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D Villalta

Publications and source records attributed to D Villalta.

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

Variability between methods to determine ANA, anti-dsDNA and anti-ENA autoantibodies: a collaborative study with the biomedical industry.

This study was performed by the Italian Society of Laboratory Medicine (SIMeL) in order to establish the variability between the different analytical systems currently used in clinical laboratories for the detection of autoantibodies diagnostic of systemic autoimmune disease. Sixteen industrial, and two university laboratories participated in this study which entailed the determination of anti-nuclear (ANA), anti-dsDNA and anti-ENA antibodies in 11 sera from patients with clinically diagnosed systemic rheumatic disease, using reagents produced by these companies and different methodologies (indirect immunofluorescence, immunoenzymatic assay, counterimmunolectrophoresis, immuno and western blotting). We found 93.5% agreement between the methods used for the detection of ANA, 85.2% for anti-dsDNA antibodies, and 86.9% for anti-ENA antibodies. Among the anti-ENA antibodies, regardless of the method used, detection percentages were excellent for anti-RNP and anti-SSB/La (100%), good for anti-SSA/Ro (93%), but unacceptable for the anti-Jo-1 (67%), anti-Scl70 and anti-Sm (47%) antibodies. This further stresses the need for rigorous standardisation of commercial reagents and analytical procedures, as well as the introduction of external quality assessment (EQA) programs, and a complete definition of operative protocols adjusted to the sensitivity and specificity of the various methods.

Antibodies, Antinuclear↗
PubMed1992

Relief of pruritus and decreases in plasma histamine concentrations during erythropoietin therapy in patients with uremia.

BACKGROUND: The pathophysiologic aspects of pruritus in patients with chronic renal insufficiency are poorly understood, and there is no universally effective treatment. The improvement of pruritus in several patients receiving erythropoietin therapy raised the possibility that erythropoietin affects uremic pruritus directly. METHODS: We undertook a 10-week placebo-controlled, double-blind, crossover study in a group of patients receiving hemodialysis who had severe pruritus, to investigate the effects of recombinant human erythropoietin on their pruritus and plasma histamine levels. Twenty patients with uremia, of whom 10 had severe pruritus and 10 did not, received erythropoietin (36 units per kilogram of body weight three times weekly) and placebo in random order, each for five weeks. The severity of pruritus was scored weekly, and plasma histamine levels were measured at the beginning and end of each five-week period. RESULTS: Eight of the 10 patients with pruritus had marked reductions in their pruritus scores during erythropoietin therapy. The mean (+/- SE) pruritus score decreased from 25 +/- 3 to 6 +/- 1 in these patients. The pruritus returned within one week after the discontinuation of therapy. The improvement was not related to the change in hemoglobin level. These eight patients were successfully treated again with low doses of erythropoietin (18 units per kilogram three times weekly), and the effect has persisted for six months. The patients with pruritus had elevated plasma histamine concentrations (20.7 +/- 2.7 nmol per liter), as compared with the patients without pruritus (4.2 +/- 0.6 nmol per liter; P less than 0.001) and normal subjects (2.1 +/- 0.2 nmol per liter; P less than 0.001). Therapy with erythropoietin induced a decrease in plasma histamine concentrations in both groups of patients with uremia, and recurrences of pruritus after the discontinuation of erythropoietin were accompanied by increases in plasma histamine concentrations. CONCLUSIONS: Erythropoietin therapy lowers plasma histamine concentrations in patients with uremia and can result in marked improvement of pruritus.

Double-Blind Method↗
PubMed1991

Evaluation of an automated commercial immunoluminometric assay for alpha-foetoprotein.

We evaluated a two-site immunoluminometric assay (AFP LIA-mat Byk Sangtec) for the determination of alpha-foetoprotein (AFP). The assay, involving two monoclonal antibodies which recognize two different alpha-foetoprotein epitopes, is rapid (4 h) with a wide working range (0-600 x 10(3) IU/l), a good lower limit of detection and good reproducibility (CV less than 10%). The regression equation for the AFP LIA-mat (y) and the immunoradiometric assay AFP Bridge Serono (x) was y = 1.175x - 2.27 (n = 95, r = 0.996) for serum and y = 1.16x + 479.2 for amniotic fluid. It did not display a hook effect, and when we assessed the linearity by assaying a high concentration of alpha-foetoprotein, it gave a linear response down to 3.1 x 10(3) IU/l. We also evaluated the clinical response of AFP LIA-mat in 278 patients with different diseases. Eighteen of the 19 patients with hepatocellular carcinoma had alpha-foetoprotein levels greater than 100 x 10(3) IU/l. In contrast, only 5 of the 47 patients with cirrhosis showed values above 50 x 10(3) IU/l, demonstrating that this assay discriminates fairly well between hepatocellular carcinoma and cirrhosis. Data in agreement with the literature were obtained for testicular tumours; all of seven seminomatous tumours presented values below 5 x 10(3) IU/l, whereas 50% of the non-seminomatous tumours (n = 8) presented values above 20 x 10(3) IU/l.

Autoanalysis↗
PubMed1989

Time-related shape control modifications during erythrocyte storage with additive solutions.

To obtain more detailed information on the reversibility of shape alterations in blood bank stored erythrocytes, we have studied shape recovery after chemical crenation and rheological properties in 8 PAGGS-sorbitol preserved erythrocyte concentrates during a five week storage period under blood bank conditions. Our results show that red cell capability to regain a normal discoid shape after chemical crenation decreases during storage but is not lost over a five week period. Moreover there is a significant but weak correlation between red cell ATP content and both shape recovery capability and viscosity. Our results confirm suspicious that red cell shape perturbations following blood bank storage are widely reversible. Two different mechanisms may be involved in reducing shape recovery capability during storage, namely an ATP-dependent mechanism and an energy-independent one. The energy dependent mechanism may be preserved by the previous addition of solutions which maintain higher energy levels during storage.

Adenine↗
PubMed1989

Critical evaluation of bioluminescence methods for quantifying bacterial adhesion to polystyrene.

A total of 134 strains of Escherichia coli which included 60 fecal and 74 urinary isolates, cultured in liquid and on solid media, were examined for adhesive properties using bioluminescence and haemagglutination methods. The study aimed to verify whether irrespective of the absence or presence of flagella, there is any relation between haemagglutination and bioluminescence test. Examining the results we failed to note any correlation between the two methods: strains bearing MS, MR or MS-MR adhesins adhered to polystyrene at random. Even though it is fast and easy to perform, bioluminescence is not an alternative to traditional methods to reveal MS adhesins.

Adhesins, Escherichia coli↗
PubMed1987

A method for the determination of the adherence of granulocytes to microtitre plates.

We report a new partially automated method for the measurement of the adherence of PMN in vitro. Adherence to a plastic surface was detected by measuring leukocyte alkaline phosphatase activity of the adherent cells, with a Titertek Multiscan system. Using three different cellular concentrations (1 X 10(6), 5 X 10(5), 2.5 X 10(5) PMN/ml) the response curve was linear to 45 min and adhesion was maximal by 30 min. The specificity of the reaction was acceptable as was the assay reproducibility (intra-assay coefficient of variation less than 8%; inter-assay coefficient of variation less than 11%).

Alkaline Phosphatase↗
PubMed1987

Alternating tamoxifen and medroxyprogesterone acetate in postmenopausal advanced breast cancer patients--short and long term endocrine effects.

The endocrine effects of alternating tamoxifen and medroxyprogesterone acetate have been evaluated in 26 post-menopausal patients with metastatic breast cancer. Endocrine evaluations included the RIA determination of plasma levels of sex-hormone binding globulin, follicle-stimulating hormone, luteinizing hormone, estradiol, prolactin, cortisol, and testosterone. The evaluation of the study parameters at different intervals during therapy indicates that with this schedule an alternate sequential effect on the endocrine system is achievable because each drug exerts its own endocrine activity that is completely reversed when the other drug is administered. We can hypothesize that the same alternate activity as seen on the endocrine system could be obtained also on other tissues and organs including tumors.

Breast Neoplasms↗
PubMed1987

Sequential combination of tamoxifen and high dose medroxyprogesterone acetate: therapeutic and endocrine effects in postmenopausal advanced breast cancer patients.

A sequential combination of tamoxifen and medroxyprogesterone acetate has been evaluated in 42 postmenopausal untreated patients with metastatic breast cancer. Patients received tamoxifen 10 mg b.i.d., days 1-14, followed by medroxyprogesterone acetate 500 mg b.i.d., days 15-28, orally in an alternating sequence until progression. Twenty-two out of 40 evaluable patients showed an objective response to treatment (55%, 95% confidence limits 38-75%). A significantly higher response rate was observed in patients with age greater than or equal to 70 years, with soft tissue dominant lesions and with only one metastatic site. Median time to progression was 41 weeks and the median survival time 88 weeks. In 4 cases treatment was discontinued because of severe toxicity while in the remaining patients no toxicity (20 patients) or mild side effects (17 patients) have been observed. After 2 months of therapy, this combination showed a progestogenic effect on the endocrine parameters inducing a significant decrease of SHBG, gonadotropins, testosterone and cortisol. These preliminary clinical results and the moderate toxicity of the sequential combination support the need to further investigate this approach.

Adult↗
PubMed1987

Serum reverse T3 assay for predicting glucose intolerance in uremic patients on dialysis therapy.

Sixty patients with end stage chronic renal failure (CRF) enrolled in a dialysis program underwent studies of serum thyroid hormones and carbohydrate metabolic state. The aim of the study was: 1) to evaluate whether the glucose intolerance per se represents a factor for the alteration of circulating thyroid hormones; and 2) to explore the potential usefulness of specific thyroid hormones and particularly reverse T3 (RT3) as indicators for predicting glucose intolerance. Forty-two patients received hemodialysis and 18 were on intermittent peritoneal dialysis (IPD). CRF patients had reduced serum total T4 and T3 levels, slightly decreased RT3 and TBG concentrations and normal TSH values. There was no significant difference in serum thyroid hormone indices between HD and IPD patients. Glucose intolerance was found in 25 patients. Ten had fasting hyperglycemia and diabetic response to oral glucose tolerance test (OGTT), 15 had an impaired glucose tolerance according to the criteria of the National Diabetes Data Group. In CRF patients with glucose intolerance, serum T3 and T3/T4 molar ratio were significantly lower than in those with a normal OGTT response, whereas serum RT3 and RT3/T4 molar ratio were found to be higher. In the whole group of CRF patients these serum thyroid hormones closely correlated with glucose tolerance indices. To investigate the usefulness of serum RT3 assay in predicting glucose intolerance we compared the outcome of the OGTT and serum RT3 values. Using the results of the OGTT as the true diagnosis of glucose intolerance, serum RT3 assay showed a diagnostic specificity of 94.2% and a sensitivity of 100%. In conclusion these results suggest that: 1) the glucose intolerance, which frequently occurs in uremia, may influence circulating thyroid hormones probably leading to a shift in the peripheral tissue conversion of T4 from T3 to RT3; and 2) serum RT3 assay could assume a clinical interest in assessing carbohydrate metabolic state in treated end stage renal failure independently of the type of dialysis therapy.

Adult↗
PubMed1986

Familial hypercholesterolemia and HLA antigens.

Hereditary factors play an important role in the etiology and progression of coronary heart disease (CHD), most probably by causing the appearance and the levels of its risk factors. To investigate if there is a correlation between familial hypercholesterolemia and HLA system antigens, 25 subjects of 7 families with familial hypercholesterolemia were compared with 14 normocholesterolemic related subjects. Compared to normocholesterolemic kindreds, the familial hypercholesterolemic subjects have a significant increased HLA-Bw35 antigen and a lack of HLA-A1. Therefore, the correlation found with some HLA system phenotypes improves our knowledge about familial hypercholesterolemia and aids in the identification of subjects affected with this disorder of lipid metabolism, which is one of the most important CHD risk factors.

Adolescent↗
PubMed1986

Persistent generalized lymphadenopathy in Northeastern Italy: increased frequency of HLA-DR 5.

We undertake a study of Italian intravenous drug abusers and male homosexuals with the prolonged generalized lymphadenopathy syndrome (PGL). 75% of the subjects had the HLA-DR 5 antigen (relative risk 3.25). Only one patient was DR 2 positive. 14/20 subjects had anti-HTLV III antibodies and immunological malities were a rather constant finding.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Close genetic linkage between HLA and renal glycosuria.

Renal glycosuria is an inherited disorder of renal tubule function in which significant amounts of glucose are excreted in the urine in the simultaneous presence of normal blood glucose levels. Renal glucose titration analyses and HLA genotypes were performed in 5 unrelated affected families with a total of 25 patients and 40 healthy relatives. In each family the gene responsible for renal glycosuria segregates with the HLA complex suggesting a close genetic linkage. 2 cases carry intra-HLA recombinant haplotypes; in these subjects our findings indicate that the abnormal gene is closer to the HLA-A locus than the HLA-B locus. No HLA-A, HLA-B or HLA-C specific antigen is selectively increased among the 5 unrelated families affected with renal glycosuria.

Adolescent↗
PubMed1984

Immunological characterization of renal glycosuria patients.

We have evaluated the autoantibody pattern, the production of specific immunoglobulins against bacteria in the urinary tract and lymphocytes populations in peripheral blood of primary renal glycosuria patients. All the affected members present autoantibodies against various antigens. In nine patients immunofluorescence revealed antibody coated bacteria in urine specimens. Imbalances in lymphocytes subpopulations are also present, with a reduction of OKT8+ cells and an increase of B and natural killer cells. These results support previous observations about immunological abnormalities in these patients.

Adult↗
PubMed1983

Is renal glycosuria a benign condition?

HLA typing and a range of autoantibodies were evaluated in five families affected with type A renal glycosuria. HLA typing demonstrates that this inherited disease is controlled by an autosomal dominant gene located on chromosome six in close genetic linkage with the HLA complex. All affected family members have significant titres of autoantibodies to nuclear antigens, native DNA, smooth muscle, mitochondria, liver antigens, thyroglobulin, thyroid microsomes and renal tubule brush border with variable association. This suggests that renal glycosuria is a complex HLA-linked disease with increased susceptibility to multiple autoantibody production and this urges caution with respect to its classical definition as a benign condition.

Adolescent↗