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At least 649 records · Page 36Linked to original sources

PubMed2001

Impairment of cardiac autonomic function in patients with Duchenne muscular dystrophy: relationship to myocardial and respiratory function.

BACKGROUND: Previous studies reported an impairment of nervous autonomic activity in patients with Duchenne muscular dystrophy (DMD). However, the relationship of the autonomic dysfunction to the impairment of cardiac mechanical function and of respiratory failure is not completely understood. METHODS: We evaluated cardiac autonomic function by time- and frequency-domain heart rate variability (HRV) analysis on 24-hour Holter recordings in 60 patients with DMD (16.8 +/- 4.8 years) and 28 healthy control patients (15.2 +/- 4.6 years, P = not significant). The circadian rhythm of R-R interval, low frequency, high frequency, and low-frequency/high-frequency ratio was also assessed. In all patients, left ventricular ejection fraction was measured by 2D echocardiography; respiratory function was assessed by spirometry. RESULTS: All HRV parameters were lower in patients with DMD than in control subjects, with the percentage of differences between adjacent R-R intervals >50 ms (11.6% +/- 8.5% vs 27.3% +/- 14.1%, P =.00001) and high frequency (23.9 +/- 10.3 ms vs 36.1 +/- 12.2 ms, P =.0001) showing the strongest differences. A significant circadian rhythm of HRV variables was present in both groups, but it was considerably flattened in patients with DMD. There was no correlation between left ventricular ejection fraction and HRV indexes except for a weak correlation with high frequency (r = 0.30, P =.02) and with low-frequency to high-frequency ratio (r = -0.29, P <.03). Similarly modest correlations were found between forced vital capacity and high frequency (r = 0.4, P =.007) and low-frequency/high-frequency ratio (r = -0.32, P =.026). Multiple regression analysis did not show any independent predictive variable for the autonomic impairment. CONCLUSIONS: Our data show a marked impairment of cardiac autonomic function in patients with DMD, which appears to mainly involve the parasympathetic branch and appears to have a multifactorial origin.

Adolescent↗

PubMed1983

Hypothalamic-pituitary-gonadal function in relation to liver function in men with alcoholic cirrhosis.

Serum concentrations of oestrone, oestradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), and sex hormone-binding globulin (SHBG) were significantly (P less than 0.01) raised in men with alcoholic liver cirrhosis (no. = 42) compared with age-matched controls (no. = 20). No significant difference was observed when comparing serum testosterone concentrations. Patients were divided into three groups in accordance with the severity of liver cirrhosis, using biochemical and clinical criteria. Patients with the best-preserved liver function (no. = 11) and patients with moderately affected liver function (no. = 18) had significantly (P less than 0.05) raised serum concentrations of testosterone, FSH, and LH when compared with both controls and patients with severely affected liver function (no. = 13). Serum concentrations of testosterone, FSH, and LH in the latter group showed no significant differences from the controls. Serum concentrations of oestrone and oestradiol were significantly (P less than 0.05) increased in all patient groups, and serum oestrone increased with decreasing liver function. No significant differences were observed concerning SHBG concentrations in the three groups of patients. Dexamethasone suppression did not change the concentration of testosterone significantly, but oestrone and oestradiol concentrations decreased significantly (P less than 0.01) in controls and patients. In patients, but not in controls, a significant (P less than 0.01) increase in FSH and LH concentrations was observed after dexamethasone suppression. The mean percentage increase of FSH and LH was higher the greater the severity of liver cirrhosis.

Adult↗

PubMed2004

Review of preoperative functional evaluation for lung resection using the right ventricular hemodynamic functions.

Surgery for patients with lung cancer diminishes their lung functions, due to removal of their lung lobes. Therefore, thoracic surgeons have to consider postoperative lung function of patients. In this review, we explained recent approaches of estimation of postoperative lung function by spirometrical and also pulmonary circulatory measurement values. The most common and simple way to estimate postoperative conditions for patients who undergo lung resections is calculated by numbers of segments that are removed by surgery. However, these methods are not so accurate when the patients have chronic obstructive pulmonary disease. Another method for estimating postoperative conditions using right heart catheterization is a unilateral pulmonary arterial occlusion (UPAO) test. Applying this method, surgery related deaths have been decreased. Since, UPAO test mimics the postoperative state by occluding the pulmonary artery prior to lung surgery, it is supposed to be very accurate. Recently, a novel method to estimate postoperative right heart reserve functions was developed. Using this method, postoperative right heart failures can be anticipated prior to lung resections. In this review, we explain these kinds of methods to prevent impairment of postoperative quality of life.

Heart Failure↗

PubMed1991

Primary biliary cirrhosis: relation between hepatic function and pulmonary function in patients who never smoked.

We studied the relationship between selected variables of hepatic and pulmonary function in 47 patients with primary biliary cirrhosis, who were participating in a prospective study to assess sequential pulmonary function at yearly intervals. An additional 20 patients with primary biliary cirrhosis, who were liver transplant candidates awaiting transplantation, were studied. None of the 67 patients ever smoked cigarettes. Severity of primary biliary cirrhosis was characterized by histological stage and the Mayo risk score derived from a Cox regression model that used the following variables: serum bilirubin and serum albumin levels, age, prothrombin time and clinical severity of edema. Pulmonary function assessment included key variables describing expiratory airflow (forced expiratory volume in 1 sec divided by forced vital capacity) and efficiency of gas exchange (steady-state diffusing capacity for carbon monoxide). We found a significant relationship between histological stage of primary biliary cirrhosis and steady-state diffusing capacity (p = 0.02) and between the Mayo risk score for disease severity and steady-state diffusing capacity (p = 0.03). Progressive deterioration of steady-state diffusing capacity was associated with increasing severity of primary biliary cirrhosis. No relationship existed between pulmonary function and the presence of sicca complex or Sjögren's syndrome or the clinical manifestations of portal hypertension (e.g., esophageal varices, ascites and splenomegaly). No significant relationship existed between expiratory airflow and severity of primary biliary cirrhosis. We conclude that in patients with primary biliary cirrhosis who have never smoked, a statistically significant relationship exists between the severity of the liver disease and the efficiency of gas exchange measured by steady-state diffusing capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗

PubMed1998

[The influence of left systolic ventricular function on right ventricular function after an acute myocardial infarct].

The aim of this study was to assess the interaction between left ventricular and right ventricular systolic function after acute myocardial infarction (AMI). The study population comprises 27 normal subjects and 71 patients assessed at predischarge (12 +/- 7 days) after AMI and divided into two subgroups, 24 with inferior AMI and 47 with non inferior AMI. The three groups were comparable for sex, age, heart rate and blood pressure. Right ventricular function was evaluated by two-dimensional assessment of tricuspid annular plane systolic excursion (TAPSE) and by Doppler analysis of right ventricular outflow tract. Left ventricular systolic function was evaluated by two-dimensional determination of ejection fraction and wall motion score index, and by Doppler analysis of left ventricular outflow tract. The overall AMI population showed reduced TAPSE, velocity-time integral (both p < 0.05) and peak velocity (p < 0.005) of right ventricular outflow tract, prolongation of Q-S2 interval and increase of pre-ejection period/acceleration time ratio (both p < 0.05) in comparison with normals. These alterations were accompanied by a decrease of left ventricular ejection fraction and increase of wall motion score index. (p < 0.0001) The changes of right ventricular indexes were confirmed in patients with inferior AMI who had also lower left ventricular ejection fraction (46 +/- 9%). Functional parameters of the right ventricle were not significantly modified in patients with non inferior AMI who had greater left ventricular ejection fraction (53 +/- 8.6%). In the overall AMI population, and in particular in inferior AMI, we found univariate relations between time-velocity integrals of left ventricular and right ventricular outflow tract and between left ventricular ejection fraction and TAPSE. Only in inferior AMI creatinkinase peak was related to time-velocity integral of right ventricular outflow tract (r = -0.59, p < 0.01). In conclusion, the magnitude of right ventricular systolic impairment developing after left ventricular AMI depends on the degree of left ventricular dysfunction, likewise by changes of hemodynamic load imposed to the right ventricle. AMI location and, only in inferior AMI, infarct extension participate in determining this dysfunction.

Analysis of Variance↗

PubMed1997

Quantitative liver function tests define the functional severity of liver disease in early-stage cirrhosis.

Some patients with early-stage cirrhosis preserve hepatic function, whereas others have little hepatic reserve and rapidly deteriorate. The aim of this study was to use quantitative tests of liver function (QLFTs) to define the degree of functional hepatic impairment in patients with early-stage cirrhosis (Child-Pugh score 5-7) and to determine whether the tests predicted subsequent hepatic decompensation. We recruited 10 cirrhotic (Cr) patients and 10 healthy controls (NI), who were well matched for race, age, weight, and gender. Clearances of caffeine (CF) and antipyrine (AP) after oral administration were measured from timed samples of saliva. The clearance of cholate (CA) was measured from serum samples obtained after simultaneous oral ([2,2,4,4-2H]CA) and intravenous ([24-13C]CA) administration. CA shunt was calculated as (Cl i.v./Clo x 100%). CF elimination rate (Cr v NI, mean +/- SD: 0.03 +/- 0.02 v 0.075 +/- 0.018 h-1, P < .0005) and AP clearance (24 +/- 16 v 40 +/- 7 mL/minute, P < .02) were reduced in Cr patients. CA shunt was increased in Cr patients (43 +/- 18 v 18 +/- 7%, P < .002). Five Cr patients decompensated during follow-up and had the worst CA shunts (76%, 66%, 51%, 48%, and 45%). Three subsequently received successful orthotopic liver transplantation, 1 died of hepatoma, and 1 is on the waiting list for transplantation. In conclusion, QLFTs define the degree of functional impairment in early cirrhosis and may identify Cr patients at greatest risk of decompensation who may require transplantation for survival.

Administration, Oral↗

PubMed1982

B cell function in patients with chronic pancreatitis and its relation to exocrine pancreatic function.

Exocrine pancreatic function was evaluated by a Lundh meal test and a secretin-cholecystokinin test in 16 patients with chronic pancreatitis. B cell function was assessed by measuring the concentration of C-peptide after stimulation with oral glucose and intravenous glucagon. The Cc-peptide response to intravenous glucagon and oral glucose was closely correlated (r = 0.88, p less than 0.01). Plasma C-peptide after glucagon was significantly correlated to the post-prandial concentration of lipase (r = 0.72, p less than 0.001), amylase (r = 0.64, p less than 0.05) and to amylase output (r = 0.64, p less than 0.05). Eight out of nine patients treated with insulin had residual B cell function, but it diminished significantly with increasing duration of diabetes. We conclude that B cell function is correlated to pancreatic enzyme secretion and that patients with insulin-treated diabetes secondary to chronic pancreatitis have a residual insulin secretion similar to that of patients with Type 1 (insulin-dependent) diabetes.

Adult↗

PubMed1995

Estimation of overall pulmonary function after irradiation using dose-effect relations for local functional injury.

PURPOSE: To predict the pulmonary function 3-4 months after irradiation for malignant lymphoma from the three-dimensional (3-D) dose distribution. METHODS: Dose-effect relations for the relative reduction of local perfusion (Q) and local ventilation (V), were calculated in 25 patients, using correlated SPECT (Single Photon Emission Computed Tomography) and CT data. By combining the 3-D dose distribution of an individual patient with the dose-effect relations averaged over all patients, the average reduction of local Q and V (i.e., the overall response parameters) in the whole lung was estimated for each patient. Correlation coefficients were calculated between these overall response parameters and the change in standard lung function tests. In addition, the relation between the overall response parameters and the incidence of radiation pneumonitis was determined. RESULTS: The overall response parameter for perfusion was correlated with the change in standard lung function tests, with correlation coefficients varying between 0.53 (p = 0.007) and 0.71 (p < 0.001) for the change of Vital Capacity and Forced Expiratory Volume at 1 s, respectively. For the overall response parameter for ventilation similar correlations were observed. Four out of the 25 patients developed radiation pneumonitis; in these four patients the overall response parameter for perfusion was on average somewhat higher (13.2 +/- 1.4% (1 standard error of the mean)) than in patients without radiation pneumonitis (10.5 +/- 1.0%), but this difference was not significant. A higher incidence of radiation pneumonitis was observed for larger values of the overall response parameter for perfusion; in patient groups with an overall response parameter for perfusion of 0-5%, 5-10%, 10-15%, and 15-20%, the incidence of radiation pneumonitis was 0 (0/1), 10 (1/10), 13 (1/8) and 33% (2/6), respectively. CONCLUSION: By combining the 3-D dose distribution with the average dose-effect relations for local perfusion or ventilation, an overall response parameter can be calculated prior to irradiation, which is predictive for the radiation-induced change in the overall pulmonary function, and possibly for the incidence of radiation pneumonitis, in this group of patients.

Adolescent↗

PubMed2006

Alterations in left ventricular structure and function in type-1 diabetics: a focus on left atrial contribution to function.

This study was designed to determine the effects of type 1 diabetes mellitus (T1DM) on left ventricular (LV) and particularly left atrial (LA) structure and function. We evaluated 88 non-obese subjects: 44 with T1DM, 44 age- and gender-matched normal controls (age 39 +/- 11 years). LV and LA structure and function were quantified using two-dimensional echocardiography, pulse-wave Doppler, and tissue Doppler imaging, including early and late diastolic myocardial velocities (Em global and Am global, respectively). The T1DM subjects averaged higher heart rate, relative wall thickness, and ejection fraction, and lower indexed end-systolic volume than normal controls (P < .001, P < .05, P = .01, and P < .05, respectively). T1DM was related to A wave velocity, Am global, A wave integral, LA ejection fraction, and LA systolic ejection fraction (P < .01, P < .05, P < .0005, P < .001, and P < .0005, respectively). In multivariate analyses, T1DM was an independent predictor of the A wave integral, LA ejection fraction, and LA systolic ejection fraction (P < .01, P < .01, and P < .005, respectively). Thus, despite increased relative wall thickness, LV systolic function is increased and early diastolic filling is normal in T1DM subjects; however, they possess changes in LA transport function suggesting increased reliance on LA contribution to LV filling.

Adolescent↗

PubMed2004

Effects of thyroxin therapy on cardiac function in patients with subclinical hypothyroidism: index of myocardial performance in the evaluation of left ventricular function.

OBJECTIVE: We investigated the effects of thyroxine (T4) therapy on the cardiac function in subclinical hypothyroidism (SHT) by using the index of myocardial performance (IMP) and the conventional echocardiographic parameters. METHODS: Forty-five SHT patients (F/M:38/7, age 39.9+/-7.9) and 29 healthy subjects (F/M:25/4, age 38.3+/-8.6) were studied. Patients were randomly assigned, in a double-blind manner to receive T4 therapy (group I) or a placebo (group II) and for a period of up to 12 months, were followed up using thyroid function tests and both conventional and Doppler echocardiographic measurements. RESULTS: At the baseline, the SHT patients has a significantly higher isovolumic relaxation time (IRT) (98.3+/-23.7 vs. 81.7+/-14.7<0.01), IMP (0.52+/-0.06 vs. 0.42+/-0.05; P<0.001), A max (late mitral peak velocity) (83.4+/-12.6 vs. 74.3+/-13.5; P<0.01) and significantly lower (early mitral peak velocity) Emax/Amax ratio (1.19+/-0.18 vs. 1.34+/-0.17; P<0.01) than the individuals in the control group. In group I, the thyroid hormone profile became normalized after 1 year of L-T4 therapy, but there was no significant change in the left ventricular (LV) morphology or systolic function. After 1 year of follow-up, group I showed a significant reduction of MPI (0.53+/-0.05 vs. 0.42+/-0.07; P<0.001), Amax (84.2+/-13.7 vs. 74.5+/-11; P<0.001) and IRT (98.6+/-23.7 vs. 82.9+/- 23.3; P<0.001) along with a normalization of the E/A ratio (1.17+/-0.16 vs. 1.33+/-0.19; P<0.001). Conversely, no change was observed in group II. CONCLUSIONS: An impairment of left ventricular diastolic function, which may be reversible with T4 therapy, was observed in the SHT patients, and IMP may be useful in the evaluation of LV myocardial dysfunction in these patients.

Adult↗

PubMed2005

Multivariate source prelocalization (MSP): use of functionally informed basis functions for better conditioning the MEG inverse problem.

Spatially characterizing and quantifying the brain electromagnetic response using MEG/EEG data still remains a critical issue since it requires solving an ill-posed inverse problem that does not admit a unique solution. To overcome this lack of uniqueness, inverse methods have to introduce prior information about the solution. Most existing approaches are directly based upon extrinsic anatomical and functional priors and usually attempt at simultaneously localizing and quantifying brain activity. By contrast, this paper deals with a preprocessing tool which aims at better conditioning the source reconstruction process, by relying only upon intrinsic knowledge (a forward model and the MEG/EEG data itself) and focusing on the key issue of localization. Based on a discrete and realistic anatomical description of the cortex, we first define functionally Informed Basis Functions (fIBF) that are subject specific. We then propose a multivariate method which exploits these fIBF to calculate a probability-like coefficient of activation associated with each dipolar source of the model. This estimated distribution of activation coefficients may then be used as an intrinsic functional prior, either by taking these quantities into account in a subsequent inverse method, or by thresholding the set of probabilities in order to reduce the dimension of the solution space. These two ways of constraining the source reconstruction process may naturally be coupled. We successively describe the proposed Multivariate Source Prelocalization (MSP) approach and illustrate its performance on both simulated and real MEG data. Finally, the better conditioning induced by the MSP process in a classical regularization scheme is extensively and quantitatively evaluated.

Algorithms↗

PubMed2006

Partial correlation for functional brain interactivity investigation in functional MRI.

Examination of functional interactions through effective connectivity requires the determination of three distinct levels of information: (1) the regions involved in the process and forming the spatial support of the network, (2) the presence or absence of interactions between each pair of regions, and (3) the directionality of the existing interactions. While many methods exist to select regions (Step 1), very little is available to complete Step 2. The two main methods developed so far, structural equation modeling (SEM) and dynamical causal modeling (DCM), usually require precise prior information to be used, while such information is sometimes lacking. Assuming that Step 1 was successfully completed, we here propose a data-driven method to deal with Step 2 and extract functional interactions from fMRI datasets through partial correlations. Partial correlation is more closely related to effective connectivity than marginal correlation and provides a convenient graphical representation for functional interactions. As an instance of brain interactivity investigation, we consider how simple hand movements are processed by the bihemispheric cortical motor network. In the proposed framework, Bayesian analysis makes it possible to estimate and test the partial statistical dependencies between regions without any prior model on the underlying functional interactions. We demonstrate the interest of this approach on real data.

Cerebral Cortex↗

PubMed2004

Experimental parkinsonism alters anandamide precursor synthesis, and functional deficits are improved by AM404: a modulator of endocannabinoid function.

Modulation of the endocannabinoid system might be useful in treating Parkinson's disease. Here, we show that systemic administration of N-(4-hydroxyphenyl)-arachidonamide (AM404), a cannabinoid modulator that enhances anandamide (AEA) availability in the biophase, exerts antiparkinsonian effects in 6-hydroxydopamine-lesioned rats. Local injections of AM404 into denervated striata reduced parkinsonian motor asymmetries, these effects being associated with the reduction of D2 dopamine receptor function together with a positive modulation of 5-HT(1B) serotonin receptor function. Stimulation of striatal 5-HT(1B) receptors alone was observed to ameliorate parkinsonian deficits, supporting the fact that AM404 exerts antiparkinsonian effects likely through stimulation of striatal 5-HT(1B) serotonin receptor function. Hence, modulation of cannabinoid function leading to enhancement of AEA in the biophase might be of therapeutic value in the control of symptoms of Parkinson's disease. On the other hand, reduced levels of N-acyl-transferase (AEA precursor synthesizing enzyme), without changes in fatty acid amidohydrolase (AEA degradative enzyme), were detected in denervated striata in comparison with intact striata. This finding reveals the presence of a homeostatic striatal mechanism emerging after dopaminergic denervation likely tending to enhance low dopamine tone.

Acyltransferases↗

PubMed2001

The effects of ropivacaine hydrochloride on platelet function: an assessment using the platelet function analyser (PFA-100).

Amide local anaesthetics impair blood clotting in a concentration-dependent manner by inhibition of platelet function and enhanced fibrinolysis. We hypothesised that the presence of ropivacaine in the epidural space could decrease the efficacy of an epidural blood patch, as this technique requires that the injected blood can clot in order to be effective. Ropivacaine is an aminoamide local anaesthetic used increasingly for epidural analgesia during labour. The concentration of local anaesthetic in blood achieved in the epidural space during the performance of an epidural blood patch is likely to be the greatest which occurs (intentionally) in any clinical setting. This study was undertaken to investigate whether concentrations of ropivacaine in blood, which could occur: (i) clinically in the epidural space and (ii) in plasma during an epidural infusion of ropivacaine, alter platelet function. A platelet function analyser (Dade PFA-100, Miami) was employed to assess the effects of ropivacaine-treated blood on platelet function. The greater concentrations of ropivacaine studied (3.75 and 1.88 mg x ml(-1)), which correspond to those which could occur in the epidural space, produced significant inhibition of platelet aggregation. We conclude that the presence of ropivacaine in the epidural space may decrease the efficacy of an early or prophylactic epidural blood patch.

Adult↗

PubMed1999

ACE inhibition with ramipril improves left ventricular function at rest and post exercise in patients with stable ischaemic heart disease and preserved left ventricular systolic function.

AIMS: To assess the effects of 6 months intervention with +ramipril on resting and post exercise left ventricular function in patients with stable ischaemic heart disease and preserved left ventricular systolic function. METHODS AND RESULTS: Patients (n=98, age 65+/-9 years, 37% women) were randomized to double-blind treatment with ramipril 5 mg. day(-1)(n=32), ramipril 1.25 mg. day(-1)(n=34), or placebo (n=32). Resting and post maximum exercise echocardiography/Doppler examinations were performed at baseline and after 6 months. Changes over 6 months in resting transmitral E-wave deceleration time (Edt) and Edt adjusted for heart rate (Edt/RR) differed between the ramipril 5 mg, ramipril 1.25 mg, and placebo groups: Edt 24+/-82, -1+/-69, and -29+/-64 ms, respectively, P=0. 012; Edt/RR 30+/-105, 2+/-61, and -28+/-69 ms, respectively, P=0.015. Changes in the difference between resting and post exercise Edt/RR also varied between groups: -53+/-137, -28+/-118, and 35+/-101 ms, respectively, P=0.029. No differences in E/A indices were noted. Resting atrioventricular plane displacement improved in the combined ramipril groups vs the placebo group: 0.2+/-0.8 vs -0.2+/-1.3 mm, P<0.05.Conclusion Six months ramipril treatment in patients with stable ischaemic heart disease and preserved left ventricular systolic function improved resting left ventricular function and reduced the exercise induced diastolic filling abnormalities usually seen in these patients.

Aged↗

PubMed1992

[The effect of acute cellular rejection on liver function following orthoptic liver transplantation. Quantitative functional studies with the 14C-aminopyrine breath test].

To test the effect of acute cellular rejection on liver function as represented by cytochrome-P-450 enzyme activity, the 14C-aminopyrine breath test (ABT) was performed prospectively in 46 patients (31 men, 15 women; mean age 48 [15-66] years) who had undergone a total of 50 orthotopic liver transplantations. Routine biochemical tests were performed daily until the 30th postoperative day, while the ABT was done daily on days 1-10 and three times weekly on days 11-30, and liver puncture biopsies were obtained once weekly or more often if there was clinical suspicion of rejection. Histologically confirmed cellular rejection occurred within the stated period of observation in eight patients (five women, three men; median age 45 [18-59] years). Results of routine laboratory tests (transaminases, bilirubin, thromboplastin time), as well as bile-flow and body temperature, did not vary uniformly. On the other hand, results of ABT at the time of rejection showed a decrease in all patients by an average of 65% (P < 0.01). Changes in the ABT preceded those in other tests by 1-2 days in four patients, being the only measurable functional abnormality in one. All rejection episodes responded to glucocorticoid pulse-treatment (three times 1 g methyl-prednisolone). Using ABT results as criterion, liver function became normal after the glucocorticoid injection within 4-11 days. These data indicate that the ABT is suitable in the routine monitoring of transplant function, thus facilitating early diagnosis and controlled treatment of acute cellular rejection.

Acute Disease↗

PubMed2003

Exploring developmental change in the neural bases of higher cognitive functions: the promise of functional magnetic resonance imaging.

The dramatic changes in cognitive ability observed throughout childhood mirror comparably significant changes in the developing brain. Studies of animals provide important data on associations between the development of behavior and the neural substrate. However, understanding the development of brain-behavior relations for higher cognitive functions in humans requires direct, concurrent measurement of behavior and brain functions in the children themselves. To date, such data have been very limited. Recent developments in functional magnetic resonance imaging (fMRI) provide the opportunity to systematically explore the development of brain-behavior relations in children. In this article we consider the potential of fMRI to contribute to researchers' understanding of the development of brain-behavior relations. We begin with an overview of the basic imaging method. We then review work from our own laboratory that demonstrates systematic patterns of association between performance on visuospatial tasks and patterns of brain activation, and we compare our findings with those from other laboratories focused on other cognitive domains. Finally, we discuss the potential impact of functional imaging on researchers' understanding of core issues in cognitive and brain development.

Adolescent↗

PubMedDate not supplied

Assessment of renal function in renal transplant patients using cystatin C. A comparison to other renal function markers and estimates.

To date, little evidence is available to define the role of cystatin C in patients with renal transplants. Thus, to assess, whether cystatin C (CysC) provides better information on renal function than other markers, CysC, creatinine clearance (CrCl), serum creatinine (SCr), beta2-microglobulin (beta2-M), and 125I-Iothalamate clearance were determined in 30 patients. Correlation and ROC curves were obtained and characteristics like sensitivity and specificity were calculated. Further, to evaluate the usefulness of these markers for monitoring, intraindividual coefficients of variation for CysC and SCr measurements were compared in 85 renal transplant patients. CysC correlated best with GFR, whereas SCr, CrCl and beta2-M all had lower correlation coefficients. CysC was superior to SCr, even when renal function equations of were used. The diagnostic accuracy of CysC was significantly better than SCr. but did not differ significantly from CrCl and beta2-M. Together, our data show that in patients with renal transplants, CysC has a similar diagnostic value as CrCl. However, it is superior to determinations of SCr. The intraindividual variation of CysC is significantly greater than that of SCr. This might be due to better ability of CysC to reflect temporary changes especially in mildly impaired GFR, most critical for early detection of rejection and other function impairment. In conclusion, CysC allows for easy and accurate assessment of renal function (GFR) in steady state renal transplant patients and is clearly superior to the commonly used serum creatinine.

Adult↗