Search PubMed⌕ Search

Biomedical subjects

G Como

Publications and source records attributed to G Como.

At least 19 recordsLinked to original sources
PubMed2006

Ultrasonographic analysis in vitro of parietal thickness of lower limb varicose veins.

PURPOSE: The aim of this study was to evaluate the ability of ultrasound (US) to measure the parietal thickness of varicose veins. MATERIALS AND METHODS: In a blind in vitro analysis, 28 great saphenous veins, obtained after stripping surgery from 28 patients with chronic venous insufficiency, were examined with a digital US scanner ATL-HDI5000, linear 5-1 to 2-MHz broadband probe, compound imaging technique and analogic-digital zooming. We obtained one to three progressive measurements for each vein wall (total 67 parietal thicknesses). The samples, fixed in formalin, were sent to the pathology laboratory: sections were obtained at the same level of the sonographic planes, and images were obtained by digital camera mounted on an optical microscope. Measurements obtained at histology were considered as the gold standard. K-statistic was applied to compare sonographic and histologic measurements. RESULTS: Considering only the hypoechoic wall portion, 29/29 (100%) diagnoses of hypotrophy (K=0.91), 19/22 (86%) diagnoses of normotrophy (K=0,47) and 12/16 (75%) diagnoses of hypertrophy (K=0.7) were obtained by sonography. CONCLUSIONS: In our preliminary experience, the in vitro study of varicose veins allows precise, at least morphological, detection of hypotrophic walls. If these preliminary data are confirmed in vivo, sonography could be used to discriminate patients eligible for conservative treatment instead of surgery.

Adult↗
PubMed2006

Multidetector CT with double arterial phase and high-iodine-concentration contrast agent in the detection of hepatocellular carcinoma.

PURPOSE: The purpose of this study was to determine whether the double arterial phase with multidetector computed tomography MDCT and high-iodine-concentration contrast material (CM) improves identification of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: Fifty patients with 111 HCC foci (61 confirmed histologically, 46 confirmed by percutaneous interventional procedures, four confirmed by CT follow-up of at least 6 months) underwent MDCT with a double arterial phase and a portal venous phase after administration of contrast material with a high iodine concentration (400 mgI/ml, 2 ml/kg, 5 ml/s). Two radiologists independently evaluated the images in three distinct reading sessions (early arterial phase (EAP), late arterial phase (LAP) and double arterial phase) to determine presence, number and degree of suspicion of HCC. The sensitivity and the positive predictive value (PPV) were calculated for every reading session. The following statistical evaluations were used: k statistic and McNemar's test. RESULTS: Mean sensitivity and PPV in the detection of HCC were, respectively, 83.8% and 93.5% for EAP, 90.5% and 94.8% for LAP, and 94.1% and 95.1% for the double arterial phase. Sensitivity of the double arterial phase was statistically higher when compared with EAP alone but showed no statistically significant difference when compared with LAP. The k values ndicated moderate-to-excellent interobserver agreement in all reading sessions. CONCLUSIONS: Sensitivity and PPV increase progressively when passing from EAP to LAP to double-arterial-phase images obtained with contrast material with a high iodine concentration. However, the difference in sensitivity between LAP and the double arterial phase was not statistically significant.

Adult↗
PubMed2005

De novo HCV infection among dialysis patients: a prospective study by HCV core antigen ELISA assay.

BACKGROUND: Dialysis patients remain a high-risk group for hepatitis C virus infection. The current diagnosis of hepatitis C virus in dialysis patients includes serological measurement of anti-hepatitis C virus antibody; however, nucleic acid amplification technology for assessing hepatitis C virus viraemia is commonly used in other populations. An enzyme-linked immunosorbent assay test for detecting antibody to hepatitis C nucleocapsid core antigen (hepatitis C virus core antigen) in human serum has been recently developed (hepatitis C virus Core Antigen enzyme-linked immunosorbent assay test). It is conceived for screening of donor blood products to significantly reduce the 'serologic window' occurring before seroconversion during acute hepatitis C virus. AIM AND METHODS: A cohort (n = 72) of patients on maintenance haemodialysis in a single unit in the years 2000-2003 was included. Study patients were tested monthly by hepatitis C virus Core Antigen enzyme-linked immunosorbent assay in a prospective, clinical trial. Routine results obtained by hepatitis C virus Core Antigen enzyme-linked immunosorbent assay test were confirmed by assessing hepatitis C virus viraemia by branched-chain DNA (bDNA) signal amplification assay. RESULTS: De novo hepatitis C virus infection was identified in three patients during the study period; the hepatitis C virus incidence was 1.38% (95% confidence intervals, 1.31-4.09) per year. In each patient, hepatitis C virus core antigen testing allowed the serological identification of acute hepatitis C virus before anti-hepatitis C virus seroconversion. Hepatitis C virus RNA testing confirmed the results obtained by hepatitis C virus Core Antigen enzyme-linked immunosorbent assay in all cases. The time from initial hepatitis C virus detection by hepatitis C virus Core Antigen Assay and anti-hepatitis C virus seroconversion was not greater than four weeks. Two (67%) of three patients with de novo hepatitis C virus acquisition were HBsAg negative; both these patients underwent an initial phase of hepatitis C virus viraemia that was associated with an increase in alanine aminotransferase activity and preceded the seroconversion to anti-hepatitis C virus antibody. Nosocomial transmission of hepatitis C virus between haemodialysis patients was implicated in at least two (67%) of these three patients. CONCLUSIONS: Serological testing for hepatitis C virus core antigen can identify acute hepatitis C virus infection before anti-hepatitis C virus seroconversion. The time from initial hepatitis C virus detection by hepatitis C virus core antigen assay and anti-hepatitis C virus seroconversion was not >4 weeks. De novo acquisition of hepatitis C virus in haemodialysis was associated with a rise in alanine aminotransferase levels. Hepatitis C virus core antigen enzyme-linked immunosorbent assay test results can be obtained in routine laboratories without the need of special equipment or training. Hepatitis C virus core antigen testing among anti-hepatitis C virus negative patients on maintenance dialysis is suggested in order to early assess de novo hepatitis C virus within dialysis units.

Acute Disease↗
PubMed1999

Folate measurements in patients on regular hemodialysis treatment.

Patients on regular hemodialysis treatment may develop megaloblastic anemia caused by folate deficiency, but whether folate supplementation is required is still controversial, particularly during erythropoietin administration. Erythrocyte folate concentration is a better indicator of folate status than serum folate, although the latter is the variable generally measured. We measured serum and erythrocyte folate in blood samples from 112 regular hemodialysis patients (57 men, 55 women, 50 treated with erythropoietin, and 62 not) by Stratus Folate immunoenzymatic assay (Dade). Patients with very low serum (<2.87 ng/mL) but normal erythrocyte folate were reinvestigated 4 months later without receiving folate supplementation meanwhile. Serum folate concentrations were 0.48 to 12.76 ng/mL (median, 3.40) and erythrocyte folate 0.19 to 1.85 microg/mL (median, 0.42). Only 37% serum folate values were in the relevant reference interval compared with 80.2% erythrocyte folate values (3.08 to 17.65 ng/mL and 0.24 to 0.64 microg/mL, respectively). A significant correlation was found between serum and erythrocyte folate concentrations, without clinical relevance caused by the wide scatter around the regression line. Serum and erythrocyte folate did not vary significantly between patients given erythropoietin and those not so treated. The folate status of the 24 patients with very low serum folate was almost unchanged 4 months later. According to the serum folate test, 63% of patients needed folate supplementation, whereas the erythrocyte folate test, a better indicator of folate status, suggested that only 1.8% of patients needed folate supplementation. Erythropoietin therapy appears not to be an indication for standard folate supplementation in hemodialysis patients.

Adult↗
PubMed1997

Hepatitis G virus infection in hemodialysis patients.

The increased risk of hemodialysis patients for infections sustained by hepatitis viruses is likely to extend to a newly discovered parenterally transmitted virus, HGBV-C/HGV, able to cause acute and chronic hepatitis. The aim of this study was to assess the prevalence and clinical relevance of this infection in Italian hemodialysis patients. Nineteen of 100 patients (19%) on maintenance hemodialysis were viremic for HGBV-C/HGV, and all of them were infected with a HGV-like genotype. Eight of these patients were coinfected by hepatitis B or hepatitis C viruses. A clinical picture of chronic hepatitis was not appreciable in patients with isolated HGV infection and the presence of HGV did not appear to modify the clinical course of hepatitis B and hepatitis C infections.

Adult↗
PubMed1995

High prevalence of a rare hepatitis C virus in patients treated in the same hemodialysis unit: evidence for nosocomial transmission of HCV.

Hepatitis C virus (HCV) is a major cause of hepatitis among patients treated with maintenance hemodialysis. Blood transfusion appears to be the primary risk factor, but nosocomial transmission of HCV in the dialytic environment has been hypothesized. We addressed this issue by analyzing the individual variation of genomic sequences of HCV in 28 patients on chronic hemodialysis (HD) from the same department and 25 environmentally unrelated patients with HCV-related liver disease. Genome variations of HCV were studied by single strand conformation polymorphism (SSCP) analysis of polymerase chain reaction products obtained from the 5'-untranslated region of the viral genome and by sequence analysis. Six different SSCP patterns were identified in HD patients versus 16 in control patients. Among HD patients the three more frequent SSCP patterns accounted for 85% of observations, while in the control group each pattern was found in 4 to 12% of patients. The ability of SSCP to discriminate sequence variation was proven by sequence analysis which confirmed identity/diversity of sequences selected by SSCP. Moreover, sequence analysis permitted a recognition of the most frequent genome observed in HD patients as a type 4 HCV, which is considered to be rare in the Italian population. The relative homogeneity of HCV variants in HD patients treated in the same HD and the high prevalence in this unit of a rare viral variant support the possibility of a nosocomial transmission of HCV in the dialytic environment.

Adult↗
PubMed1995

Renal effects of dietary supplementation with fish oil in cyclosporine-treated liver transplant recipients.

Nephrotoxicity is the main untoward effect of cyclosporine (CsA) treatment. Experimental and clinical data suggest that dietary supplementation with fish oil may lessen cyclosporine nephrotoxicity, possibly by lowering renal thromboxane (Tx) production. We have studied the renal effects of a daily supplementation for 2 months of 12 g fish oil (18% C20:5 n-3 eicosapentaenoic acid [EPA] and 12% C22:6 n-3 docosahexanoic acid [DHA]) in a placebo-controlled (12 g corn oil), prospective, randomized, double-blind study of stable CsA-treated liver transplant recipients. Thirteen patients ingested corn oil capsules and 13 fish oil. Compliance with dietary regimen was confirmed by fatty acid chromatography that showed increased plasma concentrations of EPA (from 0.4 +/- 0.02% to 4.6 +/- 0.5%, P < .0001) and DHA (from 1.8 +/- 0.2% to 3.9 +/- 0.1%, P < .0001) in the fish oil group and increased plasma concentration of linoleic acid (C18:2 n-6) in the corn oil group (from 25 +/- 2% to 28.4 +/- 2%, P < .001). At the end of the 2 months of the study, in the fish oil group the effective renal plasma flow increased by 22% (P = .012), the glomerular filtration rate increased by 33% (P = .057), the renal blood flow increased by 17% (P = .024), and the calculated total renal vascular resistances decreased by 20% (P = .034). In contrast, none of these parameters changed in the corn oil group. The renal functional reserve determined during L-arginine infusion, plasma renin activity (PRA), and plasma aldosterone (PA) remained unchanged during the study in either group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Effect of gastric acid secretion on intestinal phosphate and calcium absorption in normal subjects.

BACKGROUND: Phosphate-induced hyperparathyroidism still represents an intriguing problem in dialysis patients. Postprandial hyperphosphataemia is considered to be the main stimulus to parathyroid hyperfunction, and therefore many efforts have focused on the use of phosphate binders to prevent phosphate absorption. METHODS: We investigated whether the pH-mediated gastric ionization of calcium phosphate dietary salts is necessary for its intestinal absorption. In eight normal subjects we measured 24-h urinary calcium phosphate excretion and the postprandial blood calcium phosphate profile after a meal containing 1 g of calcium and 2 g of phosphate salts in a crossover placebo-omeprazole study. On two occasions the subjects received either placebo or omeprazole 60 mg/day 2 days before and during the day test. RESULTS: Serum gastrin levels were measured as an indicator of achlorhydria and were 13.7 +/- 1 pg/ml after placebo and 30.4 +/- 4.7 after omeprazole (P < 0.003). Postprandial plasma phosphate profiles were not significantly different between the two studies (+36 +/- 8% after placebo and +24 +/- 8% after omeprazole, NS), while plasma calcium increased by +6.1 +/- 1% after placebo and decreased by -4.2 +/- 0.7% after omeprazole (P < 0.01). The 24-h urinary phosphate excretion was 1068 +/- 85 mg after placebo and 773 +/- 55 after omeprazole (P < 0.002), while the 24-h urinary calcium excretion was 360 +/- 21 after placebo and 238 +/- 15 after omeprazole (P < 0.0001). A negative relationship was observed between absolute changes in plasma gastrin and those in urinary calcium (P < 0.009) and phosphate (P < 0.05). CONCLUSIONS: The inhibition of gastric acid secretion by omeprazole significantly reduces both urinary phosphate and calcium excretion after an oral load. The behaviour of the postprandial calcium-phosphate plasma profile suggests that gastric acid inhibition is more effective in reducing calcium rather than phosphate dietary salts absorption in normal subjects.

Absorption↗
PubMed1994

Validation study of thoracic fluid bioimpedance for assessing the haemodialysis-induced changes in total body fluids.

Thoracic fluid bioimpedance (TFB) has been proposed as a noninvasive technique for monitoring both haemodynamics and fluid homeostasis in patients on regular dialysis. To validate the reliability of TFB in assessing the haemodialysis (HD)-induced changes in plasma volume (PV) in these patients, we examined the changes of TFB during and after HD in relation to those in total plasma protein (TP) concentration, haematocrit (Ht), heart rate (HR), total body water (TBW) and plasma angiotensin II (A-II) concentration. Data were recorded in 13 HD patients with a wide range of interdialytic weight gains before, at the end, and 4, 8, 24, 48 h after the HD session. We found that the percent TFB changes were closely and inversely related with those of TP, Ht and TBW (r = -0.54, r = -0.45 and -0.68, respectively, p < 0.001 for all). Similar relations were found between the percent changes in TFB and those in absolute TP and Ht. In addition, a direct relation was found between the percent changes of TFB and those of HR and of A-II (r = 0.33 and r = 0.31, respectively, p < 0.01 for both). These data indicate that TFB is a reliable method for evaluating the HD-induced changes of intra- and extravascular fluids and, with respect to the conventional techniques, has the advantage of providing this information dynamically, and in conjunction with the haemodynamic data of patients.

Adult↗
PubMed1994

High prevalence of silent gallstone disease in dialysis patients.

Gallstone disease was detected in 28% of 119 patients on regular dialysis treatment. The disease was silent in 82% of the patients. Stones were radiolucent in 88% of the cases, radioopaque in 8% and mixed in 4%. Among 49 variables considered, increasing age was the only variable that correlated significantly with increasing prevalence of gallstone disease. Since no relationships were found between gallstones and age or modes of dialysis, it is conceivable that some mechanism(s) linked with the preexisting chronic nephropathy might have been involved in the development of cholelithiasis. End-stage renal disease could be another so far unrecognized risk factor for cholelithiasis.

Adult↗
PubMed1993

Abnormal hemodynamics and elevated angiotensin II plasma levels in polydipsic patients on regular hemodialysis treatment.

To investigate the cause and the mechanisms responsible of the compulsive thirst and excessive fluid intake observed in many patients on chronic dialysis treatment, we measured plasma antidiuretic hormone (ADH), angiotensin II (Ang II) and some hemodynamic parameters in seven polydipsic and in six normodipsic patients before hemodialysis, at the end of it and several times during the interdialytic interval. Before dialysis we found that ADH was elevated in both groups (6.9 +/- 1.9 vs. 6.9 +/- 1.3 pg/ml, respectively in polydipsics and controls), whereas Ang II was abnormally high only in polydipsics (51 +/- 12 vs. 11 +/- 3 pg/ml, P < 0.01); these patients also had significantly higher heart rate and cardiac indices and lower total peripheral resistances than control patients. Overall these hemodynamic indices were related with Ang II but not with ADH. Ang II rose markedly in polydipsics after dialysis, reaching a peak at the fourth hour after its termination (136 +/- 12 pg/ml) and remained consistently elevated throughout the interdialytic period, whereas in controls Ang II was practically unchanged with respect to baseline. In contrast, ADH had minor and similar modifications in both groups, in whom also the hemodynamic changes were superimposable. Significant correlations were found between the absolute and percent changes of Ang II and those of plasma volume during the interdialytic interval (P < 0.001 for both), and between the individual values of Ang II measured during the whole study and the interdialytic weight gain (P < 0.05). These results demonstrate that polydipsic patients have abnormally high levels of Ang II before and after the hemodialysis-induced volume depletion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Idiopathic membranous nephropathy in the elderly.

In this retrospective non-randomized study we reviewed the outcome for 41 patients with membranous nephropathy older than 65 years at onset and followed for at least 1 year. Twelve of the patients never received any specific treatment (group A), 15 were treated with a 6-month course of methylprednisolone alternated to chlorambucil every other month (group B), and 14 received corticosteroids alone for 3-12 months (group C). At the end of a mean follow-up of 92 +/- 61 months in group A, 53 +/- 35 in group B, and 38 +/- 25 in group C there were significantly more remissions of nephrotic syndrome in group B than in group A (P = 0.035) or in group C (P = 0.010). Moreover patients in group B spent a significantly longer period without nephrotic syndrome than patients in group A (P = 0.000) and C (P = 0.000). Three patients in group A and one in group B died. During the follow-up six patients of group A, two of group B, and five of group C developed renal function deterioration. In patients followed for at least 5 years the mean plasma creatinine increased from a basal of 112 +/- 29 to 239 +/- 287 mumol/l at the 5th year in group A and from 113 +/- 14 to 124 +/- 30 mumol/l in group B. The mean urine protein excretion remained unchanged in group A (basal 4.6 +/- 2.3 versus 4.8 +/- 5.7 g/day at 5 years) while it decreased in group B (from a basal of 6.8 +/- 3.5 to 1.1 +/- 0.4 g/day at 5 years).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Plasma active and inactive renin and fetal complications in women with high risk pregnancies.

To examine whether the activation of the renin system, which occurs during pregnancy, may be relevant for the development and the outcome of the fetus, we measured active and inactive renin throughout gestation in 29 women having a pregnancy defined as "high risk" because of a clinical history of hypertension, nephropathy, and unexplained abortions. In 23 of these women who delivered full-term infants with normal weight and status, we found that active renin increased progressively from early pregnancy until the end of the second trimester and then declined slightly thereafter. In contrast, in the remaining six women who had fetal complications consisting of either signs of distress requiring cesarean section or growth retardation, the increase in active renin failed to occur. In all women the levels of inactive renin were more elevated throughout gestation than those observed in nonpregnant women, and were higher, although not significantly, in women without fetal complications than in those with fetal complications. Thus, a blunted activation of the renin system during pregnancy is associated with alteration in fetal development and may possibly contribute to it.

Adult↗