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Biomedical subjects

M R Shah

Publications and source records attributed to M R Shah.

At least 19 recordsLinked to original sources
PubMed2001

Prognostic usefulness of the six-minute walk in patients with advanced congestive heart failure secondary to ischemic or nonischemic cardiomyopathy.

Clinicians have relied on history and results from physical examinations to guide treatment of patients with advanced congestive heart failure, but these results may not reflect disease severity or hemodynamic status. We assessed how the distance walked in 6 minutes relates to clinical outcomes and symptoms of such patients. We compared the rates of death, hospitalization, and their composite at 1 year by the distance walked in 6 minutes at baseline and at 1 month, and by the change in distance between baseline and 1 month in 440 patients enrolled in a randomized trial. We also assessed the relations of baseline distance walked to symptom score and New York Heart Association class. The median distance increased from 218 m at baseline to 280 m at 1 month. Of 365 patients able to perform the baseline walk, 121 (33%) died and 217 (60%) were hospitalized compared with 46 (61%) and 34 (45%) of 75 patients unable to walk at baseline. Baseline distance significantly predicted mortality (hazard ratio 0.58/100-m increase, 95% confidence interval 0.50 to 0.68, p <0.001), even after adjustment. Baseline distance also significantly predicted hospitalization and the composite end point, as did the 1-month distance walked. The change in distance walked from baseline to 1 month did not predict any end point. Baseline distance correlated only moderately with symptom score (r = -0.385, p <0.001) and New York Heart Association class (r = -0.468, p <0.001). Distance walked during 6 minutes independently and strongly predicts mortality and hospitalization in patients with advanced congestive heart failure. This may be a simple, noninvasive, objective way to risk-stratify these patients and standardize their treatment.

Aged↗
PubMed2001

Gene transfer of heat-shock protein 70 reduces infarct size in vivo after ischemia/reperfusion in the rabbit heart.

BACKGROUND: Heat-shock protein 70 (HSP 70) plays a role in myocardial protection. No studies are available, however, to show that direct gene transfer of HSP 70 reduces myocardial infarction in vivo. METHODS AND RESULTS: Rabbit hearts were injected with vehicle or Ad.HSP70 at 3 sites (1.5x10(9) pfu, 50 microL/site) in the left ventricle (LV). Four days later, hearts were removed, and expression of inducible (HSP 70) and constitutive (HSC 70) proteins was measured in the LV and right ventricle (RV). Subsets of 5 to 7 animals in the vehicle-, Ad.lacZ-, and Ad.HSP70-treated groups were subjected to 30 minutes of ischemia and 3 hours of reperfusion. Infarct size was measured by tetrazolium staining. Increased expression of HSP 70 was observed in LV injected with Ad.HSP70 compared with vehicle-treated hearts. HSP 70 was undetectable in RV, the noninjected region of the heart. The expression of HSC 70 remained unchanged in hearts treated with vehicle or Ad.HSP70. Infarct size (% risk area) decreased to 24.5+/-2.8 in Ad.HSP70-injected hearts compared with 41.9+/-2.8 and 42.7+/-2.5 in the vehicle- and Ad.LacZ-treated hearts (P<0.01). The infarct size was not different between the vehicle- and Ad.LacZ-treated hearts (P>0.05). The risk areas (% of LV) were not different among the 3 groups, ie, 50.1+/-5.2, 47.7+/-3.5, and 53.3+/-2.9 in vehicle-, Ad.lacZ-, and Ad.HSP70-treated groups (P>0.05). CONCLUSIONS: Direct gene delivery of HSP 70 in vivo reduces the severity of ischemic injury in the heart.

Adenoviridae↗
PubMed2001

Hemodynamic profiles of advanced heart failure: association with clinical characteristics and long-term outcomes.

BACKGROUND: Classifying patients with advanced congestive heart failure (CHF) by baseline measures of congestion and perfusion has been used to estimate hemodynamic status and to select and titrate therapy. We describe clinical characteristics of 4 hemodynamic profiles-wet/cold, wet/warm, dry/cold, and dry/warm-in patients with advanced CHF and assess relations between symptoms, physical signs, and outcomes with each profile. METHODS AND RESULTS: We retrospectively assessed baseline symptoms, physical-examination variables, and 1-year outcomes of 440 patients in a randomized trial. With univariable and multivariable logistic regression, we examined relations of physical-examination variables to hemodynamic profiles. We also assessed the rates of death and death or readmission by profile. Severity of CHF symptoms did not predict the wet-versus-dry profile or cold-versus-warm status, despite significant differences in hemodynamics among groups. Of the physical-examination variables, only a lower proportional pulse pressure was a significant multivariable predictor of the wet category. Among wet patients (n = 348), this same variable was the only significant multivariable predictor of the cold category. For dry patients (n = 92), the cold category was predicted in multivariable analysis by supine heart rate and hepatomegaly. Survival was similar among profiles: wet/cold, 54.2% (n = 91); wet/warm, 58.3% (n = 105); dry/cold, 78.9% (n = 15); and dry/warm, 67.1%, P =.13 (n = 49). Event-free survival also was similar among profiles: wet/cold, 22.0% (n = 37); wet/warm, 29.4% (n = 53); dry/cold, 42.1% (n = 8); and dry/warm, 31.5%, P =.44 (n = 23). CONCLUSIONS: The patient's history and physical examination alone may lead to inaccurate estimation of hemodynamic status and thus suboptimal management for patients with advanced CHF.

Aged↗
PubMed2001

Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE): design and rationale.

BACKGROUND: There is little information about how to adjust pharmacologic agents in the treatment of patients with advanced congestive heart failure (CHF). Some studies have suggested that use of pulmonary artery catheterization to guide reductions in filling pressures may improve outcomes for patients with heart failure who are hospitalized with evidence of elevated filling pressures. However, there is no consensus regarding the true utility of this strategy. A randomized clinical trial is needed to test the safety, efficacy, and treatment benefit of pulmonary artery catheterization in patients with advanced CHF. STUDY DESIGN: The Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial is a multicenter, randomized trial designed to test the long-term safety and efficacy of treatment guided by hemodynamic monitoring and clinical assessment versus that guided by clinical assessment alone in patients hospitalized with New York Heart Association class IV CHF. Five hundred patients will be randomly assigned to receive either medical therapy guided by a combination of clinical assessment and hemodynamic monitoring (PAC arm) or medical therapy guided by clinical assessment alone (CLIN arm). The primary end point of ESCAPE will be the number of days that patients are hospitalized or die during the 6-month period after randomization. Secondary end points will include changes in mitral regurgitation, peak oxygen consumption, and natriuretic peptide levels. Other secondary end points will be pulmonary artery catheter-associated complications, resource utilization, quality of life measures, and patient preferences regarding survival. IMPLICATIONS: The primary goal of ESCAPE will be to provide information about the utility of the pulmonary artery catheter in patients with advanced heart failure, independent of various treatment approaches used by individual physicians. In addition, this study will define current outcomes for this severely compromised population.

Catheterization, Swan-Ganz↗
PubMed2001

Hemodynamics as surrogate end points for survival in advanced heart failure: an analysis from FIRST.

BACKGROUND: Hemodynamics often are used as surrogate end points in phase II trials of acute heart failure (HF). We reviewed the Flolan International Randomized Survival Trial (FIRST) database to identify the hemodynamic variables that best predict survival in patients with advanced HF receiving epoprostenol therapy and to determine whether hemodynamics could predict the overall effect of a drug. METHODS: The trial enrolled 471 patients with class IIIb/IV HF and ejection fraction or=3 months, all of whom underwent screening pulmonary artery catheter insertion. Patients were randomly assigned to receive either epoprostenol (n = 201) or placebo (n = 235); epoprostenol therapy was guided by pulmonary artery catheter measures, and standard treatment was guided by clinical findings. Multivariable modeling was used to identify and quantify the demographic, clinical, and hemodynamic variables most associated with 1-year survival. RESULTS: In multivariable modeling, HF class, decreased pulmonary capillary wedge pressure (PCWP), and age best predicted 1-year survival. After adjustment for age and HF class, decreased PCWP still significantly predicted survival (hazard ratio, 0.96 for every 1-mm Hg decrease; 95% confidence interval, 0.94 to 0.99; P = .003). Survival was significantly higher with decreases in PCWP >or=9 versus <9 mm Hg, even after adjustment for age and HF class. Survival of patients in the PCWP >or=9 group was comparable with, and that of the PCWP <9 group was significantly higher than, survival of patients in the control group (hazard ratio, 1.44; 95% confidence interval, 1.05 to 1.99; P = .024). CONCLUSIONS: The reduction in PCWP was the hemodynamic measure most predictive of survival in patients with advanced HF. However, patients with a >or=9-mm Hg decrease had no better survival than patients in the control group, who had limited changes in hemodynamics. Thus, improvement in hemodynamics may not predict the overall effect of a drug.

Aged↗
PubMed2001

Outcome after hip fracture in individuals ninety years of age and older.

OBJECTIVE: To assess outcome after hip fracture in patients ninety years of age and older, as compared with a population of the same age and sex in the United States and younger patients with hip fractures. DESIGN: Prospective, consecutive. SETTING: University teaching hospital. METHODS: Eight hundred fifty community-dwelling elderly people who sustained an operatively treated hip fracture were prospectively followed up. MAIN OUTCOME MEASUREMENTS: The outcomes examined in this study were the patients' in-hospital mortality and postoperative complication rates, hospital length of stay, discharge status, mortality rate, place of residence, ambulatory ability, and independence in basic and instrumental activities of daily living twelve months after surgery. RESULTS AND CONCLUSIONS: The mean patient age was 79.7 years (range 65 to 105 years). Seventy-six (8.9 percent) patients were ninety years of age and older. Patients who were ninety years of age and older had significantly longer mean hospital lengths of stay than younger individuals (p = 0.01). People ninety years of age and older were more likely to die during the hospital stay (p = 0.001) and within one year of surgery (p = 0.001). Patients who were ninety years of age and older were more likely to have a decrease in their basic activities of daily living status (p = 0.03) and ambulation level (p = 0.01). Younger individuals had a higher standard mortality ratio (1.48) than did patients who were ninety years of age and older (1.24). Being ninety years of age and older was not predictive of having a postoperative complication, of being placed in a skilled nursing facility at discharge or at one-year follow-up, or recovering of prefracture independence in instrumental activities of daily living.

Activities of Daily Living↗
PubMed1998

RANTES expression and contribution to monocyte chemotaxis in arthritis.

Rheumatoid arthritis (RA) is characterized by recruitment of leukocytes from the vasculature into inflamed synovial tissue (ST) and synovial fluid (SF), which depends, in part, upon the continued maintenance of chemotactic stimuli. RANTES is a potent chemoattractant for leukocytes including monocytes and CD45RO+ memory T lymphocytes. The aim of this study was to determine the production, the source, and the function of antigenic RANTES in arthritis. We detected antigenic RANTES in SFs from RA and OA patients (100 +/- 22.7 and 72 +/- 30.7 pg/ml, respectively). CM from RA ST fibroblasts stimulated with interleukin-1beta or tumor necrosis factor-alpha contained significantly more antigenic RANTES than unstimulated CM (452 +/- 181.6 and 581 +/- 200.2 pg/ml, respectively, versus 12 +/- 4.4 pg/ml, P < 0.05). PHA-stimulated RA SF mononuclear cells secreted 5- to 15-fold more antigenic RANTES than did nonstimulated mononuclear cells, while LPS induced secretion up to 4-fold. We immunolocalized antigenic RANTES to sublining macrophages (28 +/- 3.7 and 8 +/- 2.0% immunopositive cells), perivascular macrophages (56 +/- 6.9 and 19 +/- 3.4%), and synovial lining cells (37 +/- 5.8 and 60 +/- 10.4%) in RA and OA tissue, respectively. Anti-RANTES neutralized 20.2 +/- 1.3% of the RA SF chemotactic activity for normal peripheral blood monocytes (P < 0.05). These results demonstrate antigenic RANTES in RA and OA ST and SF and identify RANTES as a chemoattractant for monocytes in the RA joint.

Antigens↗
PubMed1998

A study of printed spiral coils for neuroprosthetic transcranial telemetry applications.

We have explored the use of printed spiral coils (PSC's) for neuroprosthetic transcranial telemetry applications. We fabricated two-dimensional PSC's on a thin (25 microns) polyimide substrate using copper (35 microns) as a conducting material. All the coils had a fixed inner diameter of 1.0 cm. We fabricated two sets of coils. One set of coils consisted of 2- to 5-turn circular and square spiral coils and had different trace widths (W), different spacings (S) between adjacent traces, and different outer diameters. The other set of coils consisted of 5-turn circular spiral coils and had fixed inner and outer diameters but different W to S ratios. We measured loss resistances (Rs and Rp) and quality factors (Q) of these coils at different resonating frequencies in the range of 5-40 MHz. Over this frequency range, we observed that for fixed inner and outer diameters, the coil with the largest W achieved the lowest Rs and the highest Rp and Q. These electrical properties and the fact that these coils can conform to the complex convoluted cortical surface suggest that a PSC [15] can provide a viable alternative to a conventional wire-wound coil for neuroprosthetic transcranial telemetry applications.

Biocompatible Materials↗
PubMed1997

Low-level production of interleukin-13 in synovial fluid and tissue from patients with arthritis.

Rheumatoid arthritis (RA) is a chronic, aggressive disease characterized by inflammatory cells in the synovial tissue (ST) and synovial fluid (SF). Interleukin (IL)-13 inhibits the production of proinflammatory cytokines, chemokines, and hematopoietic growth factors by activated human monocytes. The aim of this study was to determine the production of IL-13 in various forms of arthritis. The presence of IL-13 in RA was found to be low, in that 18 of 26 RA SF samples and 10 of 14 RA peripheral blood (PB) samples had nondetectable levels (</=12 pg/ml). Similar low levels were found in SF and PB from patients with osteoarthritis (OA) and other arthritides. In contrast, RANTES, IL-8, monocyte chemotactic protein-1, and soluble P-selectin were found at levels of 13-, 120-, 1200-, and 2000-fold excess of IL-13, respectively. Mononuclear cells isolated from RA SFs did not produce significant levels of IL-13 in culture (</=12 pg/ml) but were able to do so when stimulated with phytohemagglutinin. Likewise, tissue explants from RA synovium cultured for 24 or 48 hr with or without serum did not produce appreciable quantities of IL-13 (</=12 pg/ml). Immunohistochemical data were in accordance with this result in that antigenic IL-13 was not detected on the majority of RA, OA, and normal (NL) ST cells. These results demonstrate a paucity of IL-13 within the joints of RA, OA, NL, and other arthritic patients by comparison with levels of other cytokines.

Arthritis↗
PubMed1997

Monophosphoryl lipid A protects adult rat cardiac myocytes with induction of the 72-kD heat shock protein: a cellular model of pharmacologic preconditioning.

We examined the in vitro preconditioning effect of non-toxic derivative of endotoxin, monophosphoryl lipid A (MLA) in adult rat cardiac myocytes. Cultured 5-7-day-old myocytes were preconditioned for 4 h by treatment with 200 ng/ml MLA. Twenty h later, cells were subjected to simulated ischemia by incubation in 0.75 mm sodium hydrosulfite, 12 mM KCl, 20 mM dl-lactic acid and 10 mM 2-deoxy-D-glucose (pH 6.5) for 2 h. MLA caused a significant reduction in the levels of LDH from 286+/-8 units/l in controls to 165+/-5 units/l (mean+/-s.e.m.; P<0.0001). Similarly, CK significantly decreased from 104+/-3.1 in controls to 85+/-1.4 U/l (P<0.001). Western blot analysis indicated a significant accumulation of 72 kD heat shock protein in MLA treated as compared to control cells. No changes in 27, 32, and 90 kD heat shock proteins were discernible in the MLA treated group. These data suggest a significant "anti-ischemic" effect of MLA in myocytes that is accompanied by induction of 72 kD heat shock protein.

Animals↗
PubMed1996

Hepatocyte growth factor. A cytokine mediating endothelial migration in inflammatory arthritis.

OBJECTIVE: Angiogenesis is an integral component of the vasculoproliferative phase of rheumatoid arthritis (RA). Recently, a heparin-binding cytokine termed hepatocyte growth factor (HGF), or scatter factor (due to its ability to disperse cohesive epithelial colonies), was described. We conducted this study to investigate the hypothesis that this cytokine was present in the milieu of the inflamed joint, and that it contributed to the chemotaxis of endothelial cells in the synovial tissue. METHODS: We examined synovial fluid, synovial tissue, and peripheral blood from 91 patients with RA and other arthritides. We used 83 total samples in an enzyme-linked immunosorbent assay to quantitate the HGF in synovial fluids and peripheral blood. To determine whether the HGF was biologically active, an epithelial scatter factor assay was performed. Immunohistochemical analysis was used to determine localization in synovial tissues. To define a function for synovial HGF, we preincubated rheumatoid synovial fluids with neutralizing anti-HGF and measured the ability of these synovial fluids to induce endothelial chemotaxis. RESULTS: Synovial fluid from patients with RA contained a mean +/- SEM HGF concentration of 2.0 +/- 0.3 ng/ml, while synovial fluid from patients with other arthritides (including inflammatory arthritis) contained 2.4 +/- 0.7 ng/ml HGF. Osteoarthritis (OA) patient samples contained the smallest quantities of synovial fluid HGF at 0.9 +/- 0.1 ng/ml. RA synovial fluid contained significantly more HGF than did RA peripheral blood (1.1 +/- 0.2 ng/ml) (P < 0.05). Rheumatoid synovial fluids induced more scattering of cells than did OA synovial fluids, suggesting a role for this cytokine in rheumatoid joint destruction. Interleukin-1 beta induced expression of rheumatoid synovial tissue fibroblast antigenic HGF and scatter factor activity. Immunohistochemically, HGF, as well as the HGF receptor (the met gene product), localized to significantly more rheumatoid synovial tissue lining cells than normal lining cells (P < 0.05). Both HGF and its receptor immunolocalized to subsynovial macrophages as well. Levels of synovial tissue immunoreactive HGF correlated positively with the number of synovial tissue blood vessels. Anti-HGF neutralized a mean of 24% of the chemotactic activity for endothelial cells found in 10 rheumatoid synovial fluid samples. CONCLUSION: These results indicate that synovial HGF may contribute to the vasculoproliferative phase of inflammatory arthritides such as RA, by inducing HGF-mediated synovial neovascularization. These findings point to a newly described role for HGF in the fibroproliferative phase of RA-associated synovitis.

Arthritis, Rheumatoid↗
PubMed1996

Soluble forms of P-selectin and intercellular adhesion molecule-3 in synovial fluids.

A number of adhesion molecules have been identified in synovial tissues of patients with rheumatoid arthritis (RA). Some of them are upregulated and may play an important role in the inflammatory processes of the diseased joint. In addition to synovial tissue cell surface expression, synovial fluids contain soluble forms of many adhesion molecules, such as intercellular adhesion molecule-1, E-selectin (sE-selectin), and L-selectin. In this study, we investigated the expression of soluble P-selectin (sP-selectin) and intercellular adhesion molecule-3 (sICAM-3) in synovial fluids from patients with RA, osteoarthritis (OA), and other forms of arthritis. sP-selectin and sICAM-3 levels in RA synovial fluids were significantly increased compared to those in OA. The levels of sP-selectin++ in synovial fluids correlated with sICAM-3 and sE-selectin in synovial fluids. The levels of sICAM-3 in synovial fluids correlated with synovial fluid leukocyte counts and erythrocyte sedimentation rate. In vitro, synovial fluid mononuclear cells produced sICAM-3 spontaneously. Elevated levels of sP-selectin and sICAM-3 in RA synovial fluids compared to OA may indicate inflammatory interactions between endothelial cells, leukocytes, and other synovial cells in the diseased joint.

Antigens, CD↗
PubMed1995

Growth-related gene product alpha. A chemotactic cytokine for neutrophils in rheumatoid arthritis.

Leukocyte recruitment is critical in the inflammation seen in rheumatoid arthritis (RA). To determine whether the chemokine growth-related gene product alpha (gro alpha) plays a role in this process, we examined synovial tissue (ST), synovial fluid (SF), and plasma samples from 102 patients with arthritis. RA SF contained more antigenic gro alpha (mean 5.3 +/- 1.9 ng/ml) than did SFs from either osteoarthritis (OA) or other forms of arthritis (mean 0.1 ng/ml) (p < 0.05). RA plasma contained more gro alpha (mean 4.3 +/- 1.8 ng/ml) than normal plasma (mean 0.1 ng/ml) (p < 0.05). RA ST fibroblasts (1.2 x 10(5)/cells/mI RPMI 1640/24 h) produced antigenic gro alpha (mean 0.2 +/- 0.1 ng/ml), and this production was increased significantly upon incubation with TNF-alpha (mean 1.3 +/- 0.3 ng/ml) or IL-1 beta (mean 2.3 +/- 0.6 ng/ml) (p < 0.05). Cells from RA SF also produced gro alpha: neutrophils (PMNs) (10(7) cells/mI/24 h) produced 3.7 +/- 0.7 ng/ml. RA SF mononuclear cells produced gro alpha, particularly upon incubation with LPS or PHA. Immunoreactive ST gro alpha was found in greater numbers of RA compared with either OA or normal lining cells, as well as in RA compared with OA subsynovial macrophages (p < 0.05). IL-8 accounted for a mean of 36% of the RA SF chemotactic activity for PMNs, while epithelial neutrophil-activating peptide-78 accounted for 34%, and gro alpha for 28%, of this activity. Combined neutralization of all three chemokines in RA SFs resulted in a mean decrease of 50% of the chemotactic activity for PMNs present in the RA SFs. These results indicate that gro alpha plays an important role in the ingress of PMNs into the RA joint.

Arthritis, Rheumatoid↗
PubMed1995

Angiogenesis mediated by soluble forms of E-selectin and vascular cell adhesion molecule-1.

Endothelial adhesion molecules facilitate the entry of leukocytes into inflamed tissues. This in turn promotes neovascularization, a process central to the progression of rheumatoid arthritis, tumor growth and wound repair. Here we test the hypothesis that soluble endothelial adhesion molecules promote angiogenesis. Human recombinant soluble E-selectin and soluble vascular cell adhesion molecule-1 induced chemotaxis of human endothelial cells in vitro and were angiogenic in rat cornea. Soluble E-selectin acted on endothelial cells in part through a sialyl Lewis-X-dependent mechanism, while soluble vascular cell adhesion molecule-1 acted on endothelial cells in part through a very late antigen (VLA)-4 dependent mechanism. The chemotactic activity of rheumatoid synovial fluid for endothelial cells, and also its angiogenic activity, were blocked by antibodies to either soluble E-selectin or soluble vascular cell adhesion molecule-1. These results suggest a novel function for soluble endothelial adhesion molecules as mediators of angiogenesis.

Animals↗