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Biomedical subjects

S Biagioni

Publications and source records attributed to S Biagioni.

At least 37 records · Page 2Linked to original sources

Cholinergic markers are expressed in developing and mature neurons of chick dorsal root ganglia.

The presence of acetylcholinesterase has been reported in chick dorsal root ganglia at early developmental stages although acetylcholine is not known to play a role in these ganglia. Recently, we reported that during development the level of acetylcholinesterase increases continuously and the enzyme becomes gradually expressed in all sensory neurons. These observations prompted the study of the developmental pattern of expression of other cholinergic markers, such as choline acetyltransferase (ChAT) and the high affinity transport mechanism for choline. ChAT activity is barely detectable at early developmental stages (E7) and increases markedly thereafter, with an activity profile similar to that described for acetylcholinesterase. A similar increase in enzyme activity is also observed when ChAT is measured in dorsal root ganglia explants and in dissociated cells in culture. The study of ChAT activity in cultured cells shows an increase over a period of 3 days, thus ruling out the hypothesis that motor fibers, still associated to the ganglia, may represent a possible source of the enzyme. Immunostaining of whole ganglia or cultured cells shows that ChAT immunoreactivity is not restricted to a specific neuronal sub-population but appears as a common marker of sensory neurons. High affinity choline uptake, blocked by hemicholinium, is present in sensory neurons cultured from E7 dorsal root ganglia. Observations on cultured neurons from later stages (E18) indicate that choline transport is not a transient property of sensory neurons. These observations show a similar pattern of expression of several cholinergic markers during development. Such a pattern is maintained at significant levels also in mature ganglia.

Animals↗

Acetylcholinesterase distribution in subpopulations of murine thymocyte.

The presence of acetylcholinesterase has been detected in the thymus of several species both biochemically and histochemically. In this study we have investigated the molecular forms and the level of this enzyme in separate compartments of the murine thymus and in different thymocyte subpopulations. Similar levels of acetylcholinesterase activity are present both in thymocytes and in the stromal component. Sucrose density gradient analysis revealed the presence of a single molecular form of about 5 S, presumably a dimeric form. Moreover the results demonstrate a preferential association of AChE with mature thymocyte subsets (Peanut Agglutinin negative and Corticoresistant). This finding correlates with the preferential sensitivity of these cells to cholinergic drugs and supports the hypothesis that acetylcholinesterase modulates the cholinergic effects on thymocytes.

Acetylcholinesterase↗

Ferritin and transferrin levels in human breast cyst fluids: relationship with intracystic electrolyte concentrations.

The concentrations of sodium and potassium and the content of ferritin and transferrin, proteins considered as potential markers for identifying cells undergoing divisional activity, were measured in fluid from 30 human breast cysts. On the basis of the relative electrolyte concentrations, two main classes of cysts were defined. When the cyst fluids were subdivided according to their Na+/K+ ratio, a significant difference was found between menstruating vs. menopausal patients. The relationship between the two major iron-binding proteins and the Na+/K+ ratio may indicate the expression of a local higher biosynthetic activity in apocrine cysts associated with higher cancer risk.

Body Fluids↗

Acetylcholinesterase in the development of chick dorsal root ganglia.

Acetylcholinesterase is expressed in chick dorsal root ganglia neurons very early in development. Since the physiological role of the enzyme in these cells is still obscure, it appeared of interest to investigate its modifications in the course of development. The specific activity of acetylcholinesterase in chick dorsal root ganglia increases, during in ovo development, from day E5 to day E13; after day E13 there is a decrease. Conversely, when acetylcholinesterase activity was expressed on a per ganglion basis, a continuous increase in the level of the enzyme until day E20 was observed. Acetylcholinesterase is a polymorphic enzyme and its molecular forms have different cellular localizations. Two globular forms, a tetramer (G4) and a dimer (G2), are present in the ganglia, as in chick brain. G4 is the major form at day E5, where it represents about 85% of the activity. This form shows a progressive decrease since day E8, and at day E20 exhibits activity levels similar to those of G2. It is known that acetylcholinesterase-producing cells are also able to release the enzyme in the extracellular space. We determined the release of acetylcholinesterase by cultured dorsal root ganglia neurons at various developmental stages: acetylcholinesterase release is significantly increased at day E20, as compared to younger stages, and 90% of the enzyme released is G4.

Acetylcholinesterase↗

Lactate dehydrogenase, isoenzyme patterns and cation levels in human breast gross cyst fluid.

In order to investigate the diagnostic and/or prognostic value of total activity and isoenzymatic patterns of lactate dehydrogenase, 24 human breast gross cystic fluids were studied. A comparison of total lactate dehydrogenase activity to the serum level revealed an increased activity in about 63% of the cases examined; moreover, a significant increase in the slow-moving lactate dehydrogenase 4 and 5 isoenzymes was observed in some cyst fluids. The levels of Na+ and K+ concentrations were also analyzed and two classes of cysts were identified: one presenting Na+ and K+ levels similar to those found in extracellular compartment; the other with high K+ and low Na+ levels, characteristic of an intracellular fluid. This latter pattern could indicate an active metabolism of the epithelial cells lining the cysts. This breast cyst fluid also showed increased levels of lactate dehydrogenase 4 and 5 isoenzymes. The correlation between an increased activity of lactate dehydrogenase 4 and 5 isoenzymes and high K+ and low Na+ levels could be the expression of a high biosynthetic activity and of an anaerobic metabolism in some cysts, suggesting the evolution of the breast gross cyst lesion to malignancy. The importance of these observations is discussed.

Body Fluids↗

Expression of adult fast pattern of acetylcholinesterase molecular forms by mouse satellite cells in culture.

The pattern of acetylcholinesterase (AChE) molecular forms, obtained by sucrose gradient sedimentation, was studied at different in vitro developmental stages of myogenic cells isolated from adult mouse skeletal muscle. Only the globular forms were present in rapidly dividing satellite cells during the first days in culture. After myotube formation, a pattern similar to that described in mammalian fast-twitch skeletal muscle was observed. This pattern did not change during the following period in culture (up to 1 month) nor could it be modified by co-culturing with spinal cord motoneurons or by addition of brain-derived extracts. The internal-external localization of AChE molecular forms has been determined by the use of echothiophate iodide, a membrane-impermeant irreversible inhibitor of AChE. Echothiophate-treated cultures showed about 40% of both asymmetric and globular forms localized on the sarcolemma, with their active sites oriented outward. Analysis of culture medium from untreated cultures revealed the presence of both asymmetric and globular forms. When the same analysis was repeated on cultures of myoblasts derived from 16-day-old mouse embryos, the pattern of AChE forms was different. The myotubes derived from these cells exhibit a very small proportion of asymmetric form, which was not released into the medium. This pattern was not further modified during the following days of culture, nor by co-cultures with spinal cord motoneurons or by incubations with brain-derived extracts. Thus, the myotubes derived from myoblasts express in culture a clear phenotypic difference when compared to the corresponding myotubes from satellite cells, supporting the view that these two myogenic cells are endowed with different developmental programs.

Acetylcholinesterase↗

Muscle acetylcholinesterase in a familial myopathic disease.

Three sisters with myopathy characterized by different degrees of weakness, hypotonia, cramps and a significant hypertrophy of the calves underwent clinical tests. Laboratory examinations (nerve conduction velocity, electromyography and serum enzymes), serial histochemical analyses of muscle specimens and tests for muscular acetylcholinesterase (AChE) activity and its molecular forms were performed. AChE activities did not differ significantly from those of controls, while sedimentation patterns evidenced the disappearance of 16 S, 13 S and 10 S molecular forms in the elder sisters. The genealogical tree of the patients is described and their cases compared to those of others with calf hypertrophy reported in the literature.

Acetylcholinesterase↗

Alkaline phosphatase expression in human chorionic villi.

The physicochemical properties and electrophoretic mobility of different isoforms of alkaline phosphatase were studied in chorionic villi. Based on selective inactivation and inhibition studies (thermal stability, inactivation by urea, EDTA and L(+)ascorbic acid and L-amino acid inhibition), evidence was obtained for the existence of two distinct types of alkaline phosphatase in trophoblast cells. One type is peculiar to chorionic villi while the other is also found in term placenta. Both show two isoforms. These two isoforms were observed with polyacrylamide gel electrophoresis, carried out at pH 6.0 and 9.5. It is suggested that the qualitative and quantitative methods of alkaline phosphatase analysis could be used for first trimester fetal diagnosis of severe infantile hypophosphatasia and for understanding genetic control during early fetal development.

Alkaline Phosphatase↗

[Carcinoembryonic antigen in a review of cases in the literature].

Literature analysis of CEA serum levels tested in 21,147 patients, with non neoplastic and neoplastic disease of various organs, are reported. The sensitivity, the specificity, the positive and negative prognostic trend and the effective value of test in different pathologic situations are evaluated on the basis of organ localization and embryological origin.

Biomarkers, Tumor↗

Alpha 1-antitrypsin, transferrin, alkaline phosphatase, phosphohexoseisomerase and gamma-glutamyltransferase in breast cyst fluid.

The levels of alpha 1-antitrypsin, transferrin, alkaline phosphatase, phosphohexoseisomerase and gamma-glutamyltransferase were measured in 32 samples of breast cyst fluid, and a wide range of values was obtained. The levels observed in some samples for these parameters, being similar to those of normal serum, might suggest a mechanism of plasma exudation for the formation of breast cyst fluid. Nevertheless, a comparison with the maximum normal serum reference value revealed very high levels of gamma-glutamyltransferase in all of the samples; about 50% also exhibited high levels of phosphohexoseisomerase. These results indicate that the formation of breast cyst fluid takes place with a specific local production, in addition to the mechanism of selective plasma exudation. Moreover, elevated transferrin levels in some cyst fluids are probably the expression of a high biosynthetic activity and could be diagnostically useful in the course of breast gross cystic disease. The importance of these observations from the point of view of diagnostic and prognostic trends are discussed.

Adolescent↗

[Cervicovaginal cytology in women wearing intrauterine devices].

Cervical and vaginal smears in 300 women using (a) intrauterine devices (IUD) and in 300 age matched control subjects (b), have been examined. In women using IUD, endometrial cells have been observed also in the second half of menstrual cycle, conversely these cells are present in women belonging to the control group, just in the first half of the cycle. Pattern of cervico-vaginitis due to Chlamydiae, Actinomyces and Eubacteria have been observed in higher percentage in women IUD wearers 58% of (a) group and 19.3% of (b) group (P less than 0.005). These patterns have often been characterized by the presence of repair cells. Implications in the evaluation of vaginal smears are discussed.

Actinomycosis↗

[Cytology of breast cysts].

280 cytologic samples obtained by centrifugation of breast cyst fluids were studied. The results of the study on the cellular component and of the background are reported. The analysis was carried out on the cytomorphological aspects of the background, non epithelial cells, normal epithelial cells (foam, galactophoric, apocrine, papillary pictures) and malignant cells. Having described the single cytotypes, their diagnostic values in relation to other techniques are discussed.

Adolescent↗

Acetylcholinesterase molecular forms from rat and human erythrocyte membrane.

1. Some of the biochemical characteristics of acetylcholinesterase from rat and human erythrocytes were studied. 2. Both for rat and man two different acetylcholinesterase molecular forms were identified by gel electrophoresis. The faster moving form is less conspicuous and is not present in all individuals, therefore single-banded and double-banded preparations of red cell acetylcholinesterase can be obtained. The two components appear to be isomers of different molecular size (approximately Mr 150 000 and Mr 245 000) as estimated by gel electrophoresis at different polyacrylamide concentrations. 3. A single band, with a molecular weight of approximately 135 000, was obtained by sodium dodecyl sulphate gel electrophoresis. These results suggest that the faster moving form is a protomer and the slower a dimer. 4. The different sedimentation values obtained by density gradient centrifugation in the presence of Triton X-100 of double-banded (5.3S) and single-banded (6.3S) rat and human acetylcholinesterase preparations, are consistent with a protomer-dimer hypothesis. 5. The isoelectric pattern observed for both double- and single-banded preparations was similar for rat and man acetylcholinesterase and showed a considerable microheterogeneity (thirteen activity bands for rat and eleven for man with isoelectric values from 4.6 to 5.9).

Acetylcholinesterase↗

[Study of bisalbuminemias of the "fast" type].

A case of alloalbuminaemia of the fast type was described in a family living in the district of Pesaro. This was one of the few cases of this particular type and the first observed in this region. Being related to electrophoretic mobility, it is classified as: very fast, type gent. This anomaly has been evidenced by electrophoresis on cellulose acetate, while immunoelectrophoresis with an anti-protein total serum does not reveal the immunological differences referred to in normal albumine.

Adult↗

Acetylcholinesterase activity and molecular forms during denervation and reinnervation in extensor digitorum longus muscle of the rat.

The four principal molecular forms of acetylcholinesterase characteristic of the mammalian muscle (16.1 S., 12.5 S, 10.2 S, and 3.6. S) were identified by sucrose gradient sedimentation as the four activity peaks H, H1, M and L. After denervation obtained by crushing the sciatic nerve five stages of the denervation-reinnervation process were examined. Days 7, 14, 22, 30, and 60 were chosen on the basis of previous electrophysiological and histochemical studies. The AChE activity showed an initial drop followed by recovery after nerve arrival at the muscle which was completed by day 60. Marked changes in the relative proportions of the four molecular forms were observed. The 16.1 S almost disappeared during the denervation period, reappeared after nerve arrival and was completely restored at day 60. Changes were also observed in the intermediate and lower forms and were tentatively related to processes of degradation, reaggregation and de novo synthesis. A comparison of the present data with those from parallel electrophysiological and histochemical studies suggests the presence and the functional role of molecular forms other than 16S in the neuromuscular junction.

Acetylcholinesterase↗