Laser-irradiating infrared attenuated total reflection spectroscopy of articular cartilage: Potential and challenges for diagnosing osteoarthritis.

Objective: A prototype infrared attenuated total reflection (IR-ATR) laser spectroscopic system designed for in vivo classification of human cartilage tissue according to its histological health status during arthroscopic surgery is presented. Prior to real-world in vivo applications, this so-called osteoarthritis (OA) scanner has been tested at in vitro conditions revealing the challenges associated with complex sample matrices and the accordingly obtained sparse spectral datasets. Methods: In vitro studies on human knee cartilage samples at different contact pressures (i.e., 0.2-0.5 â€‹MPa) allowed recording cartilage degeneration characteristic IR signatures comparable to in vivo conditions with high temporal resolution. Afterwards, the cartilage samples were assessed based on the clinically acknowledged osteoarthritis cartilage histopathology assessment (OARSI) system and correlated with the obtained sparse IR data. Results: Amide and carbohydrate signal behavior was observed to be almost identical between the obtained sparse IR data and previously measured FTIR data used for sparse partial least squares discriminant analysis (SPLSDA) to identify the spectral regions relevant to cartilage condition. Contact pressures between 0.3 and 0.4 â€‹MPa seem to provide the best sparse IR spectra for cylindrical (d â€‹= â€‹3 â€‹mm) probe tips. Conclusion: Laser-irradiating IR-ATR spectroscopy is a promising analytical technique for future arthroscopic applications to differentiate healthy and osteoarthritic cartilage tissue. However, this study also revealed that the flexible connection between the laser-based analyzer and the arthroscopic ATR-probe via IR-transparent fiberoptic cables may affect the robustness of the obtained IR data and requires further improvements.

Effects of occupational cobalt exposure on the heart in the production of cobalt and cobalt compounds: a 6-year follow-up.

OBJECTIVE: It has been suspected that cobalt is toxic to the heart. It can cause cardiotoxicity in heavily exposed humans and in experimental systems. The issue of interest for this study is whether cobalt also affects the myocardium at occupational exposure levels. METHODS: To study the effect of occupational cobalt exposure on the heart, we conducted a follow-up of workers at a cobalt production plant. The workers' hearts had been examined by echocardiography in 1999-2000. Altogether 93 exposed and 49 non-exposed workers examined in 1999-2000 were re-examined in 2006. Occupational history and health data were collected with a questionnaire. Blood pressure was measured, and electrocardiography (ECG), laboratory tests, Holter registration, and echocardiography were conducted for all participants. Analysis of covariance (ANCOVA) was used to analyse the data. RESULTS: No differences were found between the exposed and unexposed groups for any of the echocardiographic parameters in 2006. There were no differences in the laboratory values, the ECG parameters, or the results of the Holter registration of the exposed and unexposed workers. CONCLUSIONS: Although the previous results in 2000 suggested an association between cumulative exposure to cobalt and echocardiographic findings, the results of this new cross-sectional study with a tissue Doppler 6 years later did not confirm the association in the present cohort. If cobalt exposure affects heart muscle functions at this exposure level, the effects are smaller than those caused by physiological changes due to ageing, medication, and traditional cardiovascular risk factors, such as elevated blood pressure.

Serum matrix metalloproteinase-9 and venous bypass graft occlusion.

OBJECTIVE: The primary results after coronary artery bypass grafting are good, but early clinical events as a result of graft occlusion are still a problem. Early occlusions are thought to be due to thrombosis or fibrointimal hyperplasia superimposed by thrombosis, but the etiology of these phenomena is not fully understood. Matrix metalloproteinase-9 has been suggested to have a role in graft occlusion ex vivo. MATERIAL AND METHODS: We investigated whether the level of serum matrix metalloproteinase-9 reflects its proposed role in occlusion of vein grafts. The study population consisted of 30 men with a history of myocardial infarction and 31 men without myocardial infarction who had undergone coronary artery bypass grafting. All the men were asymptomatic. RESULTS: Among the patients with no previous myocardial infarction, serum matrix metalloproteinase-9 level was significantly higher in those with graft occlusion than in those without occlusion (54.0+/-11.0 microg/L and 41.7+/-10.4 microg/L, respectively, p = 0.006), and it correlated positively with the number of occluded grafts (R = 0.55, p = 0.001). In the patients with myocardial infarction, this effect was not detected. CONCLUSIONS: Serum matrix metalloproteinase-9 reflected the occurrence of vein graft occlusion in subjects with no previous history of myocardial infarction.

Atrial fibrillation in elderly patients after coronary artery bypass grafting; gender differences in outcome.

OBJECTIVES: To evaluate gender-related differences in preoperative risk factors, hospital events, especially atrial fibrillation (AF), and length of stay in elderly patients undergoing isolated coronary artery bypass grafting (CABG). DESIGN: Prospectively collected data from consecutive patients undergoing isolated CABG in Tampere University Hospital between May 1999 and November 2000, in total 1131 patients. RESULT: We analysed 621 patients 65 years and older of whom 401 (65%) were male. When evaluating gender differences we found that the women were older (73 vs. 71 yrs, p<0.001) and significantly more often had hypertension (66% vs. 49%, p<0.001) and chronic heart insufficiency (11% vs. 4%, p=0.001). The NYHA classification of the women was worse (3.4 vs. 3.1, p<0.001) and in the angiographic data they had left main stenosis more often (31% vs. 21%, p=0.005) than the men. The women needed longer hospitalisation (19 vs. 15 days, p<0.001). There was no difference in the prevalence of postoperative AF between the genders, but in spite of that women had more postoperative strokes (6% vs. 3%, p=0.028) and also other major complications (29% vs. 19%, p=0.004) than the men. The 30-day mortality was higher in the female group (8% vs. 5%, p=0.06). We analysed preoperative risk factors and found that the females had a 1.6-fold risk for postoperative major complication after adjustment for age and other risk factors. In a logistic regression analysis age and the number of anastomoses emerged as independent predictors of AF in males, but in females we could not find any predictor for postoperative AF. CONCLUSIONS: The women are older and have more comorbidities and risk factors at the time of CABG. They also have more postoperative complications, but not a significantly higher mortality. Importantly, the excess of morbidity remains after adjustment for age and underlying risk factors. There is no gender difference in the incidence of postoperative AF in the elderly population. However, it seems to occur independent of age in the women only.

Patients' fears in coronary arteriography.

This study was concerned with the objects of fear and the intensity of fears related to coronary arteriography (CA) in 378 patients scheduled for coronary arteriography at a university hospital. Intensity of fear was measured on a 10-point Likert-type scale which listed 26 objects of fear. The patients were asked to assess the intensity of their fears both before and after CA. The results showed that the intensity of fear varied depending upon the object of fear. The highest intensity was recorded for fear of coronary artery bypass surgery. A significant increase was found in fear of lying flat in bed after CA and fear of not receiving social support. Fears of uncertainty about the illness, the CA procedure, results of CA, pain, coronary artery bypass surgery and coronary angioplasty decreased significantly after CA. Significant associations were found between objects of fear and patient demographics. It is concluded that patients' fears should be assessed individually both before and after CA. Special attention should be paid to the fears of women, patients under 45 years, upper and lower level employees and the unemployed.

Associations between lipoproteins and the progression of coronary and vein-graft atherosclerosis in a controlled trial with gemfibrozil in men with low baseline levels of HDL cholesterol.

BACKGROUND: Lipid-lowering secondary-prevention trials of coronary artery disease (CAD) have implicated triglyceride-rich lipoproteins as the main determinants of angiographic progression after elevated LDL cholesterol levels have been lowered with therapy. The present study focuses on the lipoprotein determinants of angiographic CAD progression in men with low HDL cholesterol concentration as their main baseline lipid abnormality who underwent 32 months of randomized therapy with gemfibrozil or placebo. METHODS AND RESULTS: Men who had undergone coronary bypass surgery (n=372) completed a randomized, placebo-controlled study with gemfibrozil 1200 mg/d. They were selected primarily for HDL cholesterol levels that corresponded to the lowest third for middle-aged men. Average baseline lipid and lipoprotein levels were serum triglyceride, 1.60; serum cholesterol, 5.17; ultracentrifugally separated LDL cholesterol, 3.43; HDL2 cholesterol, 0.41; and HDL3 cholesterol, 0. 61 mmol/L. In the gemfibrozil group, these levels were reduced on average by 40%, 9%, and 6% or increased by 5% and 9%, respectively. On-trial IDL and LDL triglyceride and cholesterol levels significantly predicted global angiographic progression, taking into account changes in native segments and in bypass grafts. HDL3 but not HDL2 cholesterol concentration was associated with protection against progression, especially focal disease in native coronary lesions. VLDL was the lipoprotein most predictive of new lesions in vein grafts; IDL was also significantly related. CONCLUSIONS: This study expands the previous evidence of the triglyceride-rich lipoproteins, especially IDL, as predictors of angiographic progression of CAD but does not negate the significance of mildly elevated LDL levels. Of the HDL subfractions, only HDL3 was protective in this group of men selected for their low initial HDL levels.

Prevention of the angiographic progression of coronary and vein-graft atherosclerosis by gemfibrozil after coronary bypass surgery in men with low levels of HDL cholesterol. Lopid Coronary Angiography Trial (LOCAT) Study Group.

BACKGROUND: Studies have shown that treatment of hyperlipidemia, especially lowering of plasma LDL levels, retards the progression of coronary atherosclerosis and prevents clinical cardiovascular events. No such studies have focused on subjects with low levels of HDL cholesterol. METHODS AND RESULTS: We randomly assigned 395 post-coronary bypass men, who had an HDL cholesterol concentration < or = 1.1 mmol/L and LDL cholesterol < or = 4.5 mmol/L, to receive gemfibrozil 1200 mg/d or placebo. Coronary angiography was performed at baseline and after, on average, 32 months of therapy. Changes in coronary dimensions were assessed by computer-assisted analysis. Average on-trial serum triglyceride concentrations were 1.69+/-0.68 and 1.02+/-0.37, total cholesterol 5.48+/-0.68 and 4.83+/-0.63, LDL cholesterol 3.84+/-0.59 and 3.39+/-0.56, and HDL cholesterol 0.88+/-0.15 and 0.98+/-0.17 mmol/L in the placebo and gemfibrozil groups, respectively (mean+/-SD, each P<.001). The change in per-patient means of average diameters of native coronary segments was -0.04+/-0.11 mm in the placebo group and -0.01+/-0.10 mm in the gemfibrozil group (P=.009). The equivalent changes in minimum luminal diameters of stenoses were -0.09+/-0.18 and -0.04+/-0.15 mm, respectively (P=.002). A similar, albeit nonsignificant, trend toward treatment benefit was found in the predefined primary study end point, segments unaffected by grafts and those distal to graft insertions. In aortocoronary bypass grafts, 23 subjects (14%) assigned to placebo had new lesions in the follow-up angiogram, compared with 4 subjects (2%) assigned to gemfibrozil (P<.001). CONCLUSIONS: Gemfibrozil therapy retarded the progression of coronary atherosclerosis and the formation of bypass-graft lesions after coronary bypass surgery in men with low HDL cholesterol as their main lipid abnormality.