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S Dolci

Publications and source records attributed to S Dolci.

45 records · Page 3Linked to original sources
PubMed1989

Fetal germ cells establish cell coupling with follicle cells in vitro.

In the present paper we investigate whether the adhesion that occurs in vitro between mouse fetal germ cells and follicle cells is accompanied by the establishment of cell coupling between the two cell types. The possible coupling between germ cells that spontaneously aggregate in culture has also been monitored. When germ cells, isolated from the gonads of 12.5-13.5-day-post coitum embryos, were loaded with 6-carboxyfluorescein diacetate and seeded onto follicle cell monolayers dye was transferred from the germ cells to the adjacent somatic cells within 2-3 h of culture. No dye transfer was observed when germ cells were seeded on fibroblast monolayers or between members of homotypic germ cell aggregates. These results indicate that, following cell to cell adhesion, fetal germ cells are able to establish heterocellular gap junctions with somatic cells of gonadal origin in culture.

Animals↗
PubMed1987

Involvement of thiol-disulfide groups in the sensitivity of fully grown mouse oocytes to calcium-free medium.

The lethality caused by calcium-free medium (CFM) to fully grown mouse oocytes significantly decreases if a disulfide reducing agent (dithiothreitol, reduced glutathione, or L-cysteine) is added to the medium. In this condition, most of the surviving oocytes do not spontaneously resume meiosis. We also show that the sulfhydryl content of fully grown oocytes, estimated by monobromobimane labeling, rapidly decreases during culture in CFM. The hypothesis is discussed that lethality of oocytes cultured in CFM may be a consequence of an alteration of thiol-disulfide balance.

Animals↗
PubMed1986

Putative second messengers affect cell coupling in the seminiferous tubules.

Junctional transfer of ions in monolayer primary cultures of Sertoli cells and in intact seminiferous tubules from 20 day-old rats has been investigated by using electrophysiological techniques. The electrotonic coupling of both intact tubule and monolayer culture was inhibited by the presence of dibutyryl cyclic AMP (10(-4) M) in the medium. In contrast, 1-oleoyl-2-acetylglycerol (10(-5) M) and 12-O-tetradecanoyl-phorbol-13-acetate (10(-7) M) decreased the junctional resistivity and increased the extent of the coupling in immature tubules. The significance of this modulation of the cell coupling in the seminiferous epithelium is discussed.

Animals↗
PubMed1985

Cell-to-cell communication in cultured Sertoli cells.

Junctional transfer of ions in monolayer primary cultures of Sertoli cells has been studied by using conventional techniques. Cells were extensively electrically coupled. Membrane voltage displacements caused by the injected current pulses were measured at variable interelectrode distance. Data analyses were based on a thin-sheet model for current flow (Jongsma and van Rijn, 1972) and yielded a generalized space constant of 248 microns and an internal resistivity of 1.7 kOhm.cm in standard medium. Electrical coupling was inhibited by A23187 Ca2+ ionophore (5 microM).

Animals↗
PubMed1985

gamma-Amino butyric-N-acid sensitivity of mouse and human oocytes.

gamma-Aminobutyric acid (GABA)-sensitivity was studied in mouse and human oocytes using electrophysiological techniques. Isolated mouse oocytes at the germinal vesicle (GV) or metaphase II stage, and human oocytes at the GV stage or following resumption of meiosis in culture, were sensitive to GABA. The transmitter usually hyperpolarized the membrane, with a concomitant decrease followed by an increase in membrane conductance, at threshold concentrations as low as 10(-10) M. GABA response was not evoked in Cl-free medium. Bicuculline (10(-5)-10(-6) M) reversibly blocked GABA (10(-9)-10(-4) M) responses. In contrast mouse fertilized eggs were insensitive to GABA at concentrations of 10(-5) M or lower. A possible biological role of the neurotransmitter GABA is discussed.

Animals↗
PubMed1981

Fluorescence-determined preferential binding of quinacrine to DNA.

Quinacrine complexes with native DNA (Calf thymus, Micrococcus lysodeikticus, Escherichia coli, Bacillus subtilis, and Colstridium perfringens) and synthetic polynucleotides (poly(dA) . poly(dT), poly[d(A-T)] . poly[d(A-T)], poly(dG) . poly(dC) and poly[d(G-C)] . poly[d(G-C)]) has been investigated in solution at 0.1 M NaCl, 0.05 M Tris HCl, 0.001 M EDTA, pH 7.5, at 20 degrees C. Fluorescence excitation spectra of complexes with dye concentration D = 5-30 microM and DNA phosphate concentration P = 400 microM have been examined from 300 to 500 nm, while collecting the emission above 520 nm. The amounts of free and bound quinacrine in the dye-DNA complexes have been determined by means of equilibrium dialysis experiments. Different affinities have been found for the various DNAs and their values have been examined with a model that assumes that the binding constants associated with alternating purine and pyrimidine sequences are larger than those relative to nonalternating ones. Among the alternating nearest neighbor base sequences, the Pyr(3'-5')Pur sequences, i.e., C-G, T-G, C-A and T-A seem to bind quinacrine stronger than the remaining sequences. In particular the three sites, where a G . C base pair is involved, are found to display higher affinities. Good agreement is found with recent calculations on the energetics of intercalation sites in DNA. The analysis of the equilibrium shows also that the strength of the excitation spectrum of bound dye depends strongly upon the ratio of bound quinacrine to DNA. This effect can be attributed to dye-dye energy transfer along DNA.

Animals↗
PubMedDate not supplied

ATP-content and kinetics of acrosome reaction in human spermatozoa: influence of various culture media and incubation time.

The ATP content and the kinetics of acrosome reaction of isolated human spermatozoa were investigated during an in vitro culture period of 3 hours in 3 serum-enriched media commonly adopted in IVF and GIFT procedures (Earle solution, Ham F10 and Menezo B2). The ATP concentration in spermatozoa did not change between 1 and 3 hr of incubation and no differences were seen using the three media under investigation. The percentage of acrosome reactions significantly increased during culture, to a similar extent in the three media. The results suggest that each of the three media is equally well suitable for human sperm culture in preparation of IVF and GIFT procedures.

Acrosome↗
PubMedDate not supplied

Doxorubicin followed by docetaxel versus docetaxel followed by doxorubicin in the adjuvant treatment of node positive breast cancer: results of a feasibility study.

BACKGROUND: Doxorubicin (A) and Docetaxel (T) are amongst the most active agents in breast cancer treatment. The impact of drug sequencing is an issue still under evaluation. OBJECTIVE: To evaluate the feasibility and tolerability of two A and T-based sequential regimens, in which the sequence of drug administration was reversed. METHODS: The study included patients pts aged < or = 70 years, with operable node positive breast cancer. Two consecutive groups of patients received one of the following regimens: 1) Sequential A-->T-->CMF: Doxorubicin 75 mg/m2, i.v., day 1, q3wks x 3 cycles, followed by Docetaxel 100 mg/m2, i.v., day 1, q3wks x 3 cycles, followed by i.v. CMF days 1 and 8 q4wks x 3 cycles. 2) Sequential T-->A-->CMF: same doses for Doxorubicin and Docetaxel but reverse sequence of administration, followed by oral CMF (CPA 100 mg/m2, oral, days 1-14 + MTX 40 mg/m2, i.v., days 1 and 8 + 5FU 600 mg/m2, i.v., days 1 and 8, q4wks). An analysis of treatment administration and toxicity was performed for the first six cycles of CT, in the two treatment groups. RESULTS: Group 1 with 20 patients and group 2 with 14 patients were balanced in terms of patient and tumour characteristics. There was one early treatment discontinuation in each group due to toxicity (one allergic and one skin reaction to docetaxel). Median relative dose intensity was 100% for both drugs in both groups. The most relevant side effects were (overall incidence, group 1 vs group 2): Myalgia: 45% vs 72%; Arthralgia: 15% vs 57%; Skin: 35% vs 57%; Neurosensory: 55% vs 64%; Stomatitis 65% vs 36%; conjunctivitis 25% vs 57%; Neutropenic Fever 20% vs 21% and Fatigue 80% vs 93%. Grade 3/4 adverse events' rate was low in the two groups. CONCLUSIONS: 1) Both sequences were estimated feasible due to the optimal treatment administration and limited incidence of G3-G4 side effects. 2) The concomitant use of lenograstin might partially explain the reported incidence of myalgia and arthralgia. 3) No conclusion can be drawn on the most tolerable regimen due to the limited number of patients.

Adult↗