryotoxicity. These effects are revealed on day 5 of pregnancy by reduced number of blastocysts and by decrease of mean blastomeres number.     

Decrease of mast cells in regional lymph nodes in response to allogeneic antigens and syngeneic tumor antigens

Summary The absolute number of mast cells in regional lymph nodes decreases on the 5th day after stimulation by allogeneic lymphocytes and semisyngeneic leukaemic cells, despite the enlargement of stimulated lymph nodes. It is postulated that the reaction of lymphatic mast cells could be a sensitive test for tissue incompatibility, and probably also for the presence of tumor associated antigens.     

Zum phototaktischen Laufverhalten junger Honigbienen (Apis mellifica L.)

Summary The number of phototactic runs towards low light intensities of young bees (Apis mellifica L.) depends on their age. On the 1st day there is almost no response. After the 4th day a light intensity as low as 0.1 Lux induces a phototactic run. This increase of response coincides with the performance of the 1st exercise flight.     

Adrenalectomy,ovarian HCG-binding and the onset of female puberty in the rat

Summary The delay of puberty onset in female rats adrenalectomized before the 25th day of age is due neither to changes in the number of ovarian HCG-receptors nor to an altered hormone affinity of these receptors. It is assumed that glucocorticoids act on an intracellular level, in the ovarian cells, possibly by alterations of cyclic AMP-dependent phosphodiesterase activity.This work was supported in part by the Deutsche Forschungsgemeinschaft (SFB 46). Purified HCG was a gift of Schering AG, Berlin-West. We thank Mrs Margarete Lindig for assistance and Mrs Ursula Frigewski for secretarial help.     

Cellular damage and recovery of the early developing mouse eye following low dose irradiation. I. X-rays on day 8 of gestation

Summary The eye region of mouse embryos, irradiated with 90 rad X-rays on day 8 of gestation, was examined 24 h later for cellular damage. Besides the overall developmental retardation, the radiation insult decreased the proliferation rate and altered the mitotic phase ratio. Due to the limited extension of necrotic zones, a reduced number of dead cells was found in the irradiated optic vesicles.Supported by the Swiss National Foundation for Scientific Research. The technical assistance of Mrs E. Frei is gratefully acknowledged.     

Serum prolactin levels and maintenance of progeny by prenatally-stressed female offspring.

Prenatal stress significantly reduced the number of progeny born to 47% of the female offspring and significantly increased the incidence of low birthweight young. None of these litters survived by the tenth postpartum day when serum prolactin levels were significantly reduced. Upon autopsy, these females had twice as many uterine implantation sites than the number of fetuses they bore, suggesting that a) the reduced postpartum serum prolactin most likely was the cause rather than the effect of the neonatal mortality and b) major hormonal deficiencies (possibly gonadotropic-related) were present even before giving birth.     

Effects in man of a total adrenal cortical extract on delayed immunity and lymphocyte sub-populations]

After a 10 day treatment with total adreno-cortical extract, administered to 11 subjects, the following results were obtained: increase of delayed cutaneous responses to various antigens, increase in the number of null lymphocytes, decrease in the number of B lymphocytes. These changes did not occur in 16 control patients who were not treated.     

Serum prolactin levels and maintenance of progeny by prenatally-stressed female offspring

Summary Prenatal stress significantly reduced the number of progeny born to 47% of the female offspring and significantly increased the incidence of low birthweight young. None of these litters survived by the tenth postpartum day when serum prolactin levels were significantly reduced. Upon autopsy, these females had twice as many uterine implantation sites than the number of fetuses they bore, suggesting that a) the reduced postpartum serum prolactin most likely was the cause rather than the effect of the neonatal mortality and b) major hormonal deficiencies (possibly gonadotropic-related) were present even before giving birth.     

Effect of a steroid contraceptive, "Enidrel" on the pre- and postnatal development of rats

To determine the long-term effects of prolonged and intensive treatment with an anticonceptive steroid, 60 female Wistar rats were given 1 mg/kg/day Enidrel (norethynodrel plus ethinyl estradiol 3-methyl-ether) by gastric sound for 60 days. The animals were divided into 2 groups and were placed with males for 10 days. Group 1 continued to recieve Enidrel through mating to the 15th day of gestation; Group 2 received no further treatment. General behavior and weight of the animals was unchanged when compared with controls. There were profound disturbances in the estrous cycle, but couplings and number of impregnations were normal in both groups. Most of the females in Group 1 aborted normal fetuses between Gestation Days 8 and 15; those in Groups 2 continued to term. Group 1 animals were remated and siblings of the 1st generation were crossed. The animals were fertile and the ne onates developed normally. It is concluded that Enidrel had no effect on morphogenesis and no masculinization effect on the hypophyso-hypothalamic system, as evidenced by the normal sexual behavior and fertility of the females.     

Malarial parasites complete sporogony in axenic mosquitoes

To obtain sporogonic stages of malaria free from microbial contaminants for in vitro studies, Anopheles stephensi were reared under sterile conditions using a mosquito cell line as larval food. The adult females, kept in sterile humidified containers and allowed to engorge on parasitemic hamsters, supported the sporogonic development of the rodent malarial parasite Plasmodium berghei. In 10 experiments, the proportion of infected mosquitoes varied from 0 to 92%, and the geometric mean number of oocysts per female mosquito from 2.5 to 58.6, with a range of 1 to 548. The average number of salivary gland sporozoites per infected mosquito was determined by direct sporozoite counts in the pooled homogenate of the thoraces of all female mosquitoes. In five experiments, it varied from 2.7 X 10(3) to 9.0 X 10(3). The sterile sporozoites, harvested on day 19 or 20 after the infective blood meal, were as infective for rodents as nonsterile ones.     

参附动员内皮祖细胞改善肝移植大鼠缺血再灌注损伤

目的 观察参附注射液对发生肝移植缺血再灌注损伤(IRI)的大鼠外周血中内源性内皮祖细胞(EPCs)的作用以及此作用对其肝脏功能的影响.方法 100只雌性SD大鼠随机分为3组:原位肝移植(0LT)+参附(SF)组,OLT对照组,假手术组.3组均于术后第1、4、7天取血液标本流式细胞术检测外周血内皮祖细胞数量及生化分析仪检测肝功能,观察胆汁分泌量,并取肝组织标本进行HE染色形态学观察肝脏损伤.结果 OLT+ SF组外周血中的EPCs在术后1天开始增加,第4天达到高峰并持续至第7天;并且在3个时间点上,OLT+ SF组的外周血EPCs数量较其它两组明显增加,具有统计学意义(p ＜0.01);OLT+ SF组在用药后IRI有所改善,较对照组有统计学差异(p＜0.05).结论 参附注射液能显著动员大鼠骨髓中的内源性EPCs进入外周血,修复损伤的肝血窦,改善微循环,进而改善肝移植术后的缺血再灌注损伤.     

Cell kinetic studies in the epidermis of the mouse. I. Changes in labeling index with time after tritiated thymidine administration

The changes in the labeling index (LI) with time after a single injection of tritiated thymidine (3HTdR) at each of 4 different times of the day have been studied. Slight differences occur in the shape of these LI curves, (e.g. in the timing of the peaks) depending on the time of day when the initial injection was given. Thus, the time of day influences not only the number of cells in DNA synthesis but also determines the subsequent behavior of the labeled cells. The curves show 3 distinct peaks from which estimates of the cell cycle time can be made. The technique permits the cell cycle time to be estimated. From the data as a whole a minimum cell cycle time of 90 h for basal cells in the epidermis on the back of a mouse is obtained. The technique also provides estimates for the duration of S + G2 + M which varies depending on the time of day that the label is given. The LI curves can best be understood if the basal layer is assumed to contain 2 cell populations with differing cell cycle times; one having a long cell cycle (about 180 h) but short S-phase and containing the stem cells, the other having a short cell cycle (about 90 h) and a long S-phase duration and consisting of transit cells.     

Bacterial endotoxin and impaired fetal development

Summary Small doses ofE. coli endotoxin given to pregnant mice on the 13th day of pregnancy caused only a mild maternal illness but induced resorption of approximately half the number of fetuses in each mouse. The remaining live fetuses developed normally and showed no evidence of retarded growth or malformations. The weights of their placentas and maternal spleens increased significantly. Endotoxin given on the 6th day of pregnancy caused a small reduction in fetal weights.Acknowledgments. I am indebted to Mrs.Heather Sandison for technical assistance and to Mr.M. J. R. Healy for statistical examination of the results. Dr.A. B. G. Lansdown kindly advized on the interpretation of histological findings.     

A simple method for counting nuclei in the preimplantation mouse embryo

An easy and rapid method of counting the number of cells in the preimplantation mouse embryo is described. The procedure increases the speed with which large numbers of embryos can be processed using a simple squash technique. Cell numbers are determined by exposing the embryos to the fluorescent DNA-binding dye, Hoechst 33258, removing the zona pellucida and simply squashing the embryo and counting the number of fluorescent nuclei. An increase in fluorescent intensity and maintenance of nuclear conformation of the squashed preparations are greatly improved by the use of the non-ionic detergent Triton X-100. Viability of dye-treated fertilized one-cell and blastocyst stage embryos is maintained at least up to day 13 of pregnancy following transfer of the embryos to the uteri of pseudopregnant recipients. Additional uses for this staining technique are discussed.     

Abortive effect of autologous anti-alpha-fetoprotein antibodies in the rat]

Female Commentry Rats 80--85 days old, were immunized by 5 intramuscular injections of Mouse alphafetoprotein (AFP) and then mated. After fertilization a supplementary injections was administered. The animals were bled at different times and killed immediately after the last bleeding on the 19 or 20th day of gestation. Titers of AFP and of autologous anti-AFP antibodies in the maternal blood were determined as well as the AFP concentration in the pooled amniotic fluids from live embryos of each litter. Compared to non-immunized control series, the total of live and dead embryos per litter in animals immunized with Mouse AFP showed no difference. However, the number of live embryos was on the average 50% lower than that in the control series. The serum titers of AFP and of antibodies to autologous AFP in immunized pregnant Rats bearing dead embryos decreased concomitantly with the number of live embryos. The results reported herein demonstrate that the presence of anti-autologous AFP antibodies in pregnant Rats correlates with the interruption of development in a significant proportions of embryos. This suggests that certain spontaneous abortions in the Rat and perhaps in other mammals can be explained by the rupture of immunological tolerance to autologous AFP.     

Circadian rhythms and their mechanisms

Summary Recent work concerning the number, site(s) and means of adjustment to the 24-h day of internal clocks is reviewed. Work on humans is considered wherever possible though much of the work involving ablation and in vitro techniques necessarily involves other species, particularly rodents. It is concluded that, though recent advances have been impressive and present techniques appear likely to continue to produce results and stimulate discussion, more attention should be directed to considering the circadian system as a whole rather than as an assemblage of individual components.     

Circadian rhythms and their mechanisms

Recent work concerning the number, site(s) and means of adjustment to the 24-h day of internal clocks is reviewed. Work on humans is considered wherever possible though much of the work involving ablation and in vitro techniques necessarily involves other species, particularly rodents. It is concluded that, though recent advances have been impressive and present techniques appear likely to continue to produce results and stimulate discussion, more attention should be directed to considering the circadian system as a whole rather than as an assemblage of individual components.     

Circadian variation of the streptozotocin-diabetogenic effect in mice

Summary Streptozotocin was injected in normal mice every 4h, during the day. Greatest number of diabetic animals were obtained at 16.00 h (95%) and lowest at 08.00 h (50%). Magnitude of hyperglycemia also showed similar distribution. This effect might be considered when planning its use for both experimental and clinical purposes.This work was done with funds provided by Conicet, Secyt and Cediquifa.Thanks are due to Dr W. E. Dulin for kindly provision of SZ and Mrs E. E. Gagliardino for technical assistance.     

Circadian variation of the streptozotocin-diabetogenic effect in mice.

Streptozotocin was injected in normal mice every 4 h, during the day. Greatest number of diabetic animals were obtained at 16.00 h (95%) and lowest at 08.00 h (50%). Magnitude of hyperglycemia also showed similar distribution. This effect might be considered when planning its use for both experimental and clinical purposes.     

Malarial parasites complete sporogony in axenic mosquitoes

Summary To obtain sporogonic stages of malaria free from microbial contaminants for in vitro studies,Anopheles stephensi were reared under sterile conditions using a mosquito cell line as larval food. The adult females, kept in sterile humidified containers and allowed to engorge on parasitemic hamsters, supported the sporogonic development of the rodent malarial parasitePlasmodium berghei. In 10 experiments, the proportion of infected mosquitoes varied from 0 to 92%, and the geometric mean number of oocysts per female mosquito from 2.5 to 58,6, with a range of 1 to 548. The average number of salivary gland sporozoites per infected mosquito was determined by direct sporozoite counts in the pooled homogenate of the thoraces of all female mosquitoes. In five experiments, it varied from 2.7×10³ to 9.0×10³. The sterile sporozoites, harvested on day 19 or 20 after the infective blood meal, were as infective for rodents as nonsterile ones.Supported in part by Public Health Service research grant AI 18345 from the National Institute of Allergy and Infectious Diseases, by a grant from the Agency of International Development DSPE-5542-G-SS-3042-00, and by a Charles and Johanna Busch award.