Biomedical subjects

N Fink

Publications and source records attributed to N Fink.

At least 19 recordsLinked to original sources

PubMed2003

Mathematical analysis of atelectasis formation in middle ears with sealed ventilation tubes.

AIM: A mathematical model was developed to identify time periods of atelectasis induction in middle ear (ME) ventilated via ventilating tubes (VT). Atelectatic ears are characterized by a total gas pressure lower than 760 mmHg. METHODS: Ventilating tubes were deliberately sealed and ME gas content changed in the presence of a preset blood gas pressure. Once sealed, CO2 rapidly diffuses out of the blood via lining tissues into the ME cleft. This results in initially a total ME pressure rise followed by a decrease in subatmospheric pressures. Time periods for atelectasis reformation was determined once ME pressure crossed the 760 mmHg value and continued to decline as the atelectasis reached higher grades. RESULTS: Time periods calculated by the model varied from 18 to 125 min in ME cavities ranging in volume from 0.5 to 3.5 mL, respectively. These results were calculated for conditions of venous blood in the lining mucosa blood and are consistent with prior clinical tests that measured an induced return to previous atelectasis state following the closure of the VT in 33 tested ears within 25-120 min (43 min on average). CONCLUSIONS: The model demonstrates that under the above conditions, diffusive gas transfer in relation to blood gas content is the leading mechanism to alterations in ME pressure and volume. It may be used as a tool to determine ME physiological cavity volume of ears with VT.

Carbon Dioxide↗

PubMed2001

Mitral annulus calcification--a window to diffuse atherosclerosis of the vascular system.

Mitral annulus calcification (MAC) is a chronic, non-inflammatory, degenerative process of the fibrous support structure of the mitral valve. It occurs more often in women and the elderly. MAC is associated with known atherosclerotic risk factors such as diabetes mellitus, hypertension and hypercholesterolemia. It is also known that patient with MAC have higher prevalence of left atrial and left ventricular enlargement, hypertrophic cardiomyopathy, atrial fibrillation, aortic valve calcification and stenosis, various cardiac conduction defects, bacterial endocarditis, cardiovascular events and stroke, though the etiological basis is unknown. Pathological studies from the 80s present a theory that MAC is a form of atherosclerosis. In order to test this theory we conducted during the last years a few clinical studies to examine the association of MAC and known atherosclerotic phenomena. We found higher prevalence of aortic atheroma in patients with MAC and atheroma thickness. We also found in MAC patients higher prevalence of carotid artery stenosis, coronary artery stenosis, peripheral artery stenosis and higher levels of beta2-Glycoprotein I antibodies in patients with MAC thickness equal or greater than 5 mm. These studies support the theory that MAC is a form of atherosclerosis and define a group of patients with higher prevalence of atherosclerotic disease in multiple blood vessels. The purpose of this review is to summarize the data concerning MAC and atherosclerotic processes, emphasizing that MAC in itself may be an atherosclerotic process.

Arteriosclerosis↗

PubMed2001

[Association between mitral annulus calcification and atherosclerosis].

Mitral annulus calcification (MAC) is best diagnosed by transthoracic echocardiography. MAC is associated with known atherosclerotic risk factors such as diabetes mellitus, hypertension and hypercholesterolemia. It is also known from the literature that patients with MAC have higher prevalence of left atrial and left ventricular enlargement, hypertrophic cardiomyopathy, atrial fibrillation, aortic valve calcification and stenosis, various cardiac conduction defects, bacterial endocarditis, cardiovascular events and stroke, though the etiological basis is unknown. Pathological studies from the 80's present a theory that MAC is a form of atherosclerosis. During the past few years we conducted a few clinical studies in order to test this theory and to examine the association between MAC and known atherosclerotic phenomena. We found higher prevalence of aortic atheroma in patients with MAC, especially complex atheroma, and we also found a continuous correlation between the MAC and atheroma thickness. We also noted that MAC patients have a higher prevalence of carotid artery stenosis, coronary artery stenosis, peripheral artery stenosis and higher levels of anti beta 2-Glycoprotein I antibodies in patients with MAC thickness equal or greater than 5 mm. These studies support the theory that MAC is a form of atherosclerosis and define a group of patients with higher prevalence of atherosclerotic disease in multiple blood vessels.

Adult↗

PubMed2001

Impact of atrial fibrillation on clinical status, atrial size and hemodynamics in patients after mitral valve replacement.

BACKGROUND AND AIM OF THE STUDY: The association between mitral valve disease and atrial fibrillation (AF) is well known, but few data exist regarding the impact of AF after mitral valve replacement (MVR) on NYHA functional class, atrial size and hemodynamic parameters. The present study was conducted to evaluate these issues. METHODS: Eighty-six patients (26 men, 60 women) who underwent MVR were evaluated by transthoracic echocardiography. Fifty-nine patients had chronic AF (AF group), and 27 were in sinus rhythm (sinus group). Variables analyzed included end-systolic left atrial and right atrial areas, tricuspid regurgitation, and presence and duration of AF. Peak and mean transprosthetic mitral valve gradients and pulmonary pressure were estimated by Doppler echocardiography. RESULTS: Groups were matched for age, sex and time from MVR (mean 6.6 years). Sixty-four patients (77%) had rheumatic heart disease, 18 (21%) had mitral valve disease, and two (2%) had mitral valve prolapse. Mean duration of AF was 11+/-12 years (range: 8-50 years). Preoperatively, AF patients had a worse NYHA class than sinus patients (2.8+/-0.8 versus 1.1+/-0.7, p = 0.001), but both had similar fractional shortening of the left ventricle and preserved prosthetic mitral valve function. Multivariate analysis identified AF as a single predictor of NYHA class after MVR. Although left and right atrial areas were larger in AF patients (47+/-25 versus 27+/-7 cm2, p = 0.0001 and 30+/-12 versus 17+/-5 cm2, p = 0.0001, respectively), the left:right atrial size ratio was not significantly different between groups. Multivariate analysis identified mean transmitral gradient and duration of AF as independent predictors of left atrial size after MVR (p = 0.01 and p = 0.0001, respectively). Tricuspid regurgitation and duration of AF were independent predictors of right atrial size (p = 0.003 and p = 0.0001, respectively). CONCLUSION: The presence of AF after MVR is associated with a worse NYHA functional class, increased transmitral gradients, and larger areas of both atria, when compared with sinus rhythm. Hence, a special effort should be made to correct arrhythmia during surgery, and in case of paroxysmal arrhythmia, earlier surgery should be considered before the condition becomes chronic.

Aged↗

PubMed2000

Relation of nonobstructive aortic valve calcium to carotid arterial atherosclerosis.

Recently it was shown that subjects with aortic valve calcium (AVC) are at increased risk for future cardiovascular disease including stroke. We hypothesized that the increased risk of stroke may be due to an association with carotid artery atherosclerotic disease. Between 1995 and 1999 our laboratory made a diagnosis of AVC without significant stenosis in 3,949 patients. Of those, 279 patients without other cardiac structural exclusion criteria (148 men and 131 women; mean age 73 +/- 9 years, range 45 to 90) underwent carotid artery duplex ultrasound for various indications, and formed the study group. Age- and sex-matched patients without AVC (n = 277), who underwent carotid artery duplex ultrasound during the same period and for the same indications, served as the control group. Compared with the control group, the AVC group had a significantly higher prevalence of carotid stenosis (> 40% to 60%, 89% vs 78% [p < 0.001]; >60% to 80%, 43% vs 23% [p <0.001];and > 80% to 100%, 32%vs 14% [p < 0.001]). The AVC group had a similar, significantly higher prevalence of > or = 2-vessel disease and bilateral carotid stenosis (stenosis levels of > 20% to 40%, >40% to 60%, > 60% to 80%, and > 80% to 100%). In multivariate analysis, AVC, but not traditional risk factors, was the only independent predictor of severe carotid atherosclerotic disease (stenosis > 80% to 100%; p = 0.0001). Thus, there is a significant association between the presence of AVC and carotid atherosclerotic disease.

Aged↗

PubMed2000

[Minocycline pneumonitis and eosinophilia].

Pneumonitis with eosinophilia is one of the less common and severe adverse effects of minocycline. The disease evolves in days or weeks from the beginning of treatment, and is usually characterized by dyspnea, fever and bilateral infiltrates in the chest X-ray. With cessation of the antibiotic, and sometimes adding cortico-steroids, clinical and roentgenological resolution follow. We present a case given minocycline for folliculitis and 3 weeks later fever, cough and shortness of breath developed. The clinical and roentgenological course was consistent with minocycline pneumonitis accompanied by eosinophilia.

Adult↗

PubMed2000

Association between mitral annulus calcification and aortic atheroma: a prospective transesophageal echocardiographic study.

BACKGROUND AND PURPOSE: Although mitral annulus calcification (MAC) has been reported to be a significant independent predictor of stroke, no causative relationship was proven. It is also known that aortic atheroma (AA), especially those >/=5 mm thick and/or protruding and/or mobile are associated with stroke. This study was designed to determine whether an association exists between MAC and AA. METHODS: We prospectively evaluated the records of 279 consecutive patients who underwent transesophageal echocardiography (TEE) for various indications to measure the presence and characteristics of AA. The 105 patients in whom a diagnosis of MAC was made on transthoracic echocardiography (TTE) immediately preceding the TEE, were compared with 174 age-matched patients without MAC. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet. We measured MAC thickness with two-dimensional-TTE in four-chamber view and AA thickness, protrusion and mobility with TEE. AA was defined as localized intimal thickening of >/=3 mm. A lesion was considered complex if there was plaque extending >/=5 mm into the aortic lumen and/or if it was protruding, mobile or ulcerated. RESULTS: No differences were found between the groups in risk factors for atherosclerosis or in indications for referral for TEE. Significantly higher rates were found in the MAC group for prevalence of AA (91 vs. 44%, P<0.001), atheromas >/=5 mm thick (68 vs. 19%, P<0.001), protruding atheromas (44 vs. 15%, P<0.001), ulcerated atheromas (10 vs. 1%, P<0.001) and complex atheroma (74 vs. 22%, P<0.001). Sixty patients had MAC thickness >/=6 mm and 45<6 mm. AA thickness was significantly greater in the patients with a MAC thickness of >/=6 mm (6.1+/-2.8 vs. 5.0+/-2.6 mm, P=0.03). On multivariate analysis MAC, hypertension and age were the only independent predictors of AA (P=0.0001, 0.005 and 0.007, respectively). CONCLUSIONS: There is a significant association between the presence and severity of MAC and AA. MAC may be an important marker for atherosclerosis of the aorta. This association may explain in part the high prevalence of systemic emboli and stroke in patients with MAC.

Adult↗

PubMed2000

Association between mitral annulus calcification and peripheral arterial atherosclerotic disease.

The authors previously demonstrated a significant association between the presence of mitral annulus calcification (MAC) and aortic atheroma, carotid atherosclerotic disease, and coronary artery disease. The present study was designed to determine whether an association exists between MAC and peripheral arterial atherosclerotic disease. Of the 805 patients in whom the diagnosis of MAC was made by transthoracic echocardiography between 1995 and 1997, 77 patients (40 men and 37 women; mean age, 73.1 +/- 11.4 years; range, 44-90 years) underwent peripheral arterial testing for various indications, and comprised the study group. They were compared with 58 age-matched and sex-matched patients without MAC (30 men and 28 women; mean age, 73.2 +/- 11.8 years; range, 31-93 years) who underwent peripheral arterial testing during the same period for the same indications (control group). MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet detected by transthoracic echocardiography. An ankle/brachial systolic pressure index (ABI) was calculated by dividing the higher dorsalis pedis or posterior tibial Doppler-derived pressures by the higher of the 2 upper extremity systolic pressures. ABI was graded as follows: normal > or = 1, abnormal < 1, mild 0.71 to 0.99, moderate 0.41 to 0.7, and severe < or = 0.4. No differences were found between the groups in indications for referral for peripheral arterial testing and in risk factors for atherosclerosis except for hypertension, which was found to be significantly more prevalent in the study group (66% vs 41%, p = 0.004). The study group included 151 limbs, and the control group included 113 limbs. The mean ABI was significantly lower for all limbs in the MAC group (0.56 +/- 0.27 vs 0.87 +/- 0.24, p = 0.0001), abnormal ABI < 1 (94% vs 68%, p = 0.001), moderate peripheral arterial disease (44% vs 25%, p = 0.001), and a severe disease (27% vs 1%, p = 0.001). Of the 77 patients with MAC, 73 (95%) had a disease (right and/or left limbs) compared with 40 of 58 (69%) in the control group (p = 0.001). Bilateral disease (Doppler index < 1 for both right and left limbs), and severe bilateral disease (Doppler index < or = 0.4 for both right and left limb) were also found to be significantly more prevalent in the MAC group (87% vs 60%, p = 0.001; and 12% vs 0%, p = 0.007, respectively). There is a significant association between the presence of MAC and peripheral arterial disease. This information strengthens our hypothesis that MAC may be an important marker for generalized vascular atherosclerotic disease.

Adult↗

PubMed1999

Tolerance to nitrates with enhanced radical formation suppressed by carvedilol.

Enhanced oxidant stress occurs under many pathophysiologic conditions (e.g., inflammation) and can be induced and mimicked by continuous nitrate therapy, eliciting increases in platelet activity, enhanced formation of reactive oxygen species (ROS), and impaired nitrate-induced vasorelaxation. Analysis was performed of effects of coinfusion of glycerol trinitrate (GTN) either with a carvedilol metabolite with antioxidant properties or with antioxidant vitamin C (Vit-C) on various hemodynamic parameters during enhanced oxidant stress associated with nitrate tolerance. Carvedilol metabolite (BM910228: 4.5 microg/kg/min) or Vit-C (55 microg/kg/min) was coadministered with GTN (1.5 microg/kg/min) for 5 days in chronically instrumented dogs. Changes in coronary diameters (CD) and other hemodynamic parameters were continuously monitored, as well as changes in platelet function. At the beginning of GTN treatment, CD increased by 9.8 +/- 0.4% and progressively declined to basal control values within 3 days. However, with additional antioxidant protection either with BM910228 or with Vit-C, the GTN-induced increase in CD was maintained (8.6 +/- 0.4% or 10.5 +/- 0.6%) and remained elevated for the entire infusion period. The thrombin-stimulated intracellular Ca2+ concentrations of platelets remained nearly unchanged during Vit-C or BM910228 in contrast to the increase with GTN. The basal cyclic guanosine monophosphate (cGMP) contents of platelets after GTN coadministered with BM910228 or with Vit-C increased on day 1 to 233 or to 250% versus control and remained at that level. Additional in vitro tests with xanthine oxidase-induced oxidant stress resulted in a more or less pronounced scavenging of O2- radicals by BM920228, Vit-C, or superoxide dismutase (SOD). Coadministration of carvedilol metabolite BM910228 or of Vit-C along with GTN suppressed noxious effects of GTN-induced oxidant stress such as increased platelet activity and impaired nitrate-induced vasorelaxation.

Adrenergic beta-Antagonists↗

PubMed1998

Mitral annular calcium detected by transthoracic echocardiography is a marker for high prevalence and severity of coronary artery disease in patients undergoing coronary angiography.

This study tests the hypothesis that mitral annular calcium (MAC) detected by transthoracic echocardiography (TTE) is a marker for high prevalence and severity of coronary artery disease (CAD) in patients undergoing coronary angiography. Pathological studies have suggested that there is an association between MAC and calcific deposits in coronary arteries; however, there are no clinical data to support this association. One hundred sixty-five patients with MAC (101 women and 64 men; mean age 71 +/- 8 years) who underwent cardiac catheterization with coronary angiography for various reasons were compared with 147 age-matched controls without MAC who underwent coronary angiography for the same indications during the same period. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet detected by TTE. Obstructive CAD was defined as either > or = 50% reduction of the internal diameter of the left main coronary artery or > or = 70% reduction of the internal diameter of the left anterior descending, right coronary, or left circumflex artery distribution. Compared with controls, the MAC group had a significantly higher prevalence of CAD (89% vs 75%, p = 0.001) and higher rates of 3-vessel disease (45% vs 24%, p = 0.001) and left main CAD (13% vs 5%, p = 0.009). Nonsignificant CAD was more common in the control group (25% vs 11%, p = 0.001). Multivariate analysis identified MAC (p = 0.0002), indications for cardiac angiography (p = 0.02), sex (p = 0.03), and diabetes mellitus (p = 0.03) as independent predictors for the presence and severity of obstructive CAD. MAC detected by TTE may be a marker for high prevalence and severity of CAD in patients undergoing coronary angiography.

Adult↗

PubMed1998

Dietary supplement with vitamin C prevents nitrate tolerance.

Enhanced formation of superoxide radicals has been proposed to play a major role in the development of nitrate tolerance in humans. We tested the effects of vitamin C (Vit-C) supplementation on glyceroltrinitrate (GTN)-induced hemodynamic effects during 3-d nonintermittent transdermal administration of GTN (0.4 mg/h) in nine healthy subjects. Tolerance development was monitored by changes in arterial pressure, dicrotic digital pulse pressure, and heart rate. Studies with GTN, Vit-C, or GTN/Vit-C were successively carried out at random in three different series in the same subjects. GTN treatment caused an immediate rise in arterial conductivity (a/b ratio of dicrotic pulse), but within 2 d of initiating GTN, the a/b ratio progressively decreased and reached basal levels. In addition, there was a progressive loss of the orthostatic decrease in blood pressure. However, coadministration of Vit-C and GTN fully maintained the GTN-induced changes in the orthostatic blood pressure, and the rise of a/b ratio was augmented by 310% for the duration of the test period. Changes in vascular tolerance in GTN-treated subjects were paralleled by upregulation of the activity of isolated platelets, which was also reversed by Vit-C administration. These findings demonstrate that dietary supplementation with Vit-C eliminates vascular tolerance and concomitant upregulation of ex vivo-washed platelet activity during long-term nonintermittent administration of GTN in humans.

Adult↗

PubMed1998

Association between mitral annulus calcification and carotid atherosclerotic disease.

BACKGROUND AND PURPOSE: It has been established that mitral annulus calcification (MAC) is an independent predictor of stroke, though a causative relationship was not proved, and that carotid artery atherosclerotic disease is also associated with stroke. The aim of this study was to determine whether there is an association between the presence of MAC and carotid artery atherosclerotic disease. METHODS: Of the 805 patients in whom the diagnosis of MAC was made by transthoracic echocardiography between 1995 and 1997, 133 patients (60 men and 73 women; mean age, 74.3+/-8 years; range, 47 to 89 years) underwent carotid artery duplex ultrasound for various indications; the study group comprised these patients. They were compared with 129 age- and sex-matched patients without MAC (57 men and 72 women; mean age, 73.6+/-7 years; range, 61 to 96 years) who underwent carotid artery duplex ultrasound during the same period for the same indications. MAC was defined as a dense, localized, highly reflective area at the base of the posterior mitral leaflet. MAC was considered severe when the thickness of the localized, highly reflective area was > or =5 mm on 2-dimensional echocardiography in the 4-chamber view. Carotid artery stenosis was graded as follows: 0%, 20%, 40%, 60%, 80%, and 100%. RESULTS: Compared with the control group, the MAC group showed a significantly higher prevalence of carotid stenosis of > or =40% (45% versus 29%, P=0.006), which was associated with > or =2-vessel disease (23% versus 10%, P=0.006) and bilateral carotid artery atherosclerotic disease (21% versus 10%, P=0.011). Severe MAC was found in 48 patients. More significant differences were found for the severe MAC subgroup (for carotid stenosis of > or =40%) in rates of carotid artery atherosclerotic disease (58% versus 29%, P=0.001), and > or =2-vessel disease (31% versus 10%, P=0.001), in addition to bilateral carotid artery stenosis (27% versus 10%, P=0.004) and even bilateral proximal internal carotid artery stenosis (21% versus 8%, P=0.015). Furthermore, significant carotid artery atherosclerotic disease (stenosis of > or =60%) was significantly more common in the severe MAC subgroup than in the controls (42% versus 26%, P<0.05) and was associated with higher rates of > or =2-vessel disease (19% versus 7%, P=0.02) and bilateral carotid artery stenosis (17% versus 7%, P=0.05). On multivariate analysis, MAC and age but not traditional risk factors were the only independent predictors of carotid atherosclerotic disease (P=0.007 and P=0.04, respectively). CONCLUSIONS: There is a significant association between the presence of MAC and carotid artery atherosclerotic disease. MAC may be an important marker for atherosclerotic disease of the carotid arteries. This association may explain the high prevalence of stroke in patients with MAC.

Aged↗

PubMed1997

Abnormal fetal cardiac axis in the detection of intrathoracic anomalies and congenital heart disease.

In a 14-month period, 409 women with singleton gestations referred for perinatal ultrasound consultation underwent evaluation of the fetal cardiac axis. Cardiac and intrathoracic anomalies were confirmed either by neonatal echocardiography or autopsy. Overall, 32 fetuses had an abnormal axis (nine, smaller axis than normal; 23, larger axis than normal). Of the 29 found to have cardiac (n = 24) or intrathoracic (n = 5) anomalies, 23 had an abnormal axis. The median cardiac axis of the normal group (44.0 degrees) was significantly smaller than that of the cardiac/intrathoracic anomaly group(60.0 degrees) (p = 0.002). The cardiac axis was independent of gestational age. The mean interobserver variation was 1.3 +/- 1.8 degrees. The sensitivity of an abnormal axis (< 28 degrees or > 59 degrees) in detecting congenital heart disease or intrathoracic anomalies was 23/29 (79.3%), with specificity of 371/380 (97.5%), positive predictive value of 23/32 (71.9%), and negative predictive value of 371/377 (98.4%). Of those with a cardiac anomaly and an abnormal axis (n = 18), five were felt to have an initial normal four-chamber view. An abnormal fetal cardiac axis, either larger or smaller than normal, is suggestive of a cardiac or intrathoracic anomaly and requires further investigation, such as fetal echocardiography. The cardiac axis should be considered with the four-chamber view in fetal ultrasound evaluation.

Adult↗

PubMed1997

Urinary NItrotyrosine Content as a Marker of Peroxynitrite-induced Tolerance to Organic NItrates.

BACKGROUND: Anti-ischemic therapy with nitrovaasodilators as NO-donors is complicated by the induction of tolerance. When nitrovasodilators are metabolized to release NO there is a considerable coproduction of oxygen-derived radicals leading to a diminished cyclic GMP production and to impaired vasomotory responses. We analyzed in vivo the glyceroltrinitrate-induced generation of strong oxidative/nitrating compounds contributing to development of tolerance. METHODS AND RESULTS: In 16 patients we studied the urinary nitrotyrosine excretion during either (1) placebo control conditions, (2) 2-day nonintermittent transdermal nitroglycerin administration (0.4 mg/h), (3) 2-day nonintermittent glyceroltrinitrate administration (0.4 mg/h) along with a continuous infusion of vitamin C (55 µg/kg/min) as an antioxidant, or (4) with vitamin C but without glyceroltrinitrate (diminished urinary nitrotyrosine content of 34 +/- 18 µg/day observed). Glyceroltrinitrate administration augmented urinary nitrotyrosine from 56 +/- 24 (basal) to 186 +/- 32 µg/day (glyceroltrinitrate tolerance). Coadministration of vitamin C caused complete elimination of tolerance and a decrease in urinary nitrotyrosine to 130 +/- 28 µg/day. Glyceroltrinitrate-induced formation of oxidants was confirmed in vitro comparing glyceroltrinitrate-induced and peroxynitrite-induced tachyphylaxis in isolated perfused rabbit hearts and analyzing tolerance-induced inactivation of solbule guanylyl cyclase in cultured aortic smooth muscle cells. CONCLUSIONS: Augmented urinary nitrotyrosine excretion during glyceroltrinitrate administration reflects enhanced formation of peroxynitrite and of nitrotyrosine. Glyceroltrinitrate-induced tolerance is the result of oxidative stress and can be suppressed by additional antioxidant therapy aimed to prevent glyceroltrinitrate-induced formation and/or actions of peroxynitrite.

Journal Article↗

PubMed1996

Laboratory assays and duplex scanning outcomes after symptomatic deep vein thrombosis: preliminary results.

PURPOSE: The purpose of this article was to assess a number of hematologic and fibrinolytic assays at the time of diagnosis of deep vein thrombosis (DVT) and at several intervals over a period of 6 months afterward and to correlate these results with the results of serial duplex scanning. METHODS: Thirty-five patients (average age 61, range 18 to 82) with acute symptomatic DVT confirmed by duplex scanning were included. On diagnosis, blood was drawn, and plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor (PAI), D-dimer (DD), and tissue factor pathway inhibitor (TFPI) were determined. Duplex scanning and all laboratory assays were repeated 1 week, 1 month, 3 months, and 6 months thereafter. RESULTS: The rate of DVT complete resolution 6 months after diagnosis was 57%. Whereas plasma levels of PAI were similar throughout the 6-month follow-up period, t-PA increased significantly 1 week after diagnosis and decreased thereafter. Both DD and TFPI levels decreased significantly after diagnosis compared with presentation values. Comparing these assay levels between patients with complete resolution versus partial or no resolution, PAI levels were significantly higher during the first week in patients with poor outcome. Plasma levels of t-PA were higher in cases with good outcome, and DD levels were higher in patients with poor outcome. TFPI levels were similar in both outcome groups. CONCLUSIONS: Patients with complete DVT resolution on duplex scanning at 6 months had significantly lower levels of PAI on presentation and after 1 week than did those with incomplete lysis. Although differences were not significant, t-PA levels were higher and DD lower in patients with good outcome. Our results suggest that certain plasma fibrinolytic assays might correlate with the outcome of DVT, as assessed by duplex ultrasonography.

Adolescent↗

PubMed1995

The association of lymphocytotoxic antibodies with corneal allograft rejection in high risk patients. The Collaborative Corneal Transplantation Studies Research Group.

The Collaborative Corneal Transplantation Studies are a pair of multicenter prospective clinical trials evaluating the effectiveness of histocompatibility matching in high risk keratoplasty patients. The antigen matching study (AMS) evaluated HLA matching in patients without circulating lymphocytotoxic antibody to HLA antigens and the cross-match study (CS) evaluated the effect of using cross-match-negative donors in patients with identified circulating lymphocytotoxic antibodies to HLA antigens. Sera from 510 patients considered for enrollment in the studies were screened preoperatively for the presence of anti-class I lymphocytotoxic antibodies (LA). The 42 patients (8%) found to have detectable LA entered the CS. The 468 patients found not to have detectable LA preoperatively entered the AMS. Fifteen of the 37 transplanted CS patients were found to have donor-specific anti-class I antibody (before or after surgery). These patients were also screened for anti-class II LA and 25 had anti-class II panel reactive antibody > or = 5%. Forty-nine of the 419 transplanted AMS patients (12%) were found to have produced anti-class I LA after surgery, and in 19 patients, antibody specificities were those of donor HLA antigens. There was a significant association between the number of mismatched class I antigens and the number of donor-specific LA produced. The production of LA by AMS patients was significantly associated with reaction episodes; eighty-two percent of patients (40 of 49) with LA had reaction, compared with 63% of patients (230 of 365) without LA (P = 0.02). Likewise, production of donor-specific LA was significantly associated with immune-mediated graft failure (P = 0.025). For CS patients, there was no correlation between the production of donor-specific anti-class I or nonspecific anti-class II antibodies and graft outcome. However, the CS patients had poorer graft survival than did AMS patients at 3 years (57% vs. 66%, P = 0.01). These data demonstrate that LA, especially directed against donor class I HLA antigens following corneal transplantation in high risk patients, are associated with immune graft rejection and can be an indicator of allograft rejection.

Antilymphocyte Serum↗

PubMed1994

Effectiveness of histocompatibility matching in high-risk corneal transplantation: a summary of results from the Collaborative Corneal Transplantation Studies.

The Collaborative Corneal Transplantation Studies (CCTS) were designed to evaluate the effect of donor-recipient histocompatibility matching and crossmatching on the survival of corneal transplants in high-risk patients. Corneas were allocated to the 419 patients in the double-masked Antigen Matching Study on the basis of HLA-A,-B and HLA-DR antigen match. ABO blood group compatibility was determined but not used for recipient selection. The 37 patients in the Crossmatch Study were randomly assigned to receive a cornea from either a positively or negatively crossmatched donor. All patients received topical steroid therapy according to a standard protocol. Matching for HLA-A,-B and HLA-DR antigens had no effect on overall graft survival, the incidence of irreversible rejection, or the incidence of rejection episodes. The positive group in the Crossmatch Study had fewer graft failures, rejection failures, and rejection episodes than the negative group; however, these differences were not statistically significant. The estimated proportion of eyes with failure from rejection by 3 years was 30% for the ABO-incompatible group and 16% for the ABO-compatible group (relative risk, 1.98; 95% confidence interval, 1.15 to 3.13). These studies demonstrate that, for high-risk patients who are immunosuppressed by topical steroid therapy: 1) neither HLA-A.-B nor HLA-DR antigen matching substantially reduced the likelihood of corneal graft failure; 2) a positive donor-recipient crossmatch did not increase the risk of corneal graft failure; and 3) ABO blood group matching may be effective in reducing the risk of graft failure from rejection.

ABO Blood-Group System↗

PubMed1985

The cardiac patient and exercise: a sociobehavioral analysis.

Health beliefs (health motivation, perceptions of illness, perceptions of resusceptibility, efficacy of treatment, barriers to treatment, and cues to taking health-related action), HLOC, patient satisfaction, social support, and self-motivation were studied in a group of cardiac patients (N = 41; 39 men and two women) who initiated and completed a phase II outpatient cardiac exercise program. Twenty-three had MI and 18 had CABG. They ranged in age from 34 to 75 years with a mean age of 53 1/2 years. Regarding health beliefs, the only subscales not reflecting the tendency toward compliant behavior were general health motivation and cues to taking health-related action. Scores on the remaining measures revealed a tendency for subjects to be externally controlled, satisfied with the program and staff, recipients of social support, and self-motivated. Although it was anticipated that patients with MI would differ significantly from patients who had CABG regarding these measures, this was not found to be true. A correlation matrix revealed that the most remarkable relationships were those between perceptions of severity of illness and general health motivation; HLOC and general health motivation; perceptions of severity and resusceptibility; cues to taking health-related action and satisfaction with the program staff; and satisfaction with the program and the program staff. Interestingly, perceptions of resusceptibility were negatively related to social support and self-motivation.

Adult↗