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Biomedical subjects

N Klein

Publications and source records attributed to N Klein.

At least 109 records · Page 6Linked to original sources
PubMed1991

Bias against negative studies in newspaper reports of medical research.

OBJECTIVE: --To assess if the reporting of controversial medical journal articles by newspapers reflects the existence of a bias against negative studies (those showing no effect), we compared the rates of newspaper reporting of two studies, one negative and one positive, published back-to-back in the March 20, 1991, issue of JAMA. Both studies analyzed an area of public health concern, radiation as a risk for cancer. DESIGN: --Seven computerized on-line databases were screened for daily newspapers published in North America during the week following JAMA's publication of the two studies. These databases had full-text access to 168 daily newspapers. Newspapers identified with reports of the two studies were analyzed for length and quality of the reports. RESULTS: --Seventeen newspapers, publishing 19 reports on the two studies, were identified. Nine reports were dedicated solely to the positive study and 10 reports covered both studies. None of the reports were dedicated to the negative study only. In reports covering both studies, the mean length of the positive reports was significantly longer than the mean length of the negative reports (354 +/- 181 words vs 192 +/- 178 words; P = .04). The mean quality score of the positive reports was significantly higher than that of the negative reports (10.1 +/- 3.4 vs 5.9 +/- 4.9; P = .02). CONCLUSIONS: --The number, length, and quality of newspaper reports on the positive study were greater than news reports on the negative study, which suggests a bias against news reports of studies showing no effects or no adverse effects.

American Medical Association↗
PubMed1991

Effect of very low birth weight and subnormal head size on cognitive abilities at school age.

BACKGROUND: We tested the hypothesis that very-low-birth-weight (less than 1.5 kg) infants with perinatal growth failure whose head size is not normal by eight months of age (corrected for prematurity) have significantly poorer growth and neurocognitive abilities at school age than very-low-birth-weight children with a normal head size at eight months. We also hypothesized that these differences would persist even after control for major neurologic impairment and perinatal and sociodemographic risk factors. METHODS: We have followed a cohort of very-low-birth-weight children since their birth during the period 1977 to 1979. At eight to nine years of age 249 children were evaluated with a neurologic examination and tests of intelligence; receptive and expressive language skills; speech, reading, mathematics, and spelling aptitude; visual and fine motor abilities; and behavior. Ages were corrected for premature birth. RESULTS: Among these 249 very-low-birth-weight children, head size was subnormal (less than the mean -2 SD for age) at birth in 30 (12 percent), at term in 57 (23 percent), and at eight months in 33 (13 percent). As compared with the 216 children with normal head sizes, the 33 children with subnormal head sizes at the age of eight months had significantly lower mean birth weights (1.1 vs. 1.2 kg) and higher neonatal risk scores (71 vs. 53) and at the age of eight years had a higher incidence of neurologic impairment (21 percent vs. 8 percent) and lower IQ scores (mean verbal, 84 vs. 98). Even among the children without neurologic abnormalities, a subnormal head size at eight months of age was predictive of poorer verbal and performance IQ scores at eight years of age; lower scores for receptive language, speech, reading, mathematics, and spelling; and a higher incidence of hyperactivity. In multiple regression analyses to control for socioeconomic and neonatal risk factors, intrauterine growth failure, birth weight, and neurologic impairment, a subnormal head size at eight months of age had an independently adverse effect on IQ and on scores for receptive language, speech, reading, and spelling. CONCLUSIONS: In very-low-birth-weight infants, perinatal growth failure, as evidenced by a subnormal head circumference at eight months of age, is associated with poor cognitive function, academic achievement, and behavior at eight years of age.

Cephalometry↗
PubMed1991

A follow-up of female delinquents: maternal contributions to the perpetuation of deviance.

Twenty-one female delinquents, neuropsychiatrically evaluated while in a juvenile correctional facility, were followed up to 7 to 12 years later. Compared with a matched sample of male delinquents, they committed fewer and less violent offenses. Unlike the males, early biopsychosocial variables were not predictive of adult criminality; however, most females were seriously impaired neuropsychiatrically. Mortality rates were high. Having come from abusive households, the female delinquents became suicidal, alcoholic, drug addicted, enmeshed in violent relationships, and unable to care for their children.

Adolescent↗
PubMed1989

Dissociation between reperfusion induced arrhythmias and increases in ventricular alpha 1 receptor density in the anaesthetised rat.

Using anaesthetised rats we have assessed (1) whether the density of alpha 1 adrenergic receptors increases during coronary artery occlusion, (2) whether any change in density can be associated with the onset of reperfusion induced ventricular fibrillation, and (3) whether alpha 1 blockade with prazosin modifies the incidence of reperfusion induced ventricular fibrillation. The incidence of fibrillation upon reperfusion after 3, 5, 10, 20 and 30 min occlusion was 20, 75, 50, 16 and 10% (n = 10-12 in each group) respectively. alpha 1 Receptor density was measured using [3H]-prazosin in non-ischaemic and ischaemic tissue obtained after 0, 5 and 30 min ischaemia. Receptor density was not significantly altered at the time of maximum incidence of reperfusion induced ventricular fibrillation (5 min occlusion) but did significantly increase in both non-ischaemic and ischaemic tissue after 30 min occlusion, when the incidence of fibrillation upon reperfusion was very low (8%). At this time the values were 17.0(SEM 2.3) and 18.4(0.6)fmol.mg-1 protein in non-ischaemic and ischaemic zones as compared to 10.7(0.6) and 12.8(1.0)fmol.mg-1 protein in sham operated control animals (p less than 0.05 in both cases). Prazosin (0.1 or 1.0 mg.kg-1 body wt intravenously, 5 min prior to coronary occlusion) did not alter the incidence of ventricular fibrillation, ventricular tachycardia or total number of premature ventricular complexes upon reperfusion. We conclude that ischaemia induced changes in alpha 1 receptor density do not parallel changes in vulnerability to reperfusion induced arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

[Relationship between the development of the health status and the activity of the health care system in developed countries].

The question of the relationship between the evolution of health status and the activity of health care system in developed countries is treated frequently through epidemiological studies. However, there are numerous methodological difficulties linked to this type of investigation and it is not possible to give a certain answer to this question. Particular difficulties concern the choice of indicators (indicators of health status and indicators of health care system). This choice may influence largely the outcome of the results. If general mortality has tended to decline over the last thirty years, some causes of death have progressed and many studies show an increase of the level of morbidity and disabilities declared in the population and an increase of social disparities in health status. The analysis concerning the role of health care systems, in order to explain this evolution, does not lead to a single conclusion. Some works show the positive effect of the activity of health care systems (especially for infant mortality). According to other authors, the growth of chronic diseases must be considered as the negative aspect of the success obtained in the struggle against mortality. But above all, interpretation of results needs a continuous reference to methodologies used and it is only on this condition that such data may be useful for public health decisions.

Aged↗
PubMed1988

Sepsis of the hip in paraplegic patients.

For the treatment of chronic sepsis of the hip in paraplegic patients, we adopted three measures: (1) a Girdlestone procedure, (2) transposition of the vastus lateralis muscle into the void that was left by the removal of the femoral head and neck and the acetabular wall, and (3) external fixation to prevent unrestrained motion of the femoral shaft, which might damage the transposed muscle. The hip joint was spanned by a posterior pelvic-femoral skeletal external fixator. Nine patients, all of whom had thoracic-level paraplegia, were treated in this manner. The fixator was kept in place for three to six weeks while the patients were cared for in the prone position. All of the infections were fully healed by twelve weeks postoperatively. In two patients, the wound drained at the edge of the flap for a short time.

Adult↗
PubMed1987

Marital therapy outcome measured by therapist, client, and behavior change.

The present research examined marital therapy outcome, in a sample of 88 couples and 22 therapists, through the use of multidimensional criteria from multiple perspectives. Three paper-and-pencil patient self-report instruments were used to measure different aspects of the couple relationship. In addition, therapist post-therapy ratings and objective observer ratings of the couple behavior during therapy were obtained. Past debates about what the "right" criteria might be for measuring therapeutic change prompted our strategy. Special attention was focused on those criteria that could be classified as "inside" or "outside" of the couple relationship. Data analysis revealed a significant relationship between the couples' and therapists' ratings of improvement in therapy. Additionally, husband and wife negative acts (behaviors) in therapy were also significantly correlated with therapists' ratings of improvement. Both statistically significant and clinically significant criteria were employed to evaluate the therapy outcome. Improvement due to therapy as measured by the three self-report instruments varied from 38% to 58%. These differences appeared to stem from the different kinds of information yielded by the specific tests.

Adult↗
PubMed1986

Calcium-channel blockers for combined angina pectoris and systemic hypertension.

Calcium-channel blockers have been successfully used in the treatment of angina of effort and systemic hypertension. Many patients present with concomitant angina pectoris and hypertension. Controlled clinical trials demonstrate that the calcium-channel blockers are safe and effective as monotherapy in the treatment of these patients, and that their use compares favorably with that of propranolol. The effectiveness of these agents in hypertension appears to be primarily due to their ability to induce systemic vasodilation. Calcium-channel blockers have several therapeutic effects in angina pectoris. Beneficial actions on the major determinants of oxygen consumption, i.e. heart rate, blood pressure and contractility, are generally seen. The potent coronary vasodilating actions of these agents allow for increased coronary blood flow. Improvements in ventricular compliance, regression of left ventricular hypertrophy and cardioprotection appear to be additional effects of the calcium-channel blockers; their contribution to the drugs' overall therapeutic efficacy is presently being evaluated. Calcium-channel blockers are a welcome addition to drug regimens available for the management of patients with coexisting angina pectoris and hypertension.

Adult↗
PubMed1985

Lidoflazine and propranolol combination treatment in chronic stable angina.

The short-term (1 month) and long-term (6 months) safety of combination lidoflazine-propranolol therapy was investigated in an open trial of 15 patients with stable angina of effort. The possible advantages of adding lidoflazine (titrated to 360 mg daily) to patients having a therapeutic response to propranolol (80-400 mg daily) was also evaluated. Effects on non-invasive indexes of left ventricular function (echocardiography, systolic time intervals, radionuclide ventriculography) and exercise tolerance (treadmill exercise testing) were determined. There was no change in mean resting heart rate with the combination therapy, although one patient developed sinus bradycardia at a rate of 44 and had to have his propranolol dose reduced. Electrocardiographic analysis showed significant prolongation of the QTc intervals on lidoflazine-propranolol therapy compared to propranolol alone, with 3 patients having QTc interval prolongation to above .53 seconds, but there was no evidence of increased arrhythmogenesis with the combination therapy compared to propranolol alone. Left ventricular end-diastolic volume index tended to rise with combination therapy. However, lidoflazine-propranolol therapy did not produce any significant effects on resting ejection fraction determined by M-mode echocardiography or by radionuclide ventriculography. Radionuclide ventriculography determined peak exercise ejection fractions were also not significantly changed with combination therapy compared to propranolol alone. There were only small, insignificant improvements in exercise tolerance with the lidoflazine-propranolol combination treatment compared to propranolol alone. It is concluded that lidoflazine-propranolol combination therapy is generally safe but has the potential of causing serious adverse effects in certain patients, i.e. those with sick sinus disease, prolonged QTc intervals, and severe baseline left ventricular dysfunction, and that caution must be exercised in its use. Furthermore, it would appear that combination therapy provides only slight, if any, improvements in exercise tolerance in patients with chronic stable angina having a therapeutic response to oral propranolol.

Adult↗
PubMed1985

Preschool performance of children with normal intelligence who were very low-birth-weight infants.

Children who were very low-birth-weight infants (less than 1,500 g), beneficiaries of modern neonatal intensive care, are now of school age. To evaluate their school performance 80 children born in 1976 who had very low-birth-weight (mean birth weight 1.2 kg, mean gestational age 30 weeks) were examined at age 5 years. Sixty-five children were neurologically intact and had normal IQ (greater than or equal to 85) on the Stanford-Binet; five children were neurologically abnormal and ten had IQ below 85. Of the 65 children with normal intelligence and no neurologic impairments, 46 were single births and enrolled in preschool. These 46 children were matched by race, sex, and family background with classmate control children who had been born at full term. Outcome measurements included the Slosson Intelligence Test, the Woodcock-Johnson Psycho-Educational Battery (including subscales of Picture Vocabulary, Spatial Relations, Memory for Sentences, Visual Auditory Learning, Quantitative Concepts, and Blending) and the Beery Developmental Test of Visual-Motor Integration. No significant differences in IQ were found between children who were very low-birth-weight infants and control children; however, children who were very low-birth-weight infants performed significantly less well on the Spatial Relations subtest of the Woodcock-Johnson and on the Visual-Motor Integration test. Similar results were found for nine sets of twins and their control children. Recognition of these perceptual and visual-motor problems may permit appropriate early remedial intervention and prevent the compounding of these difficulties.

Child Development↗
PubMed1985

Mental retardation, organic brain dysfunction, and the forensic clinician: some practical considerations.

Mental retardation as it is frequently interrelated with a variety of organic brain dysfunctions may present unclear clinical pictures. This has particular relevance for the forensic practitioner who often needs to present his findings to the court in a clearly demarcated manner. This paper outlines the more commonly encountered entities in this area with consideration to forensic science implications.

Attention Deficit Disorder with Hyperactivity↗
PubMed1984

The growth of olfactory neurons in short-term cultures of rat olfactory epithelium.

We have found that purified astrocytes will support the growth of olfactory epithelial neurons ( OENs ) in vitro. Candidate OENs were visible by light microscopy within one day after plating of dissociated cells from neonatal rat ethmoturbinates . Electron microscopy showed that OENs expressed the unique ultrastructural features which characterize these cells in situ, showing that regulation of neuronal morphology and ultrastructure can function independently of contact with other cells of the appropriate tissue. Characteristics of the cultures are such that this in vitro system would be useful in electrophysiological investigations of the chemosensory olfactory neurons.

Animals↗
PubMed1984

The relationship between therapist behaviors and outcome for middle- and lower-class couples in marital therapy.

Treated a sample of 77 distressed middle- and lower-class couples by 19 therapists using conjoint therapy. Batteries of tests that assessed marital satisfaction and communications skills were given pre- and posttherapy plus 3 and 6 months later. Couple and therapist therapy behavior were assessed using audio tapes of interview sessions. A variety of sex and social class differences were found that correlated with therapy outcome. The overall thrust of the findings suggests that no one marital therapy technique will be appropriate for the different sexes and with those of different SES backgrounds.

Adult↗