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Biomedical subjects

S Coppola

Publications and source records attributed to S Coppola.

At least 91 records · Page 5Linked to original sources

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↗

The renal hemodynamic response following a meat meal in children with chronic renal failure and in healthy controls.

The renal hemodynamic response to a meat meal (2 g/kg BW) was studied in 11 healthy children and in 10 children with a mean plasma creatinine concentration of 2.6 +/- 0.1 mg/dl due to chronic renal failure (CRF) of various etiologies. In the healthy status, after a meat meal, the glomerular filtration rate (GFR) increased significantly from a baseline value of 119.0 +/- 5.0 to a peak of 159 +/- 5.8 ml/min x 1.73 m2; in CRF baseline GFR averaged 49 +/- 4.0 and at peak 76.6 +/- 7.2 ml/min x 1.73 m2 (p less than 0.005). The peak GFR response was reached earlier in healthy subjects than in CRF (p less than 0.05) and did not correlate with age or with baseline GFR. Renal plasma flow (RPF) in healthy controls increased from 532 +/- 32 at baseline to 646 +/- 42.9 ml/min x 1.73 m2 after the meal (p less than 0.005). Also in CRF after a meat meal there was a significant increase in RPF from 278 +/- 51 to 65 +/- 66 ml/min x 1.73 m2 (p less than 0.005). The filtration fraction was not affected. The percent increase over baseline values of GFR and RPF at the peak was significantly higher in diseased children. Renal reserve averaged 28.1 +/- 5.3 ml/min in diseased children and 39.7 +/- 5.2 ml/min (p less than 0.01). The data indicate that (1) a meat meal is a suitable method to recruit renal reserve in normal children and in children with chronic renal failure, and (2) the renal reserve is normal in chronic renal failure.

Adolescent↗

Low protein alimentation normalizes renal haemodynamic response to acute protein ingestion in type 1 diabetic children.

The effect of an acute protein load (2 g kg-1 bodyweight [BW]) was studied in nine type 1 diabetic children. Patients were maintained on two different dietary regimens. In study one, patients were on a high protein diet providing from 2.7 to 1.8 g of protein/kg of BW per day. In study two, patients were reevaluated after three weeks of a diet providing from 1.0 to 1.2 g kg-1 of BW per day of protein. In study one (High Protein Diet), we failed to observe any rise in GFR and RPF following the protein meal (137 +/- 21 basal vs. 110 +/- 14 and 472 +/- 93 basal vs. 494 +/- 93 ml/1.73 m2 of SA min-1 at 60 min. This is in contrast with results from seven age matched controls consuming a free diet, which showed a significant rise in both GFR and RPF. In study two (low protein diet), basal GFR was significantly reduced. However after the protein load, both GFR (92 +/- 11 vs. 126 +/- 18 ml/1.73 m2 of SA min-1) and RPF (467 +/- 83 vs. 705 +/- 102 ml/1.73 m2 min-1) rose significantly (P less than 0.05 vs. basal). The data indicate that: 1. short term protein restriction reduces significantly GFR in type 1 diabetic children; 2. diabetic children maintained on an high protein intake show an altered haemodynamic response to protein ingestion; 3. a normal response to protein ingestion can be restored by short term dietary protein restriction.

Adolescent↗

[Radioimmunological determination of HAV and anti-HAV IgA in the feces of patients with acute type-A hepatitis].

58 fecal specimens from 14 patients (10 hepatitis A, 2 hepatitis B and 2 infectious mononucleosis) were tested for the hepatitis A virus (HAV) and IgA anti-HAV by micro-solid-phase-radioimmunoassay. Only patients with hepatitis A were positive for HAV and/or IgA anti-HAV. In the first days of the disease we found HAV in the feces of 4 patients but it was never present after the sixth day. In all hepatitis A we found IgA anti-HAV in at least one fecal specimen and the titer of the antibodies increased in most cases during the course of the disease. The duration and the peak of the IgA response in the feces were strongly similar to other enterovirus infections. Some methodologic improvement both for HAV and IgA anti-HAV detection are suggested.

Adolescent↗

[Markers of viral replication (HBeAg and DNA polymerase activity) in chronic uremia, HBsAg positive, hemodialysis patients].

The contagiousness of hepatitis B virus (HBV) carriers with end-stage renal disease undergoing chronic hemodialysis has been ascribed to an immunologic tolerance for HBV antigens, especially hepatitis B core antigen, supporting persistently high levels of virus replication. In this context hepatitis B e antigen and core-associated DNA polymerase (DNA P) activity have proved to be distinct markers of HBV replication. In order to evaluate the potential infectivity of these subjects, thirty-five HBsAg positive hemodialysis patients were studied for the presence of HBeAg/anti-HBe system correlating the results with serum DNA P activity. Twenty out of 35 patients were HBeAg positive (57%) and 21 DNA P positive (60%). A highly significant correlation (P less than 0,001) was recorded between detection of HBeAg and presence of serum DNA P activity. These findings confirm that the majority of hemodialysis patients carrying HBsAg show high levels of virus replication so that the determination of HBeAg and DNA P activity other than HBsAg is required for the identification of patients highly infectious.

Chronic Disease↗

[Serologic diagnosis of acute hepatitis A. Refinement and evaluation of 3 methods of determining specific anti-HAV IgM].

A solid phase radioimmunoassay (RIA) procedure was developed and three methods for detection of IgM specific antibody to hepatitis A virus (anti-HAV IgM) were compared: triple antibody method, 2-MercaptoEthanol (2-ME) for IgM cleavage and Staphylococcal A Protein (StAP) for IgG absorption. Specificity and sensitivity of the tests were checked for evaluating acute and convalescent sera from 40 patients with serologically (seroconversion) diagnosed hepatitis A and 64 sera from patients with various acute viral diseases or with high titre of rheumatoid factor (RF). Specimens to be assayed for anti-HAV IgM were pretreated with 2-ME or StAP and tested by RIa using 125I labelled anti-HAV IgG. Triple antibody method showed to be more sensitive than other two methods giving false positive result in only one serum containing high levels of monoclonal RF. No significant difference in sensitivity and specificity was found between 2-ME and StAP procedure, but these methods were able to detect anti-HAV IgM for only two weeks after the onset of the disease, whereas triple antibody method gave positive results for at last seven weeks.

Antibodies, Viral↗

Genotyping of Streptococcus thermophilus evidenced by restriction analysis of ribosomal DNA.

Twenty strains of Streptococcus thermophilus were classified into five different types characterized by ribotyping after DNA digestion with HindIII and hybridization with cDNA from 16S-23S rDNA of Escherichia coli. Ribotyping after digestion with HaeIII and XhoI enabled the same strains to be gathered into three groups as a consequence of the reduced influence of the flanking sequences within the analysis of rRNA operons. Amplified rDNA restriction analysis clearly confirmed the discrimination of these three different ribotypes, producing evidence to suggest that subtaxa are to be recognized within this species.

Bacterial Typing Techniques↗

Genotyping of Lactobacillus delbrueckii subsp. bulgaricus and determination of the number and forms of rrn operons in L. delbrueckii and its subspecies.

Three different approaches (whole-cell protein profiles, DNA fingerprinting combined with pulsed-field gel electrophoresis and analysis of rDNA genes) were used to characterize thirty-one strains of Lactobacillus delbrueckii subsp. bulgaricus from different dairy products, and three type strains belonging to L. delbrueckii subsp. delbrueckii, L. delbrueckii subsp. lactis and L. delbrueckii subsp. bulgaricus. Moreover, the number and different forms of rrn operons in L. delbrueckii and its subspecies were defined. At the strain typing level, Notl macrorestriction analysis permitted grouping of the 32 strains of L. delbrueckii subsp. bulgaricus into 23 restriction patterns, providing a high degree of discriminatory power. Among whole-cell protein profiles, PCR analysis of rDNA genes and ribotyping, the latter method seemed to be the most reliable approach to characterizing the subspecies belonging to L. delbrueckii. Ribotyping combined with enzymes such as HindIII and EcoRI showed that at least six rrn operons were present in L. delbrueckii and its subspecies; two forms of rrn operons were present in the subspecies lactis and bulgaricus and four forms were present in the subspecies delbrueckii.

Blotting, Southern↗

White cell apoptosis in packed red cells.

BACKGROUND: After the removal of the buffy coat, packed red cell (RBC) transfusion units still contain white cells that may undergo apoptosis as a result of storage conditions (1-6 degrees C). The aim of the present study was the evaluation of this phenomenon in view of the possible influence it may have on febrile nonhemolytic transfusion reactions. STUDY DESIGN AND METHODS: Three independent methods (microscopy, DNA electrophoresis, and cytometry) were used to evaluate apoptosis in white cells present in 13 RBC units. Of these units, 10 had been collected into CPD/saline-adenine-glucose-mannitol and 3 into CPDA-1; each bag was split in two parts, one of which was irradiated. RBCs were stored at 1 to 6 degrees C, and samples were periodically withdrawn for study. The proliferative capacity of stored lymphocytes was evaluated after phytohemagglutinin stimulation and tritiated thymidine incorporation. RESULTS: Apoptosis was found to occur in both granulocytes and lymphocytes, starting from the first 48 to 72 hours of storage. The choice of the anticoagulant-preservative solution and the effect of irradiation did not influence the amount and the timing of the apoptotic phenomenon. Lymphocyte proliferative capacity was found to decrease sharply with storage time. CONCLUSION: Conditions of storage in RBCs induce consistent apoptosis in residual white cells. The possible clinical implications of the relationships between apoptosis and the induction of biologic response modifiers (that may cause interleukin-mediated febrile non-hemolytic transfusion reactions) and between apoptosis and immune reactions remain to be elucidated.

Adenine↗

Renal handling of sodium after an oral protein load in adult humans.

This investigation was designed to study (1) renal sodium handling after an oral protein load and (2) its relationship to some known determinants of the hemodynamic response (glucagon, insulin, growth hormone, renin, aldosterone, and plasma amino acid concentration). To this end of group of 8 adult subjects was studied before (three 30-min clearances) and after a meat meal (MM; five 30-min clearances at 30, 60, 90, 120 and 180 min). The MM provided 2 g/kg BW of protein. Within 30 min from the MM an hyperfiltration response was seen, which was paralleled by a 2-fold increase in plasma alanine concentration while total plasma amino acid concentration was not different from the baseline values. The hemodynamic response was associated with a normally operating tubuloglomerular feedback mechanism independent of renin-aldosterone activity, but possibly associated with an early increase in plasma glucagon concentration and later on with a modest increase in postmeal plasma insuling concentration.

Adult↗