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Biomedical subjects

S M Roth

Publications and source records attributed to S M Roth.

31 records · Page 2Linked to original sources

Duplex imaging of lower extremity bypasses, angioplasties, and stents.

Duplex scan surveillance after lower extremity bypass and endovascular interventions can have a favorable impact on outcome. Its application during an arterial intervention to exclude technical or hemodynamic abnormalities and as part of a postoperative surveillance program to detect stenosis has been shown to improve patency. Results of duplex imaging can identify the arterial reconstruction at high risk of failure/thrombosis, which requires more intensive surveillance. Based on stenosis severity and anatomy, duplex scanning can suggest which repair technique (open surgery vs percutaneous balloon angioplasty [PTA]) is more appropriate. The use of duplex imaging during PTA of graft or peripheral artery stenoses (duplex-monitored balloon angioplasty) is recommended to verify normalization of velocity spectra, because this end point is associated with improved stenosis-free patency. A duplex surveillance program combined with correction of progressively stenotic lesions is recommended after lower limb bypass and PTA.

Algorithms↗

Blunt injury of the abdominal aorta: a review.

Injury to the abdominal aorta after blunt trauma occurs much less frequently than injury to the thoracic aorta. Although presentations vary, common themes continue to emerge with each patient. Within a 6-month period, our trauma unit diagnosed and treated two cases of blunt abdominal aortic trauma. Both patients were restrained passengers in motor vehicle crashes with resultant abdominal aortic injuries and demonstrated some of the most common associated injuries. Our two cases bring the number found in the literature to 62 and demonstrate the need for rapid recognition and treatment of this potentially lethal injury. This article is a comprehensive review of the management of abdominal aortic injury from blunt trauma.

Accidents, Traffic↗

Radiology CME on the Web using secure document transfer and internationally distributed image servers.

We describe the implementation of a World Wide Web-based Continuing Medical Educational (CME) program in Diagnostic Radiology which allows accumulation of Category I credit. The program implements an unknown case presentation format which includes multiple choice questions, didactic information, and literature references with links to abstracts. Physician participation is anticipated to occur in brief sessions during which the program automatically tracks CME credit accumulation. To allow an interactive presentation, HTML electronic form documents are created "on the fly" by a Common Gateway Interface (CGI) application interfacing with several relational databases. The system is scalable with bandwidth intensive image transfers distributed over multiple internationally distributed image servers. For CME participants, the system utilizes documents encryption to ensure confidential physician interactions.

Computer Communication Networks↗

A ten-year follow-up on a prospective, randomized trial of postoperative corticosteroids after trabeculectomy.

PURPOSE: Patients prospectively enrolled in a clinical trial to evaluate the effect of corticosteroid use after guarded filtration procedure (trabeculectomy) were re-evaluated after 10 years to determine whether (1) there were differences in intraocular pressure (IOP) level and stability of glaucoma between treated and nontreated eyes, (2) surgery had altered the clinical course of the patients, and (3) there was any relation between level of IOP and glaucoma control. METHODS: Forty-six eyes of 35 patients were evaluated individually. Stabilization/ progression of glaucoma was established based on IOP, clinical evaluation of visual fields, and stereoscopic analysis of disc using ophthalmoscopy and photography. RESULTS: The nonsteroid-treated eyes underwent more additional glaucoma surgeries, were treated with more glaucoma medicines, and had higher IOPs. Glaucoma was stabilized in 82.8% of the steroid-treated eyes and 67% of the nonsteroid-treated eyes. There was a direct correlation between level of IOP and stabilization of optic nerve and visual field in both groups. CONCLUSION: The use of corticosteroids after guarded filtration procedure was correlated with better glaucoma control. Patients with lower IOPs were more likely to be stabilized than those with higher pressures.

Administration, Topical↗

A method for interactive medical instruction utilizing the World Wide Web.

We describe the implementation of interactive medical teaching programs in radiology and histology which utilize the Internet's World Wide Web (WWW). The WWW standard hypertext interface allows for simple navigation between related documents but does not provide a method for student tracking or question queries. Electronic forms, a recent feature of the WWW, provide the means to present question documents to remote clients and track student performance. A feature of our approach is dynamic creation of HTML documents based upon interaction with database applications. The approach allows multiple simultaneous, yet asynchronous interactions by geographically dispersed students upon the same instructional database and is scalable, providing the capability for multiple image/document servers. The security of the database is assured given that it is not accessible through the Internet.

Computer Communication Networks↗

Characterization of the secondary structure of calmodulin in complex with a calmodulin-binding domain peptide.

The interaction between calcium-saturated chicken calmodulin and a peptide corresponding to the calmodulin-binding domain of the chicken smooth muscle myosin light chain kinase has been studied by multinuclear and multidimensional nuclear magnetic resonance methods. Extensive 1H and 15N resonance assignments of calmodulin in the complex have been obtained from the analysis of two- and three-dimensional nuclear magnetic resonance spectra. The assignment of calmodulin in the complex was facilitated by the use of selective labeling of the protein with alpha-15N-labeled valine, alanine, lysine, leucine, and glycine. These provided reference points during the main-chain-directed analysis of three-dimensional spectra of complexes prepared with uniformly 15N-labeled calmodulin. The pattern of nuclear Overhauser effects (NOE) seen among main-chain amide NH, C alpha H, and C beta H hydrogens indicates that the secondary structure of the globular domains of calmodulin in the complex closely corresponds to that observed in the calcium-saturated state of the protein in the absence of bound peptide. However, the backbone conformation of residues 76-84 adopts an extended chain conformation upon binding of the peptide in contrast to its helical conformation in the absence of peptide. A sufficient number of NOEs between the globular domains of calmodulin and the bound peptide have been found to indicate that the N- and C-terminal regions of the peptide interact with the C- and N-terminal domains of calmodulin, respectively. The significance of these results are discussed in terms of recently proposed models for the structure of calmodulin-peptide complexes.

Amino Acid Sequence↗

Structure of the smooth muscle myosin light-chain kinase calmodulin-binding domain peptide bound to calmodulin.

The interaction between the peptide corresponding to the calmodulin-binding domain of the smooth muscle myosin light-chain kinase and (Ca2+)4-calmodulin has been studied by multinuclear and multidimensional nuclear magnetic resonance methods. The study was facilitated by the use of 15N-labeled peptide in conjunction with 15N-edited and 15N-correlated 1H spectroscopy. The peptide forms a 1:1 complex with calcium-saturated calmodulin which is in slow exchange with free peptide. The 1H and 15N resonances of the bound have been assigned. An extensive set of structural constraints for the bound peptide has been assembled from the analysis of nuclear Overhauser effects and three-bond coupling constants. The backbone conformation of the bound peptide has been determined using these constraints by use of distance geometry and related computational methods. The backbone conformation of the peptide has been determined to high precision and is generally indicative of helical secondary structure. Nonhelical backbone conformations are seen in the middle and at the C-terminal end of the bound peptide. These studies provide the first direct confirmation of the amphiphilic helix model for the structure of peptides bound to calcium-saturated calmodulin.

Amino Acid Sequence↗

Avoidance behaviour: a predictor of the efficacy of pharmacotherapy in panic disorder?

The impact of the avoidance behaviour on the psychopharmacological treatment of panic disorder was explored in the Cross National Collaborative Panic Study (n = 1134 patients); in this double blind randomized trial alprazolam, imipramine and placebo were compared during an 8-week treatment period. Patients with extensive avoidance behaviour (agoraphobia) had the most profit from the active drugs. Counter expectancy these specific drug effects were most pronounced in avoidance behaviour. Active drugs (in particular imipramine) were especially more effective than placebo if the patients presented with associated avoidance behaviour. The results suggest that agoraphobia defines more a particular type of anxiety disorder overlapping with panic disorder than merely a severe state of panic disorder.

Adult↗

The effects of postoperative corticosteroids on trabeculectomy and the clinical course of glaucoma: five-year follow-up study.

A randomized, prospective study on 68 eyes of 54 patients with progressive, uncontrolled, noninflammatory open-angle glaucoma showed that eyes that received topical prednisolone 1% had a lower intraocular pressure (IOP) 18 months following trabeculectomy than the eyes that received no prednisolone. The addition of systemic prednisone had no definite further effect. In the present study, we reevealuated 58 eyes of 45 of these patients 5 years after the time of initial surgery. The number of cases lost to follow up was similar in the steroid and the nonsteroid-treated groups. Mean IOP of the steroid-treated patients was 14.5 +/- 1.8 mm Hg, and of the nonsteroid-treated patients, 19.3 +/- 2.1 mm Hg. Visual field, optic disc, and IOP were stabilized in 94% of the steroid-treated cases and in 43% of the nonsteroid-treated cases. Thus, postoperative steroids significantly increased the success rate of trabeculectomy in these eyes, and the eyes with lower IOPs had a significantly better prognosis than those with higher IOPs.

Adult↗

Thymosin-like peptides as potential immunostimulants. Synthesis via the polymeric-reagent method.

This paper reports our attempt at designing new immunostimulating peptides which are chemically related to the bioactive peptides thymosin alpha 1 and thymopentin. Three peptides were synthesized, Asp-Leu-Lys-Glu-Arg-Lys-Asp-Val-Tyr (3), Arg-Lys-Asp-Val-Tyr-Glu-Glu-Ala-Glu-Asn (2), and Asp-Leu-Lys-Glu-Arg-Lys-Asp-Val-Tyr-Glu-Glu-Ala-Glu-Asn (1), each of which contains the thymopentin sequence and portions of the bioactive sequence of thymosin alpha 1. Peptides 1-3 were assembled from selected blocked fragments that were synthesized by the polymeric-reagent method, using PHBT (polystyrene-bound 1-hydroxybenzotriazole) as the activating polymer. The ability of peptides 1-3 to enhance the activation (RNA synthesis) and proliferation (DNA synthesis) of human T lymphocytes was determined. In comparison to thymosin alpha 1, thymosin alpha 1 (15-28), and thymopentin, peptides 1-3 did not show significant enhancement of these processes.

Amino Acid Sequence↗

Anxiety disorders and the use and abuse of drugs.

Substance abuse continues to be a growing problem--both in the United States and worldwide. Moderate alcohol consumption reduces anxiety, but alcohol abuse actually increases anxiety and impairs judgment and performance. Research data indicate that phobic anxiety is more common than general anxiety as a prelude to alcohol dependence. Benzodiazepines are widely used throughout the world in the treatment of anxiety disorders. Patients who take benzodiazepines for clinical anxiety rarely exceed the prescribed dosage: benzodiazepine abuse is more likely to occur in those who abuse other drugs. For most people suffering from anxiety disorders, low doses of benzodiazepines for short periods are usually sufficient. When discontinuing patients from benzodiazepines, it is essential for physicians to monitor patients closely and to provide emotional support and counselling about the withdrawal process and potential clinical syndromes associated with it. The need for retaining the option of giving benzodiazepines in the management of anxiety disorders arises from the chronic nature of a high proportion of the anxiety disorders. More research is needed to examine the effects of pharmacologic, behavioral, psychotherapeutic, and combinations of these treatments in patients with chronic anxiety and phobic disorders.

Anxiety Disorders↗

Psychosensorial and related phenomena in panic disorder and in temporal lobe epilepsy.

Since Cullen coined the term "neurosis" in the 18th century, medical investigators have searched the neural substrates of conditions we now classify as anxiety disorders. Harper and Roth in 1962 hypothesized that the temporal lobes might represent one such substrate for phobic-anxious patients with depersonalization-derealization (DD); the association between the presumed temporal lobe feature and phobic anxiety was so compelling that Roth (in 1959) described the condition as "phobic-anxiety-depersonalization" syndrome. Introduced into our current nosology as panic disorder-agoraphobia (PDA), this seemingly neuropsychiatric condition is nonetheless distinct from complex partial epilepsy (CPE), from which it is conventionally differentiated through clinical and anamnestic evaluation. Yet increasingly there are clinical-and laboratory-hints of certain overlap between manifestations of the two disorders, hitherto based largely on evaluation of psychosensorial phenomena in PDA or affective phenomena in CPE. We located only one systematic study that monitored 24-hour electroencephalogram (EEG) abnormalities in PDA. Finally, recent epidemiologic data suggest a significantly greater than chance association between PDA and a history of seizures. To further explore these intriguing links, the present study directly compared a group of 91 PDA outpatients with a group of 41 CPE outpatients with respect to DD and other psychosensorial symptoms. The broad similarities discovered between psychosensorial and related phenomena provide further support for the hypothesis that there may be a common neurophysiological substrate linking CPE phenomena with PDA.

Adolescent↗