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Biomedical subjects

C A Moore

Publications and source records attributed to C A Moore.

At least 37 records · Page 2Linked to original sources

Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention.

BACKGROUND AND METHODS: Periconceptional administration of folic acid can reduce a woman's risk of having a fetus or infant with a neural-tube defect. As part of a public health campaign conducted from 1993 to 1995 in an area of China with high rates of neural-tube defects (the northern region) and one with low rates (the southern region), we evaluated the outcomes of pregnancy in women who were asked to take a pill containing 400 microg of folic acid alone daily from the time of their premarital examination until the end of their first trimester of pregnancy. RESULTS: Among the fetuses or infants of 130,142 women who took folic acid at any time before or during pregnancy and 117,689 women who had not taken folic acid, we identified 102 and 173, respectively, with neural-tube defects. Among the fetuses or infants of women who registered before their last menstrual period and who did not take any folic acid, the rates of neural-tube defects were 4.8 per 1000 pregnancies of at least 20 weeks' gestation in the northern region and 1.0 per 1000 in the southern region. Among the fetuses or infants of the women with periconceptional use of folic acid, the rates were 1.0 per 1000 in the northern region and 0.6 per 1000 in the southern region. The greatest reduction in risk occurred among the fetuses or infants of a subgroup of women in the northern region with periconceptional use who took folic acid pills more than 80 percent of the time (reduction in risk, 85 percent as compared with the fetuses or infants of women who registered before their last menstrual period and who took no folic acid; 95 percent confidence interval, 62 to 94 percent) [corrected]. In the southern region the reduction in risk among the fetuses or infants of women with periconceptional use of folic acid was also significant (reduction in risk, 41 percent; 95 percent confidence interval, 3 to 64 percent). CONCLUSIONS: Periconceptional intake of 400 microg of folic acid daily can reduce the risk of neural-tube defects in areas with high rates of these defects and in areas with low rates.

Adult↗

Mild autosomal dominant hypophosphatasia: in utero presentation in two families.

We describe four pregnancies in two families in which mild hypophosphatasia, apparently transmitted as an autosomal dominant trait, manifested in utero as severe long bone bowing. Postnatally, there was spontaneous improvement of the skeletal defects. Recognition of this presentation for hypophosphatasia by family investigation and assessment of the fetal skeleton for degree of ossification and chest size using ultrasonography is important. The prognosis for this condition is considerably better than for more severe forms of hypophosphatasia and for many other disorders that cause skeletal defects with long bone bowing in utero.

Adult↗

Tibial hemimelia in Langer-Giedion syndrome-possible gene location for tibial hemimelia at 8q.

We report on a girl with Langer-Giedion syndrome or tricho-rhino-phalangeal syndrome, type II (TRPS II) with deletion on 8q, and the unusual findings of bilateral tibial hemimelia and unilateral absence of the ulna. An 8-year-old boy with TRPS II with bilateral tibial hemimelia was reported by Turleau et al. [1982: Hum. Genet. 62:183-187]. The critical region for TRPS II is 8q24.1. Although no genes involving limb development in the human have been identified in this region, two mouse syndromes are localized to the homologous chromosome region of 9A1-A4 which involve limb abnormalities. We propose that a gene involved in limb development is contiguous with the TRPS II gene which, when deleted, may cause tibial hemimelia.

Arm↗

Nausea during pregnancy and congenital heart defects: a population-based case-control study.

The authors investigated the possible association between a mother's nausea during pregnancy and her child's risk for a congenital heart defect using data from the population-based Atlanta Birth Defects Case-Control Study conducted in 1982-1983. Case infants (n = 998) had nonsyndromic congenital heart defects and control infants (n = 3,029) had no congenital defects. Nausea during pregnancy (NP) was graded in eight levels of "severity" based on its onset, frequency, and duration. Level 1, the most severe NP, was associated with a lower risk for a congenital heart defect in the child (odds ratio (OR) = 0.81, 95% confidence interval (CI) 0.67-0.99) compared with no nausea. The lower risk tended to disappear with less severe levels of nausea, and the trend was statistically significant. Overall, early NP (levels 1 to 4 combined) with use of antinausea medication, particularly Bendectin (doxylamine, dicyclomine (dropped from the formulation in 1976), pyridoxine (vitamin B6)), was associated with a lower risk for congenital heart defects compared with: 1) absence of nausea (OR = 0.67, 95% CI 0.50-0.92), and 2) nausea without medication use (OR = 0.70, 95% CI 0.50-0.94). The results suggest that pregnancy hormones and factors or, alternatively, a component of Bendectin (most probably pyridoxine) may be important for normal heart development. These findings outline potential areas for future research on and prevention of congenital heart defects.

Adolescent↗

Polygenic expression of somatostatin in rainbow trout, Oncorhynchus mykiss: evidence of a preprosomatostatin encoding somatostatin-14.

Previously we reported the existence of two distinct cDNAs in rainbow trout that encode for separate preprosomatostatins (PPSS), each containing [Tyr7, Gly10]-somatostatin-14. In the present study, we used rainbow trout to further characterize the polygenic origin of somatostatins (SSs), a peptide hormone important in the regulation of growth, development, and metabolism of vertebrates. A two-phase rapid amplification of cDNA ends (RACE)-PCR was used for the isolation of selected cDNAs. We amplified and sequenced a ca. 350-bp 3' RACE-PCR fragment. Based upon this sequence we designed a second gene-specific primer for 5' RACE-PCR which yielded a 452-bp fragment. Sequence analysis revealed a 745-bp cDNA containing the complete 5'-untranslated region, a single initiation site 118 bases from the most 5' end, and a single putative polyadenylation site 17 bases from the most 3' end that was terminated with a polyadenylated tail. The deduced protein is a 114-amino acid PPSS molecule that contains a number of putative processing sites, potentially yielding a 26-amino acid peptide that could be processed further to a 14-amino acid peptide identical in structure to mammalian SS-14. Northern analysis revealed that PPSS-I was expressed in the pancreas, stomach, intestine, and brain of rainbow trout. These results suggest a polygenic origin of SS, possibly resulting from gene duplication events prior to the divergence of teleosts.

Amino Acid Sequence↗

Rainbow trout (Oncorhynchus mykiss) possess two somatostatin mRNAs that are differentially expressed.

Previously, we isolated a 624-bp cDNA encoding for a 115-amino acid preprosomatostatin containing [Tyr7,Gly10]-somatostatin (SS)-14 (now designated PPSS-II') obtained from the endocrine pancreas (Brockmann bodies) of rainbow trout. In this study we have characterized a second cDNA obtained from trout pancreas that is 600-bp in length and encodes for a 111-amino acid precursor containing [Tyr7,Gly10]-SS-14 (PPSS-II''). The nucleotide and amino acid identity between the two cDNAs is 82.3 and 80.5%, respectively. Both PPSS-II' and PPSS-II'' mRNA were present in esophagus, pyloric ceca, stomach, upper and lower intestine, and pancreas, whereas only SS-II" mRNA was present in brain. PPSS-II'' mRNA was more abundant than PPSS-II' mRNA in pancreas, whereas PPSS-II' mRNA was more abundant than PPSS-II" mRNA in stomach. Fasting increased pancreatic PPSS-II'' mRNA levels but had no effect on the levels of PPSS-II' mRNA. These results indicate the existence of two nonallelic pancreatic SS-II genes that are differentially expressed, both in terms of distribution among tissues and in terms of relative abundance within the tissues.

Amino Acid Sequence↗

The return of thalidomide: can birth defects be prevented?

Thalidomide, the drug that caused a worldwide epidemic of serious birth defects in the late 1950s and early 1960s, was recently approved by the US Food and Drug Administration (FDA) for use in treating the skin disease erythema nodosum leprosum, a complication of leprosy. The drug has also shown promise in the treatment of other serious diseases. If thalidomide is eventually approved for use in the US and other countries for treatment of diseases more prevalent than erythema nodosum leprosum, or if use of the drug for non-approved indications becomes widespread, hundreds of thousands of women with childbearing ability could be treated. If this should happen, can we prevent another epidemic of birth defects? In an effort to prevent fetal exposures to thalidomide, the FDA mandated a comprehensive programme to regulate prescription, dispensing and use of the drug. The programme is designed to require registration of all participating prescribers, pharmacies and patients. It also requires use of effective methods of contraception and periodic pregnancy testing of all patients with childbearing ability during treatment. Prescribers are directed to counsel both female and male patients on the risks, benefits and proper use of the drug, as well as on the proper use of contraceptives during treatment. The patient is required to sign an informed consent form before beginning treatment. Prescription and dispensing of thalidomide will be tightly controlled. Athalidomide registry will monitor prescription. dispensing and use of the drug, and will investigate all reported fetal exposures. This mandatory, but untested, programme promises to be effective at preventing fetal exposures to thalidomide, provided that patients, prescribers and pharmacists comply with all of its provisions. However, even if the programme proves to be successful in the US, there is concern that thalidomide may eventually be widely used in countries that may not require such stringent controls. In Brazil, where thalidomide is commercially available for treatment of leprosy patients, 33 cases of thalidomide embryopathy have already been reported in the literature. Even in countries that may tightly regulate the distribution and use of thalidomide, some patients may obtain the drug through black market sources. Should these events occur, many cases of thalidomide-induced birth defects could appear. Therefore, there is a need to develop nonteratogenic analogues of thalidomide that can provide effective treatment for erythema nodosum leprosum and other serious conditions without increasing the potential for another epidemic of thalidomide-related birth defects.

Adult↗

Mitochondrial DNA rearrangements, including partial duplications, occur in young and old rat tissues.

Using polymerase chain reaction (PCR) with back-to-back primers, 85 different mitochondrial DNA (mtDNA) rearrangements, consisting of partial duplications or mini-circles, were detected in brain, liver, and heart tissue from Fischer 344 rats. The regions around the mitochondrial tRNALeu(UUR) gene, the cluster of three tRNA genes [His, Ser(AGY), Leu(UUC)], as well as the region of the displacement loop were analyzed separately with different primer sets. Rearrangements were detected in all regions analyzed in samples taken throughout the animal life span, ranging from 1 day old to 33 months of age (senescent). Two-thirds of the rearrangements terminated at short (3-9-bp) direct repeats. Three of the different rearrangements were detected in more than one animal; the most common rearrangement was found in nine different template preparations. Two loci (hot spots) were found to be particularly susceptible to rearrangement, and both were located at sequences that exhibited highly conserved potential for secondary structure formation. The displacement loop region of 10 samples exhibited the presence of multiple tandem duplications ranging between 324 and 449 bp in length. One of these consisted of heterologous, but overlapping, repeating units. Identical PCR protocols were carried out in control experiments using a cloned fragment of mtDNA that encompassed the most common hot spot sequence. The results showed that this fragment did not artifactually generate a rearrangement junction under our PCR conditions and suggested that this sequence does not promote rearrangement mutations in bacteria during the cloning process.

Aging↗

Increased frequency of cystic fibrosis among infants with jejunoileal atresia.

There appears to be an increased frequency of cystic fibrosis (CF) among infants with jejunoileal atresia (JIA). However, the figures vary widely, and no population-based data exist. The purpose of this study was to quantitate the magnitude of the association between JIA and CF in Atlanta using population-based data from 1968 to 1995. Case subjects included all infants with isolated JIA born during 1968-1995 to mothers residing in the five-county metropolitan Atlanta area at the time of birth. To ascertain cases, we reviewed records of the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based birth defects registry. Caucasian JIA cases were cross-referenced with patients in the CF registry at the Egleston Cystic Fibrosis Center at Emory University to more completely ascertain the diagnosis of CF among JIA cases. During 1968-1995, MACDP ascertained a total of 94 isolated JIA cases, for a birth prevalence of 1.8/10,000 live births. Among the cases, 38 were Caucasian, 52 were African-American, and 4 were of Asian or Hispanic ethnicity. Four of the 38 Caucasian JIA cases (11%) also had CF. The expected number of JIA cases with CF is 0.019 based on the estimated population incidence of 1/ 2,000 for CF. The observed to expected (O/E) ratio of Caucasian JIA cases with CF is greater than 210 (P<0.0001). Caucasian infants with JIA have more than 210 times the risk for CF compared with Caucasian infants in the general population. The results of this study have implications for the management of infants born with JIA and genetic counseling for families with affected infants.

Academic Medical Centers↗

A data dependent computer algorithm for the detection of muscle activity onset and offset from EMG recordings.

This paper describes modifications to an algorithm presented by Marple-Horvat and Gilbey (1992) for identifying bursts of muscle activity in electromyographical (EMG) recordings. Our efforts to apply their algorithm to spontaneously moving infants and toddlers resulted in limited success. The modified algorithm makes several parameters dependent on the data being analyzed; these changes enabled it to analyze a variety of EMG recordings more effectively. The original algorithm had a success rate (correctly identified bursts) of 62.9% and combined error rate (number of insertions and deletions) of 73.0% when applied to an independent test data set. The modified algorithm displayed a success rate of 85.4% and combined error rate of 23.6%.

Adult↗

Amniotic band facies.

Craniofacial deformities of 14 patients with amniotic band syndrome at one institution were reviewed for morphologic similarities. In addition to associated cleft lip and palate, vertical and oblique facial clefts, which were not associated with embryologic lines of fusion, were seen. It is hypothesized that the prominence of the nasal processes combined with the adjacent stomodeal orifice results in utero surfaces, which can lead to free band attachment and adherence, resulting in a spectrum of similarly oriented facial defects.

Amniotic Band Syndrome↗

Dislocation of the mandible during the course of cataract surgery.

Spontaneous dislocation of the mandible is a well-described clinical entity with which the ophthalmologist may not be familiar. However, the widespread use of intravenous sedation places susceptible individuals at risk for the development of dislocation of the mandible. The authors describe a patient who underwent routine cataract surgery and suffered a dislocation of the mandible that initially went unrecognized. Ophthalmic surgeons who use intravenous sedation need to be aware of this complication and need to recognize the symptoms so that patients may receive timely attention.

Aged↗

Elevated rates of severe neural tube defects in a high-prevalence area in northern China.

In the northern provinces of China, the birth prevalence rate of neural tube defects (NTDs) is among the highest in the world-at about 6 per 1,000 births in rural areas. A unique population-based birth defects surveillance system in which photographs are taken of infants with selected external birth defects was implemented in two provinces in northern China and two provinces in southern China where NTD rates approximate those in the United States. In the period from March 1992 through December 1993, 660 infants with NTDs were identified by the surveillance project from a birth cohort of 251,567. We compared data from the two surveillance areas in China with data from a low-prevalence area in the United States to determine if the pattern of NTD types differs. Based on birth prevalence rates of NTDs from the Metropolitan Atlanta Congenital Defects Program, the observed to expected ratios for two types of NTDs are markedly increased at 80.8 for craniorachischisis and 25.0 for iniencephaly. Rates of these two NTDs in the southern provinces are increased to a lesser degree with observed to expected ratios of 7.1 for craniorachischisis and 2.7 for iniencephaly. The pattern of NTDs in northern China shows an increase in types that are rare in low-prevalence areas such as metropolitan Atlanta. Increased awareness of varying patterns of NTDs in different populations may have important implications for identifying etiologic and pathogenetic mechanisms of NTDs.

China↗

Population study of congenital hypothyroidism and associated birth defects, Atlanta, 1979-1992.

Very little data are available from population-based studies on congenital hypothyroidism (CH) epidemiology and patterns of associated birth defects. By linking data from two population-based registries, we describe the epidemiology of CH and associated defects in Atlanta from 1979-1992. Cases included all infants with CH born from 1979-1992 to mothers residing in the metropolitan Atlanta area at the time of birth. We ascertained CH cases by reviewing newborn screening records and records of the Metropolitan Atlanta Congenital Defects Program (MACDP), a population-based registry of all serious birth defects diagnosed during a child's first year of life. We linked CH cases with MACDP records to ascertain the presence of serious birth defects among infants with CH. Of 97 infants identified with CH through newborn screening and/or MACDP (1:5,000 live births), 87 had primary CH and 10 had secondary. The rate of primary CH was higher among non-hispanic whites than among blacks (1:4,400 vs. 1:10,000) and among females compared with males (1:4,000 vs. 1:7,700). Among infants with primary CH, 77 had isolated CH, 3 had Down syndrome, and 7 had unrelated major structural defects. Based on Atlanta population rates of Down syndrome and major structural anomalies, we infer i) infants with Down syndrome have a 35-fold increased risk for primary CH compared with infants in the general population (P < .0001); ii) infants with primary CH have a 2.2-fold increased risk for major structural anomalies (P < .05). Because this is the first population study of CH in the United States in which data from two population-based registries were linked, the epidemiologic patterns and associated defects are more representative than those found in studies based on newborn screening records only.

Adult↗

The spectrum of congenital anomalies of the VATER association: an international study.

The spectrum of the VATER association has been debated ever since its description more than two decades ago. To assess the spectrum of congenital anomalies associated with VATER while minimizing the distortions due to small samples and referral patterns typical of clinical series, we studied infants with VATER association reported to the combined registry of infants with multiple congenital anomalies from 17 birth defects registries worldwide that are part of the International Clearinghouse for Birth Defects Monitoring Systems (ICB-DMS). Among approximately 10 million infants born from 1983 through 1991, the ICB-DMS registered 2,295 infants with 3 or more of 25 unrelated major congenital anomalies of unknown cause. Of these infants, 286 had the VATER association, defined as at least three of the five VATER anomalies (vertebral defects, anal atresia, esophageal atresia, renal defects, and radial-ray limb deficiency), when we expected 219 (P<0.001). Of these 286 infants, 51 had at least four VATER anomalies, and 8 had all five anomalies. We found that preaxial but not other limb anomalies were significantly associated with any combination of the four nonlimb VATER anomalies (P<0.001). Of the 286 infants with VATER association, 214 (74.8%) had additional defects. Genital defects, cardiovascular anomalies, and small intestinal atresias were positively associated with VATER association (P<0.001). Infants with VATER association that included both renal anomalies and anorectal atresia were significantly more likely to have genital defects. Finally, a subset of infants with VATER association also had defects described in other associations, including diaphragmatic defects, oral clefts, bladder exstrophy, omphalocele, and neural tube defects. These results offer evidence for the specificity of the VATER association, suggest the existence of distinct subsets within the association, and raise the question of a common pathway for patterns of VATER and other types of defects in at least a subset of infants with multiple congenital anomalies.

Abnormalities, Multiple↗

Macrocephaly-cutis marmorata telangiectatica congenita: a distinct disorder with developmental delay and connective tissue abnormalities.

We describe 13 unrelated children with abnormalities of somatic growth, face, brain, and connective tissue including vasculature. Although the condition in these children falls under the general group of disorders known as cutis marmorata telangiectatica congenita (CMTC), the constellation of abnormalities appears to constitute a distinct and easily recognizable phenotype within this general group. In contrast to most children reported with CMTC, children in this subgroup have a high risk for neurologic abnormalities, including developmental delay, mental retardation, megalencephaly, and hydrocephalus. Early recognition of this condition is important for appropriate surveillance for known complications and parental counseling.

Abnormalities, Multiple↗