bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and Functions of Cell Surface Glycoconjugates in Brain Morphogenesis*
Authors: OOHIRA Atsuhiko , MATSUDA Motoko , MATSUI Fumiko , SHOJI Ryujiro , WATANABE Kimi
Published: May 2008

Abstract Migration of newly‐generated neuroblasts to their definitive locations to form the laminated architecture of the brain is crucial in brain morphogenesis. In order to understand the molecular mechanism operative in the neuroblast migration, cell surface or pericellular glycoconjugates were isolated from the rat brains at various developmental stages. Hyaluronate (HA), chondroitin sulfate proteoglycans (CS‐PGs), heparan sulfate proteoglycans (HS‐PGs) and polysialosyl glycoproteins (N‐CAMs) have been characterized so far. Our biochemical and immunohistochemical experiments indicate that HA and a CS‐PG participate in construction of the hydrated extracellular milieu for the directional migration of neuroblasts.

Dissociated fetal brain cells reaggregated and formed a tissue configuration, in aggregating culture for 48 h, similar to that observed in the original brain primordium. Therefore, one can consider that the in vitro process is regulated at least in part by the mechanism operative in brain morphogenesis in vivo. It was suggested that HS‐PGs and N‐CAMs were involved in the in vitro process of the tissue self‐organization as cell membrane components.

From these findings and others, we conclude that some developmental changes in the structure and the contents of these cell surface glycoconjugates of the brain are implicated in neuroblast migration in brain morphogenesis.
Development of the Vertebrate Heart and the Extracellular Matrix*
Authors: HIRAKOW Reiji
Published: May 2008

Abstract Three major topics in vertebrate cardiogenesis were surveyed with special attention given to the cellular migration and the extracellular matrix (ECM).

1. Prior to primitive tubular heart formation, cardiogenic (lateral mesoderm) cells migrate on the endoderm to the definitive position ventral to the foregut. SEM observations of newt embryos revealed a subtle network of fine fibrils on the endodermal cell surface. These ECM fibrils were proved to be composed of fibronectin by immuno‐SEM method using latex beads.

2. The epicardium does not differentiate in situ from so‐called “epi‐myocardium”, but is formed in such a way that tips of mesothelial cell clusters extending from the septum transversum region attach to the dorsal side of the cardiac loop and spread gradually over the myocardium, eventually covering the entire heart. Using ruthenium red‐containing fixative, precipitated ECM was found specifically on the myocardium.

3. Cells of the cushion mesenchyme are known to be liberated from the endothelial cells and migrate into the cardiac jelly. There is growing evidence that ECM affects the cellular behavior in this process. Furthermore, neural crest cells were shown to contribute to mesenchyme formation in the outflow tract. Disturbed formation of the cushion tissue likely results in various malformations of the heart.
Modifying Effect of Folinic Acid on Methotrexate‐induced Embryotoxicity in Rats
Authors: HARADA Yasushi , MISAWA Noriko , INOMATA Norikazu , YASUDA Mineo
Published: May 2008

Abstract Embryotoxicity of methotrexate (MTX) and modification of its effect by folinic acid (FA) were evaluated in rats. MTX was administered intraperitoneally to pregnant rats on day 9 of gestation (vaginal plug = day 0), and was followed by an intraperitoneal injection of FA after various time intervals (0‐8 hours). Two dose combinations were used; 0.3 mg/kg of MTX and 1.0 mg/kg of FA, and 3.0 mg/kg of MTX and 10.0 mg/kg of FA. The dams were sacrificed on day 20 of gestation, and the fetuses were examined for visceral and skeletal development. The results are as follows: 1) A single dose of 0.3 mg/kg of MTX resulted in high embryolethality and growth retardation in all live fetuses and a single dose of 3.0 mg/kg of MTX showed 100% embryolethality. 2) A single dose of 1.0 or 10.0 mg/kg of FA showed no embryotoxicity. 3) The mitigating effect of FA on MTX‐induced embryotoxicity was observed when FA was administered simultaneously with MTX, but was rapidly decreased as the time interval between MTX and FA dosings became longer. 4) Some live fetuses which escaped from MTX embryolethality showed growth retardation and dilation of the cerebral ventricles. The dilation of the cerebral ventricles was found even in the simultaneously treated groups, though the incidences were much lower than the belatedly treated groups.
Cryptophthalmia Syndrome with Laryngeal Atresia and Bilateral Renal Agenesis: A Case Report and a Review of the Literature
Authors: MASHIMOTO Hideo , IKEDA Takayoshi , MATSUO Takeshi , MAEDA Hiroshi , SHIMOKAWA Isao , FUJISHITA Hikaru
Published: May 2008

Abstract An autopsy case of the unilateral cryptophthalmia syndrome was presented, showing the lack of the eyelids formation on the right and the facial skin being continuous over the right eye. Potter's face, partial cutaneous syndactyly, clitorial hypertrophy, bilateral renal agenesis and absence of uterus were associated, and further laryngeal atresia was noted, leaving a small posterior opening and allowing a survival of only 10 min at birth. Histologic analysis of the right eye revealed that the cyst in the anterior segment was formed by the destruction of the lens itself. The pathogenesis of cryptophthalmia and laryngeal atresia was discussed.
External and Skeletal Observations on a New Lethal Mutant of the Rat: Congenital Osteochondrodysplasia with Systemic Subcutaneous Edema
Authors: SUZUKI Katsushi , KIKUKAWA Keiichiro , IMAMICHI Tomonori
Published: May 2008

Abstract Malformed rat newborns showing severe subcutaneous edema were frequently found dead in our Wistar‐Imamichi rat colony. Their family record suggested that this malformation would be an inherited disorder. Experimental crosses of the phenotypically normal litter‐mates revealed that this malformation was a new lethal mutant of the rat, following a single autosomal recessive inheritance. External features and skeletal anomalies of the mutant were carefully checked and compared to those of the phenotypically normal litter‐mates. The comparison revealed that (1) this mutant has a characteristic external appearance that includes shortening of the head, trunk, tail and extremities, systemic subcutaneous edema, protruding of the tongue and cleft palate, (2) the axial bones and appendices are shortened and deformed severely and (3) ossification status of the newborn is delayed in digital bones and advanced in the vertebral centra and arches, stemebrae, choracoid process and talus. Observation of the parturition showed that this mutant is born alive but die shortly after birth because of breathing insufficiency. Based on these observations, this mutant was diagnosed as congenital osteochondrodysplasia with systemic subcutaneous edema (ocd for the gene symbol). The mode of inheritance and the similarities to some genetical disorders of other species, including human, are discussed.
Behavioral Teratology Symposium “Advances in Behavioral Teratology Testings”
Authors: TANIMURA Takashi , KIHARA Takahide
Published: May 2008

Abstract The Behavioral Teratology Meeting, a satellite meeting to the Annual Meeting of the Japanese Teratology Meeting hold a symposium on behavioral teratology on July 24, 1986 in Tokyo. The invited to this symposium were four American speakers who came to Japan to attend the 4th International Congress of Toxicology.

Presentations of these guest speakers appear as review articles in Congenital Anomalies following this communication. In general discussion, many critical and suggestive comments were expressed by the participants on the selected topics of behavioral teratology; 1) species and strains, 2) developmental stage, 3) positive controls, 4) procedures and 5) interpretation, and these were briefly introduced.
Effect of Chaetochromin A, Chaetochromin D and Ustilaginoidin A, Bis (naphtho‐γ‐pyrone) Derivatives, on the Mouse Embryo Limb Bud and Midbrain Cells in Culture
Authors: TSUCHIYA Toshie , SEKITA Setsuko , KOYAMA Kiyotaka , NATORI Sinsaku , TAKAHASHI Atsushi
Published: May 2008

Abstract Mouse embryo limb bud (LB) and midbrain (MB) cells were prepared from day 10 mouse embryos and cultured as micromass cell islands for 5 days. Differentiation was determined by the number of stainable foci of differentiated cells, and the concentration at which each compound inhibited the formation of differentiated foci by 50% of the control value (IC50) was estimated according to the method by Flint and Orton (1984). The values of IC50 of L‐dopa, which is known as a teratogen, were 24 μig/ml in LB cultures and 12 μ/ml in MB cultures, respectively. Teratogenic hazards of three mycotoxins were compared in this system. Chaetochromin A and chaetochromin D, which were new naphtho‐γ‐pyrone dimers produced by Chaetomium sp., indicated strong inhibition (IC50 0.13‐0.24 μ/ml) in LB and MB cell cultures, and ustilaginoidin A, which was a naphtho‐γ‐pyrone dimer produced by Ustilaginoidea virens, inhibited at higher concentration than chaetochromins by several‐folds in LB and MB cultures.
Familial Occurrence of Congenital Stapes Footplate Fixation
Authors: MASUDA Yu , AKAGI Seiko , NISHIZAKI Kazunori , SUYAMA Kiyoko , NISHIKAWA Kunio , OGURA Yoshio
Published: May 2008

Abstract Congenital stapes footplate fixation is not so common in the clinical otology. The clinical features are the fixation of the stapedial footplate, and the consequent conductive hearing loss with flat curve at the level of 50 to 60 dB in air conduction since birth. Its familial occurrence have never been reported before. The authors found five these cases in one family. All five cases were females, two of whom were sisters and other three were cousins. Their mothers had not particular disturbances in the early stage of pregnancy. The sex‐linked heredity was highly suspected in this familial occurrence. All the cases showed bilateral conductive hearing loss. Tympanotomies on all cases revealed no abnormality of the middle ear cavity, except that all the stapes were not mobile at the footplate in spite of the normal shape. Openings of a small fenestra onto the footplate were performed and teflon piston wire prostheses were used to reconstruct the new conducting route. The excellent improvement of postoperative hearing was gained in all the cases. Furthermore, out of family members another three cases with hearing loss were found. Pathogenesis was discussed in consideration of the developmental process of the stapes and histopathological findings in the previous reports.
Dose‐Response Relationships in Prenatal Toxicity*
Authors: NEUBERT Diether , OCHERT Gerd , PLATZEK Thomas , CHAHOUD Ibrahim , FISCHER Bernd , MEISTER Reinhard
Published: May 2008

Abstract Data and considerations on the significance of establishing dose‐response relationships in embryotoxicity (and especially teratogenicity) are presented here.

The problems discussed include the following topics:

‐ analysis and transformation of experimental data;

‐ dose‐response curves for various embryotoxic effects;

‐ reproducibility of studies on prenatal toxicity;

‐ prenatal versus maternal toxicity;

‐ quantitative risk assessment;

‐ “threshold” for teratogenic effects;

‐ analyses of combinations of teratogens;

‐ relationship between molecular events and chemical teratogenicity.
Congenital Diaphragmatic Hernia Induced by Nitrofen in Mice and Rats: Characteristics as Animal Model and Pathogenetic Relationship between Diaphragmatic Hernia and Lung Hypoplasia
Authors: NAKAO Yoshitaka , UEKI Reiko
Published: May 2008

Abstract Congenital diaphragmatic hernia (CDH) and lung hypoplasia were induced in high frequency and dose‐dependently in the offspring from dams, treated orally with 2,4‐dichlorophenyl‐p‐nitrophenyl ether (nitrofen) during pregnancy in CD‐I mice and CD rats. Both in mice and rats, CDH found in the fetal and neonatal periods was a posterolateral type of diaphragmatic hernia (DH) showing a distinct side‐preponderance: the left‐side preponderance in mice and right‐side preponderance in rats. CDH in the offspring, surviving after weaning, was mostly of retrosternal type in mice and of pericardial type in rats. CDH induced experimentally in the present study can be regarded as an excellent animal model for human CDH in terms of both anatomical features and the time of appearance of different types of CDH as well as clinical symptoms.

Lung hypoplasia was observed in the offspring with and without CDH; though its severity was greater in those with CDH. The offspring with severe lung hypoplasia died of respiratory insufficiency during the neonatal period, regardless of the presence or absence of CDH. These findings suggest that lung hypoplasia is not a consequence of CDH, but that a common pathogenetic process in the early embryonic stage might involve both lung hypoplasia and CDH.
Synaptic Development and Related Disturbances*
Authors: INOMATA Kenichirou , IGARASHI Hiroaki , NASU Fumio , ARII Tatsuo
Published: May 2008

Abstract Characteristics of synaptic development are as follows: 1) an increase‐decrease in the number of synapses consisting of an over‐production followed by elimination, the end product being the maturing form; 2) with maturation, there is a transformation from the axo‐dendritic shaft synapses to the axo‐dendritic spine ones. In early development, synaptogenesis probably proceeds simultaneously with myelination. A suggestion that the critical period giving definitive impairments in the organization of synapses exists may be raised. Quantitative analyses of the mitochondrial number in. the presynapse, determined using conventional osmium tetroxide staining and the number of synaptic junction determined using the EPTA preferential procedure reveal the synaptic changes, both in normal development or in response to nutritional and pharmacological factors.
Species Specificity in Induction of Wavy Ribs: Failure of Furosemide to Induce the Anomaly in Rabbit Fetuses
Authors: NAKATSUKA Toshio , Fujii Takaaki
Published: May 2008

Abstract Despite the strong activity to induce wavy ribs in rat fetuses, furosemide does not seem to have such activity in the rabbit. Since wavy ribs are known to be repairable in the rat during the early postnatal period, there is a possibility that the anomaly once produced in rabbit fetuses disappeared before the examination at term because of their longer duration of gestation. In order to test this possibility, the authors administered furosemide to pregnant rabbits and examined fetuses shortly after the treatment period for the presence of wavy ribs. Furosemide even at doses which were apparently toxic to maternal animals failed to produce the anomaly. Based on these results and in view of the absence of its occurrence in the literature, it may be concluded that there is species specificity in the induction of wavy ribs and this anomaly does not occur in rabbit fetuses. The temporal difference between the onset of ossification and that of increased myometrial contractions may probably be involved in this species specificity.
A Quarter Century of Thalidomide Embryopathy*
Authors: KIDA Mitsushiro
Published: May 2008

Abstract Some 137 patients with thalidomide embryopathy have been registered. Of them, 65 were male and 72 female. The age of patients who had a medical examination from 1976 to 1983, ranged from 7 to 22 years. The mean age was 17.0 ± 2.3 (mean ± SD) years. The number of hearing impairments were 35 (25.6%), limb defects were 55 (40.1%) and combined defects were 47 (34.3%). In order to determine the mutual relationships of 34 abnormal symptoms, the correlation coefficient was calculated, and cluster analysis was carried out by utilizing the result. There was a strong inverse correlation between deformities and hearing impairments. The 34 symptoms were divided into three groups. In the first group 11 symptoms were included, but there was little mutual relationship. Fifteen symptoms belonged to the second group, which evidenced strong mutual relationships. The 8 symptoms belonging to the third group were central to all of the symptoms.
A Clinical and Experimental Study on Longitudinal Deficiencies in Lower Limbs in Relation to Pathogenesis of Cleft Foot
Authors: OGINO Toshihiko , KATO Sadatoshi , MONJI Junichi
Published: May 2008

Abstract In order to determine whether cleft foot is caused by the same mechanism as tibial and fibular ray deficiencies, clinical cases of these anomalies and those in rat fetuses induced by myleran were analyzed. In tibial and fibular ray deficiencies, arrest of tibia or fibula was closely related to the missing of toes and tibial and fibular ray deficiencies can be accepted as an occurrence of so called longitudinal deficiency. On the other hand, cleft feet were frequently associated with central Polydactyly and syndactyly. In our experimental study, the critical period of formation of cleft foot was different from that of tibial ray deficiency, but it was similar to those of central Polydactyly and syndactyly. It seems that cleft foot is caused by the abnormal induction of toe rays as in cleft hand and does not belong to the same group as tibial and fibular ray deficiencies.
Biochemical Studies on the Effect of Maternal Hyperphenyl‐alaninemia on Fetal Brain Maturation of Mice
Authors: YAMAWAKI Yasushi , OHYA Noriaki , SHIMADA Morimi
Published: May 2008

Abstract The effects of maternal hyperphenylalaninemia during pregnancy on the biochemical maturation of neonatal mice brains were examined, thus establishing the critical concentration of phenylalanine in maternal blood and the critical period of maternal hyperphenylalaninemia during pregnancy. Hyperphenylalaninemia was induced by giving chow supplemented with 3%, 4%, 5%, or 6% phenylalanine (Phe.) and 0.12% p‐chlorophenylalanine (PCPA) for at least one month and then throughout pregnancy. Some of the pregnant mice fed the 6% Phe. diet before pregnancy received a normal diet after conception (6%: A).

Offspring from each group were decapitated two days after birth. Their brains were removed and then divided into the cerebrum and the brain stem including the cerebellum. Total protein, RNA and DNA were measured biochemically. All kinds of markers of the newborn mice born to the 5% and 6% mothers, the weight and the contents of the protein, RNA and DNA, were reduced significantly in both the cerebrum and brain stem. In the 4% group, however, only the brain stem was affected. The 3% group showed reductions neither in the weight nor the protein and nucleic acids contents in both the cerebrum and brain stem. In the 6%:A group, in which the diet was returned to normal just after conception, total protein, RNA and DNA were reduced in the brain stem, but not in the cerebrum.

These results suggest that the critical concentration of maternal blood phenylalanine during pregnancy in the mouse is 11mg/dl, which is that corresponding to the 3% group, and also suggest that it is too late to begin the low phenylalanine diet after conception.
Abnormal Cerebral Vascularity in Mice with Histogenetic Disorders of the Cerebral Cortex and Postnatal Manifestation of Hydrocephalus
Authors: KIMURA Shoko , FUKUI Yoshihiro , KAMEYAMA Yoshiro
Published: May 2008

Abstract Pregnant mice were exposed to 60Co gamma‐irradiation on day 13 of gestation, and the offspring after birth were examined in histological sections and microvascular specimens with India ink, in order to know the pathological changes leading to postnatal manifestation of hydrocephalus. The cerebrospinal fluid pressure was also measured.

The offspring from birth to 12 days of age showed microcephaly or dysgenetic hydrocephaly with severely deranged cerebral cortical architecture. The microvascular specimens of these brains showed a deranged vascular pattern and poor vascular network in the brain mantle. Its severity was in proportion to that of the disorder of the cortical architecture. These brains were involved with blood congestion and perivascular hemorrhage in the periventricular white matter, and consequently with cystic degeneration and pseudoventricle formation, which changes became evident at 7 to 10 days of age. The cerebrospinal fluid pressure was not different from that of non‐treated control mice until 12 days of age. Around 14 days of age, the pressure began to increase concurrently with an external appearance of vaulted skull, indicating a transformation from degenerative ex vacuo type of hydrocephaly to progressive high‐pressure hydrocephalus.

These results suggested that histogenetic disorders of the cerebral cortex caused abnormal vascular formation in the brain mantle and that the consequent intracerebral circulatory disturbance played a significant role for degenerative changes of the brain tissue and a failure of the cerebrospinal fluid dynamics at the time of brain growth spurt.
Effects of Folic Acid and Folinic Acid on Pyrimethamine Teratogenesis in Rats
Authors: KUDO Gen , KOKUE Eiichi , HAYAMA Toyoaki
Published: May 2008

Abstract The effects of folic acid (FA) and folinic acid (FNA) on the teratogenicity of the antifolate drug pyrimethamine (PYR) were examined in rats. PYR and FA were orally administered with mashed feed. FNA was intraperitoneally injected. The drugs were administered for 5 days of day 11–15 of gestation. Six groups were made; G‐I PYR 1.6 (mg/kg/day), G‐II PYR 3.6, G‐HI PYR 1.6 + FA 50, G‐IV PYR 3.6 + FNA 12, G‐V FA 50, G‐VI control. No malformations were found in G‐I, IV, V and VI. All fetuses in G‐II and III had malformations. Main malformations in G‐II and III were cleft palate and brachygnathia. Accordingly it might be demonstrated that the teratogenicity of PYR was potentiated by concurrent FA in rats.
Developmental Toxicity of Aspirin Prenatally Given to Rats: Assessment in Slc: Wistar‐KY Rats
Authors: OKAMOTO Masaharu , KIHARA Takahide , TANIMURA Takashi
Published: May 2008

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.
Congenital Hydrocephalus in Japan 1969–1982: Secular Trends, Geographical and Social Class Variations
Authors: IMAIZUMI Yoko
Published: May 2008

ABSTRACT  Nation‐wide data in Japan between 1969–1982 on 3,650 cases of fetal death and 2,397 cases of postnatal death caused by congenital hydrocephalus were analyzed. The prevalence rate of congenital hydrocephalus decreased yearly. This reduction is attributed to prenatal detection and selective abortion among fetal deaths, and surgical correction of hydrocephalus postnatally. The prevalence rate per 1,000 births was 0.22 in urban areas and 0.25 in rural areas between 1969–1982, and the difference was significant. The prevalence rate was slightly higher in the southwest part of Japan than in the northeast. Social class variation in the prevalence rate was present.
Chondrodysplasia Punctata with Myopathic Involvement
Authors: NOGAMI Hiroshi , OKI Takashi , ISHIDA Yoshihito , MURACHI Shunji , IYODA Kazuhito
Published: May 2008

Abstract Histopathological examination of the muscle and the iliac crest cartilage were performed in a one year 6‐month‐old girl with chondrodysplasia punctata. The patient's mother was also affected.

Light micrographs of the cartilage revealed long, tongue‐like processes extending into the osseous tissue in the osteochondral junction. Electron micrographs of the cartilage showed an increased number of lipid droplets in chondrocytes and more numerous hydroxyapatite clusters and matrix vesicles in the inter‐territorial matrix. Pathological findings of the biopsied muscle included derangement and/or missing cross‐striations, together with many vacuoles in the muscle fibers. These degenerative changes in both the muscle and the cartilage as well as many associated complications may suggest that chondrodysplasia punctata is a generalized metabolic disorder.
Dose‐related Induction of Digital Malformations in Rats by 5‐Azacytidine: Description of the Defects
Authors: KURISHITA Akihiro , IHARA Toshio
Published: May 2008

Abstract Dose‐related changes of 5‐azacytidine (5‐AC) induced digital malformations are reported. Dosages of 0.4, 0.5, 0.6, 0.7, and 1.0 mg/kg of 5‐AC were injected intraperitoneally into pregnant rats on day 13 of gestation. The susceptibility order of each digit was the second > third > first > fourth > fifth in the forepaw and the second > first > third ė fourth > fifth in the hindpaw. In the forepaw, the percentages of cutaneous syndactyly with closely apposed metacarpals or osseous syndactyly between the first and second digits (type FA defect) and brachydactyly of the third digit (type FB defect) were increased in a clear dose‐related trend. In the hindlimb, the percentages of osseous or cutaneous syndactyly between the first and second digits (type HA defect), brachydactyly or ametatarsia of the second digit (type HB defect), and osseous or cutaneous syndactyly, closely apposed metacarpals, lateral metacarpal fusion, or osseous or cutaneous syndactyly with lateral metacarpal fusion or closely apposed metacarpals between the third and fourth digits (type HC defect) reached a maximum at 0.7 mg/kg of 5‐AC and then decreased. However, the percentages of ectrodactyly, 1 missing digit (type M1 defect) or 2 missing digits (type M2 defect), were increased from 0.6 mg/kg or 0.7 mg/kg, respectively. Ectrodactyly, missing 3 digits (type M3 defect), was rarely observed in the dose range used.
Distribution of Corticogeniculo‐Neurons and Projection of Geniculocortical Fibers in Methylazoxymethanol‐lnduced Microcephalic Rats
Authors: FUNAHASHI Atsushi
Published: May 2008

Abstract In the rat with methylazoxymethanol (MAM)‐induced microcephaly, the distribution of corticogeniculate neurons and the projection of genicurocorti‐cal fibers were examined using the horseradish peroxidase (HRP) tracing technique. In agreement with the previous studies, HRP‐labeled corticogeniculate neurons in the MAM‐rats were irregularly distributed and reduced in number in the occipital cortex and neurons in the LGNd also showed developmental deficits such as reduced cell number and abnormal distribution. It was first demonstrated that in the MAM‐rats, the density of HRP‐labeled geniculocortical fibers observed in the corpus calosum was remarkably low than the control. Moreover, HRP‐labeled fiber plexus in the MAM‐rats revealed a layer‐like appearance similar to the control. However, its major location did not coincide with layer IV because of the obscure lamination pattern in the superficial and intermediate layers. Besides, in the MAM‐rats, the density of the HRP‐labeled geniculocortical afferents in the plexus was abnormally high and these afferent terminals showed uneven distribution compared with more uniform distribution in the control. From these observations, it is suggested that there is a possibility of abnormal neuronal contacts between the geniculocortical afferent and the target cortical neurons in the visual cortex.
Effects of Copper and Hydrocortisone on Cell Cycle of Cultured Fibroblasts from the Macular Mouse as a Model of Menkes Disease: DNA Analysis by Flow Cytometry
Authors: TACHIIRI Toshiharu , OHTA Shigeru , YAMANO Tsunekazu , OHYA Noriaki , SHIMADA Morimi
Published: May 2008

Abstract Effects of copper and hydrocortisone on the proliferation of cultured fibroblasts from macular mouse, a model of Menkes kinky hair disease, were analyzed by flow cytometry. In fibroblasts from the macular mouse, copper induced cytotoxicity and S‐phase accumulation of cell cycle were observed at lower concentrations of copper than in fibroblasts from the controls. However, the fibroblasts cultured with a combination of copper and hydrocortisone revealed recruitment of cell cycle. These results suggest that the proliferative activity of the cells from a macular mouse are more vulnerable to an excess amount of copper than normal, and that supplementation of hydrocortisone is effective for the Menkes kinky hair disease.
Cytochemical Maturation of the Notochord in Dysraphic Mice
Authors: WILSON DORIS B. , WYATT DARLENE P.
Published: May 2008

Functional aspects of notochordal maturation in dysraphic loop‐tail (Lp) mice were analyzed by means of ultrastructural cytochemistry on embryos at 9–12 days of gestation. Notochordal cells in normal (+/+; Lp/+) and dysraphic abnormal (Lp/Lp) embryos showed ultrastructural features consistent with secretory activity, particularly at 10 and 11 days. With specific cytochemical staining, glycogen was observed as thiocarbohydrazide‐silver proteinate particles sparsely scattered throughout notochordal cells of normal and abnormal embryos at 9 and 10 days, with aggregates common at 11 and 12 days. With tannic acid and ruthenium red treatment, the perinotochordal space in abnormals showed differences in the density of stained filaments from that in normal embryos, suggesting a defect in glycosaminoglycan deposition. In abnormal embryos, the notochord became located relatively more distant from the open neural folds than from the closed neural tube in normal littermates, and the arrangement of the adjacent mesenchymal cells was irregular and less dense than that in the normal embryos. Thus, although the ultrastructure of the notochordal cells was relatively normal, the features indicative of aberrant interactions among the notochord, neural folds, and adjacent mesenchymal cells may be of significance in the etiology of dysraphism in this mutant.
Strain Difference in Effects of Ethanol Treatment on Fetal Development in C57BL and DBA Mice
Authors: FUKUI Yoshihiro , NARUSE Ichiro , HOSHINO Kiyoshi , KAMEYAMA Yoshiro , TAKEUCHI Yoshiki
Published: May 2008

Pregnant C57BL and DBA mice were treated with i. p. injection twice of 25% ethanol (3.97 g/kg × 2), four hours apart, on day 7, 8, 9, 10, 11, 12 or 13 of gestation. They were killed on day 18 of gestation, and the fetuses were examined for external and skeletal malformations. In order to determine the blood ethanol levels, nonpregnant animals were treated with the same dose of ethanol and then killed at 0.5‐16 hours after injection.

Fetal mortalities of DBA mice were higher than those of C57BL mice. The body and brain growth retardations were severer and the incidence of malformations was higher in C57BL mice than in DBA mice. The most frequently observed malformations were microphthalmia and digital malformations in C57BL mice, and open eyelids in DBA mice. Blood ethanol reached the maximum level within half an hour after the second injection in both strains, and was significantly higher in DBA mice than in C57BL mice 2–15 hours after the second injection. It is difficult to explain the strain difference of embryotoxicity between C57BL and DBA mice on the basis of only the difference in blood ethanol level in the present study.
Effects of Phenytoin on Morphology of Otolith in the Rat Fetuses
Authors: MURAKAMI Yoshinori , OGASAWARA Hiroyuki , MISAWA Noriko , FURUKAWA Yasuo
Published: May 2008

The effect of phenytoin on morphology of otoliths was investigated in rat fetuses. Pregnant rats were administered with phenytoin (PHT) 50, 100 and 200 mg/kg/day on days 11–14 of pregnancy and the fetuses were removed on day 20 of pregnancy. Methyl salicylate cleared specimens were prepared and the otoliths were scored for morphological completeness.

Otolith score decrease was observed only in utricles of the fetuses treated with PHT 200 mg/kg/day with a statistical difference. The most remarkable morphological change in otoliths was that the utricular otolith and the saccular otolith were connected and the otoconial crystals were visible between utricular and saccular otoliths. The frequency of this conjoined utricule and saccule was about 30% of the fetuses treated with PHT 200 mg/kg/day. From these results, the threshold level of PHT for induction of otolith abnormalities was estimated to be between 100 and 200 mg/kg/day.
Contiguous Gene Syndromes as Multiple Anomalies Syndromes: Molecular Basis and Approach to Gene Cloning
Authors: NIIKAWA Norio
Published: May 2008

Recent knowledge on molecular basis of several contiguous gene syndromes as multiple anomalies syndromes, such as Prader‐Willi syndrome (PWS), Angelman syndrome (AS), Beckwith‐Wiedemann syndrome (BWS), tricho‐rhino‐phalageal syndrome types I (TRPS I) and II (TRPS II or LGS), and complex glycerol kinase deficiency (CGKD), are reviewed. Based on the results of DNA deletion studies and on the evidence for the genomic imprinting mechanism of both PWS and AS, a model for the occurrence of the two syndromes is proposed. Also, a strategy of the microdissection/microcloning technique as a reverse genetics technique, i. e., direct cloning of chromosomal DNAs from a defined region of human chromosome, particularly for the cloning of the exostosis gene in TRPS, is presented.
Investigation of DNA Synthesis and Cell Condensation in the Developing Rat Hand Plate by the BrdU/anti‐BrdU Technique
Authors: OHSHIO Itaru , OGINO Toshihiko , NAGASHIMA Kazuo
Published: May 2008

Abstract: DNA synthesis and cell condensation in the developing hand plate of the rat were examined by a BrdU/anti‐BrdU immunohistochemical study. DNA‐synthesizing cells were distributed uniformly in the mesenchyme of the hands until day 12.5 in rat embryos. From day 13.0, these cells were distributed in the interdigital mesenchymal areas, leaving rare labeled cells in sites of cell condensation (i.e., in the digital rays). After day 14.5, DNA‐synthesizing cells were confined to the interdigital areas near the digital rays. On day 15.0, DNA‐synthesizing cells appeared in the areas of joint formation. In the epidermis. DNA‐synthesizing cells were uniformly found in the period of digital‐ray formation. When the mesenchymal cells labeled on day 12.0 were followed from day 12.5 until day 14.0 of embryogenesis, they were found to become concentrated in the digital rays. From these findings, we conclude that the cells which are synthesizing DNA and actively dividing in the mesenchyme at day 12.0 migrate to the digital rays, where they undergo cell condensation. The experimental models and techniques employed in this study will be useful for investigations of normal development as well as teratogenesis of the extremities.
Five Families with Mohr‐Wriedt Type Brachydactyly of the Index Finger
Authors: MIURA Takayuki
Published: May 2008

Abstract: Twelve patients with inherited shortening of the middle phalanx of both index fingers were found in 122 patients with congenital clinodactyly without any major hand anomalies. The morbidity rate in females was 53.6% and in male it was 50.0%. Webbing between the second and third toes was found in three, and clinodactyly of the second toe in four. Characteristic features of this anomaly are a short and delta‐shaped or rhombus‐shaped middle phalanx of the index finger. Hand pattern profiles revealed that the middle phalanges of the long and ring fingers are shortened to a variable degree.
Morphogenetic process of dysraphic malformations induced by thalidomide in JW‐NIBS rabbits
Authors: MIKAMI Takashi , MATSUBARA Yoshio
Published: May 2008

Abstract: Our previous study demonstrated thalidomide‐induced anencephaly and holoprocencephaly at a high frequency in JW‐NIBS rabbits. In order to know the early morphogenetic process of these two malformations, thalidomide was orally given to pregnant JW‐NIBS rabbits on day 7 or on days 6–9 of gestation, and the embryos were examined on days 9–13 in histological sections and scanning electronmicroscopic specimens.

The preponderant site of thalidomide‐induced dysraphic change was the midfrontal portion of the prosencephalic vesicle. A widely opened cephalic neural tube at this portion and consequent eversion of the telencephalic wall observed in day‐9‐embryos (231 hours postcoitus) was the first change of most anencephaly in this experiment. Incomplete closure of the cephalic neural tube under the closed surface ectoderm observed at the midfrontal portion of day‐9‐embryos was divided into two types: One type showed a contact of the neural folds but no histological continuation, and the other type evidenced a degeneration of the neuroepithelial tissue at the closing site and hypoplasia of the surrounding mesenchymal tissue. The mesenchymal tissue over the neuroepithelial layer showed curled cellular processes and a loose interconnection in scanning electronmicroscopic specimens. The midfrontal encephalocele observed in day‐13‐embryos could be regarded as the consequence of the former type of incomplete closure. Defective formation of the longitudinal fissure of the telencephalon due to the midfrontal encephalocele was the cause of holoprosencephaly later. Not only unclosure of the neural tube but also the latter type of incomplete closure was considered to manifest anencephaly.
Bone‐Staining Technique for Fetal Rat Specimens without Skinning and Removing Adipose Tissue
Authors: KAWAMURA Satoshi , HIROHASHI Atsuko , KATO Terushige , YASUDA Mineo
Published: May 2008

Abstract: A rapid procedure was developed for staining fetal rat specimens. Full‐term rat fetuses were fixed in 99% ethanol and only thoracoabdominal organs were removed. Without skinning and removing adipose tissue and eye balls, the specimens were placed in 85% ethanol containing 1.5% KOH and 0.0015% alizarin red S for 5 days. The specimens were macerated in 1% aqueous KOH and cleared in 50% glycerin solution. The skeleton was visible through surrounding tissue containing adipose tissue which became transparent.
The Interaction of Oligosyndactyly (Os) Gene and 5‐Fluorouracil (5‐FU) in the Manifestation of Digital Malformations in Mice
Authors: IMAMURA Takakazu
Published: May 2008

Abstract: The heterozygotes of Oligosyndactyly (Os) gene manifest syndactyly on fore‐and hindfeet and sometimes axial oligodactyly in mice. 5‐Fluorouracil (5‐FU) is known to produce various types of digital malformations in mice. The present experiment was designed to examine possible interactions of Os gene and 5‐FU in the induction of digital malformations in mice. Female Slc:ICR mice were mated with F1 males (Os/+ or +/+) which were obtained from the cross between female ICR and male C57BL‐Os/+ mice. Pregnant females were treated with a single intraperitoneal injection of teratogenic dose (20 mg/kg) or marginal teratogenic dose (10, 7.5 and 15 mg/kg) on day 9, 10 and 11 of gestation, respectively. On day 17 or 18 of gestation, fetuses of treated and non‐treated control groups were examined externally and in bone and cartilage double‐stained specimens. The teratogenic dose of 5‐FU increased the expressivity of Os gene and, in turn, Os gene caused an increased severity of 5‐FU‐induced postaxial oligodactyly. The interaction between Os gene and marginal teratogenic dose of 5‐FU varied according to the time of treatment. Increased expressivity of Os gene could be observed in the groups treated with the marginal teratogenic dose of 5‐FU on day 10 and day 11.
Effects of Pyrimethamine and Folic Acid on Plasma Level of 5‐Methyltetrahydrofolic Acid in Rats
Authors: TSUNEMATSU Kunitoshi , KUDO Gen , SHIMODA Minoru , KOKUE Eiichi , HAYAMA Toyoaki
Published: May 2008

Abstract: The relationship between pyrimethamine (PYR) teratogenesis and the plasma level of 5‐methyltetrahydrofolic acid (5MF), known as an active form of folate in plasma, was studied in rats using an HPLC‐ECD method for 5MF determination. The rat received, for 5 days, in‐feed PYR with or without folic acid (FA), which was previously reported as a potentiator of PYR teratogenesis. PYR alone caused a dose‐dependent decrease in the plasma 5MF level after the 5 day dosings. A potentiated decrease in the 5MF level was observed after the concomitant dosing of PYR with FA. The concomitant dosing of PYR 1.6 mg/kgBW/day (subteratogenic dose of PYR alone) with FA 50 mg/kg/day, which was 100% teratogenic dose in our previous report, decreased the 5MF level more than that after the dosing of PYR 3.6 mg/kg/day alone (100% teratogenic dose of PYR alone).

The sequential changes of the plasma 5MF level after the single oral dosing of PYR 3.6 mg/kg with or without oral FA 50 mg/kg also revealed a strong potentiative effect of oral FA on the 5MF‐level‐lowering effect of PYR. These results indicate that a decrease in the plasma 5MF level may be related to PYR teratogenesis.
Congenital Hydrocephalus Induced in Rats by Prenatal Administration of Ethylenethiourea
Authors: TAKEUCHI Ikuo K. , TAKEUCHI Yoshiko K.
Published: May 2008

Abstract: Pregnant Wistar rats were given a single i.p. injection of 30 mg/kg ethylenethiourea (ETU) on one of gestational days 8.5 to 20.5. After rearing to postnatal day 20, the offspring were sacrificed and their brains were excised. Numerous brains removed from the pups prenatally treated with ETU on any day from gestational days 12.5 to 20.5 showed dilatation of lateral ventricle in various degrees. Histological examination revealed forking and stenosis of third ventricle in these brains. Since the degree of the third‐ventricular stenosis roughly corresponded to the degree of dilatation of lateral ventricle, this anomaly is considered to be the main cause of congenital hydrocephalus induced in rats by prenatal ETU‐treatment. The embryological study showed that the ependymal lining of the third ventricle was partially denuded in the fetuses 24–48 hours after ETU‐treatment, and also that the denuded ependymal lining was never repaired during the following gestational days; instead, the ventricular walls fused laterally in the area where the ependymal lining had been denuded.
Participation of Neural Crest Cells in Cardiovascular Morphogenesis of Chick Embryos
Authors: HAYAKAWA Kunio , OKISHIMA Takahiro , TAKAMURA Kazushi , OHDO Shozo
Published: May 2008

Neural crest cells appear on top of the neural folds at closure of the neural tube. These cells are capable of migrating and differentiating into multiple tissues. In 1983, Kirby et al., using chimera methodology, reported that cranial neural crest cells participated in aorticopulmonary and truncal septation. Since that time, many experimental studies have been done in this field. In this paper, we report new experimental findings and review four areas of study on neural crest cells, i.e. their general characteristics, participation of neural crest cells in formation of the normal heart, cardiovascular anomalies due to ablation of the neural crest cells, and the relationship between neural crest cells and congenital malformation syndromes, especially the DiGeorge sequence.
Morphological Analysis of Neural Tube Defects in Non‐obese Diabetic (NOD) Mouse Embryos
Authors: ANDO Seiichi , OTANI Hiroki , TANAKA Osamu , MORITAKE Kouzo
Published: May 2008

Neural tube defects (NTDs) were demonstrated to occur at a high rate (29.4%) in non‐obese diabetic (NOD) mouse embryos on day 13 of gestation. Macro‐scopically, three different forms of NTDs were observed: the combined form of exen‐cephaly and myeloschisis, the pure form of exencephaly, and that of myeloschisis. The neural walls of the open tube were everted bilaterally. It was microscopically demonstrated that NTDs were composed of not only the everted neural walls but also voluminous mesenchymal tissue adjacent to the everted neural walls. The everted neural wall had three‐layered structure made up of outer, intermediate, and inner zones. The morphological findings of the intermediate and inner zones were similar to those of mantle and marginal layers in the normally closed neural tube. However, the outer zone, which corresponded to the ependymal layer in the normal neural tube, had characteristic findings. Namely, the cells were small, round and uniform in shape. Almost no mitotic figures were observed in this zone, and electron microscopic investigation revealed few cytoplasmic organelles. Of 9 NOD mouse embryos with NTDs, 2 exhibited duplicated notochords. In one of these two embryos, an aberrant tubal structure was formed of neural tissue. The plausible causes of NTDs in NOD mouse embryos were discussed based on these findings.
Delayed Maturation of Fetal Lung in Yellow KK Mice
Authors: OOSHIMA Yojiro , SHIOTA Kohei , IHARA Toshio
Published: May 2008

Yellow KK mice have the Ay allele and spontaneously develop non‐insulin dependent diabetes mellitus (NIDDM). In the present study, female yellow KK mice were mated at 7 or 13 weeks of age (the average blood glucose levels were ca. 260 and 500 mg/dl, respectively), and their fetuses were examined on days 18 or 19 of gestation.

The fetuses from 13‐wk‐old dams were smaller than those from 7‐wk‐old dams. The average lung weight on day 19 of gestation was slightly greater in the fetuses from 13‐wk‐old dams than in those from 7‐wk‐old dams (23.3 vs 21.2 mg). Histologically, alveolar spaces were smaller and alveolar walls were thicker in the fetuses from 13‐wk‐old dams than in those from 7‐wk‐old dams. Morphometric analysis revealed that the percentage area of the fetal lung occupied by alveolar spaces was significantly smaller in the former fetuses than in the latter.

Day‐15 fetal lungs of KK mice, which do not have the Ay allele, were cultured in hyperglycemic media (glucose levels: 400 and 700 mg/dl) for 48 hr. The development of alveoli was inhibited in hyperglycemic media as compared to the development of the lungs grown in the control medium. The inhibitory effect was dependent on the glucose concentration in the media.

Thus, it seems that maternal hyperglycemia itself is a major cause of the delayed maturation of the fetal lung in NIDDM mice.
Induction of Cardiovascular Malformations by Leupeptin in the Rat
Authors: MIYATA Koichiro , KODAMA Akihiko , CHEN Shen‐Fang , TACHIKURA Toshio , OKU Shozo , YAMASAKI Takatoshi , NAKAMURA Makoto
Published: May 2008

The teratogenic effects of leupeptin on the rat embryonic heart were examined. Wistar rats were injected with 30mg/kg of leupeptin, 50mg/kg of leupeptin, and 2.5ml/kg of normal saline (control group) on days 9 and 10 of gestation. Term fetal weight was significantly lower in the leupeptin groups than in controls. At leupeptin 30mg/kg, the resorption rate, incidence of malformation, and incidence of cardiovascular (CV) malformation were 13.2%, 34.8%, 16.7%, respectively. At leupeptin 50 mg/kg, the resorption rate, incidence of malformation, and incidence of CV malformation were 19.7%, 81.4%, 36.3%, respectively. The most common malformations were hydrocephaly, anophthalmia, microphthalmia, VSD, ASD, hydronephrosis, and diaphragmatic hernia. Multiple organ systems were affected. Malformation types were similar to those induced by anti‐kidney antiserum (AKS) and trypan blue (TB).