bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of lung surfactant in the metamorphosing bullfrog (Rana catesbeiana)
Authors: Oguchi Atsuko , Mita Masatoshi , Ohkawa Muneyoshi , Kawamura Kosuke , Kikuyama Sakaé
Published: June 2005

In bullfrog (Rana catesbeiana) tadpoles, the lung begins to function at an advanced stage of metamorphosis. As a preliminary step for investigation of the mechanisms involved in lung maturation, pulmonary surfactant was prepared from tadpoles at advanced stages of metamorphosis and its biochemical properties were analyzed. Surfactant phospholipid analysis revealed that the major constituent was phosphatidylcholine (PC), as examined in the animals at late climax (stage 24). Other detectable phospholipids were phosphatidylethanolamine, phosphatidylserine, sphingomyelin, and phosphatidylglycerol, a marker lipid in mammalian surfactant. As in mammals, PC in the surfactant was rich in saturated fatty acids, about 50% of fatty acid moieties being palmitic acid. The content of surfactant PC in the lung increased moderately around mid‐climax and markedly at the end of climax. The effect of antiserum against bullfrog prolactin (PRL) on the pulmonary surfactant was studied in climactic tadpoles. The content of surfactant PC in the lung of the antiserum‐treated larvae was lower than that in the lung of the normal rabbit serum‐injected larvae, whereas the content of PC in the whole lung did not differ between the antiserum‐treated and control groups. The results suggest that synthesis of surfactant in the amphibian lung is enhanced as metamorphosis progresses and that PRL is involved in lung maturation. © 1994 Wiley‐Liss, Inc.
Patterns of temperature‐dependent sex determination in turtles
Authors: Ewert Michael A. , Jackson Dale R. , Nelson Craig E.
Published: June 2005

Among reptiles that show temperature‐dependent sex determination, sex ratios vary across constant incubation temperatures in ways sufficiently predictable to allow classification into patterns. One common pattern shows low temperatures yielding only males and high temperatures yielding only females. Another common pattern has low as well as high temperatures yielding only or mostly females and some intermediate temperatures yielding mostly males. Patterns tend to be associated with the direction of sexual dimorphism in adult size, especially for species with strong dimorphism.

Pivotal temperatures (those yielding 1:1 sex ratios) within the best‐documented species and genera tend to increase with both latitude and longitude across central and southern North America. These geographic trends probably reflect factors that affect nest temperatures (duration of growing season, insolation, and prevailing amounts of shading by vegetation).

Data from a population of the alligator snapping turtle (Macroclemys temminckii) suggest that some embryos are temperature‐independent females because these individuals become females even when they are shifted among male‐producing temperatures during development. These individuals are also more frequent in clutches of small eggs. In this and several other species, no constant incubation temperatures yield more than 75% males. © 1994 Wiley‐Liss, Inc.
Temperature‐dependent sex determination in crocodilians
Authors: Lang Jeffrey W. , Andrews Harry V.
Published: June 2005

Half of the 22 extant crocodilians show evidence of temperature‐dependent sex determination (TSD). We examine evidence for TSD in 11 species by reviewing reports on five and presenting new data for six. The female‐male pattern (FM; females at low temperature, males at high temperature) attributed to Alligator mississippiensis and Caiman crocodilus are here revised to be female‐male‐female (FMF; males at intermediate temperature, females at low and high temperatures). A similar pattern characterizes Crocodylus palustris, C. moreletii, C. siamensis, and Gavialis gangeticus based on new data; published accounts establish a FMF pattern in Crocodylus porosus, C. johnstoni, and C. niloticus. TSD apparently occurs in Paleosuchus trigonatus and Alligator sinensis, but patterns are not yet documented. In the well‐studied species, the incubation temperatures for FM transitions are congruent, but MF transition temperatures differ among species. In A. mississippiensis, 100% males are produced over a range of constant incubation temperatures, whereas in C. johnstoni, only low proportions of males are produced at any constant temperature.

The thermosensitive period (TSP) for A. mississippiensis occurs during stages 21 to 24 (days 30–45 at intermediate temperatures) and coincides with gonadal differentiation. A similar scenario is suggested in other species. The TSP in A. mississippiensis (and possibly other crocodilians) encompasses the third quarter of development and occurs later than in turtles and a lizard. In A. mississippiensis as in turtles, the duration (cumulative effect) and/or the magnitude (potency effect) of incubation temperatures during the TSP predictably alter sex ratios. TSP chronologies and features which are shared among TSD reptiles suggest common, underlying mechanisms; A. mississippiensis is an appropriate model for further study. In crocodilians, clutch effects are a significant source of variation in TSD response. Hatchling sex ratios previously reported for A. mississippiensis are reconsidered in light of our new data. © 1994 Wiley‐Liss, Inc.
Temperature sensitivity of sexual differentiation of gonads in the European pond turtle: Hormonal involvement
Authors: Pieau Claude , Girondot Marc , Richard‐Mercier Noëlle , Desvages Gisèle , Dorizzi Mireille , Zaborski Patrick
Published: June 2005

In the European pond turtle, the incubation of eggs below 28°C yields 100% phenotypic males, whereas above 29.5°C 100% phenotypic females are obtained. Many data argue in favor of the involvement of steroid hormones in this phenomenon. During the thermosensitive period for sex determination, gonads are able to metabolize different steroid precursors, such as pregnenolone, progesterone, androstenedione, and dehydroepiandrosterone. Gonadal œstrogen content is higher at 30°C than at 25°C. When œstradiol benzoate (5 to 50 μg) or œstrone (100 μg) are injected into eggs incubated at 25°C before or at the beginning of the thermosensitive period, gonads differentiate into ovaries instead of testes: an ovarian‐cortex develops whereas medullary testicular cords are inhibited. Conversely, when tamoxifen (an antiœstrogen) is injected into eggs incubated at 30°C, medullary testicular cords (or tubes) differentiate. Gonadal aromatase activity during the thermosensitive period increases in an exponential fashion at 30°C, and remains very low at 25°C. When eggs are first incubated at 25°C up to a stage within this period, and then shifted to 35°C (a highly feminizing temperature) for different times, the response is also exponential, showing an amplification of aromatase synthesis. Temperature could act, directly or indirectly, on the regulation of the expression of the aromatase gene. The anti‐üullerian hormone (AMH) exerts an inhibitory effect on aromatase activity. The termination of the thermosensitive period could result in testes from an active synthesis of AMH, and in ovaries from high levels of œstrogens. © 1994 Wiley‐Liss, Inc.
The mechanism of glycine betaine regulation in response to hyperosmotic stress in oyster mitochondria: A comparative study of Atlantic and Chesapeake Bay oysters
Authors: Pierce Sidney K. , Rowland‐Faux Laura M. , Crombie Burnette N.
Published: June 2005

Mitochondria isolated from Crassostrea virginica gill take up14C‐choline and convert it to glycine betaine. Mitochondria from low salinity adapted oysters from both the Chesapeake Bay and Atlantic coast take up choline at similar rates, but the rate of glycine betaine synthesis is up to 4‐fold faster in the Atlantic oyster mitochondria. The choline uptake and glycine betaine synthesis rates are much higher (as much as 5‐fold, depending upon the concentration of choline) in mitochondria from high salinity adapted oysters from both populations compared to the rates found in the low salinity groups. Furthermore, the uptake and synthesis rates in the high salinity adapted mitochondria are similar between Atlantic and Bay oysters up to 5 mM choline. Above that concentration, the uptake and synthesis rates of mitochondria from the Atlantic oysters are greater than the rates in the Bay oysters (2. 5‐fold and 2‐fold, respectively). These results indicate that glycine betaine synthesis is regulated differently both between the two oyster populations and between the two acclimation salinities. © 1995 Wiley‐Liss, Inc.
Effects of exercise on plasma nonesterified fatty acids and free amino acids in Arctic char (Salvelinus alpinus)
Authors: Barton Kimby N. , Gerrits Martin F. , Ballantyne James S.
Published: June 2005

The plasma nonesterified fatty acids (NEFA) and free amino acids (AA) of exercised and rested Artic char (Salvelinus alpinus) were measured. Total nonesterified fatty acids, total saturated fatty acids and total monoenes were significantly elevated in the plasma of the exercised group. Plasma levels of palmitate (16: 0) were also significantly elevated in the exercised fish. No significant changes with exercise were observed in the total polyenes.

The total plasma free amino acid and total nonessential amino acid levels were significantly elevated in the exercised group. The concentrations of glutamate, alanine, taurine, and tryptophan increased with exercise. The percent contribution of total essential amino acids to total free amino acids in the exercised fish was lower than that of the rested group.

It is suggested that mobilization of specific nonesterified fatty acids and amino acids largely reflect increased oxidation of metabolic substrates by exercising red muscle. © 1995 Wiley‐Liss, Inc.
Regulation of ovarian recrudescence: Effects of social interaction and size on female lizards, Anolis carolinensis
Authors: Summers Cliff H. , Suedkamp Denise A. , Grant Teresa L.
Published: June 2005

Stressful conditions inhibit reproductive function. For example, ovarian recrudescence is slower in captive and crowded lizards, and the presence of a dominant individual inhibits reproductive activity in subordinate male lizards. However, individuals so not necessarily respond to stressors equally. This study investigated the role of social stresses on reproductive function in female Anolis carolinensis. Groups of five females were placed with a male for 1 month in 25 × 25 × 25 cm aquaria under temperature and light conditions that stimulate reproduction (14L 32°C:10D20°C). Single females sacrificed prior to treatment with simulatory temperature and light regimens, but following acclimation to cages (as initial control, without male present) showed no ovarian recrudescence. Females placed on per cage with individual males (as final control) had significant ovarian growth yielding large yolking follicles when exposed to stimulatory temperature and light. In multi‐female groups two or fewer females per group had significant ovarian recrudescence. These females also had large yolking follicles, significant uterine growth, and always weighed 2. 7 g or more. Any female in a group weighing less than 2.7 g, regardless of the number of actively cycling females in the cage, had quiescent ovaries. Chromatic and behavioral characteristics of reproductively dominant females are not similar to those of dominant males. Dominant males are significantly more often green than brown. Females with cycling ovaries are significantly more often brown. Females which are successful in maintaining ovarian functioning even in crowded conditions acquire this morphological characteristic usually associated with subordinate status in males, which may facilitate courtship behavior. These results suggest that density‐dependent and/or psychosocial stressors inhibit reproductive cycling in this species. © 1995 Wiley‐Liss, Inc.
Immunohistochemical detection of the expression of the α subunit of inhibin, TGF‐β, basic‐FGF and IGF‐II in fetal ovarian grafts grown with fetal testes beneath the kidney capsule of adult castrated male rats
Authors: Koike Satoshi , Noumura Tetsuo
Published: June 2005

In order to characterize the participation of growth factors in gonadal differentiation and development, we examined patterns of expression of the α subunit of inhibin, transforming growth factor‐β (TGF‐β), basic fibroblast growth factor (basic FGF) and insulin‐like growth factor‐II (IGF‐II) immunohistochemically in experimentally induced ovotestes. Ovotestes were derived from ovaries of fetal rats on gestational day (GD) 13 that had been co‐grafted with fetal testes (GD 17) beneath the kidney capsule of adult castrated males and examined on the 7th, 14th and 21st days after transplantation (TD). Reactivity with antibodies against the α subunit of inhibin and basic FGF was observed in the Sertoli cells in both ovotestes and testes on TD 14 and on TD7, 14 and 21, respectively. Expression of IGF‐II was also recognized in the Leydig/interstitial cells in both types of graft on TD 14 and 21. Therefore, the gonadal somatic cells in the testicular region of the ovotestes had immunohistochemical properties similar to those in the co‐grafted testes. However, the somatic cells in the ovarian region of the ovotestes had immunohistochemical profiles different from those in solitary grafted ovaries. The germ cells in the ovotestes showed some differences in patterns of expression when compared with those in co‐grafted testes and solitary grafted ovaries: expression of basic FGF was recognized in the germ cells in ovotestes on TD 21 but not in co‐grafted testes; expression of IGF‐II was recognized in the germ cells in ovotestes on TD 21 but not in solitary grafted ovaries. These results indicate that the immunohistochemical properties that reflect expression of growth factors in female gonadal somatic cells were changed to properties that resemble those of male gonads by the co‐grafted fetal testes. © 1995 Wiley‐Liss, Inc.
Wool growth rate in vitro is independent of host animal nutrition, season, and the potential mediators of photoperiod, melatonin and prolactin
Authors: Winder L. M. , Scobie D. R. , Bray A. R. , Bickerstaffe R.
Published: June 2005

In most sheep breeds, wool growth varies seasonally and is correlated with changes in photoperiod, temperature, and nutrition. Wool growth regulation by these factors may result from systemic changes, or to a response localized at the wool follicle. Possible roles of systemic and local factors have been examined here by comparison of wool growth responses in vivo and in vitro.

Wool follicles were isolated and maintained under conditions facilitating fibre growth for at least 4 days. The wool growth rate by follicles isolated regularly over a 10 month period was invariate (P > 0.10), in contrast to a seasonally varying wool growth rate by follicles from the same animals in vivo (P < 0.001). Although a high energy, high protein diet increased wool growth in vivo (P < 0.05), cultured follicles isolated from these animals showed no change in growth rate (P > 0.10). These observations suggest that the regulation of wool growth by environmental factors is extrafollicular and that there is no carryover of the in vivo growth rate when follicles are isolated and systemic signals are therefore removed.

Additional work discussed here examined the regulation of pelage by prolactin and melatonin, potential endocrine mediators of photoperiod. The fibre production rate by isolated follicles maintained in control media was not different to that of prolactin or melatonin supplemented follicles (P > 0.10). It is concluded that selective breeding of domesticated sheep has suppressed the response of follicles to regulation by prolactin and melatonin. Studies currently underway using in situ RT‐PCR will provide further characterization of this conclusion. © 1995 Wiley‐Liss, Inc.
Manipulating melatonin in red deer (Cervus elaphus): Differences in the response to food restriction and lactation on the timing of the breeding season and prolactin‐dependent pelage changes
Authors: Heydon M. J. , Milne J. A. , Brinklow B. R. , Loudon A. S. I.
Published: June 2005

In this study, we investigated the influence of food availability and lactation upon seasonality in red deer. This was examined by testing the hypothesis that advancing the timing of breeding and autumn moult using the hormone melatonin will be prevented when the food availability of lactating hinds is severely restricted. This hypothesis was rejected. Implanting 1 g of melatonin between June 22 and November 30 resulted in advances in the timing of the onset of ovarian activity and winter coat growth of 18 and 35 days, respectively. Whilst the onset of ovarian activity was unaffected by lactation and restricted food availability, these factors significantly delayed the winter coat growth by 20 days. The date of onset of winter primary fibre growth was negatively correlated to plasma concentrations of the hormone prolactin in July. We suggest that seasonal changes in the growth of primary hair fibres are modified by two mechanisms: the increasing duration of melatonin secretion, as day lengths decline, which depresses prolactin secretion, and low nutrition, which elevates prolactin secretion in lactating deer.

To conclude, we have demonstrated that the sensitivity of red deer to photoperiodic influences is preserved in lactating animals at low levels of nutrition, and that the timing of the onset of the breeding season and winter coat growth differ detectably in their sensitivity to nutrition and lactation. © 1995 Wiley‐Liss, Inc.
Descriptive kinetics of the seminiferous epithelium cycle and genome size in the mole Talpa occidentalis (Insectivora)
Authors: Sánchez A. , Stamatopoulos C. , Redi C. A.
Published: June 2005

The male germ cell cytodifferentiative process of the mole Talpa occidentalis is described. Cytochemical procedures were used 1) to follow acrosome formation and spermatid differentiation, dividing the seminiferous epithelium cycle into ten stages, each characterized by typical germ cell‐to‐cell associations, and recognizing 13 steps in spermatid differentiation; 2) to monitor, in situ, histones replacement by protamines at step 11 of the spermiogenic process.

The seminiferous epithelium cycle of the mole has the basic histological features present in all mammals and appears rather similar to that of the common shrew (Sorex araneus), the only one so far known among Insectivora. The metabolism of the DNA‐associated proteins reveals that protamines replace histones during the late steps (11–13) of spermiogenesis, mRNA for protamines having been synthesized at an earlier step (assuming that in the mole this occurs at the first spermiogenic steps, as in the house mouse).

In addition the genome size (5.0 pg) and the AT/GC ratio (1.3) were evaluated. © 1995 Wiley‐Liss, Inc.
Characterization of the chemiluminescence measured in hemocytes of the eastern oyster,Crassostrea virginica
Authors: Austin Kellie A. , Paynter Kennedy T.
Published: June 2005

Hemocytes of the Eastern oysters,Crassostrea virginica, produce reactive oxygen intermediates (ROIs) during phagocytosis to destroy foreign cells. Although evidence suggests that oyster hemocytes generate superoxide anions (O2−) following phagocytic stimulation, the production of other ROI species such as hydrogen peroxide (H2O2), singlet oxygen (1O2), hydroxyl radical (·OH), and hypochlorous acid (HOCl) has not been directly investigated. In this study, ROI production by oyster hemocytes was measured by quantifying the production of chemiluminescence (CL) amplified with different luminescent probes. The ROIs involved in CL production were identified by testing the effects of scavengers and inhibitors of particular ROI species on CL. Taurine completely inhibited luminol‐dependent CL, indicating that HOCl production was primarily responsible for the CL generated by hemocytes during phagocytosis of yeast granules. In addition, azide strongly inhibited luminol CL, implicating the involvement of myeloperoxidase in the production of HOCl and the resulting CL. Superoxide dismutase partially inhibited CL, indicating that superoxide ions were also produced and contributed to CL. Luminol CL was significantly higher in hemocytes from oysters heavily infected with the parasitePerkinsus marinusand remained completely inhibitable by taurine suggesting that HOCl production was enhanced by infection. Last, the concentration of taurine measured in oyster hemolymph was sufficient to quench a significant amount of the HOCl generated by the hemocytes and may reduce the effectiveness of the oyster's defense response to infections. © 1995 Wiley‐Liss, Inc.
Self‐fertilization of hermaphrodites of the teleostClarias lazereaafter oral administration of 17‐α‐methyltestosterone and their offspring
Authors: Liu Shaojun , Yao Zhanzhou
Published: June 2005

After culture for 28 months, six specimens of Clarias lazera, which had received 17‐α‐methyltestosterone (MT) orally at a concentration of 30 m̈g per gram of diet for 60 days after hatching, reached sexual maturity and performed self‐fertilization in the absence of males. Under the light microscope, scanning electron microscope, and electron microscope, we examined the ova and moving sperm stripped from each of the six hermaphrodites. Testes and ovaries, which reached maturity synchronously, were found in one individual after self‐fertilization. The testes, which consisted of many lobules in which there were numerous sperm, were basically similar to the mature normal testes. However, the testes had unusual characteristics, such as the absence of spermatogonia on the walls of the lobules, looser junctions between adjacent lobules, a less dense distribution of sperm, and a few abnormal sperm (two‐headed sperm). All offspring produced by the six hermaphrodites were female. The all‐female offspring of the hermaphrodites provide evidence that the female ofClarias lazerais homogametic. © 1995 Wiley‐Liss, Inc.
Biological setting events for self‐injury
Authors: Carr Edward G. , Smith Christopher E.
Published: June 2005

Self‐injurious behavior typically occurs in response to specific antecedent stimuli that predict the occurrence of such desirable consequences of the behavior as obtaining attention from others, escaping aversive situations, and securing preferred foods, objects, and activities. Setting events constitute an additional controlling variable, altering the probability that a specific antecedent stimulus will evoke self‐injury. We discuss the influence of several biological factors, including menses, otitis media, fatigue, allergies, and constipation, that may serve as setting events. We also present a model which suggests that these events alter the functional properties of the antecedent stimuli that control self‐injurious behavior, thereby strengthening the specific consequences that maintain the behavior. One implication of this model is the likelihood that effective intervention will have to have multiple components, addressing both the biological and environmental variables that control the behavior. A second implication is that greater collaboration between medical and psychological or educational practitioners will be necessary in order to address the multiple factors that affect self‐injury. © 1995 Wiley‐Liss, Inc.
A theoretical analysis of the role of hyperarousal in the learning and behavior of fragile X males
Authors: Cohen Ira L.
Published: June 2005

Fragile X syndrome, the most common form of inherited mental retardation, is associated with a broad spectrum of cognitive and behavioral impairments. Researchers have noted a characteristic behavioral profile consisting of social avoidance, as well as verbal and motor repetitive behaviors, in a subgroup of males with fragile X syndrome. Although these behaviors are evident in their most extreme form in males having both fragile X syndrome and autism, milder variants are evident in nonautistic males as well. Clinical data we have collected suggest that the severity of these agitated behaviors starts increasing during adolescence. These data suggest fragile X males have problems with arousal modulation. It is hypothesized that these arousal problems have an impact on both the acquisition and display of cognitive and adaptive skills. Neurocomputational issues that may be relevant to understanding these cognitive and emotional phenomena are discussed. © 1995 Wiley‐Liss, Inc.
Studies of the development of congenital anomalies in embryos of riboflavin‐deficient, galactoflavin fed rats. II. Role of the terminal electron transport systems
Authors: Aksu Oguz , Mackler Bruce , Shepard Thomas H. , Lemire Ronald J.
Published: June 2005

Studies of the tissues of embryos and fetuses of rats treated with a riboflavin‐deficient, galactoflavin‐augmented diet during pregnancy were performed, and demonstrated that the activities of the succinic and DPNH oxidase systems (the terminal electron transport systems) were markedly reduced from control values during the critical period of development (days 12 thru 16 of gestation). The activities of the electron transport systems of placental tissue and maternal heart tissue were unaffected during the same period, suggesting that fetal tissue is particularly susceptible to the effects of riboflavin deficiency.
Morphogenesis of cleft palate induced by exogenous factors. III. Intraamniotic application of hydrocortisone in mice
Authors: Dostál M.
Published: June 2005

In analyzing the morphogenesis of an experimentally induced congenital defect, estimation of the direct effect of the teratogen on offspring is of a great importance. In order to avoid the probable modification of the terato‐genic action of a given substance caused by the placental barrier and maternal metabolism, it is useful to apply the teratogen directly into the anmiotic sac of the embryo or fetus. However, it has been claimed that puncture of the amniotic sac both in mice and rats may itself induce cleft palate. An intraamnioticinjection method worked out in our laboratory diminishes the occurrence of cleft palate caused by nonspecific factors to a uniform and fairly negligible level. The application is performed by means of a glass micropipette provided with sharp, beveled tip. Using this method hydrocortisone was injected into the amniotic sacs of embryos and fetuses of randombred H‐Velaz mice, and it was shown that administration on day 12, 13, or 14 of gestation induced cleft palate. The direct action of corticoids upon the morphogenetic system of the palatine shelves is therefore supposed.
Teratogenic effects of rotenone on the early development of chick embryos in vitro
Authors: Rao K. Vasudeva , Chauhan S. P. S.
Published: June 2005

Chick embryos at five developmental stages ranging from full primitive streak to six pairs of somites were exposed in vitro to the action of 1 μg/ml rotenone for 15 minutes. The syndrome of defects caused by this treatment was described. Protection experiments using various chemicals applied to the rotenone‐treated embryos indicated that the biochemical lesion caused by rotenone is an inhibition of the respiratory chain. Rotenone did not seem to interfere with the primary organizer of the embryo as shown by grafting experiments. The general similarity of the rotenone syndrome and that caused by other teratogens was discussed and it was suggested that different biochemical lesions caused by a variety of teratogens may lead to apparently similar syndromes.
Comparative teratogenicity of pyrimethamine in rats and hamsters
Authors: Sullivan George E. , Takacs Eva
Published: June 2005

Pyrimethamine, a drug used in the treatment of toxoplasmosis, was much less teratogenic in golden hamsters than in Wistar rats. About 70% of rat fetuses were killed or malformed by administration of single oral doses of 5 mg to pregnant females. Less than 10% of hamster fetuses died or were malformed following single doses to the mother of 20 mg, which on a mg/kg basis was eight to nine times greater than that given to rats. In the rats repeated daily doses of 0.5 mg per female were severely teratogenic. The incidence of dead and abnormal fetuses in rats treated with 5 mg pyrimethamine was markedly reduced, from about 70 to 10%, by single intraperitoneal injections of 6 mg folinic acid; this result suggests that folinic acid might be potentially of value in lessening the teratogenic risk that may exist when pyrimethamine is employed in toxoplasmosis therapy during early pregnancy.
A meiotic cytogenetic study in mice of a commonly used tranquilizer reported to concentrate in mammalian follicular fluid
Authors: Jagiello Georgiana , Ducayen Mercedes B. , Lin J. S.
Published: June 2005

The ability of meprobamate, a commonly used tranquilizer, to be concentrated in human ovarian follicular fluid and to block superovulation in the mouse prompted an examination of its potential as a meiotic mutagen. Examination of in vitro meiotic behavior of mouse ova in a medium containing 1–10,000 μg/ml of meprobamate revealed that at 500 μg/ml abnormal second metaphase configurations were induced and that at a concentration of 750 μg/ml the progression of meiosis was essentially stopped. Superovulation was blocked in young mice each treated with 5 mg meprobamate and examination of intrafollicular oocytes principally revealed normal second metaphase configurations with first polar bodies. A single iv or chronic treatment throughout the time required for total maturation of a mouse follicle did not affect subsequent meiotic maturation of ova. The data suggest that the in vitro effects of the tranquilizer on mouse ova are prevented in vivo by an unknown barrier or mechanism within the ovarian follicle, and that at relatively high doses no detectable chromosome change in ova would be expected.
Skullbase malformations in rat fetuses with hypervitaminosis A‐induced exencephaly
Authors: Geelen J. A. G.
Published: June 2005

Exencephalic fetuses (16th–20th day), offspring of female Wistar rats treated with vitamin A palmitate orally during pregnancy, were studied in serial sections. The median part of the skullbase of the rat is formed by the basioccipital, basisphenoid, and presphenoid. In exencephalic fetuses the basioccipital had a normal shape; the hypophyseal fossa in the basisphenoid was too deep; the presphenoid was malformed. The angle between the cervical vertebral column and basioccipital was increased and those between the basioccipital and basisphenoid, and the basisphenoid and presphenoid were reduced. As a result the longitudinal axis of the skullbase was shortened. In all exencephalic fetuses the pontine and cervical flexures were less well marked than in controls. No anomalies of the rostral part of the notochord were observed. It is concluded that there is a relation between abnormal flexures of the neural tube and the malformation of the skullbase. The resemblance of the skullbase in human anencephaly and rat exencephaly is emphasized.
Congenital heart disease in dogs: Epidemiologic similarities to man
Authors: Mulvihill John J. , Priester William A.
Published: June 2005

In a study of 700 congenital cardiac defects in dogs there were similarities, anatomic and epidemiologic, to defects occurring in man. Marked excesses of certain anomalies observed in specific breeds can serve as models for genetic and environmental studies.
Protective effect of deoxycytidylic acid (CdMP) on hydroxyurea‐induced malformations in rats
Authors: Chaube Shakuntala , Murphy M. Lois
Published: June 2005

Single ip injections of 500 mg/kg hydroxyurea (HU) to 11‐day pregnant rats produced minimal fetal mortality and malformations of the limbs, palate, jaw, and tail in 98.8% of fetuses surviving to day 21 of gestation. Simultaneous administration of 500 mg/kg HU and 700 mg/kg deoxycytidylic acid (CdMP) provided complete protection against HU teratogenesis. Lower doses of CdMP (3.7–500 mg/kg) gave partial, dose‐related, protection, as indicated by increased frequency of normal survivors and decreased severity of specific malformations. Maximal protection was provided to the forepaw and jaw and minimal to the tail. In experiments in which 700 mg/kg CdMP were given 15–60 minutes after or up to 150 minutes before HU administration, its protective effect gradually diminished with lengthening of time between the administration of the two compounds. The incidence and manifestation of individual malformations in both sets of experiments were time related. When a mixture of 700 mg/kg of CdMP and 500 mg/kg of HU was left at room temperature for 15 minutes before injection, the protective effect of CdMP was diminished by 15.1%. When the effects of several pyrimidine compounds were equated on the basis of biochemically equivalent doses (mmol/kg), among the cytidine derivatives CdMP was more effective at all doses than cytidine or deoxycytidine. All cytidine compounds gave greater protection than the uridine compounds, whereas thymidine and thymidylic acid did not protect the fetal rat against HU‐induced malformations.
Normal production of cartilage glycosaminoglycan in mice homozygous for the chondrodysplasia gene
Authors: Stephens Trent D. , Seegmiller Robert E.
Published: June 2005

Biochemical analysis of a lethal recessive mutation affecting chondrogenesis in mice further delineated the mechanism by which this pleiotropic gene acts. Cartilage from late fetuses homozygous for chondrodysplasia (cho/cho) were terminally labeled in vitro with Na235SO4, [14C] glucosamine, and [14C] glucose. Rates of precursor incorporation; tissue contents of uronic acid, amino sugar, and protein; and molecular weight of glycosaminoglycan were determined and found normal compared with control littermate cartilage. Samples from mutants, agitated overnight in distilled water and assayed for loss of incorporated 35S, showed between 47 and 77% of control activity. The rinse water from mutant cartilage contained correspondingly more 35S than did control. Chromatographic analysis of both tissue‐bound and water‐diffusible macro‐molecules confirmed that glycosaminoglycan and protein backbone were intact. Because the molecular content and rates of precursor incorporation were normal the results suggested that the cho gene does not alter net synthesis of glycosaminoglycan. The observation that water facilitates extraction of a glycosaminoglycan‐protein complex of normal molecular weight suggests that the defect in chondrogenesis results from defective interaction of proteoglycan and some other matrix constituent. In view of a previous report that collagen fibrils of mutant cartilage are atypically large and natively banded the site of chondrogenic defect might be the interaction between proteoglycan and collagen.
Warfarin‐associated embryopathy in a 17‒week‐old abortus
Authors: Barr Mason , Burdi Alphonse R.
Published: June 2005

Histological and anthropometric studies were made of the hands and face of a 17‐week‐old (postmenstrual) human fetus that was exposed to warfarin throughout gestation. The fetus had marked nasal hypoplasia and the facial cartilages contained discrete foci of abnormal cartilage. When compared with agematched control fetuses hand pattern profile analysis showed that the brachydactyly was due to shortening of the terminal phalanges. Histologically chondrogenesis was disordered in the carpals and phalanges, with the most deviant development occurring at the distal ends of the terminal phalanges. In none of the areas of abnormal cartilage was there evidence of hemorrhage or hemosiderin deposition. It is our contention that warfarin is teratogenic in human beings and that its teratogenicity is not due to focal hemorrhage.
Preventive effect of riboflavin and ATP on the teratogenic effects of the phenothiazine derivative T‐82
Authors: Horvath Cecilia , Szonyi Laszlo , Mold Katalin
Published: June 2005

To examine the hypothesis that the teratogenic effects of the phenothiazine derivative T‐82 are due to its causing a riboflavin deficiency day 11 or 12 pregnant CB Wistar rats were each given 2,000 mg/kg T‐82 po plus 100 mg/kg riboflavin ip, 12.4 mg/kg ATP ip, or both. The rates of fetal mortality and external malformations were significantly decreased in all supplementation experiments. The frequencies of cleft palate, micrognathia, and micromelia were unchanged but those of ectopic testis and hydrops fetalis were significantly increased in the group treated with T‐82 and ATP on day 12.
Growth inhibition of human embryonic and fetal rat bones in organ culture by rubella virus
Authors: Heggie Alfred D.
Published: June 2005

Paired organ cultures of metacarpal, metatarsal, and long bones of previable human embryos, of 7 to 12 weeks' gestation, and tibias of 17‐day rat fetuses were inoculated with live or ultraviolet‐inactivated rubella virus or control fluids and the growth of the bones was measured by increase in wet weight. In several cultures the ability of the human bones to incorporate 35S, a measure of rate of mucopolysaccharide synthesis, was tested. Growth of human and rat bones was retarded in cultures inoculated with live virus but not in cultures inoculated with inactivated virus or control fluids. Mean 35S uptake was increased by approximately 25% in virus‐inoculated cultures of bones of 9‐ to 12‐week human embryos. No histological abnormalities were seen. These findings suggest that (1) defective bone growth in congenital rubella is a direct effect of viral infection of bone, (2) a disorder of mucopolysaccharide syntheses may contribute to the osseous lesions that occur in this disease, and (3) organ cultures of human embryonic and fetal rat bones may serve as convenient models for studying the pathogenesis of this virus‐induced congenital osteopathy.
Temporal, morphological, and genetic responses of avian embryos to Azodrin, an organophosphate insecticide
Authors: Schom C. B. , Abbott U. K.
Published: June 2005

The effect of Azodrin on avian development was studied using a bobwhite quail line and two chicken lines—a single comb White Leghorn (SCWL) and an Australorp line. The bobwhite quail embryos did not respond to injections of Azodrin until stages 22 to 23 (6 days of incubation); the SCWL embryos, not until stage 18 (3 days of incubation) with increasing susceptibility through stage 20. The threshold concentration, at stage 19, for the SCWL was 0.4 mg/kg, for the Australorp, less. Within one hour of treatment stage‐20 embryo shape was altered. There was, however, no immediate response from embryos treated earlier. The effect appeared as a reduced growth rate in the cervical flexure, and may be mediated by interference with the normal energy balance. The response, once initiated, was continuous through 10 days of incubation.
The effect of vidarabine on the development of the offspring of rats, rabbits, and monkeys
Authors: Schardein James L. , Hentz David L. , Petrere Judith A. , Fitzgerald James E. , Kurtz Stanley M.
Published: June 2005

The effect of vidarabine, a new antiviral agent, on the offspring of rats, rabbits, and monkeys was studied by varying routes of administration during several periods of gestation.

Vidarabine demonstrated a dose‐related teratogenic effect in rats when given parenterally at doses of 30 mg/kg and greater. The drug was also teratogenic in the rabbit at dosages of 5 mg/kg and greater by the parenteral route or when applied topically in 10% concentration to 5 or 10% of the body surface area. The pattern of malformation was similar in the two species, and consisted of multiple, severe abnormalities of the head, trunk, and limbs.

The drug had no demonstrable teratogenic effect in a limited study in the rhesus monkey; nor were there adverse effects on the offspring when it was applied intravaginally to pregnant rats in the perinatal period.
Craniosynostosis. II. Coronal synostosis: Its familial characteristics and associated clinical findings in 109 patients lacking bilateral polysyndactyly or syndactyly
Authors: Hunter Alasdair G. W. , Rudd Noreen L.
Published: June 2005

This paper is the second part of a survey of 370 patients with Craniosynostosis. It concerns 109 patients with coronal synostosis, with or without additional suture involvement who lacked polysyndactyly or syndactyly. Bilateral and unilateral coronal synostosis occurred with approximately equal frequency and there was an excess of males in both groups. Multiple suture involvements was frequent in patients with bilateral synostosis, but was uncommon in those with unilateral involvement. Those patients with bilateral synostosis and additional suture involvement were treated later than those with isolated bilateral synostosis and a possible explanation for this finding is discussed. Forty‐seven percent of patients with bilateral synostosis had additional major malformations. Cardiac malformations were significantly more frequent than would be 'expected by chance. Thirty‐five percent of patients with unilateral involvement had major malformations. Twenty‐six percent of those with bilateral and ten percent of those with unilateral synostosis were mentally retarded, but retardation was found to be associated either with increased frequency of major malformations or with a complex medical history. Mental retardation is uncommon in simple, uncomplicated coronal synostosis. Twelye of the 104 families showed a positive family history; nine with vertical and three with horizontal transmission. An admixture of unilateral and bilateral suture involvement was the rule, and families with involvement limited to unilateral synostosis did not occur. Certain patterns of characteristic familial minor malformation, particularly of the hands, allow recognition of a number of these familial cases. The recurrence risks for coronal synostosis are discussed.
The acardiac anomaly
Authors: Benirschke Kurt , Harper Virginia Des Roches
Published: June 2005

Karyotype analysis of a premature human acardiac twin disclosed normal chromosomes. A review of previous cytogenetic, placental and animal studies suggests that chromosomal errors are not the cause of the acardiac anomaly. Rather, they point to the placental vascular anastomoses as the principal pathogenetic event.
The Klippel‐Feil Anomalad as part of the fetal alcohol syndrome
Authors: Lowry R. B.
Published: June 2005

A brother and sister are described with malformations and handicaps consistent with both the Klippel‐Feil Anomalad and the Fetal Alcohol Syndrome. The mother was known to be a chronic alcoholic throughout both pregnancies. It is suggested that these anomalies are not purely fortuitous but rather that maternal alcoholism may cause errors in cervical vertebrae segmentation.
Alpha‐fetoprotein and albumin in experimentally‐induced exencephaly in the rat
Authors: Smith Carol J. , Kelleher Philip C.
Published: June 2005

Alpha‐fetoprotein and albumin were quantified in the sera and amniotic fluids from control, Vitamin A‐treated non‐exencephalic and Vitamin A‐treated exencephalic rat fetuses. Exencephaly was associated with amniotic fluid alpha‐fetoprotein concentrations which were significantly elevated over those of Vitamin A‐treated non‐exencephalic and of untreated fetuses. Amniotic fluid albumin concentrations also were higher in the exencephalic fetuses than in the non‐exencephalic fetuses. Serum alpha‐fetoprotein and albumin concentrations were lower in the exencephalic than in the non‐exencephalic fetuses. The results are consistent with simple diffusion across a defective barrier as the cause of elevated amniotic fluid alpha‐fetoprotein concentrations in the presence of open neural tube defects. This experimental model of neural tube defects results in changes in amniotic fluid alpha‐fetoprotein similar to those changes found in human amniotic fluid alpha‐fetoprotein concentrations in the presence of neural tube defects.
Arsenate‐induced renal agenesis in rats,
Authors: Burk Dorothy , Beaudoin Allan R.
Published: June 2005

The developmental origin of arsenate‐induced renal agenesis was investigated. Pregnant Wistar rats were each injected once ip with 45 mg/kg sodium arsenate at day 10 (sperm day = day 0). Pregnancy was terminated at various times following injection and the embryos recovered and serially sectioned. Renal agenesis resulted when the mesonephric duct failed to give rise to a ureteric bud with subsequent failure of induction of the metanephric blastema. The underlying defect was retardation in growth of the mesonephric duct, first observed 48 hours after arsenate injection. A shortened mesonephric duct also resulted in a failure of the mesonephros to attain normal size and in the male resulted in absence of the ductus deferens, seminal vesicle and a variable portion of the epididymis. Due to the intimate association of the mesonephric and growing paramesonephric ducts, a shortened mesonephric duct resulted in a shortened paramesonephric duct with resultant lack of a uterine horn.
The fine structure of ventricular cells in the brains of mouse embryos homozygous for the loop‐tail gene
Authors: Wilson Doris B.
Published: June 2005

The neural tube in normal (+/+), heterozygous (Lp/+), and abnormal (Lp/Lp) mutant mouse embryos ranging in age from 10 to 12 days of gestation was studied by means of transmission electron microscopy. In the abnormal embryos, ventricular cells in defective regions of the brain show distortions and crowding together of internal cellular processes and a decrease in blebs and bulbous projections, as compared with their normal counterparts. At 12 days' gestation the abnormal brains show a scarcity of the T‐shaped internal cellular processes characteristic of normal brains. The abnormal brains also show increased amounts of intercellular space and extensive gaps between the cells, particularly in basal regions. There are no striking differences between the normal and abnormal brains at 10 to 12 days' gestation with respect to the appearance and distribution of cilia, microfilaments, microtubules, tight junctions, and ribosomes.
Congenital absence of the heart: Observation of human funiculopagous twinning with insertio funiculi furcata, fusion, forking, and interpositio velamentosa
Authors: Averback P. , Wiglesworth F. W.
Published: June 2005

An anatomic and radiologic study of a normal and acardius twinning with a single placenta is presented with literature review. The fetus was unusually well‐developed with an almost normal skeletal and brain formation, a normal genito‐urinary tract, and an absence of liver, spleen, lungs, and pancreas. The heart was absent but the great arteries, single aorta, and veins were present. The placentation is described as funiculopagous with insertio funiculi furcata, fusion, forking and interpositio velamentosa, and the latter may account for the fusion of the two circulations in this instance with the possibility that the heart was never present. The present and other observations of funiculopagous twins with two amniotic sacs suggest that the forked cord twin anomaly may occur earlier than generally recognized.
Teratogenicity of adriamycin and daunomycin in the rat and rabbit,
Authors: Thompson Daniel J. , Molello Joseph A. , Strebing Robert J. , Dyke Irene L.
Published: June 2005

The antitumor drugs adriamycin and daunomycin were evaluated for effects on embryonal and fetal development in the rat and rabbit. Doses of adriamycin ranging from 1‐2 mg/kg/day or daunomycin ranging from 1‐4 mg/kg/day were administered ip to pregnant rats on days 6‐15, 6‐9, 9‐12 or 12‐15 of gestation. Both drugs were teratogenic in the rat, particularly when administered on days 6‐15 or 6‐9 of gestation. Relatively few anomalies resulted from treatment on days 9‐12 or 12‐15. On a mg/kg basis, adriamycin was the more potent teratogen, producing major anomalies at doses as low as 1.25 mg/kg. Similar anomalies, but at a lower incidence, were produced by daunomycin at dose levels of 4 mg/kg. Characteristic malformations included esophageal and intestinal atresia, tracheo‐esophageal fistula, hypoplasia of the urinary bladder and various cardiovascular anomalies. Neither drug was teratogenic when given iv to rabbits at doses up to and including 0.6 mg/kg/day on days 6‐18 of gestation, but a high incidence of abortion occurred in rabbits treated with adriamycin.