Teratogenic effects of cyproterone acetate and medroxyprogesterone treatment during the pre- and postimplantation period of mouse embryos. I

Pregnant mice were treated with a single subcutaneous injection of either cyproterone acetate (CA) or medroxyprogesterone acetate (MPA). In the first experiment the animals received 5-900 mg/kg of the hormone before implantation (day 2 of pregnancy). CA treatment on day 2 caused a dose-dependent decrease in fetal weight and a significant dose-dependent increase in the rates of cleft palate and urinary tract abnormalities. Exencephaly and heart abnormalities were also significantly more frequent, but this increase was not dose-dependent. MPA treatment on day 2 was followed by sporadic increases in dead and resorbed fetuses, a decrease in fetal weight and an increase in the rates of cleft palate, and malformed or abnormally developed fetuses. None of these effects, however, was dose-dependent. In the second experiment the mice were given one single injection (30 mg/kg) of CA or MPA on any one of days 1-12 of gestation. Treatment with CA on one day between days 1 and 12 revealed that the specific sensitivity for abnormalities of the urinary tract was on days 5 and 6, for the respiratory tract on days 8 and 9, and for cleft palate on days 10 and 11. Treatment with MPA on one day between days 1 and 12 only revealed a high rate of respiratory and urinary tract abnormalities on day 9. After treatment with MPA cleft palate was again significantly more frequent in all treated groups, however, days of peak sensitivity were not detected. The long half-life of CA (60 hours) explains the teratogenic effect of high doses of this progestin after treatment on day 2 and also the pattern of abnormal development found after treatment with a single dose of CA on one of the days between day 1 and day 12.     

Effect of testosterone on the rate of total protein synthesis in the reproductive tract of rabbit embryos in vitro

The total protein synthesis rate in the reproductive tract and muscles of rabbit fetuses was evaluated at the 18th-22nd day of development by the intensity of 3H-leucine incorporation in experiments in vitro. Testosterone increased the total protein synthesis rate in the tissues of the reproductive tract at all the developmental stages under study. The highest rate of protein synthesis was recorded on the 18th day of development.     

Light-induced acceleration of retina development in a mouth-brooding teleost.

Rearing animals in the dark had been shown to be either without effect on the development of the retina or to result in a reduction or a delay of retinal maturation. In the present study, the influence of light on a retina which normally develops under conditions of very dim light has been investigated. When 3-day-old embryos of the mouth-brooding teleost Tilapia leucosticta are placed into a continuously lighted environment, from day 6 on, optic tract diameter and inner plexiform layer thickness increase up to day 10 or 12. In the dark-reared retina, this increase occurs only after day 10. Similarly, synaptic junctions of the inner plexiform layer appear at about day 6 in the light-reared retina and increase continuously on following days, whereas in the retina of embryos reared in darkness, they appear at day 7 and do not increase essentially before day 11. These and other data suggest that continuous light induces a precocious growth of retinal structures. The first differences between light- and dark-reared retinae appear synchronously with the beginning of receptor cell development and prior to the first synaptic junctions. A non-neurally mediated effect of light on the retinal ganglion cells is consequently assumed.     

The male genital tract and the nipples of male and female offspring of rats given the non-steroidal antiandrogens DIMP and Sch 13521, during pregnancy.

Male and female offspring of rats given antiandrogens, the steroidal BOMT or the non steroids DIMP or Sch 13521, daily during the last third of pregnancy were studied. Detailed examinations were made of the genital tract of male, and of the nipples of male and female offspring. A) Male offspring. 1) Genital tract of newborn and 31-91 day old males : Modifications of the development of accessory sexual tissues were found in all treatment groups. As indicated by the severity of deviations from normal (morphology and weight of sex accessories), the antiandrogenic effect of the preparations, in the doses given to the mother rats, increased from BOMT (50 or 75 mg/day) via Sch 13521 (30 mg/day) and DIMP (50 or 60 mg/day) to Sch 13521 (60 mg/day). 2) Nipples of 10-60 day old males : Whole mount preparations were made unilaterally of the row of 6 mammary glands with nipples. The number of intact and abnormal nipples, respectively, was recorded. The relation between intact and abnormal nipples served as indicator of the efficiency of the antiandrogenic substances studied. The result showed that the antiandrogenic effect increased from BOMT to Sch 13521, 60 mg, in the same order as that arrived at from studies of the genital tract. The combined results obtained from the male offspring indicated that the tissues of the genital region, the growth and differentiation of which was most readily impaired by antiandrogens, were the same as those known from other work to be stimulated most easily in female rat fetuses by testosterone. B) Female offspring. Nipples of 31-60 day old females were judged from whole mount preparations and recorded as in the males. The nipples of adult virginal females were examined macroscopically. The same procedure was applied to lactating females, but the results were controlled in consecutive lactational periods and at autopsy. The 3 groups of females showed uniformly that 1) offspring of rats given BOMT during pregnancy had many (about 50 per cent) malformed nipples and 2) the treatment of mother rats with DIMP or Sch 13521 did not influence the development of nipples in female offspring. The result was assumed to be due to an androgenic effect of the steroidal antiandrogen, BOMT, on the nipple anlage.     

Quantitative analysis of postnatal myelin sheath development in the dorsal funiculus of rat

Postnatal development of myelin sheaths in the dorsal funiculus of rats has been studied qualitatively by light microscopy and morphometry. A distinction is made between Goll's tract and Burdach's tract, and, furthermore, inside Goll's tract the cervical, thoracic and lumbar areas are compared. The induction of myelinization is influenced by a critical range of axon thicknesses. Between the 15th and 20th days of postnatal maturation there is a minimal growth reaction in the dorsal funiculus, but after the 20th day up to the 120th day extensive growth of the myelin sheath can be seen. Burdach's tract shows earlier and faster development of the myelin sheath than Goll's tract cervically, which leads to the conclusion that epicritical sensitivity matures earlier in the upper extremity. Concerning Goll's tract in the lumbar area of the dorsal funiculus, faster maturation than in the thoracic and cervical areas can be seen.     

Perinatal development of mammillotegmental connections in rats

Development of direct axonal connections of the hypothalamic mammillary bodies with ventral and dorsal tegmental nuclei of Gudden was studied on fixed rat brains from day 14 of embryonic development until day 10 of postnatal development using the method of diffusion of the lipophilic fluorescent carbocyanine tracer 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate along the neuronal membranes. The tracer was inserted into the mammillary bodies or into the tegmentum and, after incubation in a fixative, fluorescent nerve cells and nerve fibers were visualized in the brain tissue. The mammillotegmental tract was found to start developing earlier than other projection systems of the mammillary bodies. On days 14–15 of embryonic development, it was visualized as a bundle of axons running from the mammillary bodies caudally to the midbrain. A group of neurons in the midbrain tegmentum and their axons going to the mammillary bodies via the mammillary peduncle were first visualized on day 19 of embryonic development. The mammillotegmental tract and mammillary peduncle developed progressively from the moment of birth. Ventral and dorsal tegmental nuclei were formed in the midbrain by day 10 of the postnatal development. Thus, the formation of reciprocal connections of the mammillary bodies with midbrain tegmental nuclei was first described during perinatal development in rats.     

Perinatal development of mammillotegmental connections in rats

Development of direct axonal connections of the hypothalamic mammillary bodies with ventral and dorsal tegmental nuclei of Gudden was studied on fixed rat brains from day 14 of embryonic development until day 10 of postnatal development using the method of diffusion of the lipophilic fluorescent carbocyanine tracer 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate along the neuronal membranes. The tracer was inserted into the mammillary bodies or into the tegmentum and after incubation in a fixative fluorescent nerve cells and nerve fibers were visualized in the brain tissue. The mammillotegmental tract was found to start developing earlier than other conducting systems of the mammillary bodies. On days 14-15 of embryonic development, it was visualized as a bundle of axons running from the mammillary bodies caudally to the midbrain. A group of neurons in the midbrain tegmentum and their axons going to the mammillary bodies via the mammillary peduncle were first visualized on day 19 of embryonic development. The mammillotegmental tract and mammillary peduncle developed progressively from the moment of birth. Ventral and dorsal tegmental nuclei were formed in the midbrain by day 10 of the postnatal development. Thus, the formation of reciprocal connections of the mammillary bodies with midbrain tegmental nuclei was first described during perinatal development in rats.     

中国大鲵胃肠道胚后发育的解剖学与组织学观察

为了探讨中国大鲵(Andrias davidianus)胃肠道形成、分化及发育的基本特征,采用解剖学和组织学方法对其胃肠道胚后发育的形态结构变化进行了观察.结果表明,出膜第7天时的大鲵,胃肠道尚未分化,为一直管;出膜第21天时,已有胃和肠的分化;出膜第35天时,分化出了胃、小肠和大肠.出膜第7天时,胃肠道壁仅由黏膜上皮...     

The development of the peripheral autonomic nervous system in relation to the gastro-intestinal tract

In this study the development of vagus nerves and the development of sympathetic nerves related to the development of the upper gastro-intestinal tract was studied in the rat from 12.5 days p.c. until birth by means of enzyme histochemical methods applied to sections and toto preparations. A striking time relation between the ingrowth of the vagus nerves as well as the sympathetic nerves and the appearance of acetylcholinesterase (AChE)-positive cells in the wall of the upper gastro-intestinal tract is established. The maturation of the upper enteric ganglion cells is dependent on the presence of a vagal influence. The vagal ingrowth of the stomach starts at about day 12.5 p.c. In AChE toto preparations it is established that the basic distribution pattern as described in the adult rat is complete at day 15 p.c. However, in contrast with the adult state, gastric branches can be traced up to the pylorus and the greater curvature until day 18 p.c. During the 18th day p.c. there is a tremendous increase in the surface area of the stomach. This increase in surface area of the gastric wall and relative decrease in vagal outgrowth leads to the adult configuration of vagal ramifications in relation to the wall of the stomach which can already be observed on the 19th day p.c.     

Effect of graded levels of rapeseed oil in isonitrogenous diets on the development of the gastrointestinal tract,and utilisation of protein,fat and energy in broiler chickens

The effect of feeding 0, 4, 8 and 16% rapeseed oil from 12–42 days of age was studied in broiler chickens on performance, digestibility of nutrients, and development of gastrointestinal tract, protein and energy metabolism. Thirty six female chickens (Ross 208) with initial body weight average 246 g were allocated to the four groups and kept pair-wise in metabolism cages. The chickens were fed similar amounts of metabolisable energy (ME) per day and similar amounts of essential amino acids relative to ME by adjusting with crystalline amino acids. The chickens were subjected to four balance periods each of five days with two 24 h measurements of gas exchange in two open-air-circuit respiration chambers inserted on the second and third day of each period. The addition of rapeseed oil increased the amount of gutfill indicating a reduced rate of passage and causing a hypertrophy of the gastrointestinal tract. There was a positive effect on feed utilisation as well as on digestibility especially of dietary fat together with higher utilisation of protein with addition of rapeseed oil. The partial fat digestibility of rapeseed oil estimated by regression was 91.1% and the partial metabolisability (ME/GE) of the rapeseed oil was estimated to 85% yielding an apparent metabolisable energy value of 34.30 MJ/kg.     

Effect of graded levels of rapeseed oil in isonitrogenous diets on the development of the gastrointestinal tract, and utilisation of protein, fat and energy in broiler chickens

The effect of feeding 0, 4, 8 and 16% rapeseed oil from 12-42 days of age was studied in broiler chickens on performance, digestibility of nutrients, and development of gastrointestinal tract, protein and energy metabolism. Thirty six female chickens (Ross 208) with initial body weight average 246 g were allocated to the four groups and kept pair-wise in metabolism cages. The chickens were fed similar amounts of metabolisable energy (ME) per day and similar amounts of essential amino acids relative to ME by adjusting with crystalline amino acids. The chickens were subjected to four balance periods each of five days with two 24 h measurements of gas exchange in two open-air-circuit respiration chambers inserted on the second and third day of each period. The addition of rapeseed oil increased the amount of gutfill indicating a reduced rate of passage and causing a hypertrophy of the gastrointestinal tract. There was a positive effect on feed utilisation as well as on digestibility especially of dietary fat together with higher utilisation of protein with addition of rapeseed oil. The partial fat digestibility of rapeseed oil estimated by regression was 91.1% and the partial metabolisability (ME/GE) of the rapeseed oil was estimated to 85% yielding an apparent metabolisable energy value of 34.30 MJ/kg.     

头孢哌酮钠舒巴坦钠治疗下呼吸道感染的临床疗效观察

目的:观察注射用头孢哌酮钠舒巴坦钠治疗下呼吸道感染的有效性和安全性;方法:80例下呼吸道感染患者随机分为治疗组和对照组,治疗组静脉滴注头孢哌酮钠舒巴坦钠2.0g,q12h,疗程7天,对照组静滴注射用头孢曲松钠2.0g,q12h,疗程7天;结果:治疗组和对照组治疗下呼吸道感染的有效率分别为95%和92.5%,细菌清除率分别为94%和95.7%,不良反应发生率为7.5%和5%,两组比较无统计学差异(p>0.05)。结论:头孢哌酮钠舒巴坦钠治疗下呼吸道感染疗效高,安全性好。     

Effect of substitution of oat hulls for traditional fiber source on digestion and performance of fattening rabbits

The objective of this study was to evaluate the use of oat hulls (OH) to substitute traditional fiber (a mixture of rice hulls and mugwort (RHM) leaf) in the diets of fattening rabbits by examining on its effect on the growth performance, coefficient of total tract apparent digestibility (CTTAD) of nutrients, gastrointestinal tract development, cecum fermentation and carcass traits. A total of 160 mixed sex Hyla commercial meat rabbits (40/treatment) were used to study the effects of including OH in the diet from 30 to 80 days of age. A control diet based on RHM and containing 175.2 g crude fiber and 169.7 g CP/kg was included. Growth performance and CTTAD of nutrients were recorded from day 35 to day 80 and day 74 to day 80, respectively, whereas gastrointestinal tract development, cecum fermentation and carcass traits were determined at day 80. Increasing concentrations of OH in the diet increased average daily feed intake (P=0.0018), but have no effects on average daily gain and feed conversion ratio (P>0.05). Moreover, the 150 g/kg OH diet decreased the relative weight of full cecum and cecal content (P<0.05), but did not affect other gastrointestinal organs. The CTTAD of NDF and gross energy decreased with the inclusion of OH (P<0.05). No effects of CTTAD of ADF, ADL, dry matter, CP and ether extract were observed (P>0.05). The concentrations of total volatile fatty acid, acetic and butyric acids were greater in rabbits fed the lower levels of OH (0 to 100 g/kg) compared with higher rate (150 g/kg; P<0.05). However, the proportions of acetic, propionic and butyric acids were not affected by treatments (P>0.05). Furthermore, no significant effect on the ratios of acetic/(propionic+butyric) was observed (P>0.05). Hot carcass weight, pH (45 min, 24 h), lightness, redness, yellowness, 24-h drip loss of longissimus lumborum muscles were not affected by diet OH (P>0.05). However, dressing out percentage increased with higher (150 g/kg) inclusion of OH. It is concluded that OH can be included in rabbit diets at levels up to 100 g/kg, but negative effect on digestion and performance were observed with the increasing of OH (150 g/kg).     

Development and sexual maturation of Taenia crassiceps (Cestoda) in the golden hamster

The development of cysticerci of Taenia crassiceps to mature tapeworms in the intestinal tract of cortisone-treated and untreated golden hamsters is described. The development of the worms in untreated hamsters is as follows. Maturation and branching of the uterus and the presence of ova in the uterus were observed on day 15 postinfection (PI). By day 21 PI, fertilization had taken place, as evidenced by the presence of sperm in the seminal receptacle. On day 28 PI, shelled eggs were observed in feces. The rate of development of the worms in cortisone-treated hamsters was similar to that observed in untreated hamsters. More worm recovery and a longer period of worm survival were seen in the cortisone-treated than in the untreated hamsters. Thus, both cortisone-treated and untreated golden hamsters can produce normal gravid individuals of T. crassiceps.     

Effects of antitussive drugs under normal and pathological conditions

The antitussive effect codeine and 1-propoxyphene have been studied in non-anaesthetized healthy cats and cats with respiratory tract inflammation elicited by undiluted croton oil. The drugs were administered intraperitoneally in doses of 10 and 20 mg/kg body weight. The antitussive effect was studied on the 4th day, after inflammation had set in. Cough induced in nonanaesthetized cats by mechanical irritation of the laryngopharyngeal and tracheobronchial areas was evaluated by changes of the lateral tracheal pressure. Experimentally induced inflammatory changes of the respiratory tract due to the antitussive activity of 1-porpoxyphene were significantly reduced, but that of codeine had not changed at all.     

Critical window of male reproductive tract development in rats following gestational exposure to di-n-butyl phthalate

BACKGROUND: Gestational exposure to di-n-butyl phthalate (DBP), a ubiquitous environmental contaminant, has been shown to interfere with the development of the male reproductive tract by acting as an antiandrogen. This study was conducted to identify the critical days for the abnormal development of the male reproductive tract, specifically the testis and epididymis. METHODS: Timed-pregnant Sprague-Dawley rats were dosed with DBP at 500 mg/kg/day on gestation day (GD) 14 and 15, 15 and 16, 16 and 17, 17 and 18, 18 and 19, or 19 and 20 (GD 0=plug day). Anogenital distance (AGD) was measured on postnatal day (PND) 1 and 13, while areloa number was recorded on PND 13 only. After weaning, males were allowed to mature to PND 90 at which time they were necropsied. Areloa number and AGD were recorded and testes, epididymides, seminal vesicles, prostate gland, kidneys, and liver weighed. Blood serum was collected and assayed for total testosterone concentration. RESULTS: There were no observable effects on litter size, sex ratio, serum testosterone concentration, or mortality of pups. Statistically significant permanent reductions in AGD were seen in males exposed prenatally to DBP on GD 15 and 16 or GD 18 and 19. On PND 13, areola were present in males exposed to DBP on GD 15 and 16, 16 and 17, 17 and 18, and 19 and 20. However, permanent retention occurred only in males after DBP exposure on GD 16 and 17. Exposure to DBP on only GD 17 and 18 elicited a reduction in epididymal weights; while exposure on only GD 16 and 17 caused a significant increase in the weights of the testes due to edema. In this study, epididymal and testicular malformations were most prevalent after exposure to DBP on any gestational day. Epididymal malformations, characterized by agenesis of various regions and small or flaccid testes were significantly increased in DBP-exposed males only on GD 16 and 17. CONCLUSIONS: These findings suggest that 2-day DBP exposure is highly detrimental to the developing reproductive tract of the male fetus and the critical window for abnormal development is GD 16-18.     

Chicken keratin-19: Cloning of cDNA and analysis of expression in the chicken embryonic gut

From many recent studies, it has been argued that keratins (cytokeratins) play important roles in the morphogenesis and differentiation of organ development. To learn the role of keratin in digestive tract development, a cDNA of the chicken homolog of keratin-19 ( GK-19 ) was cloned and its expression pattern was analyzed in the digestive tract of chicken embryos. The GK-19 full-length sequence was approximately 1.6 kb and showed more than 80% similarity to human and mouse keratin-19. The result of in situ hybridization with the proventriculus (glandular stomach) of different developmental stages showed that GK-19 expression disappeared specifically in the glandular epithelium from day 6 to day 9 of incubation. Furthermore, GK-19 was localized in the notochord, floor plate, anterior lobe of the pituitary gland and mesonephros. These results suggest the possibility that GK-19 may have multiple roles in organogenesis during embryogenesis.     

Cross-fostering of voles demonstrates in utero effect of photoperiod

Postweaning body growth and reproductive tract weight of montane voles raised from birth in 14 h light/day are modulated by the photoperiod to which the voles' mothers were exposed while pregnant. This effect could result from factors acting in utero or during lactation, as a result of a change in photoperiod experienced by the mother on the day she gave birth. To distinguish between these hypotheses, male voles exposed to short or long photoperiods during gestation were raised by foster mothers that had been exposed to different photoperiods while pregnant. The differences in body weight, total length, and reproductive tract weight between voles at 74 days of age can be attributed to factors acting in utero. The effects of the gestational photoperiod are not manifested in the patterns of growth until after weaning.     

Respiratory Disease in Young Adults: Influence of Early Childhood Lower Respiratory Tract Illness,Social Class,Air Pollution,and Smoking

The prevalence of cough during the day or night in winter has been studied in 3,899 20-year-olds. These were members of a cohort born in England, Scotland, and Wales in the last week of March 1946. The prevalence of cough and current smoking habits have been related to events recorded during infancy and childhood—that is, exposure to air pollution, social class of father, and lower respiratory tract illness under 2 years of age. At age 20, of these factors cigarette smoking was found to have the greatest effect on symptom prevalence, followed by a history of a lower respiratory tract illness under 2 years of age. Social class and air pollution had little effect.