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Biomedical subjects

G Ceriotti

Publications and source records attributed to G Ceriotti.

At least 19 recordsLinked to original sources

Polymorphism of bovine MHC class I genes. Joint report of the Fifth International Bovine Lymphocyte Antigen (BoLA) Workshop, Interlaken, Switzerland, 1 August 1992.

The objectives of the Fifth International BoLA Workshop were to: standardize nomenclature, compare typing methods, and characterize BoLA haplotypes. The workshop was based on the distribution of blood samples (cells) from 60 selected cattle to 14 laboratories. Results for the class I (BoLA-A) region are presented in this paper while results for the class II regions are presented in a separate report. Thirty-six of the 50 previously established serological class I specificities were represented in the cell panel. However, only 30 specificities could be confirmed. Two specificities, A16 and A32, were upgraded from provisional, workshop (w) specificities to BoLA-A locus specificities and three new specificities, w51(w28), w52 and w53(w28), were defined. The 39 specificities distinguished 30 class I haplotypes in the 60 animals. Class I isoelectric focusing proved to be a useful adjunct to the serology. Isoelectric focusing confirmed several serologically defined splits and detected splits of A15(A8), A18(A6) and A22(w49) that had not been detected by serology. Subsequently, serological support for splits of A15(A8) and A22(w49) was found.

Animals

Measurement of alkaline phosphatase activity in serum with N-methyl-D-glucamine as a buffer: evaluation of the method for routine use.

Some aspects of the measurement of alkaline phosphatase activity concentration in human serum, using N-methyl-D-glucamine as a buffer, were evaluated with a view to the possible routine use of the method. The evaluated characteristics included: the temperature-dependence of the pH of the buffer; the effect of adding the magnesium/zinc ions buffer; the effect of the serum volume fraction; the substrate-starter versus the serum-starter mode; the effect of modifying the formulation of reagents; the within-run and the between laboratory imprecision; the correlation with an alternative routine method. Also, sex- and age-related reference values were produced, based on 2968 values from selected reference sample groups in 7 laboratories. In general, the results demonstrate the robustness of the method, its adaptability to a variety of mechanized analysers, and hence its feasibility as a routine measurement method.

Adolescent

In vitro and in vivo behaviour of narciclasine released from matrices based on poly (2-hydroxyethyl methacrylate).

Narciclasine (1,2,3,7-tetrahydroxy-8,9-methylendioxy-1,2,3,4-tetrahydrophena ntridone) is a natural substance with strong antimitotic effects on cells and potential antitumor activity. Its release form a hydrogel matrix was studied with the purpose of avoiding the concentration spikes of the parenteral administration. The matrix prepared by gamma ray polymerization of a mixture of 2-hydroxyethyl methacrylate (85%) and trimethylolpropane trimethacrylate (15%) was found to release narciclasine for several days, according to a diffusion controlled mechanism. In agreement with its antimitotic effect, narciclasine inhibited the growth rate of healthy mice, when the drug-loaded matrix was introduced subcutaneously. Antitumor effect was observed in an experimental model of Erlich ascitic tumor when low amounts of tumor cells were inoculated. No effect was observed at high concentrations of inoculum or towards solid tumors (Sarcoma 180). This behaviour was related to the rapid clearance of narciclasine from the body which prevented the reaching of sufficient therapeutical concentrations. A pharmacokinetic investigation carried out by an original method of assay demonstrated that narciclasine was accumulated in significant amounts in the kidney only and eliminated in urine with a half time of less than 20 min.

Alkaloids

European Multicentre Evaluation of the ESAT 6660.

The analytical performance of the glucose analyser ESAT 6660 from Eppendorf was studied according to the ECCLS guidelines and partly according the SFBC protocol in a multicentre evaluation involving laboratories from three European countries. The glucose determination in serum and in haemolysate was studied. The following results were obtained. 1. The precision was as good as or better than the precision of the comparison instruments. The coefficients of variation were between 1.1 and 3.4% for the between-days imprecision and between 0.35 and 1.45% for the within-run imprecision experiment. 2. The recovery of control sera values compared with the hexokinase method was between 94.3 and 102.6%. 3. With patient specimens as good agreement was found between the results obtained with the ESAT 6660 and the different comparison instruments (ASTRA, Hitachi 737 and ACP 5040). 4. A drift effect of 1.1-2.3% occurred in 5 of 21 experiments, depending on the individual enzyme membrane. 5. Sample carry-over was not observed. 6. A linearity between 0.5 and 50 mmol/l was found, exceeding the manufacturer's claims. 7. Several different endogenous and exogenous interferences were investigated. No interfering effect was detected for endogenous substances. A positive interference was observed by ascorbic acid at a concentration above 350 mg/l. 8. The practicability of the instrument was judged as very good. It was considered as a disadvantage that the instrument is not capable of piercing sample lids. Also the numeration of samples is not very convenient.

Blood Chemical Analysis

Lipid bound sialic acid in cancer patients.

Serum lipid-bound sialic acid (LSA) was measured with a recently described procedure in 108 healthy subjects and in 138 patients with a variety of solid tumors and hematologic malignancies. At the time of serum sampling, 128 patients had active disease and 10 patients had no evidence of disease. LSA was elevated in 104 of 128 (81.2%) patients with active disease, while carcinoembryonic antigen, analyzed in 74, was elevated only in 21 (28.4%) (P less than 0.05). Sensitivity of the serum LSA test ranged from 66% for breast and gastrointestinal cancer to 92% for lung cancer. In patients with lung cancer, ovarian cancer or Hodgkin's disease, LSA was correlated with the extent of disease and it also proved to be useful in following the course of disease. Our preliminary data indicate that this test can be used as a monitor of tumor burden.

Breast Neoplasms

Multi-centre evaluation of the urine test strip analyser Rapimat.

A multi-centre evaluation of the test strip analyser, Rapimat, was performed by four laboratories following the ECCLS 2nd draft guidelines for the evaluation of analysers in clinical chemistry. Using the Rapignost urine test strip with the test fields for bilirubin, urobilinogen, acetoacetate, ascorbic acid, glucose, protein, nitrite, pH and haemoglobin, the Rapimat was found to be analytically reliable in comparison with other, in most cases quantitative procedures. During the observation period of about 6 months no breakdown occurred in any laboratory. Interferences and sensitivity as discussed for the bilirubin and urobilinogen test field are more related to the test strip than to the instrument. Several improvements for further developments are suggested. This multi-centre study has shown that the ECCLS protocol is applicable to analytical procedures leading to discrete results.

Chemistry, Clinical

Pepsinogen Group I radioimmunoassay and total serum pepsinogen colorimetric determination: a comparative study in normal subjects and in peptic ulcer patients.

Pepsinogens, proteolytic enzymes produced by peptic cells of the stomach and discharged into the gastric lumen as well as into the blood have been divided into two groups: PG-I, originating from chief cells, and PG-II, mainly from antrum peptic cells. Both total serum pepsinogen (s-Pg) and PG-I have been separately reported as being significantly increased in gastric (GU) and duodenal ulcer (DU) patients and related to maximal acid output. In order to ascertain the relationship between s-Pg measured by means of the colorimetric Uete method, and PG-I determined by RIA method, these were assayed in 72 control subjects, 35 GU and 95 DU patients. s-Pg was found to be significantly increased both in GU and DU patients in comparison with control subjects. Likewise PG-I was significantly enhanced in GU and DU patients as compared with controls. A significant direct correlation between s-Pg and PG-I was found in all the subjects studied (r = 0.732).

Adult

Kinetic enzymatic determination of creatinine by a rapid semiautomated procedure.

The enzymatic method of creatinine determination, based on the transformation of creatinine to creatine by creatinine amido-hydrolase (EC 3.5.2.10) and subsequent evaluation of the creatinine, has been automated as a kinetic initial rate procedure. This was achieved by using a preincubation period under conditions that reduce the interference by accessory reactions to a very low and constant value, followed by a relatively high concentration of creatinine amido-hydrolase as a starter.

Creatine Kinase

Role of trypsin/creatinine clearance ratio in the differential diagnosis of chronic pancreatic disease.

Trypsin/creatinine clearance ratio--a recently proposed screening test for pancreatic cancer--was assessed in 45 subjects (17 control subjects, 15 patients with pancreatic cancer, and 13 with chronic pancreatitis). A statistically significant increase of the ratio was detected not only in pancreatic cancer, but also in chronic calcifying pancreatitis. Thus, the previously reported clinical usefulness of the test in pancreatic cancer diagnosis was not substantiated by the present data. Although not fully investigated as yet, reasons for an abnormal ratio are probably independent of the neoplastic or inflammatory nature of the pancreatic disease. Science renal enzyme excretion (alpha-glucosidase, gamma-glutamyltranspeptidase, leucine aminopeptidase) was not found to be invariably elevated when trypsin/creatinine clearance ratio was increased, tubular damage cannot be assumed as constituting the only reason for an altered clearance ratio.

Adult

[Clinical importance of the determination of antithrombin III by the use of a chromogenic substrate, in cases of disseminated intravascular coagulation and of acute hepatic insufficiency].

Antithrombin III (AT III) an alpha 2 globulin produced by liver, is the most important plasmatic inhibitor of activated coagulation factors, that bind irreversibly to it with formation of inactive complexes. Therefore, when coagulation processes are activated in vivo, a decrease of AT III is presumably likely to occur. In the present research, AT III has been determined both as substance concentration, by radial immunodiffusion, and on the base of its activity on a chromogenic substrate (Chromozym) in patients with DIC before and after heparin therapy. Some patients with acute liver insufficiency have been similarly studied, because they not only have a deficient protein synthesis but also show phenomena of anticoagulative factors consumption. In all the patients, the AT III levels appeared decreased by both methods; the decrease of activity was comparatively much more intense and in a case no activity was even detectable.

Antithrombin III

Improved direct specific determination of serum iron and total iron-binding capacity.

Serum iron is released from transferrin and reduced at pH 1.7 by treating serum with a 10 g/L ascorbic acid solution in 0.1 mol/L HCl. When ferrozine is added to this reagent, it forms a complex with iron that is as intensely colored as at higher pH values, and under these conditions no turbidity is produced. The second major interference, that from copper, is eliminated by adding 1 g of thiosemicarbazide per liter, which at a low pH forms a stable, uncolored complex with copper without affecting the reaction of ferrozine with iron.

Ascorbic Acid

Heparin interferes with albumin determination by dye-binding methods.

Heparin, when added in vitro at rather high concentrations (400--1000 kilounits/L) as an anticoagulant, interferes with albumin determination by bromcresol green by forming an insoluble precipitate with this dye. The interference is much less with bromcresol purple. It can be abolished by addition of hexadimethrine bromide.

Autoanalysis

A new look at the measurement and interpretation of enzyme assays.

Some methodological problems in clinical enzymology, including instability of enzymes in the incubation mixture and requirements for optimal reaction conditions, are highlighted. The importance of a knowledge of fundamental enzyme biochemistry and physiology as the basis for their diagnostic application is stressed, and the different behaviour of some hepatic enzymes--namely, GOT, GPT, gamma-GT, and OCT, in various pathological conditions is traced back to their characteristic biochemical and physiological properties. In the field of urinary enzymes a knowledge of the ideal requirements for the enzyme investigation of the various renal functions and of the properties of potentially valuable enzymes permits a critical selection of the really useful ones.

Alanine Transaminase

Chemical and pharmacological investigations of constituents of Eleutherine bulbosa (Miller) Urb. (Iridaceae).

Eleutherin and eleutherol extracted from bulbs of Eleutherine bulbosa (Miller) Urb. (Iridaceae), collected in the Amazonian jungle and grown in Italy, were tested for biological properties. The extraction procedure and the results of antibacterial, cytotoxicity, and pharmacological assays are reported. Eleutherin has a weak and transient effect of decreasing the prothrombin time (in vivo in rats) and a weak antibacterial activity on Bacillus subtilis (in vitro).

Analgesics

[Diagnostic value of determination of urinary enzymes].

Criteria to be followed, according to the AA., when choosing urinary enzymes to be determined for the evaluation of the anatomical and fuctional situation of kidney, are discussed. These criteria are essentially based on the localization of these enzymes in the organism and on their molecular dimensions. The behaviour of some enzymes, more or less strictly adhering to these criteria, is considered, in relation to glomerular or tubular disfunctions or to parenchimatous lesions. The present and future possibilities of this kind of approach for the analysis of renal alterations are evaluated.

Acute Kidney Injury