Sex-related differences in procarbazine-induced cleft palate and microgenia and the anti-teratogenic effect of prenatal folic acid supplementation in rats

The Soft Tissue Angular Analysis of Facial Profile in Unoperated Adult Patients with Unilateral Cleft Palate

OBJECTIVE

The purpose of this study was to investigate the differences in facial profile development between unoperated adult cleft palate (UACP) patients and normal controls and to analyse the reasons for the differences.

MATERIALS AND METHODS

A total of 50 individuals with a unilateral cleft palate and 20 normal controls were selected to undergo angular measurement of their facial profiles. Data with significant differences between the two groups were analysed.

RESULTS

Seven angle measurements of the facial profile showed that the mid-facial protrusion of the UACP patients had no significant differences from the control group (p > 0.05). But their angle of the medium face (N'-Trg-Sn) was significantly lower than the non-cleft controls (p < 0.05), suggesting a worse vertical development of the middle face. A significantly larger nasal tip angle (Cm-Sn/N'-Prn) for UACP patients suggested they had a rounder and blunter nasal tip (p < 0.05). The soft tissue facial angle and chin-lip angle of UACP patients had significant differences from non-cleft controls (p < 0.05), but the head position angle (Sn-Sm-THP) had no significant difference between two groups (p > 0.05), which suggested a steep mandibular plane for UACP patients but without severe retraction of the chin.

CONCLUSION

The development of facial protrusions in UACP patients is similar to that in normal adults, but the vertical development in the middle face is insufficient. Such hypoplasia may be related to the intrinsic deficiency of the maxilla. There is a tendency for flat nasal growth and insufficient development of the chin in UACP patients.

LEVEL OF EVIDENCE IV

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Oral vitamin B1-substitution does not decrease genetically determined cleft rate in mice (A/WySn)

PURPOSE

Cleft lip and palate (CL/P) are one of the most common human birth defects. Animal experiments and clinical investigations show a clear reduction of teratogenic clefts by a high-dose vitamin B supplementation during early pregnancy, especially in families at risk (reduction of recurrence). The aim of this work was to examine the influence of thiamine (vitamin B1) on CL/P appearance in genetically determined A/WySn mice within different supplementation starting points.

MATERIALS AND METHODS

A total of 24 A/WySn female mice were orally supplemented with high doses (80 mg/kg) of thiamine at different times of pregnancy (5 groups, n = 90). The influence of thiamine on the abortion rate and CL/P appearance in the offspring was analyzed with respect to the concentration of thiamine in the serum and amniotic fluid (HPLC-chromatography). Immunochemical analyses of the ThTr-1 und ThTr-2 receptor-status were performed in midface sections of A/WySn-fetuses and the corresponding placenta, with and without CL/P.

RESULTS

High doses of orally supplemented thiamine did not reduce the CL/P appearance in A/WySn mice. However, the different starting points of vitamin B1 substitution had some influence. Additionally, an obvious decrease in aborted fetuses was noticed in all supplemented groups. The oral substitution caused a clear increase of the serum concentration in all mothers, but showed no increase of the amniotic fluid concentration. Then immunohistochemistry detected an overexpression of ThTr-1 in the midface and an irregular localization of ThTr-2 in the placenta of fetuses with clefts.

CONCLUSION

Our results suggest a time-dependent influence of thiamine on CL/P appearance in female mice. The prophylactic/periconceptional, but not the therapeutic supplementation, starting point can be proposed as a crucial step for regular facial and palatal fusion in embryonic development. The absolute rate of CL/P was not reduced, and the concentration of the water-soluble thiamine could not increase in the amniotic fluid. Thus the proposed local effect of thiamine failed in the development of genetically determined mice.

Sex distribution is a factor in teratogenically induced clefts and in the anti-teratogenic effect of thiamine in mice, but not in genetically determined cleft appearance

PURPOSE

Cleft lip and/or palate (CL/P) shows a gender-related distribution in human beings. The reason is unknown. This study analyzed the gender-related cleft appearance with respect to teratogenically and genetically determined cleft appearance and the response to thiamine (vitamin B1) supplementation.

MATERIAL AND METHODS

Cyclophosphamide (CPA; 0.6 mg) and dexamethasone (0.25 mg) were injected intraperitoneally to A/B-Jena mice on different days of pregnancy. The abortion and malformation rate in the A/B-Jena and A/WySn mice with genetically determined clefting was documented to be gender-specific. Vitamin B1 was given to A/B-Jena dams at different times during pregnancy before, simultaneously and after the teratogenic agent was given to the pregnant mothers. A/WySn mice received oral supplementation at different times during embryonic/fetal development.

RESULTS

There were significantly more living female fetuses when mothers were treated with teratogens, and the embryo lethality and malformation affected more male individuals. However, the survival and malformation rate in A/WySn mice was not gender-specific. Especially in male fetuses, vitamin B1 decreased the teratogenic cleft rate (CPA: p < 0.001, dexamethasone: p = 0.6), whereas there was no effect in the A/WySn mice.

CONCLUSION

There was a strong anti-teratogenic effect of vitamin B1, especially in the male fetuses. Genetically determined cleft appearance was not positively influenced. These findings confirm observations about cleft appearance in human beings.

Oral cleft prevention program (OCPP)

Background

Oral clefts are one of the most common birth defects with significant medical, psychosocial, and economic ramifications. Oral clefts have a complex etiology with genetic and environmental risk factors. There are suggestive results for decreased risks of cleft occurrence and recurrence with folic acid supplements taken at preconception and during pregnancy with a stronger evidence for higher than lower doses in preventing recurrence. Yet previous studies have suffered from considerable design limitations particularly non-randomization into treatment. There is also well-documented effectiveness for folic acid in preventing neural tube defect occurrence at 0.4 mg and recurrence with 4 mg. Given the substantial burden of clefting on the individual and the family and the supportive data for the effectiveness of folic acid supplementation as well as its low cost, a randomized clinical trial of the effectiveness of high versus low dose folic acid for prevention of cleft recurrence is warranted.

Methods/design

This study will assess the effect of 4 mg and 0.4 mg doses of folic acid, taken on a daily basis during preconception and up to 3 months of pregnancy by women who are at risk of having a child with nonsyndromic cleft lip with/without palate (NSCL/P), on the recurrence of NSCL/P. The total sample will include about 6,000 women (that either have NSCL/P or that have at least one child with NSCL/P) randomly assigned to the 4 mg and the 0.4 mg folic acid study groups. The study will also compare the recurrence rates of NSCL/P in the total sample of subjects, as well as the two study groups (4mg, 0.4 mg) to that of a historical control group.

The study has been approved by IRBs (ethics committees) of all involved sites. Results will be disseminated through publications and presentations at scientific meetings.

Discussion

The costs related to oral clefts are high, including long term psychological and socio-economic effects. This study provides an opportunity for huge savings in not only money but the overall quality of life. This may help establish more specific clinical guidelines for oral cleft prevention so that the intervention can be better tailored for at-risk women.

ClinicalTrials.gov Identifier

NCT00397917

Folic acid and orofacial clefts: a review of the evidence

Orofacial clefts are common and burdensome birth defects with a complex genetic and environmental etiology. The contribution of nutritional factors and supplements to the etiology of orofacial clefts has long been theorized and studied. Multiple studies have evaluated the role of folic acid in the occurrence and recurrence of orofacial clefts, using observational and non-randomized interventional designs. While preventive effects of folic acid on orofacial clefts are commonly reported, the evidence remains generally inconsistent. This paper reviews the findings of the main studies of the effects of folic acid on orofacial clefts, summarizes study limitations, and discusses research needs with a focus on studying the effects of high dosage folic acid on the recurrence of oral clefts using a randomized clinical trial design. The role of folic acid in the prevention of neural tube defects is also briefly summarized and discussed as a reference model for orofacial clefts.

Folic acid administration prevents ouabain-induced hyperlocomotion and alterations in oxidative stress markers in the rat brain

OBJECTIVE

Bipolar disorder (BD) is a chronic, prevalent, and highly debilitating psychiatric illness. Folic acid has been shown to have antidepressant-like effects in preclinical and clinical studies and has also been suggested to play a role in BD. The present work investigates the therapeutic value of folic acid supplementation in a preclinical animal model of mania induced by ouabain.

METHODS

Male Wistar rats were treated twice daily for seven days with folic acid (10, 50, and 100 mg/kg, p.o.) or the mood stabilizer lithium chloride (LiCl) (45 mg/kg, p.o.). One day after the last dose was given, the animals received an i.c.v. injection of ouabain (10 microM), a Na(+),K(+)-ATPase-inhibiting compound. Locomotor activity was assessed in the open-field test. Thiobarbituric acid-reactive substance (TBARS) levels, glutathione peroxidase (GPx), and glutathione reductase (GR) activities were measured in the cerebral cortex and hippocampus.

RESULTS

Ouabain (10 microM, i.c.v.) significantly increased motor activity in the open-field test, and seven days of pretreatment with folic acid (50 mg/kg, p.o.) or LiCl (45 mg/kg, p.o.) completely prevented this effect. Ouabain treatment elicited lipid peroxidation (increased TBARS levels) and reduced GPx activity in the hippocampus. GR activity was decreased in the cerebral cortex and hippocampus. These effects were prevented by pretreatment with folic acid and LiCl.

CONCLUSIONS

Our results show that folic acid, similarly to LiCl, produces a clear antimanic action and prevents the neurochemical alterations indicative of oxidative stress in an animal model of mania.

Sexing of postimplantation rat embryos in stored two-dimensional electrophoresis (2-DE) samples by polymerase chain reaction (PCR) of an Sry sequence

Proteomic analysis of developmental toxicity by two-dimensional electrophoresis (2-DE) may detect gender-related toxic effects in embryos without visible gender characteristics. In the present study, we explored sexing of rat embryo stored in frozen 2-DE samples by polymerase chain reaction (PCR) of a male-specific gene sequence, sex determining region Y (Sry). The embryo proper and yolk sac membrane at gestation day 11 from Wistar rats were used for stored embryonic 2-DE samples. The embryonic 2-DE samples were desalted and their total DNA was extracted. The Sry sequence in the extracted DNA was amplified by PCR and the product was analyzed by agarose gel electrophoresis. The embryos with the PCR product of Sry were determined as male, and those without the product were determined as female. It was concluded that stored embryonic 2-DE samples could be used for retrospective examination of gender-related effects in proteomic analysis of developmental toxicity.

Risk factors for oral clefts: a population-based case-control study in Shenyang, China

Shenyang in Northern China has one of the highest reported prevalence rates of oral clefts in the world. To explore the risk factors for oral clefts in Shenyang, we carried out a population-based case-control study. A total of 360 990 births in 2000 to 2007 were screened for oral clefts; the overall prevalence was 1.76 per 1000. The ratio of cleft lip with or without cleft palate (CL +/- P) : cleft palate only (CP) was 5.60:1. The overall male : female ratio was 2.02:1. CLP and CL were more common in males than in females with a sex ratio (SR) of 2.88:1 and 1.86:1 respectively, whereas CP was more common in females with an SR of 0.71:1. Using a multivariable conditional logistic regression model, 586 oral clefts cases were compared with 1172 control mothers. Maternal factors significantly associated with increased risk for oral clefts were history of a fever or cold (adjusted OR 2.34, 95% CI 1.06, 5.60); use of analgesic and antipyretic drugs (adjusted OR 3.10, 95% CI 1.41, 6.86); poor ventilation during heating (adjusted OR 2.25, 95% CI 1.10, 4.60); and consumption of pickled vegetables >6 per week (adjusted OR 3.86, 95% CI 1.11, 13.47) during pregnancy. Factors which appeared to be protective were meat consumption >or=4 times per week (adjusted OR 0.43, 95% CI 0.28, 0.67); and legume consumption >6 times per week (adjusted OR 0.60, 95% CI 0.41, 0.89). Differences in risk were found between the two most common phenotypes, CL +/- P and CP only. Most of the environmental factors had stronger associations with risk for CL +/- P rather than CP, whereas history of oral clefts, as well as legume consumption, were more strongly associated with the risk for CP than for CL +/- P. The findings suggest that aetiological heterogeneity may exist between CL +/- P and CP.

Congenital fenestration of the palate: A case of embryologic syzygy

Congenital fenestration of the secondary palate is the rarest type of facial cleft. Of the 26 putative cases in the literature, only 5 had confirmation of the cleft during the neonatal period. This report documents such a cleft in an infant and presents the likely pathogenesis.

Reduction of procarbazine-induced cleft palates by prenatal folic acid supplementation in rats

We investigated the effects of prenatal folic acid supplementation on procarbazine (PCZ)-induced intra-uterine growth retardation (IUGR), cleft palates, and microgenia. Three groups of gravid rats were treated with 200 mg/kg body weight (BW) PCZ on day 13.5 of gestation (GD13.5). Two groups of them were additionally supplemented with 1 and 2.5 mg/kg folic acid, respectively, from GD13.5 through GD16.5. On GD19.5, all fetuses were delivered by caesarian sections and sexed subsequently. Numbers of live and dead fetuses as well as resorptions were counted. Data on fetal BW, crown-rump length, tail length, placental weight, and diameter were collected. Fetal heads were histologically scrutinized for the occurrence of cleft palates and microgenia. Folic acid at 2.5 mg/kg diminished PCZ-induced IUGR. In male fetuses, both folic acid doses significantly reduced the incidence of cleft palates and microgenia, while in females, only the high folic acid dose was capable of lowering the occurrence frequency of cleft palates. We conclude that folic acid supplementation at the used doses confers a substantial protection against PCZ-induced IUGR and incidence of cleft palates and microgenia. However, these effects are gender-related and dose-dependent.