Background and Objective: Type 2 (T2DM) and gestational diabetes mellitus (GDM) among pregnant Filipinos have been increasing over the years because of lifestyle westernization. While insulin has been the safe mainstay when dietary measures fail to maintain normoglycemia during pregnancy, recent studies have suggested oral hypoglycemic agents (OHAs) such as metformin and glibenclamide, may offer cheaper and efficacious alternatives. The problem however, is the passage of these drugs through the placenta which may pose possible danger towards the development of the growing embryo. The proposed study aims to evaluate and compare the embryotoxic and teratogenic potentials of the varying concentrations of the two PhilHealth covered oral hypoglycemic agents in the Philippines, namely metformin (biguanide) and glibenclamide (sulfonylureas). Methodology: In this study, a comparison on embryotoxic potentials of metformin and glibenclamide was conducted using zebrafish embryotoxicity test (ZFET) across concentrations found in fetal (10, 20, 100, 500, 1000, 2000 μg/L) and maternal serum (10, 20, 100, 500, 1000, 2000 mg/L). Results and Conclusions Results revealed that metformin showed no significant (p>0.05) lethal effects, but revealed significant risk for teratogenicity, specifically decreased head and tail lengths and advanced hatching. Conversely, glibenclamide revealed significant potential for lethal (e.g., coagulation) and teratogenic effects including pericardial and yolk sac edema, spinal deformity and increased tail length. Comparative evaluation between the two OHAs reveal that glibenclamide has significantly (p<0.05) higher lethal and teratogenic effects. Together, our results suggest that the use of metformin over glibenclamide is favorable for safety testing in pregnant women suffering T2DM and GDM for the benefit of expanding treatment options for these diseases.
Glyburide ; Metformin ; Teratogenesis ; Zebrafish

X -ray irradiation induces various congenital anomalies in the human fetuses and experimental animals. The action mechanism of teratogenesis, however, still not known completely. Furthermore, the dynamics of teratogenesis according to the developmental stages are so great that complete unveiling the teratogenic action mechanism of radiation is nearly impossible. And, it is necessary to make the experimental model for the study on the damages caused by electromagnetic field, recently. In this study, the Sprague -Dawley rats were irradiated 2 Gy once on the GD 10.7, and observed the congenital anomalies of the fetuses on GD 17.5, grossly and light microscopically. The results were as follows ; 1. There was no significant difference in the survival rate between control and irradiated groups. However, mean body weight of the experimental group decreased significantly compared to control group. 2. X -irradiation -induced congenital anomalies were eye anomalies such as unilateral and/or bilateral anophthalmia, microphthalmia, and aphakia, hemorrhagic plaques on the head, tail anomalies such as short tail and curved tail, and posterior limb anomalies. 3. Posterior limb anomalies were all ecrodactyly, such as 4 -digit anomaly, 3 -digit anomaly, and cleft foot. In the sidedness of anomalies, right side showed greater dominance than left.
Animals ; Anophthalmos ; Aphakia ; Body Weight ; Electromagnetic Fields ; Extremities ; Fetus* ; Foot ; Head ; Humans ; Microphthalmos ; Models, Theoretical ; Rats* ; Survival Rate ; Tail ; Teratogenesis

Retinoic acid(RA), formed in vivo by oxidation of retinol, is known as morphogenic signal. RA plays an active role in normal embryonic development at physiological concentration, but excess RA can be a powerful teratogen in human and animals. The present study was designed to examine the direct effect of RA on murine embryogenesis(gastrulation) and to define the specific development processes perturbed by RA. Five to fifteen blastocysts were randomly assigned to separate culture dishes of the experimental group. Various concentrations of RA(10(-9) M, 10(-7) M, and 10(-5) M) were used in culturing blastocysts. In the effect of RA on the normal grouwth of embryo, the rates of development to the stages of attachment, early egg cylinder(EEC), late egg cylinder(LEC), and early somite(ES)were significantly(p < 0.01) decreased as the RA concentration increased. Stil in the yolk sac formation rate, there was a significant, dose-dependent difference(p < 0.01) according to the RA concentration. In the degeneration of embryos by RA, the effect was more apparent as the concentration of Ra increased. The production rates of embryos devoid of egg cylinder region and embryos with abnormal egg cylinder region were increased (p < 0.01)in a dose-dependent manner according to RA concentration. In conclusion, RA probably act as teratogen at gastrula stage embryos in high concentration and effect of teratogenesis is dose-dependent.
Animals ; Blastocyst ; Embryonic Development ; Embryonic Structures ; Female ; Gastrula ; Gastrulation* ; Humans ; Mice* ; Ovum ; Pregnancy ; Teratogenesis ; Tretinoin* ; Vitamin A ; Yolk Sac

In the development of tooth, the first sign is the localized thickening of oral ectoderm to form the tooth bud, and then through the dialogue between the bud and underlying mesenchyme, proliferation and differentiation of bud cells and surrounding mesenchymal cells continue, and cap and bell stages follow. In each step of development, various teratogens may act directly and indirectly, and may result a certain congenital anomalies. To reveal the action mechanism of ionizing radiation on odontogenesis morphologically, 4 Gy X-ray irradiated on the rat (Sprague-Dawley strain) fetus on GD 12.7, and observed the histological changes of the upper incisor tooth from GD 13.5 to GD 20.5, daily. In the normal development of upper incisor tooth of rat, the bud stage was from GD 12.5 ~GD 15.5, the cap stage was from GD 16.5 to GD 17.5, and the bell stage was GD 18.5 to GD 20.5. After X-irradiation on GD 12.7, the development of incisor tooth was delayed markedly, the bud stage was prolonged from GD 13.5 to GD 17.5, and the cap stage was GD 18.5 and the bell stage was from GD 19.5 to GD 20.5. After X-irradiation, from GD 13.5 to GD 16.5, apoptosis is observed in the dental organ and surrounding mesenchyme, hemorrhagic necrosis began from GD 16.5 at the center of dental pulp, followed ischemic necrosis of dental organ and surrounding mesenchyme. After GD 19.5, the development of tooth was ceased. These suggest that at least 2 mechanisms involved during X-ray teratogenesis on developing tooth. After X-irradiation on GD 12.7, initially, X-ray induced apoptosis of the cells of dental lamina and dental bud, which resulted the delayed proliferation and differentiation of dental bud and shortage of the number of cells having signal molecules which induce aggregation of the underlying mesenchymal cells. Lately, disorganization of the endothelial cells differentiated from the damaged mesenchymal cells, which resulted in rupture of capillaries and the hemorrhagic necrosis.
Animals ; Apoptosis ; Capillaries ; Dental Pulp ; Ectoderm ; Endothelial Cells ; Fetus ; Incisor* ; Mesoderm ; Necrosis ; Odontogenesis ; Radiation, Ionizing ; Rats* ; Rupture ; Teratogenesis ; Teratogens ; Tooth*

For the study on the teratogenic effects and its mechanism of FUDR on the developing rat fetuses, Sprague -Dawley rats as experimental animal and 5 -fluoro -2 '-deoxyuridine (Sigma chemicals) as FUDR were used respectively. On the day of gestation 10.5, 60 mg/kg, 65 mg/kg and 70 mg/kg of FUDR was injected intraperitoneally, and sacrificed under ether anesthesia on the day of gestation 17.5. External congenital malformations such as hydrocephalus, lens defect, cleft palate, short tail, forelimb and hindlimb malformations were observed under stereoscope, and compared each other with control group. The results were as follows; 1. Congenital anomalies induced by FUDR were hydrocephalus, lens defect, cleft palate, short tail, and defects of extremities such as phocomelia, loss of first and second digits, undergrowth of digits, and syndactyly. 2. There is close relation between the rate of occurance of congenital anomalies and doses of FUDR in some organs. 3. There is significant differences between forelimbs and hindlimbs and between right forelimb and left forelimb in the rate of occurance of congenital anomalies of the extremities. According to the above results, it is considered that there is significant differences between the types and occurance rates of congenital anomalies induced by FUDR and the doses of FUDR. But distinct mechanism of action during teratogenesis of FUDR still remains unclear.
Anesthesia ; Animals ; Cleft Palate ; Ectromelia ; Ether ; Extremities ; Fetus ; Floxuridine* ; Forelimb ; Hindlimb ; Hydrocephalus ; Pregnancy ; Rats* ; Syndactyly ; Tail ; Teratogenesis

Diastematomyelia, a form of spinal dysraphism, is characterized by a division of the spinal cord or canda equina resulting the form a bony or cartilaginous spur which transfixes the neural elements and dura. The presence of a structure of neural crest origin in the subarachnoid space connecting the spicules suggested that the anomaly resulted from delayed closure of the neural tube and its investments. The cinical finding are presumed due to its restriction, tethering of the normal apward migration of the spinal cord. Congenital anomalies of one or both lower extremities and spine are frequently found with this condition. The surgical removal is recommended as a prophylactic measure against further progressive neurological damage. The purpose of this paper is to presented becanse it was associated with clubfoot and adds to understanding of teratogenesis of diastematomyelia.
Clubfoot ; Investments ; Lower Extremity ; Neural Crest ; Neural Tube ; Neural Tube Defects ; Spinal Cord ; Spinal Dysraphism ; Spine ; Subarachnoid Space ; Teratogenesis

OBJECTIVE: The animal research of embryonic teratogenesis is widely performed and the neural tube defects are also studied through various animal models. Particularly, the experimental research on chick embryos is performed with great popularity. In this experiment we studied the effect of albumen removal and the needle puncture on the development of neural tube defects in chick embryos. METHODS: The domestic hen eggs of control group are incubated for 14 days at 37.5degreesC and 70% humidity. The experimental group was divided into three groups, needle puncture group, 5 cc albumen removal group and 10 cc albumen removal group after the eggs were incubated for 24-28 hours and incubated for another 13 days after the puncture with or without albumen removal. After 14 days of incubation, all the embryos were isolated and morphologically characterized. RESULTS: Of 39 incubated chick embryos in control group, 31 embryos were grown as normal and 8 embryos were grown as anomalous. The numbers of total(normal/anomalous/developmentally arrest) embryos of each group were 37(14/16/7), 37(9/17/11), and 37(6/13/18) in the needle puncture, 5cc albumen removal and 10cc albumen removal groups, respectively. Needle puncture increased the teratogenesis of chick embryos significantly but did not increase the neural tube defect. In cases of 5 cc albumen removal, the teratogenesis of chick embryos was increased to a significant level and the incidence of neural tube defect was increased significantly. In cases of 10 cc albumen removal, not only teratogenesis but also growth arrest were increased markedly. Therefore, it was not considered to be an adequate experimental model. CONCLUSIONS: This results indicate that needle puncture itself to remove the albumen from chick embryos had nothing to do with the neural tube defects and therefore its effect can be excluded. Needle puncture and albumen removal cause not only neural tube defects but other malformations such as abdominal wall defects, developmental arrest, and malformation of eyes.
Abdominal Wall ; Animal Experimentation ; Animals ; Chick Embryo* ; Eggs ; Embryonic Structures ; Humidity ; Incidence ; Models, Animal ; Models, Theoretical ; Needles* ; Neural Tube Defects* ; Neural Tube* ; Ovum ; Punctures* ; Teratogenesis

PURPOSE: Retinoic acid (RA) is well known as a potent teratogenic agent in both deficiency and excess. Cellular retinoic acid binding proteins (CRABPs) are involved in RA. We carried this study in order to determine the possible relations of CRABPs with RA-induced teratogenesis through observation of the expression patterns of CRABP l and ll in developing rats. METHODS: 35S-labeled RNA probes were synthesized using SP6-RNA polymerase in CRABP l and T7-polymerase in CRABP ll. The distribution of CRABP l and ll transcripts analyzed by in situ hybridization of rat embryosections from day 12 to 19, and postnatal brains from day 1 to 14. RESULTS: The CRABP ll transcripts were more widely distributed than CRABPl distribution, however, the relative level of CRABPl transcripts were higher than CRABP ll. The CRABP l mRNA transcripts showed its highest expression on the 16th day of gestation and these distribution correlated well with structures known to be targets of RA-induced teratogenesis. CRABP ll transcripts were expressed in brain vesicle, spinal cord, head, face, tongue and genital tubercle and also found in the structures which are not involved in RA-induced teratogenesis. CONCLUSION: These results suggest the possible involvement of both CRABPs in the RA-induced teratogenesis. However, CRABP l may have more specific roles than CRABP ll which may play a role through a different mechanism.
Animals ; Brain ; Carrier Proteins* ; Head ; In Situ Hybridization ; Pregnancy ; Rats* ; Receptors, Retinoic Acid ; RNA Probes ; RNA, Messenger* ; Spinal Cord ; Teratogenesis ; Tongue ; Tretinoin*

BACKGROUND: Trisomy 16 in mice is considered to be an animal model for Down's syndrome in human. We studied the morphologic characteristics of the heart and the edema, and their significance to the teratogenesis in this animal model. METHODS: A total of 30 dams were sacrificed to bear 125 (61.9%) normal fetuses 35 (17.3%) abnormal fetuses and 42 (20.8%) resorptions. Cytogenetic study and morphological examination were performed using microdissection agar-mount sectioning histologic examination and scanning electron microscope. RESULTS: The crown-rump length was significantly shorter in abnormal (trisomic fetuses) than the normal (eusomic) fetuses. Trisomic fetuses showed massive edema at the back from the vertex to the lumbar area. Four-chamber view section of the agar-mount and histologic section showed a common atrioventricular valve bridging the left and the right atrioventricular junction. Scanning electron microscopic examination on atrioventricular valves showed three types of atrioventricular valves:five cases with common atrioventricular orifice, three cases with partitioned atrioventricular orifice and two cases with atresia of the right atrioventricular orifice. CONCLUSION: This study confirmed the presence of massive edema and cardiac anomalies in the mouse with trisomy 16. But there was morphologic diversity of cardiac anomaly in this model.
Animals ; Crown-Rump Length ; Cytogenetics ; Down Syndrome ; Edema* ; Endocardial Cushion Defects ; Fetus* ; Heart ; Humans ; Hydrops Fetalis ; Mice ; Microdissection ; Models, Animal ; Pathology* ; Teratogenesis ; Trisomy*

The increasing uses of zinc oxide nanoparticles (nZnO) in industrial and personal care products raise possible danger of using nZnO in human. To determine whether ZnO induces size-dependent anomalies during embryonic organogenesis, mouse embryos on embryonic day 8.5 were cultured for 2 days under 50, 100, and 150 microg of nZnO (< 100 nm) or micro-sized ZnO (mZnO; 80 +/- 25 microm), after which the morphological changes, cumulative quantity of Zn particles, and expressions of antioxidant and apoptotic genes were investigated. Although embryos exposed to 50 microg of ZnO exhibited no defects on organogenesis, embryos exposed to over 100 microg of ZnO showed increasing anomalies. Embryos treated with 150 microg of nZnO revealed significant changes in Zn absorption level and morphological parameters including yolk sac diameter, head length, flexion, hindbrain, forebrain, branchial bars, maxillary process, mandibular process, forelimb, and total score compared to the same dose of mZnO-treated embryos. Furthermore, CuZn-superoxide dismutase, cytoplasmic glutathione peroxidase (GPx) and phospholipid hydroperoxidase GPx mRNA levels were significantly decreased, but caspase-3 mRNA level was greatly increased in nZnO-treated embryos as compared to normal control embryos. These findings indicate that nZnO has severer teratogenic effects than mZnO in developing embryos.
Absorption ; Animals ; Caspase 3 ; Cytoplasm ; Embryonic Structures* ; Forelimb ; Glutathione Peroxidase ; Head ; Humans ; Mice* ; Nanoparticles ; Organogenesis ; Prosencephalon ; Rhombencephalon ; RNA, Messenger ; Teratogenesis ; Yolk Sac ; Zinc Oxide*