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Biomedical subjects

R Alfieri

Publications and source records attributed to R Alfieri.

At least 19 recordsLinked to original sources
PubMed2026

The role of circulating tumor DNA (ctDNA) to detect minimal residual disease in locally advanced gastroesophageal carcinoma: the BUTTERFLY study.

BACKGROUND: Despite advances in perioperative and neoadjuvant strategies, patients with locally advanced gastroesophageal cancers remain at high risk of recurrence after curative intent treatment. No validated biomarkers are available to detect minimal residual disease (MRD) or to guide post-operative risk-adapted management. Circulating tumor DNA (ctDNA) has emerged as a noninvasive tool for disease monitoring; single-parameter or tumor-informed assays, however, may lack sensitivity in low-tumor burden settings. Multimodal, tumor-agnostic approaches may overcome these limitations. METHODS: The BUTTERFLY study is a prospective, multicenter observational study enrolling patients with stage II-III gastric, gastroesophageal junction, or esophageal cancer treated with perioperative chemotherapy or neoadjuvant chemoradiotherapy followed by surgery. It evaluates the diagnostic performance and prognostic value of an academic, tumor-agnostic, multimodal ctDNA assay for MRD detection and prognostic stratification. Serial plasma samples are collected from baseline through post-operative follow-up and at relapse. Cell-free DNA is analyzed using the Agnostic Liquid Biopsy Multimodal Advancement (ALMA) platform, integrating tumor fraction estimation, somatic copy number alterations, fragmentomic features, single-nucleotide variants, and whole-genome methylation profiling. Multimodal features are combined with clinical variables using machine learning-based models to enhance MRD detection and relapse risk stratification. The primary endpoint includes sensitivity and specificity of ALMA-defined ctDNA/MRD status at the 4-8 weeks after surgery landmark, whereas secondary endpoints assess diagnostic performance at other time points and associations between ctDNA status and dynamics with disease-free survival, overall survival, treatment response, and lead time to recurrence. FUTURE PERSPECTIVES: If validated, this tumor-agnostic, multimodal ctDNA approach may enable earlier molecular relapse detection and support personalized post-operative management strategies.

circulating tumor DNA (ctDNA)↗
PubMed1992

Serum beta 2-microglobulin levels and p24 antigen, lymphocyte depletion and disease progression in human immunodeficiency virus infection.

Abnormally elevated serum beta 2-microglobulin levels have been associated with progression of human immunodeficiency virus disease. In this study we have analyzed the relationship between serum beta 2-microglobulin levels of patients at different stages of the disease and serological and immunological parameters commonly used for monitoring the infection. The investigation was performed on 150 patients and 30 controls during the period from March 1989 to March 1990. At that time, 30 patients had the acquired immunodeficiency syndrome or its related complex and 120 had persistent generalized lymphadenopathy or were asymptomatic. Thirty-nine antibody-negative subjects, belonging to a high-risk group for the acquired immunodeficiency syndrome, were used as controls. All patients had normal renal function. There was a significant relationship between increased serum beta 2-microglobulin levels and the presence of p24 antigen, a decrease in the total number of lymphocytes (less than or equal to 1500/mm3) and a decrease in CD4+ T lymphocytes (less than or equal to 200/mm3). No significant relationship between serum beta 2-microglobulin levels and CD3+ T lymphocytes was found.

Adolescent↗
PubMed1992

Glucagon-independent renal hyperaemia and hyperfiltration after an oral protein load in Child A liver cirrhosis.

The work was designed to study the effects of a meat meal on glomerular filtration rate (GFR), renal plasma flow (RPF), and plasma concentrations of glucagon, insulin, growth hormone, renin, aldosterone, total amino acids, and NH3 in healthy humans (H) as well as in patients with Child A liver cirrhosis (LC). The meat meal produced renal hyperaemia and hyperfiltration without changes in the filtration fraction. Fractional Na excretion in urine increased significantly after the meat meal only in LC. Hyperinsulinaemia and hyperglucagonaemia were seen at baseline in LC and were not affected by the meat meal, whereas in H glucagon concentration increased significantly over baseline within 30 min from the meat meal and insulin within 60 min. Growth hormone concentration was normal at baseline in LC and increased significantly 120-180 min after the meal, whereas it was not affected in H. Renin and aldosterone were stable in both H and LC. Plasma amino acid concentration began to increase 60 min after the meat meal, when hyperfiltration was present. The data indicate that in human Child A cirrhosis of the liver renal haemodynamic response to a meat meal is independent of changes in glucagon.

Dietary Proteins↗
PubMed1991

Lithium clearance in patients with chronic renal failure.

Lithium clearance (CLi) was studied in the healthy subjects (H) and in patients with chronic renal failure (CRF) with a mean GFR of 36.08 +/- 3.8 ml/min x 1.73 m2 in order to evaluate (1) the variability of CLi measurements; (2) the changes of CLi during the hyperfiltration response to a meat meal (2 g/kg b.w. of protein), and (3) the effects on CLi of different protein intakes. CLi correlated with GFR and with urinary sodium, FeLi correlated with FeNa in H and CRF. The intraindividual standard deviation (IISD) of GRF, CLi and FeLi assessed in triplicate studies in the course of a single experiment averaged 4.70, 7.15 and 10.69% in CRF and 1.77, 4.09 and 4.61% in H. When IISD for GFR, CLi, and FeLi was assessed in triplicate measurements in the course of 3 studies performed at 1-week intervals (day 1, day 8, day 15), it averaged 7.36, 9.21 and 15.72% in CRF and 1.83, 5.08 and 5% in H. During the hyperfiltration response to a meat meal, CLi and FeLi did not change in CRF and increased significantly in H. In 10 patients with CRF who were switched for 3 weeks from a protein intake of 0.85 g/kg to a protein intake of 0.60 g/kg, GFR was significantly (p less than 0.001) reduced by 29%, while CLi was stable. The data indicate that because of its variability, CLi is of little use in experiments designed to study subtle changes in renal Na transport.

Adult↗
PubMed1991

Renal hemodynamics, plasma amino acids and hormones after a meat meal in progressive nephron loss.

Ten patients with chronic renal failure (GFR 29-97 ml/min), on free diets providing 1 g/kg B.W. of proteins, ingested an oral protein load (meat meal, 2 g/kg B.W.). GFR and RPF increased significantly over baseline with no change in filtration fraction. Within 30 min of the meal and for the next 3 h a statistically significant increase was observed in the plasma concentrations of the following amino acid groups: essential, non-essential, total, branched-chain, ketogenic, glycogenic, glycogenic and ketogenic, basic, acid, polar and non-polar. At 30 min the smallest increase was seen in acid and polar amino acids (6.7% and 7.6%, respectively). At 180 min the largest increase (78.8%) was seen for glycogenic and ketogenic amino acids and total plasma amino acids were 1.58 times baseline. After the meat meal plasma glucagon and insulin rose significantly, while growth hormone, plasma renin activity and aldosterone did not vary.

Adult↗
PubMed1987

The design of transverse filters and their use in visual electrograms.

The subject under study is a digital filtering method which combines the advantages of both theoretical precision and great flexibility of use. This method has enabled us to develop transverse filters which respect the principle of causality and offer a fast and simple solution in the filtering of electrophysiological potentials. Here we present both the design of transverse filters and their application to visual electrophysiological signals.

Electroretinography↗
PubMed1987

Protein balance during very-low-calorie diets for the treatment of severe obesity.

Very-low-calorie diets (less than 500 kcal/day; VLCD) are widely used for the treatment of severe obesity. We report the effects of such diets, consisting of proteins only or proteins and carbohydrates (CH), on nitrogen balance and protein nutritional status of morbidly obese patients. Cumulative nitrogen loss, serum albumin, transferrin, prealbumin (PA) and retinol-binding protein (RBP) concentrations, and plasma amino acid profile were determined in two groups of obese patients: 5 subjects (3 women, 2 men: BMI 55.3 +/- 2.2 kg/m2) subjected for 4 weeks to a protein VLCD (40 g protein + 2 g fat) and 7 others (4 women, 3 men: BMI 45.6 +/- 2.8 kg/m2) received for the same length of time a protein + CH VLCD (34 g protein + 26 g CH). Nitrogen balance was determined weekly whilst plasma and serum variables were measured on days 0, 3, 5, 10, 20 and 28 of treatment. Nitrogen balance did not significantly differ between the two groups of patients throughout the treatment. Serum PA and RBP concentrations decreased from day 5 and day 10, respectively, in both groups. Plasma amino acids showed a similar pattern in the protein and protein + CH groups. Alanine gradually decreased below baseline values; after a peak value on day 5, branched-chain amino acids (valine, leucine, isoleucine) returned to baseline values in both groups. In conclusion, in severely obese patients subjected to VLCD, nitrogen balance, labile protein concentrations and plasma amino acid profile are not significantly affected by adding CH to proteins.

Adult↗
PubMed1977

[Anthropometric state of nutrition in students of various elementary and secondary schools in Ancona].

An anthropometric assessment was made of the nutritional state of children from Ancona elementary and middle schools. It was found that the girls had more body fat than the boys, though the latter, too, displayed values above those reported in U.S. and Italian studies. The view is expressed that this excess fat requires counteraction through nutritional education. Diet and physical exercise are known to be important in the prevention of degenerative diseases of a metabolic nature. Such prevention must be undertaken as soon as possible.

Adipose Tissue↗