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Biomedical subjects

F Gandolfi

Publications and source records attributed to F Gandolfi.

At least 19 recordsLinked to original sources
PubMed1992

Uptake of exogenous DNA by mammalian spermatozoa: specific localization of DNA on sperm heads.

When mouse spermatozoa were briefly exposed in culture to radioactively labelled DNA (pSV2CAT plasmid), radioactivity could be detected by high-resolution autoradiography on the surface and within the nucleus of the spermatozoa. Spermatozoa from other mammalian species (boar, bull, man) could also bind foreign DNA. With the exclusion of human spermatozoa, which in most experiments showed very low labelling values, labelling percentages (evaluated by light microscope autoradiography) ranged between 39 and 78%. In all four species the DNA-binding ability was mainly confined to a specific region of the sperm head (equatorial segment and postacrosomal region), and the sperm-DNA association kinetics were rapid (maximum values were reached within 20-40 min). The data also indicate that factor(s) in seminal plasma might protect spermatozoa from accidental transfection by foreign DNA that may be present in the genital tracts from bacterial or viral sources.

Animals↗
PubMed1991

Oviduct ampullary epithelium contributes a glycoprotein to the zona pellucida, perivitelline space and blastomeres membrane of sheep embryos.

Previous studies have identified a glycoprotein (sOP 92) that is secreted by sheep oviductal epithelium and subsequently becomes associated with developing embryos. The objective of this study was to more definitively demonstrate the localization of this protein in the oviductal epithelium of cycling ewes and in the embryos (developmental stage ranging between 1 and 8 cells) by using the light and electron microscopic immuno-gold techniques. In the oviduct, sOP 92 was present only in nonciliated cells of the ampulla but not in the isthmus. No major differences in signal intensity, in its organ or intracellular distribution were observed between the postovulatory and the luteal phase of the cycle. At the embryonic level, sOP 92 uniformly covered the surface of the zona pellucida and permeated its width. Moreover, the protein was present in the perivitelline space and on the blastomeres membrane but not in the cytoplasm or in the nucleus. These observations suggest that a marked regional difference in sheep oviduct secretions exists and confirm that there is a close association of these secretions with the developing embryos.

Animals↗
PubMed1990

[Neoplasms intrinsic to the cheek. Diagnostic and surgical approach].

In the light of nineteen personal observations during the past ten years, the Authors remember at first the anatomy of the cheek then the diagnostic approach and the surgery management of this complex region. They specify the variety of cheek space lesions and the possibility of rare or malignant masses involving the cheek. They emphasize the aesthetic results with the different surgery approaches.

Cheek↗
PubMed1989

[Neoplasms of the parotid space. Therapeutic guides].

The Authors report about 161 neoplasms of the parotid space observed in the ten-year period since 1977 to 1987. With the exception of carcinomas and mucoepidermoid tumors, always to be treated by total parotidectomy, for the remaining pathology of the gland either neoplastic or not neoplastic as well as the extra salivary tissues diseases, the Authors suggest a conservative surgical treatment, in respect of the facial nerves and of the salivary tissue not directly involved.

Adolescent↗
PubMed1989

Characterization of proteins secreted by sheep oviduct epithelial cells and their function in embryonic development.

The role in early development of proteins secreted by oviduct epithelial cells has been investigated. Secreted proteins devoid of serum contamination have been produced by the surgical removal and immediate incubation of oviduct cells in [35S]methionine-containing medium. After electrophoretic separation, secreted polypeptides could be divided into those that were secreted uniformly throughout the oestrous cycle and a second class that showed a cyclical pattern of secretion. The first class of proteins represented a small proportion of total output whilst the predominant second class was composed mainly of polypeptides of Mr 92 and 46 x 10(3), respectively. Both of these polypeptide species, referred to as sheep oviduct proteins 92 and 46 (SOP 92, SOP 46), are detected only during the first 4 to 5 days after oestrus when the embryos are located in the oviduct. Oviduct cells collected at oestrus and maintained thereafter in culture secrete the same pattern of proteins and follow the same time course as their counterparts in vivo. The interaction between the oviduct proteins and the developing embryo was studied firstly by determining whether any of the secreted proteins bound to the zona pellucida. The results of iodination studies showed that two polypeptides of Mr 92 and 46 x 10(3), respectively, were bound to the zona pellucida of eggs removed from the oviduct but were absent from eggs that had not had contact with the oviduct epithelium. That these newly acquired proteins represent SOP 92 and 46 is suggested by their electrophoretic mobility and their ability to bind to the zona of follicular eggs when added in vitro and by the fact that they both disappear from the zonae of embryos after exit from the oviduct. The collection of unlabelled secreted proteins enabled us to produce a monoclonal antibody, which was used in the second series of experiments on oviduct-embryo interactions. The results confirmed that SOP 92 binds to the zona pellucida and moreover showed that this protein crosses the zona and becomes associated with the individual blastomeres of the developing embryo. These findings provide evidence that the mammalian oviduct probably plays a direct role in supporting embryonic development through specific polypeptides produced by its epithelium.

Animals↗
PubMed1988

Ram-specific effects on in-vitro fertilization and cleavage of sheep oocytes matured in vitro.

The present experiments were designed to identify possible male-specific effects on early embryonic development in vitro: Sheep oocytes were matured in vitro for 24-26 h and then fertilized in vitro using equal numbers of viable spermatozoa from 1 of 6 Clun Forest rams. At 15-18 h after insemination, oocytes were either fixed and examined for fertilization and polyspermy or further cultured in modified M 199 medium for 3 days in an oviduct epithelial co-culture system. There were significant differences in 5 separate trials between the rams with respect to the rate of fertilization, degree of polyspermy and cleavage rate after monospermic fertilization. The mean rate of fertilization varied from 89% in Ram B to 43% in Ram C while the percentage of polyspermic eggs varied from 5 to 34%. Both the absolute number of embryos cleaving to the 16-cell stage and the calculated percentage of monospermic eggs reaching the 16-cell stage differed markedly between groups of eggs fertilized by different rams. The results indicate that the development of sheep eggs in vitro is differentially affected by the ram from which the spermatozoa are collected.

Animals↗
PubMed1988

Control of protein synthesis during early cleavage of sheep embryos.

Sheep embryos, radiolabelled with [35S]methionine, were studied during the first four cell cycles after fertilization to determine the stage at which the regulation of protein synthesis switches from the direction by maternal mRNA to mRNA transcribed by the embryonic genome. Total protein synthesis was consistently high during the first 2 cleavage divisions, dropped by 95% in the 3rd cell cycle, remained low in the 4th and increased again in the 5th cycle. A consistent pattern of proteins was synthesized during the first 3 cell cycles after fertilization followed by major changes in subsequent cycles. The inhibition of transcription by alpha-amanitin, an inhibitor of polymerase II, did not affect cleavage or protein synthesis during the first 3 cell cycles but blocked cleavage and protein synthesis thereafter. The results indicate that the full activation of transcription in sheep embryos occurs in the 4th cell cycle.

Amanitins↗
PubMed1987

Stimulation of early embryonic development in the sheep by co-culture with oviduct epithelial cells.

To examine the effects of somatic cell support on the cleavage and viability of fertilized sheep eggs, 434 pronucleate eggs were co-cultured for 3 or 6 days on oviduct cells or fibroblasts and 77 eggs were cultured in medium alone. During the first 3 days in culture 95% of the single-celled eggs cleaved regularly to non-compacted morulae on either of the feeder-layers but only 13% underwent similar regular cleavage in medium alone. Despite the identical cleavage rates in the co-culture groups, only 33% of embryos grown on fibroblasts as compared with 80% of embryos grown on oviduct cells were fully viable as judged by their ability to develop normally after transfer to recipient animals. The viability of embryos in the oviduct group was equal to that obtained after the direct transfer of morulae from donor to recipient sheep. After 6 days in culture 42% of embryos co-cultured with oviduct cells developed into expanded blastocysts as compared with only 4.5% cultured on fibroblasts. In both co-culture groups virtually all the remaining embryos blocked during the 4th cleavage. When transferred, 30% of blastocysts grown from the pronucleate stage on oviduct cells were viable. We conclude that: (1) during the first 3 days after fertilization cleavage will progress at a normal rate on different feeder-layers but oviduct cells appear to be required for the acquisition of full embryonic viability.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Endogenous opioid peptides in uterine fluid.

The present study demonstrates the presence of the endogenous opioid peptides beta-endorphin (beta-EP) and methionine-enkephalin (MET-ENK), in the uterine fluid of fertile women and normally cycling and superovulated cows. The two peptides are undetectable in the uterine fluid of untreated postmenopausal women, whereas they are present following estrogen-progesterone treatment. Immunoreactive (IR) MET-ENK concentrations were higher in the secretory than in the proliferative phase of the menstrual cycle. IR beta-EP and IR MET-ENK are present also in the follicular, oviductal, and uterine fluid of cows, and in the uterine fluid, concentrations of IR MET-ENK are higher in the superovulated than in the control animals. Because opioids play important roles on endocrine and immune functions, the present data support the potential physiologic role of endometrial secretions.

Adult↗
PubMed1986

The effect of extracellular matrix modifications on UDP-glucose dehydrogenase activity in cultured human skin fibroblasts.

The effect of modifications of the extracellular matrix on the biosynthesis of glycosaminoglycans was investigated in human skin fibroblast cultures by studying UDPGDH activity in order to evaluate: a), the histoenzymological and biochemical modifications induced by chondroitinase ABC treatment (new experimental conditions were developed in order to obtain minimum cell damage); b), the reversibility of these modifications; c), the effect of growing the cells in the presence of chondroitinsulfate; d), the specificity of the modifications induced. The results demonstrated that our experimental conditions specifically affected intracellular UDPGDH activity. Chondroitinase ABC treatment induced a reversible increase of UDP-glucuronic acid synthesis. On the contrary, the presence of chondroitinsulfate in the growth medium completely inhibited UDPGDH activity.

Carbohydrate Dehydrogenases↗
PubMedDate not supplied

[Prevalence of Streptococcus mutans in a school group].

In the present study, S. mutans colony morphotypes has been investigated in salivary specimens obtained from 67 schoolchildren. Prevalence of these bacteria has been matched with DMFS in order to obtain information on cariogenicity of single morphotypes. Our data seems to suggest a correlation between total count of S. mutans colonies and caries experience, with major evidence for two colony morphotypes.

Adolescent↗