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Biomedical subjects

E N Allred

Publications and source records attributed to E N Allred.

At least 55 records · Page 3Linked to original sources
PubMed1995

Hypocarbia before surfactant therapy appears to increase bronchopulmonary dysplasia risk in infants with respiratory distress syndrome.

OBJECTIVE: To determine to what extent the risk of bronchopulmonary dysplasia is affected by ventilatory management before the first dose of rescue artificial surfactant. STUDY DESIGN: Retrospective cohort study. SUBJECTS: One hundred eighty-eight low-birth-weight infants (< or = 1700 g) who received artificial surfactant therapy for respiratory distress syndrome and who were alive at 36 weeks of gestational age. OUTCOME: Bronchopulmonary dysplasia was defined by a need for supplemental oxygen to maintain an arterial saturation of 92% or more at 36 weeks of gestational age. RESULTS: Thirty-seven percent (70/188) of the cohort met study criteria for bronchopulmonary dysplasia. Early determinants significantly associated with bronchopulmonary dysplasia (given as odds ratio, 95% confidence interval) in the most parsimonious backward stepwise logistic regression model included the following: birth weight of 1000 g or less (5.1, 2.4 to 10.7), cesarean birth because of fetal distress (4.4, 1.7 to 11.4), ventilatory efficiency index of 0.15 or less before surfactant therapy (3.1, 1.4 to 6.8), arterial-alveolar oxygen ratio of 0.15 or less before surfactant therapy (2.2, 1.01 to 4.6), and a low arterial PCO2 (< or = 29 vs > or = 40 mm Hg, 5.6, 2.0 to 15.6; 30 to 39 vs > or = 40 mm Hg, 3.3, 1.3 to 8.3). The inverse relationship between hypocarbia and bronchopulmonary dysplasia persisted even in stratified analyses limited to infants with measures of cardiovascular or respiratory illness that suggested less severe manifestations of disease. CONCLUSIONS: Ventilatory management before rescue treatment with artificial surfactant therapy that result in hypocarbia may increase the risk of bronchopulmonary dysplasia. These findings suggest that early ventilatory management should not only provide adequate oxygenation but also limit hyperventilation.

Blood Gas Analysis↗
PubMed1995

Maternal metabolic control and risk of microcephaly among infants of diabetic mothers.

OBJECTIVE: To measure the incidence of microcephaly among infants of diabetic mothers (IDM) and assess its relationship to metabolic control during pregnancy. RESEARCH DESIGN AND METHODS: Head circumference data for 556 consecutive live-born singleton infants of women with insulin-requiring diabetes antedating pregnancy delivered between 28 and 40 weeks of gestation and the results of 3,242 HbA1 determinations collected during their pregnancies were examined. RESULTS: There were fewer head circumferences at or below the 3rd percentile and more at or above the 97th percentile than expected. Head circumference was not related to maternal metabolic control as documented by the HbA1 values. CONCLUSIONS: The less-than-expected incidence of microcephaly observed in this patient population probably reflects the well-known tendency of IDM toward macrosomia.

Adult↗
PubMed1994

Hymenal findings in adolescent women: impact of tampon use and consensual sexual activity.

We undertook a prospective study of 300 postmenarcheal female subjects (median age, 18.0 years) to examine (1) the relation of tampon use, sports participation, prior gynecologic examination, and consensual sexual activity to hymenal anatomy, (2) the factors leading to choice of tampons by girls not sexually active, and (3) factors related to ease of gynecologic examination. The sample included 100 subjects in group 1, who denied sexual intercourse and used only pads for menses; 100 subjects in group 2, who denied sexual intercourse and had used tampons; and 100 subjects in group 3, who gave a history of sexual intercourse. Sexually active subjects (81%) were significantly more likely than tampon users and pad users to have "complete clefts" in the lower hymen between the 2 o'clock and 10 o'clock positions (p < 0.001); tampon users were not significantly different from pad users (11% vs 5%). In subjects who were not sexually active, the presence of these complete clefts was not related to participation in sports or to prior pelvic examination. Although median hymenal opening diameter differed in the three groups (1.2 cm for group 1 vs 1.5 cm for group 2 vs 2.5 cm for group 3; p < 0.0001), the ranges of measurements were wide. Tampon users were significantly more likely than pad users to have mothers and friends, but not sisters, who had a favorable attitude toward tampon use. The best predictors of tampon use in a multivariate model were a favorable maternal attitude (odds ratio (OR), 5.3; 95% confidence interval (CI), 2.4, 12.1) and friends' use of tampons (OR 7.9; 95% CI 3.5, 18.1). Only 26% of speculum examinations in pad users were rated as easy compared with 56% of examinations in tampon users and 81% in sexually active young women (p < 0.001). The best predictors of ease of speculum examination were sexual activity (OR 15.9; 95% CI 1.9, 135.3) and tampon use (OR 3.6; 95% CI 1.0, 12.7). This large sample should provide useful data for physicians who testify in sexual assault cases and gives new information on the predictors of tampon use and ease of gynecologic examination in young women.

Adolescent↗
PubMed1994

Correlates of decaffeinated coffee choice.

We sought to identify the illness risk factors associated with consumption of decaffeinated coffee in a sample of 2,677 adults. Women who drank decaffeinated coffee exclusively were more likely than other women to consume vitamin supplements and cruciferous vegetables, to use seat belts routinely, and to exercise regularly. Among men, those who drank decaffeinated coffee exclusively were more likely than others to have a low body mass index and to consume a low-fat diet and cruciferous vegetables. We conclude that people who drink decaffeinated coffee differ from others in ways that might provide information about the risk of illnesses.

Adult↗
PubMed1994

Rapid noninvasive diagnosis and surgical repair of acute ascending aortic dissection. Improved survival with less angiography.

Angiography has been considered the gold standard for the diagnosis of acute dissection of the ascending aorta, but it may increase mortality by imposing an unnecessary delay before surgical repair. In addition, coronary angiography has often been considered essential as well. From 1988 to 1993, 37 patients (median age 61 years, 30 men and 7 women) had acute dissection of the ascending aorta. All of the initial 15 patients (group I) had angiography, even through the diagnosis of aortic dissection had already been made noninvasively in 14; six (40%) of 15 died, three of aortic rupture and none of complications of coronary artery disease. Among the next 22 patients (group II), 21 had a noninvasive diagnosis of acute dissection of the ascending aorta (eight by echocardiography; 13 by computed tomography), and 19 (86%) were operated on without angiography; two died (9%, p = 0.03 versus group I) and neither death was due to aortic rupture or coronary artery disease. Overall, either root or selective coronary angiography was attempted in 18 of 37 patients, but it documented coronary artery disease in only two patients (11%). Coronary artery disease was found in four other patents at autopsy; three of them, including two that died of aortic rupture, had angiography that failed to reveal the coronary artery disease. Noninvasive diagnosis of acute dissection of the ascending aorta is reliable and avoids the risks and delays inherent in invasive angiography. Rapid noninvasive diagnosis of aortic dissection and avoidance of routine angiography appear to improve survival by expediting surgical intervention and thus decreasing the risk of aortic rupture.

Acute Disease↗
PubMed1993

Pre- and postnatal low-level lead exposure and children's dysfunction in school.

The contributions of pre- and postnatal low-level lead exposures to the risk of learning problems were evaluated among 1923 children who were born in one Boston hospital in 1979-1980 and followed to age 8 years. In this relatively privileged group, more than 20% of the children had a mother with some formal postgraduate education. Prenatal lead exposure was estimated with a measurement of umbilical cord blood lead content, and postnatal lead exposure was approximated with measurement of lead in the dentin of an exfoliated deciduous tooth. Information about potential confounders and effect modifiers was obtained from maternal interview shortly after delivery and from a mailed questionnaire completed and returned when the child was approximately 6 years old. An assessment of each child's function in school was provided by the teacher, who completed a questionnaire near the end of the school year in which the child reached the age of 8 years. We considered a learning problem to be related to lead exposure if its adjusted prevalence increased with each loge increase in lead, and if the adjusted prevalence was elevated among children with high levels (i.e., approximating the highest decile) of umbilical cord blood lead (i.e., > or = 10 micrograms/dl) or dentin lead (i.e., > or = 5 micrograms/g). Girls with elevated umbilical cord blood lead levels were more likely than their peers to be dependent and inpersistent and to display an inflexible and inappropriate approach to tasks (defined as the "tasks" cluster). Boys with elevated umbilical cord blood lead levels were more likely than others to have difficulty with both simple directions and sequences of directions. Among girls, elevated deciduous tooth dentin lead content was associated with reading and spelling difficulties, the tasks cluster, and with "not functioning as well as peers." Elevated dentin lead levels were not overrepresented among boys with any of the assessed learning clusters. These findings are consistent with the inference that lead levels still prevalent among children (i.e., blood < 15 micrograms/dl) are associated with some learning problems in girls.

Child↗
PubMed1993

Human fetal compensatory renal growth.

The occurrence of prenatal compensatory renal growth has remained in question, despite the general acceptance of this phenomenon postnatally. We measured by ultrasound imaging the renal length of 22 human fetuses with a solitary kidney or contralateral multicystic dysplastic kidney, and compared it to measurements in 40 normal control fetuses. Renal length was normalized to fetal biparietal diameter. Analysis of covariance showed that the solitary kidneys were significantly larger than normal controls (p < 0.0001), although the rate of growth was not significantly increased above normal. These data document the presence of compensatory renal growth in human fetuses with solitary or functionally solitary kidneys.

Adaptation, Physiological↗
PubMed1993

Computed tomography imaging in children with head trauma: utilization and appropriateness from a quality improvement perspective.

Computed tomography (CT) imaging plays an important role in the acute evaluation and management of children with head trauma. When routine quality improvement (QI) meetings with representatives from the Children's Hospital radiology and emergency departments revealed disagreement regarding the utilization and appropriateness of CT in children presenting with head trauma, an interdepartmental QI team was formed to address this issue. Because formal criteria for obtaining CTs for head trauma were unavailable, internal institutional criteria were developed by consensus after literature review. Contrary to perceptions of some staff members, the majority (95%) of children who received CT met at least one of the established criteria over a one-year study period. There was little relationship between the presence of criteria and abnormal CT results, but decisions whether to admit patients to the hospital or to send them home were influenced by CT results. Follow-up studies suggested that patients who were discharged home with a normal CT or no CT had uniformly good outcomes.

Boston↗
PubMed1993

Sodium modeling ameliorates intradialytic and interdialytic symptoms in young hemodialysis patients.

Despite advances in the delivery of hemodialysis, significant dialytic morbidity persists. Sodium modeling in older adults has been shown to decrease some dialytic symptoms, but clear benefits in young patients without coexisting diabetes or advanced cardiovascular disease have not been shown. The effects of sodium modeling were evaluated in 16 adolescent and young adult hemodialysis patients (16 to 32 yr of age) treated with conventional hemodialysis for a median of 11.5 months. The 8-wk study was divided into four 2-wk blocks. During each block, one of three sodium programs or a constant (control) dialysate sodium of 138 mEq/L was used. During each sodium program, the initial dialysate sodium of 148 mEq/L was decreased by an exponential, linear, or step program to 138 mEq/L. Treatments with sodium modeling were significantly better than those with constant sodium dialysate. When all sodium programs were grouped and compared with constant dialysate sodium, the odds of improvement in dialytic cramps, headaches, and nausea were 1.8, 2.1, and 3.9, respectively (P < 0.05). Sodium modeling also significantly decreased the frequency of postdialysis hypotension and interdialytic fatigue, dizziness, and muscle cramping (P < 0.05). No differences were seen among the sodium protocols in the incidence of symptomatic hypotension, the amount of normal saline administered, the degree of hemo-concentration during treatments, or the decrease in serum osmolality. There was no increase in pretreatment or posttreatment serum sodium concentrations, interdialytic thirst, weight gain, or hypertension. Sodium modeling dramatically decreases both intradialytic and interdialytic morbidity in young hemodialysis patients. There was no increase in adverse events associated with sodium modeling.

Adolescent↗
PubMed1993

Antenatal corticosteroids appear to reduce the risk of postnatal germinal matrix hemorrhage in intubated low birth weight newborns.

OBJECTIVE: To determine to what extent the reduced risk in preterm newborns of intracranial hemorrhage attributed to antenatal corticosteroids (ANCS) reflects reductions in the incidence of respiratory distress and its correlates. METHODS: In a sample of 239 very low birth weight newborns recruited for a clinical trial of phenobarbital prophylaxis of subependymal/intraventricular hemorrhage, we explored the relationship between ANCS, the occurrence of germinal matrix hemorrhage (GMH) that first became evident after the 12th postnatal hour, and putative intervening variables such as acidosis, elevated peak inspiratory pressure, pneumothorax-pulmonary interstitial emphysema, and elevated continuous positive airway pressure. RESULTS: In multivariate models adjusting for confounders, newborns exposed to ANCS were at approximately one third the risk of GMH experienced by newborns not exposed to a full course of ANCS. The additions of measures and correlates of respiratory distress severity to these models did not change the GMH risk associated with ANCS. CONCLUSION: The GMH-protective effect of ANCS does not appear to be a consequence of enhanced pulmonary maturation.

Cerebral Hemorrhage↗
PubMed1992

Tumor angiogenesis: a new significant and independent prognostic indicator in early-stage breast carcinoma.

BACKGROUND: Axillary lymph node status has been the most important prognostic factor in operable breast carcinoma, but it does not fully account for the varied disease outcome. More accurate prognostic indicators would help in selection of patients at high risk for disease recurrence and death who are candidates for systemic adjuvant therapy. Our recent findings indicated that microvessel density (count or grade) in invasive breast carcinoma (a measure of tumor angiogenesis) is associated with metastasis and thus may be a prognostic indicator. PURPOSE: This study was designed to further define the relationship of microvessel density with overall and relapse-free survival and with other reported prognostic indicators in breast carcinoma. METHODS: In a prospective, blinded study of 165 consecutive patients, the microvessels within primary invasive breast carcinoma were highlighted by immunocytochemical staining to detect factor VIII-related antigen. Using light microscopy, we counted microvessels per 200x field in the most active areas of neovascularization and graded microvessel density. These findings were correlated, by univariate and multivariate analyses, with overall and relapse-free survival, axillary node status, and other prognostic indicators (median follow-up, 51 months). RESULTS: There was a highly significant (P < or = .001) association of microvessel density with overall survival and relapse-free survival in all patients, including node-negative and node-positive subsets. All patients with breast carcinomas having more than 100 microvessels per 200x field experienced tumor recurrence within 33 months of diagnosis, compared with less than 5% of the patients with breast carcinoma having 33 or fewer microvessels per 200x field. Moreover, microvessel density was the only statistically significant predictor of overall survival among node-negative women (P < .001). Only microvessel density (P < .001) and histologic grade (P = .04) showed statistically significant correlations with relapse-free survival in the node-negative subset. CONCLUSIONS: Microvessel density in the area of the most intense neovascularization in invasive breast carcinoma is an independent and highly significant prognostic indicator for overall and relapse-free survival in patients with early-stage breast carcinoma (I or II by International Union Against Cancer criteria). IMPLICATIONS: Such an indicator would be useful in selection of those node-negative patients with breast carcinoma who are at high risk for having occult metastasis at presentation. These patients could then be given systemic adjuvant therapy.

Adult↗
PubMed1992

Rate of bronchopulmonary dysplasia as a function of neonatal intensive care practices.

Some differences among neonatal intensive care units (NICUs) in incidence of bronchopulmonary dysplasia may reflect variations in medical care practices. After adjusting for differences in the inherent risk of bronchopulmonary dysplasia among 223 infants of less than 1751 gm birth weight who were admitted to three Harvard-affiliated NICUs, we used multivariate analysis to explore the extent to which medical care practices during the first days of life varied with the rate of bronchopulmonary dysplasia. In our analyses, variables were grouped by three major hypotheses: oxygen toxicity, barotrauma, and fluid overload. The NICU designated 1 (the one with the highest rate of bronchopulmonary dysplasia) used much higher than expected colloidal volumes during the first 4 days of life; in contrast, in the NICU designated 3 (the one with the lowest rate of bronchopulmonary dysplasia), infants consistently received lower than expected amounts of colloidal solution. Signs of patent ductus arteriosus were also much more frequent than expected during this time at NICU 1; rates were much lower than predicted at NICU 2 and were near predicted values at NICU 3. Maximum inspired oxygen fraction during the first 4 days varied significantly in a direction inconsistent with the oxygen toxicity hypothesis. Maximum arterial oxygen tension was significantly less than expected at the hospital with the lowest rate of bronchopulmonary dysplasia (NICU 3). None of six medical care practices indicating potential for barotrauma varied with NICU expect for positive end-expiratory pressure, which varied in a direction suggesting a protective effect against bronchopulmonary dysplasia. These findings agree best with the hypothesis that differences in hydration during the first days of life account for some of the difference among NICUs in bronchopulmonary dysplasia occurrence.

Bronchopulmonary Dysplasia↗
PubMed1991

The epidemiology of germinal matrix hemorrhage during the first half-day of life.

The personal and maternal characteristics of 27 babies with early-onset germinal matrix hemorrhage (EGMH) were compared with those of 280 babies with normal cranial ultrasonograms, studied in a separate clinical trial. None of the mothers of the babies with EGMH had high blood pressure or pre-eclampsia during pregnancy. Gestational age less than 30 weeks and initial pH less than 7.2 indicated increased risks of EGMH, and maternal receipt of steroids indicated reduced risk of EGMH. Thus prenatal and immediately perinatal factors appear to convey much of the information about the risk of EGMH.

Cerebral Hemorrhage↗
PubMed1991

Effects of carbon monoxide on myocardial ischemia.

The purpose of this study was to determine whether low doses of carbon monoxide (CO) exacerbate myocardial ischemia during a progressive exercise test. The effect of CO exposure was evaluated using the objective measure of time to development of electrocardiographic changes indicative of ischemia and the subjective measure of time to onset of angina. Sixty-three male subjects (41-75 years) with well-documented coronary artery disease, who had exertional angina pectoris and ischemic ST-segment changes in their electrocardiograms, were studied. Results from three randomized, double-blind test visits (room air, low and high CO) were compared. The effect of CO exposure was determined from the percent difference in the end points obtained on exercise tests performed before and after a 1-hr exposure to room air or CO. The exposures resulted in postexercise carboxyhemoglobin (COHb) levels of 0.6% +/- 0.3%, 2.0% +/- 0.1%, and 3.9% +/- 0.1%. The results obtained on the 2%-COHb day and 3.9%-COHb day were compared to those on the room air day. There were 5.1% (p = 0.01) and 12.1% (p less than or equal to 0.0001) decreases in the time to development of ischemic ST-segment changes after exposures producing 2.0 and 3.9% COHb, respectively, compared to the control day. In addition, there were 4.2% (p = 0.027) and 7.1% (p = 0.002) decreases in time to the onset of angina after exposures producing 2.0 and 3.9% COHb, respectively, compared to the control day. A significant dose-response relationship was found for the individual differences in the time to ST end point and angina for the pre- versus postexposure exercise tests at the three carboxyhemoglobin levels. These findings demonstrate that low doses of CO produce significant effects on cardiac function during exercise in subjects with coronary artery disease.

Adult↗
PubMed1990

The long-term effects of exposure to low doses of lead in childhood. An 11-year follow-up report.

To determine whether the effects of low-level lead exposure persist, we reexamined 132 of 270 young adults who had initially been studied as primary school-children in 1975 through 1978. In the earlier study, neurobehavioral functioning was found to be inversely related to dentin lead levels. As compared with those we restudied, the other 138 subjects had had somewhat higher lead levels on earlier analysis, as well as significantly lower IQ scores and poorer teachers' ratings of classroom behavior. When the 132 subjects were reexamined in 1988, impairment in neurobehavioral function was still found to be related to the lead content of teeth shed at the ages of six and seven. The young people with dentin lead levels greater than 20 ppm had a markedly higher risk of dropping out of high school (adjusted odds ratio, 7.4; 95 percent confidence interval, 1.4 to 40.7) and of having a reading disability (odds ratio, 5.8; 95 percent confidence interval, 1.7 to 19.7) as compared with those with dentin lead levels less than 10 ppm. Higher lead levels in childhood were also significantly associated with lower class standing in high school, increased absenteeism, lower vocabulary and grammatical-reasoning scores, poorer hand-eye coordination, longer reaction times, and slower finger tapping. No significant associations were found with the results of 10 other tests of neurobehavioral functioning. Lead levels were inversely related to self-reports of minor delinquent activity. We conclude that exposure to lead in childhood is associated with deficits in central nervous system functioning that persist into young adulthood.

Adolescent↗
PubMed1990

Childhood brain tumor: presentation at younger age is associated with a family tumor history.

In a registry-based sample of 361 children with a brain tumor, those whose grandparents and great-grandparents had a history of any kind of tumor were younger at the time of presentation than were those who lacked this family history (p = 0.1). In post hoc analyses, the age difference was most apparent among children with cerebral tumors, and when family history was limited to brain tumors and to great-grandparents. These findings are in keeping with the hypothesis that a familial tumor diathesis contributes to an early age at onset of a brain tumor in some children.

Age Factors↗
PubMed1990

Hydration during the first days of life and the risk of bronchopulmonary dysplasia in low birth weight infants.

We conducted a case-control study of antecedents of bronchopulmonary dysplasia (BPD) in 223 infants enrolled in a prospective, randomized clinical trial of phenobarbital prophylaxis for intracranial hemorrhage. The trial took place at three Boston neonatal intensive care units between June 1981 and April 1984. The 76 babies with BPD had radiographic evidence of the condition and required oxygen therapy for 28 days or more. All 147 control babies survived until day 28 of life without meeting either of these criteria for BPD. Compared with control infants, those with BPD received greater quantities of total, crystalloid, and colloid fluids per kilogram per day in the first 4 days of life. In addition, infants with BPD generally had a net weight gain in the first 4 days of life in contrast to the normal pattern of weight loss seen in control infants. Finally, the infants with BPD were more likely to be given a clinical diagnosis of patent ductus arteriosus and to have received furosemide on days 3 and 4 of life. From these observations we infer that early postnatal phenomena such as excessive fluid therapy may be important in the pathogenesis of BPD.

Blood Pressure↗