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N Epstein

Publications and source records attributed to N Epstein.

At least 19 recordsLinked to original sources
PubMed2001

Association between polymorphism in the chemokine receptor CX3CR1 and coronary vascular endothelial dysfunction and atherosclerosis.

Fractalkine, a chemokine expressed by inflamed endothelium, induces leukocyte adhesion and migration via the receptor CX3CR1, and the CX3CR1 polymorphism V249I affects receptor expression and function. Here we show that this polymorphism is an independent risk factor for atherosclerotic coronary artery disease (CAD). Genotyping of the CX3CR1-V249I polymorphism was performed in a cohort of 339 white individuals who underwent cardiac catheterization (n=197 with and n=142 without CAD, respectively). In 203 patients, intracoronary acetylcholine 15 microg/min) and sodium nitroprusside (20 microg/min) were administered to test endothelium-dependent and -independent coronary vascular function, respectively. Change in coronary vascular resistance (DeltaCVR) was measured as an index of microvascular dilation. An association was observed between presence of the CX3CR1 I249 allele and reduced prevalence of CAD, independent of established CAD risk factors (odds ratio=0.54 [95% confidence interval, 0.30 to 0.96], P=0.03). Angiographic severity of CAD was also lower in these subjects (P=0.01). Furthermore, endothelium-dependent vasodilation was greater in these individuals compared with individuals homozygous for the CX3CR1-V249 allele (DeltaCVR during acetylcholine = -46+/-3% versus -36+/-3%, respectively, P=0.02), whereas DeltaCVR with sodium nitroprusside was similar in both groups (-55+/-2% versus -53+/-2%, P=0.45). The association between CX3CR1 genotype and endothelial function was independent of established risk factors and presence of CAD by multivariate analysis (P=0.02). Thus, the CX3CR1 I249 allele is associated with decreased risk of CAD and improved endothelium-dependent vasodilation. This suggests that CX3CR1 may be involved in the pathogenesis of CAD.

Alleles↗
PubMed2001

Anterior approaches to cervical spondylosis and ossification of the posterior longitudinal ligament: review of operative technique and assessment of 65 multilevel circumferential procedures.

BACKGROUND: Multilevel anterior cervical corpectomy with fusion (ACF) offers direct resection of spondylostenosis and ossification of the posterior longitudinal ligament (OPLL) with immediate stabilization. Ideal candidates for multilevel ACF include younger patients (<65 years of age), or older individuals (>65 years of age) with loss or reversal of the cervical lordosis (kyphosis). METHODS: Sixty-five patients, averaging 56 years of age and including 40 males and 25 females, with multilevel MR- and CT-documented spondylostenosis and OPLL were studied. Preoperatively, patients exhibited moderate to severe myelopathy (average Nurick grade 3.8), and were managed with 2- to 4-level ACF with posterior wiring and fusion (PWF) procedures with halo application. The first 22 patients had no plate instrumentation, the next 22 had constrained (Orion) plates applied followed sequentially by the application of 13 semi-constrained (Atlantis) plates, and finally, 8 dynamic (ABC Aesculap) plates. RESULTS: Patients improved an average of three postoperative Nurick grades. None exhibited new cord injuries, whereas three had transient C5 root paresis. Graft/plate or vertebral fracture with extrusion were observed in 3/22 nonplated patients, 2/22 constrained-plated patients, 3/13 semi-constrained-plated patients, and 0/8 dynamic-plated patients. Fusion was documented on dynamic radiographs and 2D-CT or 3D-CT studies obtained 3 and 6 months postoperatively, or later where indicated. CONCLUSIONS: Multilevel ACF/PWF offers direct resection of spondylostenosis and OPLL with immediate maximal stabilization. Thus far, no graft/plate or vertebral body fracture or extrusions have been seen with dynamic plates, whereas the absence of plating and constrained and semi-constrained plating systems have failed.

Adult↗
PubMed2001

A new cervical spine clearance protocol using computed tomography.

OBJECTIVE: The purpose of this study was to assess a cervical spine clearance protocol for blunt trauma patients using helical computed tomographic (CT) scan of the cervical spine (C-spine). METHODS: A protocol using CT scan of the C-spine was implemented and the first 6 months of use reviewed. Patients requiring a CT scan of the head had the C-spine evaluated by lateral C-spine radiography and a helical CT scan. Patients without indication for CT scan of the head had the C-spine evaluated by three-view radiography (anteroposterior, lateral, and odontoid) with selective CT scan of the C-spine for imaging areas not well visualized or those with abnormalities identified by radiography or by clinical examination alone. RESULTS: Three hundred twenty-four patients were admitted to the trauma center after blunt trauma during the first 6 months of protocol implementation. Head CT scans were obtained in 158 patients and lateral cervical spine radiography in conjunction with helical CT scanning evaluated the C-spine. The other 166 patients had the cervical spine cleared by three-view radiography series or by clinical examination alone. For patients in whom a head CT scan was not indicated, CT scanning was used only when plain radiographs failed to adequately visualize the entire C-spine. A total of 15 injuries (4.6% of the group) were detected. Seven injuries were suspected or detected by lateral plain radiographs and confirmed by CT scan. Six patients had an injury not detected by radiography but diagnosed by CT scan, and one patient had a false-positive radiograph. Of the remaining two injuries, one was diagnosed by magnetic resonance imaging and the other by CT scan outside of the protocol. Lateral plain radiographs alone failed to detect 46% (n = 6) of all injuries. CONCLUSION: In our series, the selective use of helical CT scanning with plain radiography increased the accuracy with which cervical spine injury was detected from 54% to 100%. The protocol allowed for more rapid evaluation in many patients as well. We recommend that practice guidelines include the use of helical CT scan of the entire C-spine as the diagnostic procedure for those blunt trauma patients undergoing CT scanning of the head.

Adult↗
PubMed2000

Contribution of bradykinin receptor dysfunction to abnormal coronary vasomotion in humans.

OBJECTIVES: The aim of our study was to investigate coronary vascular kinin receptor function in patients with atherosclerosis or its risk factors. BACKGROUND: Although acetylcholine (ACH) is used as a probe for testing vascular function in vivo, endogenous bradykinin (BK) regulates resting and flow-mediated epicardial tone. METHODS: In 53 patients with mild atherosclerosis or its risk factors and 9 control subjects, endothelium-dependent vasomotion was tested with intracoronary ACH (30 microg/min) and BK (62.5 ng/min and 4 microg/min), and endothelium-independent function with sodium nitroprusside. Metabolic vasodilation was assessed during cardiac pacing (n = 19). Correlation with serum angiotensin-converting enzyme (ACE) levels and the ACE insertion/deletion genotype was performed. RESULTS: There was progressive impairment in ACH-mediated microvascular dilation with increasing numbers of risk factors (p = 0.025, analysis of variance). By contrast, BK- and sodium nitroprusside-mediated microvascular dilation was similar in all groups. Similarly, there was no correlation between epicardial coronary responses to ACH and BK; segments that constricted or dilated with ACH had similar dilator responses with BK. Bradykinin, but not ACH-mediated vasomotion, was depressed in epicardial segments that constricted with pacing. Finally, epicardial BK responses were depressed in patients with high ACE levels and in those with the ACE DD genotype. CONCLUSIONS: Endothelial dysfunction in atherosclerosis appears to be receptor-specific, involving the muscarinic receptor with relative sparing of the kinin receptor pathways. Abnormal reactivity of epicardial coronary arteries during physiologic stress is better represented by BK and not by ACH responses. Bradykinin activity and, hence, physiologic coronary vasomotion appears to be influenced by serum ACE levels and the ACE insertion/deletion genotype.

Acetylcholine↗
PubMed2000

The insertion/deletion polymorphism of the angiotensin-converting enzyme gene determines coronary vascular tone and nitric oxide activity.

OBJECTIVES: We investigated whether the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene modulates vasomotor tone and endothelial function. BACKGROUND: The deletion allele of the ACE I/D polymorphism has been associated with increased incidence of cardiovascular pathology. The risk is synergistically increased in patients who also possess the C allele at position 1,166 of the angiotensin type I (AT1) receptor gene. METHODS: In 177 patients with coronary atherosclerosis or its risk factors, we investigated endothelial function with intracoronary acetylcholine (ACH), endothelium-independent smooth muscle function with sodium nitroprusside (SNP) and basal nitric oxide activity with L-NG monomethyl arginine. RESULTS: Compared with ACE II genotype, patients with the ACE DD genotype had lower coronary microvascular and epicardial responses with SNP (coronary blood flow increase 196 +/- 26% vs. 121 +/- 11%, p = 0.003, and diameter increase 21.9 +/- 2% vs. 17 +/- 1%, p = 0.03, ACE II vs. DD, respectively). L-NG monomethyl arginine induced greater constriction in patients with the ACE DD compared with ACE II genotype (coronary blood flow -10 +/- 4% vs. 11 +/- 5%, p = 0.003, ACE DD vs. II and diameter constriction -6.3 +/- 1.2% vs. -1.9 +/- 1.2%, p = 0.01, respectively, in patients with atherosclerosis). No difference in ACH-mediated vasomotion was detected between the three ACE genotypes. The AT1 receptor polymorphism did not influence responses to either SNP or ACH. CONCLUSIONS: Patients possessing the D allele of the ACE gene have increased vascular smooth muscle tone. The enhanced tone appears to be counterbalanced by an increase in basal nitric oxide activity in patients with atherosclerosis.

Acetylcholine↗
PubMed2000

Insertion-deletion polymorphism of the ACE gene modulates reversibility of endothelial dysfunction with ACE inhibition.

BACKGROUND: The aim of this study was to examine whether angiotensin-converting enzyme (ACE) inhibition improves coronary endothelial dysfunction in patients with atherosclerosis and its risk factors and whether this was related to the ACE insertion-deletion (I/D) polymorphism. METHODS AND RESULTS: In 56 patients with atherosclerosis or its risk factors, we studied endothelium-dependent responses with acetylcholine and endothelium-independent function with sodium nitroprusside, before and after ACE inhibition with enalaprilat. Enalaprilat did not alter either resting coronary tone or vasodilation with sodium nitroprusside. However, it potentiated the coronary microvascular and epicardial responses with acetylcholine; coronary blood flow increased from 82+/-7 to 90+/-8 mL/min (P=0.05) after enalaprilat. Patients with depressed endothelial function (P<0.001) and those with ACE DD or ID genotypes (P=0.002) but not those homozygous for the I allele had the greatest improvement by multivariate analysis. Similarly, acetylcholine-mediated epicardial vasomotion improved in segments that initially constricted (endothelial dysfunction): from -10.1+/-1% to -1.4+/-2% (P<0.001) after enalaprilat. No augmentation was observed in segments that dilated (normal endothelial dysfunction) with acetylcholine. Patients with the D allele, hypercholesterolemia, and smokers (all P<0.05) had greater improvement. CONCLUSIONS: Acute ACE inhibition improves coronary epicardial and microvascular endothelium-dependent vasomotion in patients with atherosclerosis or its risk factors who have endothelial dysfunction and presence of the D allele.

Acetylcholine↗
PubMed1999

Relationship of the C242T p22phox gene polymorphism to angiographic coronary artery disease and endothelial function.

Patients with coronary artery disease (CAD) have impaired endothelial function in part due to an increase in vascular oxidant stress. p22phox, an essential component of the NADPH oxidase, is thought to play a critical role in the generation of superoxide anions in the vessel wall. The C242T polymorphism, located in the potential heme-binding site of the p22phox gene, has recently been reported to confer a protective effect on CAD risk in a Japanese study population. In a U.S. population of 252 patients (83% Caucasian) undergoing angiography for diagnosis of CAD, we investigated whether the C242T polymorphism was associated with the presence of CAD. In a subset of 142 patients, we studied whether the polymorphism manifests its potential protective effects through alteration of vascular endothelial function by measuring coronary epicardial and microvascular responses to intracoronary acetylcholine and sodium nitroprusside. Prevalence of the C242T allele was not different in 149 patients with CAD compared to 103 patients with angiographically normal coronary arteries (65.1% vs. 54.4%, P = 0.11). The C242T allele frequency in our population was nearly fourfold higher than reported previously in a Japanese population. There were also no significant differences in coronary epicardial or microvascular responses to acetylcholine or sodium nitroprusside between groups of patients with or without the C242T allele. In a U.S. population, the C242T polymorphism does not appear to confer protection from endothelial dysfunction or CAD. Am. J. Med. Genet. 86:57-61, 1999. Published 1999 Wiley-Liss, Inc.

Acetylcholine↗
PubMed1999

The interaction between marital standards and communication patterns: how does it contribute to marital adjustment?

Couples' cognitions about marriage and their communication patterns have both been found to be highly associated with marital distress. To examine the relationships among marital cognitions, communication, and marital adjustment, we had a sample of 387 community couples complete three self-report measures: the Dyadic Adjustment Scale, the Inventory of Specific Relationship Standards, and the Communication Patterns Questionnaire. Results indicated that the correlation of communication with marital adjustment is higher for women with more relationship-focused standards than for women with less relationship-focused standards; this interaction does not occur for men. The implications of the interaction and the gender difference as well as the importance of teaching communication skills, and working with associated cognitions are discussed.

Adult↗
PubMed1998

An unusual cause of low back pain? A case report.

STUDY DESIGN: Case report. OBJECTIVE: To highlight the evaluation of a patient with low back pain after an incidental radiographic finding clouded routine management. SUMMARY OF BACKGROUND DATA: Greenfield filters have been used for 20 years with good results. Complications have been seen and documented, but the natural history of filter placement in young patients is not fully appreciated. A prong from a Greenfield filter embedded within a vertebral body has been reported once as an incidental finding in a patient undergoing prophylactic monitoring for recurrence of tumor. METHODS: A 31-year-old woman had a pulmonary embolus after surgery for a benign adnexal mass. A bleeding complication occurred after systemic anticoagulation, and a vena caval filter was placed to limit the possibility of further emboli. The patient was referred to the orthopedic clinic 5 years later with low back pain and an unusual finding on computer tomographic scan: One prong of the filter was embedded within a vertebral body. RESULTS: A bone scan was obtained to evaluate the status of bone activity around the prong. Bone reaction was not evident. Conservative management of her low back pain was instituted, and after 2 years, the patient remains asymptomatic. CONCLUSION: The overall use of vena caval filters has produced favorable results, although numerous complications have been reported. All long-term sequelae have not been completely identified.

Adult↗
PubMed1998

Detection of zeta-globin chains in the cord blood by ELISA (enzyme-linked immunosorbent assay): rapid screening for alpha-thalassemia 1 (Southeast Asian type).

Fetuses with homozygous alpha-thalassemia 1, in which the deletion of all four alpha-globin genes results in the absence of any alpha-globin chains, are severely anemic with clinical features of hydrops fetalis. Definitive diagnosis of alpha-thalassemia 1 carriers is difficult since there are few red cell abnormalities. Recently Chui et al. found that minute amounts of embryonic zeta-globin chains are present in adult hemoglobin of the Southeast Asian type of alpha-thalassemia 1 carriers. In this study, we screened 521 cord bloods for alpha-thalassemia 1. Hemoglobin analysis, including quantitation of Hb Bart's, was performed using the automated HPLC, alpha-thalassemia short program (VARIANT, Bio-Rad, Hercules, CA). Of these, 200 cord blood samples in which Hb Bart's was demonstrated were tested for the presence of zeta-globin chains by ELISA using labeled anti-zeta monoclonal antibody. Zeta-globin ranged between 0.21 and 0.83% in 19 specimens carrying alpha-thalassemia 1 gene. In the remaining 90 out of 109 specimens in which Hb Bart's was greater than 1.2%, zeta-globin was less than 0.17%. DNA analysis revealed the presence of normal alpha-genotype and other types of alpha-thalassemia including alpha-thalassemia 2 and Hb Constant Spring. One false positive was found in which the zeta-globin was 0.25% by ELISA but in which PCR indicated an alpha-thalassemia 2 heterozygote. Ninety-one samples with Hb Bart's of less than 1.2% by HPLC are most likely normal with a zeta-globin range between 0 and 0.14%. This study also showed that the frequency of alpha-thalassemia 1 in Bangkok is 3.65%.

Adult↗
PubMed1998

The application of behavioral couples therapy to the assessment and treatment of agoraphobia: implications of empirical research.

The present review was undertaken to examine the literature regarding the role of the marital relationship in treatment of agoraphobia from a behavioral couples therapy (BCT) perspective. Both qualitative and quantitative analyses were conducted to evaluate (a) whether marital quality predicts treatment responsiveness and (b) how best to include the spouse in treatment of agoraphobia. Regarding the assessment of agoraphobics' relationship quality, it is recommended that subjectively experienced "satisfaction" with the relationship be distinguished from more descriptive measures of general and agoraphobia-specific relationship "adjustment." Treatment can include the partner as a "co-therapist" to assist with interventions directly targeted at the agoraphobia, or use BCT interventions to modify relationship interactions that might impede treatment gains. The application of BCT for these couples poses a number of challenges, including (a) the need to maintain a balanced treatment approach in an "unbalanced" system, (b) the need to target interventions at more than one treatment goal, and (c) the task of combining couple-focused interventions with those aimed at reducing phobic symptoms.

Agoraphobia↗
PubMed1997

Autonomy and relatedness in marital functioning.

The current investigation expands the focus of cognitive behavioral formulations of marriage by exploring the constructs of autonomy and relatedness in marriage. One hundred forty-one married couples matched to the 1990 U.S. census data on age, race, and income completed a number of self-report marital inventories including the Autonomy and Relatedness Inventory (Schaefer, Edgerton, & Burnett, 1991). Autonomy was measured by evaluating spouses' perceptions of the extent to which partners encouraged a sense of independence and individuality for the spouses. Relatedness was measured by evaluating spouses' perceptions of the amount of closeness that partners provided. It was found that autonomy and relatedness were significantly positively correlated with each other, as well as with marital adjustment for both males and females. It was found that for females, the provision of relatedness (as reported by their husbands) was significantly related to the standards that they held for the relationship. In addition, it was found that for females, the provision of relatedness (as reported by their husbands) was significantly related to the standards that husbands held for the relationship. However, no significant relationships were found between husbands' standards and relatedness (either as reported by wives or by husbands). It was concluded that it is appropriate to help couples think of autonomy and relatedness as being two important aspects of marriage that can exist together and are related to a satisfying marriage. Implications of the findings suggest that marital therapists could expand the conceptualization of marital therapy beyond being primarily relationship focused to include attention to individual needs of the spouses.

Adult↗
PubMed1996

The examination.

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Anecdotes as Topic↗
PubMed1996

Monoclonal antibody-based methods for quantitation of hemoglobins: application to evaluating patients with sickle cell anemia treated with hydroxyurea.

High-titer monoclonal antibodies (mAb) were raised against chromatographically purified human hemoglobin (Hb) species. These mAb were specific for either Hb A, Hb F, Hb S or Hb C. Based on these antibodies, which were directly conjugated with either fluorochromes or an enzyme (horseradish peroxidase), we developed immunoassays for determining the Hb profile in the peripheral blood; an enzyme-linked immunosorbent assay (ELISA) for determining the absolute and relative quantities of various Hb species and one-step immunolabeling for fluorescence microscopic and flow cytometric analyses of the distribution of RBC with respect to their Hb types. We utilized these methods for monitoring the Hb F level and the percentage of Hb F-containing cells in patients with sickle cell anemia undergoing treatment with hydroxyurea.

Anemia, Sickle Cell↗
PubMed1993

The surgical management of ossification of the posterior longitudinal ligament in 51 patients.

Ossification of the posterior longitudinal ligament (OPLL) in the cervical spine warrants unique clinical, radiographic, and surgical management. OPLL patients presenting with severe myelopathy require full assessment with both magnetic resonance imaging (MRI) and computed tomography-based (noncontrast CT, myelo-CT, three-dimensional CT) examinations to document the full extent of their disease. Whether better surgical outcomes are attained after anterior resection (diskectomy/corpectomy), rather than posterior decompression (laminectomy/laminoplasty) of OPLL remains controversial. However, our recent experience with 51 OPLL patients indicates superior results after anterior (41 patients) versus posterior (10 patients) surgery. Continuous intraoperative somatosensory evoked potential (SSEP) monitoring also appears to limit operative morbidity.

Adult↗
PubMed1992

Self-concept dimensions of clinically depressed and anxious outpatients.

Principal components analyses of the Beck Self-Concept Test (BST) were conducted independently for 288 women with primary mood disorders, 230 women with anxiety disorders, 236 men with mood disorders, and 161 men with anxiety disorders. Four self-concept dimensions that reflected (1) Intellectual Ability; (2) Work Efficacy; (3) Physical Attractiveness; and (4) Virtues/Vices occurred within the four samples. For 5-item subscales that represent these four dimensions, a two-way MANOVA found significant effects for sex and type of disorder. Women described themselves as having less intellectual ability than men did. Outpatients with mood disorders considered their physical appearance, work efficacy, and virtues/vices to be less acceptable than did those with anxiety disorders. Findings were discussed with respect to the cognitive content-specificity theory of psychopathology.

Adult↗