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J D Erickson

Publications and source records attributed to J D Erickson.

At least 19 recordsLinked to original sources
PubMed1992

Improved ascertainment of cardiovascular malformations in infants with Down's syndrome, Atlanta, 1968 through 1989. Implications for the interpretation of increasing rates of cardiovascular malformations in surveillance systems.

Several birth defects surveillance systems have shown an upward trend in the birth prevalence of several congenital cardiovascular malformations. Improvements in clinical ascertainment have been suggested as an explanation for this increase. For several decades, 40-50% of infants with Down's syndrome have been reported to have cardiac defects associated with the unbalanced genotype. Therefore, secular changes in the frequency of ascertained cardiovascular malformations among infants with Down's syndrome in surveillance systems could shed light on improvements in the ascertainment of these defects. The authors examined changes in the frequency of ascertained cardiovascular malformations among 532 cases of Down's syndrome recorded in the Metropolitan Atlanta Congenital Defects Program from 1968 through 1989. Overall, 33% of the cases have reported cardiovascular malformations. However, the frequency of these defects in Down's syndrome infants increased dramatically from about 20% in the early 1970s to more than 50% in the late 1980s (p = 0.0001). This upward trend was seen for all major categories of cardiac defects and persisted after the cases were stratified by race, sex, maternal age, hospital of birth, birth weight, and gestational age. These results show improvement in the ascertainment of cardiovascular malformations among Down's syndrome infants in a surveillance population. They are also consistent with the hypothesis that the increasing rates of cardiac defects are related, at least in part, to improved ascertainment of these defects in the population.

Down Syndrome↗
PubMed1992

Expression cloning of a reserpine-sensitive vesicular monoamine transporter.

A cDNA for a rat vesicular monoamine transporter, designated MAT, was isolated by expression cloning in a mammalian cell line (CV-1). The cDNA sequence predicts a protein of 515 amino acids with 12 putative membrane-spanning domains. The characteristics of [3H]serotonin accumulation by CV-1 cells expressing the cDNA clone suggested sequestration by an intracellular compartment. In cells permeabilized with digitonin, uptake was ATP dependent with an apparent Km of 1.3 microM. Uptake was abolished by the proton-translocating ionophore carbonylcyanide p-trifluoromethoxyphenylhydrazone and with tri-(n-butyl)tin, an inhibitor of the vacuolar H(+)-ATPase. The rank order of potency to inhibit uptake was reserpine > tetrabenazine > serotonin > dopamine > norepinephrine > epinephrine. Direct comparison of [3H]monoamine uptake indicated that serotonin was the preferred substrate. Photolabeling of membranes prepared from CV-1 cells expressing MAT with 7-azido-8-[125I]iodoketanserin revealed a predominant tetrabenazine-sensitive photolabeled glycoprotein with an apparent molecular mass of approximately 75 kDa. The mRNA that encodes MAT was present specifically in monoamine-containing cells of the locus coeruleus, substantia nigra, and raphe nucleus of rat brain, each of which expresses a unique plasma membrane reuptake transporter. The MAT cDNA clone defines a vesicular monoamine transporter representing a distinct class of neurotransmitter transport molecules.

Affinity Labels↗
PubMed1992

Can maternal risk factors influence the presence of major birth defects in infants with Down syndrome?

Although the manifestations of Down syndrome (DS) are well known, certain major birth defects such as duodenal atresia and endocardial cushion defects are present in some infants but not others, suggesting the possible role of other genetic or environmental factors interacting with the trisomy genotype. To explore the possible role of maternal factors in the presence of major defects among DS infants, we examined data from an epidemiologic study of DS conducted in metropolitan Atlanta. Of 219 DS infants born between 1968 and 1980, 50 had recorded cardiac defects, 9 had selected gastrointestinal atresias and 4 had oral clefts. We evaluated the association of these defects with several maternal factors including age, race, first trimester cigarette smoking, alcohol use, and fever. We found that different maternal factors were associated with several defects: (1) mother's race with cardiac defects (40% in blacks vs. 17% in whites, P less than 0.01), (2) mother's age with oral clefts (6% for less than 25 years, 1% for 25-34, and 0% for greater than 34, P less than 0.05), and (3) maternal first trimester fever with gastrointestinal defects (15% in infants with history of fever and 3% in infants without a history of fever, P less than 0.01). We also observed an inverse relationship between maternal alcohol use and the presence of ventricular septal defect. These findings suggest that maternal risk factors may influence the clinical manifestations of DS. In addition to searching for a genetic basis for the DS phenotype, we suggest that the role of environmental factors and maternal exposures be specifically explored in clarifying the genesis of various birth defects in Down syndrome.

Alcohol Drinking↗
PubMed1992

Birth prevalence study of the Apert syndrome.

Estimates of the Apert syndrome birth prevalence and the mutation rate are reported for Washington State, Nebraska, Denmark, Italy, Spain, Atlanta, and Northern California. Data were pooled to increase the number of Apert births (n = 57) and produce a more stable birth prevalence estimate. Birth prevalence of the Apert syndrome was calculated to be approximately 15.5/1,000,000 births, which is twice the rate determined in earlier studies. The major reason appears to be incomplete ascertainment in the earlier studies. The similarity of the point estimates and the narrow bounds of the confidence limits in the present study suggest that the birth prevalence of the Apert syndrome over different populations is fairly uniform. The mutation rate was calculated to be 7.8 x 10(-6) per gene per generation. Apert syndrome accounts for about 4.5% of all cases of craniosynostosis. The mortality rate appears to be increased compared to that experienced in the general population; however, further study of the problem is necessary.

Acrocephalosyndactylia↗
PubMed1992

The changing epidemiology of neural tube defects. United States, 1968-1989.

OBJECTIVE: To describe the recent trends and epidemiologic characteristics of neural tube defects in the United States. RESEARCH DESIGN: Ongoing surveillance data. SETTING: Two birth defect surveillance systems: the nationwide Birth Defects Monitoring Program and the Metropolitan Atlanta (Ga) Congenital Defects Program for 1970 through 1989 and 1968 through 1989, respectively. PARTICIPANTS: Between 1970 and 1989, using discharge diagnoses of approximately 1 million live-born and stillborn infants per year, the Birth Defects Monitoring Program identified 15,503 cases of spina bifida and anencephaly. Between 1968 and 1989, using discharge diagnoses and clinical records until age 1 year of 38,000 infants per year, the Metropolitan Atlanta Congenital Defects Program identified 800 cases of spina bifida and anencephaly. INTERVENTIONS: None. MEASUREMENTS/MAIN RESULTS: Nationwide, neural tube defect rates have declined from 1.3 per 1000 births in 1970 to 0.6 per 1000 births in 1989. In Atlanta, neural tube defect rates have declined from 2.0 per 1000 births in 1968 to 0.6 per 1000 births in 1989. Several changes in the epidemiologic characteristics of neural tube defects were observed: (1) the proportion of spina bifida cases has increased; (2) the proportion of neural tube defect cases compared with the proportion of other unrelated defects has increased; (3) the race ratio of whites to other races for isolated neural tube defect cases has declined in Atlanta; and (4) the rate of isolated neural tube defects in females has also decreased. CONCLUSIONS: The declining rates of neural tube defects can be partially explained by increased widespread prenatal diagnostic techniques, strongly suggesting the role of environmental factors in neural tube defects. In particular, the use of multivitamins and folic acid to prevent the occurrence of neural tube defects needs further evaluation. Nevertheless, the changing clinical and epidemiologic characteristics of cases over time points to the etiologic heterogeneity of these conditions.

Anencephaly↗
PubMed1992

Interpretation of recurring weak associations obtained from epidemiologic studies of suspected human teratogens.

Epidemiological studies of suspected human teratogens not infrequently lead to recurring weak or moderate associations (relative risks or odds ratios ranging from greater than 1 to 3 for adverse effects and from 1/3 to less than 1 for protective effects) between specific defects and prenatal exposures. Examples of such associations include cigarette smoking and oral clefts (odds ratios between 1 and 2) and periconceptional multivitamin/folic acid supplementation and neural tube defects (odds ratios from 1/3 to 1). In this paper, we illustrate that low relative risk recurring in well-designed studies may reflect underlying biologic mechanisms and should not be readily dismissed. Low relative risks could be the result of a combination of the following factors: 1) unmeasured confounding, 2) exposure misclassification (often related to the inability to pinpoint relevant dose and timing), 3) outcome misclassification (related to the etiologic heterogeneity of birth defects), 4) biologic interactions (related to teratogenic effects in population subgroups defined by genetic susceptibility or the presence of other exposures), and 5) differential prenatal survival (related to the combined impact of the exposure and the defect on prenatal survival). These issues can be addressed in epidemiologic studies by using biological markers of exposure and susceptibility, dysmorphologic evaluation of affected infants, subgroup analysis for etiologic heterogeneity, a search for biologic interactions, and the use of prospective cohort studies. Finally, low relative risks in the face of common exposures can reflect an important public health contribution of the exposure to the occurrence of the defect in the population.

Abnormalities, Drug-Induced↗
PubMed1992

Sites of synthesis of chromogranins A and B in the human brain.

The sites of synthesis of the chromogranins A and B, and their potential processed peptides, were examined by quantitating the levels of chromogranin A and B mRNA in various regions of the human brain by Northern blot analysis. Chromogranin A and B mRNA expression in the brain is region-specific and confined to grey matter. In situ hybridization histochemistry detected chromogranin A and B mRNA in pyramidal neurons of human cerebral cortex. Cell-specific expression in subpopulations of cerebrocortical neurons suggest that chromogranin A and B gene products may play a role in central neuronal function.

Brain↗
PubMed1991

Regional distribution and partial molecular characterization of CD4-related mRNA in human brain and peripheral tissues.

We purified human poly(A)+ RNA from 11 individuals to assess the regional distribution of CD4 and CD4-related mRNA transcripts in human brain and in peripheral tissues by Northern blot hybridization. A 3.0 kb CD4 mRNA transcript was expressed in all brain areas and several peripheral tissues examined. A second CD4-related 1.8 kb mRNA species showed an uneven distribution in the brain with cortical regions possessing highest levels and basal ganglia, thalamus, cerebellum and spinal cord containing relatively lower amounts. Messenger RNA transcripts for CD8, a T cell specific marker, were not detectable in human brain by Northern analysis, yet were as abundant as CD4 in spleen. The expression of the 1.8 kb mRNA was tissue specific as it was not observed in peripheral tissues such as spleen, adrenal, colon, or lung, nor was it found in the choroid plexus, dorsal root ganglion and human neuronal (SY5Y) or astroglial (N132N1) cell lines. Blot hybridization and S1 nuclease protection analysis of poly(A)+ RNA with selective probes derived from CD4 indicated that the 1.8 kb mRNA transcript is truncated, lacking the extracellular protein coding region of CD4, and may in fact be a unique transcript from the CD4 gene locus rather than an alternatively spliced or processed CD4 mRNA.

Adult↗
PubMed1990

Chloride ion increases [3H]dopamine accumulation by synaptic vesicles purified from rat striatum: inhibition by thiocyanate ion.

The effect of chloride ion on the transport of [3H]dopamine into synaptic vesicles purified from rat striatum has been evaluated. The inclusion of 10 mM chloride ion in the incubation medium produced a 100% increase in temperature-sensitive [3H]dopamine uptake into synaptic vesicles from approximately 1800 pmol/mg to 3600 pmol/mg of protein. Half-maximal effects were observed with chloride ion at 4 mM concentration. The anion selectivity of stimulation supports the presence of anion channels within the membranes of dopaminergic storage organelles. Low concentrations of thiocyanate ion (less than 10 mM), 4-acetamido-4'-isothiocyano-2-2'-disulfonic acid stilbene (100 microM), and duramycin (5 micrograms/ml) selectively blocked the chloride ion stimulated accumulation of [3H]dopamine. Higher concentrations of these agents are required to significantly reduce [3H]dopamine uptake in the absence of chloride ion. These results suggest that both components of the proton electrochemical gradient (delta psi and delta pH) are important for dopamine uptake by brain vesicles. This article presents the first demonstration that chloride ion plays a role in the transport of dopamine into vesicles isolated from the CNS.

Animals↗
PubMed1979

Paternal age and Down syndrome.

The frequency of Down syndrome (DS) in infants of older fathers has been examined in two sets of data. The effect of maternal age was controlled by single years of age. Lack of tight control has been an important weakness of other studies on this subject. Data obtained in metropolitan Atlanta by an intensive case-ascertainment program showed no overall excess of DS infants born to older fathers. Nor was there evidence of such an effect in recent birth certificate data made available by the National Center for Health Statistics. The Atlanta data suggest an increased number of DS infants born to older fathers who had children by women less than or equal to 34 years. However, there was a small deficiency of DS infants born to older fathers by women greater than or equal to 35 years. The possibility of a paternal-age effect remains open, but the available data suggest that, if it exists, it is quite small.

Adult↗
PubMed1978

Mortality in selected cities with fluoridated and non-fluoridated water supplies.

Mortality rates (for blacks and whites only) in 24 cities with fluoridated and 22 with non-fluoridated water supplies in the United States were compared for the years 1969-1971. During these three years 570,671 deaths occurred in the cities with fluoridated water; the 1970 reference population in those cities was 15,972,817. The figures for the cities with non-fluoridated water were 351,053 and 11,106,746 respectively, so that the crude death rates for all causes were 1190.9 (fluoridated) and 1053.6 (non-fluoridated) per 100,000 person-years. Adjustments for age, sex and race reduced differences for some causes and removed them for others. Further correction, using analyses of covariance for city characteristics that influence mortality, gave adjusted death rates for all causes of 1123.9 and 1137.1, and for malignant neoplasms 195.3 and 196.9, in the cities with fluoridated and non-fluoridated water respectively. I found no evidence of a harmful effect of fluoridation.

Age Factors↗
PubMed1978

Patent ductus arteriosus and ventricular septal defect: trends in reported frequency.

Nationwide secular increases in the reported frequency of patent ductus arteriosus (PDA) and ventricular septal defect (VSD) are presented. Detailed examination of data from one locality, Metropolitan Atlanta, indicates that the increases were primarily the result of a rise in the reported frequency of these heart defects in isolated form (i.e., without other malformations). During the latter years of the study more Atlanta babies with isolated PDA were of low birth weight and short gestational age, and more cases were diagnosed in the infants' first week of life. The increase in VSD was not as consistent nor as dramatic as that of PDA. Neither were there any changes over time in the demographic characteristics of Atlanta infants affected by isolated VSD. At least part and perhaps all of the increase in PDA may be explained by an increased awareness on the part of physicians who take care of premature infants. While the increase in reported VSD may be explainable on the basis of awareness or secular shifts in diagnostic standards, the problem seems qualitatively different from that of PDA.

Black or African American↗
PubMed1978

Down syndrome, paternal age, maternal age and birth order.

Recent cytogenetic evidence has shown that trisomy 21 can arise, perphaps even in substantial proportion, from paternal nondisjunction. The statistical association between Down syndrome incidence and maternal age, paternal age and birth order has been studied in a sample of over 4000 cases. The size of this sample made it possible to control for the effect of maternal age by single years of age during the search for a paternal age effect and vice versa, and the importance of such stringent control is emphasized. The maternal age association was confirmed with an extremely high degree of statistical significance while no independent effect of paternal age was found; indeed, the rates at paternal ages over 45 years appear to be nearly constant. After adjusting for the effects of parental age, a significant inverse association of birth order with incidence was noted. It also appears that the incidence among very young mothers may be high: for maternal ages 15 years and less the rates seem to be equivalent to those found at 30 or 35 years. In order to help answer the question of whether the maternal age association is the result of increasing rates of nondisjunction or of some other mechanism (for example, an age related defect in a spontaneous abortion screening mechanism), the proportion of cases due to maternal and paternal nondisjunction at different parental ages must be determined.

Adolescent↗
PubMed1978

Interpregnancy interval. Association with birth weight, stillbirth, and neonatal death.

Pairs of first and second births and pairs of second and third births to the same Norwegian mothers were studied to determine the association between interpregnancy interval and birth weight, stillbirth, and neonatal death. Use of the pair approach provides one birth which could possibly have been affected by the length of the interval and one birth which could not. The association of interval and birth weight for births which precede an interval is found to be equivalent to that for births which follow an interval. The data on stillbirth are compatible with higher rates at long intervals while the data on neonatal death are consistent with higher rates at short intervals. However, we conclude that manipulation of the interval between pregnancies is unlikely to have any marked, direct, beneficial effect on outcome of pregnancy.

Birth Order↗