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PubMed2000

Correlation of changes in quality of life after lung volume reduction surgery with changes in lung function, exercise, and gas exchange.

STUDY OBJECTIVES: To evaluate correlations between improvement in quality of life (QOL) in patients with severe COPD before and after they undergo lung volume reduction surgery (LVRS) with changes in pulmonary function tests, gas exchange, exercise performance, and alterations in medical management. DESIGN: Case-series analysis. SETTING: University hospital. PATIENTS: Forty-two patients (mean [+/- SD] age, 56+/-8 years; 53% women) with severe airflow obstruction (FEV(1), 0.62+/-0.2 L), and moderate to severe hyperinflation (total lung capacity [TLC], 6.9+/-1.7 L). INTERVENTION AND MEASUREMENTS: All patients underwent bilateral LVRS via median sternotomy. Measurements of lung function, symptom-limited cardiopulmonary exercise testing, the total distance the patient was able to walk in 6 min in a corridor, and sickness impact profile (SIP) scores were made before and 3 months after LVRS. SIP scores are inversely proportional to the level of function and QOL. RESULTS: Compared to baseline, FEV(1) increased (0.87+/-0.3 vs. 0.62+/-0.2 L, respectively; p<0.01) while residual volume significantly decreased (3.2+/-1.8 vs. 6.3+/-1.2 L, respectively; p<0.004) at 3 months post-LVRS. On cardiopulmonary exercise testing, values increased from baseline to post-LVRS for total exercise time (9.0+/-2.2 vs. 6.0+/-1.5 min, respectively; p = 0.045), maximum oxygen uptake (VO(2)) (16+/-3 vs. 11+/-2 mL/kg/min, respectively; p = 0.01), and maximum minute ventilation (VE) (33+/-9 vs. 28+/-5 L/min, respectively; p = 0.03). The percentage change in the oxygen cost of breathing (VO2/VE ratio) from low to high workloads during exercise was significantly lower after LVRS (p = 0.002). There was no significant change in oxygenation after LVRS (PaO(2)/fraction of inspired oxygen, 331+/-27 vs. 337+/-39, respectively; p = 0.76), but PaCO(2) tended to be lower (41+/-9 vs. 48+/-6 mm Hg, respectively; p = 0.07). Overall SIP scores were significantly lower after LVRS than before (8+/-4 vs. 15+/-2, respectively; p = 0.002). Changes in SIP scores correlated with the change in VO2/VE ratio from low to high workloads, with patients having the smallest changes in VO2/VE ratio having the smallest changes in SIP scores after LVRS (r = 0.6; p = 0.01). Improved or lower SIP scores also tended to correlate with a reduction in residual volume/TLC ratio (r = 0.45; p = 0.09), and there was a linear correlation with a statistically significant Pearson r value with decreased steroid requirements (r = 0.7; p = 0.001). Moreover, changes in psychological SIP subscore tended to correlate with diminished oxygen requirements post-LVRS (r = 0.45; p = 0.09). However, there was no significant correlation between changes in SIP scores and routine measurements of lung function, exercise performance, or gas exchange. CONCLUSION: There is an association between an improvement in QOL and reduced hyperinflation after LVRS. Reduced hyperinflation may lead to more efficient work of breathing during exercise and, therefore, to an increased ability to perform daily activities. Changes in QOL scores correlate best with behaviorally based variables that directly affect the patient's well-being, such as systemic steroid administration.

Case-Control Studies↗

PubMedDate not supplied

Correlation among markers of renal osteodystrophy in pediatric hemodialysis patients.

Serum levels of parathyroid hormone (PTH), alkaline phosphatase (AP), and calcium (Ca2+) have been used to evaluate renal osteodystrophy (RO) in adult patients undergoing dialysis. Osteocalcin (BGP) is a bone protein which also serves as a marker for bone turnover. Serum BGP levels correlate positively with rates of bone turnover and serum concentrations of PTH, AP, and Ca2+ in various studies of adult end-stage renal disease (ESRD) patients, whereas other studies reveal BGP to be a poor indicator of bone turnover in ESRD. RO is a significant problem in pediatric ESRD patients; however, there have been few studies evaluating the correlation of markers for RO in children with ESRD. We measured serum PTH, AP, Ca2+, and BGP levels in a group (n=23) of pediatric patients with ESRD and assessed the correlation among the markers. There was a positive correlation between serum PTH and AP (r=0.658, p<0.001). In contrast, there was no correlation between either serum Ca2+ or BGP, and either PTH or AP. The correlation between Ca2+, BGP and either PTH or AP was unaffected by growth in our patient population. Finally, neither age nor pubertal stage improved the correlation between either Ca2+ or BGP, and either PTH or AP. We conclude that serum PTH and AP are useful markers for RO, whereas calcium and BGP levels should not be used to evaluate RO in pediatric ESRD patients.

Adolescent↗

PubMed2005

Dynamically modulated spike correlation in monkey inferior temporal cortex depending on the feature configuration within a whole object.

The mechanism underlying the processing of spatially separated multiple local features to form a unique whole object is an important issue in visual object recognition. We tested whether, in behaving monkeys, the spike correlation between pairs of inferior temporal (IT) neurons dynamically changes depending on the spatial configuration of the local features within a whole object. We prepared more than 60,000 face-like objects (FOs) and their corresponding non-face-like objects (NFOs) that consisted of random arrangements of the same set of local features as those in FOs. The spike correlation between a pair of neurons was quantified by the peak height of the shift predictor-subtracted cross-correlogram. For both neurons of the pair, the local features in a whole object were determined so that they elicited as high a response as possible to enable a reliable cross-correlation analysis. We found that the FOs thus constructed elicited neuronal activities that were more strongly correlated than the corresponding NFOs. Firing rates of the same neurons did not show such a consistent bias depending on the feature configuration. Furthermore, receiver operating characteristic analysis revealed that this FO dominance of spike correlation was robust enough to discriminate between different feature configurations at the population level. Spike correlation of the cell pairs exhibited significant FO dominance within 300 ms after stimulus onset. The present results suggest that feature configuration within a unique whole object can be reflected in the rapid modulation of spike correlation among a population of neurons in the IT cortex.

Action Potentials↗

PubMed2005

Spatiotemporal image correlation spectroscopy (STICS) theory, verification, and application to protein velocity mapping in living CHO cells.

We introduce a new extension of image correlation spectroscopy (ICS) and image cross-correlation spectroscopy (ICCS) that relies on complete analysis of both the temporal and spatial correlation lags for intensity fluctuations from a laser-scanning microscopy image series. This new approach allows measurement of both diffusion coefficients and velocity vectors (magnitude and direction) for fluorescently labeled membrane proteins in living cells through monitoring of the time evolution of the full space-time correlation function. By using filtering in Fourier space to remove frequencies associated with immobile components, we are able to measure the protein transport even in the presence of a large fraction (>90%) of immobile species. We present the background theory, computer simulations, and analysis of measurements on fluorescent microspheres to demonstrate proof of principle, capabilities, and limitations of the method. We demonstrate mapping of flow vectors for mixed samples containing fluorescent microspheres with different emission wavelengths using space time image cross-correlation. We also present results from two-photon laser-scanning microscopy studies of alpha-actinin/enhanced green fluorescent protein fusion constructs at the basal membrane of living CHO cells. Using space-time image correlation spectroscopy (STICS), we are able to measure protein fluxes with magnitudes of mum/min from retracting lamellar regions and protrusions for adherent cells. We also demonstrate the measurement of correlated directed flows (magnitudes of mum/min) and diffusion of interacting alpha5 integrin/enhanced cyan fluorescent protein and alpha-actinin/enhanced yellow fluorescent protein within living CHO cells. The STICS method permits us to generate complete transport maps of proteins within subregions of the basal membrane even if the protein concentration is too high to perform single particle tracking measurements.

Actinin↗

PubMed2000

Fetal leptin and insulin levels only correlate inlarge-for-gestational age infants.

OBJECTIVE: To determine whether fetal leptin levels correlate with fetal weight and whether such correlation is direct or indirect via insulin or human placental lactogen (hPL), respectively. DESIGN: Cross-sectional study of offspring at term (n=175) with over-representation of large-for-gestational age (LGA; n=70) and small-for-gestational age (SGA; n=23) cases in a population of Caucasian women with no pregnancy pathology. METHODS: Fetal cord blood was collected after delivery. In several cases (n=62) paired mother-fetus blood samples were obtained. Leptin, insulin and hPL levels were measured by RIA. Anthropometric data (birth weight, body mass index, placental weight) were recorded. RESULTS AND CONCLUSIONS: Maternal insulin, hPL and leptin levels were higher than fetal concentrations. Cord blood leptin levels positively correlated with the anthropometric data with stronger correlations in female (0.54<r<0.66) than in male (0.32<r<0.39) neonates. Cord blood leptin levels did not differ between appropriate-for-gestational age (AGA; n=82) and SGA (n=23) neonates, but were higher (P<0.001) by 83% in LGA (n=70) than in AGA neonates. Among the different weight classes the correlations between fetal leptin and anthropometric data were only observed in LGAs, but not in AGAs or SGAs. Fetal, but not maternal, leptin levels strongly correlated with fetal insulin (r=0.56; P<0.001). After accounting for this close relationship insulin could no longer be used to predict birth weight (r=0.15, P=0.051). We suggest that the correlation of cord blood insulin with neonatal weight in LGAs is, in addition to insulin's direct anabolic action, indirectly mediated via leptin. It is hypothesized that fetal insulin stimulates fetal adipocyte leptin production.

Birth Weight↗

PubMed1990

Direct responses in males and correlated responses for reproduction in females to selection for testicular size adjusted for body weight in young male lambs.

Selection based upon testicular diameter adjusted for body weight at 6, 10 and 14 weeks of age was used to produce two lines of sheep, with either high or low testicular size. Ten generations of selection were carried out and the estimate of the realized heritability of the selection criterion was 0.53 +/- 0.01. There were significant positive correlated responses to selection for testicular diameter at 6, 10 and 14 weeks of age, but the correlated responses in body weight at these ages were negative. In mature females, there were significant negative correlated responses to selection in premating body weight in the 1st, 2nd and 3rd breeding season and in the day of the first oestrus in the 2nd breeding season. Litter size per ewe mated had a small positive correlated response to selection in the second breeding season. This latter response appeared to be due to a positive correlated response in fertility, ewes from the High-line having a significantly higher probability of conceiving to a single mating than those from the Low-line. There was no significant correlated response in ovulation rate or litter size per ewe lambing and the genetic correlation between these traits and the selection criterion is likely to be close to zero. This may be due to the adjustment for body weight used, but it is possible that, in any event, body weight in young rams may be a better predictor of female ovulation rate than testicular diameter. These results do not rule out the possibility that testicular size in rams older than those selected would provide a good predictor of genetic merit for female ovulation rate.

Animals↗

PubMed2006

Correlation of mRNA expression and protein abundance affected by multiple sequence features related to translational efficiency in Desulfovibrio vulgaris: a quantitative analysis.

The modest correlation between mRNA expression and protein abundance in large-scale data sets is explained in part by experimental challenges, such as technological limitations, and in part by fundamental biological factors in the transcription and translation processes. Among various factors affecting the mRNA-protein correlation, the roles of biological factors related to translation are poorly understood. In this study, using experimental mRNA expression and protein abundance data collected from Desulfovibrio vulgaris by DNA microarray and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) proteomic analysis, we quantitatively examined the effects of several translational-efficiency-related sequence features on mRNA-protein correlation. Three classes of sequence features were investigated according to different translational stages: (i) initiation, Shine-Dalgarno sequences, start codon identity, and start codon context; (ii) elongation, codon usage and amino acid usage; and (iii) termination, stop codon identity and stop codon context. Surprisingly, although it is widely accepted that translation initiation is the rate-limiting step for translation, our results showed that the mRNA-protein correlation was affected the most by the features at elongation stages, i.e., codon usage and amino acid composition (5.3-15.7% and 5.8-11.9% of the total variation of mRNA-protein correlation, respectively), followed by stop codon context and the Shine-Dalgarno sequence (3.7-5.1% and 1.9-3.8%, respectively). Taken together, all sequence features contributed to 15.2-26.2% of the total variation of mRNA-protein correlation. This study provides the first comprehensive quantitative analysis of the mRNA-protein correlation in bacterial D. vulgaris and adds new insights into the relative importance of various sequence features in prokaryotic protein translation.

Bacterial Proteins↗

PubMed1975

Correlation between pulmonary vascular resistance and pulmonary arterial diastolic pressure in congenital heart diseases with left to right shunt.

Our studies recently conducted on the correlation between pulmonary vascular resistance and pulmonary arterial diastolic pressure in 467 cases, identified an extremely high correlation between the two. The correlation coefficient between pulmonary arterial diastolic pressure (PAdp) and pulmonary to systemic resistance ratio (Rp/Rs) was 0.799 and that between pulmonary vascular resistance index (RP-index) and PAdp was found to be 0.791. And a still higher correlation was observed between pulmonary vascular resistance and pressure gradient between PAdp and left atrial mean pressure (LAmp), where the correlation coefficient between Rp/Rs and (PAdp-LAmp) was 0.851 and that between Rp-index and (PAdp-LAmp) was 0.813. Those correlations are found to be higher in degree than the correlations between pulmonary arterial mean pressure or pulmonary arterial systolic pressure and pulmonary vascular resistance, leading to the conclusion that the pulmonary arterial diastolic pressure is of extremely high clinical importance as an index for increase in pulmonary vascular resistance.

Adolescent↗

PubMed2004

Positive correlation of serum leptin with estradiol levels in patients with polycystic ovary syndrome.

Patients with polycystic ovary syndrome (PCOS) usually are obese, insulin resistant and hyperinsulinemic. The known association between leptin, obesity and insulin action suggests that leptin may have a role in PCOS but this has only been addressed peripherally. This study was designed to assess the relationship between serum leptin and the anthropometric, metabolic and endocrine variables of obese (body mass index, BMI (3)30 kg/m(2)) and non-obese (BMI <30 kg/m(2)) PCOS patients. Twenty-eight PCOS patients and 24 control women subdivided into obese and non-obese groups were evaluated. Leptin, androgens, lipids, gonadotrophins and insulin-glucose response to the oral glucose tolerance test were measured by radioimmunoassay in all participants. The assays were done all in one time. The areas under the insulin curve (AUC-I) and the glycemia curve were calculated to identify patients with insulin resistance. Mean leptin levels were not significantly higher in patients with PCOS compared to the control group (21.2 +/- 10.2 vs 27.3 +/- 12.4 ng/ml). Leptin levels were found to be significantly higher in the obese subgroups both in patients with PCOS (26.9 +/- 9.3 vs 14.1 +/- 7.0 ng/ml) and in the control group (37.3 +/- 15.5 vs 12.9 +/- 5.8 ng/ml). The leptin of the PCOS group was correlated with BMI (r = 0.74; P < 0.0001) and estradiol (r = 0.48; P < 0.008) and tended to be correlated with the AUC-I (r = 0.36; P = 0.05). Of the parameters which showed a correlation with leptin in PCOS, only estradiol and probably insulinemia (AUC-I) did not show a significant correlation with BMI, suggesting that the other parameters were correlated with leptin due to their correlation with BMI. Estradiol correlated with leptin in PCOS patients regardless of their weight.

Adolescent↗

PubMed2006

Lack of in vivo correlation between indinavir and saquinavir exposure and cytochrome P450 3A phenotype as assessed with oral midazolam as a phenotype probe.

STUDY OBJECTIVE: To investigate a potential correlation between exposure to oral midazolam, a commonly used cytochrome P450 (CYP) 3A probe, and saquinavir and indinavir exposure. DESIGN: Open-label, prospective, pharmacokinetic study. SETTING: Outpatient research center. SUBJECTS: Thirty-six healthy volunteers aged 22-50 years. INTERVENTION: Subjects received a single oral dose of midazolam 8 mg; 4 hours later, blood was drawn to determine their serum midazolam concentrations. Midazolam phenotyping was followed by successive administration of the protease inhibitors indinavir and saquinavir, with blood sampling and pharmacokinetic analyses performed at steady state. MEASUREMENTS AND MAIN RESULTS: Pharmacokinetic parameters of each protease inhibitor were evaluated to assess for a potential relationship with 4-hour concentrations of midazolam. No correlations between phenotype results for midazolam and any pharmacokinetic parameter for indinavir or saquinavir were identified (r(2)=0.00002-0.073). When the results were analyzed based on race, significant correlations were identified in five African-American subjects, including correlations between 4-hour midazolam levels and apparent oral clearance of saquinavir (r(2)=0.734, p=0.064), area under the plasma concentration-time curve from 0-8 hours (r(2)=0.914, p=0.011), minimum concentration (r(2)=0.857, p=0.024), and maximum concentration (r(2)=0.969, p=0.002). These findings for African-American subjects were not seen with indinavir. No correlation was found between indinavir and saquinavir pharmacokinetic parameters (r(2)=0.017-0.261). CONCLUSION: Oral midazolam was not a useful probe for predicting saquinavir or indinavir exposure at steady state. Reasons for the lack of correlation likely included differences between midazolam and protease inhibitor P-glycoprotein specificity, differences in the relative contribution of CYP3A5-mediated metabolism, and/or variation in intestinal and hepatic CYP3A specificity. The strong correlation between midazolam phenotype and pharmacokinetic parameters for saquinavir in African-American subjects indicated a racial difference in one or more of these confounding variables.

Administration, Oral↗

PubMed2002

The correlation between nasalance and a differentiated perceptual rating of speech in Dutch patients with velopharyngeal insufficiency.

OBJECTIVE: The correlation between the nasalance score and the perceptual rating of several aspects of speech of speakers with velopharyngeal insufficiency (VPI) by six speech-language pathologists was evaluated. PROCEDURE: The overall grade of severity, hypernasality, audible nasal emission, misarticulations, and intelligibility were rated on visual analog scales. Speech samples with a normal distribution of phonemes (normal text [NT]) and those free of nasal consonants (denasal text [DT]) of 43 patients with VPI were used. Mean nasalance scores were computed for the speech samples, and Spearman correlation coefficients were computed between the mean nasalance score and the five parameters of the differentiated rating. SETTING: The Institute of Phoniatrics, Utrecht University Hospital, The Netherlands. RESULTS: The correlation coefficient between the mean nasalance and the perceptual rating of hypernasality ranged among judges from .31 to .56 for NT speech samples and .36 to .60 for DT speech samples. Only small differences were found between speech pathologists with and without expertise in cleft palate speech. The rating of the overall grade of severity appeared to correlate quite well with the rating of the intelligibility (r(NT) = .77, r(DT) = .79). Lower correlation coefficients, ranging from .34 to .71, were found between overall grade of severity and hypernasality, audible nasal emission, and misarticulations. CONCLUSIONS: A low correlation between the nasalance and the perceptual rating of hypernasality was found. The parameter overall grade of severity appeared to be determined mainly by the parameter intelligibility. Expertise in rating of cleft palate speech does not guarantee a high correlation between instrumental measurement and perceptual rating.

Adolescent↗

PubMed2002

Negative correlations between resistance to three organophosphate insecticides and productivity within a natural population of Drosophila melanogaster (Diptera: Drosophilidae).

To investigate the relationship between resistance to organophosphate insecticides and fitness components, we first measured resistance to three organophosphates, malathion, prothiophos, and fenitrothion, and productivity, a measure of fitness components, for each of the isofemale lines from the same natural population of Drosophila melanogaster (Meigen). Pearson correlation coefficients indicated that positive correlations among resistance to the organophosphates and negative correlations between resistance to each of the organophosphates and the productivity existed within the natural population. We further investigated the genetic basis of the correlations among resistance to the organophosphates and the productivity, by using chromosome-substituted lines between a resistant and a susceptible inbred line established from the same natural population. Chromosomal analyses indicated that the third chromosome from the resistant line exhibited not only significant, positive effects on resistance to all of the organophosphates tested but also a significant negative effect on the productivity, suggesting positive genetic correlations between resistance to each organophosphate and negative genetic correlations between resistance to each organophosphate and the productivity. In addition, a significant negative effect on the productivity was also detected from the second chromosome, which did not exhibit significant major effects on resistance to the organophosphates. This suggests that fitness components of resistant lines could be also affected by factors independent of insecticide resistance. The dynamics of genetic variation in resistance to the organophosphates within the natural population of D. melanogaster are discussed from the standpoint of negative genetic correlations between resistance to the organophosphates and the productivity.

Animals↗

PubMed1967

Some effects of correlation between response-contingent shock and reinforcement.

Rats responded on a two-component chain schedule in which a response-contingent electric shock at the end of the first component was either positively correlated, negatively correlated, or uncorrelated with reinforcement availability in the second component. With 0.4-ma shocks, rate in the first component depended on the shock-reinforcement correlation: when shock and reinforcement availability were positively correlated, after extended exposure to the contingencies, rates exceeded those in the absence of shock; when shock and reinforcement availability were negatively correlated, responding was generally suppressed throughout. The discriminative control of shock over responding in the second component, in which reinforcement was available 50% of the time, also depended somewhat on correlation. However, rate change in the first component was not specifically related to discrimination in the second component. With 0.8-ma shocks, responding was substantially suppressed in the first component at all three values of shock-reinforcement correlations.

Animals↗

PubMed1987

Cross-correlation analysis of neuronal activities.

Nerve impulses are generally regarded as spike train and analyzed by use of various kinds of so-called time series analyses. Cross-correlation analysis is used to reveal temporal and/or spatial relationships between more than two spike trains in the neuronal circuit, in which two neurons are synaptically connected or two neurons are independent but receive a common input. Three main characteristics of discharge dependency between two neurons become clear from the cross-correlation histogram: 1) the direction of dependency; 2) the latency of interaction; and 3) the type of functional connections between the neurons. We reviewed the cross-correlation analysis from these points of view: 1) what is cross-correlation analysis; 2) what are primary and secondary effects; 3) what kinds of functional information can be obtained from the shape of the primary effect; 4) how sensitively cross-correlation can detect neuronal interaction; 5) how to express quantitatively the primary effect; 6) what kinds of extension technique are available from cross-correlation; and 7) research trends using cross-correlation analysis.

Animals↗

PubMed2006

Renal interlobar artery parameters with duplex Doppler sonography and correlations with age, plasma renin, and aldosterone levels in healthy children.

OBJECTIVE: The objectives of this study were to compare and make correlations between age and Doppler parameters of the interlobar arteries, including synchronously obtained plasma renin and aldosterone levels and to obtain new normative data regarding acceleration time in healthy children from neonates to 16 years. SUBJECTS AND METHODS: One hundred sixty-nine healthy children (72 girls and 97 boys) were classified into four groups: group 1 (< 1 year; n = 34), group 2 (range, 1-6 years; n = 48), group 3 (range, 6-12 years; n = 50), and group 4 (range, 12-16 years; n = 37). Blood samples from the renin and aldosterone were collected in the morning after bed rest and fasting. The resistive index (RI), pulsatility index (PI), and the acceleration time of the renal interlobar arteries with duplex Doppler sonography, including both kidney longitudinal lengths with grayscale sonography, were evaluated. One-way analysis of variance with the least significant difference post-hoc test and Pearson's correlation test were used to compare the differences between groups and to make correlations, respectively. An independent-sample t test was used to evaluate the differences between all parameters based on sex and to compare the left and right kidney longitudinal lengths in each group. RESULTS: The RI, PI, and acceleration time were statistically significant in between-group comparisons. Only in group 4 was acceleration time not statistically significant compared with groups 2 and 3. Plasma renin levels were significantly higher in group 1 compared with groups 2 (p < 0.03) and 4 (p < 0.0001); in group 2 compared with group 4 (p < 0.05); and in group 3 compared with group 4 (p < 0.01). The plasma aldosterone levels were significantly higher only in group 1 compared with groups 2 (p < 0.001), 3 (p < 0.008), and 4 (p < 0.0001). The RI correlated linearly with the PI, plasma renin levels, and aldosterone levels and correlated inversely with acceleration time. Age had a negative correlation with the RI, PI, plasma renin levels, and aldosterone levels and correlated positively with acceleration time. There were no statistically significant differences between all parameters based on sex and no significant difference found between the right and left kidney longitudinal lengths in each group. CONCLUSION: The RI in children up to 54 months old is higher than in adults. Therefore, the adult mean renal RI criterion of 0.70 should be applicable to children 54 months old and older. We showed that the age dependency of the RI was directly related to that of plasma renin and aldosterone levels in healthy children in whom Doppler parameters and blood analysis were evaluated synchronously.

Adolescent↗

PubMed1997

High-resolution CT in the acute exacerbation of cystic fibrosis: evaluation of acute findings, reversibility of those findings, and clinical correlation.

OBJECTIVE: The aims of this study were threefold: to compare high-resolution CT (HRCT) of adult patients with cystic fibrosis (CF) during acute exacerbations with asymptomatic patients with CF, to evaluate reversibility of HRCT abnormalities after exacerbations, and to correlate HRCT with clinical parameters. SUBJECTS AND METHODS: Nineteen symptomatic and eight asymptomatic patients were prospectively evaluated by HRCT and pulmonary function tests (PFTs). Symptomatic patients were reassessed 2 weeks after the exacerbation. Studies were independently reviewed by two radiologists using a modified Bhalla scoring system, noting the presence, extent, and severity of bronchiectasis, peribronchial thickening, mucus plugging, and atelectasis or consolidation. Modifications to the Bhalla system included evaluation of the presence and profusion of centrilobular nodules and air-fluid levels within bronchiectatic cavities. The highest possible score was 24 points. Higher scores indicated greater severity. Mosaic perfusion was noted but not included in the modified Bhalla HRCT score. Total modified Bhalla HRCT score and components of the HRCT score were correlated with corresponding PFT parameters. RESULTS: Bronchiectasis, peribronchial thickening, mucus plugging, centrilobular nodules, and mosaic perfusion were identified in symptomatic and asymptomatic patients. Air-fluid levels in bronchiectatic cavities, identified in two patients, represented the only finding limited to acute exacerbation. Reversible findings included air-fluid levels (100%), centrilobular nodules (36%), mucus plugging (33%), and peribronchial thickening (11%). Total HRCT severity scores of symptomatic and asymptomatic patients correlated with forced vital capacity (FVC) (r = .44, p = .01) and forced expiratory volume at 1 sec (FEV1) (r = .34, p = .04). Severity of bronchiectasis correlated with FVC (r = .50, p = .004) and FEV1 (r = .40, p = .02). Mucus plugging and centrilobular nodules did not correlate with PFT parameters. In the symptomatic patients, improvement in HRCT score correlated with changes in FEV1/FVC (r = .39, p = .049). CONCLUSION: Air-fluid levels in bronchiectatic cavities were the only parenchymal finding shown by HRCT that was limited to the acute exacerbation of CF in our study population. However, this finding was rare, being seen in two of 19 patients. Mucus plugging, centrilobular nodules, and peribronchial thickening were potentially reversible findings in symptomatic patients. HRCT accurately revealed disease severity in patients with CF. We also found that changes in HRCT scores correlated with clinical improvement as determined by PFTs.

Acute Disease↗

PubMed1998

Correlation of dynamic contrast-enhanced MR imaging with histologic tumor grade: comparison of macromolecular and small-molecular contrast media.

OBJECTIVE: The endothelial integrity of microvessels is disrupted in malignant tumors. Quantitative assays of tumor microvascular characteristics based on dynamic MR imaging were correlated with histopathologic grade in mammary soft-tissue tumors. MATERIALS AND METHODS: A spectrum of tumors, benign through highly malignant, was induced in 33 female rats by administration of N-ethyl-N-nitrosourea, a potent carcinogen. Dynamic contrast-enhanced MR imaging was performed using a small-molecular contrast medium (gadopentetate, molecular weight = 0.5 kDa) and a macromolecular contrast medium (albumin-(Gd-DTPA)30, molecular weight = 92 kDa) at an interval of 1-2 days. Permeability surface area product (PS), as estimated by the corresponding endothelial transfer coefficient (K(PS)), and fractional plasma volume (fPV) were calculated for each tumor and each contrast agent using a two-compartment bidirectional kinetic model. MR imaging microvascular characteristics were correlated with histopathologic tumor grade. RESULTS: Tumor permeability to macromolecular contrast medium, characterized by K(PS), showed a highly positive correlation with tumor grade (r2 = .76, p < 10(-10)). K(PS) values were zero for all benign and some low-grade carcinomas, greater than zero in all other carcinomas, and increased in magnitude with higher tumor grade. A considerably smaller but significantly positive correlation was found between fPV and tumor grade using macromolecular contrast medium (r2 = .25, p < .003). No correlation between K(PS) or fPV values and tumor grade was found using gadopentetate (r2 = .01, p > .95 and r2 = .03, p > .15, respectively). CONCLUSION: Quantitative tumor microvascular permeability assays generated with macromolecular MR imaging contrast medium correlate closely with histologic tumor grade. No significant correlation is found using small-molecular gadopentetate.

Albumins↗

PubMed2000

Coronary calcium in adults with type 1 diabetes: a stronger correlate of clinical coronary artery disease in men than in women.

We studied the relationship of coronary artery calcification (CAC), a marker of coronary atherosclerosis, with prevalent clinical coronary artery disease (CAD) and established cardiovascular disease (CVD) risk factors in a type 1 diabetic population. At the 10-year follow-up examination of the Pittsburgh Epidemiology of Diabetes Complications (EDC) Study cohort, 302 adults (mean age 38.1 +/- 7.8 years) received electron beam tomography (EBT) scanning of the heart and a clinical examination. Clinical CAD was defined as a confirmed history of myocardial infarction (MI), angiographic stenosis > or =50%, Pittsburgh EDC Study physician-diagnosed angina, or ischemic electrocardiogram (ECG). CAC correlated with most CVD risk factors. CAC had 84 and 71% sensitivity for clinical CAD in men and women, respectively, and 100% sensitivity for MI or obstructive CAD. A CACS cut point of 400 was the most efficient coronary calcium correlate of CAD. In subjects with angina only, CAC sensitivity was 83% in men and 46% in women. In logistic regression, CAC, ECG R-R variation, peripheral vascular disease, and Beck Depression Inventory independently correlated with prevalent CAD in men and overall. Except for CAC, the same variables independently correlated with CAD in women, and age also entered the model. CAC was an independent correlate of MI or obstructive CAD in both sexes and was the strongest independent correlate in men, but CAC was not independently associated with angina and ischemic ECG in either sex. It is concluded that EBT-detected CAC is strongly correlated with CAD in type 1 diabetes-particularly in men.

Adult↗