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A Mosca

Publications and source records attributed to A Mosca.

At least 55 records · Page 3Linked to original sources
PubMed1995

A patient-side technique for real-time measurement of acetylcholinesterase activity during monitoring of eptastigmine treatment.

Rapid and reliable measurement of acetylcholinesterase (AChE) activity is of crucial importance to the pharmacodynamic monitoring of anticholinesterase drugs. A new assay has been developed to measure AChE from 10 microliter samples of capillary blood. AChE activity was calculated from the change in pH of the reaction medium caused by the hydrolysis of acetylcholine and measured with a highly sensitive differential pH apparatus (CL-10, Eurochem, Rome, Italy). Interference by butyrylcholinesterase was eliminated by a specific inhibitor, quinidine sulfate. The assay lasts 1 min. The coefficient of variation (CV) for replicated measurements was 2.8% (3267 U/L, n = 33). Linearity ranged from 0 to 10,000 U/L. The correlation coefficient between the new technique and Ellman's colorimetric method on washed erythrocytes was r = 0.987 (y = 1.299x - 63, n = 29). The correlation coefficient between assays on capillary and venous samples was r = 0.979 (y = 0.974x + 174, n = 47). A cross-laboratory validation study was performed in 10 centers using glycerol-stabilized hemolysates with normal and reduced AChE activity. Samples were assayed in triplicate. The within- and between-laboratory CVs for samples with normal AChE activity (6,018 U/L) were 2.2 and 8.1%, respectively. The new method was applied to a double-blind, placebo-controlled multicenter study of eptastigmine in Alzheimer patients and proved to be a simple, noninvasive, rapid, and reliable method for pharmacodynamic monitoring of this drug.

Acetylcholinesterase↗
PubMed1994

Possible significance of antibodies to Legionella pneumophila in HIV-1 infected patients with acute respiratory illness.

Eighty-six serum samples from 52 HIV-1 infected patients with complicating pneumonia illness were assayed for the presence of antibodies to Legionella pneumophila. In 25 of these patients Pneumocystic carinii has been previously diagnosed. Among all patients investigated only 4 had antibodies to L. pneumophila of significant titer of 128. In one patient L. pneumophila was demonstrated coexisting with P. carinii. Despite of a small proportion of patients with a significant titer of antibodies against L. pneumophila, the presence of this microorganism should be carefully investigated in AIDS patients with complicating pneumonia especially when the aetiological diagnosis is not defined; the reason is to improve the therapeutic treatment.

AIDS-Related Opportunistic Infections↗
PubMed1994

Transitional papillary cell carcinoma of the ureter: a histological and ultrastructural study.

We report a case of transitional papillary carcinoma of the distal left ureter. The histological and ultrastructural features were seen and compared by SEM and TEM. Observations confirm the data of literature that the deep cells of neoplasm are a normal morphological finding while the superficial cells do not have the characteristics present in normal transitional cells. In addition, SEM shows small groups or single cells with "pleomorphic microvilli" on the cell surface. These, in ureter, confirm the studies of many authors who have observed these abnormalities in carcinomas of several organs like breast, colon, liver and mesothelium.

Aged↗
PubMed1993

Determination of heptylphysostigmine in plasma by high-performance liquid chromatography with electrochemical detection.

Heptylphysostigmine is a new and very promising cholinergic drug for the treatment of Alzheimer disease. A method has been developed for its determination in plasma with a detection limit of 50 pg/ml. The drug was extracted in n-hexane by a simple one-step procedure, after buffering with sodium bicarbonate. Samples were analysed on a 25 cm x 4.6 mm I.D. silica column (5 microns particle size) using a mixture of acetonitrile, methanol and ammonium nitrate as mobile phase. Since this molecule is quite unstable in plasma, pyridostigmine bromide was added to samples to limit the decomposition. Physostigmine was employed as internal standard. The molecule was electrochemically detected by oxidizing potential (+0.75 V). The method was applied to the analysis of blood samples taken from one healthy volunteer administered this drug. In the same subject the inhibition rate of acetylcholinesterase in plasma and red cells was also measured.

Acetylcholinesterase↗
PubMed1993

Pharmacodynamics and pharmacokinetics of eptastigmine in elderly subjects.

Eptastigmine is a new cholinesterase inhibitor, which may be potentially useful for the symptomatic treatment of Alzheimer's disease. A preliminary evaluation of its pharmacodynamic and pharmacokinetic profiles in the elderly has now been made in 6 healthy subjects (63-84 years of age) given 30 mg eptastigmine as a single oral dose. Blood was collected prior to and 1, 2, 3, 4, 6, 8, and 12 h after eptastigmine administration for measurement of cholinesterase inhibition in plasma and red blood cells and the plasma drug concentrations. The maximum plasma cholinesterase inhibition was 17%, which was reached 2.7 h after treatment. In red cells the maximum inhibition of the enzyme was 29% after 3.8 h. The estimated half-time of cholinesterase recovery was 12.4 h in plasma and 13.6 h in red blood cells. The peak plasma concentration of eptastigmine of 0.86 ng.ml-1 was reached after 1.4 h. Following absorption the drug was rapidly distributed into tissues (t1/2 alpha = 0.44 h) and then eliminated with a half-life of 12.1 h. The drug was well tolerated in all but one subject, who showed bradycardia with hypertension and nausea for about 2 h after the dose. The results indicate that oral administration of eptastigmine to elderly subjects produces long lasting inhibition of cholinesterase activity in plasma and in red blood cells.

Administration, Oral↗
PubMed1993

Rapid potentiometric determination of cholinesterases in plasma and red cells: application to eptastigmine monitoring.

Eptastigmine (MF 201) is a new physostigmine derivative with potent inhibitory activity on cholinesterases. Here we present a new potentiometric cholinesterase activity assay suitable for MF 201 monitoring. The analysis is performed on a differential pH system and has the following characteristics: (a) within-run precision: C.V. 2.0% (plasma cholinesterase), 1.8% (red cell cholinesterase); (b) between-run precision: C.V. 4.0% (plasma cholinesterase); (c) linearity: 1-10 kU/l (plasma cholinesterase), 6-70 U/g Hb (red cell cholinesterase); (d) comparison with a reference method (x, HITACHI 737 Boerhinger Mannheim, Italy): y = 0.785x - 0.07; n = 37; r = 0.998. The assay has been applied to the determination of plasma and red cell cholinesterase activity in volunteers over 60 years of age treated with a single oral dose of 30 mg eptastigmine. We found that red cell cholinesterase is selectively inhibited after MF 201 administration with the following kinetics (time, % of inhibition, mean +/- S.E., n = 6): 0 h, 0; 1 h, 17 +/- 4.6; 2 h, 24 +/- 4; 4 h, 23 +/- 4.4; 12 h, 14 +/- 3. Eptastigmine plasma levels were also determined by a HPLC method: maximum concentration was found one hour after drug administration.

Administration, Oral↗
PubMed1993

UV red fluorescence of Eubacterium lentum.

Twenty-nine clinical isolates of Eubacterium lentum and two type species were evaluated for the ability to fluoresce under UV light. Twenty-one of the 29 isolates and both of the reference strains showed orange-to-red fluorescence. This fluorescence did not require blood or hemin in the culture media and did not fade upon air exposure. The fluorescent pigment, after extraction by 1 N NaOH, showed peak excitation at a wavelength of around 400 nm. The capacity of E. lentum to produce fluorescence may be a useful and time-sparing laboratory aid for its identification.

Culture Media↗
PubMed1993

Introduction of magnetic beads in diagnosis: a simple and rapid method to detect mutations of beta globin gene, directly amplified from blood.

In this communication we present the results obtained by the use of magnetic beads in diagnosis, for the identification of genetic variants at the molecular level by sequencing, in comparison with the more laborious method of the production of ssDNA with asymmetric PCR. We compared the two techniques studying variants of beta globin gene: Hb Abruzzo [beta 143 (H21) His -> Arg] and Hb D Los Angeles [beta 121 (GH4) Glu -> Gln].

Base Sequence↗
PubMed1993

Influence of short-chain fatty acids produced by anaerobic bacteria on procoagulant activity produced by Escherichia coli and Bacteroides fragilis-stimulated leucocytes: possible role in intra-abdominal abscess formation.

The effect of selected short-chain fatty acids (SCFA) produced by anaerobic bacteria on the production in vitro of procoagulant activity (PCA) by human mononuclear cells stimulated by either Escherichia coli or Bacteroides fragilis which are common pathogens in intra-abdominal infections was investigated. In particular, acetic, propionic, succinic, butyric, and isobutyric acids were evaluated. Acetic, butyric, and isobutyric acids were able to inhibit significantly the production of PCA by bacteria-stimulated mononuclear cells. Since the production of PCA leads to the deposition of fibrin which is considered critical to the establishment of intra-abdominal abscesses, the inhibitory effect exerted by SCFA present in the inflammatory environment might play an important modulating role in the development of abscesses complicating intra-abdominal infections.

Bacteroides fragilis↗
PubMed1993

Rapid determination of erythrocyte pyruvate kinase activity.

We report a new potentiometric method for determining pyruvate kinase (PK). Enzymatic activity is measured by monitoring the change in pH produced in the reaction buffer under International Committee for Standardization in Haematology (ICSH) standardized assay conditions, and the lactate dehydrogenase reaction is automatically subtracted in each measuring cycle. The analysis, performed at 37 degrees C, requires a 10-microL sample (isolated erythrocytes or whole blood) and is completed in 2.5 min. The intra-assay CV is < 4% (PK between 3 and 35 U/g Hb); the interassay CV is 4.0% (PK 15 U/g Hb); results are linear from 3 to 30 U/g Hb. A good correlation with the ICSH reference method (x) was found: y = 1.011x - 0.05; n = 32; r = 0.9939; Sylx = 0.75 (units: U/g Hb). The reference intervals of the PK activity in isolated erythrocytes (RBC-PK) were estimated in 89 normal subjects. We found that women possess a higher RBC-PK than do men (P < 0.0001) and that the biological variability (CVb) of RBC-PK is 13.5%. Applications of the proposed method to the hematological routine are reported.

Adolescent↗
PubMed1992

Heterozygous beta-thalassemia: relationship between the hematological phenotype and the type of beta-thalassemia mutation.

In this study we have correlated the severity of the hematological features to the type of the beta-thalassemia mutation [codon 39 (C----T), IVS-I nt 110 (G----A), IVS-I nt 1 (G----A), IVS-I nt 6 (T----C), IVS-II nt 745 (C----G), -87 (C----G) and beta 6 (-1 bp)], in a group of beta-thalassemia heterozygotes of Italian descent in whom we excluded the presence of iron deficiency or deletion alpha-thalassemia. The beta-thalassemia mutation was defined by dot blot analysis on amplified DNA with allelic specific oligonucleotide probes. We found that a) heterozygotes for beta+ IVS-I nt 6 and beta+ -87 mutations produce larger and better hemoglobinized red blood cells, and b) heterozygotes for beta+ IVS-I nt 6 and beta+ IVS-I nt 110 mutations have a less marked increase of Hb A2 levels as compared to heterozygotes for the other mutations investigated. These findings indicate that milder beta-thalassemia mutations such as the beta+ IVS-I nt 6 and beta+ -87, express also in the heterozygous state a milder phenotype as compared to beta o-thalassemia or severe beta+ thalassemia (beta+ IVS-I, nt 110). The Hb A2 levels, on the other hand, were not related to the severity of the mutation because of less marked increase was found in a mild (beta+ IVS-I nt 6) as well in a severe (beta+ IVS-I nt 110) mutation. From the practical point of view these findings should be adequately considered in carrier screening and genetic counselling.

Adult↗