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Biomedical subjects

G Cappelli

Publications and source records attributed to G Cappelli.

At least 37 records · Page 2Linked to original sources
PubMed1998

Maternal serum screening for trisomy 18 in the first trimester of pregnancy.

The aim of this study was to evaluate the feasibility of first-trimester biochemical screening for trisomy 18, by using pregnancy-associated plasma protein A (PAPP-A) and free beta human chorionic gonadotropin (hCG) in combination with maternal age. Maternal serum levels of PAPP-A and free beta-hCG were assayed retrospectively in stored sera from 323 singleton pregnancies at 8-13 weeks' gestation. These samples included 23 trisomy 18 pregnancies and 300 unaffected controls, diagnosed either at chorionic villus sampling or at mid-trimester amniocentesis. The median MOM in affected pregnancies was 0.25 for PAPP-A and 0.34 for free beta-hCG. Statistically significant reductions were found in the mean levels of both PAPP-A (t test: P < 0.000001) and free beta-hCG (p < 0.000001) in trisomy 18 affected pregnancies when compared with the unaffected samples. Screening for trisomy 18 using a combination of maternal age, PAPP-A and free beta-hCG would achieve a detection rate of 76.6 per cent for a false-positive rate of 0.5 per cent. These results suggest that first-trimester biochemical screening for trisomy 18 might be possible. Further investigations in a general population are needed before introducing such screening into clinical practice.

Chorionic Gonadotropin, beta Subunit, Human↗
PubMed1998

Erythropoietin upregulates the expression of its own receptor in TF-1 cell line.

In the erythroleukemia cell line TF-1, recombinant human erythropoietin (rHEpo), but not c-kit ligand, enhanced the number of cells expressing the erythropoietin receptor (EpoR), as measured by flow-cytometric analysis of binding of the biotin-labeled Epo. Moreover, 125I-Epo binding and Scatchard analyses, indicated that TF-1 cells, maintained in standard conditions with IL-3, and those stimulated with c-kit ligand, bear a single class of EpoR. On the other hand, cells cultured in the presence of rHEpo had a higher number of receptors than IL-3 or c-kit ligand-stimulated cells, and had two binding sites with different affinities for the ligand. EpoR mRNA expression was higher in cells exposed to rHEpo than in IL-3 or c-kit-stimulated cells. This difference may have been dependent on either a higher level of transcription or an increased stability of mRNA. The observed changes of EpoR in rHEpo-stimulated TF-1 cell line could cooperate, together with the alteration of the gene (3' end deletion), in the occurrence of the erythroleukemic process. Changes induced in EpoR by rHEpo were not accompanied by an increase in the expression of glycophorin A or globin chain mRNAs. This may suggest that rHEpo is unable to induce erythroid differentiation in TF-1 cells. The results also indicate that this cell line could be a model for the investigation of the role of transcription factor(s) in the expression of EpoR, and for the study of the mechanism(s) underlying the changes in the number and affinity of the cell receptors.

Erythropoietin↗
PubMed1998

Water quality for on-line haemodiafiltration.

The term 'ultrapure water' is a common way to define water used for on-line treatments: it refers to the absence of chemical, organic and microbiological contamination. To be more accurate in definition, every known and potential contaminant has to be fixed at its limit value. AAMI recommendations and various Pharmacopoeias have set limits for dialysate based on traditional dialysis treatments, but on-line treatments should also be regulated by guidelines for infusion solutions. Modern water treatment technology allows us to obtain a proper chemical quality both for dialysate and infusion solutions in on-line dialysis. Technology alone, however, cannot guarantee adequate microbiological quality if water treatment is not linked to the appropriate maintenance, monitoring, cleaning and sanitizing procedures. On-line dialysis treatments, as well as high-flux dialysis, use the monitor as an on-site pharmaceutical factory where sterilization by filtration forces nephrologists to look for procedures to keep sterile water sterile.

Hemodiafiltration↗
PubMed1998

Which level of cytokine production is critical in haemodialysis?

Monocyte activation with cytokine production is a well known event in the course of dialysis treatment but its relation to symptoms of haemodialysis or long-term pathological changes in chronic dialysis patients is still under discussion. Cytokine production depends on the balance between inducers and inhibitors while effects rely on the peculiar uraemic environment and cell metabolism. 'Foot-prints' for monocyte activation have been found, but no marker for clinical symptoms has been demonstrated clearly. In this scenario it is almost impossible to link a specific symptom to a definite stimulus such as dialysate microbial contamination or membrane complement generation. The topics discussed in this paper include cytokines synthesis modulation factors, levels in haemodialysis patients, and results of finding markers of clinical relevance. Special attention is paid to microbial contamination of dialysis fluid with analysis of cytokine inducing substances in commercial sterile solutions. Data on cytokine synthesis and activity in the aged are also discussed, with special regard to the haemodialysis setting.

Aged↗
PubMed1998

Vascular access for haemodialysis: from surgical procedure to an integrated therapeutic approach.

During the past 10 years the type of vascular access for haemodialysis procedures have changed markedly in our centre: more elbow AV fistulae and more central venous catheters are now used. Nevertheless, early referral to nephrologists and availability of central venous catheters and peritoneal dialysis allow elderly people to be admitted for dialysis treatment. Since vascular access for haemodialysis plays a key role in patient well-being, it is mandatory to apply quality assurance criteria to vascular access for haemodialysis surgery. Based on the results of a national survey, in Italy this policy is still in its early stages: monitoring of vascular access differs amongst centres, interventional radiology is used in a differing way, planning of vascular access for haemodialysis in pre-dialysis patients often remains an unsolved problem. According to our initial experience, we propose the use and validation of a quality-index [(minimum success rate) in elective vascular access for haemodialysis surgery], allowing accreditation of a department and a single surgeon for access management. Prevalence of central venous catheters at first dialysis of chronic renal failure patients is also proposed to evaluate the efficiency in access planning. Better knowledge of vascular access management by different teams could eventually lead to definition of guidelines for this 'Cinderella of dialysis'.

Arteriovenous Shunt, Surgical↗
PubMed1997

Mycobacterium tuberculosis enhances iNOS mRNA expression and HIV replication in human astrocytoma cells.

The aim of this study was to investigate whether Mycobacterium tuberculosis (MTB) infection affects human immunodeficiency virus (HIV) replication in T67 human astrocytoma cells and whether HIV and MTB infections induce iNOS mRNA expression in T67 cells. T67 cells were susceptible to both HIVLai and MTB infections, and MTB was able to increase HIV infection in T67 cells, as demonstrated by a marked increase in p24 release. Furthermore, both HIV and MTB infections strongly induced inducible nitric oxide synthase (iNOS) mRNA expression, as verified by RT-PCR. These findings suggest that HIV and MTB-induced iNOS expression of astroglial cells may be involved in the neuronal damage associated with HIV infection, particularly in the presence of opportunistic infections such as tuberculosis.

Astrocytoma↗
PubMed1996

No direct evidence of increased lipid peroxidation in hemodialysis patients.

Lipid peroxidation, as measured by the thiobarbituric acid test, has been reported to have increased in hemodialysis (HD) patients, even though the test has low specificity in vivo. Conjugated diene fatty acid (CDFA) hydroperoxides are formed during lipid peroxidation, but not all conjugated dienes (CD) detected in humans originate from lipid peroxidation: octadeca-9,11-dienoic acid, a nonhydroperoxide CD derivative of linoleic acid (CDLA), has a dietary origin. We evaluated CDFA hydroperoxides, CDLA and linoleic acid, using high-performance liquid chromatography, in lipids extracted from plasma, adipose tissue and RBC membranes obtained from 25 patients treated with HD, 16 patients treated with hemodiafiltration (HDF) and 29 controls. No differences in the levels of CDFA hydroperoxides and linoleic acid were seen in any of the groups. Concentrations of CDLA were found to be significantly high in the adipose tissue and low in the RBC membranes of HD patients. HDF-treated patients showed the same results as HD patients. No direct evidence of increased lipid peroxidation was found in HD patients. This does not exclude the possibility that lipid peroxidation is increased and escapes direct detection due to the body's homeostatic control eliminating the increased production of hydroperoxides. Both HD- and HDF-treated patients showed a significant change in CDLA concentrations, either in the adipose tissue, or in the RBC membranes. These dietary CD may be mistaken for markers of lipid peroxidation by conventional methodologies.

Adipose Tissue↗
PubMed1995

Tumor markers in breast cancer follow-up: a potentially useful parameter still awaiting definitive assessment. Forza Operativa Nazionale sul Carcinoma Mammario (FONCaM).

BACKGROUND: Although tumor markers are frequently used in the follow-up of patients with breast cancer, two points are still being debated: 1) their cost/effectiveness has been neither demonstrated nor disproved; 2) the reliability of the currently used dichotomous division into a positive/negative cut-off should be definitely validated. Dynamic criteria of interpretation based on serial serum samples would probably be more effective for early detection of relapse. PATIENTS AND METHODS: The aim of the present study was to compare the dichotomous cut-off based decision criteria to a dynamic serial sample based assessment of tumor markers. Since 1989, 794 patients have been followed in 11 institutions. CEA and CA15.3 were measured once a month for three months before every clinical examination. The present paper concerns the evaluation variability in 405 patients without evidence of disease in the first three institutions joining the study. RESULTS: In patients without evidence of disease, the coefficient of variation of all samples for every patient showed a median value of 19 for CEA and 21 for CA15.3. Variability was negatively associated with the antigen level and was most likely due to the analytical component. This was also confirmed by the significant difference in variability among the three institutions evaluated. The median value of the critical difference was 53% for CEA and 57% for CA15.3. CONCLUSIONS: 1) Individually tailored dynamic decision criteria are applicable in about 50% of the cases. 2) The problem of improving the precision of tumor marker assays in the low dose range must be urgently addressed to the manufacturers of tumor markers by the scientific community in order to apply individually tailored decision criteria for patients in whom the serum level of biological markers is low.

Biomarkers, Tumor↗
PubMed1995

Serum eosinophil cationic protein (ECP) in bullous pemphigoid.

BACKGROUND: The importance of eosinophils in the pathogenesis of the major forms of pemphigoid (bullous pemphigoid, cicatricial pemphigoid, herpes gestationis) remains to be confirmed. METHODS: To evaluate the role of eosinophilic infiltrates in these diseases and to detect the presence and activity of eosinophils, we compared the serum levels of eosinophil cationic protein (ECP), an eosinophil-derived protein, in 11 healthy subjects and in 10 patients with pemphigoid diseases (8 with bullous pemphigoid, one with cicatricial pemphigoid, and one with herpes gestationis). The serum of two patients with epidermolysis bullosa acquisita (EBA) and one with linear IgA bullous dermatosis (LABD) were utilized as a further control. RESULTS: There was a significant difference between the mean of serum ECP levels in patients with pemphigoid diseases (25.1 +/- 12.3 micrograms/L, M = SD) and control subjects (2.30 +/- 2.41, micrograms/L +/- SD 2.41) (T = 4.272 P < 0.0001). The two patients with EBA (10.8 and 17.7 micrograms/L) showed contrasting results; the patient with LABD had normal ECP serum levels. The serum levels of ECP were not significantly correlated with the blood eosinophil count (R = 0.103; P = 0.777) in any of the cases. CONCLUSIONS: In pemphigoid disease, the serum levels of ECP seem to be correlated with the activated secreting and tissue-damaging eosinophils found in the dermis, supporting the concept of an active participation of eosinophils in generating cutaneous lesions.

Adult↗
PubMed1995

Leaching and corrosion of polyvinyl chloride (PVC) tubes in a dialysis water distribution system.

PVC tubes, from the dialysis water distribution system of a 14 and a 7 year old plant, were analysed by scanner electron microscopy (SEM) and X-ray microanalysis (EDAX). Results showed that the leaching of material occurs depending on time of use. The phenomenon does not modify the chemical composition of the material. Results suggest that PVC alterations, induced by time, could support bacterial proliferation thus reducing the quality of dialysate.

Corrosion↗
PubMed1995

Amniotic fluid levels of CA 19.9 and CA 15.3 in normal and Down's syndrome pregnancies.

CA 125, CA 19.9 and CA 15.3 are antigenic determinants on glycoproteins commonly used as serum markers in gynecologic oncology. CA 125 was also investigated in the amniotic compartment of Down's syndrome pregnancies. The objective of this study was to evaluate the concentration of CA 19.9 and CA 15.3 in the amniotic fluid of normal and Down pregnancies. The concentration of these antigens was measured in stored amniotic fluid samples from 15-19 weeks pregnancies with and without Down's syndrome fetuses and expressed in multiples of the median for normal pregnancies of the same gestational age. The study group included 20 samples selected from single Down's syndrome pregnancies. Each of these samples were matched with three control samples from unaffected pregnancies, matched for maternal age, gestational age and duration of storage of the sample. The median MoM values of CA 19.9 and CA 15.3 in Down's syndrome pregnancies were respectively 1.11 MoM and 1.16 MoM, not significantly different from those of unaffected pregnancies (CA 19.9: 1.02 MoM; CA 15.3: 0.99 MoM). In the present study we have not found significantly different levels of CA 19.9 and CA 15.3 in the amniotic fluid of fetuses affected by Down's syndrome and in the controls.

Amniotic Fluid↗
PubMed1995

How alternative are immunoassay systems employing non-radioisotopic labels? A comparative appraisal of their main analytical characteristics.

The immunoassay is one of the most sensitive and reliable analytical techniques available in the clinical laboratory. The original label for immunoassays was radioisotopes, and these methods, radioimmunoassay (RIA) and immunoradiometric assay (IRMA) are still the reference methods, because of invulnerability of the radioactive emission with respect to environmental interference. Labels other than radioisotopes have been tested for use in immunoassay to improve the sensitivity and reliability and to avoid some of the disadvantages of radioisotopic techniques. New labels have continued to be developed (Horseradish peroxidase-HPR-, pyrophosphatase, luciferases, pyrodopirazines, europium cryptates, porphirins, phosphors) and new label detection methods have been set up (e.g. chemiluminescence assay, thermometric assay, NADP+ and FADP- based coupled assay). New immunoassay strategies such as simultaneous multianalyte automated test have been developed and the reliability of the assays has in some cases caused division among researchers about the choice between the radioisotopic immunoassay or the non-radioisotopic immunoassay, as considerable effort and investment had been devoted to the search for more sensitive and practicable tests than the classic RIA-IRMA methods. The evolution of immunoassays (Monoclonal Antibodies, non-radioactive tracers, automation) has produced systems which allow a large number of laboratories to determine a great number of analytes with very good practicability. The availability of fully automated systems has generated the opinion that analytical performance of immunoassays can be considered similar to that of many traditional parameters of clinical chemistry. This conclusion seems however too optimistic, in fact data collected from interlaboratory studies demonstrate that problems concerning the analytical reliability of the measurements still remain not completely solved. In the authors' opinion, this opposition between immunological assay based on isotopic or non-isotopic labels is misleading, because each assay (whether it uses isotopic, enzymatic, fluorimetric or luminescent labels) has its own analytical characteristics and performance. For this reason the term "alternative", used to indicate all non-isotopic assays as a unique class of tests, should be abandoned. From a theoretical point of view the choice should not be between isotopic and non isotopic techniques. For each analyte to be tested, it is advisable to use the immunological assay that suits the requirements of the laboratory, irrespective of type of label. From a practical point of view, the choice should be based on the analytical performance and on the characteristics of each assay, on its cost and the type of instrumentation available in the laboratory, and on the experience and the knowledge of the laboratory personnel.

Costs and Cost Analysis↗
PubMed1994

Selective expansion of cytotoxic T lymphocytes with a CD4+CD56+ surface phenotype and a T helper type 1 profile of cytokine secretion in the liver of patients chronically infected with Hepatitis B virus.

Highly purified CD4+ T cells isolated from liver biopsies of patients with hepatitis B virus-induced CAH had a strong cytotoxic activity and were comprised of a substantial number of cells (25%-40%) expressing CD56 surface marker. These cells were absent in CD4+ T cells from the peripheral blood of CAH patients or normal controls and these suspensions did not have cytotoxic activity. CD4+CD56+ T cells were further characterized by studies at the clonal level. A total of 71 hepatitis B envelope antigen-specific CD4+ T cell clones was investigated (23 from liver biopsies, 48 from peripheral blood of patients or normal vaccinated individuals). A total of 16 out of 23 (69.5%) of the clones from liver biopsies, but only 4.1% (2 out of 48) of those from PBLs, expressed CD56. A clone was defined as CD56+ when 40% or more of the cells expressed the marker. Production of TNF-alpha, IL-4, IL-5, IL-2, and IFN-gamma was investigated in 15 CD4+CD56+ and in 18 CD4+CD56- T cell clones, which shared the same HLA restriction element (DR2w15) and the same fine specificity (peptide 193-207 of the S region). All of the clones from the two groups released TNF-alpha and IL-2. However, all of the CD4+CD56+ T cell clones produced IFN-gamma but not IL-4 and IL-5 (Th1-like cell clones). Fourteen of the CD4+CD56- clones released IFN-gamma, IL-4, and IL-5 (Th0-like cell clones); three produced IL-4 and IL-5 but not IFN-gamma (Th2-like cell clones); and only one had a Th1 cytokine secretion profile. Cell fractionating studies within single CD4+CD56+ T cell clones showed that cells expressing high density CD56 had a stronger cytotoxic activity and produced higher levels of IFN-gamma than cells with low density CD56, thus further supporting a correlation between CD56 expression and cell functions. The results indicate that: 1) in CAH patients, cytotoxic CD4+ T cells with a Th1 cytokine secretion profile are compartmentalized in the liver, 2) these cells may be identified by the expression of CD56, 3) the expansion of these cells may be facilitated by antigenic stimulation within the inflammatory environment of the liver, and 4) CD4+CD56+ cells may play a pathogenetic role in hepatitis B virus infection.

Adult↗
PubMed1994

Mathematical model application to the kinetic study of tumor markers.

In order to overcome the inefficient cutoff criterion in the management of neoplastic patients after therapy, in follow-up, in recurrence and in monitoring treatment, we have analysed some mathematical models to evaluate serial determinations of tumor markers, with the aim to ascertain the radicality of surgery or the presence of recurrences. Since a tracer study of the biological system of tumor markers is impossible, some information, such as rate factor and half-life, is obtained by determination of the marker after radical treatment. In steady state with two or more samples in time it is possible with adequate statistical models to establish a significant increase in the marker. In recurrence, if it is true that the secretion rate of the marker by a tumor is proportional to tumor mass, then increasing concentrations of the tumor marker would be a phenotypic expression of tumor growth. Therefore some mathematical models are proposed to evaluate the kinetics of tumor growth.

Biomarkers, Tumor↗
PubMed1994

On line filtration of dialysate: structural and functional features of an asymmetric polysulfone hollow fiber ultrafilter (Diaclean).

The endotoxin transfer across dialysis membranes has been investigated using specific in vitro circuits. Backdiffusion and backfiltration have been analyzed and most dialysis membranes have shown to be permeable to LAL positive substances. Synthetic membranes however display the better capacity of retention of these products despite their higher porosity and permeability. For such reason synthetic polysulfone ultrafilters are used as pyrogen filters to obtain ultrapure dialysate. We have investigated the characteristics of a polysulfone ultrafilter named Diaclean and manufactured by Amicon Ireland. The capacity of endotoxin retention has been investigated both in filtration and backfiltration modes on new and used ultrafilters. The capacity of endotoxin adsorption was investigated as well. Used ultrafilters appeared to maintain the retention capacity and the adsorption capacity up to 4 months of use. Only slight differences were noted from the baseline values (p = n.s.). The best adsorption capacity is always displayed by the outer layer of the membrane suggesting its best utilization in back filtration mode with tangential flow. No morphological changes were observed in the used membrane analyzed by scanning electron microscopy.

Diffusion↗
PubMed1993

Effects of low-dose captopril on renal hemodynamics and function in patients with cirrhosis of the liver.

BACKGROUND: In cirrhotic patients with ascites, captopril has deleterious effects on renal function, which have been referred to as captopril-induced arterial hypotension. The effects of this drug on renal function in cirrhosis were evaluated using low-dose captopril, thereby avoiding any change in arterial pressure. METHODS: In a randomized, double-blind, placebo controlled, cross-over trial, the effects of 12.5 mg captopril on renal plasma flow, glomerular filtration rate (measured by radioisotopic techniques), and sodium excretion in healthy controls and cirrhotic patients with and without ascites were determined. RESULTS: In healthy subjects, captopril only induced a significant, 18% increase in renal plasma flow. In contrast, glomerular filtration rate significantly decreased in patients with (from 108 +/- 7 to 78 +/- 9 mL/min) and without ascites (from 102 +/- 4 to 88 +/- 3 mL/min), whereas renal plasma flow did not change. Urinary sodium excretion also significantly decreased in ascitic patients (from 43.8 +/- 4.4 to 30.6 +/- 3.8 mumol/min). CONCLUSIONS: These data suggest that angiotensin II contributes to maintain renal hemodynamics in cirrhosis with and without ascites.

Aged↗
PubMed1993

Conjugated diene fatty acids in patients with chronic renal failure: evidence of increased lipid peroxidation?

Conjugated diene fatty acids (CDFA) were evaluated by second derivative spectrophotometry in the plasma and adipose tissue of 42 chronic renal failure (CFR) patients in conservative treatment, 40 patients treated by hemodialysis (HD) with cuprophane, cellulose acetate or hemophan, 29 treated by hemodiafiltration (HDF) with polysulfone, polyacrylonitrile or polyamide, and 28 healthy controls. Plasma CDFA were also evaluated at the beginning, at 30 min and at the end of the dialytic session. CDFA were unchanged in CRF patients with creatinine clearance (Ccr) > 10 ml/min respect to the controls, CRF patients with Ccr < 10 ml/min showed a higher level of CDFA both in plasma and adipose tissue (p < 0.02). HD patients showed values similar to those of the control group. The lowest level of CDFA was found in HDF patients (p < 0.01 for plasma, p < 0.05 for adipose tissue versus both control and any other group). A significant relationship between plasma and adipose tissue CDFA was found in all groups. In the group of CRF patients with Ccr < 10 ml/min, females exhibited a higher level of CDFA both in plasma and adipose tissue. No significant change was found during dialytic session, independently from the membrane used. CDFA are not only primary products of lipid peroxidation, but also have a dietary origin, primarily from dairy products. Taking into account the reduced dietary intake, the increase in end-stage CRF may be due to an enhanced oxidative stress and/or to abnormalities in CDFA metabolism. Uremic patients, particularly in the predialytic stage, should be considered at risk for increased oxidative stress. HDF treatment better corrects the abnormality compared to conventional HD.

Adipose Tissue↗