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Biomedical subjects

C Catalano

Publications and source records attributed to C Catalano.

At least 37 records · Page 2Linked to original sources
PubMed2001

Multislice spiral computed tomography angiography of mesenteric arteries.

The introduction of multislice technology has improved and expanded the clinical applications of computed tomography angiography (CTA), and it is now possible to detect subtle vascular abnormalities. We optimised a high resolution CTA protocol to study the anatomy of mesenteric arteries with a multislice spiral CT scanner. We showed that multislice CTA produces images of high quality, with excellent anatomical visualisation of the main mesenteric trunks, and small collateral vessels. CTA may facilitate the diagnosis of vascular diseases, such as chronic mesenteric ischaemia, as well as acute disorders such as gastrointestinal bleeding.

Adult↗
PubMed2001

Effects of acetyl-L-carnitine on the formation of fatty acid ethyl esters in brain and peripheral organs after short-term ethanol administration in rat.

Increasing evidence suggests that Fatty acid ethyl esters (FAEE) play a central role in ethanol induced organ damage. In the current study we measured FAEE formation in rats after short-term oral administration of ethanol, in the presence and absence of pre-treatment with acetyl-L-carnitine. Ethanol treatment caused a significant increase in the levels of FAEE, particularly in the brain and heart, but also in the kidney and liver. Increases in FAEE were associated with a significant increase in FAEE synthase activity, GSH transferase activity, and lipid hydroperoxide levels. Pretreatment with acetyl-L-carnitine resulted in a significant reduction of FAEE accumulation, decrease in FAEE synthase and GSH transferase activities, and lipid hydroperoxide levels. Administration of acetyl-L-carnitine greatly reduced the metabolic abnormalities due to non-oxidative ethanol metabolism, through an increment in lipid metabolism/turnover and by the modulation of the activities of enzymes associated with FAEE synthesis. These results suggest a potentially important pharmacological role for acetyl-L-carnitine in the prevention of alcohol-induced cellular damage.

Acetylcarnitine↗
PubMed2001

Influence of long-term diabetes on renal glycogen metabolism in the rat.

BACKGROUND/AIMS: The effects of acute insulin deficiency on the kidney have been investigated in animal models of experimental diabetes; however, the impact of long-term diabetes has not been determined. METHODS: We measured renal glycogen contents in streptozotocin (STZ)-diabetic rats 3 weeks (n = 12) or 9 months (n = 12) after the induction of diabetes, and in 2 groups of control rats of similar age (n = 16 and n = 12, respectively), in the fed state and after a 24-hour fast. RESULTS: Diabetic rats had high glucose levels, low insulin but normal glucagon concentrations in portal blood. In the fasting state, kidney glycogen content was very low in both young control and young diabetic rats (54 +/- 15 and 189 +/- 26 microg/g, respectively, mean +/- SD); in contrast, glycogen levels were markedly elevated in rats with long-standing diabetes as compared to old nondiabetic animals (2,628 +/- 1,023 +/- and 1,968 +/- 989 microg/g of diabetic rat, fasting and fed, respectively, p < 0.001 vs. 0 +/- 0 and 4 +/- 6 microg/g of control rats). On electron microscopy, large glycogen clusters were localized to the renal tubules. Kidney phosphorylase activity was higher, and synthase activity lower in diabetic than control rats (p < 0.05 for both), whereas kidney glycogen was strongly related to plasma glucose levels, suggesting that the enzyme changes were secondary to glycogen accumulation itself. Renal hexosephosphates and fructose-2,6-bisphosphate contents were both increased in long-term diabetic rats (p < 0.05), implying enhanced fluxes through both glycolysis and gluconeogenesis. CONCLUSION: In chronic, untreated diabetes glycogen accumulates in the renal tubules; prolonged hyperglycemia is the sole driving force for this phenomenon.

Aging↗
PubMed2001

Angiotensin-converting-enzyme inhibitor administration must be monitored for serum amylase and lipase in order to prevent an acute pancreatitis: a case report.

Some clinical cases published in literature show that angiotensin-converting enzyme (ACE)-inhibitor administration may cause acute pancreatitis. In this work, the authors report a case of a patient affected by hypertension. Upon admission, the authors started antihypertensive therapy using captopril, which caused an important amylase and lipase rise within 13 days. When the ACE-inhibitor therapy was stopped, a rapid decrease of the serum enzyme was observed within 3 days. The high levels of serum amylase and lipase were linked to neutrophilia but were not associated with relevant symptomatic findings or features of pancreatopathy. The absence of the usual conditions that may cause pancreatitis, such as biliary stasis, hypercalcemia, or alcohol abuse, and the rapid decrease of serum enzyme levels after drug suspension suggested an ACE-inhibitor-induced pancreatitis. This is the first clinical report of an ACE-inhibitor-induced pancreatitis in which captopril administration was found after hospitalization. The drug suspension probably prevented other complications. This case report suggests that, when ACE-inhibitor administration is started, serum amylase and lipase should be monitored in order to prevent acute pancreatitis without waiting for clinical evidence of a pancreatopathy.

Acute Disease↗
PubMed2001

[Diffusion-weighted echo-planar sequences for the evaluation of the upper abdomen: technique optimization].

PURPOSE: To optimize the technique for the evaluation of molecular diffusion in the abdomen. MATERIAL AND METHODS: Fifteen healthy volunteers, 6 males and 9 females, ranging in age between 24 and 31 years underwent an MRI evaluation of the upper abdomen, using a superconductive 1.5T magnet (maximum gradient strength, 25 mT/m; minimum rise time 600 ms), equipped with phased array abdominal multicoil. Diffusion study was performed with a single-shot Inversion Recovery Spin-Echo Echo-planar sequence (IR-SE-EPI) with the following parameters: TR = infinite; TE=101 ms; matrix 128 yen 128; receiver bandwidth 2080 Hz/pixel; slices: n.20; slice thickness: 8 mm; acquisition time: 5.41 s. For diffusion weighting the following b values were employed: b=30 mm/s2, b=300 mm/s2 e b=500 mm/s2. Both qualitative and quantitative (calculation of linear regression analysis and of apparent diffusion coefficient) image analysis was performed. RESULTS: Image quality was graded as diagnostic in all the cases. Image quality decreased with the increase of b values: at low b values, the anatomy of upper abdominal organs was easily recognized, whereas, at high b values, the same organs could not be adequately assessed unless the images were compared with those obtained with low b values. Magnetic susceptibility artifacts were observed in all the cases; no significant chemical-shift artifacts were observed as the fat saturation pre-pulse was employed. Quantitative analysis demonstrated an apparent diffusion coefficient of 1.58 s/mm2 for the liver, 1.61 s/mm2 for the spleen and 5,14 s/mm2 for the gallbladder. A statistically significant difference (p<0.001) was observed between parenchymatous organs (liver and spleen) and gallbladder, presenting as a stationary fluid. CONCLUSIONS: Diffusion-weighted MR sequences may be implemented for abdominal studies, but the optimization of same parameters is slightly different compared with neuroradiologic applications. The potential applications are interesting above all as regards the characterization of focal liver lesions. Further developments are awaited in both sequence optimization (greater stability and lower sensitivity to magnetic susceptibility artifacts) and data analysis, with more complex algorithms able to better quantify the real diffusion coefficient.

Abdomen↗
PubMed2001

Induction of heat shock protein synthesis in human skin fibroblasts in response to oxidative stress: regulation by a natural antioxidant from rosemary extract.

Reactive oxygen species have been implicated in the pathogenesis of the severe connective tissue damage present in several photodermatologic disorders, including drug-induced phototoxicity, porphyrias and photoaging. Oxidative stress has been shown to alter the expression of mammalian antioxidant enzymes and to enhance numerous transcription factors, including nuclear factor-kappa B, stress-activated protein kinase and heat shock factor. The latter represents the transcription factor for the synthesis of cytoprotective proteins called heat shock proteins. In this study, we investigated the role of oxidative stress and sulfdryl (SH) groups in the induction of HSP70 in human skin fibroblasts and the effect of antioxidants. We found that significant HSP70 induction occurred after exposure to HOOH and this was associated with marked perturbation in protein and nonprotein SH groups and with a considerable increase in protein carbonyl levels. Treatment with a natural antioxidant from rosemary extract provided notable protection against stress-induced modifications of cellular SH and carbonyl content, maintaining functional levels of cytoprotective heat shock protein 70. Our results point to the possible involvement of redox mechanisms in the heat shock signal transduction pathway, which may play an important regulatory role in the genetic mechanisms of tolerance to oxidative stress. Exogenous supplementation of an antioxidant hydrophilic extract from rosemary could have cosmetic benefits and may represent an efficient tool to minimize free radical-induced skin damage.

Antioxidants↗
PubMed2001

[Multislice spiral CT angiography in the evaluation of the anatomy of splanchnic vessels: preliminary experience].

PURPOSE: The aim of this study was to optimize the protocol for multislice spiral CT angiography and to assess the ability of the technique to detect the anatomy of splanchnic vessels, using volume rendering as reconstruction algorithm. MATERIAL AND METHODS: The anatomy of splanchnic vessels was studied in 19 patients (11 men, 8 women, age range 38-83 years) undergoing CT of the abdomen and pelvis. All examinations were performed with a multislice spiral CT scanner (Somatom Plus 4 Volume Zoom; Siemens, Erlangen, Germany) using the following parameters: collimation, 1 mm; slice width, 1 mm; table feed, 8 mm/sec; reconstruction interval, 1 mm; mAs, 120; kVp, 120. Before the study, the patients received 800 ml of water as oral contrast agent to opacify the stomach and small bowel. A nonionic contrast medium (130-140 ml; Xenetix 350, Guerbet, Aulnay-Sous-Bois, France) was infused intravenously at a rate of 3-5 ml/sec. Two scans of the abdomen and pelvis were obtained at 20-25 sec (arterial phase) and 60-65 sec (venous phase) after starting contrast medium injection. Image elaboration was performed using Vitrea 2.2 (Vital Images; Minneapolis, Minn., USA), a software with volume-rendering capabilities. RESULTS: All major arterial (celiac trunk, superior mesenteric artery, and inferior mesenteric artery) and venous (portal vein, superior mesenteric vein, inferior mesenteric vein, and splenic vein) vessels could be evaluated with excellent detail in all patients. Side branches, including small collaterals, could also be easily visualized. Volume rendered images always provided better understanding of the 3D anatomic relationships among splanchnic vessels and surrounding organs. DISCUSSION AND CONCLUSIONS: Multislice spiral CT angiography allows for optimal depiction of the anatomy of splanchnic vessels. It can be anticipated that the clinical applications of this imaging modality in the study of splanchnic vessels will be greatly expanded. However, further studies are necessary to rigorously compare the results of multislice spiral CT angiography with conventional angiography in terms of diagnostic accuracy.

Adult↗
PubMed2001

Ash Split Cath in geriatric dialyzed patients.

Vascular access is the essential step in performing hemodialysis in uremic patients. In the absence of a permanent and utilizable native arterio-venous fistula, the use of a tunnelled catheter makes dialysis therapy possible. The Ash Split Cath, a recently introduced chronic hemodialysis catheter, was inserted in five patients (7.1% of our prevalent dialysis population) because of repeated venous thrombosis in three patients and a poor venous tree in two. The mean age of patients was 78 years +/- 7. The average blood flow rate was 250+/-50 ml/minute and the mean venous pressure 140mm Hg +/- 35. Recirculation determined by low flux technique was less than 2%. KT/V calculated 3 months after the catheter placement was 1.2+/-0.02. During the follow-up we did not document any infection of the exit site or related to the catheter. This device is simple to place, gives adequate dialysis treatment and is useful in geriatric dialyzed patients in whom the arterio-venous fistula can no longer be used.

Aged↗
PubMed2001

Regulation of heat shock protein synthesis in human skin fibroblasts in response to oxidative stress: role of vitamin E.

Skin plays an important role in protection against oxidative stressors such as ultraviolet radiation, ozone and chemicals. Chronic sun exposure causes degenerative changes in the skin that are recognized as photoaging. Oxidative stress has been shown to alter the expression of mammalian antioxidant enzymes as well as to enhance numerous transcription factors, including nuclear factor kappaB, stress-activated protein kinase and heat shock factor This latter is the transcription factor for the synthesis of heat shock proteins, which have been known to protect against a wide variety of toxic conditions, including extreme temperatures, oxidative stress and cytotoxic drugs. In this study we investigated the role of oxidative stress in the induction of heat shock protein (HSP) 70 in human skin fibroblasts and the effect of vitamin E. We found that significant HSP70 induction occurred after exposure to HOOH and that this was associated with a significant perturbation in protein and nonprotein sulfhydryl groups, and with a significant increase in protein carbonyl levels. Treatment with vitamin E conferred significant protection against stress-induced modifications of cellular sulfhydryl and carbonyl content, while maintaining functional levels of cytoprotective HSP70. Our results point to the possible involvement of redox mechanisms in the heat shock signal transduction pathway, which may play an important regulatory role in the genetic mechanisms of tolerance to oxidative stress. Exogenous antioxidant supplementation with vitamin E could have cosmetic benefits and may be an efficient tool to mitigate the consequences of free radical-induced skin damage.

Cells, Cultured↗
PubMed2000

Lamivudine for treating active hepatitis B in renal transplant recipients: a case report.

AIM: Chronic hepatitis B is still a matter of concern among renal transplantation patients and patients waiting for a renal transplant since it influences negatively morbidity and mortality. Morbidity and mortality are associated with HBV replication. Lamivudine is a new antiviral agent whose use has been advocated to treat HBV-infected liver transplanted patients. SUBJECT AND METHODS: Here we present our experience with an HBV-positive kidney-liver transplanted patient treated with lamivudine after transplantation. RESULTS: After lamivudine was started HBV-DNA became negative (chemiluminescence, Digene Hybrid Capture System, USA 1997) and ALT levels returned to normal. After eighteen months and after steroid pulses treatment for acute rejection, HBV-DNA became positive again, probably due to virus mutation. Lamivudine treatment was not withdrawn since it has been suggested that the mutant form might be less pathogenic than the wild one. To this extent, more than 10 months after, our patient is still in a good clinical general condition and still takes lamivudine 75 mg/day. No lamivudine-related side effects were recorded. CONCLUSIONS: Our case confirms that lamivudine is a safe and useful tool in treating renal transplant recipients with chronic hepatitis B.

Hepatitis B↗
PubMed2000

Biochemical studies of a natural antioxidant isolated from rosemary and its application in cosmetic dermatology.

Oxidative damage to DNA, RNA, proteins and cell membranes occurs when the cellular concentration of reactive oxygen species exceeds the capacity of the cell to eliminate them. Aerobic prokaryotic and eukaryotic organisms have developed a set of cell defense systems to mitigate the damaging effects of reactive oxygen species. Epithelial surfaces contain antioxidants that could be expected to provide a defence against environmental stress caused by reactive oxygen and nitrogen species. Skin, which has a highly differentiated and complex structure, is particularly vulnerable to free radical damage because of its contact with oxygen and with other environmental stimuli. Fruit and vegetables contain several classes of compounds that when ingested can potentially contribute to endogenous modulation of antioxidant defences. The purpose of this study was to investigate the effectiveness of a natural extract derived from rosemary to protect free radical-induced skin damage. We provide evidence that an alcoholic extract of rosemary leaves, Rosm1, is endowed with strong antioxidant activity and, as evaluated by both in vitro and in vivo systems, is capable of inhibiting oxidative alterations to skin surface lipids. The present study provides a preclinical perspective on the interface between the biochemical properties of a natural extract isolated from rosemary leaves, a better understanding of the endogenous antioxidant potential of skin and the real validity of natural antioxidant biotechnology in antiaging skin management.

Adolescent↗
PubMed2000

Clinical characteristics associated to atrial fibrillation in chronic hemodialysis patients.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained arrhythmia diagnosed in non-uremic patients and its prevalence increases in older subjects, however, information concerning AF in dialysis patients is scarce. Therefore, we carried out a prospective cross-sectional study from September 1996 to December 1996 in order to evaluate the prevalence and some of the clinical characteristics associated to AF in hemodialysis (HD) patients. SUBJECTS AND METHODS: 316 HD patients (age 63 +/- 12 years, dialysis duration 69 +/- 71 months) treated in three different hospital-based units were studied. Standard 12-lead electrocardiograms (ECGs) carried out in the interdialytic day during the study period were reviewed. Data concerning age, history of ischemic heart disease (IHD), cerebrovascular disease (CVD), peripheral vascular disease (PVD), presence of diabetes, smoking history and antihypertensive therapy were collected. Systolic and diastolic blood pressure, fasting cholesterol and triglycerides, albumin and hemoglobin were also derived from the clinical records. Performance status was assessed by Karnofsky index (Ki). RESULTS: 74 patients (23.4%) had persistent AF, i.e. presence of AF in all (at least two) ECGs performed in the study time. Patients with AF were older (age 69 +/- 10 vs 62 +/- 12 years, p < 0.001), had lower Ki (54 +/- 20 vs 68 +/- 17, p < 0.01), cholesterol (182 +/- 46 vs 198 +/- 52 mg/dl, p < 0.01) and albumin (3.9 +/- 0.5 vs 4.1 +/- 0.5 g/dl, p < 0.001) compared to those with no AF. Prevalence of IHD (44.5% vs 19%, p < 0.05) and PVD (23% vs 11%, p < 0.05) was higher among AF patients. Logistic regression analysis showed that IHD (p < 0.001) and Ki (p < 0.01) were independently associated to AF. CONCLUSION: We conclude that AF is a frequent arrhythmia in HD patients treated in hospital-based dialysis units, especially in those with low performance status. It appears to be associated to the atherosclerotic damage of coronary arterial tree. Prospective studies are necessary to assess whether it could contribute to cardiovascular morbidity and mortality in end-stage renal disease.

Aged↗
PubMed2000

[Optimization of the technique of virtual colonoscopy using a multislice spiral computerized tomography].

PURPOSE: To optimize scanning parameters for virtual colonoscopy utilizing a multislice Helical CT scanner in an in vitro study (using a homemade colonic phantom) and in a preliminary clinical study. MATERIAL AND METHODS: A colonic phantom was built using a plastic tube and 12 plastiline polyps were placed inside. The colonic phantom was studied with a multislice Helical CT scanner. Axial images were obtained with the phantom parallel to the long axis of the moving table (in order to simulate the evaluation of ascending and descending colon): oblique images were acquired with the phantom at 45 degrees relative to the long axis of the moving table (in order to simulate the evaluation of sigmoid colon and colonic flexures). Four different scanning protocols were tested: 1) slice collimation, 5 mm; slice width, 7 mm; table speed, 25 mm; reconstruction index, 5 mm; 2) slice collimation, 2.5 mm; slice width, 3 mm; table speed, 15 mm; reconstruction index, 3 mm; 3) slice collimation, 1 mm; slice width, 1.25 mm; table speed, 5 mm; reconstruction index, 1 mm; 4) slice collimation, 1 mm; slice width, 1.25 mm; table speed, 4 mm; reconstruction index, 1 mm. Quantitative analysis consisted in evaluation of the number of identified polyps and polyp size along the longitudinal axis. Qualitative analysis consisted in the evaluation of image artifacts and quality of 3D reconstructed images (step artifacts and polyp geometry distortion). This preliminary clinical study was performed in 12 patients (7 men and 5 women) who underwent multislice Helical CT colonography. We selected patients with clinical indications for conventional colonoscopy or after unsuccessful conventional colonoscopy. RESULTS: Multislice Helical CT colonography was 100% sensitive in the detection of all polyps and in all scanning protocols. With oblique scans, only a 3-mm polyp was missed during protocol 1 (sensitivity: 92%). Polyp geometry distortion was observed on longitudinal reconstructions, whereas no distortion was seen on axial images. Image quality was graded as optimal for protocols 2, 3, and 4; protocol 1 was graded as good on transverse scans and as poor on oblique scans. In our preliminary clinical study, two colonic carcinomas and three polyps were identified. CONCLUSIONS: At present, the introduction of multislice technology in virtual colonoscopy permits to improve spatial resolution and image definition. The actual clinical advantage, in terms of increased diagnostic accuracy, needs further investigation in larger clinical studies.

Artifacts↗