PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “correlation”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources

High resolution computed tomography in cystic fibrosis: correlation with pulmonary function and assessment of prognostic value.

OBJECTIVE: To assess the correlation between HRCT and pulmonary function in patients with CF. Further, to assess the prognostic value of HRCT in these patients. SUBJECTS AND METHODS: Clinical examination, chest radiographs and HRCT scans on 30 CF patients with an average age of 17 were scored using established scoring systems. The results were correlated with FEV1 and FVC both at time of CT scanning and after 30 months. Results were also correlated with the clinical progress of the patients over the follow-up period. RESULTS: HRCT, chest radiograph and clinical examination demonstrated similar correlation (p < 0.001) with FEV1 and FVC at the time of scanning. HRCT demonstrated the closest correlation with the clinical progress of the patients over the follow-up period and with follow-up pulmonary function. A maximum combined score for bronchiectasis and emphysema on HRCT seemed to indicate a poor prognosis. CONCLUSION: HRCT in CF patients correlates well with pulmonary function at time of scanning and at follow-up, and with clinical progress. There may be a role for CT in the identification of adolescent/adult patients who can be expected to need aggressive therapy in the future.

Adolescent↗

Lack of correlation between Tc-99m-sestaMIBI uptake and cadherin expression in infiltrating ductal breast carcinoma as prognostic indicators.

Despite using various kinds of prognostic indicators, it is still not possible to predict the biological behavior of breast cancer in all patients. Tc-99m-sestaMIBI (MIBI) uptake determined by breast scintigraphy and cadherin expression of tumor tissue revealed by immunohistochemistry are suggested as potential agents for this purpose. We hypothesize that there can be a correlation between MIBI whose cellular mitochondrial content is claimed to play a significant role in its tumor uptake and cadherin whose downregulation causes an increase in mitochondrial activity in human mammary carcinoma cell lines. The aim of this study was to assess the relationship between the degree of MIBI tumor uptake and cadherin expression in infiltrating ductal breast carcinoma. Correlation with response to chemotherapy and some known prognostic factors of breast cancer such as tumor size, number of metastatic axillary lymph nodes and microscopic grading was also done. Fourteen patients who underwent scintimammography and subsequent surgical excisional biopsy that revealed infiltrating ductal carcinoma were enrolled in this study. Statistical analysis did not show any correlation between MIBI uptake and cadherin expression (p > 0.05). Also, no statistically significant correlation was noted between MIBI uptake and tumor size, number of metastatic lymph nodes, microscopic grade, stage of the disease or response to chemotherapy. Similarly, there was no statistically significant correlation between cadherin expression and tumor size, number of metastatic lymph nodes, microscopic grade, stage of the disease or chemotherapy response. The results of this study imply that there is no correlation between MIBI tumor uptake and cadherin expression with neither of them good enough to be used as prognostic indicators for breast cancer.

Adult↗

Improving of the accuracy of in vitro-in vivo linear correlation using kinetic models for ultra sustained release theophylline tablets.

The objective of the current study was to establish and evaluate a new technique to increase the accuracy of the in vitro/in vivo linear correlation of single and multiple dose ultra-sustained release theophylline (USRT) preparation (Xantium) in hospitalized patients. In vitro dissolution data for theophylline were collected for 24 h using a USP I (basket) and USP II (paddle) methods. In vivo plasma concentration data were obtained from 8 patients after administration of either single or multiple doses of theophylline. Both in vitro and in vivo results were evaluated by zero-order, first-order, RRSBW, Hixson-Crowell, Higuchi, Hopfenberg, Langenbucher, modified Langenbucher and (Bt)a kinetic models. The individual linear correlations between each in vitro and in vivo percent results and their kinetic distributions were established and regression equations were obtained. The determination coefficient results of the linear kinetic correlations were found to be 0.994 and 0.997 for single and multiple doses by basket method and 0.992 and 0.998 for single and multiple doses by paddle method, respectively. Furthermore, the results of the linear correlations were found as 0.953 and 0.950 for single and multiple doses by basket method and 0.963 and 0.962 for single and multiple doses by paddle method respectively. Therefore, this study suggested that the accuracy of the linear correlation could be improved signilicantly by using linear kinetic correlation.

Adult↗

Fracture prediction by bone density measurements at sites other than the fracture site: the contribution of BMD correlation.

It is widely believed that the most reliable BMD measurement for predicting fracture risk at any given skeletal site is one made at the fracture site itself. This study examines the hypothesis that the ability of BMD measurements at other distant sites in the skeleton remote from the fracture site to predict fracture risk is due to their correlation with the BMD measurements at the fracture site. We refer to this assumption as the correlation hypothesis. We show that the correlation hypothesis predicts the relationship betadist = rbetafrac, where beta is the gradient of the exponential relationship between fracture risk and Z-score, betafrac is the beta-value for the fracture site, betadist the beta-value for the distant BMD site, and r is the correlation coefficient between the Z-scores at the two sites. In practice it is important to consider the effect of BMD measurement errors on the (r, beta) relationship. We show that the effect of errors at the distant site is to reduce betadist and r in a way that preserves their original relationship. When errors at the fracture site are taken into account the effect on the (r, beta) plot is for the point representing the fracture site to fall below the extrapolation of the straight-line relationship predicted for the points representing the distant BMD sites. We tested the correlation hypothesis by using data from the Study of Osteoporotic Fractures to examine the (r, beta) plots for hip, spine and forearm fractures. For the hip the data are consistent with a straight-line relationship and suggest that measurements made at other sites provide no additional information about fracture risk over and above that provided by hip BMD itself. For spine and forearm fractures the data show that distant sites do provide additional information about fracture risk in a way that is quantitatively consistent with the BMD measurement errors reported in cadaver studies. It is clear that random BMD errors at the fracture site cause loss of information about fracture risk and that some of this lost information is recoverable from measurements made at other sites in the skeleton. Overall, this study points to BMD correlation as an important factor in explaining the ability of measurements made at distant sites to predict fracture risk.

Absorptiometry, Photon↗

Correlation of urethral closure pressure, leak-point pressure and incontinence severity measures.

The aim of this study was to determine whether water perfusion maximum urethral closure pressure (MUCP) correlates with Valsalva leak-point pressure (LPP), and which of these best correlates with subjective and objective incontinence severity measures. Fifty-two women with previously diagnosed genuine stress incontinence (n = 46), or mixed incontinence with a minor and controlled urge component (n = 6), were assigned an incontinence status grade based on interview and diary review. These women then completed visually observed standing LPPs at 250 ml bladder capacity, supine water perfusion MUCP determinations, pad tests and quality of life questionnaires. The urodynamic and severity measures were compared with correlation analysis or analysis of variance. A modest correlation exists between LPP and MUCP (r = 0.50-0.62, P < 0.001). Both MUCP and LPP demonstrated significant decreases (P < 0.01) with increasing severity of assigned incontinence grade. A very low and insignificant correlation existed for these urodynamic parameters and pad loss or quality of life measures. MUCP and LPP correlate modestly with each other and both are comparable in predicting incontinence severity. Either can be used as the urodynamic measure to assess intrinsic sphincter deficiency.

Adult↗

Correlation of orofacial speeds with voice acoustic measures in the fluent speech of persons who stutter.

Stuttering is often viewed as a problem in coordinating the movements of different muscle systems involved in speech production. From this perspective, it is logical that efforts be made to quantify and compare the strength of neural coupling between muscle systems in persons who stutter (PS) and those who do not stutter (NS). This problem was addressed by correlating the speeds of different orofacial structures with vowel fundamental frequency (F0) and intensity as subjects produced fluent repetitions of a simple nonsense phrase at habitual, high, and low intensity levels. It is assumed that resulting correlations indirectly reflect the strength of neural coupling between particular orofacial structures and the respiratory-laryngeal system. An electromagnetic system was employed to record movements of the upper lip, lower lip, tongue, and jaw in 43 NS and 39 PS. The acoustic speech signal was recorded and used to obtain measures of vowel F0 and intensity. For each subject, correlation measures were obtained relating peak orofacial speeds to F0 and intensity. Correlations were significantly reduced in PS compared to NS for the lower lip and tongue, although the magnitude of these group differences covaried with the correlation levels relating F0 and intensity. It is suggested that the group difference in correlation pattern reflects a reduced strength of neural coupling of the lower lip and tongue systems to the respiratory-laryngeal system in PS. Consideration is given to how this may contribute to temporal discoordination and stuttering.

Adult↗

Carotid bifurcation calcium and correlation with percent stenosis of the internal carotid artery on CT angiography.

The aim of this paper was to determine the correlation between calcium burden (expressed as a volume) and extent of stenosis of the origin of the internal carotid artery (ICA) by CT angiography (CTA). Previous studies have shown that calcification in the coronary arteries correlates with significant vessel stenosis, and severe calcification (measured by CT) in the carotid siphon correlates with significant (greater than 50% stenosis) as determined angiographically. Sixty-one patients (age range 50-85 years) underwent CT of the neck with intravenous administration of iodinated contrast for a variety of conditions. Images were obtained with a helical multidetector array CT scanner and reviewed on a three-dimensional workstation. A single observer manipulated window and level to segment calcified plaque from vascular enhancement in order to quantify vascular calcium volume (cc) in the region of the bifurcation of the common carotid artery/ICA origin, and to measure the extent of ICA stenosis near the origin. A total of 117 common carotid artery bifurcations were reviewed. A "significant" stenosis was defined arbitrarily as >40% (to detect lesions before they become hemodynamically significant) of luminal diameter on CTA using NASCET-like criteria. All "significant" stenoses (21 out of 117 carotid bifurcations) had measurable calcium. We found a relatively strong correlation between percent stenosis and the calcium volume (Pearson's r = 0.65, P<0.0001). We also found that there was an even stronger correlation between the square root of the calcium volume and the percent stenosis as measured by CTA (r= 0.77, P<0.0001). Calcium volumes of 0.01, 0.03, 0.06, 0.09 and 0.12 cc were used as thresholds to evaluate for a "significant" stenosis. A receiver operating characteristic (ROC) curve demonstrated that thresholds of 0.06 cc (sensitivity 88%, specificity 87%) and 0.03 cc (sensitivity 94%, specificity 76%) generated the best combinations of sensitivity and specificity. Hence, this preliminary study demonstrates a relatively strong relationship between volume of calcium at the carotid bifurcation in the neck (measured by CT) and percent stenosis of the ICA below the skull base (as measured by CTA). Use of calcium volume measurements as a threshold may be both sensitive and specific for the detection of significant ICA stenosis. The significance of the correlation between calcium volume and ICA stenosis is that potentially a "score" can be obtained that will identify those at risk for high grade carotid stenosis.

Aged↗

Dynamic enhanced MRI of the subacromial bursa: correlation with arthroscopic and histological findings.

OBJECTIVE: To assess dynamic MRI with Gd-DTPA enhancement for evaluating inflammatory changes in the subacromial bursa. DESIGN AND PATIENTS: We detected the signal intensity changes in dynamic MRI of the subacromial bursa, and confirmed these macroscopically by arthroscopy and histologically. The signal intensity was measured using built-in software, and the enhancement ratio (E ratio) was calculated from dynamic MR images. In addition, as a parameter of the rate of the increase in the signal intensity from 0 to 80 s, the mean increase per second in the E ratio was obtained as the coefficient of enhancement (CE). The correlation was studied of the E ratio and CE with the arthroscopic findings (redness, villous formation, thickening and adhesion), and of the E ratio and CE with the histological findings (capillary proliferation, papillary hyperplasia, fibrosis and inflammatory cell infiltration) of the subacromial bursa. Of patients with shoulder pain, this study included those with rotator cuff injury; patients with rheumatoid arthritis or pitching shoulder disorders were excluded. There were 27 patients (15 men, 12 women) ranging in age from 25 to 73 years (mean 49.1 years). Dynamic MRI of the shoulder was also performed on the healthy side of 10 patients and in five normal young volunteers. RESULTS AND CONCLUSIONS: Changes in signal intensity on dynamic MRI were measured in the subacromial bursa. The E ratio (80 s) and CE (0-80 s) were significantly correlated with redness and villous formation as arthroscopic findings, positively correlated with capillary proliferation and papillary hyperplasia as histological findings (p < 0.05), and negatively correlated with fibrosis as a histological finding (p < 0.05) in the subacromial bursa. The patterns of dynamic curves were well correlated with the bursoscopic and histological findings of the synovium of the subacromial bursa. Dynamic MRI appears to correlate with inflammatory activity of synovium of the subacromial bursa. Clarifying the state of the synovium of the subacromial bursa may be useful in determining therapeutic strategies (e.g., indicating topical infusion of hyaluronic acid or steroids for preservative treatment and selecting the site). Furthermore, the evaluation may be useful for indicating surgery, selecting the technique, and evaluating preoperative and postoperative inflammatory changes.

Acromion↗

FDG uptake in breast cancer: correlation with biological and clinical prognostic parameters.

The aim of this study was to evaluate the possible correlation between preoperative FDG-PET results in human breast cancer and the prognostic markers Ki-67, c- erb B2, p53, oestrogen/progesterone receptor status, axillary lymph node status, tumour size and tumour grading. Seventy-five female patients with breast cancer were included in this prospective study. Patient selection was independent of tumour size and the suspected clinical stage of disease. A high-resolution full-ring scanner (Siemens ECAT HR+) was used for PET imaging. The FDG uptake of breast tumours was calculated as the tumour to background ratio (TBR). In resected cancer tissue specimens, the proliferative fraction was evaluated by Ki-67 immunostaining. Additionally, immunostaining of the prognostic markers c-erb B2, p53, and progesterone and oestrogen receptors was performed. Haematoxylin and eosin-stained sections were used for tumour grading. Correlations between FDG uptake and prognostic markers were assumed to be significant at P<0.05 using the Mann-Whitney U test. In ductal breast cancer, mean TBR was 17.3 (median 7.7, range 1.6-122.7), while in lobular cancer it was 6.5 (median 3.7, range 1.4-22.7). Mean proliferative fraction (% Ki-67 positive tumour cells) was 15%+/-13.8% (median 10%, range 0%-60%). Twenty-three carcinomas showed <5% Ki-67 positive tumour cells. Statistical analysis indicated a positive correlation between FDG uptake and proliferative index in ductal breast cancer ( P<0.0001, r=0.63). By contrast, there was no correlation between FDG uptake and c- erb B2 ( P=0.79), p53 ( P=0.92), tumour grading ( P=0.09), oestrogen receptor status ( P=0.41), progesterone receptor status ( P=0.34), axillary lymph node status ( P=0.90) and tumour size ( P=0.3). It is concluded that FDG uptake is significantly higher in ductal breast cancer than in lobular cancer ( P<0.05). FDG uptake correlates with proliferative activity assessed by Ki-67 immunostaining ( P<0.05). A significant correlation with the other prognostic markers, however, could not be demonstrated.

Adenocarcinoma↗

Histological grading in gastric cancer by Ming classification: correlation with histopathological subtypes, metastasis, and prognosis.

The aim of this prospective study was to analyze Ming's classification in correlation with other currently used classification systems of gastric cancer. In addition, we wanted to define the prognostic significance of the Ming classification system. The present study analyzed material of 117 patients with gastric carcinoma who underwent D2-gastrectomy with curative intent. All specimens were categorized according to International Union Against Cancer (UICC) classification, World Health Organization (WHO) classification, Borrmann classification, Laurén classification, Goseki classification, Ming classification, and tumor differentiation. For analysis of correlation between the classification systems, the correlation coefficient according to Spearman was calculated. The survival curves have been calculated according to the Kaplan-Meier method. According to the Ming classification, 38.5% of the carcinomas exhibited an expanding growth pattern, and 61.5% of specimens showed an infiltrating growth pattern. The subtypes according to the Ming and Laurén classification correlated significantly (P < 0.001). WHO classification (P < 0.001), tumor differentiation (P < 0.001), and Goseki classification (P < 0.001), as well as the macroscopic classification of Borrmann (P < 0.001) and the pT and pN categories of the UICC classification exhibited a highly significant correlation with the Ming classification (P < 0.001 and 0.001, respectively). Median overall survival was 31.3 months. In Kaplan-Meier analysis, the 3-year survival rates were lower in the infiltrative tumor type when compared to the expansive tumor type according to Ming (P = 0.0847). In multivariate analysis, only the UICC system presented as an independent prognostic factor in multivariate analysis (P < 0.001). This study shows that the Ming classification correlates significantly with the currently used classification systems for gastric cancer and with the UICC staging system, especially, the pT and pN category. The 3-year survival rates were lower in the infiltrative tumor type than in the expansive tumor type according to Ming. However, the Ming classification is not an independent prognostic factor.

Adenocarcinoma↗

DRD2/DARPP-32 expression correlates with lymph node metastasis and tumor progression in patients with esophageal squamous cell carcinoma.

BACKGROUND: Dopamine receptors (DRs) are members of seven transmembrane domain trimeric guanosine 5'-triphosphate (GTP)-binding protein-coupled receptor family. Through dopamine receptor activation, dopamine plays a significant role in regulating gene expression, such as induced tumor cell migration. MATERIALS AND METHODS: We investigated DRD1 and DRD2 expressions in patients with esophageal squamous cell carcinoma (ESCC) for immunohistochemistry and analyzed differences between DRD1, DRD2, and DARPP-32 expressions of clinicopathological features in 122 patients with ESCC. RESULTS: DRD1 immunostaining correlated with the pathologic grade (P = 0.0127), and DRD2 immunostaining correlated with the pathologic stage (P = 0.0432) and pN classification (P = 0.0112). A significant correlation was found between DRD1 and DRD2 expression (P = 0.0292). However, no correlation was observed between DRD1/DRD2 expression and DARPP-32 expression (P = 0.4555 and 0.4774, respectively). No correlation was observed between the DRD1/DRD2 expression and patient prognosis. To find the cooperative role between DRD1, DRD2, and DARPP-32 expressions, patients were classified into the different groups. In the DRD2/DARPP-32 combination, the (+/-) group was significantly correlated with pathologic stage (P = 0.0006), lymph node metastasis (P = 0.0001), pT (P = 0.0287), and tumor size (P = 0.0202). Moreover, patients with this combination showed a lower survival rate compared with the other three groups (P = 0.0287). CONCLUSIONS: We conclude that DRD2/DARPP-32 expression is associated with tumor progression and that DRD2/DARPP-32 expressions may help predict prognosis in patients with ESCC.

Adult↗

Correlation between clinicopathologic factors and kinetics of metabolic enzymes for 5-fluorouracil given to patients with colon carcinoma by two different dosage regimens.

PURPOSE: Using tumor tissue specimens from colon carcinoma patients given 5-fluorouracil (5-FU) by two different administration methods, we investigated the degree of correlation between clinicopathologic factors and the kinetics of metabolic enzymes for 5-FU. METHODS: Group A patients received 500 mg/day of 5-FU as a rapid infusion over 2 h for 3 days preoperatively, and group B patients received 500 mg/day of 5-FU as a continuous infusion for 3 days preoperatively. The activities of orotate phosphoribosyl transferase (OPRT), thymidine phosphorylase (TP), uridine phosphorylase (UP), and dihydropyrimidine dehydrogenase (DPD) were measured by separation on ion-exchange filter paper, by high-performance liquid chromatography (HPLC) with UV detection and by HPLC with radioactive flow monitoring, respectively, and the [(3)H]-5-fluorodeoxyuridine monophosphate binding site in thymidylate synthetase (TS) was determined as an index of the amount of TS using a radiobinding assay. The TS inhibition rate (TSIR) was calculated from the formula: 1-(TS(free)/TS(total))x100. Finally, 5-FU incorporation into RNA (FRNA) was measured by capillary gas chromatography-mass spectrometry. RESULTS: In group A patients, FRNA showed a positive correlation only with OPRT, and TSIR showed positive correlations with OPRT and TP, but a negative correlation with TS. In group B patients, FRNA showed a negative correlation with DPD, and TSIR showed a negative correlation with TS. No difference in TSIR levels was seen between groups A and B. FRNA was higher in group A than in group B, but the difference was not statistically significant. CONCLUSION: The method of administration may influence 5-FU metabolism in colon carcinoma patients.

Aged↗

Additional value of PET-CT in the staging of lung cancer: comparison with CT alone, PET alone and visual correlation of PET and CT.

Integrated positron emission tomography (PET) and computed tomography (CT) is a new imaging modality offering anatomic and metabolic information. The purpose was to evaluate retrospectively the accuracy of integrated PET-CT in the staging of a suggestive lung lesion, comparing this with the accuracy of CT alone, PET alone and visually correlated PET-CT. Fifty patients undergoing integrated PET-CT for staging of a suggestive lung lesion were studied. Their tumor, node, metastasis (TNM) statuses were determined with CT, PET, visually correlated PET-CT and integrated PET-CT. These TNM stages were compared with the surgical TNM status. Integrated PET-CT was the most accurate imaging technique in the assessment of the TNM status. Integrated PET-CT predicted correctly the T status, N status, M status and TNM status in, respectively, 86%, 80%, 98%, 70% versus 68%, 66%,88%, 46% with CT, 46%, 70%, 96%, 30% with PET and 72%, 68%, 96%, 54% with visually correlated PET-CT. T status and N status were overstaged, respectively, in 8% and 16% with integrated PET-CT, in 20% and 28% with CT, in 16% and 20% with PET, in 12% and 20% with visually correlated PET-CT and understaged in 6% and 4% with integrated PET-CT, versus 12% and 6% with CT, 38% and 10% with PET and 12% with visually correlated PET-CT. Integrated PET-CT improves the staging of lung cancer through a better anatomic localization and characterization of lesions and is superior to CT alone and PET alone. If this technique is not available, visual correlation of PET and CT can be a valuable alternative.

Adult↗

Human articular cartilage: in vitro correlation of MRI and histologic findings.

The aim of our study was to correlate MRI with histologic findings in normal and degenerative cartilage. Twenty-two human knees derived from patients undergoing amputation were examined with 1.0- and 1. 5-T MR imaging units. Firstly, we optimized two fat-suppressed 3D gradient-echo sequences. In this pilot study two knees were examined with fast imaging with steady precession (FISP) sequences and fast low-angle shot (FLASH, SPGR) sequence by varying the flip angles (40, 60, 90 degrees) and combining each flip angle with different echo time (7, 10 or 11, 20 ms). We chose the sequences with the best visual contrast between the cartilage layers and the best measured contrast-to-noise ratio between cartilage and bone marrow. Therefore, we used a 3D FLASH fat-saturated sequence (TR/TE/flip angle = 50/11 ms/40 degrees) and a 3D FISP fat-saturated sequence (TR/TE/flip angle = 40/10 ms/40 degrees) for cartilage imaging in 22 human knees. The images were obtained at various angles of the patellar cartilage in relation to the main magnetic field (0, 55, 90 degrees). The MR appearances were classified into five categories: normal, intracartilaginous signal changes, diffuse thinning (cartilage thickness < 3 mm), superficial erosions, and cartilage ulcers. After imaging, the knees were examined macroscopically and photographed. In addition, we performed histologic studies using light microscopy with several different stainings, polarization, and dark field microscopy as well as electron microscopy. The structural characteristics with the cartilage lesions were correlated with the MR findings. We identified a hyperintense superficial zone in the MR image which did not correlate to the histologically identifiable superficial zone. The second lamina was hypointense on MRI and correlated to the bulk of the radial zone. The third (or deep) cartilage lamina in the MR image seemed to represent the combination of the lowest portion of the radial zone and the calcified cartilage. The width of the hypointense second zone correlated weakly to the accumulation of proteoglycans in the radial zone. The trilaminar MRI appearance of the cartilage was only visible when the cartilage was thicker than 2 mm. In cartilage degeneration, we found either a diffuse thinning of all layers or circumscribed lesions ("cartilage ulcer") of these cartilage layers in the MR images. Early cartilage degeneration was indicated by a signal loss in the superficial zone, correlating to the histologically proven damage of proteoglycans in the transitional and radial zone along with destruction of the superficial zone. We found a strong effect of cartilage rotation in the main magnetic field, too. A rotation of the cartilage structures caused considerable variation in the signal intensity of the second lamina. Cartilage segments in a 55 degreesangle to the magnetic main field had a homogeneous appearance, not a trilaminar appearance. The signal behavior of hyaline articular cartilage does not reflect the laminar histologic structure. Osteoarthrosis and cartilage degeneration are visible on MR images as intracartilaginous signal changes, superficial erosions, diffuse cartilage thinning, and cartilage ulceration.

Aged↗

Are summit metabolism and thermogenic endurance correlated in winter-acclimatized passerine birds?

Small birds exhibiting marked winter improvement of cold tolerance also show elevated summit metabolic rates (maximum cold-induced metabolic rate) in winter relative to summer. However, relatively large increases in cold tolerance can occur with only minor increments of maximum cold-induced metabolic rate and geographic variation in cold tolerance is not always positively correlated with variation in maximum cold-induced metabolic rate. Thus, it is uncertain whether maximum cold-induced metabolic rate and cold tolerance are phenotypically correlated in small birds and no previous study has directly examined this relationship. I measured maximum cold-induced metabolic rate and cold tolerance (i.e., thermogenic endurance) over three winters in black-capped chickadees Poecile atricapillus, American tree sparrows Spizella arborea, and dark-eyed juncos Junco hyemalis. For raw thermogenic endurance data, residuals of maximum cold-induced metabolic rate and thermogenic endurance from mass regressions were significantly and positively correlated in juncos and tree sparrows, and their correlation approached significance for chickadees. Log10 transformation of thermogenic endurance and mass data gave similar results. These data provide the first direct evidence for a phenotypic correlation between maximum cold-induced metabolic rate and thermogenic endurance in small birds, although much of the variance in thermogenic endurance is explained by factors other than maximum cold-induced metabolic rate and the degree of correlation differs among species. Nevertheless, these data suggest that physiological adjustments producing elevated thermogenic endurance also produce elevated maximum cold-induced metabolic rate in small birds.

Acclimatization↗

Prolactin and thyroid hormones in patients with systemic sclerosis: correlations with disease manifestations and activity.

OBJECTIVE: To determine serum levels of prolactin (PRL) and thyroid hormones and to investigate the correlation between these hormones and different disease manifestations in patients with systemic sclerosis (SSc). METHODS: Twenty four patients with SSc (23 women, mean age 37.7+/-12.7) were subjected to thyroid hormones assessment. Prolactin (PRL) was assessed in 23 female patients. The patients were evaluated regarding different disease manifestations. Fifteen normal female volunteers were involved as controls. RESULTS: Serum levels of PRL in all patients was significantly higher than controls (16.75+/-9.06 for patients vs. 11.6+/-4.5 for controls with p<0.001). Eight patients out of 23 (34.8%) showed hyperprolactinemia. In patients with diffuse SSc (dSSc), PRL levels showed significant correlation with the rate of skin tethering (r = +0.72, p<0.01) and abnormal left ventricular filling pattern (decreasing E/A ratio), i.e., occurrence of diastolic dysfunction (r = +0.65, p<0.05). Hyperprolactinemia in all patients correlated significantly with disease duration (r = -0.42, p<0.05). Mean serum levels of free thyroxin (FT4) in all patients were significantly lower than the control group(7.46+/-2.7 for patients vs 10.47+/-2.5 with p<0.001). Eight out of all 24 patients (33.3%) showed hypothyroidism. In group A (duration<3 years); FT4 levels correlated significantly with Dlco% (r = +0.90, p<0.01). While in group B (duration>3 years), T4 hypothyroidism correlated significantly with hand joint restriction of motion (r = +0.66, p<0.01). Serum levels of triiodothironine (FT3) in all patients were nonsignificantly lower than the control group (4.8+/-2.3 for patients vs 5.3+/-1.9 for controls, P = NS). Three patients out of 24 (12.5%) showed T3 thyrotoxicosis. Serum levels of T3 correlated significantly with liver enzyme elevations (r = +0.46, p<0.05) and ESR (r = +0.41, p<0.05). CONCLUSION: This study demonstrates the close association between PRL or thyroid hormones and some organ involvement in SSc.

Adolescent↗

Correlation of IL-6 with the classical humoral disease activity parameters ESR and CRP and with serum cortisol, reflecting the activity of the HPA axis in active rheumatoid arthritis.

Rheumatoid arthritis (RA) is a systemic inflammatory disease with elevated levels of proinflammatory cytokines in peripheral blood, especially IL-6, but also IL-1 alpha and TNF alpha, for example, in different concentrations, depending on disease activity. A disturbed circadian rhythm of cortisol secretion and an overall elevated cortisol release in active RA, depending on disease activity, is known. The presented study examined correlations of IL-6 as the most important systemic mediator of the acute phase response in active RA with classical humoral disease activity parameters, such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), and with serum cortisol. We investigated 64 active RA patients, previously untreated with glucocorticoids. IL-6 was measured by ELISA from Pharmingen (San Diego), ESR by the method of Westergren and CRP by nephelometry (Behring Marburg, Germany). Cortisol was measured in 34 of these patients, using a fluorescence-polarization immunoassay (FPIA) from Abbott. We found correlations of IL-6 with CRP (p < 0.001, Spearman Rank Test, rs = 0.75), with ESR (p < 0.001, rs = 0.62) and with serum cortisol (p = 0.019, rs = 0.401). ESR and CRP correlate (p < 0.001, rs = 0.8) and cortisol also correlates with ESR (p = 0.002, rs = 0.52) and CRP (p < 0.001, rs = 0.57). IL-6 as an important systemic mediator of inflammation in RA correlates closely with CRP, as it induces its production, and with ESR. These three parameters correlate well with serum cortisol, which is increased in active RA, depending on disease activity. Thus, IL-6 is an important disease activity parameter in RA that is closely related to both the classical humoral disease activity and the HPA axis.

Arthritis, Rheumatoid↗

Correlation between capillary blood flow of retina estimated by SLDF and circulatory parameters of retrobulbar blood vessels estimated by CDI in diabetic patients.

BACKGROUND: The aim of this study was to investigate the correlation between the recordings of scanning laser Doppler flowmetry (SLDF) of the retina and the recordings of color Doppler imaging (CDI) of the retrobulbar circulatory parameters in diabetic patients without diabetic retinopathy. METHODS: Twenty-three diabetic patients without diabetic retinopathy were evaluated using SLDF for the apparent retinal circulation and using CDI for the apparent retrobulbar circulation in the central retinal artery, the central retinal vein and the short posterior ciliary artery. The circulatory parameters estimated in the retinal tissue using SLDF were velocity, volume and flow. The Circulatory parameters that were recorded using the CDI method were peak systolic velocity (PSV), end-diastolic velocity (EDV), mean velocity (MV), pulsatility (PI) and resistivity index (RI). We obtained the correlation coefficients between parameters of SLDF and CDI. Multiple regression analysis was performed with "flow" parameter of SLDF recordings as a dependent variable and all estimated CDI parameters as independent variables. Multiple linear regression was also performed, including the "flow" parameter of SLDF recordings as a dependent variable and PI of the CDI parameters of all the measured blood vessels as independent variables. RESULTS: The "velocity" parameter of SLDF was significantly correlated with the PI in the central retinal artery (P=0.02), PI and RI in the central retinal vein (P=0.01; P=0.01) and the PSV, MV, PI and RI in the short posterior ciliary artery, as recorded by CDI (P=0.003; P=0.02; P=0.002; P=0.01). The "volume" parameter of SLDF was significantly correlated with the PI and RI in the central retinal vein (P=0.03; P=0.03) and the PSV in the short posterior ciliary artery (P=0.03), as recorded by CDI. The "flow" parameter of SLDF was significantly correlated with the PI and RI in the central retinal vein (P=0.01; P=0.01) and the PSV, MV, PI and RI in the short posterior ciliary artery (P=0.003; P=0.03; P=0.002; P=0.01) as measured by CDI. The multiple regression analysis was statistically non-significant (P=0.86). The multiple linear regression analysis indicated that from among the PI of the evaluated blood vessels, the PI of the short posterior ciliary artery was the most significant predictor of the "flow" parameter of SLDF (P=0.01). CONCLUSION: This study suggests a positive correlation between the recordings of SLDF of the retinal tissue and the retrobulbar circulatory parameters of the CDI in diabetic patients without diabetic retinopathy.

Blood Flow Velocity↗