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Biomedical subjects

S Adler

Publications and source records attributed to S Adler.

At least 289 records · Page 16Linked to original sources
PubMedDate not supplied

Effect of acute and chronic hyponatremia on blood-brain barrier function in the rat.

To study whether acute or chronic hyponatremia alters blood-brain barrier (BBB) permeability, rats made hyponatremic by constant desmopressin acetate infusion were studied by NMR spectroscopy and imaging. On constant volume ventilation and nitrous oxide, acute (1- and 2-day) and chronic (7- and 14-day) hyponatremic and normonatremic controls were infused with 0.25 M HCl. Despite reducing blood pH by at least 0.35 in < 50 min, brain pH, measured by 31P NMR, was unaffected in any group. As a second test of BBB function, gadolinium-DTPA (Gd-DTPA) was injected intravenously in these five groups. Coronal slice 1H NMR images obtained before and after Gd-DTPA showed image intensity changes in multiple areas outside brain, but neither control nor hyponatremic rats showed any differences in cortex, white matter or cerebellum. To ascertain whether the threshold for BBB disruption was altered, hypertonic mannitol (1.5, 2.0 or 3.0 mL) was injected rapidly into one internal carotid artery and pre- and post-Gd-DTPA images obtained. In both control and hyponatremic rats only the largest dose caused detectable Gd-DTPA leakage into brain. Thus, BBB function appears intact in both acute and chronic hyponatremia since neither H+ nor GD-DTPA penetrated the barrier and resistance to mannitol disruption was unaffected by hyponatremia.

Acute Disease↗
PubMedDate not supplied

Supercritical carbon dioxide extraction of selected medicinal plants--effects of high pressure and added ethanol on yield of extracted substances.

The possibilities and limitations of supercritical fluid extraction of natural products of low, medium and high polarity under very high pressure and with polar modifiers has been investigated. The medicinal herbs marigold (Calendula officinalis), hawthorn (Crataegus sp.) and chamomile (Matricaria recutita) were used as models in this study. Extraction profiles and the spectra of extractable metabolites were recorded following extraction with mixtures of carbon dioxide:ethanol of varying proportions (0-20% ethanol) and at various pressures in the range 300-689 bar. Components were identified by HPLC-PAD-MS or GC-MS and quantified by HPLC or GC as appropriate. Extraction yields under the varying conditions depended to a large extent on the profiles of secondary metabolites present in the three drugs. Whereas the extractability of lipophilic compounds increased substantially at pressures above 300 bar, the yields of polyphenolic and glycosidic compounds remained low even at 689 bar and with 20% modifier in the extraction fluid.

Calendula↗
PubMedDate not supplied

Psychopathology following cardioverter defibrillator implantation.

Previous reports have found elevated rates of psychopathology in recipients of implantable cardioverter defibrillators (ICDs). Thirty-five consecutive ICD recipients were assessed by using the Structured Clinical Interview for DSM-III-R and a semistructured questionnaire; assessments were performed within 3 days of ICD implantation (Time 1) and again 9-18 months later (Time 2). At the initial assessment, alcohol dependence in remission was the most common diagnosis, followed by mood disorders. Two cases of depression were found at follow-up assessment, but those subjects had either a lifetime history of major depression or some depressive symptoms at Time 1. No new cases of anxiety disorders were seen at Time 2. It appears that ICD recipients have rates similar to the general population at the time of implantation, and the risk for new psychopathology is largely confined to those with a lifetime history of psychopathology.

Adaptation, Psychological↗
PubMedDate not supplied

Attitudes toward menopause and aging across ethnic/racial groups.

OBJECTIVE: Attitudes have a potential role to play in the experience of menopause. The objective of this study was to examine the degree to which attitudes toward menopause and aging vary across ethnic groups and menopausal status (ie, premenopausal through postmenopausal). METHODS: More than 16,000 women were interviewed by telephone as part of the Study of Women's Health Across the Nation. They represented five ethnic/racial groups (African American, white, Chinese American, Japanese American, and Hispanic) from seven geographical sites (Boston, MA; Pittsburgh, PA; Chicago, IL; Michigan; New Jersey; and northern and southern California). RESULTS: African American women were significantly more positive in attitude. The least positive groups were the less acculturated Chinese American and Japanese American women. Menopausal status was not a consistent predictor of attitude across ethnic groups. CONCLUSIONS: In general, women's attitudes toward menopause range from neutral to positive. Ethnic groups within the United States vary slightly, but reliably, in their attitudes toward menopause and aging. Factors other than those directly associated with menopausal status seem to play a role in attitude.

Adult↗
PubMedDate not supplied

Vascular access problems in dialysis patients: pathogenesis and strategies for management.

Repetitive hemodialysis was made possible through the development of a chronic means of accessing the circulation. This was accomplished through the use of arteriovenous fistulae or grafts, using autologous veins or synthetic materials. Although the arteriovenous fistula remains the access of choice, synthetic arteriovenous grafts are used in most patients because of problems with late referral to a nephrologist and poor vasculature. This article describes the means of accessing the circulation for hemodialysis, the pathogenesis of access failure through progressive stenosis followed by thrombosis, methods of detecting access dysfunction before thrombosis, and therapeutic options. Although angiographic or surgical intervention remain the mainstays of management, medical treatments to decrease stenosis and delay thrombosis are currently under investigation.

Arteriovenous Shunt, Surgical↗