PubMed Health⌕ Search

Biomedical subjects

T Renieri

Publications and source records attributed to T Renieri.

At least 19 recordsLinked to original sources
PubMed2003

Effects of diadenosine polyphosphates and seminal fluid vesicles on rabbit sperm cells.

Membrane vesicles were isolated from rabbit seminal plasma. Electron microscopy analyses showed the presence of numerous small, round vesicles with a diameter of about 70 nm. Determination of enzyme activities was carried out by high performance liquid chromatography and showed that the vesicles can degrade the diadenosine polyphosphates (ApnA), Ap3A and Ap4A and ATP and ADP, but not AMP. Studies of the degradation of diadenosine compounds by the vesicles present in seminal fluid showed an increasing production of AMP as the by-product and a time-dependent generation of dephosphorylated products consistent with the presence of ecto-ATP diphosphophosphatase (ecto-apyrase). In the presence of rabbit spermatozoa, AMP did not accumulate because 5'nucleotidase and adenosine deaminase, present at the surface of sperm cells, transformed AMP into adenosine and inosine. The effects of seminal fluid vesicles and diadenosine compounds on the acquisition of fertilizing capacity by rabbit spermatozoa were evaluated by Pisum sativum agglutinin fluorescein isothiocyanate conjugated staining. The results obtained with uncapacitated spermatozoa showed that the capacitating effector BSA could be substituted efficiently by the addition of diadenosine compounds and vesicles previously incubated for 2 h to the capacitative medium. Under these experimental conditions, the spontaneous acrosome reaction rate was not increased. Capacitated rabbit spermatozoa did not undergo acrosome reaction when l-alpha-lysophosphatidylcholine was substituted by diadenosine compounds previously incubated with vesicles. In conclusion, this study has shown that rabbit seminal fluid vesicles can degrade diadenosine compounds to AMP and that the addition of the vesicles and diadenosine compounds to uncapacitated rabbit spermatozoa favours the acquisition of the fertilizing capacity.

5'-Nucleotidase↗
PubMed2002

Helicobacter pylori infection and infertility.

OBJECTIVE: To determine (1) the prevalence of Helicobacter pylori infection in male and female patients with reproductive disorders and controls; (2) the presence of anti-H. pylori antibodies in samples of follicular fluid, vaginal secretions and sperm; and (3) the existence of a structural homology between a major spermatozoa protein, tubulin, and H. pylori proteins. PATIENTS AND METHODS: Serum samples from 167 patients with infertility and 837 age- and gender-matched controls (blood donors) were examined by enzyme-linked immunosorbent assay (ELISA) and Western blotting to determine the seropositivity for H. pylori infection. The presence of anti-H. pylori antibodies in samples of follicular fluid, vaginal secretions and sperm was determined using the same techniques. The possible cross-reactivity with spermatozoa of anti-H. pylori hyperimmune sera and human antibodies was studied by immunofluorescence. The N-acid homology of human tubulin with the principal H. pylori proteins was assayed by the WU-blastp program available on the Internet. RESULTS: The prevalence of infection was significantly higher in patients than controls (49.1% v. 33.5%, P < 0.001). Follicular fluids from infected patients contained specific antibodies in all cases, sperm samples in about 50% of cases, and vaginal secretions in a minority of cases. Sera to H. pylori whole antigens and VacA reacted with the tails and the pericentriolar area of human spermatozoa (which are rich in tubulin); sera to urease and heat-shock protein (Hsp) did not. Follicular fluids with anti-H. pylori antibodies immune reacted with spermatozoa. A linear homology was found between beta-tubulin and three H. pylori proteins, flagellin, VacA and CagA. CONCLUSIONS: H. pylori infection may increase the risk of developing reproductive disorders or worsen the clinical expression of this syndrome.

Adolescent↗
PubMed2002

Culture and co-culture of DU145 prostate carcinoma, osteoblasts and HT-29 colon carcinoma cells on a fabricated type III collagen matrix.

DU145 prostate carcinoma cells cultured on type III collagen possessed a highly migratory potential which was twice as much as HT-29 colon carcinoma cells. Prior to attachment to collagen, DU145 cells were highly reactive for fibronectin and after attachment clear zones between cells and collagen suggested protease activity. HT-29 cells attached to type III collagen forming dome-like polyps, however, tight and/or gap junctions were not observed. hFob osteoblasts were co-cultured with DU145 to establish a prostate cancer-collagen matrix barrier-bone cell metastasis model. Osteoblasts maintained their differentiated osteoblastic characteristics on one side of the collagen barrier, demonstrating high alkaline phosphatase, osteocalcin and insulin growth factor (IGF) activities. hFob cell growth was prominent adjacent to demineralized bone matrix particles (BMPs) embedded in type III collagen. The collagen matrix was deteriorated on the DU145 side of the collagen barrier. The DU145-collagen III-hFob model will allow an evaluation of the influence of the matrix on prostate cancer-bone cell interaction and regulation by growth factors.

Alkaline Phosphatase↗
PubMed1991

Studies on varicocele. 1. Submicroscopical and endocrinological features.

In this study we have selected a group of patients affected by a more or less severe condition of varicocele. After the evaluation of spermatogenesis and sperm function by electron microscopy we have demonstrated that the sperm malformations are mostly due to immaturity. Subsequently we have observed low FSH levels in the blood, concomitant with inhibin high contents, and we have studied Sertoli cells at submicroscopical level. In conclusion we suggest the following mode of action of varicocele in endocrinologically and spermatologically altered patients: varicocele----Sertoli cells----increased inhibin----hypophysis----decreased FSH----decreased testosterone----aberrant spermatogenesis----immature spermatozoa. The research will continue.

Adult↗
PubMed1991

HIV particles detected in spermatozoa of patients with AIDS.

In this paper the Authors describe the presence of HIV particles on and in mature spermatozoa either ejaculated by AIDS patients or incubated in vitro with HIV. Both kinds of spermatozoa have particles localized around the sperm organelles. In the first case, the nucleoid of the virus can be enveloped by a membrane-like coat or be devoid of it and form buddings in the plasma membrane. In the in vitro infected spermatozoa, only membrane enveloped nucleoids are present, and no process of budding can be found. The Authors conclude considering that the spermatozoa of the AIDS patients can be penetrated by the virus particles in different moments of their life, and show the HIV particles in different stages of their cycle: some of them have freshly penetrated the sperm, and are still contained in a membrane-like coat, others are replicated and are budding through the sperm plasma membrane. On the contrary, in vitro infected spermatozoa have only freshly penetrated virus particles, and lack buddings and membrane-free nucleoids. The presence of the HIV virus in spermatozoa is substantiated by labelling with monoclonal or polyclonal anti-HIV antibodies.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Crater defect in human spermatozoa.

This report describes the "crater defect" in human spermatozoa, a malformation that consists of a nuclear and acrosomal invagination present in 100% of the cells, whereas tail structure and motility are fairly normal. The defect occurs during spermiogenesis. A possible concomitance with abnormalities in the microtubular apparatus involved in the sperm molding is discussed.

Adult↗
PubMed1989

Morphogenesis of the decapitated and decaudated sperm defect in two brothers.

The "decapitated sperm" defect, found in both of two sterile brothers, may be assumed to have a genetic origin. The present material suggests that the term "decapitated spermatozoa" is not exact, because detached heads and tails were found in the brothers' ejaculate that could be regarded as "decapitated tails" and "decaudated heads." The present report describes frequent, more or less advanced stages of detachment. Both heads and tails showed a normal structure in which only the postnuclear region was deficient, lacking basal plate and implantation fossa. A break at a different level of the midpiece, and therefore three kinds of separation, were observed. The defect, according to the present research, must originate in the testicular region, whereas the detachment occurs in the epididymis.

Adult↗
PubMed1989

Localization of acrosomal enzymes in Arthropoda, Echinodermata and Vertebrata.

The presence and localization of acrosin and hyaluronidase have been detected by immunocytochemistry in animals belonging to different phyla and characterized by the different structure of the acrosomal complex. Acrosin is widely distributed from Insecta to Echinodermata and Vertebrata; hyaluronidase has a similar diffusion, but seems to be absent from an Insect and from Echinodermata. The presence of extraacrosomal layer and perforatorium seems not to be related to that of the two enzymes, that are absent from Teleost species devoid of acrosome or having only a pseudoacrosome.

Acrosin↗
PubMed1988

Polarized site of sperm entrance in the egg of a freshwater bivalve, Unio elongatulus.

We studied the organization of the egg of a freshwater bivalve, Unio elongatulus. This egg is markedly polarized. At the vegetal pole there is a crater which constitutes the point of attachment of the growing oocyte to the ovarian wall. This has previously been interpreted as a micropyle. We show that the sperm does not enter the egg through the crater but in a differentiated region around it, mostly at its base. This region is characterized by a wrinkled surface and is the only site of the vitelline coat which specifically binds the lectin from Lotus tetragonolobus. The egg reacts explosively upon fertilization, ejecting vacuolar material from the crater. The role of this "egg reaction" in relation to the prevention of polyspermy is discussed.

Animals↗
PubMed1988

Immunocytochemistry and sperm pathology.

In this paper the Authors describe the localization of some significative proteins (acrosin, actin, tubulin, vimentin) detected by immunocytochemical methods in human infertile spermatozoa and correlate their distribution with the ultrastructural characteristics of the same spermatozoa, in order to clarify the structural bases of infertility.

Acrosome↗
PubMed1987

Action of gossypol on rat germinal cells. II. The acrosome.

The action of gossypol on the acrosomal complex in rats has been investigated by microscopical and submicroscopical methods. The drug displays its morphological action only on spermatozoa during the transit through the epididymis, causing malformations and vesiculations. It appears to exert a primary action on the S-S groups formation, disturbing morphological molding occurring in this period and inhibiting capacitation.

Acrosome↗
PubMed1984

Sperm morphogenesis, structure and function in humans over 70 years old.

Semen and testicular biopsy samples from different aged human donors have been examined for any age related changes in sperm morphogenesis, structure and function. Various abnormalities and defects, some being unique to spermatozoon of elderly men, were observed at the light and electron microscope levels. In spite of this, the best fractions of ejaculated spermatozoa population maintains his function, as demonstrated by some complete egg penetrations observed with the 'zona free' hamster egg test system.

Acrosome↗
PubMed1981

Human dynein and sperm pathology.

Human spermatozoa with normal structure and with different axonemal deficiencies (absence of axoneme, of arms, or of central structures) were studied by electron microscopy, SDS-polyacrylamide gel electrophoresis, and ATPase activity measurements. Normal human sperm possess a complement of high molecular weight polypeptides with an electrophoretic migration similar to that of sea urchin and other mammalian sperm dyneins. Human high molecular weight bands are numbered one to four in order of increasing of electrophoretic mobility; all of them are absent in spermatozoa that lack axoneme. The absence of doublet arms, coincides with the absence of bands 2, 3, and 4; the absence of central structures coincides with a reduction in intensity of band 2. In the latter two abnormal conditions, band 1 has an increased intensity. The data are tentatively interpreted by attributing the polypeptides forming bands 3 and 4 to the arm structure, whereas band 2 is supposed to contain a mixture of polypeptides localized in the arms and in the central structures; these abnormal sperm contain modified polypeptides which gather in band 1. Histochemical ATPase stainings indicate that this enzyme is localized mainly in the doublet arms and, to a minor extent, in the central structures.

Adenosine Triphosphatases↗
PubMed1981

Scanning electron microscopy and human sperm pathology.

This paper has been carried out in order to inquire whether some of the best known human malformations can be recognized by scanning electron microscopy. The SEM appearance of "straight tailed", "empty tailed", "short tailed", "round headed", "double", "old" human spermatozoa is described, and related to the inner structure. Straight tails and empty tails are quite evident at SEM. These defects are due to severe axonemal defects, related to dynein and tubulin deficiencies: "9+0", "arm less" and "axoneme less" spermatozoa are included in this category. Short tails and round heads are still more evident defects, due to complete absence of tail structures or acrosome and easily recognizable at SEM. Double spermatozoa are consistently in patients having abnormally high prolactin level and SEM is obviously sufficient for the diagnosis. Finally, spermatozoa in aged individuals show in SEM a peculiar shape due to absence of immature stages, reduced cytoplasm, disordered axoneme. It is concluded that SEM examination is a good tool for the identification of most of the best known human sperm abnormalities.

Electrophoresis↗
PubMed1979

"9 + 0" immotile spermatozoa in an infertile man.

In this paper the peculiar case of an infertile man, possessing only normally shaped, but stiff and immotile spermatozoa is described. All the sperm are conventionally structured, with the constant characteristic of the absence of central tubules and projections forming the so-called central sheath. Electrophoretic analysis of the high molecular weight polypeptide chains attributed to dyneins shows the constant absence of one chain. The importance of the central structure, usually belonging to the "9 + 2" model spermatozoa, and the possible localization of a dynein chain in this region are discussed.

Adult↗
PubMedDate not supplied

Further observations on the morphogenesis of the round headed human spermatozoa.

Sperm and testicular biopsies of an infertile human patient have been investigated using histochemical and electron microscopical technique. Spermiogram revealed a head defect, characterized with lacking acrosome and round and immature nucleoplasm, occuring in practically all cells and coiled tails in about a half of spermatozoa. EM study of spermatids has shown an abortive development of acrosome, whose primordium failed to attach the nucleus and expand, instead regressed. The nucleus failed in shaping and retarded in maturing, a disturbance apparently associated with the aplasia of hypoplasia of caudal manchette. The role of zinc in nuclear differentiation and the shape of head in the movement pattern are discussed.

Acrosome↗
PubMedDate not supplied

A possible haploid effect in acrosome malformations of human spermatozoa.

Acrosome malformations of spermatids and spermatozoa in the testes of two infertile patients were investigated with the light and electron microscope. The first visible abnormalities appear at early spermatid stages. The detailed morphological analysis of the malformed spermatids shows that in most cases only the differentiation of the acrosome granule is interfered with. This may be the origin of the malformations of the mature spermatozoa. The fact that almost half the early spermatids lack the acrosome granule suggests that the original cause is genetic and that the genes are expressed in the haploid phase.

Acrosome↗