Effects of EGF and allopurinol on prostaglandin and lipid peroxide levels in mucosa of stomach in restraint cold stress.

The cold and restraint gastric stress models were used in rats. Mucosal levels of prostaglandins, which have a protective effect on cells, and lipid peroxidation, a possible etiological factor in stress-induced gastric mucosal injuries, were investigated. Epidermal growth factor (EGF), which protects the gastric tissue from stress-induced lesions, and allopurinol, which inhibits xanthine oxidase, were given intraperitoneally. Both EGF and allopurinol decreased lipid peroxidation at the mucosal surface of the stomach. At the same time, allopurinol increased the serum gastrin levels and decreased the mucosal prostaglandin levels. It is concluded that EGF protects the gastric mucosal surface by way of increased tissue prostaglandin levels. EGF also decreased both serum gastrin and tissue malondialdehyde, an indicator of lipid peroxidation.

Tc-99m HMPAO brain perfusion imaging in young Down's syndrome patients.

Down's syndrome (DS) is characterized by moderate mental retardation and a variety of abnormalities involving multiple organ systems. There is a high incidence of Alzheimer's disease (AD) type dementia beyond the age of 35. In this study, single photon emission computed tomography (SPECT) brain perfusion imaging of young Down's syndrome patients was performed to define the perfusion pattern. Tc-99m HMPAO brain perfusion SPECT was performed on 17 young DS patients, aged 3-24 years (mean: 10.9+/-5.9 years). None of the patients had dementia symptoms. Brain perfusion scans were acquired 15 min after i.v. injection of 12 MBq/kg of Tc-99m HMPAO using a single head rotating gamma camera. Images were analyzed visually and semiquantitatively by defining side-to-side asymmetry index. Nine DS cases showed normal brain perfusion. Eight of the 17 cases revealed mostly unilateral parieto-temporal, parieto-occipital and frontal hypoperfusions. The side-to-side asymmetry indices for these visually interpreted regional brain perfusion abnormalities ranged from 6 to 15%. These findings revealing mostly unilateral parieto-temporal and frontal hypoperfusions may not be considered as predictive patterns of dementia related Alzheimer type perfusion deficits in DS. However, such findings may connect to other functional imaging studies related to the higher cortical dysfunction in mental retardation.

Tl-201 scintigraphy, mammography and ultrasonography in the evaluation of palpable and nonpalpable breast lesions: a correlative study.

PURPOSE: To determine the feasibility of Tl-201 as a tumor localizing agent in palpable and nonpalpable breast lesions, in comparison with mammography and ultrasonography (US), and to evaluate the contribution of these modalities to each other in obviating biopsy. MATERIALS AND METHODS: Seventy-two palpable and nonpalpable breast lesions were prospectively classified as benign, indeterminate, or malignant according to the sonographic and mammographic criteria and were further analyzed with Tl-201 scanning. These classifications were compared with biopsy results. The sensitivity, specificity, accuracy, false positive and false negative rates (FPR, FNR), negative and positive predictive values (npv, ppv) were calculated for each individual modality and combination of modalities to evaluate the contribution of these three techniques to each other. RESULTS: Of 72 lesions 52 were histologically malignant and 20 were benign. Overall, mammography was the most sensitive (92%) and Tl-201 was the most specific (75%) of the three modalities. Mammography + Tl combination was the most specific (90%) and accurate (97%) of dual combinations. In mammographically or sonographically indeterminate cases, Tl-201 was much more specific (75% versus 37% for mammography and US) and more accurate (82% versus 36% for mammography and 54% for US) than the other two modalities, and mammography + Tl combination was significantly superior to other dual combinations (87% specific and 91% accurate). Use of Tl-201 scanning as an adjunct to mammography + US combination increased the specificity, ppv, and accuracy rates overall, particularly in mammographically or sonographically indeterminate cases. CONCLUSIONS: In mammographically and sonographically indeterminate breast lesions thallium scanning may be offered as a third step of investigation to obviate biopsy.

201Tl scintigraphy in the evaluation of palpable and nonpalpable breast lesions: correlation with mammography and ultrasonography.

AIM: Our goal was to determine the clinical usefulness of Tl-201 to identify breast cancer in patients with suspicious breast lesions on clinical examination, and/or abnormal radiologic (mammography and/or ultrasonography) findings. METHODS: Tl-201 scintigraphy were performed in sixty-eight patients with 70 breast abnormalities (51 palpable, 19 nonpalpable) and compared with mammography and ultrasonography (US). Early (15 min) and late (3 h) images of the breasts were obtained following the injection of 111 MBq (3 mCi) of Tl-201. Visual and semiquantitative interpretation was performed. RESULTS: Final diagnosis confirmed 52 malignant breast lesions and 18 benign conditions. Tl-201 visualized 47 of 52 (90%) overall malignant lesions. Thirty-eight of 40 (95%) palpable and 9 of 12 (75%) nonpalpable breast cancers were detected by Tl-201 scintigraphy. The smallest mass lesion detected by Tl-201 measured 1.5 x 1.0 cm. Eleven breast lesions were interpreted as indeterminate by mammography and/or sonography. Tl-201 scintigraphy excluded malignancy in 7 of 8 (88%) patients with benign breast lesions interpreted as indeterminate. Five of the 18 (28%) benign breast lesions showed Tl-201 uptake. None of the fibroadenoma and fibrocystic changes accumulated Tl-201. Tl-201 scintigraphy, mammography and ultrasonography showed 90%, 92%, 85% overall sensitivity and 72%, 56%, 61% overall specificity respectively. Twenty-one of the 28 (75%) axillary nodal metastatic sites were also detected by Tl-201. In malignant and benign lesions, early and late lesion/contralateral normal side (L/N) ratios were 1.58 +/- 0.38 (mean +/- SD) and 1.48 +/- 0.32 (p > 0.05), 1.87 +/- 0.65 and 1.34 +/- 0.20 (p < 0.05) respectively. The mean early and late L/N ratios of malignant and benign groups did not show statistical difference (p > 0.05). CONCLUSION: Overall, Tl-201 scintigraphy was the most specific of the three methods and yielded favourable results in palpable breast cancers, while it showed lower sensitivity in nonpalpable cancers and axillary metastases. Combined use of Tl-201 scintigraphy with mammography and US seems to be useful in difficult cases, such as dense breasts and indeterminate breast lesions.

Evaluation of renal function following treatment with extracorporeal shock wave lithotripsy (ESWL): the use of whole-kidney, parenchymal and pelvic transit times.

The aim of this prospective study was to assess the efficacy of using whole-kidney, mean parenchymal and pelvic transit times to evaluate renal function following treatment with extracorporeal shock wave lithotripsy (ESWL). Fifteen patients were evaluated 24-48 h before and after ESWL therapy using 99Tcm-DTPA renal scintigraphy. Using deconvolution analysis, whole-kidney, mean parenchymal and pelvic transit times were calculated and the pre-ESWL values were compared with the post-ESWL values. In both kidneys, there were no significant changes in the glomerular filtration rate or relative renal uptake when compared with the pre-ESWL values. The mean whole-kidney transit time of the tracer did not change significantly during the post-ESWL period. In the treated kidney, the mean post-ESWL parenchymal transit time was significantly increased (P < 0.05), while the mean pelvic transit time was significantly decreased (P < 0.05). In the untreated kidney, there were no significant changes in any of these parameters. We conclude that the dual use of parenchymal and pelvic transit times is more sensitive than the mean whole-kidney transit time and other measures, such as glomerular filtration rate and relative renal uptake, for the assessment of outcome of therapy and other related post-ESWL changes.

Evaluation of malignant and benign lung lesions with 99Tcm-tetrofosmin.

99Tcm-tetrofosmin planar imaging was performed in 30 patients with malignant and benign lung lesions. There were 21 cases of primary lung cancer (10 squamous cell, 5 small cell, 4 adenocarcinoma and 2 large cell) and 9 benign lung lesions (4 pneumonia, 3 tuberculosis, 1 infected bronchiectasis and 1 bronchiectasis obliterans). Anterior and posterior planar thorax images were obtained 30 min after the intravenous injection of 740 MBq (20 mCi) of 99Tcm-tetrofosmin. Visual and quantitative evaluations were performed. For the quantitative evaluation, regions of interest were drawn over the lesioned area (L) and over the contralateral non-lesioned area (N). Of 21 malignant primary lesions; 19 (90%) showed 99Tcm-tetrofosmin accumulation. Four (44%) of the nine benign lung lesions (3 cases of pneumonia and the one case of active tuberculosis) showed uptake. The mean L/N ratios for the malignant and benign lesions were 1.63 +/- 0.29 and 1.64 +/- 0.19, respectively. There were no significant differences (P > 0.05) in the L/N ratios of the malignant and benign lesions or the various histological types of cancer. In conclusion, 99Tcm-tetrofosmin was highly sensitive (90%) in detecting malignant lung lesions, but it had poor specificity (55%).

Serum levels of insulin-like growth factor-I and insulin-like growth factor binding protein-3 in children with insulin-dependent diabetes mellitus.

Pubertal development has recently been evaluated from the standpoint of changes in insulin-like growth factor (IGF)-I and IGF-binding protein-3 (IGFBP-3) levels in healthy children. We studied puberty related changes in serum IGF-I and IGFBP-3 levels in 24 patients (11 prepubertal) with insulin dependent diabetes mellitus (IDDM) and 26 healthy subjects (14 prepubertal). Serum IGF-I and IGFBP-3 levels were assayed using immunoradiometric assays and radioimmunoassays, respectively. Serum IGF-I and IGFBP-3 levels in diabetics did not increase during puberty, as opposed to those in healthy children. Serum IGF-I and IGFBP-3 levels of diabetic patients were found to be lower than those of control subjects during puberty (p < 0.0001 and p < 0.05, respectively). Proteolysis is believed to be a general mechanism to increase IGF bioavailability in the presence of IGFBPs. Increased IGFBP-3 protease activity has been shown in sera of children with IDDM as well as a decrease in this activity in response to insulin therapy. Our data displaying low IGFBP-3 levels in diabetic children may be due to increased proteolysis, which also causes a shift in IGF-I to its lower molecular weight forms. Higher rate of clearance of the latter may be the reason for the low IGF-I levels we observed in children with IDDM. The moderate correlation between insulin dose and IGFBP-3 levels (r = 0.5, p < 0.01) may suggest insulin to be a contributing factor in the regulation of IGFBP-3 levels. We conclude that regulation of IGF-I and IGFBP-3 concentrations is disturbed in children with IDDM, in particular during adolescence.

Increased accumulation of Tl-201 in monostotic Paget's disease of the patella: evaluation with quantitative analysis.

Monostotic Paget's disease of the patella was detected with Tc-99m MDP and Tl-201 scans. Diffuse intense uptake of MDP in the left patella was observed on the blood-pool and late phases of the bone scan. Tl-201 imaging was performed to differentiate a malignant process and showed diffuse marked accumulation at the same site. Semiquantitative analysis of the patella region on both Tc-99m MDP and Tl-201 scans did not support a diagnosis of cancer. Radiographs showed the features of Paget's disease of the bone. Findings of a pathologic evaluation were compatible with the diagnosis of osteitis deformans. This case represents the unusual skeletal involvement of monostotic Paget's disease of the bone in the patella. Tl-201 accumulation in the Paget's lesion was suggested to be caused by increased metabolic activity of the lesion but was not indicative of a malignant process.

The effects of contrast media on renal function in children: comparison of ionic and non-ionic agents.

Nephrotoxicity is a common side effect of intravascular contrast media (CM). Although nephrotoxicity of ionic CM has been widely demonstrated, recent studies suggest that newer and more costly non-ionic agents are not less nephrotoxic. We studied the hemodynamic, hematologic and nephrotoxic effects of CM prospectively in 38 patients (ages six months-16 years) with or without risk factors predisposing to nephropathy and compared ionic and non-ionic CM. We performed intravenous urography (IU) with a ionic CM, sodium meglumine diatrizoate (n = 18) and a non-ionic CM, iohexol (n = 20). The patients were divided into three groups according to glomerular filtration rate (GFR) [GFR < or = 50 (n = 9), 50-80 (n = 13), > or = 80 ml/min/1.732 (n = 26)]. Eleven patients had risk factors for nephropathy. Blood pressure, heart rate, ECG, urine and blood samples were obtained 24 hours and one hour before as well as one, 24, and 48 hours after CM infusion. Although a significant increase was found in urine specific gravity, protein/creatinine ratios and serum Na and creatinine levels, the increased levels were within normal limits. We observed a significant reduction in Hb and Htc and urinary prostaglandin E1 levels. Many of the changes observed in the urine and serum values after the use of CM were minor, insignificant and transient, later returning to their initial values. The GFR levels, the presence of risk factors and the use of ionic vs. non-ionic CM had no effect on the results. The elevated urinary basal beta-2-microglobulin levels further increased after CM in patients with low GFRs. It was concluded that non-ionic CM was not superior to ionic CM in patients with GFRs greater than 50 ml/min regardless of predisposing risk factors. One of the non-invasive radiological methods is advised instead of IU in patients with low GFRs.

Brain perfusion assessed by 99mTc-ECD SPECT imaging in pediatric patients with neurally mediated reflex syncope.

BACKGROUND: The involvement of cardiogenic and neurogenic mechanisms in neurally mediated reflex syncope is well documented. In our previous studies in patients with neurally mediated reflex syncope, we have found evidence for differential regulation of the noradrenergic receptors in tilt-positive and tilt-negative patients. The present work concentrates on the observations of differences in regional brain perfusion using brain SPECT via injecting the patient at the completion of the tilt test. METHODS AND RESULTS: The following study was designed to assess the reduction and regional differences in cerebral blood flow by means of SPECT using technetium-99m labeled V-oxo-1,2-N1ethylenedylbisl-cysteine diethylester (ECD) in patients with an injection during tilt testing. Twenty patients with NMS were included in the study with a mean age of 12.2 years (age range; 8-16 years). HUT was positive in 10 patients and negative in 10 patients. When tilt (+) and tilt (-) were evaluated together, regional cortical/cerebellum ratios were ranging from 0.85 to 1.25 in different cortical areas with highest variability of perfusion index in left frontoparietal cortex. The lowest perfusion index values were observed in the left anterior frontal region followed by the left prefrontal-frontoparietal-anterior, parietal-orbito frontal, and anterior temporal regions where perfusion is predominantly supplied via the anterior and middle cerebral arteries, while these differences did not reach statistical significance in a single dominant region compared to the other regions examined using ANOVA (P > 0.05) with this sample size. Decreases in [99mTc]ECD uptake were more widespread regionally on the left hemisphere than were decreases in right side of the brain. However when tilt- and tilt+ groups were compared, perfusion was significantly lower in the right periinsular posterior parietal and temporal regions (P < 0.05) in tilt + group. CONCLUSION: These tilt induced regional differences in brain perfusion suggest the distinct roles of middle cerebral artery dominant territory-related vasodepressor compensation mechanisms in neurally mediated reflex syncope phenomena where cerebral lateralization of cardiac control and insular ischemia may play an important role.

Comparison of sputum and serum eosinophil cationic protein (ECP) levels in nonatopic asthma and chronic obstructive pulmonary disease.

The aim of the present study was to investigate whether sputum eosinophil cationic protein (ECP) concentrations could be a useful marker in the differential diagnosis between intrinsic asthma and chronic obstructive pulmonary disease (COPD). For this purpose total blood eosinophil counts were obtained and concentrations of serum and sputum ECP from 10 nonatopic asthmatics with a mild attack and 9 COPD patients with acute exacerbation were measured by radioimmunoassay. Mean serum ECP concentration was 54.3 +/- 23.0 micrograms/L in the asthmatic group and 83.3 +/- 79.2 micrograms/L in the COPD group (p: n.s.). In the group of asthmatics mean sputum ECP level was 984.5 +/- 1245.5 micrograms/L/g sputum and in the COPD group it was 417.5 +/- 363.5 micrograms/L/g sputum. There was no significant difference in sputum ECP levels between patients with asthma and COPD. We conclude that neither sputum nor serum ECP levels are useful markers in differential diagnosis of asthma attack and acute exacerbation of COPD.

Dual isotope myocardial perfusion SPECT in the detection of coronary artery disease: comparison of separate and simultaneous acquisition protocols.

A time-saving dual isotope acquisition protocol was carried out for the simultaneous assessment of stress and rest myocardial perfusion, and the diagnostic value of the technique was evaluated using coronary angiography results as a reference. Fifty-five patients undergoing coronary angiography before surgery were included in the study. Stress tests were applied, either with a treadmill (25 patients) or dobutamine infusion (30 patients in 5-40 micrograms/kg/min doses). All patients received 3 mCi of thallium-201 at rest. Stress tests were applied 30 minutes later, and at peak stress 7 mCi of 99mTc-MIBI was administered. A dual isotope SPECT study was carried out one hour after the administration of 99mTc-MIBI. Tracer doses were optimised with phantom studies, and the down-scatter of each radioisotope on the other data was investigated. In 30 patients, 10 minutes after the 201Tl injection a separate rest 201Tl acquisition was also performed, to compare the data with dual acquisition. 201Tl rest imaging SPECT data was evaluated by segmental analysis according to coronary artery regions. In 55% of the segments stress defects were observed. Similar results were obtained for the detection of defect reversibility; i.e. stress MIBI/rest 201Tl (75%) and stress MIBI/simultaneous 201Tl (78%). The overall sensitivity and specificity of simultaneous dual isotope SPECT with respect to coronary angiography results were 88% and 84%, respectively. A good correlation and no significant difference was observed between the two acquisition methods. However, the simultaneous acquisition protocol has many advantages, i.e. halving the acquisition time, shortening the overall decision-making time, and decreasing unmatched stress-rest artifacts.

Regional cerebral blood flow in Angelman syndrome.

A patient with typical features of Angelman syndrome--a genetically inherited disorder involving developmental delay, ataxia, episodes of paroxysmal laughter and brachiocephaly--was studied with single-photon emission tomography. Hypoperfusion found in the left frontal and left temporoparietal regions can provide insights into the functional cerebral pathology, which may be due to a disturbance of the developmental process related to a chromosomal abnormality.

Serum levels of carboxyterminal propeptide of type I procollagen and aminoterminal propeptide of type III procollagen in children with growth retardation.

Somatic growth follows proliferation of cells and deposition of material in the extracellular matrix. This process takes place in both bone and soft tissue. The carboxyterminal propeptide of type I procollagen (PICP) and aminoterminal propeptide of type III procollagen (PIIINP) are the major extracellular components of these. We measured serum levels of these procollagens by radioimmunoassay (RIA) in 23 children (aged 6.6 to 12.2, mean: 9.9) with growth retardation (seven of these with growth hormone (GH) deficiency) and in 14 healthy children (aged 6.0 to 12.8, mean: 8.8). A statistically significant difference was revealed between the PICP levels of GH-deficient children and healthy children (P < 0.05). But there was only a marginally significant difference between PICP concentrations of the GH-deficient and the non-deficient (GH-normal) retarded group (P = 0.05). No correlation was observed between PICP, PIIINP and age, height z-score. Our data have demonstrated that the measurement of serum PICP levels may be useful in the diagnosis of GH deficiency.

Atrial natriuretic peptide concentrations in children with pulmonary hypertension: correlation with hemodynamic measurements.

To define the relation between atrial natriuretic peptide (ANP) and hemodynamic parameters in children with pulmonary artery hypertension, we measured the ANP concentrations of the femoral vein, right atrium, pulmonary artery, left atrium and left ventricle, or femoral artery in 32 patients during right or left heart catheterization. There is a strong correlation among the ANP levels obtained from different locations (p < 0.001), and these ANP levels are positively correlated with pulmonary arterial pressures and pulmonary resistance. Patients were divided into two groups according to their pulmonary arterial pressure. The group with pulmonary arterial systolic pressure higher than 31 mmHg had higher ANP levels than the group with pulmonary arterial systolic pressure lower than 31 mmHg. When patients were grouped according to their pulmonary resistance, ANP levels in the group with pulmonary resistance over 2 U/m2 were higher than those in the group with pulmonary resistance lower than 2 U/m2. In this study ANP levels showed a correlation with the right ventricular systolic pressure. A correlation was not seen between ANP levels and the flow ratios or the presence of shunt. The results of our study suggest that ANP should be considered an important factor in pulmonary hypertension, independent of other factors.

Stress hyperglycemia in minimally invasive surgery.

This study examined the selected hormonal responses to, and hormone-mediated glucose metabolism during minimally invasive surgery in, patients undergoing laparoscopic cholecystectomy for symptomatic gallstone disease. Thirty-two patients with symptomatic gallstone disease were included in this study and scheduled for open or laparoscopic procedure in a randomized trial. Results are expressed as mean and standard error of the mean. Statistical evaluations were performed with Mann-Whitney U and Wilcoxon signed-rank tests. Blood cortisol, glucagon, insulin, and glucose concentrations were measured immediately in the preoperative period and 6 h after surgery. Blood cortisol, glucagon, and glucose concentrations increased significantly after open and minimally invasive surgery, while insulin levels and the insulin:glucagon ratio remained unchanged. The rise of glucagon and cortisol values was found to be significantly higher in the postoperative period of the open procedure, than in the laparoscopic approach. However, in the patients who underwent open surgery, the increase in glucose concentrations was not significantly higher in the postoperative period. Surgery-induced hormonal effects on the islets increase glucagon and suppress insulin secretion. The glucagon-mediated increase in hepatic glucose production is excluded by the posttraumatic insulin levels from the insulin-sensitive tissues. A bihormonal setting favors a greater rate of hepatic glucose production in both open and laparoscopic surgery. Hormonal changes do reflect the degree of surgical stress, but their metabolic consequences are not parallel to the grade of surgical trauma in minimally invasive surgery.

Tumor necrosis factor-alpha (TNF-alpha) in pleural fluids.

Our study was undertaken to investigate the role of tumor necrosis factor-alpha (TNF-alpha) at the site of disease activity in tuberculous pleuritis (TP). Concentrations of TNF-alpha were measured directly by radioimmunoassay (RIA) in the pleural fluid (PF) and plasma (P) of patients with TP (n = 14), malignant effusions (n = 18) and transudates (n = 7). Among these three groups mean plasma levels of TNF-alpha were not statistically significant (P > 0.05), but in the TP group mean levels of TNF-alpha in PF were significantly higher than in the cancer and transudate groups (P < 0.001), and there was no significant difference between the cancer and transudate groups (P > 0.05). These results may indicate a local synthesis of TNF-alpha by cells within the pleural cavity in this disease.

Changes in serum levels of IGF-I and IGFBP-3 in children with chronic renal failure.

The significance of serum insulin-like growth factor I (IGF-I) and insulin-like growth factor binding protein 3 (IGFBP-3) levels in uremia is still controversial. In this study we measured serum IGF-I by immunoradiometric assay (IRMA) and IGFBP-3 levels by specific radioimmunoassay (RIA) in 28 children (aged 3-16 years) with end-stage (n = 14, on hemodialysis) and pre-terminal renal failure (n = 14) and in 15 age-matched healthy children. Thyroid function of the patients was also investigated and GH-stimulation tests with L-Dopa and insulin were performed. Neither IGF-I nor IGFBP-3 levels significantly correlated with mean height SDS for bone age or for chronological age in either non dialysis patients or pubertal (n = 10) or prepubertal patients (n = 18). These data was consistent with the concept that growth in CRF was not related to abnormalities in serum IGF-I or IGFBP-3 levels.

The changes in serum type I and III procollagen, insulin-like growth factor-I and insulin-like growth factor binding protein-3 levels in children with chronic renal failure.

Serum levels of carboxyterminal propeptide of type I procollagen (PICP) and aminoterminal propeptide of type III procollagen (PIIINP) can be used as markers of bone formation and the evaluation of children with growth disorders. We measured the serum levels of these collagens by radioimmunoassay (RIA), insulin-like growth factor I (IGF-I) (by immunoradiometric assay) and insulin-like growth factor binding protein-3 (IGFBP-3) (by RIA) levels in 24 children aged between 4 and 14 years with chronic renal failure (CRF) (n = 12 dialysis, n = 12 non-dialysis) and 12 age-matched healthy controls, to find out whether these parameters have a prognostic or therapeutic value on monitoring of growth retardation in CRF. Mean serum IGFBP-3 and PIIINP levels in the dialysis patients were higher than the control group, the difference between the groups was statistically significant (P < 0.05). It seemed that the pubertal stage of the patients did not affect the levels of PICP, PIIINP, and IGFBP-3 while serum IGF-I levels in pubertal patients were significantly higher than those in prepubertal patients (P < 0.001). There was no significant correlation between PICP and PIIINP in any patients. Neither PICP nor PIIINP correlated with height z-score, bone age, IGF-I, or IGFBP-3. It was concluded that the increased serum IGFBP-3 and PIIINP levels in chronic renal disease are poor prognostic indicators leading to progressive renal failure and end-stage renal disease (ESRD). Further investigations into the effects of these collagens on growth failure associated with CRF are needed.