Developmental Toxicity of Aspirin Prenatally Given to Rats: Assessment in Sic: Wistar-KY Rats

Abstract Slc:Wistar-KY rats were administered orally with 62.5, 125, 187.5 or 250 mg/kg aspirin suspended with 0.5 % CMC-Na on days 9–11 of gestation (plug += day 0). Suppression of maternal weight gain and food consumption during treatment was observed at and over 187.5 mg/kg. At term, the fetal mortality increased at and over 187.5 mg/kg and the fetal weight was lowered at and over 125 mg/kg. Among 15 live fetuses at 250 mg/kg, 4 had external malformations. In the skeletal examination (double staining), skeletal anomalies increased at and over 187.5 mg/kg. The skeletal variations such as vertebral anomalies, fused costal cartilages and increased presacral vertebrae were often encountered and delayed ossification was also found at and over 125 mg/kg. The internal anomalies tended to increase at and over 187.5 mg/kg. The live birth rate was significantly lower at 187.5 mg/kg than that in controls, and all pups, except for 3 from a dam, died before weaning. At 125 mg/kg, the pivoting locomotion on day 7 post partum was poorer as compared with controls. The physical and functional development at 62.5 mg/kg was not changed. There were no significant effects on male offspring in the open-field, rotarod, under-water T-maze and avoidance learning tests. However, in the Biel T-maze test (9–10 weeks of age), the aspirin-treated groups showed more errors and the increased elapsed time on the 1st trial day than controls. These results indicate that aspirin may induce a slight learning defect on rat offspring even at the non-teratogenic dose and the Biel T-maze test is more sensitive than any other learning tests given in this study.     

Developmental Toxicity of Aspirin Prenatally Given to Rats: Assessment in Slc: Wistar-KY Rats

ABSTRACT  Slc:Wistar-KY rats were administered orally with 62.5, 125, 187.5 or 250mg/kg aspirin suspended with 0.5 % CMC-Na on days 9–11 of gestation (plug += day 0). Suppression of maternal weight gain and food consumption during treatment was observed at and over 187.5 mg/kg. At term, the fetal mortality increased at and over 187.5 mg/kg and the fetal weight was lowered at and over 125 mg/kg. Among 15 live fetuses at 250 mg/kg, 4 had external malformations. In the skeletal examination (double staining), skeletal anomalies increased at and over 187.5 mg/kg. The skeletal variations such as vertebral anomalies, fused costal cartilages and increased presacral vertebrae were often encountered and delayed ossification was also found at and over 125 mg/kg. The internal anomalies tended to increase at and over 187.5 mg/kg. The live birth rate was significantly lower at 187.5 mg/kg than that in controls, and all pups, except for 3 from a dam, died before weaning. At 125 mg/kg, the pivoting locomotion on day 7 post partum was poorer as compared with controls. The physical and functional development at 62.5 mg/kg was not changed. There were no significant effects on male offspring in the open-field, rotarod, under-water T-maze and avoidance learning tests. However, in the Biel T-maze test (9–10 weeks of age), the aspirin-treated groups showed more errors and the increased elapsed time on the 1st trial day than controls. These results indicate that aspirin may induce a slight learning defect on rat offspring even at the non-teratogenic dose and the Biel T-maze test is more sensitive than any other learning tests given in this study.     

In Vitro Developmental Toxicity of Aspirin and Its Major Metabolites on Cultured Fetal Mouse Palates

Palatal primordia of day-12.5 ICR mouse fetuses were cultured in a chemically-defined serumless medium by a suspension culture technique, and the developmental toxicity of aspirin and its metabolites on in vitro palatogenesis was studied. Explanted fetal palates were exposed in vitro for 72 hr to 0.5-2 mM aspirin (ASP), 0.25-2 mM salicylic acid (SA), 0.5-2 mM salicyluric acid (SUA), 1–2 mM 2,3-dihydroxybenzoic acid (3DHB), or 1–2 mM 2,5-dihydroxybenzoic acid (5DHB). After 72 hr culture, ASP at 2 mM and SA at 0.25 mM inhibited the growth and fusion of palatal shelves, and SUA at 1 mM prevented palatal fusion. On the other hand, 3DHB and 5DHB did not exert any significant toxic effects on cultured palates at concentrations up to 2 mM. Judging from the 50% inhibitory concentration (IC₅₀), SA (IC₅₀= 0.9 mM) was the most toxic of the 5 compounds tested, with a decreasing order of ASP (IC₅₀= 1.5 mM), SUA (IC₅₀= 1.6 mM), and DHBs (IC₅₀= over 2 mM for both 3DHB and 5DHB). With respect to developmental toxicity, cultured fetal mouse palates showed the susceptibility to aspirin and its metabolites which is intermediate between the susceptibility of rat embryos in vivo and that of postimplantation rat embryos cultured in vitro. The significance of fetal organ culture for evaluating developmental toxicity of chemicals is also discussed.     

Collaborative Behavioral Teratology Study of Phenytoin: A Test Battery for Neurobehavioral Developmental Toxicity in Rats.

Abstract: At the Behavioral Teratology Meeting (BTM) of the Japanese Teratology Society in 1992, a core test battery was proposed from a practical and simple point of view as an estimation of developmental neurobehavioral toxicity for use in pharmaceutical drug screening. The validity of the core test battery is being examined in a new series of collaborative studies. The present study is the first such study; phenytoin, a well-known behavioral teratogen, was selected as the test compound, and 32 laboratories took part in a behavioral teratology study of phenytoin using the new test battery. Sprague-Dawley strain rats from four breeds were used. Phenytoin (200 mg/kg) was administered orally to pregnant rats from days 10 to 14 of gestation (sperm detection = day 0), and in the male offspring, the survival rate, development of physical landmarks, functional developments, open field test scores, and Biel water maze test results were assessed and the brain weights were measured. The shuttle box conditioned avoidance test was also performed in some laboratories. In the present collaborative study, by taking an aggregate of the relative values converted from the measured values of each breed (providing a much larger sample size than that recommended by reproduction toxicity study guidelines), a high detectability level for phenytoin's effects was established. Under these conditions, the effects of phenytoin on eye opening, incisor eruption, the surface righting reflex, the negative geotaxis reflex, and performance of the open field test, Biel water maze test and shuttle box conditioned avoidance test were observed. It was found that present collaborative study made it possible to evaluate the detectable capacity of each of these test battery items. In addition, the critical period of abnormalities demonstrated in many test items was identified, and the results of several previous reports were confirmed. Furthermore, a breed difference in the effect of phenytoin for several test items was found. The present results established that the core test battery accurately detected the effects of phenytoin.     

Behavioral Testing in the Context of Reproductive and Developmental Toxicity Screening in the West*

Abstract Methods for assessing animal neurobehavior following prenatal/perinatal exposures have been in use for almost 20 years and screening tests incorporating them are regulated in three settings: in Japanese Segment II and III studies on drugs, European (EEC/UK) Segment I studies on drugs, and American neurotoxicity studies on chemicals. The methods used in the West for assessing behavior in these contexts at present are described in detail. The evolution of the methods over time, the concepts of apical tests and functional domains, the use of positive control agents, what the U.S. Collaborative Study has shown us, and justification for assessing animal behavior in predicting outcome from human exposures are discussed.     

Developmental Progression of Motor Skills in Children Prenatally Exposed to Cocaine

This study tested the motor development of 73 infants who were prenatally exposed to cocaine using the Peabody Developmental Motor Scales at 6, 12, 18, and 24 months of age. Repeated measures MANOVA found a main effect for age with scores decreasing as children increased in age. The significant interactive effect between age and skill type indicated that fine motor quotient scores decreased more than the comparable gross motor scores. T-tests showed significant differences between the two skill types: fine motor skills were higher at the first two testing periods and lower at the last two periods. This article discusses the nature of the delays at specified age periods and the implications for future assessment and programming.     

Vasoactive Intestinal Polypeptide-containing Neurons and Processes in the Developing Hippocampus of Rats Prenatally Exposed to Methylazoxymethanol Acetate

Developmental alteration of the dendritic arborization and axonal boutons of vasoactive intestinal polypeptide (VIP) neurons in the CA1 hippocampus was immunohistochemically examined in both control and microcephalic rats at postnatal days 15 and 60. Microcephaly was induced by prenatal exposure to methylazoxymethanol acetate (MAM; 20 mg/kg) on day 15 of gestation (MAM rats). In the control at postnatal day 15, VIP-immunoreactive axonal boutons were densely aggregated specifically in the stratum pyramidale. At postnatal day 60, these axonal boutons in the stratum pyramidale of the controls were somewhat less dense. Another aggregation of axonal boutons was also observed along the upper part of the stratum oriens near the alveus border (area A). In the MAM rats at postnatal day 15, on the other hand, VIP-immunoreactive neurons in the CA1 hippocampus were decreased in number and the dendritic arborization of these neurons was very poor compared with the controls. The density of VIP-immunoreactive axonal boutons was remarkably lower than the controls. In the MAM-rats at postnatal day 60, density of the axonal boutons was almost similar with that of MAM-rats at postnatal day 15 in the stratum pyramidale, whereas a drastic increase was observed in area A, which made the bouton aggregation more dense than in the controls at postnatal day 60. These observations suggest that there is an area-dependent difference in the development of VIP neurons in the CA1 hippocampus which may be related to the area-dependent heterogeneous vulnerability of VIP neurons to MAM exposure.     

Species Difference in Developmental Toxicity of an N-Phenylimide Herbicide between Rats and Rabbits and Sensitive Period of the Toxicity to Rat Embryos

An N-phenylimide herbicide, S-53482, exhibited developmental toxicity in rats in the absence of maternal toxicity at a dose of 30 mg/kg. The developmental toxicities noted were embryolethality, teratogenicity (mainly ventricular septal defect [VSD] and wavy ribs) and growth retardation. In contrast to rats, the herbicide showed no developmental toxicity in rabbits even at a maternal toxic dose of 3,000 mg/kg. There was a remarkable species difference between rats and rabbits. A single dose of S-53482 was administered to pregnant rats on one of gestation days 11 through 15 (detection of plug = day 0). Day 12 of gestation was the most sensitive day for embryonic death, VSD, and decreased fetal body weight. It is likely that there is a common mechanism for the three types of developmental toxicity and that S-53482 does not produce VSD by its direct damage to embryonic heart tissue.     

Multidisciplinary Assessment of Children with Developmental Coordination Disorder: Using the ICF Framework to Inform Assessment

The aim of this study was to describe relationships in young children with motor coordination problems between measures of motor, functional, self-efficacy, and communication administered by a multidisciplinary team and the fit of these measures within the framework of the International Classification of Functioning, Disability and Health (ICF) (). Sixty children, 40 males and 20 females, with mean age 72.5 months (SD = 11.4 months) referred to a university physiotherapy clinic met the inclusion criteria for developmental coordination disorder (DCD). Each measure provided a different perspective of performance when considered within the framework of the ICF. The findings suggest caution when using the Movement Assessment Battery for Children (M-ABC) for the purpose of diagnosis with young referred children, since 25 of the 60 children scored > 15th percentile, despite demonstrating motor deficits at home and school. Further research is needed to address assessment at the participation level. Viewing children from the multiple perspective of each discipline highlights the range of challenges faced by children with DCD.     

Male-Mediated Developmental Toxicity: Enhanced Susceptibility to Induced Teratogenesis in the Offspring of Male Mice Treated with Ethylnitrosourea

Male ICR strain mice were injected intraperitoneally with ENU at 50 mg/kg daily for 5 days and mated to untreated virgin females of the same strain on days 64–80 after the last dose. Copulations during this period involved spermatogonial stem cells at the time of the last treatment. Subsequently, copulated females were injected intraperitoneally with ENU at 25–100 mg/kg on day 8 of gestation, at 50–200 mg/kg on day 12 of gestation or injected subcutaneously with triamcinolone acetonide at 1.25–10 mg/kg on day 12 of gestation. The uterine contents were examined on day 18 of gestation. Fetuses of dams treated on day 8 of gestation were inspected for external and skeletal abnormalities, and those of dams treated on day 12 were inspected for external abnormalities including cleft palate. Frequencies of microphthalmia and cleft palate in the group in which females mated with ENU-treated males were treated with ENU at 50 mg/kg on day 8 of gestation or with ENU at 50 mg/kg on day 12 of gestation, respectively, were significantly higher than those in the group in which females mated with phosphate buffer-treated males were treated with ENU at 50 mg/kg on day 8 or at 50 mg/kg on day 12. No significant increases in the frequency of cleft palate were observed in the groups in which females mated with ENU-treated males were treated with triamcinolone acetonide on day 12 of gestation as compared with groups in which females mated with phosphate buffer-treated males were treated with triamcinolone acetonide on day 12 of gestation. These results suggested the increased susceptibility to induced teratogenesis (congenital malformations induced by exposure of embryo/fetus during gestation) in the offspring derived from paternal germ cells treated with the potent mutagen ENU, but not the non-mutagen triamcinolone acetonide.     

Developmental Defects of Teeth in Survivors of Childhood ALL Are Related to the Therapy and Age at Diagnosis

The relation of the therapy used and age at diagnosis to developmental defects of dental enamel and root was analyzed in 45 survivors of childhood acute lymphoblastic leukemia (ALL) and compared to that of age-and sex-matched healthy controls. Chemotherapy alone increased the number of enamel defects, but it did not affect the roots. The scattered irradiation of 0.72–1.44 Gy to the dental arches during central nervous system (CNS) irradiation caused an increased number of developmental defects both in enamel and root. Age at diagnosis is an important factor and it showed that the irradiation of 10 Gy did not cause enamel defects if amelogenesis was complete. In conclusion, the therapy is related to developmental defects of the teeth but the most important factor is age, both at diagnosis and during the therapy. © 1995 Wi1ey-Liss, Inc.     

Japan Pharmaceutical Manufacturers Association (JPMA) Survey on Background Control Data of Developmental and Reproductive Toxicity Studies in Rats, Rabbits and Mice

ABSTRACT The Non-Clinical Evaluation Subcommittee of the Drug Evaluation Committee, Japan Pharmaceutical Manufacturers Association (JPMA) collected historical control data from developmental and reproductive toxicity studies, which were conducted by the member companies and associated contract laboratories between 1986 and 1993. The data include spontaneous incidences of fetal morphological alterations and other observations made at terminal cesarean sections in rats, rabbits and mice. In addition, mating and natural delivery data in rats are also provided. There were strain differences as well as inter-laboratory variations in the incidences of fetal visceral and skeletal alterations for both rats and rabbits. These inter-laboratory variations were attributed to differences in the selection of observation parameters, observation criteria and classification of the findings.     

癫(癎)持续状态对发育期大鼠学习记忆及海马磷酸化的c-AMP反应元件结合蛋白表达的影响

目的探讨癫癎持续状态(SE)对发育期大鼠学习记忆功能及海马磷酸化的c-AMP反应元件结合蛋白(pCREB)表达的影响。方法6周龄SD大鼠32只随机分为SE组和9g/L盐水对照组(NS组)。戊四氮(PTZ)诱导发育期大鼠SE。采用Morris水迷宫和Y迷宫观察大鼠学习记忆功能的改变,应用免疫组织化学方法检测大鼠海马各区pCREB的表达。结果与NS组比较,SE组在Morris水迷宫测试中平均逃避潜伏期明显延长(P<0.05),原平台所在象限的游泳时间明显缩短(P<0.05);Y迷宫中达标所需的训练次数显著增多(P<0.05),24h记忆保持率明显降低(P<0.05)。海马CA1区和齿状回(DG)区pCREB表达显著下调(P<0.05)。结论SE可使发育期大鼠学习记忆功能受损,其机制可能与海马pCREB表达减少有关。     

Effects of maternal exposure to thiamazole on behavioral development in infant cynomolgus monkeys

Thiamazole, an anti‐hyperthyroidism agent, was administered orally to pregnant cynomolgus monkeys at doses of 2.0 and 3.5 mg/kg per day from GD 120 to GD 150 to investigate effects on behavioral development of their infants. Swelling of the throat region due to enlargement of the thyroid glands was observed at birth in thiamazole‐treated infants, and it returned to normal around postnatal day (PND) 30. At necropsy of infants at 12 months of age, thyroidal weight in the thiamazole groups was increased. This finding suggested the likelihood that administration of thiamazole to maternal animals during the late gestational period induced thyroid goiter in fetal/infant monkeys through placental transfer of thiamazole. No clear changes were noted in thyroid histopathology or serum thyroid hormone levels in maternal animals or infants, but goiter formation might have been indicative of exposure to high thyroid stimulating hormone (TSH) and low T3 or T4 in utero from maternal treatment with thiamazole. Age‐related changes were observed in the control in behavioral development tests, while infants at 3.5 mg/kg showed no age‐related decrease in contact behavior and no increase in exploratory activity on PND 90 or PND 170. In addition, the number of eye contacts between PND 210 and PND 240 was less frequent. This indicated that maternal exposure to thiamazole induced mental retardation‐like behaviors in infants. Thiamazole may directly inhibit thyroid hormone synthesis in the fetus by placental transfer. From these results, it was speculated that oral administration of thiamazole to maternal animals during the late gestational period induced retardation of behavioral development in their infants.     

A Developmental Study of Reflex and Activity in Rats with Microcephaly Induced by Prenatal Methylazoxymethanol Acetate (MAM) Treatment

Pregnant Wistar rats were given a single i. p. injection of 30 mg/kg methylazoxymethanol (MAM) acetate or saline on day 13 of pregnancy (vaginal plug = day 0). All offspring were subjected to reflex tests during the preweaning period (surface righting reflex, from 3 to 12 days of age; negative geotaxis reflex, from 5 to 12 days of age), and then selected male rats were subjected to open-field test during the postweaning period (from 21 to 35 days of age). The MAM-treated rats showed significantly longer latencies in the both reflex tests, and also significant hyperactivity in the open-field test. These behavioral alterations were analyzed in relation to the large size reduction in the cerebral cortex and the morphological abnormalities of the hippocampus in the MAM-treated rats.     

HEDEN Pain Scale: A Shortened Behavioral Scale for Assessment of Prolonged Cancer or Postsurgical Pain in Children Aged 2 to 6 Years

Few observational scales are available for assessing chronic or recurrent pain in children with cancer because overt behavioral signs of chronic pain dissipate as time passes, making them difficult to detect reliably. The Douleur Enfant Gustave Roussy (DEGR) scale developed by Gauvain-Piquard to monitor prolonged pain in children with cancer aged 2–6 years is currently the only validated tool available for this purpose, but is time consuming and difficult to use in daily clinical practice. To shorten composite measurement scales, we developed the Hétero Evaluation Douleur Enfant (HEDEN) scale from the DEGR scale. We present here the process and validation of this scale. Expert consensus was used for the elaboration of HEDEN: 5/10 DEGR items were chosen with three rating levels. Concurrent validity was tested in a first cohort with correlation analysis between HEDEN and DEGR. The HEDEN scale was then validated in a second cohort. In the first step, the study (59 children) showed acceptable correlation between DEGR and HEDEN (r = 0.5), with good reliability (α = 0.61), and interrater agreement (r = 0.62). Subsequent validation in 48 children showed a significant correlation between DEGR and HEDEN (r = 0.6). Reliability was good (α = 0.75), with excellent interrater agreement [r = 0.67 (95% CI: 0.48–0.79)]. On average, the evaluation took 23 minutes (SD = 10.4) for DEGR versus 4.42 minutes (SD = 5.9) for HEDEN. This study shows a good correlation between HEDEN and DEGR scales. HEDEN allows accurate assessment of prolonged pain in young children with cancer.     

Practitioner Review: Communicating with Hospitalised Children: Review and Application of Research Pertaining to Children's Understanding of Health and Illness

There is growing recognition amongst child health care practitioners of children's rights to be informed about their condition and treatment, and to be actively involved in decisions pertaining to their care. In order to facilitate such understanding, there is a need to explore the ways in which such concepts can best be communicated, in particular to younger children whose conceptual ability may be regarded as limited. Consideration of the literature on how children's conceptualisation of health and illness develops reveals diverse perspectives, with seminal work heavily influenced by the work of Piaget (1929), and a belief that the understanding of younger children may be minimal. However, more contemporary theorists refute such beliefs, suggesting that children may have far more potential to understand complex illness concepts than they have previously been given credit for. The work of Carey (1985) and Vygotsky (1962) offers alternative developmental theories congruent with this perspective, which might more appropriately underpin current practice. A variety of clinical situations are then explored in the light of this debate, including preparation of children for hospitalisation, their competence to consent, their views of pain and death, and approaches to child health promotion. Guidelines are offered to practitioners throughout, with the aim of enhancing children's understanding of their conditions, and their active participation in care, which in turn has the potential to optimise care delivery.