Biomedical subjects

P Pajunen

Publications and source records attributed to P Pajunen.

8 recordsLinked to original sources

PubMed2001

Neurologic sequelae after caesarean section.

BACKGROUND: Because pregnancy increases the sensitivity of nervous tissue to local anaesthetics, pregnant patients may be at higher risk of developing neurologic deficits after spinal block than non-pregnant patients. Therefore, we evaluated prospectively the incidence and type of neurologic symptoms after spinal anaesthesia with hyperbaric bupivacaine for caesarean section. METHODS: In this prospective follow-up study we recorded neurologic complications during anaesthesia and postoperatively until discharge from the hospital of 219 patients, who underwent caesarean section under spinal anaesthesia with hyperbaric bupivacaine (5 mg/ml, mean 13 mg). The patients filled in a questionnaire on the first and fifth postoperative days. In the case of complaints typical of neurologic symptoms they were checked first by the anaesthesiologist and, in the case of persistent symptoms, afterwards additionally by a neurologist. RESULTS: Twenty-six of 219 patients were not included in the further evaluation because of incomplete return of their questionnaires. Seventeen mothers (8.8%) complained of transient neurologic symptoms (TNSs), lasting mostly 1-2 days, in the buttocks and/or legs during the first three postoperative days. Eleven patients (5.7%) complained of postdural puncture headache. Two patients (emergency caesarean section because of protracted labour in one and elective caesarean section because of previous caesarean section in the other) complained of persisting pain or sensory abnormalities. Neither of them felt paraesthesia during lumbar puncture. CONCLUSION: Women after caesarean section under a spinal block seem to suffer more often from TNSs than non-pregnant women. The conclusions are, however, uncertain since we had no control group operated on under other than spinal anaesthesia. The persisting neurologic symptoms in two patients might also be due to the obstetric procedure itself. To find out about the validity and possible underlying causes of our results, we need randomised studies with control groups receiving epidural or general anaesthesia.

Adolescent↗

PubMed2001

Cholesterol efflux capacity in vitro predicts the severity and extent of coronary artery disease in patients with and without type 2 diabetes.

OBJECTIVE: To investigate the relation between severity and extent of coronary artery disease (CAD) and in vitro cholesterol efflux capacity. DESIGN: This study consisted of 46 type 2 diabetic, and 42 nondiabetic men undergoing coronary angiography. Quantitative coronary angiography was used to estimate the severity, extent, and overall "atheroma burden" of CAD. The capacity of patient plasma to induce cholesterol efflux from cultured Fu5AH rat hepatoma cells was measured in vitro. RESULTS: In the combined study population (n = 88), there was a significant inverse correlation between efflux and global atheroma burden (r = -0.23, p < 0.05). In the diabetic group, the global atheroma burden index was independently associated both with cholesterol efflux and with LpA-I levels. However, in the nondiabetic CAD group this association was lost when efflux and LpA-I levels were included in the same model. CONCLUSION: The present study demonstrated that efflux capacity was inversely associated with the severity and extent of CAD. In the diabetic group this association was independent of LpA-I levels, suggesting impaired antiatherogenic potential of these particles in type 2 diabetic patients.

Aged↗

PubMed2001

Determinants of the severity and extent of coronary artery disease in patients with type-2 diabetes and in nondiabetic subjects.

BACKGROUND: Factors predicting the anatomic distribution and the severity and extent of coronary atherosclerosis in patients with clinically manifest coronary artery disease (CAD) for type-2 diabetic patients could be different than those for nondiabetic patients. OBJECTIVE: To study the determinants of severity and extent of CAD in consecutive patients with type 2 diabetes mellitus, compared with those for matched nondiabetic patients, undergoing clinically indicated coronary angiography. METHODS: Coronary angiograms of 48 men and seven women with type-2 diabetes and an equal number of nondiabetic subjects were analyzed quantitatively. Scores reflecting severity and extent of CAD were compared with potential risk factors using univariate correlation analyses and multivariate regression models. RESULTS: For the diabetics, a global coronary atheroma burden index was independently and directly related to age (P = 0.022) and to level of intermediate-density lipoprotein cholesterol (P = 0.055), and inversely to level of particles of a subtype of high-density lipoprotein (P = 0.022). Several angiographic indexes were related to the duration of diabetes and control of glycemia. For the nondiabetic group, global atheroma burden was independently related to age (P = 0.028), a history of hypertension (P = 0.028), and concentration of low-density lipoprotein (P = 0.013), and inversely to level of apolipoprotein A-I (P = 0.008). The duration of coronary disease and a history of smoking were also predictive of severe coronary atherosclerosis among nondiabetic patients. CONCLUSIONS: Classical risk factors are strong predictors of the severity and extent of coronary atherosclerosis in nondiabetic patients, but the most important determinants for type-2 diabetic patients are levels of triglyceride-rich lipoproteins and apolipoprotein A-I-containing particles of high-density lipoprotein, and factors directly related to diabetes.

Aged↗

PubMed2000

Angiographic severity and extent of coronary artery disease in patients with type 1 diabetes mellitus.

Studies of the characteristics of coronary artery disease (CAD) in diabetic patients have shown conflicting results. Only 2 studies exploring the severity of CAD, specifically in type 1 diabetes, have been published, and neither of them has used computer-aided quantitative coronary angiography. This retrospective study comprised 64 (24 women and 40 men) type 1 diabetic patients and nondiabetic control subjects. To estimate the severity, extent, and overall "atheroma burden" of CAD, we used quantitative coronary angiographic-based segmental analysis of coronary angiograms. Type 1 diabetic patients had greater global severity (p < 0.001), global extent (p < 0.001), and global atheroma burden (p < 0.001) indexes than nondiabetic control subjects. Quantitative coronary angiographic-derived indexes of CAD were, on average, 1.4- to 4.3-fold higher in diabetic than in nondiabetic patients. These differences were particularly marked in women. We found that type 1 diabetic patients with a clinical indication for coronary angiography, especially women, have more severe, extensive, and distal type of CAD than individually matched nondiabetic control patients. Our findings, including a loss of sex difference for CAD among type 1 diabetic patients and a marked impact of type 1 diabetes in women, are not explained by established risk factors.

Adult↗

PubMed1999

Ursodeoxycholic acid and endothelial-dependent, nitric oxide-independent vasodilatation of forearm resistance arteries in patients with coronary heart disease.

AIMS: Ursodeoxycholic acid (UDCA) has cholesterol lowering and anti-inflammatory effects and bile acids are reported to exert vasodilator effects; all of these properties might be considered desirable in a drug used in the treatment of patients with coronary heart disease. We investigated a hypothesis that UDCA may dilate arteries and the mechanism of action. METHODS: We evaluated effects of a 6-week treatment with UDCA in 11 coronary heart disease patients on endothelium-dependent (acetylcholine-induced) and -independent (nitroprusside-induced) vasodilatations in forearm vasculature by strain-gauge plethysmography. Healthy individuals (n=14) served as baseline controls. RESULTS: The percentage increase by acetylcholine in the flow of the infused arm relative to the non-infused arm of coronary heart disease patients during the trial remained unaltered, but vasodilatation to NG-monomethyl-l-arginine+acetylcholine was improved by 161+/-27% with UDCA vs 83+/-22% with placebo (mean difference 91% [95% CI 35%, 147%], P=0.016). CONCLUSIONS: Six weeks' UDCA therapy improved endothelium-dependent nitric oxide-independent vasodilatation, which might maintain arterial flow in coronary heart disease patients under conditions of impaired nitric oxide production.

Acetylcholine↗

PubMed1997

Quantitative comparison of angiographic characteristics of coronary artery disease in patients with noninsulin-dependent diabetes mellitus compared with matched nondiabetic control subjects.

The angiographic characteristics of coronary artery disease (CAD) in noninsulin-dependent diabetes mellitus (NIDDM) patients were studied by quantitative coronary angiography (QCA). Fifty-seven consecutive NIDDM patients undergoing clinically indicated elective coronary angiography and 57 nondiabetic coronary artery disease (CAD) patients were individually matched for sex, age, and body mass index. Technically adequate coronary angiograms, available for 55 subjects in each group, were analyzed with third-generation QCA software. To evaluate the anatomic severity and extent of CAD, several QCA-derived parameters were incorporated into indexes describing various per-patient features of CAD. These measures reflect CAD severity, extent, and overall "atheroma burden," and were calculated separately for different coronary segments (i.e., left main, proximal, mid, and distal segments), for the different coronary arterial territories (i.e., left main, left anterior descending, left circumflex, and right), and for the entire coronary tree. No significant differences were found between the NIDDM and nondiabetic groups (global severity index, 51 +/- 14 vs 54 +/- 13, p = NS; global extent index, 34 +/- 13 vs 32 +/- 12, p = NS; global atheroma burden index, 27 +/- 16 vs 24 +/- 12, p = NS). We also found no between-group differences in proximal, mid, or distal segments, in separate vessel territories, or in left ventricular function. Our data suggest that CAD patients, with and without NIDDM, who have similar symptoms at a given age, have similar severity and extent of CAD.

Coronary Angiography↗

PubMed1997

On neural blind separation with noise suppression and redundancy reduction.

Noise is an unavoidable factor in real sensor signals. We study how additive and convolutive noise can be reduced or even eliminated in the blind source separation (BSS) problem. Particular attention is paid to cases in which the number of sensors is larger than the number of sources. We propose various methods and associated adaptive learning algorithms for such an extended BSS problem. Performance and validity of the proposed approaches are demonstrated by extensive computer simulations.

Algorithms↗

PubMedDate not supplied

Least-squares methods for blind source separation based on nonlinear PCA.

In standard blind source separation, one tries to extract unknown source signals from their instantaneous linear mixtures by using a minimum of a priori information. We have recently shown that certain nonlinear extensions of principal component type neural algorithms can be successfully applied to this problem. In this paper, we show that a nonlinear PCA criterion can be minimized using least-squares approaches, leading to computationally efficient and fast converging algorithms. Several versions of this approach are developed and studied, some of which can be regarded as neural learning algorithms. A connection to the nonlinear PCA subspace rule is also shown. Experimental results are given, showing that the least-squares methods usually converge clearly faster than stochastic gradient algorithms in blind separation problems.

Algorithms↗