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Biomedical subjects

S Barni

Publications and source records attributed to S Barni.

At least 199 records · Page 11Linked to original sources
PubMed1987

[Concomitant therapy with cisplatin and radiotherapy in locally advanced tumors of the cervico-facial area].

Nineteen patients with locally advanced head and neck cancer were treated from November 1983 to January 1986 with standard loco-regional Radiotherapy: 2 Gy for 5 days/week up to a total dose of 70 Gy and simultaneous Cisplatinum 20 mg/m2 weekly. All patients achieved a response: 10 (52%) obtained a complete remission (CR) and 9 (48%) a partial remission (PR). Four of 9 patients in PR after chemoradiotherapy were disease-free after radical resection of the residual masses, while another patient was completely cured after second-line chemotherapy. The overall CR was then 79% (15/19). The results were analyzed according to the nodal status and showed that: 92% (11/12) of patients with initial nodal involvement (N1-2) achieved a CR and 75% of them were disease-free after a median follow-up of 23+ months, while only 57% (4/7) of patients with advanced nodal involvement (N3) obtained a CR (p greater than 0.05; NS) and 28% (2/7) of them were alive without evidence of disease (p less than 0.05) after 4+ and 30+ months. Toxicity was moderate: nausea and vomiting (grade 2-3) occurred in about 50% of patients, mucosal toxicity (grade 1-2) in 58%. Myelosuppression was negligible. No patient developed renal failure. Weekly cisplatinum administration during radiotherapy deserves further study especially in the management of patients with advanced primary tumor and minimal lymph node involvement.

Adult↗
PubMed1986

Prolactin response to thyrotropin-releasing hormone in early and advanced human breast cancer.

While prolactin (PRL) has been shown to stimulate the development of mammary carcinoma in several animal species, its role in human breast cancer remains to be established. To further investigate PRL secretion in human breast cancer, its basal levels and response to thyrotropin-releasing hormone (TRH) were evaluated in 16 patients (6 with no metastases and 10 with metastatic locations). The control group consisted of 19 healthy women. High PRL basal concentrations were seen in 2 patients only; no significant differences were found between the other patients and the normal subjects. The PRL increase induced by TRH administration was significantly higher in patients than in controls. Finally a change in the hormonal secretion was found after chemotherapy in 3 of the 5 patients in whom PRL response to TRH was evaluated either before or 10-12 days after a cycle of intravenous CMF adjuvant chemotherapy. These results demonstrate the existence of an exaggerated response of PRL to TRH in patients with breast cancer, even in the presence of normal basal levels. Moreover, they would seem to suggest a possible influence of CMF on PRL response to TRH stimulation.

Adult↗
PubMed1986

Electron-cytochemical localization of succinic semialdehyde dehydrogenase activity in Purkinje neurons and hepatocytes of the rat.

A method is presented for the ultrastructural demonstration of succinate semialdehyde dehydrogenase (SSADH) activity in cerebellar Purkinje neurons and liver hepatocytes; SSADH is an enzyme involved in the degradation of gamma-aminobutyric acid (GABA). Incubation media originally used for light microscopy were considered. Reaction products were mainly detected when fresh tissue was used. In Purkinje cells, grains ascribable to SSADH activity were localized on the mitochondria (especially on the outer membrane); some extramitochondrial formazan deposits were also found. After brief fixation by immersion or perfusion, only a few formazan granules were detected in the cytoplasm. A similar distribution pattern was observed in hepatocytes, in which extramitochondrial grains and grains on the nuclear membrane were frequent. The actual existence and the possible meaning of extramitochondrial SSADH activity is critically discussed on the basis of the data in the literature.

Animals↗
PubMed1986

The annual cycle of Erinaceus europaeus L. as a model for a further study of cytochemical heterogeneity in Purkinje neuron nuclei.

The cytochemical heterogeneity of nuclei in Purkinje cells, which reflects differences in metabolic states within the population, has been studied by comparing cerebellar hemispheres of the hedgehog during periods of activity and hibernation. Cerebellar granule cells and hepatocytes served as controls for diploid cells. Three different cytochemical stains (Feulgen reaction, Propidium iodide and Hoechst 33342 fluorochromes) were used in order to evaluate by microdensitometry and microfluorometry how much the heterogeneity is dependent on the variations in DNA content and degree of chromatin compaction. In the active period, Feulgen-DNA values of Purkinje cells were more widely dispersed than in control cells. Some values (18-40% of the population) exceeded (hyperdiploid) the diploid value. With Propidium iodide and Hoechst 33342 (under conditions for quantitative evaluation of DNA), a few values also exceeded the maximum value for control cells. We conclude that there is nuclear heterogeneity (diploid-hyperdiploid) in the Purkinje neuron population during normal activity. The percentage of hyperdiploid nuclei changes according to the technique used; in particular, the comparison of the different stains indicates that a different chromatin compaction is mainly responsible for hyperdiploid Feulgen-DNA values, but in a few hyperdiploid cells there is an actual surplus of DNA. In view of the modalities of detection of DNA by the different cytochemical approaches utilized, this may be mainly single-stranded DNA. During hibernation nuclear heterogeneity is still present in Purkinje neurons, but with a shift of the distribution towards lower values; hyperdiploid nuclei were not detected with all the procedures used. Moreover, when Propidium iodide is used at the concentration suitable for qualitative studies, the dye intercalation is lower than during activity. Data suggest that both decreased DNA and increased chromatin compaction occur in Purkinje cells, thus pointing to a lower metabolic activity of these neurons in hibernating animals. The changes in diploid granule cells were always less than those in Purkinje neurons and could be ascribed to a further increase in chromatin compaction only, not requiring changes in DNA content.

Animals↗
PubMed1985

Morphohistochemical changes in hepatocytes during the life cycle of the European eel.

The comparative analysis of morphological, histochemical and cytochemical patterns of eel (Anguilla anguilla L.) hepatocytes reveals clear differences between two stages of its life cycle, i.e. the trophic stage (yellow eel) and reproductive stage (silver eel). The storage of glycogen prevails in the yellow eel, whilst lipids appear to be remarkably increased in the silver eel, in which some hepatocytes also show glycogen-rich areas. Generally, in the silver eel dehydrogenase and acid phosphatase activities seem greater and different distribution of the reaction products is present; on the contrary, a lower G6PDH activity is observed. The electron microscopy characteristics and distribution of both cellular organelles and reserve materials reflect the modifications found at light microscopy. The ultrastructural patterns provide further evidence for the heterogeneity of liver parenchyma in silver eel. In particular, the coexistence of nuclei showing a different degree of chromatin compactness is also accounted for by the quantitative cytochemical data on the nuclear DNA after Feulgen reaction and intercalation with propidium iodide at low and high concentrations. With regard to the DNA content, the hepatocytes in the silver eel as well as in the yellow eel are mainly 2c. However, some 4c values are also found, which according to the literature can be ascribed to cells in G2 phase. The present data may express the onset of different functional requirements during the reproductive stage in comparison with the trophic one. Moreover, our results are consistent with modifications found by other authors as a consequence of interruption of nourishment and during gonad maturation, i.e. two phenomena characterizing the transition from yellow to silver eel.

Acid Phosphatase↗
PubMed1985

Growth and polyploidization of the liver of early postnatal rats treated with bleomycin.

Bleomycin was administered to 6- and 10-day-old rats and its effects were examined after a two-week survival period. Decreases in body weight and some phenotype abnormalities occurred in both age groups. Decreased relative liver weight (g/g b.w.) was observed only in animals injected on PD 10. DNA microdensitometry and microfluorometry (Feulgen reaction and Hoechst 33342 staining) revealed an increase in the frequency of intermediate DNA values in animals injected on PD6 and killed on PD20. In older animals, i.e. in rats injected on PD10 and killed on PD25, increases in 4c mononucleate and 8c binucleate cells and also a reduction of the relative number of binucleate cells appeared, as compared with age-matched controls. In both age groups, karyological abnormalities, including micronucleate cells and imbalanced DNA content in binucleate cells, were observed.

Aging↗
PubMed1985

Comparative aspects of circulating erythrocytes in the trophic and reproductive phases of European eel. Ultrastructure and cytochemistry.

Different cytochemical and morphological parameters were used to compare the functional patterns of the erythrocytes in the transition from the trophic (yellow eel) to the reproductive (silver eel) phases of European eel (Anguilla anguilla L.). Data on the nucleus were obtained by microdensitometric (Feulgen reaction) and cytofluoremetric (propidium iodide and Hoechst 33342 fluorochromization) evaluations of DNA staining intensity. In the silver eel, chromatin condensation was more heterogeneous and chromatin also appeared to be looser. The fluorochromes provided information on the different degrees of organization of the chromatin filament, with regard to both primary and higher order DNA structure. In the silver eel, the fine structure showed a higher number of erythrocytes with large euchromatinic areas and the heterochromatinic component was occasionally present in scattered clumps. As for the cytoplasm, in the silver eel a positive correlation could be established between the presence of intact cytoplasmic organelles (mitochondria, Golgi complexes, ribosomes, etc.) and the high fluorescence intensity. This aspect is revealed through the detection of definite membrane components such as glycoconjugates and primary amino groups (PAS reaction and fluorescamine staining, respectively). All these findings allowed us to establish that the transition from the trophic to the premigratory reproductive phase is marked by a higher heterogeneity of the erythrocytes, due to different cell maturation levels. This fact can be ascribed to different metabolic requirements as well as to a more intense erythropoiesis, typical of the most active phase of the eel's life.

Aging↗
PubMed1985

On the heterogeneity of Purkinje neurons in vertebrates. Cytochemical and morphological studies of chromatin during eel (Anguilla anguilla L.) life cycle.

The relationship between the heterogeneity of Purkinje cell chromatin and the functional involvement of cerebellum has been analyzed comparing two stages of eel life cycle (yellow eel and silver eel) which are characterized by a different degree of swimming activity. The DNA content and the chromatin condensation have been studied by means of microdensitometry (Feulgen-DNA, Feulgen-DNA/area), microfluorometry (DNA after intercalation with Propidium Iodide at low and high concentration) and electron microscopy. In the transition from the yellow eel to the silver eel, the Purkinje cell heterogeneity undergoes variations. In the silver eel, which shows a higher swimming activity, high Feulgen-DNA and Propidium Iodide-DNA (H2c to 4c) were more frequent and a greater heterogeneity in the chromatin condensation was observed. In particular, the changes were more evident in the lobus vestibulolateralis; mainly in this area, which receives inputs from the lateral line, the Purkinje cells are scattered in the molecular layer. On the contrary, in the yellow eel these large cells occupy the zone near or within the granular layer. The data suggest a relationship between the degree of heterogeneity of Purkinje cells and the afferent systems of the cerebellar areas examined. The changes of cerebellar cytoarchitectonics may be expression of the higher degree of the swimming activity of silver eel.

Anguilla↗
PubMed1985

The use of propidium iodide in cytochemical studies of interphase chromatin structure.

Different cytochemical conditions of using Propidium Iodide, a phenanthridinic fluorochrome specific for double-stranded nucleic acids, have been considered to study some structural aspects of the interphasic chromatin. Some molecular properties of the dye allow to define the structure of chromatin fibre (degree of condensation) by means of thermal denaturation of DNA, fluorochromization after extraction of different chromatin components and fluorochromization in condition of low dye-substrate molar ratio (relative unsaturation of DNA). Different biological situations such as cell specialization, neoplastic transformation and life cycles have been examined choosing some typical models (hepatocytes, nucleated erythrocytes, lymphocytes, endometrial cells).

Animals↗
PubMed1984

Cytochemistry of cell surface sialoglycoconjugates in endometrial adenocarcinoma. Effects of medroxyprogesterone therapy.

Ferritin- and rhodamine-conjugated Limulus polyphemus agglutinin was used to localize, by electron microscopy, and to quantify, by microfluorometry, the cell surface sialoglycoconjugates in human endometrial adenocarcinoma before and after medroxyprogesterone acetate therapy. In the untreated tumor the lectin labelling was irregularly distributed on the cell surface, with a maximum density at the apical area and at the intercellular border; high values of the density-binding sites on cell surface were also detected by cytofluorometry. The binding pattern in both electron microscopy and microfluorometry on normal tissue and on tumor tissue submitted to medroxyprogesterone acetate stimulation appeared clearly modified; the lectin labelling concerned the apical areas only (also after treatment with chelating agents), with low fluorometric values of the reactive site density. The differences found in the lectin binding to the cellular sialic acid residues may be due to sialoglycoconjugate quantitative changes and/or to their different reactivity resulting from alterations of the cell membrane architecture. The data appear also correlated with a different proliferative activity and ploidy level of the three situations analyzed.

Adenocarcinoma↗
PubMed1983

Methodological problems in the histochemical demonstration of succinate semialdehyde dehydrogenase activity.

Methodological aspects of the histochemical technique for the demonstration of succinate semialdehyde dehydrogenase activity (EC 1.2.1.24) (indicative of the degradative step of gamma-aminobutyric acid catabolism) have been analysed in rat Purkinje neurons, where gamma-aminobutyric acid has been shown to be a neurotransmitter, and in hepatocytes, where it is metabolized. During a histochemical incubation for the enzyme, artefacts of succinate dehydrogenase activity and the 'nothing dehydrogenase' reaction are produced. Inhibition of these artefacts by the addition of two inhibitors, malonate and p-hydroxybenzaldehyde, revealed specific reaction products. Formazan granules, which can be ascribed only to specific succinate semialdehyde dehydrogenase activity, are obtained by adding malonate to the incubation medium in order to inhibit both succinate dehydrogenase activity and nothing dehydrogenase. The formation of these granules is completely inhibited by p-hydroxybenzaldehyde, an inhibitor of succinate semialdehyde dehydrogenase activity. Different levels of succinate semialdehyde dehydrogenase activity were noted in Purkinje neurons. This activity was also found in hepatocytes, mostly in the portal area, but with a lesser degree of intensity and specificity. Indeed, non-specific formazan granules were still produced, because of the 'nothing dehydrogenase' reaction, even in the presence of malonate. Thus, a malonate-insensitive 'nothing dehydrogenase' reaction seems to be present in neural and hepatic tissues.

Aldehyde Oxidoreductases↗
PubMed1983

Cytofluorometric study of the erythrocyte glycoconjugates content in different species of vertebrates.

The PAS-positive material was measured by cytofluorometry in peripheral circulating erythrocytes of 22 species from different classes of Vertebrates. The following parameters were considered: total fluorescence intensity per cell, concentration index, fluorescence fading. The highest variability of concentration indexes was found in Fishes with a minimum in the more active swimmers (Scylliorhinus and Salmo); this fact may be related to a more intense erythropoiesis. The values were more homogeneous in the Amphibians, Reptiles, and Birds, the difference never exceeding 1/2 between the maximum and minimum values. The lowest concentration indexes were found in Mammals, a class with very specialized and enucleated erythrocytes: the data appear rather heterogeneous with a minimum in Macaca. The patterns of fluorescence fading suggest a biochemical homogeneity of the PAS-positive erythrocyte material in the species considered. This fact might indicate the presence of a fundamental biochemical component possibly linked to different structures of the red cells.

Amphibians↗
PubMed1983

Chromatin organization in frog Purkinje neurons during the annual cycle: cytochemical and ultrastructural studies.

Feulgen-DNA microdensitometric and propidium Iodide-DNA (PI-DNA) microfluorometric evaluations were made in Purkinje cells of cerebella from hibernating frogs and from active frogs. Higher Feulgen-DNA/distribution area ratios and lower PI-DNA values were found in the hibernating frog (both at high and low fluorochrome concentrations). These data indicate a higher degree of chromatin compactness. During the activity period, the Feulgen-DNA/distribution area ratios are lower and the Feulgen-DNA content is higher; the corresponding higher PI-DNA values indicate a lower degree of chromatin condensation. Histochemical and ultrastructural data show clearly different distribution patterns of chromatin and ribosomes in the two periods. The overall results underscore lower activity of neurons and a greater homogeneity within the Purkinje cell population during hibernation.

Animals↗
PubMed1983

Effects of diphenylhydantoin on postnatal ontogenesis in the rat. Ultrastructural analysis of Purkinje neurons and hepatocytes.

An ultrastructural analysis of Purkinje neurons and hepatocytes was carried out at several stages of postnatal ontogenesis in rats born from dams administered diphenylhydantoin (DPH) during pregnancy and nursing. After DPH administration the signs of immaturity in the neurons both at cytoplasmic and nuclear level were particularly evident between the 4th and 17th day of postnatal life, while at the end of histogenesis the normal situation was recovered. Such delayed morphological maturation of the neurons is in agreement with the data showing that anticonvulsant drugs given during pregnancy slow down postnatal growth and mental development. At all stages examined, modifications, mainly concerning the distribution of glycogen and the increase in rough endoplasmic reticulum and free ribosomes, were also observed in hepatocytes. The examination of the placebo group revealed some signs of delayed maturation in Purkinje neurons at early histogenetic stages and some modifications of the normal pattern in the hepatocytes. The rôle of gastric tube in drug administration needs to be verified further.

Animals↗
PubMed1982

[Association of laparoscopy and bone marrow biopsy in the staging of small-cell undifferentiated carcinoma of the lung. Evaluation of 116 consecutive cases].

116 consecutive patients with small cell anaplastic carcinoma of the lung had laparoscopy with multiple liver biopsies and bone marrow biopsy, performed as a staging procedure. Bone marrow biopsy was positive in 13 patients (11.2%); no significant rise in percent was seen when bilateral specimens were obtained. Laparoscopy was positive in 17 patients (14.6%); one patient had extrahepatic involvement only. Liver scan did not show high correlation with laparoscopy: 6 patients out of 11 had negative liver scan with metastases demonstrated at laparoscopy. Only 6 patients had laparoscopy positive along with bone marrow biopsy (5.1%). At determination of the stage, 12 patients out of 78 (15.3%), with apparently localized disease had diffuse disease after the two procedures. Laparoscopy and bone marrow biopsy were positive in 12 patients out of 38 (31.5%), when the disease was diffuse at diagnosis. 7 patients had liver metastases at diagnosis, which were excluded after laparoscopy. Laparoscopy and bone marrow remain valuable procedures in assessing stage in small cell anaplastic carcinoma of the lung, because of their high rate of stage modifications due to their combined employment at diagnosis.

Adolescent↗
PubMed1981

Propidium iodide as a probe for the study of chromatin thermal denaturation in situ.

The possibility of using propidium iodide, a phenanthridinic fluorochrome specific for double-stranded nucleic acids, for the study of chromatin thermal denaturation in situ has been examined. Smears of lymphocytes and hepatocyte nuclei from 15-day-old rats were fixed in acetic acid--ethanol (1:3 v/v), treated with RNAse and submitted to different protein extraction procedures, namely, incubation with pepsin, trypsin and sodium chloride. Denaturation experiments were performed in Sörensen buffer at pH 7.4 containing 10% formamide at temperatures between 27 and 95 degrees C. The samples were stained with propidium iodide and mounted in buffer or glycerol. Measurements were performed with a microfluorometer at a wavelength of 446 nm. The results indicate a higher thermostability of lymphocytes as compared to hepatocytes. The denaturation pattern suggests a certain organization complexity of chromatin, better emphasized by the derivative curves which show the presence of at least three fractions with different melting points. After protein extraction, the denaturation curves exhibit a somewhat simplified pattern, with the disappearance of the most stable peak in the derivative curves. The samples mounted in glycerine exhibit a better stability of staining with time, and an increased quantum efficiency of the fluorochrome with regard to those mounted in buffer. These data confirm the importance of protein--DNA interactions in the organization of chromatin and point to some differences, depending on the cell type and on functional activity.

Animals↗