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Biomedical subjects

J F Cordero

Publications and source records attributed to J F Cordero.

At least 19 recordsLinked to original sources
PubMed2002

Caffeine activates a mechanosensitive Ca(2+) channel in human red cells.

Caffeine is known to activate influx of both mono- and divalent cations in various cell types, suggesting that this xanthine opens non-selective cation channels at the plasma membrane. This possibility was investigated in human erythrocytes, studying the caffeine action on net Ca(2+), Na(+) and K(+) movements in ATP-depleted cells. Whole populations and subpopulations of young and old erythrocytes were employed. Caffeine was tested in the presence of known mechanosensitive channel blockers (Gd(3+), neomycin and amiloride) and ruthenium red as a possible inhibitor. Caffeine enhanced net cation fluxes in a concentration-dependent way. In whole populations, the Ca(2+) entry elicited by 20 mM caffeine was fully suppressed by Gd(3+) (5 microM), amiloride (250 microM) and ruthenium red (100 microM) and partially blocked by neomycin (100 microM). The above blockers also inhibited caffeine-dependent Na(+) entry whilst showing antagonistic effects on the corresponding K(+) efflux. These compounds fully suppressed hypotonically-induced (-35 mOsm/kg) Ca(2+) influx at nearly the same concentrations completely blocking caffeine-stimulated Ca(2+) entry. The effect of inhibitors on Ca(2+) influx in young cells exceeded that in old cells at similar concentrations. The results clearly show that caffeine stimulates a stretch-activated Ca(2+) channel in human red cells and that aged cells are less susceptible to mechanosensitive channel blockers.

Adenosine Triphosphate↗
PubMed2001

Varicella vaccine exposure during pregnancy: data from the first 5 years of the pregnancy registry.

OBJECTIVE: To assess the risks of congenital varicella syndrome and other birth defects in offspring of women who inadvertently received varicella vaccine during pregnancy or within 3 months of conception. METHODS: Pregnant women inadvertently exposed to varicella vaccine, reported voluntarily, were enrolled in the Pregnancy Registry for VARIVAX (Merck & Co., Inc., West Point, PA). The pregnancies were monitored and the outcomes ascertained from questionnaires completed voluntarily by the health care providers. The rates of congenital varicella syndrome and congenital anomalies were calculated for seronegative women prospectively reported to the registry. RESULTS: From March 17, 1995 through March 16, 2000, 362 pregnancy outcomes were identified from prospective reports. Ninety-two women were known to be seronegative to varicella, of whom 58 received their first dose of vaccine during the first or second trimester. No cases of congenital varicella syndrome were identified among 56 live births (rate 0%, 95% confidence interval [CI] 0, 15.6). Among all the prospective reports of live births, five congenital anomalies were reported. No specific pattern was identified in either the susceptible cohort or the sample population as a whole. CONCLUSION: No abnormal features have been reported that suggested the occurrence of congenital varicella syndrome or other birth defects related to vaccine exposure during pregnancy. Because of the small numbers, this study has limited precision, so continued surveillance is warranted. However, these results should provide some assurance to health care providers and women with inadvertent exposure before or during pregnancy.

Adolescent↗
PubMed2000

National, state, and urban area vaccination coverage levels among children aged 19-35 months--United States, 1998.

PROBLEM/CONDITION: High vaccination levels in the population are necessary to decrease disease transmission and prevent disease; therefore, an important component of the U.S. vaccination program is the assessment of vaccination coverage. Current goals are for > or = 90% coverage with recommended vaccines during the first 2 years of life. REPORTING PERIOD: January-December 1998. DESCRIPTION OF SYSTEMS: The National Immunization Survey (NIS) is an ongoing, random-digit-dialed telephone survey that gathers vaccination coverage data for children aged 19-35 months in all 50 states and 28 urban areas. Vaccination coverage rates derived from NIS data are adjusted statistically for households with multiple telephone lines, household nonresponse, the proportion of households without telephones, and vaccination provider nonresponse. The results were also adjusted to match the known total population of children in each survey area. RESULTS: On the basis of NIS data, national coverage was > or = 90% for three doses of poliovirus vaccine (Polio), three doses of Haemophilus influenzae type b vaccine (Hib), and one dose of measles-containing vaccine (MCV). Coverage was the highest ever reported for four doses of any diphtheria and tetanus toxoids and pertussis vaccine (DTP) (i.e., diphtheria and tetanus toxoids and pertussis vaccine, diphtheria and tetanus toxoids [DT], or diphtheria and tetanus toxoids and acellular pertussis vaccine [DTaP]) (83.9%), three doses of hepatitis B vaccine (Hep B, 87.0%), and one dose of varicella vaccine (43.2%). The number of states achieving the > or = 90% goal was 47 for three doses of Hib, 40 for three doses of Polio, 40 for one dose of MCV, nine for three doses of Hep B, and seven for four doses of DTP. Proportionally fewer urban areas achieved the > or = 90% goal: 23 of 28 for three doses of Hib, 13 for three doses of Polio, 16 for one dose of MCV, five for three doses of Hep B, and one for four doses of DTP. No state or urban area has yet achieved the > or = 90% goal for varicella. INTERPRETATION: Findings from the 1998 NIS indicate that national vaccination coverage levels for routinely recommended childhood vaccines are at the highest levels ever reported. However, substantial variation in coverage remains at the state and urban area levels. PUBLIC HEALTH ACTIONS: The public health community and vaccination providers in areas with low coverage should intensify their efforts to implement recommended strategies for increasing vaccination coverage to ensure that children are equally well protected throughout the United States.

Child, Preschool↗
PubMed2000

Preparing for elimination of congenital Rubella syndrome (CRS): summary of a workshop on CRS elimination in the United States.

The goal of eliminating indigenous rubella and congenital rubella syndrome (CRS) in the United States in the near future is now within reach, because rubella incidence has been sustained at record-low levels since the mid-1990s. Effective prevention strategies to eliminate CRS and rubella require improvement in the surveillance of CRS and congenital rubella infection (CRI). The purpose of the workshop was to review rubella and CRS epidemiology, as well as current clinical, diagnostic, and laboratory practices, to determine whether new strategies are needed to achieve and document CRS elimination. Workshop participants agreed that surveillance for CRS must be strengthened, particularly through augmented laboratory capabilities, and the case definition for CRS must be revised to reflect the current scientific information available. Further studies of methods are needed to identify high-risk populations and geographic areas for rubella and CRS and to enhance identification of infants with CRS.

Humans↗
PubMed1997

Reported biomedical causes and associated medical conditions for mental retardation among 10-year-old children, metropolitan Atlanta, 1985 to 1987.

This report describes biomedical causes of mental retardation (MR) among school-age children and associated medical conditions in children for whom no cause was reported. This study involved 715, 10-year-old children with MR (intelligence quotient [IQ] 70 or less) born between 1975 and 1977. We determined biomedical causes of MR using a hierarchical approach based on the timing of the event (i.e. prenatal, perinatal, or postneonatal). Among children with no identified biomedical cause the occurrence of associated medical conditions was examined. No reported biomedical cause could be found in 78% of children with MR (87% mild, IQ 50 to 70; 57% severe, IQ < 50). Prenatal causes were present in 12%, perinatal causes in 6%, and postneonatal causes in 4%. On the basis of these findings it was concluded that intensive use of public health prevention strategies can reduce the number of children who receive a diagnosis of MR.

Child↗
PubMed1996

Descriptive epidemiology of holoprosencephaly and arhinencephaly in metropolitan Atlanta, 1968-1992.

We report the descriptive epidemiology of holoprosencephaly and arhinencephaly using data from the Metropolitan Atlanta Congenital Defects Program, a population-based birth defects surveillance system with multiple sources of ascertainment. From 1968-1992, we ascertained 63 cases of holoprosencephaly and arhinencephaly from approximately 734,000 births, for a birth prevalence of 0.86 per 10,000. Thirteen case infants with holoprosencephaly and four case infants with arhinencephaly were categorized as having syndromes. Of the case infants with non-syndromic holoprosencephaly, 55% had malformations not attributable to the underlying brain defect. The rate of holoprosencephaly and arhinencephaly increased from 0.58 per 10,000 during 1968-1972 to 1.2 per 10,000 during 1988-1992 (P for trend = 0.016). Rates were higher for females than for males (risk ratio = 1.45, 95% C.I. 0.88-2.41) and higher for nonwhites than for whites (risk ratio = 1.74, 95% C.I. 1.06-2.86). There was a U-shaped distribution of risk associated with maternal age with a slightly increased risk for younger women (risk ratio for maternal age < 20 years, compared with age 25-29 years = 1.68, 95% C.I. 0.77-3.62) and older women (risk ratio for maternal age > 34 years, compared with age 25-29 years = 2.30, 95% C.I. 0.93-5.7), but this was not statistically significant. The increased risk in the older age group could be largely explained by the presence of cases with autosomal trisomies. Neonatal mortality was higher for infants with malformations that were not attributable to the underlying brain defect and for infants with syndromes than for infants with isolated holoprosencephaly. This analysis is the first population-based study with long-term data on this rare defect. Further epidemiologic studies will be necessary to assess the risk factors for holo-prosencephaly and arhinencephaly.

Abnormalities, Multiple↗
PubMed1994

Prevention of folic acid-preventable spina bifida and anencephaly.

The results of the British Medical Research Council's randomized controlled trial proved that folic acid can prevent spina bifida and anencephaly. The trial provided critical scientific data upon which to base public health policy for preventing folic acid-preventable spina bifida and anencephaly. Within weeks of publication of the results, the Centers for Disease Control and Prevention in the US developed and issued guidelines for women who had had a pregnancy affected by spina bifida or anencephaly. A year later, the US Public Health Service issued the recommendation that all women of child-bearing age who are capable of becoming pregnant should consume 0.4 mg of folic acid per day. The Public Health Service needed a year to make inferential judgements about dose, target groups, safety, timing of ingestion, and existing and proposed vitamin and drug policies and regulations. Current policy discussions concern whether to permit manufacturers of vitamins or food products to claim that folic acid will prevent folic acid-preventable spina bifida and anencephaly and whether to allow a food staple to be fortified with folic acid.

Anencephaly↗
PubMed1993

The epidemiology of disasters and adverse reproductive outcomes: lessons learned.

A disaster has been defined as a disruption of human ecology that exceeds the capacity of the community to function normally. Little is known about the adverse effects of natural disasters on reproductive outcomes. Important lessons can be derived from several disasters caused by human factors, such as the Minamata Bay disaster. Adverse reproductive outcomes include infertility, early pregnancy loss, stillbirths, congenital malformations, and serious developmental disabilities such as cerebral palsy and mental retardation. Recent disasters like the Chernobyl and Bhopal explosions have provided important lessons on the need for accurate and sound information about the risk of prenatal exposures for adverse reproductive outcomes. To study questions of adverse reproductive outcomes and disasters requires a well-planned approach. It should include early development of surveillance for adverse reproductive outcomes, analytic studies on the risk of disasters from direct and indirect effects, sensitive methods to measure early pregnancy loss, and long-term follow-up programs to assess outcomes such as developmental disabilities.

Animals↗
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

Trends in rates of multiple vascular disruption defects, Atlanta, 1968-1989: is there evidence of a cocaine teratogenic epidemic?

Research suggests that, perhaps through mechanisms initiated by vasoconstriction and leading to vessel thrombosis or embolism, cocaine causes vascular disruption defects, and that frequent cocaine use during early pregnancy could disrupt multiple organ systems in the fetus. We hypothesized that if cocaine is an important cause of multiple vascular disruption defects, a rising prevalence of cocaine use by mothers during pregnancy should be accompanied by rising rates of these defects in their offspring. Using data from the Metropolitan Atlanta Congenital Defects Program, we identified all infants born in Atlanta from 1968 through 1989 who had nonsyndromic, provisional vascular disruption defects affecting more than one organ system: 61 infants (78%) had gastrointestinal and genitourinary defects, 7 (9%) had gastrointestinal and abdominal wall defects, 2 (3%) had gastrointestinal and limb reduction defects, 2 (3%) had limb reduction and abdominal wall defects, 2 (3%) had central nervous system and gastrointestinal defects, 2 (3%) had genitourinary and limb reduction defects, 1 (1%) had genitourinary and abdominal wall defects, and 1 (1%) had central nervous system and genitourinary defects. The prevalence of Atlanta infants with more than one vascular disruption defect is 0.13 per 1,000 live births. Chi-square analysis for trends showed no increase in prevalence during the study period. Our data are from one of the first population-based studies in which trends for defects potentially caused by maternal cocaine use are examined; the results of our study show no significant change in the prevalence of multiple vascular disruption defects over time.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗
PubMed1992

Maternal diabetes: the risk for specific birth defects.

We studied the risk for specific birth defects among infants of mothers with gestational and chronic diabetes using data collected by the Spanish Collaborative Study of Congenital Malformations (ECEMC). For the years 1976 to 1985, we identified 10,087 infants with malformations and 9,994 control infants; 155 of the case infants and 89 of the controls were born to diabetic mothers. The crude odds ratio for any minor or major defect and insulin-treated diabetes was 5.5 (95% CI = 1.2, 24.8), and for major malformations it was 8.7 (95% CI = 1.8, 34.7). The risk for defects involving the central nervous system (CNS), skeletal system and cardiovascular system were significantly increased. Infants of non-insulin-treated diabetic mothers were 2.9 times more likely to have a major congenital birth defect (95% CI = 1.2, 7.2). The crude odds ratio for any major or minor defect and mothers with gestational diabetes requiring insulin was 1.9 (95% CI = 1.1, 3.4). Similar risk was observed for major defects (OR = 1.9, 95% CI = 1.0, 3.7). These results suggest that infants of insulin-treated diabetic mothers have an increased risk of developing malformations of the CNS, cardiovascular system and skeletal system. We also found an increased risk for specific defect categories among infants of mothers with gestational diabetes treated with insulin.

Abnormalities, Multiple↗
PubMed1992

Registries of birth defects and genetic diseases.

Registries can be very useful scorecards for tracking the occurrence of birth defects and genetic diseases and for monitoring the effectiveness of prevention programs. They can also help us to identify causes and risk factors and develop new prevention approaches. For registries to be useful, however, their data must be precise and focus on time, place, person, and diagnosis.

Congenital Abnormalities↗
PubMed1992

Acyclovir in pregnancy registry: six years' experience. The Acyclovir in Pregnancy Registry Advisory Committee.

The Acyclovir in Pregnancy Registry was established to gather data on prenatal exposure to acyclovir. Exposed pregnancies are tracked prospectively to ascertain exposure, risk factors, and pregnancy outcome. Through June 30, 1990, 312 acyclovir-exposed pregnancies had been reported and followed. Of these, 239 were exposed during the first trimester; outcomes included 24 spontaneous fetal losses, 47 induced abortions, 159 live births of infants without congenital abnormalities, and nine outcomes with congenital abnormalities. Among the 73 second- and third-trimester exposures, one infant was born with an abnormality. Exposures are also reported to the registry retrospectively, ie, after the outcome of pregnancy is known. Registry findings to date do not show an increase in the number of birth defects among the prospective reports when compared with that expected in the general population, and there is no consistent pattern of abnormalities among retrospective or prospective reports. These findings should provide some reassurance in counseling women following inadvertent prenatal exposure. The cases accumulated to date represent a sample of insufficient size for reaching reliable and definitive conclusions about the safety of acyclovir for pregnant women and their developing fetuses. Therefore, until further information is available, the Acyclovir in Pregnancy Registry Advisory Committee recommends following the 1989 Centers for Disease Control Sexually Transmitted Diseases Treatment Guidelines for the use of acyclovir in pregnancy, and encourages reporting of all prenatal exposures to the registry (1-800-722-9292, ext. 8465).

Acyclovir↗