Niemann-Pick disease: coupling and uncoupling of inhibited sphingomyelinase activity and exogenous cholesterol esterification in fibroblasts by ionophore treatment

In order to elucidate a biochemical relationship between sphingomyelin and cholesterol metabolisms, we examined the effects of several ionophores (monensin, nigericin, A23187, ionomycin, lasalocid) on sphingomyelinase activity and cholesterol esterification in cultured human fibroblasts. Phase-contrast microscopy showed the presence of foamy cells with monensin and nigericin treatments only. Electron microscopic examination revealed lamellated membranous bodies and cytoplasmic vacuoles in cells treated with monensin and nigericin. Monensin and nigericin treatments led to reduction of acid sphingomyelinase activity and disturbance of the esterification of lipoprotein-derived cholesterol in cultured fibroblasts, which is compatible with the biochemical changes of Niemann-Pick disease, type C. A23187, ionomycin, and lasalocid treatments showed only sphingomyelinase reduction in treated fibroblasts. Experimental models in this culture system could be produced in these ways, mimicking subtypes of Niemann-Pick disease, type A, B and type C.

Epidemiology of limb-body wall complex in Japan

Limb-body wall complex is a malformation of body and limbs with craniofacial defects. We describe here the epidemiology of this complex using the population-based registry data in the Kanagawa Birth Defects Monitoring Program during the period 1982-1991. Eleven infants (11/428,599 births) with the complex were ascertained in the study. The incidence and spectrum of the defects observed in our cases were similar to those of other studies. The parental ages in the study group were not significantly different from those in the general population. No teratogenic agents and factors were identified in the present study. Most cases were diagnosed prenatally.

Apoptotic degeneration in the arhinencephalic brain of the mouse mutant Pdn/Pdn

The homozygotes of a mouse strain with genetic polydactyly (Polydactyly Nagoya, Pdn) exhibit arhinencephaly and various brain malformations. In the present experiment, abnormal apoptotic degeneration in the arhinencephalic brain of Pdn/Pdn embryos and newborns was investigated immunohistochemically and by molecular genetic techniques. Polyclonal antibody against single-stranded DNA detected the nuclei of programmed dying cells (apoptotic cells) specifically in the interdigital necrotic zone of the normal mouse limb plate on day 14 of gestation. We used this antibody against single-stranded DNA to investigate the apoptotic degeneration in Pdn/Pdn brain. Abnormal apoptosis was observed in the infralimbic cortical plate, hypothalamus and periventricular thalamus on day 0 after birth in Pdn/Pdn brains. The TRPM-2 gene, which has been considered to mediate apoptosis, was expressed in the developing normal and Pdn/Pdn brains. TRPM-2 gene expressions in the brain stem and cerebellum of arhinencephalic Pdn/Pdn fetuses and newborns were higher than those of +/+ littermates. From these facts, it was suggested that the abnormal apoptosis caused a large amount of cell loss in the arhinencephalic mouse brain, and this cell loss induced the expansion of the ventricle, followed by the hydrocephaly.

Role of 5 alpha-reductase in health and disease

The mechanism of androgen action varies in different tissues, but in the majority of androgen target tissues either testosterone or 5 alpha-dihydrotestosterone (DHT) binds to a specific androgen receptor to form a complex that can regulate gene expression. Testosterone is metabolized to DHT by the enzyme 5 alpha-reductase. The autosomal recessive genetic disorder of 5 alpha-reductase deficiency has clearly shown that the requirement for DHT formation varies with different tissues. In this syndrome genetic males contain normal male internal structures including testes, but exhibit ambiguous or female external genitalia at birth; at puberty they undergo partial virilization which includes development of a male gender identity even if brought up as females. Their development suggests that testosterone itself is able to stimulate psychosexual behaviour, development of the embryonic wolffian duct, muscle development, voice deepening, spermatogenesis, and axillary and pubic hair growth; DHT seems to be essential for prostate development and growth, the development of the external genitalia and male patterns of facial and body hair growth or male-pattern baldness. How different hormones operate to regulate genes via the same receptor is currently unknown, but appears to involve cell-specific factors. The 5-alpha-reductase enzyme has proved difficult to isolate biochemically, but recently at least two human isoenzymes have been identified using molecular biological methods. All the various 5 alpha-reductase-deficient kindreds have been shown to have mutations in 5 alpha-reductase 2, the predominant form in the prostate. The biological role of 5 alpha-reductase 1 has not yet been ascertained, but at present it cannot be ruled out that some of the actions ascribed to testosterone are indeed in cells producing DHT via this enzyme. The activity of 5 alpha-reductase is also implicated in benign prostatic hypertrophy, hirsutism and possibly male-pattern baldness; recent evidence discounts the role of 5 alpha reductase 2 in sebaceous glands and acne. Specific inhibitors of both enzymes are now available and finasteride, a 5 alpha-reductase 2 inhibitor, has been used successfully in clinical trials of benign prostatic hypertrophy. Knowledge of 5 alpha-reductase is expanding dramatically at the moment with the application of molecular biological methods. The advent of antibodies to the isoenzymes should herald further understanding of their biological and clinical roles.

Induction of chromosome aberrations by pyrimethamine in cultured Chinese hamster (CHL) cells

Induction of chromosome aberrations was investigated in cultured Chinese hamster cells treated with pyrimethamine. Pyrimethamine without metabolic activation strongly induced structural chromosome aberrations in a dose-dependent manner. Aberrant metaphase cells occurred at a frequency of 80%, when cells were treated at 1.6 microgram/ml for 48 h.

Klippel-Feil syndrome associated with malformed larynx. Case report

We report a case of a 45-year-old man with Klippel-Feil syndrome with fusion of the C2-3 and C4-5 cervical vertebrae and severe voice impairment associated with malformation of the laryngeal cartilages. The condition was also complicated by bilateral inflexibility of the arms and legs and external malformation of the ears. This case broadens the spectrum of anomalies, of branchial arch derivation, now identified in association with Klippel-Feil syndrome. We discuss the possibility that perturbation of segmentation, distinct from somitogenesis, may be linked to Klippel-Feil syndrome-associated craniofacial abnormalities.

Characterization of the developmental toxicity of di-n-butyl phthalate in rats

The objective of this study was to determine the characterization of the developmental toxicity of di-n-butyl phthalate (DBP) in rats. Pregnant rats were given DBP by gastric intubation at a dose of 0.75, 1.0 or 1.5 g/kg on days 7-9, 10-12 or 13-15 of pregnancy. Postimplantation loss was 100% for each period of dosing at 1.5 g/kg. A significant increase in the postimplantation loss was found in dams given DBP at doses of 0.75 and 1.0 g/kg regardless of the days of treatment. No evidence of teratogenicity was detected when DBP was given on days 10-12. Treatment on days 7-9 with DBP at doses of 0.75 and 1.0 g/kg caused a significant increase in the number of skeletal malformations such as deformity of the vertebral column in the cervical and thoracic regions and of the ribs, but neither external nor internal malformations. Treatment with DBP on days 13-15 at doses of 0.75 and 1.0 g/kg resulted in a significant increase in the incidence of fetuses with external and skeletal malformations such as cleft palate and fusion of the sternebrae. The frequency of malformations increased as the dose of DBP was increased. The highest incidence of malformed fetuses occurred after treatment with DBP on days 13-15. It could be concluded that susceptibility to the teratogenicity of DBP varies with the developmental stage at the time of administration.

Pathogenesis of cerebellar deformity in experimental Chiari type I malformation caused by mumps virus

We sought to elucidate the pathogenesis of Chiari type I malformation using an experimental model of hydrocephalus produced by inoculating hamsters with mumps virus. Dilatation of the lateral ventricules was detected in all brains inoculated at 2, 10, and 25 days of age. The cerebellum in hamsters inoculated at 2 and 10 days of age showed elongation and flattening of the vermis and protrusion or notching of the uvula. All layers, i.e., the molecular, Purkinje cell, and granular layers, and the white matter were preserved, but had become narrow. Purkinje cells remained normal. Hamsters inoculated at 25 days of age did not develop the cerebellar deformity. Mumps virus antigen was detected in all ependymal cells and in some epithelial cells of the choroid plexus in all hamsters that had been inoculated at 2, 10, or 25 days of age. Results suggest that Chiari type I malformation is caused by two main factors occurring simultaneously, i.e., increasing intracranial pressure and rapid histogenesis of the cerebellar cortex.

Comparison of four spatial maze learning tests with methylnitrosourea-induced microcephaly rats

The usefulness of four spatial maze learning test methods, single T-maze, Biel water maze, Morris water maze, and radial eight-arm maze, was compared using rats with different degrees of microcephaly, which were induced by single intraperitoneal injection with 3 and 5 mg/kg of methylnitrosourea (MNU) on day 13 of gestation. The single T-maze test did not detect a learning defect in either MNU group. In the Biel water maze test, the swimming time and number of errors were increased in the 5 mg/kg group, but these parameters were comparable to the control values in the retention and path B (reverse course) tests. On the Morris water maze task, the 5 mg/kg group required longer swimming time and distance to reach the goal. In the retest with the goal set on an opposite side, the swimming distance in the 5 mg/kg group was as long as the value in the original test. The radial eight-arm maze test detected fewer correct choices in both MNU groups, which showed different responses on this task. The brain weights in the 3 and 5 mg/kg groups were approximately 80 and 60% of the control value, respectively. The cerebral cortex weights were 77 and 50% of the control value, and the hippocampus weights were 78 and 51%. Among the four maze tests, only the radial eight-arm maze test could detect the effect of both doses of MNU. This shows that the method has the highest sensitivity to spatial learning defect in MNU-induced microcephalic rats.

Membrane structure of parallel-fibre synaptic terminals in the cerebellum of the jaundiced Gunn rat: freeze-fracture and E-PTA study

Parallel-fibre synaptic membranes were examined by freeze-fracture and ethanolic-phosphotungstic acid methods in the cerebellum of homozygous (j/j) Gunn rats with hereditary jaundice. Parallel-fibre synapses with dendritic spines of Purkinje cell were severely affected since many Purkinje cells degenerated during the early postnatal period. Some parallel-fibre synaptic terminals lacked their postsynaptic partners and faced astrocytic processes from 18 days of age to the adult stage. These parallel-fibre terminals contained clusters of synaptic vesicles adjacent to synaptic membranes, and synaptic membranes and synaptic cleft materials were identical to those of parallel fibres with postsynaptic partners, as visualized by conventional electron microscopy with osmium tetroxide postfixation and staining of sections with uranyl acetate and lead citrate. In freeze-fractured specimens, the presynaptic membrane of parallel fibres had diffusely distributed large particles and tiny pits on the P-face and protuberances on the E-face, together representing synaptic vesicle attachment sites. Such vesicle attachment sites were present on the presynaptic membranes of parallel fibres without postsynaptic partners from day 18 to the adult stage. After ethanolic-phosphotungstic acid staining, parallel-fibre terminals displayed presynaptic dense projections, intercleft materials and postsynaptic thickening, but some parallel fibres lacked postsynaptic thickening. These observations suggest that the presynaptic membrane structure of the parallel fibre is preserved, even in the absence of a postsynaptic partner, in j/j cerebella. A mechanism for persistence of presynaptic membrane structures without postsynaptic partners in j/j cerebella is discussed.

Short rib-polydactyly syndrome and pericentric inversion of chromosome 4

We report on a newborn infant with clinical and radiological manifestations of some type of short rib-polydactyly syndrome who died soon after birth. Chromosomal studies on peripheral blood lymphocytes and chondrocytes demonstrated an apparently balanced pericentric inversion of chromosome 4 (present in the mother also). This association may have occurred by chance but, if not, the chromosomal breakpoints could interrupt the gene responsible for short rib-polydactyly syndromes, or else be related to the mechanism of short rib-polydactyly syndromes.

Effect of age and sex on copper-induced toxicity in the macular mutant mouse. An animal model for Menkes' kinky-hair disease

It was determined if the sensitivity in macular mutant mouse to copper-induced toxicity was affected by sex or age. The sensitivity in 6-8-d-old or 3-4-wk-old macular mutant mouse to copper-induced toxicity was not affected by sex. However, 8-9-wk-old mutant females were more sensitive to copper-induced toxicity than mutant males. Furthermore, 6-8-d-old or 3-4-wk-old mutant males were more sensitive to copper-induced toxicity than 8-9-wk-old mutant males. However, age-related differences in sensitivity to copper-induced toxicity did not occur significantly in mutant females. On the other hand, in the case of normal mice, the sensitivity in 6-8-d-old or 3-4-wk-old mice to copper-induced toxicity was not also affected by sex. In contrast to mutant, however, 8-9-wk-old normal males were more sensitive to copper-induced toxicity than 8-9-wk-old normal females. Adult males were also more sensitive to copper-induced toxicity than 6-8-d-old or 3-4-wk-old males. However, age-related differences in sensitivity to copper-induced toxicity did not occur significantly in normal females. These results indicate that sex- and age-related differences in the copper-induced toxicity exist in macular mutant mice.

Pathogenesis of craniofacial and body wall malformations induced by ochratoxin A in mice

Ochratoxin A (OA), a mycotoxin commonly found in soils and on moldy food such as cereal grains, is a potent teratogen. The present investigation was designed to examine the teratogenicity of OA administered acutely at early post-implantation stages in mice, with particular emphasis on the pathogenetic basis of induced malformations. Maternal OA administration on gestational day (GD) 7 or 8 resulted in excessive amounts of cell death in selected cell populations. After a single dose of 2-4 mg/kg, excessive cell death was notable within 6 hours, and persisted to 36 hours post-treatment. As observed in GD 14 or 18 fetuses, the spectrum of induced craniofacial malformations included exencephaly, midfacial clefting, cleft lip, as well as hypotelorism, and synophthalmia associated with holoprosencephaly. Body wall defects involved either the abdominal wall alone, or in combination with the thoracic wall, resulting in partial or complete exposure of the viscera. Potential mechanisms for OA-induced selective cell killing are discussed.

Brain fibronectin expression in prenatally irradiated mice

Activation of gene transcription by radiation has been recently demonstrated in vitro. However, little is known on the specificity of these alterations on gene transcription. Prenatal irradiation is a known teratogen that affects the developing mammalian central nervous system (CNS). Altered neuronal migration has been suggested as a mechanism for abnormal development of prenatally irradiated brains. Fibronectin (FN), an extracellular glycoprotein, is essential for neural crest cell migration and neural cell growth. In addition, elevated levels of FN have been found in the extracellular matrix of irradiated lung. To test whether brain FN is affected by radiation, either FN level in insoluble matrix fraction or expression of FN mRNA was examined pre- and postnatally after irradiation. Mice (CD1), at 13 d of gestation (DG), served either as controls or were irradiated with gamma rays at 0.5 or 1 Gy. Control and irradiated animals were killed either at 13 DG, 14 DG, 17 DG, or 5, 6, or 14 d postnatal. Brain and liver were collected from offspring and analyzed for either total FN protein levels or relative mRNAs for FN and tubulin. Results of prenatal irradiation on reduction of postnatal brain weight relative to whole body weight and morphological reduction in cerebral cortex regions of postnatal brains are comparable to that reported by others. Insoluble matrix fraction (IMF) per gram of brain, liver, lung, and heart weight was not significantly different either between control and irradiated groups or between postnatal stages, suggesting that radiation did not affect the IMF. However, total amounts of FN in brain IMF at 17 DG were significantly different (p < .02) between normal (1.66 +/- 0.80 micrograms) and irradiated brains (0.58 +/- 0.22 microgram). FN mRNA was detectable at 13, 14, and 17 DG, but was not detectable at 6 and 14 d postnatal, indicating that FN mRNA is developmentally regulated. After 0.5 Gy of irradiation, expression of FN mRNA was reduced to 36% +/- 22% (1 h), 52% +/- 10% (1 d), and 76% +/- 10% (4 d) of the control level. After 1 Gy of irradiation, relative FN mRNA was 62% +/- 28% (1 h) and 75% +/- 3% (4 days) to the control level, respectively. This reduction was comparable to that reported by others for the cytoskeletal protein beta-actin. In contrast, mRNA for tubulin, another cytoskeletal protein, increased at 1 h after irradiation but then approached normal postnatally. The longer lasting alteration of FN may be more directly related to neural development, particularly if the reduction in FN is nonuniform.

Synergistic embryotoxicity of combination pyrimethamine and folic acid in rats

The increased embryotoxicity of pyrimethamine (PYM) with concomitant oral dosing of folic acid (FA) was examined in rats. The preventive effects of folinic acid (FNA) on PYM embryotoxicity were also examined. Six groups were constructed: PYM I (PYM 1.2 mg/kg/day), FA (FA 50 mg/kg/day), PYM I+FA (1.2 and 50 mg/kg/day, respectively), PYM II (2.7 mg/kg/day), PYM II+FNA (2.7 and 12 mg/kg/day, respectively), and a vehicle control group. The agents were administered for 11 days from day 7 throughout 17 of gestation. PYM and FA were administered by gavage and FNA was administered intraperitoneally. Visceral and skeletal malformations were observed in the fetuses of both PYM I+FA and PYM II groups; these included dilatation of the lateral ventricle and fused ribs. No malformed fetuses were observed in the fetuses of the other four groups. External malformations were observed only in the fetuses of PYM II groups; these included cleft palate, cleft lips, and brachygnathia, among others. These results show that the concomitant gavage dosing of FA augments PYM embryotoxicity. The preventive effects of FNA were also confirmed.

Granule cells and the development of synapses with mossy fibres in the cerebellum of the jaundiced Gunn rat

The development of granule cells and the formation of synapses with mossy fibres were investigated in cerebella from jaundiced (j/j) Gunn rats with hereditary hyperbilirubinemia. The external granular layer was thinner than that in cerebella from heterozygous (+/j) Gunn rats without hyperbilirubinemia on days 12 and 15 after birth, and it had disappeared in places by day 18. Migrating granule cells decreased in number from days 12 to 18. In the internal granular layer, the paucity of granule cells became apparent on day 12 and a reduction in the number of cells was prominent from day 18 onward. More degenerating cells were found in j/j cerebella than in +/j cerebella on days 12 and 15. Mossy fibre-granule cell synapses (glomeruli) were immature in appearance in j/j and +/j cerebella from days 7 to 12; small, roundish mossy fibre terminals were in contact with a few dendrites of granule cells. After day 18, the glomeruli were mature in terms of shape in +/j cerebella. By contrast, the mossy terminals remained small and roundish, and the granule cell dendrites that surrounded the mossy terminals did not increase in number nor develop digitiform branches in j/j cerebella. The mossy terminals were partially surrounded by glial processes and were occasionally surrounded by large dendrites of Golgi cells, which made multiple synaptic contacts. Some degenerating mossy terminals were present from days 18 to 30. These anomalous glomeruli may be caused by insufficient synaptic contacts with granule cells.

Effects of sodium bicarbonate and ammonium chloride on the incidence of furosemide-induced fetal skeletal anomaly, wavy rib, in rats

Furosemide produces fetal wavy ribs when administered to pregnant rats during late gestation. The compound is also known to produce metabolic alkalosis in laboratory animals and man. In order to evaluate the effect of furosemide on maternal blood pH, Crj:CD(SD) female rats received an oral administration of 150 or 200 mg/kg of furosemide by gavage on day 16 of gestation and were bled at 4 hr post-dose. Compared to an average pH of 7.39 in control females, there was a significant elevation in blood pH in these furosemide-treated females (average pH of 7.44 to 7.48). When 2% sodium bicarbonate was provided in the drinking water for females treated with 150 mg/kg of furosemide, there was a further rise in maternal blood pH (7.52) compared to females treated with furosemide alone. Associated with this elevation in maternal blood pH was a marked increase in the incidence of fetal wavy ribs (87.6% compared to 27.6%). When females treated with 200 mg/kg of furosemide were provided with 0.5% ammonium chloride, furosemide-induced maternal alkalosis was corrected (pH decreased to 7.35) and there was a reduction in the incidence of fetal wavy ribs (7.0% compared to 37.2%). In addition, maternal blood pH among individual females was positively correlated with the incidence of fetal wavy ribs (r = 0.714). These results suggest that maternal metabolic alkalosis is involved in the pathogenesis of furosemide-induced wavy ribs.

Ellagic acid embryoprotection in vitro: distribution and effects on DNA adduct formation

Ellagic acid (EA) is a naturally occurring plant phenol that was recently demonstrated to protect cultured rat embryos from the embryotoxic effects of N-methyl-N-nitrosourea (MNU). The teratogenic mechanism of action of MNU, as well as other methylating agents, is debated: both cell death and mutation have been proposed. In some model systems, EA has been reported to selectively decrease the mutagenic DNA adduct O6-methylguanine (O6MG) when compared to the cytotoxic DNA adduct N7-methylguanine (N7MG). The present study was initiated to determine 1) the distribution of 14C-EA and 3H-MNU in the rat whole embryo culture model system and 2) the effects of EA on MNU-induced DNA adduct formation in this model system. 14C-EA (50 microM for 2 hr, known embryoprotective concentration; no MNU added) was used to demonstrate access of EA to the embryo within the 2 hr exposure period. The majority of EA (99.5%) remained in the media while tissue concentrations of 57.0 and 47.9 pmol/mg were attained in the yolk sacs and embryos, respectively. Similarly, MNU (75 microM for 1 hr, known effective concentration; no EA added) was distributed between the media, yolk sacs, and embryos at 99.7%, 73.7 and 112.9 pmol/mg, respectively. When non-radiolabeled EA (50 microM for 2 hr) was used to protect embryos prior to exposure to 3H-MNU (75 microM for 1 hr), the distribution of MNU in the model system was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Teratogenic phase specificity of butyl benzyl phthalate in rats

Pregnant rats were given butyl benzyl phthalate (BBP) by gastric intubation at a dose of 0.6, 0.75 or 1.0 g/kg on days 7-9, 10-12 or 13-15 of pregnancy. While treatment with BBP on days 7-9 or 13-15 at doses of 0.75 and 1.0 g/kg was significantly teratogenic, no evidence of teratogenicity was detected when BBP was given on days 10-12. The incidence of malformed fetuses was proportional to the dose of BBP. Treatment on days 7-9 with BBP at doses of 0.75 g/kg and above caused a significant increase in the number of skeletal malformations, such as fusion of the cervical vertebral arches and deformity of the thoracic vertebrae, but neither external nor internal malformations. Treatment on days 13-15 with two higher doses of BBP resulted in a significantly increased incidence of fetuses with external and skeletal malformations such as cleft palate and fusion of the sternebrae. The highest incidence of malformed fetuses occurred after treatment with BBP on days 13-15. It could be concluded that the susceptibility to the teratogenicity of BBP varies with the developmental stage at the time of administration.

Dicephalus, Arnold-Chiari malformation and spina bifida in a Japanese black calf

A case of dicephalus, Arnold-Chiari malformation (ACM) and spina bifida was reported in a Japanese Black calf. Both brains and crania showed the same abnormalities as those of the monocephalic cases with ACM and were mirror-images of each other. The common findings were elongation of the brain, caudal displacement and hypoplasia of the cerebellum, dorso-ventral compression of the skull, platybasia, and enlargement of the foramen magnum. The craniolacunia was also found in our case.

Developmental toxicity of caffeine in the larvae of Xenopus laevis

To examine the developmental toxicity of caffeine, Xenopus larvae just after hatching, were continuously exposed to 100-2,000 mg/L caffeine for 48 hours. Caffeine interfered with development of Xenopus larvae at a concentration of 100 mg/L and above in a concentration-dependent manner. Characteristic external abnormalities, such as shortened body with wavy fins, were observed, the severity of which was clearly concentration dependent. These larvae were frequently accompanied by abnormal body flexure and edema in the fin. Light microscopy revealed that exposure to caffeine induced severe damage in the myotome and neural tube, and at higher concentrations, the epidermal tissue was also affected. Myoblasts showed wide intercellular spaces, and their cytoplasm lost uniform staining. Ultrastructural studies of myoblasts revealed distinct myofibril disorganization and degeneration, and mitochondrial alterations. In the neural tube, cells at the dorsal part of tube showed wide intercellular spaces and some of them were segregated to the peripheral region. Furthermore, vacuole-like structures of various sizes appeared in the white matter. The outer layer of epithelial cells in the epidermis were vacuolated and swollen. With regard to the pathogenesis of myofibril damage, caffeine appeared to cause a disturbance of intracellular calcium regulation, by releasing calcium ions from the sarcoplasmic reticulum, and the mitochondrial changes observed in myotomal cells were considered to be reflective of this increased intracellular calcium ion levels. It is speculated that caffeine interferes with cell adhesion in the myotome and neural tube by affecting calcium ion regulation.

The natural history of congenital diaphragmatic hernia and pulmonary hypoplasia in the embryo

Up to now, descriptions of the natural history of congenital diaphragmatic hernia (CDH) associated with pulmonary hypoplasia (PH) are based exclusively on observations made in the fetal period. However, nothing is known about the events that take place in an embryo with CDH. Recently, an animal model of CDH and PH has been established in rat embryos to study the embryology and natural history of this lesion. We exposed 36 pregnant Sprague-Dawley rats to a single dose of 100 mg nitrofen on day 11 of pregnancy. A total of 356 staged embryos and fetuses from day 13 to day 21 were studied by light and scanning electronmicroscopy. The litters of 9 untreated rats (124 normal age-matched embryos and fetuses) served as controls. The abnormal development of the diaphragmatic anlage was first seen in embryos aged 13 to 14 days. A defect appeared in the dorsal part of the diaphragm, normally on the right side. The liver grew through this defect early on. Gut was found in an intrathoracic position only in the very late stages (day 21/22) and newborns. Compared to controls, lungs of nitrofen-embryos with CDH were smaller, depending on the size of liver found in the thoracic cavity. Histologically, compression of lung was absent at these stages. Most authors speculate that CDH results because the pleuroperitoneal canals fail to close at the end of the embryonic period (ie, week 8 to 10 in human development) leading to a defect in the dorsolateral region of the diaphragm. However, contradictory to this assumption, our findings indicate that diaphragmatic defects develop in early embryonic life.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of diethylene glycol monomethyl ether on pregnancy and postnatal development in rats

The effects of oral treatment of Wistar rats with diethylene glycol monomethyl ether (diEGME) were examined. In a preliminary dose-finding study with non-pregnant rats, diEGME treatment at doses up to 4,000 mg/kg/day on 11 consecutive days decreased relative weights of thymus and pituitary gland, white and red blood cell counts, hemoglobin concentrations and hematocrit levels. In pregnant rats, treatment at doses of > 3,000 mg/kg/day (over gestation days 7-17) caused total resorption of all litters. In teratology and postnatal studies, pregnant rats were treated with diEGME at doses of 0, 200, 600, and 1,800 mg/kg/day from day 7 through 17 of gestation. At 200 mg/kg, there were no adverse effects on either dams, fetuses, or neonates. At 600 mg/kg, dams were not affected, but fetal body weights were decreased, and fetal thymus and ossification were adversely affected. At 1,800 mg/kg, maternal thymus weights and food consumption were decreased, and visceral malformations of the cardiovascular system were seen in 28.0% of the fetuses. Only 6.3% of the pups delivered by dams treated with 1,800 mg/kg of diEGME survived for 4 days after birth. Thus, diEGME was teratogenic in Wistar rats, but the spectrum differed from that in Sprague-Dawley rats. In addition to teratogenicity, diEGME had significant adverse effects on postnatal development. The most sensitive organ to diEGME was the thymus in both dams and fetuses.

Neural tube defects in the parietal region of human embryos: failure to close or closure-reopening?

This is a follow-up study to earlier investigations on neural tube defects (NTD) in the Kyoto collection of human embryos. It includes an extensive examination of abnormal embryos which have been photographed and serially sectioned following routine histological preparation. Two new types of NTD are described in the parietal region (the roof of the third ventricle) which had previously been overlooked. These anomalies were found most commonly in embryos at the developmental period. Carnegie stage [CS] 16-23 (embryonic days 38-52). Hypotheses are advanced regarding the genesis of NTD and whether encephaloceles and NTD are part of a spectrum of malformation. This study also reinforces evidence that the occurrence of NTD is significantly higher in the embryonic period than at birth. Animal studies, using the guinea-pig are discussed with regard to the investigation of hypotheses put forward to explain the genesis of NTD.

Nitrofen-induced congenital diaphragmatic defects in CD1 mice

In previous clinical reports, we have documented the association of several morphologic changes with congenital diaphragmatic hernia or, perhaps more appropriately termed, congenital diaphragmatic defect (CDD). These anomalies include decreased cardiac mass with left ventricular hypoplasia in infants with left-sided CDDs (Siebert et al., '84), enlarged, asymmetric chests (Siebert and Benjamin, '87), and extrathoracic anomalies (Benjamin et al., '88), including urinary tract anomalies and elevated kidney weights in otherwise normal kidneys (Glick et al., '90; Siebert et al., '90). Hypoplastic lungs and hearts and enlarged chests are thought to result from the herniation of abdominal viscera into the thoracic cavity, but for the renal abnormalities, pathogenesis is unclear. The findings are intriguing, for they could mirror unrecognized developmental relationships between the diaphragm, lung, heart, and kidney. In order to further examine these issues and to test the applicability of experimentally produced CDDs to human disease, we administered nitrofen (2,4-dichlorophenyl-p-nitrophenyl ether), an herbicide known to produce diaphragmatic defects in rodents, to time-mated CD1 mice by gavage feeding on gestational days 8 and 9. Dosages were 200 (low dose) or 500 (high dose) mg/kg body weight, and fetuses were studied on gestational day 18. Diaphragmatic defects occurred in a dose-response fashion: 0% (0/48) control or sham-fed, 5% (5/104) in the low-dose group, and 25% (19/75) in the high-dose group. Several fetuses with cleft palate, renal agenesis, exencephaly/encephalocele, and/or Di-George sequence were noted at the high dose, the latter a previously undescribed finding. Diaphragmatic defects were primarily right sided and only associated with herniation of abdominal viscera in animals exposed to 500 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Radiation-related small head sizes among prenatally exposed A-bomb survivors

Of 1566 individuals prenatally exposed to the atomic bombings of Hiroshima and Nagasaki, 1473 had the circumference of their head measured at least once between ages 9 and 19. Among these 1473 individuals, 62 had small heads--the circumference of the heads was two standard deviations or more below the observed specific-age-at measurement mean. Of 26 cases with severe mental retardation, 15 (58%) had small heads. Most (86%) of the individuals with small heads were exposed in the first trimester (about < 12 weeks postovulation) or second trimester (about 12-24 weeks postovulation)--55% in the former period and 31% in the latter. Various dose-response relationships, with and without a threshold, have been fitted to the data grouped by the trimester or postovulatory age (weeks after ovulation) at which exposure occurred. A significant effect of radiation on the frequency of individuals with atypically small heads is observed only in the first and second trimesters and for the intervals postovulation of 0-7 weeks and 8-15 weeks. Although the risk of a small head at 0-7 weeks postovulation increases significantly with increasing dose, no increase in risk for severe mental retardation is noted in this period. No excess risk of a small head was seen in the third trimester (about > or = 25 weeks postovulation) or among individuals exposed at 16 weeks or more postovulation. The mean IQ values of mentally retarded cases with and without small heads were 63.8 and 68.9, respectively. No significant difference exists between these two IQ means, but both were significantly smaller than 96.4, the IQ value for individuals with small heads without severe mental retardation and 107.8, the value for the overall sample.

Teratogenic evaluation of p-tert-butylphenol formaldehyde resin (novolak type) in rats following oral exposure

The teratogenicity of p-tert-butylphenol formaldehyde resin, novolak type, (PTBP-FR) was examined in Wistar rats. Pregnant rats were fed diets containing 0, 2.5, 5 or 10% of PTBP-FR ad libitum from day 6 to day 15 of pregnancy. Maternal toxicity, as evidenced by a decreased maternal body weight gain and food consumption, was observed in the 5 and 10% dose groups. However, treatment-related clinical signs were not observed. No significant reductions in the fetal body or placental weights were observed in any dose group. There were no significant differences in the number of live fetuses, intrauterine deaths (dead fetuses and resorptions), or fetal sex ratios found between the PTBP-FR-treated and control groups. Although external and internal malformations including short tail, dilatation of the cerebral ventricle and the renal pelvis and dextrocardia, and some skeletal variations were observed in fetuses at some groups treated with PTBP-FR, the incidences of these morphological alterations were not statistically different from controls. In conclusion, PTBP-FR administered orally to Wistar rats during days 6-15 of gestation produced no related signs of developmental toxicity.

Embryotoxicity induced by alkylating agents: 7. Low dose prenatal-toxic risk estimation based on NOAEL risk factor approach, dose-response relationships, and DNA adducts using methylnitrosourea as a model compound

Prenatal-toxic risk estimation for the alkylating model compound methylnitrosourea (MNU) was performed using different procedures. Risk of low doses was estimated using linear extrapolation to zero (estimated ED0.1%: 0.1 mg/kg body wt MNU) as well as extrapolation by probit analysis based on a dose-response study (estimated ED0.1%: 1.6 mg/kg body wt). Furthermore, a "virtually safe dose" was established by means of the NOAEL risk factor approach (e.g., factor 30:0.03 mg MNU per kg body wt). In previous studies in murine embryos using MNU, we combined dose-response data and DNA adduct rate measurements and deduced that O6-methylguanine is a suitable variable for molecular dosimetry. In a tentative approach, we estimated the teratogenic risk of low doses based on the adduct rates of O6-methylguanine in the DNA of the embryos. It is concluded that in the case of steep dose-response relationships, which are typical for the majority of teratogenic effects, the NOAEL risk factor approach is more conservative than extrapolation based on probit analysis. Risk estimation using dosimetry with this model compound yields estimated incidences similar to linear extrapolation.

Vimentin and desmin expression in degenerating and regenerating dystrophic murine muscles

The distribution of the intermediate filament proteins (IFP) desmin and vimentin was studied in gastrocnemius, plantaris and soleus muscles of the dystrophic mouse strain ReJ 129 during postnatal development. Special attention was paid to the overall morphological changes in the distribution of these cytoskeletal constituents in degenerating and regenerating muscle fibres. In contrast to their normal counterparts, the dystrophic mice (ReJ 129 dy/dy) appeared to develop four types of distinct muscle fibres with immunohistochemically detectable aberrant IFP patterns. The distribution of desmin IFP differed in the dystrophic muscle fibres as compared to the normal fibres in that juxtanuclear aggregates of IFP were frequently seen. In contrast to the recent literature we conclude that these cells are regenerated myofibres exhibiting defective nuclear migration.

Histochemical and immunohistochemical distribution of glycosaminoglycans, type II collagen, and fibronectin in developing fetal cartilage of congenital osteochondrodysplasia rat (ocd/ocd)

The osteochondrodysplasia rat (ocd/ocd) is a lethal dwarfism. The ocd/ocd shows histological abnormalities of the epiphysis, characterized by a decrease in amount of glycosaminoglycans (GAGs) in the extracellular matrix (ECM). The present study describes histochemical and immunohistochemical distributions of GAGs, type II collagen, and fibronectin (FN) in abnormal humeral cartilage of the ocd/ocd fetuses on days 16-21 of gestation. A wide-spread region with severe necrosis was observed in the cartilage on days 20 and 21. The affected cartilage has small amounts of ECM, irregular columnizations, thinner hypertrophic zones, and expanded and pyknotic chondrocytes on days 16-21 of gestation. The severely expanded chondrocytes did not have cytoplasmic glycogens on days 19-21. Reactions for chondroitin sulfate (CS) and hyaluronic acid (HA) in the ECM were consistently lower in ocd/ocd than in +/+ during the entire period of observation, although there were granules immunoreactive to CS within the chondrocytes of ocd/ocd. The distribution of type II collagen seemed normal in relatively normal regions in the affected cartilage. Strong reactions for CS, HA, type II collagen, and FN were present in the necrotic region on days 20 and 21 of gestation. These findings suggest that the affected chondrocyte may have some defects in releasing ECM substances, which may be released by the process of cell rupture. We hypothesize that some defects in releasing processes inherent to the ocd/ocd cartilage may relate to cellular differentiation and cell death.

A decade of rabbit fertility data: study of historical control animals

Reproductive data for 1795 artificially inseminated Hra: (NZW)SPF control rabbits in 93 developmental toxicity studies conducted from 1980 through 1989 were summarized. Data were obtained during terminal Caesarean-sectioning procedures performed on animals which survived to day 29 of gestation and during postmortem evaluation of does which aborted, delivered prematurely, or were found dead. Significant seasonal variation was not observed. Average pregnancy rate, percentage of rabbits that aborted, and percentage of rabbits that delivered prematurely throughout the decade were 86, 2.0, and 1.6%, respectively. Average numbers of corpora lutea, implantations, live fetuses, dead fetuses, early resorptions, and late resorptions for each doe that survived to scheduled termination were 10.8, 7.8, 7.1, 0.02, 0.49, and 0.15, respectively. The various vehicles used, routes of administration, and a variety of maternal and paternal factors were compared with the fertility data, and no correlations were observed. Rabbits that aborted earlier in gestation had fewer implantations than does which aborted late or delivered prematurely. Does which resorbed 100% of their conceptuses had fewer corpora lutea and implantations when compared with rabbits in the remainder of the population. Rabbits pregnant at scheduled termination which had a low number of corpora lutea or implantation sites had higher than expected pre- and postimplantation losses relative to the population as a whole. Does with a high number of corpora lutea had significantly higher preimplantation loss relative to the general population. This may indicate the presence of a "ceiling value" for the number of ova that can become fertilized and/or implant when the ovulation rate is high and which probably varies according to strain as well as a number of factors related to the individual rabbit. Based upon the results of this study and the work of a previous author, a minimum of four corpora lutea may be necessary for the successful maintenance of pregnancy in the New Zealand white rabbit. The minimum number of corpora lutea required may be strain dependent and may bear a relationship to the normal litter size of the strain.

Selective lectin-binding sites of primordial germ cells in chick and quail embryos

To ascertain the histochemical characteristics of surface carbohydrates on avian primordial germ cells (PGC), we examined the distribution of binding sites for several biotinylated lectins in chick and quail embryos. Some binding sites were detected almost selectively with PGC but not with other embryonic sites. Of these, lectin from Sojanum tuberosum (STA) reacted with PGC in both avian species, whereas lectin from Wistaria floribunda (WFA) and Griffonia simplicifolia II (GS-II) reacted in the quail and the chick, respectively. The binding site for STA was found at the cell surface and cytoplasm of the PGC from their initial appearance in the germinal crescent through migration to sexually indifferent gonads, whereas the WFA reaction was seen at stages before and during migration. These reactivities showed most intensely on the surface of PGC at the peak of their migration. In contrast, GS-II binding site was restricted to the cytoplasm, and its distribution was similar to that of the periodic acid-Schiff (PAS)-positive glycogen granules in chick PGC. These results suggest that some selective binding sites on the PGC surface play a significant role in their migration and show that lectins STA, WFA, and GS-II can be used as probes for identification of the avian PGC.

Ellagic acid protects rat embryos in culture from the embryotoxic effects of N-methyl-N-nitrosourea

Ellagic acid is a naturally occurring plant phenol that has demonstrated anticarcinogenic and antimutagenic activity in several test systems. Given the common proposed etiopathogenic processes of mutagenesis, carcinogenesis, and teratogenesis induced by genotoxic chemicals, the present study was initiated to determine whether ellagic acid would protect rat embryos in culture from the teratogenic effects of N-methyl-N-nitrosourea (MNU). Ellagic acid alone (as used in these experiments; 50 microM in DMSO) was not embryotoxic. Ellagic acid (50 microM) significantly (P less than 0.01) prevented MNU (75 microM)-induced effects including mortality (absence of heart beat), abnormal formation of the cephalic neural tube derivatives, and delayed differentiation as assessed by a morphological scoring system. These embryoprotective effects were dose responsive. Sequential treatment of embryos with ellagic acid followed by MNU in fresh media also was embryoprotective with no diminution of effect. The site at which ellagic acid interrupts the critical teratogenic events induced by MNU is apparently within the embryo and/or placenta. This model of chemical embryoprotection may be useful in determining the role of cell death and/or mutation in the teratogenic mechanism of action of methylating agents.

Perinatal mortality and prevalence of major congenital malformations of twins in Taipei city

In order to examine perinatal mortality and prevalence of major congenital malformations in twins, deliveries in four teaching hospitals in Taipei City were studied. Among a total of 73,264 deliveries from October 1985 to June 1989, there were 844 pairs of twins. The zygosity of the twin pairs was determined by sex, placentation and 12 red blood cell antigens. There were 482 MZ and 252 DZ twin pairs identified, but the zygosity of a further 110 twin pairs was indeterminable due to lack of information on plancentation and/or blood types. A total of 4,573 singletons delivered in one study hospital from July 1986 to June 1987 were also studied as controls. The perinatal mortality rate was 7.5% for MZ twins, 1.4% for DZ twins, and 0.7% for singletons. The concordance rate of perinatal death was significantly higher in MZ (60%) than in DZ (0%) twins. The prevalence of major congenital malformations was 2.7% for MZ twins, 1.0% for DZ twins, and 0.6% for singletons. The concordance rate of major congenital malformations was 18% for MZ twins, but no DZ pair was concordant in any major congenital malformation. The concordance rate of facial clefts was 29% for MZ twins. There were 2 sets of conjoined twins giving a prevalence rate of 2.7 per 100,000 deliveries. These findings showing the prevalence of perinatal mortality and major congenital malformation to be highest in MZ twins, intermediate in DZ twins and lowest in singletons, suggest the importance of intrauterine environments in the determination of perinatal mortality and congenital malformations.

Teratogenic evaluation of butyl benzyl phthalate in rats by gastric intubation

Pregnant rats were given butyl benzyl phthalate (BBP) by gastric intubation at a dose of 0, 0.5, 0.75 or 1.0 g/kg on days 7-15 of pregnancy. In the 0.5 g/kg group, food consumption during the administration period was significantly decreased, but no adverse effect on the embryo-fetus was detected. High maternal lethality and complete resorption of implanted embryos in all the surviving dams were observed in the 1.0 g/kg group. Increased embryo-fetal death and decreased fetal weight were found at a dose of 0.75 g/kg which also caused reductions in maternal body weight gain and food consumption. A significantly and markedly increased incidence of fetal malformations was also detected in the 0.75 g/kg group. Cleft palate, fusion of the sternebrae and dilatation of the renal pelvis were mostly observed.

Embryolethality and teratogenicity of butyl benzyl phthalate in rats

Pregnant Wistar rats were given butyl benzyl phthalate (BBP) at a dose of 2.0% in the diet on days 0-20, days 0-11 or days 11-20 of pregnancy. Food consumption and body weight gain were decreased in pregnant rats given BBP. Pre-implantation loss in the BBP-treated groups was comparable to that in the control and pair-fed groups. All dams given BBP on days 0-20 or days 0-11 exhibited complete resorption of all the implanted embryos. No increase in post-implantation loss was found in pregnant rats given BBP on days 11-20. Marked teratogenicity was detected in fetuses of the dams given BBP on days 11-20. Cleft palate and fusion of the sternebrae were predominantly observed. Seventy-two of the 134 fetuses had a cleft palate. The incidence of malformations in this group was significantly and markedly higher than that in the control and pair-fed groups. In conclusion, the administration of BBP during the first and second half of pregnancy produced embryolethality and teratogenicity, respectively.

Cardiovascular anomalies in chick embryos produced by bis-diamine in dimethylsulfoxide

N,N'-bis(dichloroacetyl)-1,8-octamethylenediamine(bis-diamin e) (100 micrograms) dissolved in dimethylsulfoxide (DMSO) was administered to early developing chick embryos (Hamburger-Hamilton stage 9-21) in order to clarify the teratogenic effects on the cardiovascular system and to determine whether bis-diamine interferes with the migration of neural crest cells. Of 346 cases, 154 (44.5%) survived. The incidence of cardiovascular anomalies was 149 out of 154 cases (96.8%). Infundibular ventricular septal defect, double outlet right ventricle, and persistent truncus arteriosus were the primary cardiac anomalies observed in this study. A high percentage of these anomalies were accompanied by hypoplasia of the right 6th aortic arch artery and persistent left 4th aortic arch artery. Particularly, administration of bis-diamine to chick embryos at stage 13 resulted in a high incidence of persistent truncus arteriosus (64.3%). Bis-diamine has been suspected to inhibiting the migration of neural crest cells. However, neural crest cells were observed in the tunica media of the great arteries and the truncal valves of persistent truncus arteriosus produced by bis-diamine in chimeric embryos at stage 13. Morphological changes such as cell death were not observed.

Effect of period of exposure on the developmental toxicity of butyl benzyl phthalate in rats

The objective of the present study was to determine if periods of exposure would modify the developmental toxicity of butyl benzyl phthalate (BBP). Pregnant Wistar rats were given BBP at a dose of 2.0% in the diet on days 0-20, days 0-7, days 7-16 or days 16-20 of pregnancy. Food consumption and body weight gain were decreased in the pregnant rats given BBP. All dams given BBP on days 0-20 exhibited complete resorption of all the implanted embryos. Post-implantation loss in the pregnant rats given BBP on days 0-7 or 7-16 was higher than that in the control and pair-fed pregnant rats. No increase in post-implantation loss was found in the pregnant rats given BBP on days 16-20. Pre-implantation loss in the BBP-treated groups was comparable to the control and pair-fed groups. Striking teratogenicity was detected in fetuses of the dams given BBP on days 7-16. Cleft palate and fusion of the sternebrae were predominantly observed. About 95% of the fetuses in this group had cleft palate. The incidence of malformations in this group was significantly and markedly higher than that in the control and pair-fed groups.

Susceptible period for the teratogenicity of di-n-butyltin dichloride in rats

Pregnant rats were given di-n-butyltin dichloride (DBT) by gastric intubation at a dose of 20 mg/kg on days 7-9, 10-12 or 13-15 of pregnancy or at a dose of 20 or 40 mg/kg on day 6, 7, 8 or 9 of pregnancy. While treatment with DBT on days 7-9 was significantly and highly teratogenic, no evidence of teratogenicity was detected when DBT was given on days 10-12 or 13-15. Treatment on day 7 or 8 with both doses of DBT, but neither on day 6 or 9, resulted in an increased incidence of fetuses with malformations. The highest incidence of malformed fetuses occurred after treatment on day 8. The incidence of malformed fetuses was proportional to the dose of DBT. Anomaly of tail, anal atresia, club foot, omphalocele, deformity of the vertebral column, defect of the ribs and anophthalmia or microphthalmia were predominantly observed. It could be concluded that, following maternal exposure to DBT in rats, developing offspring are not susceptible to teratogenic effects of DBT on day 6 and that day 7 is the earliest susceptible period, day 8 is the highest susceptible period and day 9 is no longer a susceptible period for teratogenesis of DBT.

Pathogenesis of various forms of double outlet right ventricle in mouse fetal trisomy 13

The pathogenesis of double outlet right ventricle with or without pulmonary infundibular atresia in mouse fetal trisomy 13 was studied at the organ level using microdissection and scanning electron microscopy. Altogether, 394 karyotyped trisomic embryos were collected between 11 days and 16 hours of gestation (presence of a vaginal plug = day 1) and 15 days of gestation at intervals of 8 hours, and at 16 days of gestation. The hearts were perfusion-fixed, microdissected, and prepared to be observed in scanning electron microscope in the following standardized orientations: frontal, right or left profile, septal and parietal halves of the right ventricle and outflow tract (conotruncus). Comparison of 276 trisomic hearts with their normal counterparts described previously has shown that: the first pathognomonic feature is the abnormal anterior position of the proximal part of the parietal outflow tract ridge or of both ridges (at 12 days and 16 hours of gestation); the abnormal anterior fusion of these ridges ("coalescence") results in a mesenchymal mass behind which is deviated the pulmonary part of the outflow tract lumen; from 14 days and 16 hours of gestation on, this lumen is either obstructed, resulting in a supravalvar stenosis of the pulmonary trunk and subsequently evolving into double outlet right ventricle with pulmonary infundibular atresia; or, in a minority of cases, this lumen is not obstructed and the heart develops into double outlet right ventricle without pulmonary infundibular atresia. The pathogenesis of these malformations differs from most of the known hypotheses based on deductions from human malformed hearts, as well as from observations of the pathogenesis of similar outflow tract malformations, such as those found in the Keeshond dog or rats treated with trimethadione.

The prevalence at birth of cogenital malformations at a maternity hospital in Osaka City, 1948-1990

The frequencies of congenital malformations at St. Barnabas' Hospital, Osaka were studied during the period 1948-1990. There were 1,418 malformed infants diagnosed during the first week of life among a total number of 131,996 births during the period. Of the 1.07% of malformed children, 0.90% had single and 0.17% had multiple malformations. The birth prevalence was 1.07% in singletons and 1.20% in twins. There was significant difference in prevalence between males (1.15%) and females (0.97%). The prevalence was 0.88% for the period 1948-1958 and increased with each year cohort up to the recent period when the value was 1.38%. Varus deformities of feet was the most common defect (23.4 per 10,000 births), followed by polydactyly (finger) (7.8), anencephaly (7.1), cleft lip and palate (6.5), syndactyly (toe) (6.5), cleft lip (6.3), and Down's syndrome (6.1). The prevalence of conjoined twins was 1 in 65,551 deliveries. Significant differences occurred between males and females for cleft palate, cleft lip and palate, syndactyly (finger), oligodactyly (finger), and hypoplastic auricle. The prevalences for valgus deformities of feet, syndactyly (toe) and atresia ani increased significantly with the year cohort, whereas the prevalence of cleft palate decreased significantly with the year cohort. Overall prevalence was significantly higher in 1970-1990 (1.28% than in 1948-1969 (0.88%). Similar results were examined for cleft lip and palate, syndactyly (finger), syndactyly (toe), hypospadias, hydrocele testis, and Down's syndrome.