bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental consequences of neuromuscular junctions with reduced presynaptic calcium channel function
Authors: Xing Bin , Long A. Ashleigh , Harrison Douglas A. , Cooper Robin L. 
Published: June 2005

AbstractEvoked neurotransmitter release at the Drosophila neuromuscular junction (NMJ) is regulated by the amount of calcium influx at the presynaptic nerve terminal, as for most chemical synapses. Calcium entry occurs via voltage‐gated calcium channels. The temperature‐sensitive Drosophila mutant, cacTS2, has a reduced amount of calcium entry during evoked stimulation. We have used this mutation to examine homeostatic regulatory mechanisms during development of the NMJ on muscle 6 within the developing larva. The amplitude of the excitatory postsynaptic potentials are reduced for both the Ib and Is motor neurons in 3rd instar larvae which have been raised at 33°C from the 1st instar stage. Larvae raised at 25°C and larvae pulsed at 33°C from the late 2nd instar for various lengths of time show a reduced synaptic efficacy as a 3rd instar. The results indicate that the nerve terminal cannot fully compensate physiologically in the regulation of synaptic transmission during larval life for a reduced amount of evoked calcium entry. Morphological comparisons of Ib and Is terminals in relation to length and numbers of varicosities are significantly reduced in cacTS2, which also suggests a lack in homeostatic ability. These findings are relevant since many deficits in synaptic transmission in various systems are compensated for either physiologically or structural over development, but not in this case for reduced calcium entry during evoked transmission. Synapse 57:132–147, 2005. © 2005 Wiley‐Liss, Inc.
Picomolar concentrations of hibernation induction delta opioid peptide [D‐Ala2,D‐Leu5]enkephalin increase the nerve growth factor in NG‐108 cells
Authors: Tsai Shang‐Yi , Hayashi Teruo , Su Tsung‐Ping 
Published: June 2005

AbstractThe delta opioid peptide [D‐Ala2,D‐Leu5]enkephalin (DADLE) has been shown to be a neuroprotective agent via mechanisms that are not totally understood. We previously demonstrated that the i.p. injection of DADLE in mice causes an increase of nerve growth factor (NGF) in the brain. To further clarify the NGF‐increasing action of DADLE, we examined here the NGF‐increasing effect of DADLE in vitro, using cultured NG‐108 cells. DADLE dose‐dependently increases the immunoreactive level of NGF in NG‐108 cells in a bell‐shape manner, with the effective DADLE concentrations in the picomolar range (0.01–100 pM). Also, DADLE at 1 pM selectively increases c‐Jun and c‐Fos, but not c‐Rel. These results indicate that DADLE is one of the most potent agents in increasing the NGF in the biological system and that this action of DADLE involves selective increases of c‐Jun and c‐Fos, transcription factors that promote the NGF expression. Synapse 57:179–181, 2005. Published 2005 Wiley‐Liss, Inc.
Trypan blue in the rat embryo
Authors: Davis Howard W. , Gunberg David L. 
Published: June 2005

AbstractSeventy‐five embryos were obtained from rats 48, 72, or 96 hours after injection of the maternal animal with the teratogenic dye trypan blue on day 9 of gestation. Low‐magnification examinations of these fixed and cleared embryos revealed distinct deposits of trypan blue in the caudal segments of the gut. Light‐microscope examinations revealed dye deposits in the gut endoderm and cells of the adjacent mesenchyme. The implications of these observations are discussed.
Two familial translocations involving the 6–12 group. With meiotic studies in one
Authors: McDermott A. , Insley J. , Rushton D. I. , Edwards J. H. 
Published: June 2005

AbstractTwo infants are reported with congenital malformtions. In each case, the infant had a karyotype containing an abnormal chromosome and one parent was a balanced structural heterozygote.Data on the phenotypes of the propositi are presented with familial studies on blood group markers and chromosome analysis, including paternal meiosis in the case in which the father carried the balanced translocation.In the first case, the infant had a duplication of part of the long arms of one of the 6‐X‐12 group, probably number 11; the mother had a balanced interchange probably between chromosome 11 and 12. In the second, the infant had a duplication of part of the long arms of another chromosome in the 6‐X‐12 group, probably number 8, while the father had a balanced interchange between this chromosome and number 18. Meiotic studies indicated that the interchange chromosomes usually formed a quadrivalent during the first meiotic division; when univalents formed, the cells tend to degenerate.
Teratology in the Macaca mulatta
Authors: Courtney K. D. , Valerio D. A. 
Published: June 2005

AbstractThe effects of acetylsalicylic acid, meclizine hydrochloride, methamphetamine hydrochloride, clomiphene citrate, vincristine sulfate, and 6‐aminonicotinamide on fetal development of the Macaca mulatta were studied.Two monkeys administered acetylsalicylic acid 40 mg/kg/day from the 25th day of gestation to term produced normal young. Seven pregnant monkeys given meclizine hydrochloride 10 mg/kg/day during various five‐day intervals had normal progeny. Five monkeys given methamphetamine hydrochloride 0.5 mg/kg/day from implantation to term had four normal young and one abortion. Clomiphene citrate administered to 18 pregnant monkeys during various stages of organogenesis resulted in 16 normal offspring and two stillbirths.Two of the five monkeys that received vincristine sulfate produced offspring with congenital malformations. One, given a single injection of 0.175 mg/kg on the twenty‐ninth day of gestation, had an offspring with encephalocele. One administration of 0.15 mg/kg on the twenty‐seventh day of gestation produced syndactyly in the offspring of another. The other monkeys, which received 0.15 or 0.20 mg/kg on the twenty‐eighth, thirty‐third, or thirty‐fourth day of gestation, produced normal offspring.Seven monkeys were treated with 6‐aminonicotinamide at different stages of gestation. Four, treated from the twenty‐sixth to twenty‐ninth days, aborted, the other three had normal young.Retrospective studies of therapeutic agents used at various times during pregnancy in monkeys in the colony have shown that hydroxyprogesterone caproate (Delalutin), chloramphenicol succinate (Chloromycetin), lincomycin hydrochloride (Lincocin), and benzathine penicillin G and procaine penicillin G (Longicil) have no apparent effect on the developing monkey fetus.
Congenital malformations in the rat following induced hyperthermia during gestation
Authors: Edwards M. J. 
Published: June 2005

AbstractHyperthermia induced in pregnant rats by exposures for 40 to 60 minutes in an incubator that raised deep body temperatures from 38.1 ± 0.51 to 42.7 ± 0.62°C produced increased fetal resorptions, retardation of growth, and a number of development defects. Grossly apparent fetal malformations included microphthalmia following hyperthermia on day 9 of pregnancy, anencephaly on day 10, and defects of tails, limbs, toes, palate, and body on days 12 to 14.
Effects of N‐nitroso‐N‐methylurea on enzymatic ontogeny associated with teratogenesis
Authors: Johnson E. Marshall , Lambert Carol 
Published: June 2005

AbstractThe teratogenic effects of N‐nitroso‐N‐methylurea on the rat embryo were investigated. Skeletal malformations were produced in rat embryos by a dose of 20 mg/kg of maternal body weight on day 13 of pregnancy. The structurally malformed fetuses had multiple malformations including: clubfeet, syndactyly, cleft palate, micrognathia, crooked tail, and hydrocephalus. Drug administered on day 8 or 10 at dosages of 5–20 mg/kg gave no malformations at term but tended to increase fetal mortality. A dose of 20 mg/kg on day 13, however, resulted in a high incidence of congenital malformations but did not increase the resorption rate. To correlate the structural malformations with biochemical changes, zone electrophoretic separation of several enzyme systems was carried out in starch and polyacrylamide gels. Variations from the normal isozyme patterns of lactate dehydrogenase, glucose‐6‐phosphate dehydrogenase, and nonspecific esterases were found in abnormally developing embryos and organs.
Sporadic congenital malformations of newborn inbred mice
Authors: Kalter Harold 
Published: June 2005

AbstractA retrospective study was made of sporadic congenital malformations in newborn mice of nine inbred strains maintained in this laboratory. Young of seven of the strains had externally observable anomalies. In four the frequency was 0.1–0.5% and the defects formed no obvious pattern. In another it was about 4% and consisted mostly of preaxial polydactyly of the forefoot.In the remaining two the frequency was greater and some of the malformations appeared to constitute particular syndromes. In the C57BL/6JKt strain the overall frequency of malformed offspring was 10.1% and the abnormalities included eye defects, polydactyly, and otocephaly. Those of the eye (microphthalmia and anophthalmia) were commonest and affected females and right eyes much more often than males and left ones. In the A/JKt strain the total frequency of malformed offspring was 10.4% and the abnormalities included cleft lip with or without cleft palate, open eyelid, and polydactyly. Cleft lip was commonest and did not show a sex or side preference.The use of inbred strains to investigate the etiology of sporadic congenital malformations of probable multifactorial origin is to be encouraged.
Oxygen consumption in normal and trypan blue‐treated chick embryos
Authors: Kaplan Stanley , Johnson E. Marshall 
Published: June 2005

AbstractA teratogenic dose of trypan blue (1% dissolved in saline) was injected into the yolk sac of 48‐hour chick embryos. Twelve hours later the embryo preparations (embryo plus area opaca) were isolated and placed in Warburg vessels in a protein‐free culture medium containing glucose and a buffered saline. Oxygen consumption was measured in these dye‐treated preparations and in two classes of controls, unopened and saline‐injected.Qo2 (μl O2 consumed/mg dry wt/hr) in trypan blue‐treated preparations was significantly higher than in either class of controls. This is apparently a result of two combined effects of the dye on the tissues studied: (1) a true increase in oxygen consumption; and (2) a decrease in dry weight.These results show that the teratogenic effects of trypan blue can be detected at the biochemical level within 12 hours of treatment. It is suggested that trypan blue acts as an uncoupling agent on the tissues of the early chick embryo.
Respiratory changes observed in abnormally developing rat embryos
Authors: Netzloff M. L. , Johnson E. M. , Kaplan S. 
Published: June 2005

AbstractAbnormally developing embryos from maternal rats treated with the teratogenic folic acid antagonist 9‐methyl pteroylglutamic acid were evaluated for their capacity to consume oxygen in a Warburg constant volume respirometer. Experimental and control embryonic preparations, with extraembryonic membranes intact, were maintained individually in culture media during the full time course of a manometric determination.During the period of the vitamin deficiency the experimental embryonic preparations were found to consume oxygen at a significantly greater rate than did control embryos of the same age. The Qo2 for the abnormally developing embryos returned to the control value 24 hours after maternal treatment was terminated. During the period of vitamin deficiency the dry and wet weights of the experimental embryos were less than those of the controls. Subsequent to the deficiency period these attributes gradually returned to control levels.Changes in the oxygen consumption of experimental embryonic preparations were related to the embryo itself and not to the surrounding extraembryonic membranes.
Effect of phenobarbital and SKF 525‐A on the teratogenicity of cyclophosphamide in mice
Authors: Gibson James E. , Becker Bernard A. 
Published: June 2005

AbstractMaternal nontoxic dosages of cyclophosphamide are teratogenic in Swiss‐Webster mice. Phenobarbital induces and SKF 525‐A inhibits liver drug‐metabolizing enzymes in mice. The purpose of this study was to evaluate the effect of SKF 525‐A and phenobarbital on the teratogenicity and development of alkylating activity after cyclophosphamide. Mice were pretreated intraperitoneally with SKF 525‐A (32 mg/kg) or phenobarbital (50 or 100 mg/kg) on days 8, 9, and 10 of gestation. Cyclophosphamide (20 mg/kg, ip) was administered to all groups on day 10. Phenobarbital and SKF 525‐A were not teratogenic. Cyclophosphamide significantly (P < 0.05) reduced the weight of fetuses examined on day 18 of gestation (control, 1.52 vs 0.89 g). SKF 525‐A pretreatment on days 8, 9, and 10 significantly reduced fetal weight from cyclophosphamide (0.79 vs 0.89 g). Phenobarbital pretreatment significantly reversed cyclophosphamide weight effect (1.23 vs. 0.89 g). SKF 525‐A significantly increased the incidence of resorptions, open eyes, polydactyly, aphakia, hydronephrosis, absence or nonossification of ribs, bone fusion. and bone curvature. Phenobarbital abolished cyclophosphamide‐induced limb defects, hydrocephalus, exencephaly, cleft palate, aphakia, and hydronephrosis. Phenobarbital did not affect cyclophosphamide‐induced polydactyly or open eyes. Phenobarbital pretreatment increased and SKF 525‐A pretreatment decreased the concentration of nitrobenzyl pyridine alkylating product of cyclophosphamide (100 mg/kg) in plasma. The teratogenicity of cyclophosphamide may be separate from its alkylating activity.
Microscopic studies of achondroplastic rabbit cartilage
Authors: Shepard Thomas H. , Fry Louis R. , Moffett Benjamin C. 
Published: June 2005

AbstractThe cartilage of long bones in newborn achondroplastic (ac/ac) dwarf rabbits was compared with that of phenotypically normal littermates using histologic, histochemical, and electron‐microscopic procedures. The dwarf cartilages contained (1) dead chondrocytes (nuclear pyknosis and absence of surrounding moat) distributed with increasing frequency from the periphery to the center of the resting cartilage (littermate controls showed far fewer and a random distribution of dead chondrocytes); (2) fewer chondrocytes in the isogenous groups or capsules of central portion of the metaphyseal growth plate compared to controls; and (3) less cartilage matrix. Based on these observations it is suggested that a metabolic defect may become expressed specifically in achondroplastic cartilage cells when they are isolated from their vascular supply.
The effects of teratogenic doses of hypoxia on the blood pressure of chick embryos
Authors: Grabowski Casimer T. , Tsai Enoch N. C. , Toben Howard R. 
Published: June 2005

AbstractExposure of chick embryos to moderate hypoxia (6–10% O2 for 4–6 hours) induces a marked blood‐volume increase. This treatment also precipitates hemorrhage that can cause death or malformation or both when localized near rapidly developing structures. To determine whether the hypoxia‐induced hypervolemia can raise embryonic blood pressure to a hemorrhage level, the mean ventricular blood pressure (MVBP) of 587 embryos was measured before, during, and after treatment. The mean MVBP of 3‐day embryos rose from 11.1 mm water to 14.7 mm during the first two hours of hypoxia, dropped slowly during the rest of treatment, then increased again after exposure to air. The highest mean values (16.4 mm) were obtained two hours after treatment, coinciding with the time of maximum hemorrhage. The range of MVBP at that time was wide (6.0–27.0 mm) and in many embryos was twice as high as normal. The MVBP gradually returned to normal 2–13 hours after treatment. Maximum increases in the MVBP of 4 to 5‐day embryos also occurred during the second hour after treatment, but recovery after that was faster than at three days.In a parallel experiment hypervolemia was induced by sequential injection of saline into the ventricles of 3‐day embryos, in between pressure measurements. The MVBP rose slowly up to 30 mm water. Bleeding usually began at pressures of 18 mm. Hypervolemia induced by hypoxia appears to be responsible for the blood‐pressure increases and the development of teratogenically important hemorrhage.
Serum proteins and disazo dye teratogenesis
Authors: Beaudoin Allan R. 
Published: June 2005

AbstractSerum proteins of pregnant rats were analyzed by paper electrophoresis following administration of the teratogenic disazo dyes trypan blue, Evans blue, Niagara blue 4B, Niagara sky blue 6B, Congo red, and Niagara blue 2B. Sera were obtained from blood taken by cardiac puncture just before dye injection, 48 hours after dye injection; and again at autopsy. All of the dyes tested caused a reduction in serum albumin and total protein concentration and an elevation in the concentration of beta or alpha‐2 globulins at some time during pregnancy. The remaining serum fractions reacted variably to the dye treatment. In spite of the rather consistent results presented in this paper, and similar findings reported for other teratogens, there is no direct proof that altered serum proteins, per se, are causally related to the production of malformations.
Response of the lateral motor column to multiple forelimbs in Rana pipiens
Authors: Pollack Emanuel D. 
Published: June 2005

AbstractThe lateral motor columns of a recently metamorphosed frog (Rana pipiens) that had three functional forelimbs on the left side were analyzed for differences on the two sides of the spinal cord. It was found that there was no gross hyperplasia on the left side, nor were there significant differences between the mean nuclear areas of the cells of the two sides. Significant differences did occur, however, in the distribution of nuclear sizes of the two sides. A greater proportion of the cells of the left side had large nuclear areas than did those of the right side. This points to a response of the lateral motor column to an increased periphery by increasing sizes of certain cells rather than by increasing cell numbers.
Fetal weight and intrauterine position in rats
Authors: Barr Mason , Jensh Ronald P. , Brent Robert L. 
Published: June 2005

AbstractFetal weight data from 28 litters of Wistar rats were analyzed for the effect of position in the uterine horn on fetal weight. The deviation of each fetus from the mean weight of all fetuses in a uterine horn was divided by the standard deviation of the mean. The standard scores thus obtained were studied for position effect. A pattern of fetal weights was found in which the heaviest fetus occupied the middle position with a progressive decrease in weights toward the ovarian and cervical ends of the horn. The lightest fetus in each horn was most likely to be found occupying either one of these extreme positions. These results are discussed with respect to a hemodynamic theory of fetal growth control that has been postulated for the guinea pig and mouse, and it is concluded that this theory is not applicable to the normal rat pregnancy.
Effects of ovariectomy and hypervitaminosis A on lysosomes of the rat conceptus
Authors: Schultz Richard L. 
Published: June 2005

AbstractThis report is concerned with some biochemical effects of ovariectomy and hypervitaminosis A on cell organelles, with particular emphasis on the lysosomes, of embryos, yolk sacs, and placental labyrinths of 13‐day pregnant rats. The two parameters considered were lysosomal stability and the distribution of enzymes in fractions obtained by differential centrifugation. Lysosomal stability was determined by measuring (1) the amount of “free” enzyme activity, i.e., the amount of enzyme in the cytoplasmic extracts of the three tissues measured in the presence of isotonic sucrose and (2) the amount of “nonsedimentable” enzyme. Excess vitamin A produced no change in the latency of acid phosphatase or β‐glucuronidase in any of the tissues when compared with controls. Following ovariectomy there was marked labilization of both enzymes in embryos, increased labilization of β‐glucuronidase in placentas, and little change in yolk sacs.The distributions of the lysosomal enzymes in control fractions were not the same in the three tissues, indicating differences in size, shape, and/or density of the lysosomes. There was no change in the distribution of reference enzymes after hypervitaminosis A. Ovariectomy produced increased solubilization of β‐glucuronidase in the three tissues and a lesser increase in soluble acid phosphatase in embryos, indicating lack of uniformity in the lysosomes.
The relation of sex‐associated facial profile reversal and stages of human palatal closure
Authors: Burdi Alphonse R. , Silvey Ralph G. 
Published: June 2005

AbstractThis report is concerned primarily with the chronological relations among stages of palatal closure, changes in facial profile, and the sex of a select group of human embryos representing the critical period of palate development. Histological serial sections of 40 human embryos ranging in age from 6 to 9 weeks and free from gross defects were studied using light microscopy and graphic reconstructions. Maxillary prognathism usually occurred concomitantly with vertically oriented palatal shelves. As the shelves progressively assumed a horizontal position prior to palatal closure, a profile reversal occurred, i.e., the lower jaw became prognathic. Both profile reversal and reorientation of the palatal shelves occurred earlier in males (seventh week) than females (eighth week). These patterns suggest a sexual dimorphism in which the palatal shelves in females are apart and vertical for a relatively longer time than in males. Also, the concordance between palatal‐shelf elevation and mandibular prognathism suggests that the forward repositioning of the lower jaw may contribute to the removal of the tongue from between the palatal shelves.
Relation of dosage and time of administration of diphenylhydantoin to its teratogenic effect in mice
Authors: Harbison Raymond D. , Becker Bernard A. 
Published: June 2005

AbstractDiphenylhydantoin was teratogenic and caused prenatal death in Swiss‐Webster mice. Most deaths resulted after single treatment on days 10, 11, 12, 14, and 15. Fetal body weight was significantly reduced in a dose‐related manner after single treatment on days 9 to 15. Single injections of diphenylhydantoin produced open eye, ectrodactyly, cleft lip, cleft palate, hydronephrosis, and internal hydrocephalus. Skeletal defects noted were incomplete ossification of sternebrae or cervical centra, unfused sternebrae, and fused vertebrae. Long bones were shortened in a day‐ and dosage‐dependent fashion. Mortality, teratogenesis, and effect on fetal growth were day‐ and dosage‐dependent as was the spectrum of anomalies produced.