1
|
Dass NLM, Botto LD, Tinker SC, Canfield MA, Finnell RH, Gallaway MS, Hashmi SS, Hoyt AT, Nembhard WN, Waller DK. Associations between maternal reports of periconceptional fever from miscellaneous causes and structural birth defects. Birth Defects Res 2022; 114:885-894. [PMID: 35932236 PMCID: PMC10580304 DOI: 10.1002/bdr2.2068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 05/20/2022] [Accepted: 07/15/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND Associations between birth defects and fevers attributed to colds, influenza, and urinary tract infections (UTIs) have been observed in previous studies. Our aim was to study associations between birth defects and fevers attributed to other causes. METHODS We analyzed data from 34,862 participants in the National Birth Defects Prevention Study, a multistate case-control study of major structural birth defects. Using multivariable logistic regression, we assessed the association between maternal report of fever during early pregnancy due to causes other than colds, influenza, or UTI and 36 categories of birth defects. RESULTS Maternal reports of fever due to other causes were associated with significantly elevated odds ratios ranging from 1.93 to 10.60 for 8 of 36 birth defects, primarily involving the spine, limbs, and heart (spina bifida, intestinal atresia, intercalary limb deficiency, transverse limb deficiency, congenital heart defect with heterotaxy, tetralogy of Fallot, pulmonary atresia and atrial septal defect, not otherwise specified). CONCLUSION Our data suggests fever itself or other physiologic changes associated with many infections are associated with some birth defects. Women who are pregnant or planning to become pregnant may want to consider speaking with their healthcare provider about the best ways to avoid infections that may cause fever and for guidance on how to treat fevers during pregnancy.
Collapse
Affiliation(s)
| | | | - Sarah C. Tinker
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Mark A. Canfield
- Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, Austin, Texas, USA
| | | | - Michael Shayne Gallaway
- National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Phoenix, Arizona, USA
| | | | - Adrienne T. Hoyt
- Birth Defects Epidemiology and Surveillance Branch, Texas Department of State Health Services, Austin, Texas, USA
- Department of Health and Human Performance, University of Houston, Houston, Texas, USA
| | - Wendy N. Nembhard
- University of Arkansas for Medical Sciences (UAMS), Little Rock, Arkansas, USA
| | | | | |
Collapse
|
2
|
Preliminary Evaluation of a Novel Fetal Guinea Pig Myelomeningocele Model. BIOMED RESEARCH INTERNATIONAL 2021; 2021:2180883. [PMID: 34423032 PMCID: PMC8378975 DOI: 10.1155/2021/2180883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/14/2021] [Accepted: 08/02/2021] [Indexed: 12/02/2022]
Abstract
Introduction Translational models of myelomeningocele (MMC) are needed to test novel in utero interventions. An ideal animal model for MMC has locomotor function at birth and is low cost enough to allow for high throughput. The rat MMC model is limited by immature locomotor function at birth. The ovine MMC model is a costly surgical model. Guinea pigs are uniquely suited for an MMC model being a small animal model with locomotor function at birth. We aimed to develop a retinoic acid (RA) model of MMC in the guinea pig and to evaluate if pregnant guinea pigs could tolerate uterine manipulation. Methods Time-mated Dunkin Hartley guinea pig dams were dosed with 60 mg/kg of RA between gestation age (GA) 12 and 15 days in the development of an RA model. Fetuses were grossly evaluated for MMC lesions at Cesarean section after GA 31 days. Evaluation of the ability of pregnant guinea pig dams to tolerate uterine surgical intervention was performed by hysterotomy of a separated group of time-mated guinea pigs at GA 45, 50, and 55. Results Forty-two pregnant guinea pigs were dosed with RA, with a total of 189 fetuses. The fetal demise rate was 38% (n = 71). A total of 118 fetuses were viable, 83% (n = 98) were normal fetuses, 8% (n = 10) had a neural tube defect, and 8% (n = 10) had a hematoma or other anomalies. No fetuses developed an MMC defect. None of the fetuses that underwent hysterotomy survived to term. Conclusion RA dosed at 60 mg/kg in guinea pigs between GA 12 and 15 did not result in MMC. Dunkin Hartley guinea pigs did not tolerate a hysterotomy near term in our surgical model. Further work is needed to determine if MMC can be induced in guinea pigs with alternate RA dosing.
Collapse
|
3
|
Waller DK, Hashmi SS, Hoyt AT, Duong HT, Tinker SC, Gallaway MS, Olney RS, Finnell RH, Hecht JT, Canfield MA. Maternal report of fever from cold or flu during early pregnancy and the risk for noncardiac birth defects, National Birth Defects Prevention Study, 1997-2011. Birth Defects Res 2017; 110:342-351. [PMID: 29094488 DOI: 10.1002/bdr2.1147] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 09/23/2017] [Accepted: 10/02/2017] [Indexed: 11/05/2022]
Abstract
BACKGROUND As maternal fever affects approximately 6-8% of early pregnancies, it is important to expand upon previous observations of an association between maternal fever and birth defects. METHODS We analyzed data from the National Birth Defects Prevention Study, a multistate, case-control study of major structural birth defects. Telephone interviews were completed by mothers of cases (n = 17,162) and controls (n = 10,127). Using multivariable logistic regression, we assessed the association between maternal self-report of cold or flu with fever and cold or flu without fever during early pregnancy and 30 categories of non-cardiac birth defects. RESULTS Maternal report of cold or flu with fever was significantly associated with 8 birth defects (anencephaly, spina bifida, encephalocele, cleft lip with or without cleft palate, colonic atresia/stenosis, bilateral renal agenesis/hypoplasia, limb reduction defects, and gastroschisis) with elevated adjusted odds ratios ranging from 1.2 to 3.7. Maternal report of cold or flu without fever was not associated with any of the birth defects studied. CONCLUSIONS This study adds to the evidence that maternal fever during early pregnancy is associated with an increased risk for selected birth defects. Elevated associations were limited to mothers who reported a fever, suggesting that it is fever that contributes to the excess risk rather than illnesses associated with it. However, fever may also serve as a marker for more severe infections.
Collapse
Affiliation(s)
| | | | - Adrienne T Hoyt
- Texas Department of State Health Services, Birth Defects Epidemiology and Surveillance Branch, Austin, Texas
| | - Hao T Duong
- The Partnership for Health Advancement in Vietnam (HAIVN), HCMC, Vietnam
| | - Sarah C Tinker
- National Center on Birth Defects and Developmental Disabilities, Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Michael Shayne Gallaway
- U.S. Army Public Health Command, Behavioral and Social Health Outcomes Program, Aberdeen Proving Ground, Maryland
| | - Richard S Olney
- Genetic Disease Screening Program, California Department of Public Health, Richmond, California
| | - Richard H Finnell
- Department of Pediatrics, Dell Pediatric Research Institute, The University of Texas at Austin Dell Medical School, Austin, Texas
| | | | - Mark A Canfield
- Texas Department of State Health Services, Birth Defects Epidemiology and Surveillance Branch, Austin, Texas
| | | |
Collapse
|
4
|
Omori H, Otsu M, Suzuki A, Nakayama T, Akama K, Watanabe M, Inoue N. Effects of heat shock on survival, proliferation and differentiation of mouse neural stem cells. Neurosci Res 2013; 79:13-21. [PMID: 24316183 DOI: 10.1016/j.neures.2013.11.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 11/24/2013] [Accepted: 11/27/2013] [Indexed: 01/15/2023]
Abstract
Hyperthermia during pregnancy is a significant cause of reproductive problems ranging from abortion to congenital defects of the central nervous system (CNS), including neural tube defects and microcephaly. Neural stem cells (NSCs) can proliferate and differentiate into neurons and glia, playing a key role in the formation of the CNS. Here, we examined the effects of heat shock on homogeneous proliferating NSCs derived from mouse embryonic stem cells. After heat shock at 42 °C for 20 min, the proliferating NSCs continued to proliferate, although subtle changes were observed in gene expression and cell survival and proliferation. In contrast, heat shock at 43 °C caused a variety of responses: the up-regulation of genes encoding heat shock proteins (HSP), induction of apoptosis, temporal inhibition of cell proliferation and retardation of differentiation. Finally, effects of heat shock at 44 °C were severe, with almost all cells disappearing and the remaining cells losing the capacity to proliferate and differentiate. These temperature-dependent effects of heat shock on NSCs may be valuable in elucidating the mechanisms by which hyperthermia during pregnancy causes various reproductive problems.
Collapse
Affiliation(s)
- Hiroyuki Omori
- Laboratory of Regenerative Neurosciences, Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-ogu, Arakawa-ku, Tokyo, 116-8551, Japan.
| | - Masahiro Otsu
- Department of Chemistry, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, Tokyo, 181-8611, Japan.
| | - Asami Suzuki
- Laboratory of Regenerative Neurosciences, Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-ogu, Arakawa-ku, Tokyo, 116-8551, Japan.
| | - Takashi Nakayama
- Department of Biochemistry, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
| | - Kuniko Akama
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-Cho, Inage-ku, Chiba 263-8522, Japan; Center for General Education, Chiba University, Chiba, Japan.
| | - Masaru Watanabe
- Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-ogu, Arakawa-ku, Tokyo, 116-8551, Japan.
| | - Nobuo Inoue
- Laboratory of Regenerative Neurosciences, Department of Frontier Health Sciences, Graduate School of Human Health Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-ogu, Arakawa-ku, Tokyo, 116-8551, Japan.
| |
Collapse
|
5
|
Duong HT, Shahrukh Hashmi S, Ramadhani T, Canfield MA, Scheuerle A, Kim Waller D. Maternal use of hot tub and major structural birth defects. ACTA ACUST UNITED AC 2011; 91:836-41. [PMID: 21648056 DOI: 10.1002/bdra.20831] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Revised: 03/15/2011] [Accepted: 03/19/2011] [Indexed: 12/16/2022]
Abstract
BACKGROUND Previous studies on the associations between hot tub use during early pregnancy and birth defects have found an increased risk of neural tube defects, but no increase in risk of cardiac defects. No previous studies have assessed the association between maternal hot tub use and other types of noncardiac birth defects. METHODS We included mothers of infants with birth defects (n = 10,825) and mothers of infants without birth defects (n = 6795) who participated in the multisite National Birth Defects Prevention Study between 1997 and 2005. Odds ratios were adjusted for maternal ethnicity and education. RESULTS Analysis of 17 birth defects revealed that mothers of infants with gastroschisis and anencephaly were significantly more likely to report any use of a hot tub in early pregnancy: adjusted odd ratios were 1.54 (95% confidence interval [CI], 1.10-2.17) and 1.68 (95% CI, 1.05-2.70), respectively. Among the mothers who reported using a hot tub more than once in the exposure period and remaining in it for more than 30 min, we found significantly elevated odds ratios (≥2.0) for esophageal atresia, omphalocele, and gastroschisis and a nonsignificant elevation (≥2.0) for spina bifida and anencephaly. CONCLUSIONS These results suggest that women who use hot tubs more than once during early pregnancy and for long periods of time have an increased risk of certain birth defect phenotypes, particularly anencephaly and gastroschisis. Because of multiple statistical tests and small sample sizes, we cannot exclude the possibility that some of these elevated associations may be due to chance.
Collapse
Affiliation(s)
- Hao T Duong
- The University of Texas, Houston Health Science Center, School of Public Health, USA
| | | | | | | | | | | | | |
Collapse
|
6
|
Williams D, Sullivan A. Ocular disease in the guinea pig (Cavia porcellus): a survey of 1000 animals. Vet Ophthalmol 2011; 13 Suppl:54-62. [PMID: 20840091 DOI: 10.1111/j.1463-5224.2010.00812.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
OBJECTIVE Anecdotal evidence has suggested that guinea pigs have a high prevalence of ocular lesions. Here we undertook a survey of 1000 guinea pigs from populations of animals kept as laboratory animals, breeding show cavies, animals kept as pets and those from rescue and rehoming centers. Each animal was examined to assess for ocular abnormalities. PROCEDURES A full ophthalmic examination was performed on each animal with direct and indirect ophthalmoscopy and with slit lamp biomicroscopy. Measurement of tear production using the Schirmer tear test 1 and intraocular pressure using the Tonopen applanation tonometer after topical anesthesia was undertaken in selected animals. RESULTS Forty-five percent of animals examined had some ocular abnormality. The majority were lens lesions including 17% with cataract and 21% with subclinical lens abnormalities such as nuclear sclerosis. Other abnormalities included conjunctivitis in 4.7% and keratitis in 3.6%. Lipid deposition in conjunctiva was observed in 2.3% of guinea pigs and ciliary body heterotopic bone formation in 0.8% of animals. CONCLUSIONS This study shows a high proportion of eyes with some degree of abnormality in animals otherwise considered healthy. Information on diseases of the guinea pig eye is important given the use of the species as a laboratory rodent and also the number kept as pets and show animals.
Collapse
Affiliation(s)
- David Williams
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK.
| | | |
Collapse
|
7
|
Krausova T, Peterka M. Teratogenic and lethal effects of 2–24h hyperthermia episodes on chick embryos. J Therm Biol 2007. [DOI: 10.1016/j.jtherbio.2006.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
8
|
White MG, Luca LE, Nonner D, Saleh O, Hu B, Barrett EF, Barrett JN. Cellular mechanisms of neuronal damage from hyperthermia. PROGRESS IN BRAIN RESEARCH 2007; 162:347-71. [PMID: 17645927 DOI: 10.1016/s0079-6123(06)62017-7] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Hyperthermia can cause brain damage and also exacerbate the brain damage produced by stroke and amphetamines. The developing brain is especially sensitive to hyperthermia. The severity of, and mechanisms underlying, hyperthermia-induced neuronal death depend on both temperature and duration of exposure. Severe hyperthermia can produce necrotic neuronal death. For a window of less severe heat stresses, cultured neurons exhibit a delayed death with apoptotic characteristics including cytochrome c release and caspase activation. Little is known about mechanisms of hyperthermia-induced damage upstream of these late apoptotic effects. This chapter considers several possible upstream mechanisms, drawing on both in vivo and in vitro studies of the nervous system and other tissues. Hyperthermia-induced damage in some non-neuronal cells includes endoplasmic reticular stress due to denaturing of nascent polypeptide chains, as well as nuclear and cytoskeletal damage. Evidence is presented that hyperthermia produces mitochondrial damage, including depolarization, in cultured mammalian neurons.
Collapse
Affiliation(s)
- Michael G White
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA
| | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
An episode of hyperthermia is not uncommon during pregnancy. The consequences depend on the extent of temperature elevation, its duration, and the stage of development when it occurs. Mild exposures during the preimplantation period and more severe exposures during embryonic and fetal development often result in prenatal death and abortion. Hyperthermia also causes a wide range of structural and functional defects. The central nervous system (CNS) is most at risk probably because it cannot compensate for the loss of prospective neurons by additional divisions by the surviving neuroblasts and it remains at risk at stages throughout pre- and postnatal life. In experimental animals the most common defects are of the neural tube, microphthalmia, cataract, and micrencephaly, with associated functional and behavioral problems. Defects of craniofacial development including clefts, the axial and appendicular skeleton, the body wall, teeth, and heart are also commonly found. Nearly all these defects have been found in human epidemiological studies following maternal fever or hyperthermia during pregnancy. Suggested future human studies include problems of CNS function after exposure to influenza and fever, including mental retardation, schizophrenia, autism, and cerebral palsy.
Collapse
Affiliation(s)
- Marshall J Edwards
- Faculty of Veterinary Science, The University of Sydney, Mosman, New South Wales, Australia.
| |
Collapse
|
10
|
Graham JM. Marshall J. Edwards: Discoverer of maternal hyperthermia as a human teratogen. ACTA ACUST UNITED AC 2005; 73:857-64. [PMID: 16265640 DOI: 10.1002/bdra.20185] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In a series of animal studies performed over a career spanning 40 years at the University of Sydney, Professor Marshall J. Edwards investigated the hypothesis that maternal hyperthermia during gestation can be teratogenic to the developing fetus. He is one of few investigators to have discovered a known human teratogen primarily through animal studies. In 1970 he earned his Ph.D. from the University of Sydney, writing a doctoral thesis entitled "A Study of Some Factors Affecting Fertility of Animals with Particular Reference to the Effects of Hyperthermia on Gestation and Prenatal Development of the Guinea-Pig." He went on to prove that hyperthermia-induced malformations in animals involve many organs and structures, particularly the central nervous system. Other defects include craniofacial anomalies, heart defects and hypodactyly, cataracts and coloboma, kyphoscoliosis, renal anomalies, dental agenesis, and abdominal wall defects. In a series of carefully planned and executed experiments, he demonstrated that the type of defect is related to the timing of the hyperthermic insult, and analyzed the underlying mechanisms. Cell death, membrane disruption, vascular disruption, and placental infarction were all implicated in causing embryonic damage. This special article reviews the scientific discoveries and personal philosophy of Marshall J. Edwards, the discoverer of maternal hyperthermia as a human teratogen.
Collapse
Affiliation(s)
- John M Graham
- Medical Genetics Institute, Steven Spielberg Pediatric Research Center, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
| |
Collapse
|
11
|
Abstract
Although maternal fever has been implicated as a human teratogen in several studies, no prospective study has adequately addressed the full spectrum of birth outcomes following such exposure in pregnancy. The purpose of this study was to determine whether or not maternal fever is associated with an increased risk for structural malformations, prematurity, growth retardation, or pregnancy loss. Using a prospective cohort study design, we ascertained women who had called the California Teratogen Information Service and Clinical Research Program between 1979-1996 with questions regarding fever in a current pregnancy. Of these women, 115 who reported a fever of at least 38.9 degrees C lasting for at least 24 h (high fever group) and 147 women who reported a fever of either less than 38.9 degrees C or lasting less than 24 h (low fever group) were enrolled in the cohort. An additional 298 pregnant women who reported having no fever at any time in pregnancy were enrolled in a control group. All pregnancies were followed in a similar fashion, and outcomes were compared among the three groups. The combined prevalence of all major structural malformations was increased, but not significantly so, in the offspring of women who had a high fever in the first trimester of pregnancy compared to those with a lower fever or to controls (relative risk 1.80 for high fever group compared to controls; 95% confidence interval, 0.54, 6.03; relative risk 1.21 for low fever group compared to controls; 95% confidence interval, 0.36, 4.03). However, 2/34 or 5.9% of women who had a high fever during the critical period for neural tube closure carried fetuses with anencephaly compared to none in the low fever group or controls. Specific minor defects were found more frequently in the high fever group compared to controls and were consistent with the pattern of defects previously reported in a retrospective case series. In addition, stillbirth occurred more frequently in the high fever group compared to controls (2.6% vs. 0%). These data support the conclusion that high maternal fever early in pregnancy is a human teratogen. Women who experience fevers of 38.9 degrees C or higher for extended periods of time in the first month of pregnancy should be considered at increased risk for neural tube defects and should be provided appropriate counseling.
Collapse
Affiliation(s)
- C D Chambers
- Department of Pediatrics, University of California at San Diego, La Jolla 92103, USA
| | | | | | | | | |
Collapse
|
12
|
Graham JM, Edwards MJ, Edwards MJ. Teratogen update: gestational effects of maternal hyperthermia due to febrile illnesses and resultant patterns of defects in humans. TERATOLOGY 1998; 58:209-21. [PMID: 9839360 DOI: 10.1002/(sici)1096-9926(199811)58:5<209::aid-tera8>3.0.co;2-q] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
This review has covered the pertinent literature concerning the teratogenic effects of hyperthermia in man and experimental animals. This is the first teratogen that was initially discovered in animals and then subsequently found to be a cause for concern in humans when similar patterns of defects were observed. Hyperthermia is a physical agent with a dose-response curve for abortions and malformations, but these effects can be mitigated in some circumstances by the heat shock response (HSR). We have reviewed the known functions of HSR and provided some insight into why embryos have some protection following an initial dose of heat, if it is sufficient to initiate the response. Thus, by reviewing the effects of hyperthermia in experimental animals, as well as malformative and protective mechanisms of teratogenesis, we have attempted to understand the effects of human hyperthermia teratogenesis.
Collapse
Affiliation(s)
- J M Graham
- Medical Genetics Birth Defects Center, UCLA School of Medicine, Cedars-Sinai Medical Center, USA.
| | | | | |
Collapse
|
13
|
Peterka M, Peterková R, Likovský Z. Teratogenic and lethal effects of long-term hyperthermia and hypothermia in the chick embryo. Reprod Toxicol 1996; 10:327-32. [PMID: 8829256 DOI: 10.1016/0890-6238(96)00062-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The teratogenic effect of maternal hyperthermia is well known in laboratory animals and is presumed to exist also in humans. The aim of our study was to describe the embryotoxic effect of long-term higher and lower incubation temperatures on the chick embryo. Chick embryos were incubated within days 1 to 9 at 12 different incubation temperatures ranging from 31 to 42 degrees C. On the basis of our results, we estimated that there are three upper and lower critical thresholds of the incubation temperature: the first thresholds are 31 and 42 degrees C, at which all embryos died; the second thresholds are 32 and 41 degrees C, at which all living embryos were malformed; the third thresholds are 33 and 40 degrees C, at which some of the living embryos were without structural malformations, but their weight was shifted down and up with lower and higher temperature, respectively. The incubation temperature of 37 to 38 degrees C was optimal. Typical malformations detected on day 9 of incubation were microphthalmia, gastroschisis, caudal regression syndrome, and hyperlordosis, all of which occurred in dead embryos several times more frequently than in living embryos. CNS malformations were only sporadically present on day 9, as most of specimens bearing CNS defects died during the first days of incubation.
Collapse
Affiliation(s)
- M Peterka
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | | |
Collapse
|
14
|
Smith MS, Upfold JB, Shiota K. Neural tube defects in the parietal region of human embryos: failure to close or closure-reopening? Neuropathol Appl Neurobiol 1993; 19:66-73. [PMID: 8474602 DOI: 10.1111/j.1365-2990.1993.tb00406.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
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.
Collapse
Affiliation(s)
- M S Smith
- School of Anatomy, University of New South Wales, Australia
| | | | | |
Collapse
|