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Biomedical subjects

E Shapiro

Publications and source records attributed to E Shapiro.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

Evaluation of regional load in acute ischemia by three-dimensional curvatures analysis of the left ventricle.

Geometric remodeling of the left ventricule (LV) following myocardial infarction and ischemic insult is associated with myocardial load redistribution. Regional curvatures based on 3-D reconstructions of the LV are used to calculate the regional loads. The technique uses surface normals to derive local circumferential and meridional curvatures. Following the validation of the procedure on simple geometric shapes, the effect of acute ischemia on the regional load redistribution was studied in six open chest dogs. Short axis magnetic resonance imaging (MRI) scans were used to reconstruct end-diastolic (ED) and end-systolic (ES) LV images by applying our helical shape descriptor, before and after acute coronary occlusion. Regional curvatures as well as local wall thickness by the volume element method were calculated before and after acute ischemia, and were used to approximate regional loads, by a regional stress index (sigma/P). Postmortem evaluation using monastral blue staining was used to divide each LV to normal (NZ), ischemic (IZ), and border (BZ) zones in the ischemic case, and to the anatomically matched regions in the preischemic LVs. Ischemia affects the local curvatures and loads both at ED and ES. At ED, sigma/P rose significantly only in the IZ. Similarly, at ES, the highest increase in load was detected in the IZ, but increases in circumferential and meridional load were seen in all regions. Identifying the load redistribution following acute ischemia helps delineate the mechanisms affecting geometric LV remodeling following myocardial infarction.

Animals↗
PubMedDate not supplied

Evaluation of the reported association of obsessive-compulsive symptoms or disorder with Tourette's disorder.

This review evaluates the evidence reporting an association of obsessive-compulsive symptoms (OCS) and obsessive-compulsive disorder (OCD) with Tourette's syndrome or disorder (TS). Published reports in the literature describing a relationship between OCS-OCD and TS provided the data for the review. The methodological adequacy of the studies are discussed and rated on five criteria: adequacy of the experimental sample, presence and adequacy of the control sample, whether tics are defined as OCS-OCD, whether blind procedures are used to diagnose OCS-OCD in subjects and controls, and evidence for the reliability and validity of OCS-OCD measures. Although there are considerable clinical indications suggesting an association of OCS-OCD with TS and chronic motor tic disorder (CMT), and a possible overlap between OSC-OCD and TS, our evaluation of the evidence does not provide adequate support for an association between these disorders. To meaningfully evaluate the possible relationship between OCS-OCD and TS requires development of specific criteria for classification of OCS-OCD-TS symptoms, use of adequate experimental and control samples, blind evaluation, reliable and valid measures of OCS-OCD-TS, and appropriate statistical analysis. If such studies are performed, it is possible that the strong relationship reported between OCS-OCD and TS is more likely to be artifact than fact, and recent bandwagon effect rather than the latest breakthrough.

Diagnosis, Differential↗
PubMedDate not supplied

Diazepam: how much better than placebo?

In a six week, double-blind, predictive, clinical study 224 neurotic and anxious outpatients were randomly assigned to treatment with diazepam (Valium) of placebo and weekly brief psychotherapy administered by experienced psychiatrists. Although diazepam was significantly more effective than placebo for the first week of treatment, it accounted for only 1-4% of the outcome variance, while nonspecific variables contributed 11-22%. After the first revisit and at endpoint, only nonspecific variables accounted for outcome variance ranging from 20 to 26% over the four outcome measures. According to physicians' global and scaled ratings of improvement, diazepam had a treatment advantage (p less than 0.01-0.05) over placebo at the end of the first week of treatment for both the total and completed samples, but not thereafter. According to patients' global ratings of improvement, diazepam was moderately superior (p less than 0.05) to placebo for the total sample only at the end of the first week of treatment and modestly better (p less than 0.10) than placebo for the completed sample on a highly reliable measure of reported anxiety at the same time point. However, patient ratings did not indicate an advantage for diazepam at any of the six points of observation on global ratings of improvement for the completed sample and on reported anxiety for the total sample.

Adult↗
PubMedDate not supplied

Sympathetic innervation of mammary glands mediates suckling-induced reflex inhibition of milk yield in rats.

Previous work has shown that physiologic activation of the sympathetic system may inhibit milk yield (ME) in rats. Thus, adrenal catecholamines (CAs) are released by suckling, but it is not known whether such inhibition results also from reflex activation by the same stimulus of neural sympathetics upon the mammary gland. The present experiments were designed to determine whether suckling inhibits ME induced by oxytocin (OT) in the urethane-anesthetized lactating rat, and whether such inhibition results from adrenal and/or neurally released CAs. Rats were isolated (6 h) from their pups and then anesthetized. OT (0.8 mU every 2 min) was administered intravenously to the mothers during suckling. Rats were either chronically implanted with cannulae into the lateral cerebral ventricles (intracerebroventricularly), bilaterally adrenalectomized (ADX), hypophysectomized (HX), spinal cord transected (SCT: T3-T4), or had the nipple area (NA) locally anesthetized before suckling. MEs were low in control, sham, ADX and HX rats, but not in rats given the beta-adrenergic blocker propranolol (PROP; intravenously or intracerebroventricularly injected), nor in SCT, NA or PROP-HX rats. As revealed by ductal resistance measurements as an indicator of ductal tone, suckling-induced inhibition of ME was due to ductal constriction within the mammary glands. These effects of suckling, however, could be prevented by prior activation of ductal mechanoreceptors. Together, these results indicate that suckling inhibits ME through the reflex activation of neurally mediated central beta-adrenergic mechanisms, and that these effects, in turn, can be regulated by ductal mechanoreceptor activation.

Adrenalectomy↗
PubMedDate not supplied

beta-adrenergic mechanisms modulate central nervous system effects of prolactin on milk ejection.

It is known that prolactin (PRL) is produced within the brain and numerous central actions of the hormone have been reported. In anesthetized lactating rats, central administration of PRL, i.e., intracerebroventricular (icv) or intrathecally (it), facilitated milk ejection (ME) by depressing the sympathetically mediated facilitatory tone of the mammary ductal system. However, it is not known whether or not the same effects and similar mechanisms take place in conscious rats after PRL administration. In the present study, the effects of centrally administered PRL, i.e., icv or it, on ME was determined in both conscious and anesthetized rats. In conscious rats, the rate of ME was determined by applying a 15-min period of suckling by the litter, following a 6-h period of isolation. In anesthetized rats, intramammary pressure (IMP) responses of the mammary glands to exogenous oxytocin (OT) were recorded. The results showed that, whereas in anesthetized rats, increased responsiveness of the mammary glands to OT were observed after PRL administration, an intense inhibition of ME occurred in conscious rats. Because, in conscious and anesthetized rats, these effects were prevented by prior administration of the beta-adrenergic blocker propranolol (PROP) to the mothers, this suggests that the PRL effects on ME are modulated through sympathomimetic and sympatholytic actions in conscious and anesthetized rats, respectively. Thus, as shown by ductal tone measurements, in conscious, but not in anesthetized rats, the effect of PRL was associated with increased ductal constriction within the mammary glands; an effect that was mimicked by icv administration of the beta-adrenergic agonist isoproterenol (ISOP) and that was prevented by PROP. Further, the sympatholytic action of icv-PRL in anesthetized rats prevented the effect on ductal tone of both icv-PRL in conscious rats and of ISOP in anesthetized rats. Taken together, these results clearly suggest that the central effects of PRL on ME are modulated by adrenergic mechanisms.

Anesthesia↗
PubMedDate not supplied

Measuring developmental outcomes of lead exposure in an urban neighborhood: the challenges of community-based research.

The Developmental Research on Attention and Memory Skills (DREAMS) Project measures developmental outcomes of approximately 330 children at risk for lead exposure within an ethnically diverse, inner-city neighborhood. This study is one project of the Phillips Neighborhood Healthy Housing Collaborative, a 6-year-old collaboration between residents of the Phillips community in Minneapolis, university researchers, and representatives of various public and private agencies. Our experience carrying out this research is used to highlight both the benefits of, and the challenges to, measuring exposure outcomes in inner-city children using a community-based research approach. Challenges to working within a community collaborative, to studying an ethnically diverse and economically disadvantaged neighborhood, and to utilizing neighborhood residents as project staff are discussed. The strategies used to address these issues are presented to offer ideas for surmounting the challenges inherent in community-based research. The investigation of community environmental health problems through a community-based research approach can result in improved methodology, enhanced quality of data collected, and increased effectiveness of data dissemination. In addition, it can lead to important findings that inform the scientific community and create positive community changes. It is paramount, however, that potential obstacles be anticipated and planned for, or else be detected early and promptly responded to, in a manner that preserves scientific rigor while respecting community needs and values.

Child, Preschool↗