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Biomedical subjects

R Casey

Publications and source records attributed to R Casey.

At least 37 records · Page 2Linked to original sources
PubMed1996

Corneoscleral laceration caused by air-bag trauma.

PURPOSE: To report a case of a corneoscleral laceration sustained as a direct result of inflation of a driver-side air bag. METHODS: A patient who sustained a severe ocular injury in a low-speed motor vehicle accident underwent clinical and radiologic examination and subsequent treatment. RESULTS: The left eye underwent primary repair of a complex corneoscleral laceration. Two weeks postoperatively, visual acuity in the left eye remained at bare hand motion. CONCLUSION: Although air-bag-related eye trauma may be relatively infrequent, the severity of the injuries incurred warrant research efforts to explore new air-bag designs that minimize the risk of ocular injury.

Accidents, Traffic↗
PubMed1996

Inducible nitric oxide synthase gene expression in vascular cells after transient focal cerebral ischemia.

BACKGROUND AND PURPOSE: We investigated whether inducible nitric oxide synthase (iNOS) is expressed after transient cerebral ischemia and, if so, we sought to define the temporal profile and cellular localization of the expression and the role of iNOS in the mechanism of ischemic brain injury. METHODS: The middle cerebral artery in rats was occluded for 2 hours by an intraluminal filament. The occurrence of transient ischemia and reperfusion was confirmed by laser-Doppler flowmetry (n = 5). iNOS message in the ischemic neocortex was determined by reverse-transcription polymerase chain reaction. iNOS enzymatic activity was assessed by citrulline assay. The cellular localization of iNOS expression was determined by immunohistochemistry. RESULTS: iNOS mRNA was maximally expressed in postischemic brain at 12 hours and was not present at 4 days (n = 3 per time point). iNOS mRNA was not observed in the contralateral cerebral cortex. iNOS enzymatic activity developed in the postischemic brain between 12 and 24 hours (P < .05) and subsided at 4 days (n = 4 to 8 per time point). iNOS immunoreactivity in the ischemic region was restricted to the wall of capillaries and of larger blood vessels at 12 to 24 hours. In regions of early necrosis, inflammatory cells were iNOS positive. Treatment with the iNOS inhibitor aminoguanidine (n = 5; 100 mg/kg IP, BID for 4 days), starting 6 hours after ischemia, reduced infarct size in neocortex by 36 +/- 7% in comparison with vehicle-treated controls (n = 5) (P < .05). CONCLUSIONS: Transient focal ischemia leads to iNOS expression in postischemic brain. However, the spatial and temporal patterns of expression differ from those occurring in permanent ischemia: iNOS is induced earlier and predominantly in vascular cells rather than in neutrophils. Thus, the temporal profile and localization of postischemic iNOS expression depend on the nature of the ischemic insult. The finding that aminoguanidine reduces infarct size adds further support to the hypothesis that postischemic iNOS expression contributes to ischemic brain damage.

Animals↗
PubMed1996

Longitudinal assessment for lead poisoning.

In a previous study, we showed that in our region the prevalence of lead poisoning (Pb > or = 10 micrograms/dL [0.483 mumol/L]) was high (29%) among urban infants. The objectives of this study were to assess the prevalence of lead poisoning over time in this cohort to determine the best screening strategy. Eighty-nine percent (115/129) of infants who were initially screened for lead poisoning between 6 and 12 months of age had a repeat venous lead level by age 3 years (mean = 19.8 months). The majority (70%) lived in a major city and had private medical insurance (80%). The initial and repeat mean venous lead levels were similar for the overall population (lead1 = 8.7 micrograms/dL +/- 6.2 [0.420 +/- 0.299 mumol/L] and lead2 = 7.7 micrograms/dL +/- 6.8 [0.371 +/- 0.328 mumol/L]). However, the percentage of lead-poisoned (Pb > or = 10 micrograms/dL or 0.483 mumol/L) children whose levels were > or = 15 micrograms/dL (0.724 mumol/L) increased from 28% to 48% on repeat. The utility of the initial screen in predicting a second elevated lead level > or = 20 micrograms/dL (0.966 mumol/L) was as follows: sensitivity = 33%, specificity = 97%, positive predictive value = 40%, negative predictive value = 96%. We conclude that in this population, a single screen at 18-24 months of age would reduce the need for multiple venipunctures and would detect those children in need of an intervention.

Child, Preschool↗
PubMed1996

Prevalence and causes of low vision and blindness in the Extreme North Province of Cameroon, West Africa.

A survey to determine the prevalence and causes of blindness and visual impairment in the Extreme North Province of Cameroon was conducted in the Spring of 1992. A total of 10,647 people age 6 years and older was selected from a multi-stage, clustered sample stratified by ecological zone. The subjects were examined by ophthalmologist-led teams for visual acuity and ocular diseases. Approximately 1.2% of the sample was bilaterally blind by the World Health Organization classification (Category 3) of vision less than the ability to count fingers at 3 meters. Similarly to results found in other developing countries, senile cataract was the most common diagnosis encountered and the most frequent principal cause of low vision and blindness.

Adolescent↗
PubMed1995

Inducible nitric oxide synthase gene expression in brain following cerebral ischemia.

Cerebral ischemia is followed by a local inflammatory response that is thought to participate in the extension of the tissue damage occurring in the postischemic period. However, the mechanisms whereby the inflammation contributes to the progression of the damage have not been fully elucidated. In models of inflammation, expression of the inducible isoform of nitric oxide synthase (iNOS) is responsible for cytotoxicity through the production of large amounts of nitric oxide (NO). In this study, therefore, we sought to establish whether iNOS is expressed in the ischemic brain. Rats were killed 6 h to 7 days after occlusion of the middle cerebral artery. iNOS expression in the ischemic area was determined by reverse-transcription polymerase chain reaction. Porphobilinogen deaminase mRNA was detected in the same sample and used for normalization. In the ischemic brain, there was expression of iNOS mRNA that began at 12 h, peaked at 48 h, and returned to baseline at 7 days (n = 3/time point). iNOS mRNA expression paralleled the time course of induction of iNOS catalytic activity, determined by the citrulline assay (17.4 +/- 4.4 pmol citrulline/micrograms protein/min at 48 h; mean +/- SD; n = 5 per time point). iNOS immunoreactivity was seen in neutrophils at 48-96 h after ischemia. The data provide molecular, biochemical, and immunocytochemical evidence of iNOS induction following focal cerebral ischemia. These findings, in concert with our recent demonstration that inhibition of iNOS reduces infarct volume in the same stroke model, indicate that NO production may play an important pathogenic role in the progression of the tissue damage that follows cerebral ischemia.

Amino Acid Oxidoreductases↗
PubMed1995

Association of infantile neuroaxonal dystrophy and osteopetrosis: a rare autosomal recessive disorder.

The association of neuroaxonal dystrophy and osteopetrosis is reported in 2 siblings born to non-consanguineous parents. The 1st child was diagnosed as having infantile osteopetrosis shortly after delivery. A computed tomography scan of the head revealed agenesis of the corpus callosum. She died at the age of 9 months. Post-mortem examination showed pneumonia and bony sclerosis. Neuropathological examination revealed cerebral atrophy, ventricular dilation, absence of the corpus callosum, and a small hippocampus. Neuroaxonal spheroids were found in hippocampus, basal ganglia, pons, medulla, spinal cord, cranial nerves, cerebellum, and peripheral nerves. Ultrastructural examination revealed membranous cytoplasmic bodies and electron-dense granular deposits within the neuroaxonal spheroids as well as the soma of neurons. The 2nd child was delivered at 36 weeks of gestation because of intrauterine fetal distress. The diagnosis of osteopetrosis and partial agenesis of the corpus callosum was made shortly after delivery. The child died at 1 month without an autopsy. There are rare cases reported previously with the association of neuroaxonal dystrophy and osteopetrosis. We review these cases and compare them with ours.

Agenesis of Corpus Callosum↗
PubMed1995

Phenylketonuria screening: effect of early newborn discharge.

OBJECTIVE: To determine the percentage of term newborns discharged by 24 hours of life and the actions taken by physicians and institutions to avoid false-negative phenylketonuria (PKU) screens in these infants. DESIGN: Descriptive cross-sectional survey. PARTICIPANTS: One hundred forty term nurseries and 157 pediatricians. SELECTION PROCEDURE: Stratified sampling techniques were used to sample nurseries from the 1992 American Hospital Association guide to provide equal representation of each region of the country. Pediatricians were systematically sampled from a national list of practicing pediatricians supplied by Ross Laboratories to provide equal sampling from each state. RESULTS: The response rates were 95% (n = 133) for term nurseries and 83% (n = 131) for pediatricians. Twenty-four percent of healthy newborns are discharged by 24 hours of life. Ninety-three percent of nurseries screen all infants for PKU before discharge. In states without laws mandating rescreening, only 48% of institutions that discharge the majority of their infants (> 50%) by 24 hours of life rescreen. Also, in states without rescreening laws, 64% of pediatricians rescreen. The timing of this repeat screen ranges from less than 72 hours of life to 4 weeks. Determining which infants to rescreen varies by practitioner; some rescreen all infants, whereas others rescreen those discharged early. Just more than half of all pediatricians, whether practicing in a state requiring repeat PKU screening, claim to be familiar with the American Academy of Pediatrics recommendations regarding repeated PKU screening of infants discharged by 24 hours of life. CONCLUSION: Twenty-four percent of term newborns in the United States are discharged by 24 hours of life. Most hospitals screen all infants for PKU before discharge regardless of age. The majority of states do not mandate rescreening; rescreening policies among pediatricians and institutions in those states vary widely. A significant number of infants do not receive repeated screening and are therefore at risk for delayed or missed diagnosis of PKU because of insensitive initial screens. Pediatrician awareness of the need to perform repeated PKU screens on infants discharged by 24 hours is poor.

Age Factors↗
PubMed1995

Universal hepatitis B immunization.

OBJECTIVE: To determine the practices of US nurseries, neonatal intensive care units (NICUs), and pediatricians regarding universal hepatitis B vaccination. DESIGN: Descriptive cross-sectional survey. PARTICIPANTS: One hundred forty term nurseries, 152 NICUs, and 157 pediatricians. Selection procedure. Nurseries and NICUs were systematically sampled from the 1992 American Hospital Association Guide to provide equal sampling from each region of the country. Pediatricians were systematically sampled from a national list of practicing pediatricians supplied by Ross Laboratories to provide equal sampling from each state. RESULTS: The response rates were 95% (n = 133) for term nurseries, 95% (n = 144) for NICUs, and 83% (n = 131) for pediatricians. Sixty-two nurseries (47%) provide routine hepatitis B vaccine (HBV) to their infants. Eighty-five NICUs (59%) routinely vaccinate their preterm infants; 62 (73%) initiate the series just before discharge; and 11 (13%) do so at birth. Principal reasons for not vaccinating include cost and a preference to allow the primary-care physician to initiate the series. One hundred ten (85%) pediatricians provide universal hepatitis B vaccination. Principal reasons for not vaccinating include cost and parents opting against vaccination. CONCLUSIONS: More than half of NICUs provide HBV routinely to their preterm infants, predominantly just before hospital discharge. A minority of NICUs are initiating vaccination at birth, which may provide suboptimal seroconversion. Although less than half of participating term nurseries are routinely vaccinating before discharge, 85% of pediatricians do initiate HBV by two months of age. The principal reasons for not providing vaccine are financial.

Cross-Sectional Studies↗
PubMed1994

Structure of the Pisum sativum seed lipoxygenase gene lox1:Ps:3.

We have isolated the Pisum sativum (pea) lox1:Ps:3 gene which encodes a lipoxygenase that is 84% identical in coding sequence to the LOX-3 gene from Glycine max (soybean). The 10028 bp sequence includes 5895 bp 5' to the transcription start site and 707 bp 3' to the stop codon. The coding region of lox1:Ps:3 contains eight introns, at positions equivalent to those in the soybean LOX-3 and L-4, the Phaseolus vulgaris (Frenchbean) LOX1, and the Pisum sativum lox1:Ps:2 genes. The first intron is unusually small. The 5'-flanking sequence contains two regions that have the potential to form hairpin structures, but few motifs known to interact with transcription factors. Despite their similarity in terms of expression, the lox1:Ps:3 and lox1:Ps:2 genes have little similarity within their 5'-flanking regions.

Genes, Plant↗
PubMed1994

Experiences and reflections of former pediatric chief residents.

OBJECTIVE: To compare actual and ideal time commitments of pediatric chief residents between 1972 and 1992 and to determine if actual time commitments have changed. DESIGN: Descriptive, cross-sectional survey. PARTICIPANTS: One thousand two hundred eighty-four former pediatric chief residents. RESULTS: Chief residents between 1972 and 1982 spent a greater percentage of time teaching and providing patient care than chief residents between 1983 and 1992. Chief residents between 1983 and 1992 spent a greater percentage of time scheduling and performing other administrative tasks. In general, chief residents desired more time to teach, to conduct research, and to provide outpatient care and desired less time for scheduling and for performing other administrative duties. CONCLUSIONS: Although chief residents desire to spend more time teaching and less time performing administrative tasks, administrative duties have increased at the expense of teaching and patient care responsibilities over the past 20 years.

Career Choice↗
PubMed1994

Isolation of a pea (Pisum sativum) seed lipoxygenase promoter by inverse polymerase chain reaction and characterization of its expression in transgenic tobacco.

Part of the 5'-flanking sequence of a pea (Pisum sativum) lipoxygenase (LOX) gene was cloned, after amplification from genomic DNA by inverse polymerase chain reaction. Translational and transcriptional fusions of 818 bp of the 5'-flanking region and its deletion derivatives (-513 and -356) were made to a beta-glucuronidase (GUS)-coding sequence and introduced into tobacco. Analysis of T1 transformants showed that the 818 bp 5'-flanking sequence drove GUS expression in seeds that was temporally regulated in a fashion similar to the accumulation of LOX mRNA in developing pea seeds. Contrary to expectations, however, expression of the 818 bp promoter-GUS fusion was not seed-specific; GUS activity was highest in leaves and also present in stems and, to a lesser extent, roots. Deletion analyses identified the region between -818 and -513 as essential for high-level, temporally regulated expression in seeds and also indicated that the sequence between -513 and -356 plays a negative role in leaf/stem, but not seed, expression. Comparison of translational and transcriptional fusions indicated that the LOX initiation codon was used more efficiently than the GUS initiation codon by the tobacco leaf translational apparatus.

Base Sequence↗
PubMed1994

Prevalence of lead poisoning in an urban cohort of infants with high socioeconomic status.

The purpose of this study was to assess the prevalence of lead poisoning in an urban cohort of infants with high socioeconomic status and to determine the usefulness of the Centers for Disease Control (CDC) questionnaire in predicting lead poisoning. The CDC questionnaire was administered to consecutive parents of infants, beginning with their 6-month well-child visit. All infants had a venous lead level by 12 months of age. The 165 infants were between 5.9 and 12 months (mean = 9.4 months). The majority (67%) lived in a major city, had parents who were college graduates (67%), and had private medical insurance (85%). The overall prevalence of lead poisoning (Pb > or = 10 micrograms/dL [0.483 mumol/L]) was 29%. The relative risk of lead poisoning, given exposure as defined by the CDC instrument, was 0.99 (95% CI = .81 to 1.21). The sensitivity and specificity of the questionnaire were 40% and 60%, respectively. We conclude that the prevalence of lead toxicity and the poor sensitivity of the CDC questionnaire in this cohort of urban infants with high socioeconomic status support the 1991 CDC recommendation for universal lead screening in this region.

Centers for Disease Control and Prevention, U.S.↗
PubMed1994

An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan.

OBJECTIVE: To determine whether L-5-hydroxytryptophan (L-5-HTP) associated with eosinophiliamyalgia syndrome (EMS) like illness contains impurities in a fashion similar to that described in L-tryptophan associated with EMS. METHODS: Members of a family who became ill after exposure to L-5-HTP were evaluated at the National Institutes of Health. Data from patients with extended exposure to L-5-HTP were also examined. Samples of L-5-HTP were examined using high performance liquid chromatography. RESULTS: One member of the family had EMS, and 2 others had eosinophilia. No patient in the other group reviewed developed the syndrome, although 2 patients developed eosinophilia. The L-5-HTP used by the family contained an impurity not present in samples from the other patient group. After replacement with L-5-HTP not containing this impurity, eosinophilia in 2 family members resolved. CONCLUSION: Some L-5-HTP contains impurities that may be related to L-5-HTP associated EMS.

5-Hydroxytryptophan↗
PubMed1994

Potential impact of linking an emergency department and hospital-affiliated clinics to immunize pre-school-age children.

OBJECTIVE: To determine whether the use of an urban pediatric emergency department (ED) to immunize pre-school-age children would result in an improvement in the percentage fully vaccinated by the end of the second year of life. DESIGN: A retrospective cohort study of two groups: (1) 100 consecutive children (ED group) enrolled at one of two hospital-affiliated primary care clinics were chosen from the ED patient logs if their second birthday occurred in the 12 months prior to November 1990; and (2) 91 age-matched control children (control group) were chosen at random from the same hospital-affiliated clinics' enrollment logs without regard to ED use. The health care provided during the first 2 years of life for each group was compared. RESULTS: The mean number of visits to the ED in the first 2 years of life by the ED group was significantly greater than that of the control group (2.9 [SD] +/- 2.5 vs 1.1 +/- 1.4; P < .001) during the first 2 years of life. In 67% of ED visits, children would have been well enough to receive a vaccination. Both groups had similar types and numbers of visits to the primary clinics. For example, the ED group had 10 +/- 5 visits by age 2 years compared with the control group, which had 9 +/- 4 visits. There was no significant difference in actual immunization percentages achieved in the clinic, with 62% of the ED group having received four diphtheria, pertussis, and tetanus vaccinations; three oral poliovirus vaccinations; and one measles, mumps, and rubella vaccination by age 2 compared with 69% of control children. There were more missed vaccination opportunities during clinic visits in the ED group (7.4 vs 4.6 per 100 clinic visits; P < .01). If immunizations were offered in the ED to those children who needed them, immunization percentages would have been increased an average of 20% compared with percentages achieved in the clinic alone. CONCLUSION: Routine vaccinations in the ED would significantly increase immunization percentages in children enrolled in two hospital-affiliated clinics. Close linkage and coordination between the ED and hospital-affiliated clinics may improve preventive health care in urban children who use EDs.

Child Health Services↗
PubMed1993

Association of reported infant crying and maternal parenting stress.

Infant crying is a well-recognized source of parental concern and anxiety, but little is known about other possible effects of excessive crying on parents or caretakers. The objective of this descriptive study was to investigate the relationship between reported infant crying and parenting stress. Mothers, who were consecutively enrolled at the time of their infants' well-child checkups, reported the number of minutes their infant generally cried in a 24-hour day. Excessive crying was defined as more than three hours per 24-hour day. Seventy-five of 94 mothers subsequently completed the Parenting Stress Index (PSI) at their infant's 4- or 6-month checkup. Mothers who reported excessive crying were 5.7 times more likely to score high on the reinforcement subscale of the PSI. Although the direction of this association is not known, it indicates that mothers who report excessive crying are more likely than other mothers to perceive a lack of positive reinforcement from their infants.

Adult↗