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Biomedical subjects

S Coppola

Publications and source records attributed to S Coppola.

At least 37 records · Page 2Linked to original sources
PubMed2000

H2O2-induced block of glycolysis as an active ADP-ribosylation reaction protecting cells from apoptosis.

H2O2 treatment on U937 cells leads to the block of glycolytic flux and the inactivation of glyceraldehyde-3-phosphate-dehydrogenase by a posttranslational modification (possibly ADP-ribosylation). Glycolysis spontaneously reactivates after 2 h of recovery from oxidative stress; thereafter cells begin to undergo apoptosis. The specific ADP-ribosylation inhibitor 3-aminobenzamide inhibits the stress-induced inactivation of glyceraldehyde-3-phosphate-dehydrogenase and the block of glycolysis; concomitantly, it anticipates and increases apoptosis. Exogenous block of glycolysis (i.e., by culture in glucose-free medium or with glucose analogs or after NAD depletion), turns the transient block into a stable one: this results in protection from apoptosis, even when downstream cell metabolism is kept active by the addition of pyruvate. All this evidence indicates that the stress-induced block of glycolysis is not the result of a passive oxidative damage, but rather an active cell reaction programmed via ADP-ribosylation for cell self-defense.

Apoptosis↗
PubMed2000

Specific detection of Leuconostoc mesenteroides subsp. mesenteroides with DNA primers identified by randomly amplified polymorphic DNA analysis.

Randomly amplified polymorphic DNA analysis using primer 239 (5' CTGAAGCGGA 3') was performed to characterize Leuconostoc sp. strains. All the strains of Leuconostoc mesenteroides subsp. mesenteroides (with the exception of two strains), two strains formerly identified as L. gelidum, and one strain of Leuconostoc showed a common band at about 1.1 kb. This DNA fragment was cloned and sequenced in order to verify its suitability for identifying L. mesenteroides subsp. mesenteroides strains.

DNA Primers↗
PubMed2000

[Ovulation induction and the risk of ovarian tumors].

In the last years it has been observed a more and more increasing number of women submitted to therapies for induction of ovulation (disorders of the ovulation represent 33% of the causes of female infertility). In 1998, these therapies had been administrated to approximately two million of USA women. Various Authors have assumed a possible relationship between induction of ovulation and ovarian tumors. Between 1982 and 1997, at least 43 cases of ovarian tumors have been published (among these, there were also 25 cases of epithelial tumors) occurring in women previously treated with ovulation induction. The mean age of patient was 30.3 years, approximately 20 years younger than normal patient population for the same tumors. Among the possible causes of epithelial ovarian tumors, there is the trauma of the ovary surface caused by the continuous repeating of the ovulation phenomenon (incessant ovulation). Gynecologist should be aware of this potential risk for their patients. Multicentric studies should be evaluated in order to establish the risk of ovarian cancer in women treated for infertility problems. A survey of the international literature is made in order to analyse the epidemiological studies and to discuss the relationship between ovulation inducing agents and ovarian tumors.

Adult↗
PubMed2000

Postchemotherapy late recurrence of non metastatic gestational trophoblastic disease following a partiale mole. A case report.

The authors describe a case of a 35-year-old woman who showed elevation of betahCG 13 months after the complete regression of betahCG values following chemotherapy for an incomplete mole. This case outlines the necessity for careful monitoring of betahCG levels in low risk gestational trophoblastic diseases for a period of time longer than one year after achieving the first clinical remission.

Abortion, Spontaneous↗
PubMed2000

[Prostatic phyllodes tumor, a rare entity. Anatamo-clinical and immunohistochemical study of 1 case].

We report the case of a prostatic phyllodes tumor in a 47-year-old man. It measured 6 cm and was composed of a glandular component with leaf-like architecture, lined with two cellular layers, and a moderately cellular stromal component, with no atypia and no mitosis. Basal cells were marked with high-molecular-weight cytokeratin antibody (34BE12) and stromal cells were marked with anti-vimentin and for some of them with CD34 antibodies. Prostatic phyllodes tumor is a rare lesion with uncertain prognosis. Total surgical removal is necessary because malignant transformation to high-grade sarcoma has been reported. In our case the development of the tumor at the posterior side of the prostate, the lack of PSA immunoreactivity and the presence of mucinous glands, sometimes "endocervical-like", could suggest an origin from embryonic mullerian remnants in the prostatic utricle rather than urogenital sinus.

Antigens, CD34↗
PubMed1999

Magnetic fields increase cell survival by inhibiting apoptosis via modulation of Ca2+ influx.

Static magnetic fields with intensities starting from 6 gauss (6x10(-4) tesla, T) were found to decrease in an intensity-dependent fashion, reaching a plateau at 6 x 10(-3) T, the extent of cell death by apoptosis induced by several agents in different human cell systems. This is not due to a change in the mode of cell death (i.e., to necrosis) or to a delay of the process itself; rather, the presence of magnetic fields allows the indefinite survival and replication of the cells hit by apoptogenic agents. The protective effect was found to be mediated by the ability of the fields to enhance Ca2+ influx from the extracellular medium; accordingly, it was limited to those cell systems where Ca2+ influx was shown to have an antiapoptotic effect. Magnetic fields thus might interfere with human health by altering/restoring the equilibrium between cell death and proliferation; indeed, the rescue of damaged cells may be the mechanism explaining why magnetic fields that are not mutagenic per se are often able to increase mutation and tumor frequencies.

Animals↗
PubMed1999

Glutathione depletion causes cytochrome c release even in the absence of cell commitment to apoptosis.

We demonstrate here that the release of mature cytochrome c from mitochondria is a cellular response to the depletion of glutathione, the main intracellular antioxidant, independently from the destiny of the cells, i.e., apoptosis or survival. On the one hand, cytosolic cytochrome c was detected in cells where the inhibition of glutathione synthesis led to glutathione depletion without impairing viability or in tight concomitance with glutathione depletion prior to puromycin-induced apoptosis. Removal of the apoptogenic agent prior to apoptosis, but after glutathione extrusion and cytochrome c release, led to recovery of preapoptotic cells, which resume healthy features, i.e., restoration of normal glutathione levels and disappearance of cytosolic cytochrome c. On the other hand, in an example of apoptosis occurring without glutathione depletion, no translocation of cytochrome c from mitochondria to cytosol was detected. Unlike the other instances of apoptosis, in this case caspase 3 was not activated, thus suggesting the following oxidant-related apoptotic pathway: glutathione depletion, cytochrome c release, and caspase 3 activation. These results show that cytochrome c release is not a terminal event leading cells to apoptosis, but rather is the consequence of a redox disequilibrium that, under some circumstances, may be associated with apoptosis.

Apoptosis↗
PubMed1998

Random amplified polymorphic DNA and amplified ribosomal DNA spacer polymorphism: powerful methods to differentiate Streptococcus thermophilus strains.

Streptococci from different collections and dairy materials were characterized by conventional and molecular methods. After amplification of the 16S-23S rDNA spacer region, all the strains referable to the genus Streptococcus exhibited a single polymerase chain reaction (PCR) product, allowing their differentiation from enterococci. Cleaving this PCR product with Hae III, two different restriction patterns could be observed, allowing Streptococcus salivarius DSM 20560T, Strep. thermophilus NCDO 822 and two strains of Streptococcus spp. to be gathered in one group and all the other strains in another. In order to achieve strain typing, all the cultures were investigated by random amplified polymorphic DNA (RAPD)-PCR analysis employing two selected primers. The results were treated by cluster analysis, appearing significantly consistent with both the taxonomic position and the origin of the strains. Pulsed-field gel electrophoresis (PFGE) of Sma I digests of the genomic DNA from 11 representative strains with decreasing levels of RAPD similarity allowed their diversity to be confirmed, even though RAPD-PCR proved to be less discriminating than PFGE analysis. The results are discussed with reference to the capability of the analytical procedures used to aid both identification and strain typing of streptococci, as well as the taxonomic structure of the species Strep. thermophilus.

Bacterial Typing Techniques↗
PubMed1998

Effect of leavening microflora on pizza dough properties.

Fourteen different starter cultures containing one strain of Saccharomyces cerevisiae with and without individual or combinations of lactic acid bacteria (Lactobacillus plantarum, Lact. sanfrancisco, Enterococcus faecium, Leuconostoc mesenteroides) were employed to investigate the role of leavening microflora on the properties of pizza doughs. Microbiological, chemical and physical characteristics of doughs prepared with the same flour and under the same processing conditions were determined. Leavening times and acidification properties depended on the microbial association used. The proportions of lactic and acetic acid produced by lactic acid bacteria were consistent with the metabolic properties of the strains employed. The bacteria/yeast ratios arising from microbial counts at the end of the leavening process were always lower in comparison to sour- or bread-doughs. The size of the yeast population did not change much, while bacteria showed from one to four duplications. Rheologically, the fermented doughs could only be significantly distinguished from the control dough with regard to the elastic modulus. Principal Component Analysis was applied to the acidimetric data. The scattergram of the two principal components effectively discriminated 13 of the 14 pizza dough types.

Acetic Acid↗
PubMed1998

Fluconazole susceptibility and strain variation of Candida albicans isolates from HIV-infected patients with oropharyngeal candidosis.

Over a 16 month period we conducted a prospective study in a cohort of 45 HIV-positive patients to detect the development of resistance to fluconazole and to analyse the epidemiology of oropharyngeal candidosis (OPC). Each episode was treated with fluconazole 100 mg/day po for 10 days. All yeast isolates were tested for their in-vitro susceptibility to fluconazole. Multiple strains of Candida albicans simultaneously isolated from a given patient were typed by electrophoretic karyotyping. Overall, 106 episodes of OPC were diagnosed among the 45 patients: 18/45 patients (40%) had only one episode, 11/45 (24%) had two episodes, and the remaining 16/45 (36%) had three or more episodes (range 3-7). Cure (complete resolution of signs and symptoms and negative post-treatment cultures) and improvement (complete resolution of signs and symptoms but positive post-treatment cultures) were observed in 30/106 (28%) and 69/106 (65%) episodes of OPC, respectively. Failure (absence of improvement or exacerbation of signs and symptoms) was observed in seven episodes (7%) from four patients. In two of these four patients a significant and progressive increase in fluconazole MICs was observed: from 0.25 to 16 mg/L in one patient, and from < or = 0.125 to 32 mg/L in the second one. Tests on multiple colonies from individual isolation plates showed that it was not unusual to obtain different fluconazole MICs, indicating that, in order to avoid misleading results, one should perform in-vitro susceptibility testing by using a multiple colony inoculum rather than an inoculum made from a single colony. A total of 213 strains of C. albicans isolated from seven patients who suffered from four or more episodes of OPC through the course of the study were typed by electrophoretic karyotyping. Five individuals (71%) were infected with yeasts with only one DNA type, while the other two patients showed the presence of two or three different DNA types. The simultaneous presence of multiple types was found only in one of the seven subjects. Our data confirm the efficacy of fluconazole 100 mg/day for the treatment of OPC in HIV patients. Isolation of fluconazole-resistant strains of C. albicans with this regimen is rare. The vast majority of HIV patients are infected with a unique strain of C. albicans throughout each episode of infection. A minority of patients, however, can harbour strains of C. albicans with variable patterns of fluconazole susceptibility simultaneously.

AIDS-Related Opportunistic Infections↗
PubMed1998

Rescue of cells from apoptosis by inhibition of active GSH extrusion.

Cells induced to apoptosis extrude glutathione in the reduced form concomitantly with (U937 cells) or before (HepG2 cells) the development of apoptosis, much earlier than plasma membrane leakage. Two specific inhibitors of carrier-mediated GSH extrusion, methionine or cystathionine, are able to decrease apoptotic GSH efflux across the intact plasma membrane, demonstrating that in these cell systems GSH extrusion occurs via a specific mechanism. While decreasing GSH efflux, cystathionine or methionine also decrease the extent of apoptosis. They fail to exert anti-apoptotic activity in cells previously deprived of GSH, indicating that the target of the protection is indeed GSH efflux. The cells rescued by methionine or cystathionine remained viable after removal of the apoptogenic inducers and were even able to replicate. This shows that a real rescue to perfect viability and not just a delay of apoptosis is achieved by forcing GSH to stay within the cells during apoptogenic treatment. All this evidence indicates that extrusion of reduced glutathione precedes and is responsible for the irreversible morphofunctional changes of apoptosis, probably by altering the intracellular redox state without intervention of reactive oxygen species, thus giving a rationale for the development of redox-dependent apoptosis under anaerobic conditions.

Apoptosis↗
PubMed1998

Pregnancy-associated breast cancer.

Pregnancy-associated breast cancer, which is defined as all breast cancer diagnosed during pregnancy or within the following year, is a relatively rare finding. Due to the particular difficulties in the diagnosis of breast cancer during this period, pregnant women tend to present more advanced disease at diagnosis. Four cases of pregnancy-associated breast cancer referred to our Institute are described as a contribution to the knowledge of this disease.

Adult↗
PubMed1997

Partial recovery of in vivo function by improved incubation conditions of isolated renal proximal tubule. I. Change of amiloride-inhibitable K+ conductance.

Isolated microperfused rabbit renal proximal tubule S2 segments, if incubated in conventional substrate containing HCO3- Ringer solution, exhibit lower cell membrane potentials (Vb) and elevated intracellular Na+ concentrations ([Na]i) compared to rat tubules in vivo. Assuming that these and other differences reflect insufficient metabolic and/or hormonal stimulation of the cells, we have used microelectrode techniques to test whether improving substrate supply and applying norepinephrine (NE, to compensate for the missing nerve supply) reverts Vb and [Na]i to values observed in vivo. Application of D-glucose (5.5 mmol/l) and additional application of pyruvate, lactate, or L-alanine (each 10 mmol/l), or bathing the tubules in Dulbecco's modified Eagle's tissue culture medium (DMEM) significantly increased Vb and, whenever tested, reduced [Na]i as compared to substrate-free or D-glucose-containing control solution and these effects could be prevented - as tested in the case of pyruvate - by inhibition of the Na/K pump with ouabain. However, high concentrations of acetate, beta-hydroxybutyrate, or L-glutamine had no significant effect. The largest effect was obtained with joint application of DMEM and NE (10 micromol/l) which increased Vb from -42.8 +/- 1.3 mV (SEM) to -55.3 +/- 2.5 mV (n = 11). Interestingly we noticed that under the latter conditions the Vb response to bath application of 1 mmol/l amiloride virtually disappeared, i.e. it changed from a depolarization of +14.6 +/- 1.4 mV (in D-glucose Ringer solution) to +0.6 +/- 0.7 mV (in DMEM plus NE) (n = 8), with some tubules showing even a small hyperpolarization. The latter implies partial restoration of the in vivo behaviour, since in experiments on rat proximal tubules in vivo amiloride regularly hyperpolarized the cells (by -3.4 +/- 0.76 mV, n = 5). Obviously under conventional in vitro conditions an amiloride-inhibitable K+ conductance is activated which is inactive in vivo and also inactivates under improved conditions in vitro. In agreement with observations reported in the subsequent publication our results demonstrate that isolated proximal tubules undergo functional alterations which may be largely prevented by improved metabolic and stimulatory incubation conditions.

Amiloride↗
PubMed1997

Survey of the deliveries of immigrant women from developing countries in the 2nd Institute of Gynaecology and Obstetrics, University of Rome, 'La Sapienza', Italy.

Five hundred and forty-four immigrant women, admitted from 1983 to 1993 to the 2nd Institute of Obstetrics and Gynaecology of Rome University, were enrolled in the study. Africa and East Europe were the most common places of birth. Seventy-five per cent of women gave birth spontaneously, and a caesarean section was performed in 22.2%. The frequency of spontaneous delivery and caesarean section was about the same among Italian and immigrant women.

Journal Article↗
PubMed1997

Characterization of strains of Leuconostoc mesenteroides by analysis of soluble whole-cell protein pattern, DNA fingerprinting and restriction of ribosomal DNA.

Of 215 leuconostocs isolated from field grass, natural whey cultures and water-buffalo milk, 178 were identified as Leuconostoc mesenteroides ssp. mesenteroides while 37 strains could not be identified. Biochemical characterization allowed seven groups to be defined. Representative strains of each group and different habitat and nine reference strains were selected for further analyses. Protein profiles appeared suitable for species discrimination, but did not differentiate between the three subspecies of Leuc. mesenteroides. The technique also showed some differences among equivocal strains. DNA fingerprinting for most strains of Leuc. mesenteroides ssp. mesenteroides examined showed a different restriction pattern from that of the type strain. Ribotyping was not useful for discriminating species and subspecies of the genus Leuconostoc: Leuc. mesenteroides ssp. mesenteroides and ssp. dextranicum showed the same ribopattern as Leuc. lactis while Leuc. mesenteroides ssp. cremoris exhibited a pattern distinct from all the other species examined. On the basis of ARDRA-PCR, two main groups could be distinguished: the larger group included Leuc. mesenteroides, Leuc. lactis, Leuc. pseudomesenteroides and some unidentifiable strains; the second one included Leuc. citreum, Leuc. fallax, Weissella paramesenteroides and some unidentified strains.

Animals↗
PubMed1996

Protease involvement in fodrin cleavage and phosphatidylserine exposure in apoptosis.

A detailed kinetic analysis of three extranuclear end points of apoptosis, phosphatidylserine exposure, alpha-fodrin degradation, and plasma membrane blebbing, was performed and compared with nuclear fragmentation and the activation of the interleukin-1beta-converting enzyme (ICE)-like proteases in Jurkat T lymphocytes stimulated by anti-Fas monoclonal antibody (anti-Fas mAb) and in monocytic U937 cells stimulated by tumor necrosis factor (TNF) and cycloheximide. Phosphatidylserine exposure was quantitated by plasma clotting time, as well as annexin V-fluorescein isothiocyanate binding, and the ICE-like protease activity was examined by the cleavage of a specific fluorogenic peptide substrate Ac-Asp-Glu-Val-Asp-amino-4-methylcoumarin. VAD-chloromethylketone (VAD-cmk), an inhibitor of ICE-like proteases, effectively inhibited ICE-like activity in both cell types studied, whereas the calpain inhibitor calpeptin was ineffective. VAD-cmk also effectively inhibited all three extranuclear events, as well as nuclear fragmentation, in Jurkat cells stimulated by anti-Fas monoclonal antibody, indicating that ICE-like proteases play an important role in the regulation of this apoptotic system. Calpain inhibitors were ineffective in this system. TNF-induced extranuclear and nuclear changes in U937 cells were inhibited by calpeptin but were not as effectively inhibited by VAD-cmk as in Jurkat cells. This suggests that ICE-like enzymes predominate in anti-Fas monoclonal antibody-stimulated Jurkat cells, whereas proteases affected by calpain inhibitors as well as the ICE-like enzymes are involved in the signaling of apoptotic events in TNF-induced U937 cells. Importantly, the two apoptotic systems seem to be regulated by different proteases.

Antibodies, Monoclonal↗
PubMed1996

Presence of non-functional nisin genes in Lactococcus lactis subsp. lactis isolated from natural starters.

Sixty-four lactococcal strains isolated from natural whey starters were screened for the presence of the nisin structural gene by polymerase chain reaction. Seven of them showed a specific PCR product of 320 bp; only two produced antagonistic activity and were resistant to nisin. Southern blots of SmaI-digested DNA from PCR-positive strains hybridized with a nisA probe displayed a location of the gene on different SmaI fragments. Among PCR-positive strains, nisin producers showed specific transcript after reverse transcriptase-PCR, as well as some non-nisin-producing strains. The RT-PCR product could not be shown in one non-nisin-producing PCR-positive strain.

Animals↗