Biomedical subjects

J L Merola

Publications and source records attributed to J L Merola.

6 recordsLinked to original sources

PubMed1992

Contraceptive compliance with a levonorgestrel triphasic and a norethindrone monophasic oral contraceptive in adolescent patients.

OBJECTIVE: This study was undertaken to assess the impact of two low-dose oral contraceptive pills on compliance and side effects in adolescent patients. STUDY DESIGN: The use of a levonorgestrel-containing triphasic pill (N = 114) was compared with that of a monophasic (1 + 35) norethindrone-containing pill (N = 110) at two different sociodemographic sites. RESULTS: No significant difference in compliance or pill satisfaction was observed between the pills. Socioeconomic factors were the overriding predictors of compliance. At 3 and 12 months of follow-up, there were significantly fewer complaints of overall side effects (p less than 0.001 and p = 0.004, respectively), breakthrough bleeding (p = 0.017 and p = 0.018), and pill amenorrhea (p = 0.002 and p less than 0.001) among users of the triphasic pill. Mean weight change at 12 months was +1.1 kg for the monophasic pill and -0.1 kg for the triphasic pill. All known pregnancies occurred among noncompliant city clinic patients. CONCLUSIONS: Adolescents experienced fewer side effects with the triphasic pill than with the monophasic one, but compliance was the same.

Adolescent↗

PubMed1990

Bacteremia in an ambulatory setting. Improved outcome in children treated with antibiotics.

We undertook a study of 414 bacteremic patients (167 with Haemophilus influenzae and 247 with Streptococcus pneumoniae bacteremia) to evaluate their clinical presentation, laboratory and clinical results, and subsequent outcomes. Patients with H influenzae bacteremia were more likely to have soft-tissue foci, poorer clinical appearance at presentation, and be at higher risk for subsequent serious focal infections, persistent bacteremia, and subsequent hospital admissions than patients with S pneumoniae. Patients with H influenzae bacteremia had a 21.1-fold increase in risk of meningitis (95% confidence interval [CI] of 3.8 to 78.0) compared with those with S pneumoniae. The odds ratio for initial lumbar puncture was 5.25 (95% CI [1.1-23.6]). Ambulatory patients treated with antibiotics at presentation were less likely to develop new serious soft-tissue infections, persistent bacteremia, or to require subsequent hospital admissions than untreated patients. The effect of treatment was greater for patients with S pneumoniae than those with H influenzae. Careful follow-up and reevaluation of patients with presumptive bacteremia is essential because treated and untreated patients can still develop serious soft-tissue infections.

Adolescent↗

PubMed1990

The effect of task difficulty upon the extent to which performance benefits from between-hemisphere division of inputs.

The means by which the two hemispheres coordinate processing of information are not well understood. By means of a tachistoscopic paradigm, we have shown repeatedly that performance is better when two conflicting tasks are presented to separate hemispheres than when both tasks are presented to a single hemisphere. The present study examines whether this effect is restricted to a specific range of task difficulty. Adult right-handers viewed two conflicting naming tasks by means of a tachistoscope. Task difficulty was lowered by reducing processing load (Experiment I: N = 32). Task difficulty was raised by projecting a visual mask 40 ms after offset of the visual displays (Experiment II: N = 10). At lower levels of processing load, dividing conflicting tasks between the hemispheres was beneficial, but not significantly so. At higher levels of load, and at either higher or lower loads with a visual mask, there were significant benefits associated with dividing conflicting tasks between the hemispheres. Three alternative explanations are discussed for the absence of an advantage associated with between-hemisphere division of inputs when task difficulty is reduced.

Brain↗

PubMed1987

Developmental versus individual differences in the ability of the hemispheres to operate independently.

We have claimed that the ability to use the two cerebral hemispheres independently improves during early adolescence: Adults benefited from division of conflicting tasks between the hemispheres (Liederman & Meehan, in press; Merola & Liederman, 1987), whereas 10-year-old children did not (Merola & Liederman, 1985). The current research was undertaken to rule out the possibility that differences in the degree of hemispheric independence between adults and children were due to: (a) differences in overall performance or (b) differences in cognitive ability. The performance of ten adults was reduced to that of the 10-year-olds (by inserting a visual mask between trials). Nonetheless, 90% of the adults showed hemispheric independence, whereas only 50% of the children did. In addition, when high scholastic aptitude children were compared to adults, the difference in hemispheric independence remained. A causal model indicated that age and scholastic aptitude have unique effects upon hemispheric independence. Thus, there are both developmental and individual differences in the degree of hemispheric independence.

Adolescent↗

PubMed1985

Motor correlates of dichotic listening asymmetries in children.

The purpose of this study was to determine the predictive relation between incidence of unintended motor overflow and degree of asymmetry on a dichotic word identification task in children. Seventy-eight third grade girls and 67 fifth grade boys were seen longitudinally over a 2-yr period. Among girls, incidence of overflow, primarily contralateral, accounted for nearly 20% of the variance in dichotic listening scores; but the results were not reliable for boys. The findings support the contention that suppression of the non-dominant hemisphere is an important mechanism underlying dichotic listening performance.

Attention↗

PubMed1985

Developmental changes in hemispheric independence.

In this research, we questioned whether children's relative inability to use the 2 cerebral hemispheres independently contributes toward their difficulty with the simultaneous execution of conflicting tasks. 2 naming tasks were simultaneously presented to either 1 visual field/hemisphere combination (unilateral) or were divided between visual fields/hemispheres (bilateral). We predicted that bilateral presentation would improve performance by insulating these conflicting tasks from mutual interference and that there would be a developmental shift in the size of the advantage for bilateral presentation. This hypothesis was confirmed in a sample of 120 children (N = 40 per group). Older children (12- and 14-year-olds) named more items when they were presented bilaterally, rather than unilaterally, when conflicting inputs were directed to different hemispheres. Younger children (10-year-olds) displayed no advantage for bilateral presentation regardless of whether conflicting tasks were projected to the same hemisphere or different hemispheres. The fact that 10-year-olds did not benefit from division of conflicting inputs between the hemispheres was interpreted as a symptom of their relative inability to use the hemispheres independently.

Adolescent↗