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Biomedical subjects

S J Weiss

Publications and source records attributed to S J Weiss.

At least 73 records · Page 4Linked to original sources
PubMed1997

Domestic violence in an inner-city ED.

STUDY OBJECTIVE: To determine the prevalence of domestic violence (DV) for male and female ED patients and to determine the demographics of DV. METHODS: The study design was a descriptive written survey of adults. We used the Index of Spouse Abuse (ISA), a previously validated survey tool. The study was set in an inner-city ED with approximately 75,000 patients annually, most of them indigent. Patients 18 years or older who were able to give consent were included. Patients were excluded if they had a language barrier, were a prisoner, or had never had a partner. All patients presenting during 31 randomly selected 4-hour shifts during July 1995 were considered for the study. DV was defined as either physical or nonphysical on the basis of ISA scoring. The prevalence was determined for present (in the preceding year) and past (more than 1 year ago) abuse. Four violence parameters were calculated for patients who had a partner at the time of presentation: present physical, present nonphysical, past physical, and past nonphysical. Only the "past" parameters were calculated for patients who had had a partner in the past but had no partner at the time of presentation. We used the chi2 test to determine individually significant predictors of the four parameters. Logistic-regression models were constructed to determine the significant predictors of DV. Associations among the present physical, present nonphysical, past physical, and past nonphysical abuse categories were determined with McNemar's test. RESULTS: We enrolled 516 patients, 233 men and 283 women. On the basis of ISA scoring, 14% of men and 22% of women had experienced past nonphysical violence (P=.02, men versus women), and 28% of men and 33% of women had experienced past physical violence (P=.35). Of the 157 men and 207 women with partners at the time of presentation, 11% of men and 15% of women reported present nonphysical violence (P=.20), and 20% men and 19% of women reported present physical violence (P=.71). Using logistic-regression models, we determined that women experienced significantly more past and present nonphysical violence but not physical violence than men. For all four parameters, the victim's suicidal ideation and alcohol use were independently associated with DV. The victim's family history was strongly associated with past abuse. Using McNemar's test, we found that physical and nonphysical abuse were correlated in the past and present. CONCLUSION: Using a validated scale, we found that the prevalences of physical DV for men and women are high and that they are not statistically different in this population. Using chi 2 testing, we found that women had experienced significantly more past nonphysical violence than men; using logistic regression we found that they experienced significantly more nonphysical violence (both past and present) than men. DV was frequently associated with suicidal ideation, alcohol use, and family history of violence.

Adolescent↗
PubMed1997

Research funding in the four major emergency medicine journals.

The objective of this survey was to determine the percentage of unfunded studies published in the four major emergency medicine journals and to examine the sources in funded studies. This study was a retrospective survey of all issues of the four general emergency medicine journals in 1994. Funding was categorized as public national, private, international, institutional, or unfunded. The total funding and sources were recorded for each of the four journals. Confidence intervals (CIs) were determined to compare the percent of funded versus unfunded articles. Overall, significantly more of the emergency medicine articles in the four journals were unfunded (63% unfunded [95% CI = 56.7-69.1]; 37% funded [95% CI = 30.9-43.3]). The sources of funding for each of the journals varied, with most being private (45%). In conclusion unfunded research remains a major source of emergency medicine literature in the four main emergency medicine journals.

Confidence Intervals↗
PubMed1997

Hazards associated with metalworking by artists.

Metalworking is the constructive sculptural application of various technologic processes for producing art from ferrous and nonferrous metals. Self-employed artists and their workplaces are not protected by governmental agencies. We describe the techniques involved in metalworking processes and discuss the physical trauma and medical syndromes associated with each process, as well as safety, prevention, and treatment aspects of the basic syndromes.

Air Pollutants, Occupational↗
PubMed1997

Bioimpedance cardiac output measurements in patients with presumed congestive heart failure.

OBJECTIVE: To describe preliminary ED experience with thoracic electrical bioimpedance (TEB) for evaluation of patients with complaints suggestive of congestive heart failure (CHF). METHODS: A 6-month, prospective, observational study was performed using a convenience sample of patients with signs and symptoms consistent with CHF. Patients were excluded if they had received medication prior to arrival in the ED, if they were obese, and if they had unstable vital signs. They also were excluded if they were combative, refused to sign consent, or had invasive lines that did not allow for TEB lead placement. Patients also were excluded if the study could not be completed because the patient was taken from the department for a diagnostic test, or if there were no good follow-up records available 6-12 months after the patient's visit. The patient's physician was blinded to the output of the TEB monitor. Cardiac output (CO), stroke volume (SV), end-diastolic volume (EDV), thoracic fluid index (TFI), and acceleration index (ACI) were recorded at 5-minute intervals. Results were evaluated for the time intervals 0-5 minutes, 30-35 minutes, and 60-65 minutes. RESULTS: Seven patients were included in the study. The echocardiographic diagnoses were hypertrophic cardiomyopathy (2 cases), dilated cardiomyopathy (2 cases), ischemic cardiomyopathy (1 case), right ventricular hypertrophy (1 case), and pericardial effusion (1 case). Significant changes were seen in all cardiac parameters, with variance from individual to individual. CONCLUSIONS: Significant differences in TEB variables exist between patients who appear similar on initial examination in the ED. Changes noted on TEB may help to further elucidate physiologic differences. The clinical use of TEB-based hemodynamic measurements to guide presumed CHF patient management remains speculative.

Cardiac Output↗
PubMed1996

Transmembrane-deletion mutants of the membrane-type matrix metalloproteinase-1 process progelatinase A and express intrinsic matrix-degrading activity.

Membrane-type matrix metalloproteinase-1 (MT-MMP-1) has been proposed to play a critical role in regulating the expression of tissue-invasive phenotypes in normal and neoplastic cells by directly or indirectly mediating the activation of progelatinase A. To begin characterizing MT-MMP-1 structure-function relationships, transmembrane-deletion mutants were constructed, and the processing of the zymogens as well as the enzymic activity of the mature proteinases was analyzed. We now demonstrate that pro-MT-MMP-1 mutants are efficiently processed to active proteinases following post-translational endoproteolysis immediately downstream of an Arg108-Arg-Lys-Arg basic motif by a proprotein convertase-dependent pathway. The secreted form of active MT-MMP-1 not only displays an N terminus identical with that described for the processed wild-type enzyme at Tyr112 (Strongin, A. Y., Collier, I., Bannikov, G., Marmer, B. L., Grants, G. A., and Goldberg, G. I. (1995) J. Biol. Chem. 270, 5331-5338), but also directly mediated progelatinase A activation via a two-step proteolytic cascade indistinguishable from that observed with intact cells. Furthermore, although the only function previously ascribed to MT-MMP-1 is its ability to act as a progelatinase A activator, purified transmembrane deletion mutants also expressed proteolytic activities against a wide range of extracellular matrix molecules. Given recent reports that MT-MMP-1 ectodomains may undergo intercellular transfer in vivo (Okada, A., Bellocq, J.-P., Rouyer, N., Chenard, M.-P., Rio, M.-C., Chambon, P., and Basset, P. (1995) Proc. Natl. Acad. Sci. U. S. A. 92, 2730-2734), our data suggest that soluble forms of the proteinase confer recipient cells with the ability to not only process progelatinase A, but also directly degrade extracellular matrix components.

Amino Acid Sequence↗
PubMed1996

Cocaine self-administration increased by compounding discriminative stimuli.

Presenting independently established discriminative stimuli in compound can substantially increase response rates under food and shock-avoidance schedules. To determine whether this effect extends to drug self-administration, rats were trained to press a lever to receive cocaine intravenously. A tone and a light were independently established as discriminative stimuli for cocaine self-administration, then presented in combination in a stimulus-compounding test. Compared to tone and light alone, the tone-plus-light compound stimulus increased responding approximately three-fold when cocaine was withheld during testing, and it increased drug intake approximately two-fold when cocaine was made available during testing. Compounding did not increase responding after training in a truly random control condition where tone and light were presented uncorrelated with the availability of cocaine. The results obtained with this animal model of drug abuse define conditions under which combinations of environmental stimuli might substantially increase human drug use.

Acoustic Stimulation↗
PubMed1996

Detection of stroke during cardiac operations with somatosensory evoked responses.

OBJECTIVES: The objectives of this study were to determine if monitoring of intraoperative somatosensory evoked potentials could be used to detect stroke during cardiac operations and to establish indicators of cerebral ischemia based on changes in these potentials. METHODS: Twenty-five patients undergoing cardiac operations underwent preoperative and postoperative neurologic examinations as well as intraoperative recording of somatosensory evoked potentials. Detailed analysis of the waveforms of these potentials was performed. RESULTS: Two of the 25 patients had intraoperative strokes. These patients and only these patients had changes in their somatosensory evoked potentials during the operation suggesting cerebral ischemia. The unilateral disappearance of the cortical somatosensory evoked potential waves correlated significantly with the clinical outcome of stroke (p < 0.004). Ischemic changes were detected in real time and were related to the removal of the aortic crossclamp in one patient and to the initiation of cardiopulmonary bypass in the other. CONCLUSIONS: Somatosensory evoked potentials can detect intraoperative stroke during cardiac operations. Acute, unilateral decreases in amplitude of the cortical potential are more useful than changes in latency in detecting intraoperative stroke.

Adult↗
PubMed1996

Effect of individual and work characteristics of EMTs on vital sign changes during shiftwork.

This study examines the effects of demographics, lifestyle, and work characteristics on burnout in EMTs, and then determines the interaction of various EMT risk factors on cardiovascular changes. In phase 1, EMTs voluntarily completed a demographic data sheet and the Masslach Burnout Inventory (MBI). The MBI results were broken down into subgroups of Emotional Exhaustion (EE), Depersonalization (DP), and Personal Achievement (PA); these were then compared to national averages. Subgroup analysis was performed on the basis of sex, race, marital status, years with the service, smoking, and caffeine drinking habits. In phase 2, EMTs carried logbooks for 1 month, during which they recorded preshift and postshift blood pressure and pulse. Other information recorded for each shift was the amount of caffeine and cigarettes used, the number of advanced life support (ALS) and total runs, and whether the shift worked was day or night. Per-shift average caffeine use, average number of ALS and total runs, and average cross-shift changes in MAP (deltaMAP) and P (deltaP) were calculated for each EMT. The deltaMAP and deltaP were compared for discrete variables (sex, race, training levels, smoker v nonsmoker, marital status, and shift worked) and continuous variable (age, years with the service, total runs, ALS runs, and MBI subscale scores). Continuous variables were split into two groups using the median as a separator. Differences were detected at P < .05 by confidence interval analysis. Sixty-nine EMTs enrolled in phase 1. The EMTs scored significantly lower on the PA scale than the national average (28.1 v 34.6). The low PA score was only seen in the subgroup of EMTs with the service longer than 3 years (26.1 v 30.0). Forty EMTs completed phase 2 of the study. There were no significant differences in deltaMAP detected in any subgroup. There was a significant difference in deltaP based on marital status (single, -4.5 v married, 2.6), and age (younger than 32, -4.5 v older than 32, 0.6). There were no other detected deltaP changes. In conclusion, these results showed that PA is lower in our EMTs than in the general population; EMTs with the service longer than 3 years had the lowest values. There were no significant preshift to postshift changes in blood pressure in any subgroup. There was a statistically significant preshift to postshift decrease in pulse in unmarried EMTs and in those younger than 32 years of age. These results indicate little variation in stress between EMTs and the general population and do not indicate a need for more intensive intervention programs for the management of heart rate or pulse.

Adult↗
PubMed1996

A nurse with anaphylaxis to stone fruits and latex sensitivity: potential diagnostic difficulties to consider.

BACKGROUND: There have been several recent reports describing a cross-reactivity between latex and antigens derived from a number of fruits, including those of the stone fruit family. The relationships between the allergic reactions to the antigens from these plant products are still being defined. OBJECTIVE: To characterize the IgE reactivity of a patient who had anaphylactic reactions following the ingestion of several members of the stone fruit family (ie, plum, peach, and nectarine) and had a positive clinical history for latex allergy. METHODS: The patient's serum was tested for the presence of specific IgE for latex, stone fruits, and a panel of other foods reported to be cross-reactive with latex. Prick testing was also performed with freshly prepared extracts from the implicated fruits. Finally, the immunochemical relationship between this patient's fruit and latex sensitivity was investigated by RAST inhibition. RESULTS: The patient had strongly positive skin tests to the freshly prepared fruit extracts but the in vitro food-specific IgE tests were equivocal or very low positive. In vitro latex-specific IgE tests were strongly positive. The stone fruit extracts were shown to be inhibitors of the patient's latex specific IgE by RAST inhibition. CONCLUSION: Skin testing with freshly prepared fruit extracts was more sensitive than the in vitro tests with this patient. The inhibition data support an immunochemical relationship between the patient's latex allergy and sensitivity to stone fruits.

Adult↗
PubMed1996

Combining operant-baseline-derived conditioned excitors and inhibitors from the same and different incentive classes: an investigation of appetitive-aversive interactions.

The dynamics of appetitive-aversive interaction theory were assayed in an experiment where excitors and inhibitors from the same and different incentive classes were compounded. Excitatory and inhibitory incentive properties acquired by the discriminative stimuli resulted from the reinforcement differences between components of four-component multiple training schedules, with the influence of competing peripheral responses factored into the design. Rats' barpressing was maintained in tone and in click by food or free-operant shock avoidance; extinction was programmed in click-plus-light and in the simultaneous absence of tone, click, and light. In Test 1, an excitor that occasioned operant responding and an inhibitor that occasioned response cessation were compounded. Here, compounding an inhibitor with an excitor from the same incentive class reduced responding significantly more than did compounding an inhibitor with an excitor from the other incentive class. In Test 2, the compounds consisted of elements that individually occasioned operant responding. Here, compounding stimuli that were excitors from different incentive classes appeared to create reciprocal inhibition that counteracted the additive effects produced when these stimuli were excitors from the same incentive class. Predictions from appetitive-aversive interaction theory and Weiss' two-factor model of stimulus control were confirmed within this experimental design, where all conditioning was a by-product of the behavioural contingencies programmed on the operant baselines.

Animals↗
PubMed1996

Beat-to-beat augmentation of left ventricular function by intraaortic counterpulsation.

BACKGROUND: Measuring the effects of intraaortic balloon counterpulsation (IABP) in single cardiac beats may permit an improved understanding of the physiologic mechanisms by which IABP improves the circulation. The objective of the study was to use trans- esophageal echocardiography in combination with hemodynamic measurements to test the hypothesis that IABP improves global left ventricular systolic function selectively in the IABP-augmented cardiac beats by acutely decreasing left ventricular afterload. METHODS: Twenty-seven studies in which the IABP-to-R wave trigger ratio was serially changed from 1:1, 1:2, 1:4, 0:1 (IABP off) and back to 1:1 were performed in 20 anesthetized cardiac surgical patients during IABP support. Left ventricular short-axis end-diastolic cross-sectional area, end-systolic area, mean end-systolic wall thickness, and ejection time were measured by transesophageal echocardiography at the midpapillary muscle level. Aortic pressure was measured simultaneously from the central lumen of the intraaortic balloon catheter. These measurements were used to calculate the fractional area change, end-systolic meridional wall stress, and heart rate-corrected velocity of circumferential fiber shortening. The echocardiographic and hemodynamic parameters of left ventricular preload, afterload, and systolic function immediately after balloon deflation (IABP-augmented cardiac beats) were compared to the parameters measured during nonaugmented cardiac beats to determine the beat-to-beat effects of IABP on left ventricular function. RESULTS: IABP-augmented cardiac beats had a decreased systolic arterial pressure and end-systolic meridional wall stress and increased diastolic blood pressure, fractional area change, and velocity of circumferential fiber shortening compared to nonaugmented cardiac beats. IABP did not cause significant beat-to-beat changes in heart rate, pulmonary artery diastolic pressure, or central venous pressure. The improvement in left ventricular systolic function associated with IABP-augmented cardiac beats correlated with the decrease in end-systolic meridional wall stress for that cardiac beat. CONCLUSIONS: Beat-to-beat echocardiographic and hemodynamic measurements performed in anesthetized cardiac surgical patients during IABP support demonstrated improved left ventricular systolic function and decreased left ventricular systolic wall stress in the cardiac beats immediately after balloon deflation. The relationship between left ventricular systolic function and left ventricular systolic wall stress during IABP support suggests that afterload reduction was an important mechanism by which IABP instantaneously improved circulatory function in anesthetized cardiac surgical patients.

Adult↗
PubMed1996

Human immunodeficiency virus infection and multilocular thymic cysts.

PURPOSE: Pathologic changes of the thymus, often seen in children with the human immunodeficiency virus (HIV), reflect direct invasion by the virus, followed by involution of the gland. A previously unknown form of thymic response to HIV infection, that of a multilocular thymic cyst, is reported. MATERIALS AND METHODS: Findings were examined in three HIV-positive patients, two children and one adult first seen with large thymic masses. RESULTS: All three had large, septate low-attenuation areas at computed tomography consistent with multilocular thymic cysts. The cystic nature of the lesions was confirmed with magnetic resonance imaging in two. Histopathologic examination, performed in two instances, helped establish the diagnosis. All patients remained in clinically stable condition. They all had parotid gland enlargement and lymphocytic interstitial pneumonia. CONCLUSION: Multilocular thymic cysts are probably another manifestation of the diffuse infiltrative lymphocytosis syndrome, usually associated with a milder course of acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1995

Furin-dependent intracellular activation of the human stromelysin-3 zymogen.

Human stromelysin-3, a new member of the matrix metalloproteinase family, is expressed in tissues undergoing the active remodelling associated with embryonic development, wound healing and tumour invasion. But like all other members of the matrix metalloproteinase gene family, stromelysin-3 is synthesized as an inactive precursor that must be processed to its mature form in order to express enzymic activity. Here we identify stromelysin-3 as the first matrix metalloproteinase to be discovered that can be processed directly to its enzymically active form by an obligate intracellular proteolytic event that occurs within the constitutive secretory pathway. Intracellular activation is regulated by an unusual 10-amino-acid insert sandwiched between the pro- and catalytic-domains of stromelysin-3, which is encrypted with an Arg-X-Arg-X-Lys-Arg recognition motif for the Golgi-associated proteinase, furin, a mammalian homologue of the yeast Kex2 pheromone convertase. A furin-stromelysin-3 processing axis not only differentiates the regulation of this enzyme from all previously characterized matrix metalloproteinases, but also identifies pro-protein convertases as potential targets for therapeutic intervention in matrix-destructive disease states.

Amino Acid Sequence↗
PubMed1995

Pericellular mobilization of the tissue-destructive cysteine proteinases, cathepsins B, L, and S, by human monocyte-derived macrophages.

Human macrophages are believed to damage host tissues in chronic inflammatory disease states, but these cells have been reported to express only modest degradative activity in vitro. However, while examining the ability of human monocytes to degrade the extracellular matrix component elastin, we identified culture conditions under which the cells matured into a macrophage population that displayed a degradative phenotype hundreds of times more destructive than that previously ascribed to any other cell population. The monocyte-derived macrophages synthesized elastinolytic matrix metalloproteinases (i.e., gelatinase B and matrilysin) as well as cysteine proteinases (i.e., cathepsins B, L, and S), but only the cathepsins were detected in the extracellular milieu as fully processed, mature enzymes by either vital fluorescence or active-site labeling. Consistent with these observations, macrophage-mediated elastinolytic activity was not affected by matrix metalloproteinase inhibitors but could be almost completely abrogated by inhibiting cathepsins L and S. These data demonstrate that human macrophages mobilize cysteine proteinases to arm themselves with a powerful effector mechanism that can participate in the pathophysiologic remodeling of the extracellular matrix.

Binding Sites↗