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Biomedical subjects

F Antonucci

Publications and source records attributed to F Antonucci.

51 records · Page 3Linked to original sources

Serum trypsin-like immunoreactivity and secondary hyperparathyroidism in renal failure.

UNLABELLED: In 46 kidney patients aged from 30 to 71 years, after an overnight fast, serum levels of trypsin (TLI), gastrin (Gas), parathromone (PTH), calcium (Ca), magnesium (Mg), phosphate (iP), amylase, were evaluated. Ten patients had a normal renal function; in 18 patients glomerular filtration rate (GFR) ranged from 5 to 70 ml/m'; 18 patients with GFR below 2 ml/m' were treated with 4 hours hemodialysis. In dialysed patients TLI was evaluated before and after dialysis. In patients with FGR ranging from 120 to 5 ml/m' a significant inverse correlation (p < 0.001) appeared between TLI and GFR values. In the same group a significant direct correlation (p < 0.001) was found between PTH and TLI. The study showed also a significant direct correlation between amylase and TLI (p < 0.001); likewise TLI, amylase was inversely correlated to GFR (p < 0.01) and directly to PTH (p < 0.001). No correlation was found between TLI and Gas, Ca, Mg, iP. A significant inverse correlation was found between PTH and GFR (p < 0.01). Because serum level of PTH, amylase and TLI were related to GFR values, we calculated partial correlation between these parameters. The partial correlation coefficients of the relation between PTH and TLI, PTH amylase, holding GFR constant, were higly significant (p < 0.001). On the contrary, holding a constant PTH, the correlations between pancreatic enzymes and GFR were not confirmed. Pre-dialysis TLI levels were significantly higher than post-dialysis (p < 0.05). IN CONCLUSION: 1) TLI and amylase have the same behaviour in renal failure; 2) the levels of both enzymes are high in renal insufficiency; their values seem to be correlated to secondary byperparathyroidism.

Adult↗

Gastric acid secretion, calcitonin and secondary hyperparathyroidism in uremic patients undergoing regular dialysis therapy (RDT).

Fortyseven uremic patients on RDT underwent a gastric secretion study and a contemporary evaluation of serum levels of Calcium (Ca), Phosphate (iP), Magnesium (Mg), Alkaline Phosphatase (AP), immunoreactive gastrin (Gas), parathyroid hormone (PTH), calcitonin (CT). Secretory test (pentagastrin 6 microgram/kg) was performed in the morning, after 12 hours of fasting, in the interdialytic interval. Female patients, male patients on RDT from less 1 year and hyposecretor patients were excluded from the study. On the basis of these criteria 25 normal or hypersecretor males between 20 and 55 years old were selected. A significant positive correlation was found between PTH and CT, while a negative significant correlation was found between CT and BAO and CT and PAO. Similarly, a significant negative correlation was found between PTH and BAO and PTH and PAO. Multiple regression study showed that the negative influence of CT on BAO and PAO is more relevant than the positive influence of PTH. These data suggest that PTH and CT are involved in gastric acid secretion in uremia. Since the inhibitory effect of CT is prevailing on the stimulating effect of PTH, patients with higher levels of PTH and CT have a lower gastric acid secretion. CT might therefore be considered as a protective factor against hypersecretion in uremia.

Adult↗

Historical overview on the development and characteristics of stents and future outlooks.

The history and development of endovascular stents is described beginning with the Maass double helix spiral prosthesis, the first stent used in human clinical trials in the early 80s. This is followed by a description of the three main groups of stent techniques: the shape memory alloy stents, the balloon-expandable stents, and the self-expanding stainless steel stents. Requirements and new trends for improving clinical results in the future complete this text.

Blood Vessel Prosthesis↗

Use of the Wallstent in the venous system including hemodialysis-related stenoses.

Eighteen patients with a total of 23 venous stenoses or occlusions were treated with the Wallstent. In 5 patients treated for malignant stenosis there was one primary failure due to insufficient stent expansion. The other 4 patients showed rapid relief of their inflow obstruction, all remaining asymptomatic despite later stent occlusion in 1 patient. Four patients were treated for benign postoperative stenoses of the iliac or femoral vein. All stents remained patent for a period of 6 weeks-58 months. Nine patients were treated for one or multiple stenoses along the venous outflow tract of hemodialysis fistulas. Of 14 lesions that were eventually stented, 12 are still patent after 3-27 months (mean 19). However, 10 secondary interventions (eight percutaneous transluminal angioplasty (PTA), two stents) and three additional stent procedures for new lesions were necessary. Although our experience is limited, we believe that patients with tumor compression or postoperative strictures of large veins benefit from treatment with stents. Stenting of venous outflow stenoses in hemodialysis fistulas can significantly prolong stent function, however, PTA should always be the first treatment of choice.

Arteriovenous Shunt, Surgical↗

Malignant biliary obstruction: treatment with self-expandable stainless steel endoprosthesis.

Metal endoprostheses of the Wallstent type were successfully inserted percutaneously and endoscopically in 80 consecutive patients with malignant obstructive biliary stenoses, who were followed for up to 18 months. The indication for treatment was jaundice due to malignant biliary obstruction. Repeat radiological investigations were performed if the patient had symptoms suggesting stent occlusion. After stent implantation, 88% of patients demonstrated a serum bilirubin decrease by more than 50%. We observed a 15% rate of serious complications, including a 10% rate of cholangitis with septicemia. There were no cases of stent migration or occlusion due to encrustation of bile. Recurrent jaundice occurred in 17.5% of patients due to progressive tumor growth after 3-10 months. In 5 of these patients, tumor overgrowth was redilated and/or restented. Of the 80 patients, 34% are alive after 2-12 months (mean: 242 days); of these, two-thirds are free of jaundice. Sixty-six percent of patients died between 3 days and 1.5 years (mean: 133 days). Although autopsy investigations revealed the possibility of tumor growth onto the inner surface of the stent, through the mesh of the endoprosthesis, no stent occlusion by tumor ingrowth into the lumen occurred. Self-expandable stainless steel endoprostheses provide good palliation in patients with malignant obstructive jaundice.

Adenoma, Bile Duct↗

Hemodialysis related venous stenoses: treatment with self-expanding endovascular prostheses.

Seven patients undergoing chronic hemodialysis presented a total of ten venous stenoses which were treated with self-expanding metallic vascular endoprostheses. Four lesions were central (brachiocephalic and subclavian vein). One acute occlusion could be successfully recanalized by PTA. Restenosis prompted seven secondary interventions. Four patients underwent a kidney transplantation between 5 and 8 months after vascular stenting. Definite occlusion occurred in one patient. According to our experience, stenting of large central veins in hemodialysis patients seems less prone to restenosis due to intimal hyperplasia. Despite a high restenosis rate in the peripheral lesions we believe that stenting is a useful tool in the treatment of hemodialysis-related venous stenosis, permitting a significant prolongation of shunt function.

Adult↗

Metallic stents in malignant biliary obstruction: results of a multicenter European study of 240 patients.

PURPOSE: In this retrospective multicenter study, the authors analyzed the clinical efficacy of different metallic stents in the palliative treatment of patients with neoplastic obstructive jaundice. PATIENTS AND METHODS: Two hundred forty patients were treated in four European centers. Causes of obstruction were pancreatic carcinoma (n = 84), biliary neoplasm (n = 99), metastases in hilar nodes (n = 34), primary or secondary liver tumors (n = 4), and other tumors (n = 19). A total of 388 metallic stents were used: 300 Wallstents, 35 nitinol Strecker stents, 40 Gianturco-Rosch Z stents, and 13 tantalum Strecker stents. RESULTS: Overall 25- and 50-week survival rates were 42% and 16%, respectively; the 30-day mortality rate was 14.6%. Two deaths were related to the procedure (0.8%); 19 patients (8%) had major complications. The 25-week patency rate was significantly higher for the nitinol Strecker stents and the Wallstents (78% and 67%, respectively) than for the Z stents and the tantalum Strecker stents (30% and 20%, respectively) (P < .01 and P < .001, respectively). Average patency was 8.3, 5.9, 2.3, and 4.0 months, respectively. Reintervention due to stent obstruction was necessary in 53 patients. CONCLUSION: The Wallstent and the nitinol Strecker stents were the most effective in achieving long-term palliation. Patency was significantly affected by the level of obstruction but not by the type of obstructing tumor.

Aged↗

Vascular endothelial growth factor (VEGF) and VEGF receptors in diabetic nephropathy: expression studies in biopsies of type 2 diabetic patients.

Vascular endothelial growth factor (VEGF) is involved in the pathogenesis of diabetic retinopathy but its role in diabetic nephropathy is only speculative so far. It has been shown that in renal cortex of normal kidneys, glomerular and tubular epithelial cells express VEGF and that VEGF 165 is the predominant isoform. Two VEGF receptors, KDR (kinase domain region) and Flt-1 (fms-like tyrosine kinase) are co-expressed by glomerular and peritubular capillary endothelial cells. However, VEGF and VEGF receptors are predominantly expressed at glomerular level. We recently demonstrated that in type 2 diabetic patients glomerular qualitative and quantitative changes of VEGF mRNA expression are associated with functional and structural renal changes. In the present work we focused on the tubulo-interstitial compartment; by reverse transcription/polymerase chain reaction (RT/PCR) we evaluated the expression of VEGF, KDR, Flt-1 and the relationship between the two main type of VEGF isoforms, VEGF121 and VEGF165 in the tubulo-interstitium of type 2 diabetic patients. Patients were divided in three category on the basis of renal structure pattern: CI, with normal or near normal renal structure; CII, with glomerular and tubulo-interstitial lesions occurring in parallel (typical diabetic nephropathology); CIII, with atypical pattern of renal injury, i.e., more severe tubulo-interstitial and vascular than glomerular changes. Comparison between the two cortical compartments revealed that, both in glomeruli and in tubulo-interstitium. VEGF121 isoform exceed VEGF165 while Flt-1 was significantly lower in glomeruli. CIII patients had the lowest tubulo-interstitial level of VEGF and Flt-1 mRNAs. These results suggest that the transcriptional shifting from VEGF165 to VEGF121 isoform and the unbalanced FIt-1 expression between tubulo-interstitium and glomeruli could be involved in the pathogenesis of diabetic nephropathy. Furthermore, at least in CIII patients, down-regulation of the VEGF-Flt-1 system could be involved in the mechanisms leading to tubulointerstitial diabetic lesions.

Adult↗

[The Dialysis Outcomes and Practice Patterns Study (DOPPS): results of the Italian cohort].

BACKGROUND: The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective, longitudinal, observational study examining the relationship between dialysis unit practices and outcomes for hemodialysis (HD) patients in seven developed countries France, Germany, Italy, Spain, United Kingdom, Japan and the United States. Results of the DOPPS in Italy are the subject of this report. METHODS: A national representative sample of 20 dialysis units (21 in Germany) was randomly selected in each of the European DOPPS countries (Euro-DOPPS). In these units, the HD in-center patients were included on a facility census, and their survival rates continuously monitored. A representative sample of incident (269 in Italy, 1553 in the Euro-DOPPS) and prevalent (600 in Italy, 3038 in the Euro-DOPPS) patients was randomly selected from the census for more detailed longitudinal investigation with regard to medical history, laboratory values and hospital admission. RESULTS: Comparing the Italian and Euro-DOPPS cohorts we found comparable mean age for prevalent patients (61.4 vs. 59.5 yrs), but incident patients were older in Italy. Italian prevalent patients had less cardiovascular disease, more satisfactory nutritional status and more frequent use of native vascular access. These data were associated with a comparable mortality (15.7 vs. 16.3 deaths/100 patient yrs), but morbidity was lower in Italy. Kt/V levels were comparable in the two cohorts (1.32 vs. 1.37), but 35% of Italian patients showed a Kt/V below the recommended target. Moreover, hemoglobin levels were below 11 g/dL in 60% of Italian patients. CONCLUSIONS: The DOPPS results bring to light several positive aspects and the opportunity for further possible improvements for Italian patients, but at the same time highlight some critical points that could represent a risk for dialysis quality.

Aged↗

[Atheroembolism: a form of systemic vascular disease].

Atheroembolism, a systemic vascular disease. Cholesterol crystal embolization (CCE) is an infrequent but serious disorder that is often an unrecognized medical problem. CCE may occur spontaneously from eroded atherosclerotic plaques or most frequently following procedures such as angiography, angioplasty, cardiac catheterization, anticoagulant therapy and aortic surgery. CCE predominantly affects elderly males with a frequent history of hypertension, atherosclerotic vascular diseases and renal insufficiency. CCE may result in protean clinical manifestations and may produce a spectrum of functional impairment. Confusion over the disease's natural history arises because the difficulty of establishing an antemortem diagnosis, and because the laboratory findings are non-diagnostic and non-specific. The mortality was 81% and the causes of death was most often due to multiorgan failure especially renal involvement. The definitive diagnosis depends upon finding the presence of intravascular cholesterol crystal in biopsy or autopsy specimens. The skin, muscle and kidney were the three most common sites for obtaining a premortem diagnostic biopsy.

Arteriosclerosis↗