Search PubMed⌕ Search

Biomedical subjects

H L Needleman

Publications and source records attributed to H L Needleman.

At least 19 recordsLinked to original sources
PubMed2001

The relationship between dental overbite and eustachian tube dysfunction.

OBJECTIVE: The purpose of this study was to investigate the association between deep dental overbite and eustachian tube dysfunction (ETD). DESIGN: Case-control study. SETTING: Tertiary care pediatric otolaryngology outpatient clinic at the Children's Hospital, Boston, Massachusetts. PATIENTS: 105 patients between the ages of 2 and 6 years. STUDY MEASUREMENTS: Dental overbite, overjet, and occlusal relationships were measured by an observer who was unaware of ETD status. ETD was defined as having ventilation tubes in place or having the recommendation for ventilation tube placement by an attending pediatric otolaryngologist. In addition, demographic information and medical and social histories were prospectively recorded. RESULTS: In a multivariate logistic regression model, children with deep bites were 2.8 times more likely to have ETD than those without deep bites (P = .03). Other independent risk factors for ETD identified in this model were family history of otitis media (OM) and age less than 3 years. CONCLUSIONS: Children with deep dental overbites are at a significantly increased risk for developing ETD.

Child↗
PubMed2001

Studies of lead exposure and the developing central nervous system: a reply to Kaufman.

Kaufman's critique of the lead-cognition hypothesis is a reiteration of well worn and weary claims raised many times in the past, primarily by spokespersons for the lead industry. They have been fully rebutted in the literature. The essence of these claims is that those studies showing an association between lead and IQ are flawed by uncontrolled confounding, multiple comparisons, and errors in measurement. Any effect of lead, Kaufman asserts, if present, is small. This response examines each of these issues and shows that they lack substance. Lead's negative impact on IQ persists in most modern studies after confounding has been controlled in many different statistical models. At least three metaanalyses have confirmed an effect of lead at low dose. Animal studies in which lead is given systematically, and the issue of confounding thereby avoided, demonstrate an unequivocal lead effect at similar doses to the human studies. The criticism of multiple comparisons similarly does not withstand examination. Measurement errors are nonsystematic and nondifferential. They are, therefore, null biasing. The actual size of the lead effect has been shown to be substantial, and to be found most prominently at the ends of the distribution. Kaufman says that lead requires study of diverse dimensions of intellect, but he restricts his scope to a sample of studies of lead and IQ, ignoring recent high quality studies that show a clear lead effect, and in those studies that he critiques he ignores data that contradict his position. His article adds nothing to the dialogue on lead neurotoxicity.

Comment↗
PubMed2000

The removal of lead from gasoline: historical and personal reflections.

Tetraethyllead (TEL) was first fabricated for use in gasoline in 1923. Shortly after manufacture began, workers at all three plants began to become floridly psychotic and die. A moratorium on TEL production was put into place, but was lifted in 1926. Between 1926 and 1965, the prevailing consensus was that lead toxicity occurred only at high levels of exposure and that lead in the atmosphere was harmless. Most of the data on lead toxicity issued from a single source, the Kettering Laboratory in Cincinnati. In 1959, the first warnings of adverse health effects of lead at silent doses were raised by Clair Patterson, a geochemist. In hearings before the Senate Committee on Public Works, Senator Edward Muskie raised the question of adverse health effects from airborne lead. As new data accumulated on health effects of lead at lower doses, the movement to remove lead from gasoline gained momentum, and the Environmental Protection Agency examined the question. The removal of lead would take place over the next 25 years, and its accomplishment would require a severe change in the federal stance regarding its hazard. This article details the interaction of various forces, industrial, regulatory, judicial, public health, and public interest, that were engaged in this contest and estimates the value of this step.

Air Pollutants↗
PubMed2000

Bone lead levels and language processing performance.

The relation between bone lead absorption and language processing abilities in 156 randomly selected 11- to 14-year-old boys who were asymptomatic for lead toxicity is examined. Tibial lead concentrations were measured by X-ray fluorescence spectroscopy. The language processing outcome variables consisted of the least and most difficult subtests from the Nonword Repetition Task, Competing Language Processing Task, and the Revised Token Test. Participants were classified by quartiles according to bone lead concentrations, and analysis of variance and analysis of covariance measured the impact on language processing scores. Results showed that children in the highest bone lead quartile displayed decreased language processing performance on the most difficult language processing tasks but not on the easier tasks.

Adolescent↗
PubMed1998

Childhood lead poisoning: the promise and abandonment of primary prevention.

In 1991, the Public Health Service published the Strategic Plan for the Elimination of Childhood Lead Poisoning. This document marked a fundamental shift in federal policy from finding and treating lead-poisoned children to authentic primary prevention. It spelled out a 15-year strategy to achieve this goal and provided a cost-benefit analysis showing that the monetized benefits far exceeded the costs of abatement. A strong national effort to eliminate the disease developed. Now, 7 years after publication of the plan, primary prevention of lead exposure has been abandoned. This article examines the role of some prevailing attitudes and institutions in derailing the effort. Some institutions--the lead industry, real estate interests, and insurance interests--behaved as anticipated. Others, including private pediatricians, the American Academy of Pediatrics, some federal agencies, and a public interest group ostensibly dedicated to eliminating lead poisoning, also played an unexpected part in derailing the plan.

Attitude of Health Personnel↗
PubMed1997

Clamped in a straitjacket: the insertion of lead into gasoline.

In 1925, shortly after production of tetraethyl lead began, an outbreak of psychosis occurred in all three operating plants, and a number of workers died in acute mania. A temporary moratorium on the production of tetraethyl lead was imposed, and the Public Health Service convened a meeting of scientists, public health officials, and industrial representatives to investigate the safety of the product. This paper reviews the steps leading to the insertion of lead into gasoline, the response of industry to the tragic poisoning, the actions of the public health authorities to investigate the episode, and the forces that resulted in the restoration of the additive to gasoline.

Chemical Industry↗
PubMed1996

Bone lead levels and delinquent behavior.

OBJECTIVE: To evaluate the association between body lead burden and social adjustment. DESIGN: Retrospective cohort study. SETTING: Public school community. PARTICIPANTS: From a population of 850 boys in the first grade at public schools, 503 were selected on the basis of a risk scale for antisocial behavior. All of the 850 boys who scored in the upper 30th percentile of the distribution on a self-reported antisocial behavior scale were matched with an equal number drawn by lot from the lower 70% of the distribution. From this sample, 301 students accepted the invitation to participate. EXPOSURE MEASURE: K x-ray fluorescence spectroscopy of tibia at subjects' age of 12 years. MAIN OUTCOME MEASURES: Child Behavior Checklist (CBCL), teachers' and parents' reports, and subjects' self-report of antisocial behavior and delinquency at 7 and 11 years of age. RESULTS: Subjects, teachers, and parents were blind to the bone lead measurements. At 7 years of age, borderline associations between teachers' aggression, delinquency, and externalizing scores and lead levels were observed after adjustment for covariates. At 11 years of age, parents reported a significant lead-related association with the following CBCL cluster scores: somatic complaints and delinquent, aggressive, internalizing, and externalizing behavior. Teachers reported significant associations of lead with somatic complaints, anxious/depressed behavior, social problems, attention problems, and delinquent, aggressive, internalizing, and externalizing behavior. High-lead subjects reported higher scores in subjects' self-reports of delinquency at 11 years. High-lead subjects were more likely to obtain worse scores on all items of the CBCL during the 4-year period of observation. High bone lead levels were associated with an increased risk of exceeding the clinical score (T > 70) for attention, aggression, and delinquency. CONCLUSION: Lead exposure is associated with increased risk for antisocial and delinquent behavior, and the effect follows a developmental course.

Analysis of Variance↗
PubMed1996

Effects of blood lead levels on cognitive function of older women.

Elevated blood lead concentrations are known to have detrimental effects on neuropsychological function in both children and occupational cohorts of men and women. Although it is generally accepted that lead exposure at low levels is more dangerous for infants and children than for adults, the issue of the lowest level of exposure at which lead causes deleterious health effects in adults is yet to be solved. There is no available data on the role of lead exposure in cognitive dysfunction in nonoccupational cohorts of older persons. In the current study, we examined the cross-sectional relationship between blood lead levels and a variety of measures of neuropsychological function in a large cohort of elderly women recruited at both urban and rural sites. This study of elderly women demonstrates that blood lead levels as low as 8 micrograms/dl were significantly associated with poorer cognitive function as measured by certain neuropsychological tests. Even a slight decrement in cognition would have a large public health impact due to the large number of elderly at risk.

Adult↗
PubMed1995

Enamel hypoplasia, bilateral cataracts, and aqueductal stenosis: a new syndrome?

We report on a 12-year-old girl who presented with generalized enamel hypoplasia, cataracts, and enlargement of the cerebral ventricles secondary to aqueductal stenosis. Previously described syndromes of enamel defects with or without cataracts were excluded on the basis of clinical criteria and appearance of the dentition. Metabolic conditions which could have caused cataracts were excluded clinically and by biochemical tests. The combination of signs in this patient may represent a new syndrome.

Abnormalities, Multiple↗
PubMed1995

Behavioral toxicology.

The new fields of behavioral toxicology and behavioral teratology investigate the outcome of specific toxic exposures in humans and animals on learning, memory, and behavioral characteristics. Three important classes of behavioral neurotoxicants are metals, solvents, and pesticides. The clearest data on the deleterious effects of prenatal exposure to toxicants comes from the study of two metals, lead and mercury, and from epidemiological investigations of the effects of alcohol taken during pregnancy. Less complete data are available for two other groups of agents, solvents and pesticides. What we do know about their effects on the fetal brain is convincing enough to make us demand caution in their distribution.

Behavior↗
PubMed1995

Centronuclear myopathy and nursing pattern caries: management of a 1 year old.

The pathognomonic open mouth of centronuclear and other myopathies can also have implications for oral health. These patients are at greater risk for gingivitis, dental caries as a result of the mouth breathing and loss of lip seal. Low tongue posture may impede the lateral expansion of the maxilla resulting in a constricted maxillary arch with resultant posterior crossbites and functional shifts. Excessive molar eruption may also occur, resulting in anterior open bites and increases in the anterior lower vertical height.

Anesthesia, Dental↗
PubMed1994

Preventing childhood lead poisoning.

Of all the neurotoxins, lead is the longest known and best understood. Because we know so much about what it does, where it is, and what is required to remove it from the presence of children, lead poisoning should also be one of the easiest diseases to eradicate. Despite this, progress in the primary prevention of childhood lead poisoning has been halting and erratic. In this paper, I outline the rapidly advancing state of knowledge on the epidemiology and toxicology of lead, examine some of the reasons for the gap between what is known and what has been accomplished, and outline the steps toward authentic primary prevention. Eradication of childhood lead poisoning is a realizable goal. Its importance is unquestioned; former Secretary of the Department of Health and Human Services Louis Sullivan declared in 1991 that it is the most serious environmental disease of North American children.

Child↗
PubMed1994

Childhood lead poisoning.

Substantial changes in the toxicology and epidemiology of lead have resulted in revisions in the definition of toxicity, and have altered estimates of the numbers of children at risk. As observational studies have increased their sample size, improved the sensitivity of their measurements, and polished epidemiological designs, concentrations of lead once thought to be harmless have been shown to have deleterious neurobehavioral consequences. Prevalence rates have changed in correspondence. Public policy has shifted from case finding to emphasizing primary prevention, the only appropriate strategy for this group of children. It is possible that the rate of the disease could be driven close to zero within two decades.

Brain Damage, Chronic↗
PubMed1994

Child abuse and neglect--recognition and reporting.

The dental profession has a legal, ethical and moral responsibility to report suspected cases of abuse and neglect. The risk to the child is significant. In non-fatal cases of abuse, 35 percent will be abused again within one year. To this end, dentists should discuss child abuse and neglect at staff meetings and establish office procedures if a case is identified. Encourage staff to discuss concerns they have regarding possible abuse they suspect in the office. Keep the child abuse hotline number or local agency responsible for receiving reports in the office rolodex. Abuse and neglect is a real problem in all neighborhoods and dentistry can make a difference.

Adolescent↗