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Biomedical subjects

E Martini

Publications and source records attributed to E Martini.

At least 37 records · Page 2Linked to original sources
PubMed1999

Usefulness of screening for congenital or acquired hemostatic abnormalities in women with previous complicated pregnancies.

Activated protein C resistance (APCR) is a common cause of familial thrombophilia and venous thrombosis. The aim of the study was to investigate the prevalence of APCR associated with factor V Leiden mutation and its relevance in comparison to other risk factors for thromboembolic disorders in women with a history of previous complicated pregnancies (history of fetal loss in the second and third trimester n = 34, preeclampsia n = 46). The frequency of APCR was significantly higher in women with a history of fetal loss and preeclampsia (23.5 and 26.1%, respectively) compared with a control group (3.8%). The prevalence of antithrombin, protein C and protein S deficiencies and the presence of antiphospholipid antibodies were also investigated: the prevalence of at least one disorder was 41.2% in the group with previous fetal loss, 37.0% in the group with previous preeclampsia and 7.5% in the control group.

Activated Protein C Resistance↗
PubMed1998

Recruitment of phosphorylated chromatin assembly factor 1 to chromatin after UV irradiation of human cells.

The subcellular distribution and posttranslational modification of human chromatin assembly factor 1 (CAF-1) have been investigated after UV irradiation of HeLa cells. In an asynchronous cell population only a subfraction of the two large CAF-1 subunits, p150 and p60, were found to exist in a chromatin-associated fraction. This fraction is most abundant during S phase in nonirradiated cells and is much reduced in G2 cells. After UV irradiation, the chromatin-associated form of CAF-1 dramatically increased in all cells irrespective of their position in the cell cycle. Such chromatin recruitment resembles that seen for PCNA, a DNA replication and repair factor. The chromatin-associated fraction of p60 was predominantly hypophosphorylated in nonirradiated G2 cells. UV irradiation resulted in the rapid recruitment to chromatin of phosphorylated forms of the p60 subunit. Furthermore, the amount of the p60 and p150 subunits of CAF-1 associated with chromatin was a function of the dose of UV irradiation. Consistent with these in vivo observations, we found that the amount of CAF-1 required to stimulate nucleosome assembly during the repair of UV photoproducts in vitro depended upon both the number of lesions and the phosphorylation state of CAF-1. The recruitment of CAF-1 to chromatin in response to UV irradiation of human cells described here supports a physiological role for CAF-1 in linking chromatin assembly to DNA repair.

Animals↗
PubMed1998

Detection of structural abnormalities in spermatozoa of a translocation carrier t(3;11)(q27.3;q24.3) by triple FISH.

Structural chromosome abnormalities in spermatozoa represent an important category of paternally transmittable genetic damage. A couple was referred to our centre because of repetitive abortions and the man was found to be a carrier of a reciprocal translocation t(3;11)(q27.3;q24.3). A tailored fluorescence in situ hybridisation (FISH) approach was developed to study the meiotic segregation patterns in spermatozoa from this translocation carrier. A combination of three DNA probes was used, a centromeric probe for chromosome 11, a cosmid probe for chromosome 11q and a YAC probe for chromosome 3q. The frequency of spermatozoa carrying an abnormal chromosome constitution was compared with baseline frequencies in control semen specimens and it was found that a significantly higher percentage of spermatozoa carried an abnormal constitution for the chromosomes involved in the translocation. A normal or balanced chromosome constitution was found in 44.3% of the analysed spermatozoa, while the remainder exhibited an abnormal chromosome constitution reflecting different modes of segregation (15.9% adjacent I segregation, 6.5% adjacent II segregation, 28.9% 3:1 segregation, 0.8% 4:0 segregation, 3.6% aberrant segregation). The frequency of aneuploidy for chromosomes X, Y, 13 and 21 was assessed using specific probes but there was no evidence of interchromosomal effects or variations in the sex ratio in spermatozoa from the translocation carrier. In conclusion, structural aberrations can be reliably assessed in interphase spermatozoa using unique DNA probe cocktails, and this method provides insight into the genetic constitution of germ cells and enables evaluation of potential risks for the offspring.

Adult↗
PubMed1997

Dystonia as an isolated symptom of multiple sclerosis?

Sustained dystonia has seldom been reported during the course of multiple sclerosis (MS) [5-8, 10], and has been described as the first manifestation of the disease in only three cases [1,3]. We describe a patient with a diagnosis of laboratory-supported, defined MS in which sustained dystonia was the only neurological symptom.

Brain↗
PubMed1997

Analysis of unfertilized oocytes subjected to intracytoplasmic sperm injection using two rounds of fluorescence in-situ hybridization and probes to five chromosomes.

Chromosomal aberrations are the major cause of pre- and post-implantation embryo wastage and some studies suggest that half of all human conception have a chromosomal abnormality. Analysis of gametes provides information on the origin of these chromosomal aberrations. The purpose of this study was to develop a reliable multi-probe fluorescence in-situ hybridization (FISH) procedure that would enable us to investigate aneuploidy in unfertilized oocytes subjected to intracytoplasmic sperm injection (ICSI). Oocytes were spread with HCl and Tween 20 solution, and then two rounds of triple-probe FISH were performed on each oocyte using directly-labelled centromeric probes: chromosomes 1, 7, 15 (overnight hybridization); chromosomes 1, X, Y (2 h hybridization). After the first round, the slides were counterstained and evaluated, and the positions of FISH signals were recorded. For the second round, the counterstain was removed and the second probe cocktail was applied. The chromosome 1 probe was an internal control for the two hybridization procedures, while the Y chromosome probe was used to detect sperm DNA. To evaluate the method, a total of 79 oocytes from 27 patients were studied. Of these, 67 (84.8%) were successfully spread and 97% of these oocytes exhibited discernible FISH signals. Upon lysis, oocytes exhibited one or more DNA fragments (mean 1.9, range 1-3). Of the 65 analysable oocytes, 17 (26.2%) displayed a normal haploid chromosome constitution with paired spots for the two chromatids. A further 23 oocytes (35.4%) showed an ambiguous chromosome complement due to an abnormal number of DNA fragments which may have resulted from loss of DNA during spreading or to an abnormal oocyte, while 25 oocytes (38.4%) displayed aneuploidy for one or more of the chromosomes studied. In conclusion, this new approach is a quick and efficient method with which numerical chromosomal abnormalities in human oocytes can be studied; interpretation of the patterns of DNA fragments and FISH signals requires further clarification.

Aneuploidy↗
PubMed1997

Comparison of gonosomal aneuploidy in spermatozoa of normal fertile men and those with severe male factor detected by in-situ hybridization.

The purpose of the study was to analyse the frequency of sex-chromosome numerical abnormalities in human spermatozoa of infertile men by using a standardized experimental protocol of double target in-situ hybridization (ISH). The experiments were performed on decondensed sperm heads from 15 infertile patients (six cases of unexplained infertility and nine cases of severe oligoasthenoteratozoospermia). Three men of proven fertility were used as controls. The probes employed recognized the centromeric regions of human X chromosome and the long arm of the Y chromosome. In a smaller number of cases, additional experiments of double ISH were performed using centromeric probes for chromosomes 1 and 17. Signal detection was based on protocols of enzymatic cytochemical reactions. A total of 24,508, 24,679 and 42,285 cells were scored in the control, unexplained infertility and severe male factor groups of patients respectively. In all the patients in the ISH efficiency result was approximately 98%. In controls, unexplained infertility and severe male factor patients, the frequency of morphologically normal sperm cells carrying an abnormal chromosome constitution (XX or YY or XY or > 2 sex chromosomes signals) was 0.86, 0.75 and 1.35% respectively. The value of this last group of patients (severe male factor) was significantly higher than in the other two groups of patients (P < 0.008). The same findings were made using the autosomic probes. Our preliminary data support the possibility of an increased risk from paternal origin sex chromosome aneuploidies in children born after intracytoplasmic sperm injection (ICSI). Further investigations of the cytogenetic constitution of spermatozoa from severe male factor patients is warranted.

Aneuploidy↗
PubMed1996

Capsule contraction after continuous curvilinear capsulorhexis.

We report two cases of capsular bag contraction that occurred within 1 month after continuous curvilinear capsulorhexis, phacoemulsification, and intraocular lens implantation. Neither patient had a known risk for this complication. Both patients had a neodymium:YAG laser anterior capsulotomy, which disrupted the capsulorhexis margin and led to prompt capsular bag distension.

Adult↗
PubMed1996

Constitution of semen samples from XYY and XXY males as analysed by in-situ hybridization.

A brightfield microscopical in-situ hybridization (ISH) technique was applied to semen samples of two 47,XYY males, one 46,XY/47,XXY/XXY male with fertility problems, and two normal 46,XY men, who served as controls. The use of a standardized nuclear DNA decondensation method, together with double-target ISH and morphological staining, allowed an accurate study of the sex chromosomal content and morphology of spermatozoa. In the males carrying an extra sex chromosome, we detected X- and Y-bearing spermatozoa in a ratio which did not differ significantly from the 1:1 ratio found in normal males. Aneuploidy for the sex chromosomes was found in approximately 15% of the spermatozoa of both XYY males and in 3% of the XXY male. The most striking finding was the relatively low percentage of spermatozoa in these patients, with an average of 65% in the XYY males and 84% in the XXY male. The other cells represented immature germ cells (IGC), including spermatogonia and spermatocytes arrested at various stages of spermatogenesis. Apparently, in XYY or XXY men, these IGC are shed into the semen to an increased extent as compared to normal, fertile men. The sex chromosome constitution of these IGC was heterogeneous. However, the finding that the majority of spermatozoa in semen of 47,XYY and 47,XXY males carried a single sex chromosome strengthens the hypothesis that a 46,XY germ cell line must be present, apparently with a proliferative advantage over the 47,XYY or 47,XXY cells.

Adult↗
PubMed1995

Application of different in-situ hybridization detection methods for human sperm analysis.

The detection of some types of aneuploidy in human spermatozoa can be based on the use of the fluorescence in-situ hybridization technique (FISH). One of the crucial steps for FISH is to achieve a proper decondensation and denaturation of the DNA in the specimen, so as to obtain efficient hybridization results. However, after DNA decondensation the morphology of sperm heads is partly distorted and the majority of the tails is lost. This situation leads to problems in the distinction between disomic and diploid spermatozoa, as well as between abnormal spermatozoa and somatic cells. Double- and triple-target FISH can partly solve this discrimination problem. To improve these procedures we adapted the steps of decondensation and visualization of the single sperm cells. Firstly, DNA decondensation with 25 mM dithiothreitol in 1 M Tris at pH 9.5 resulted in sperm cells with intact morphology of both the head and the tail, and allowed efficient single-, double- and triple-target ISH to be performed. Secondly, we applied a novel detection method, based on enzyme immunocytochemical reactions, with coloured precipitation products. Thirdly, this ISH procedure was combined with Diff-Quik staining and bright-field microscopy. This absorption method has the advantage of a permanent signal, and the adapted cytoplasmic staining of the sperm plasma membrane allows the visualization of the outline of the single spermatozoon. Using this approach, therefore, it is possible to discriminate between disomic, diploid and abnormal spermatozoa, somatic cells and spermatozoa that overlap, because the morphology of the cells is not distorted and the tails of the spermatozoa are intact and properly visualized.

Cell Nucleus↗
PubMed1995

Brain pathology and strabismus.

If we consider the complex and articulate organization of the oculomotor neural system, ie, infranuclear, nuclear, internuclear, and supranuclear levels, how many neuronal structures are implicated and their widespread localization in the central nervous system, and if we understand the various relationships within the oculomotor system and with other cerebral structures, we may easily realize that cerebral diseases and oculomotor disturbances are tightly and reciprocally connected. Many diseases may be associated with ocular movement impairment, sometimes acting on different sites of oculomotor organization. These alterations may have a clear pathophysiologic meaning and a relevant topographic localizing value, otherwise correlations and mechanisms are simply hypothetical. Last but not least for conceptual relevance are the modifications of neuronal anatomy and physiopathologic mechanisms induced by the strabismus. In the past year many articles have been published that analyze the relationships and the pathogenetic role of cerebral anomalies in the context of strabismus syndromes. Of outstanding interest is the proof of cortical and subcortical neural stations' plasticity, and the evidence of a cerebral anatomophysiologic basis of strabismus and amblyopia. In this context the midbrain, pontine, and brain stem nuclei and neuronal organizations have a peculiar importance. We will try to systematically expose, even if briefly, the main contributions in this area.

Brain↗
PubMed1995

[Epidemiology of hepatitis C virus infection in hemodialysis. A study of the Gargano area].

In order to evaluate epidemiological features of hepatitis C virus infection in patients with chronic renal failure, we enrolled 80 haemodialyzed subjects in four centers of Gargano area (Southern Italy). In a 28 months follow-up we checked antiHCV antibodies by EIA II and viraemia by polymerase chain reaction. Seroprevalence of HCV infection was 35%, while incidence was 2.4%/year; viraemia was detected in 62.5% of antiHCV+ and in only one of antiHCV-. In our opinion there is a definitive need of special precautions (or isolation of antiHCV+) in haemodialysis units to avoid community-acquired HCV infection.

Adult↗
PubMed1993

[The pitfalls of lymphocyte immunophenotyping during HIV infection].

Preferential infection of CD4+ lymphocytes by HIV, related to both direct and indirect mechanisms, leads to progressive decrease in this population. A CD4 lymphocyte count has become the preferential test for monitoring the infection. Thus, a flow cytometry laboratory handles a great number of phenotyping prescriptions that require accuracy and precision. The technical and biological parameters involved are listed, and some rules for interpretation of results given. Because no standardization exists and because cytometers are not automated, there is often great variability between laboratory results. We show that variability can be decreased by the use of correct procedures for analysis on the cytometer (especially for fluorescence interpretation). On the other hand, many biological factors have a significant effect on the results. A list of these factors is given: circadian rhythm, other infectious diseases and drugs. Lastly, the distribution of values in normal subjects is reported. The wide range shows that results from a patient must be compared with previous values to determine the course of the infection. These data would help in defining and interpreting results.

Adult↗
PubMed1992

Characterization of the liver cytosol antigen type 1 reacting with autoantibodies in chronic active hepatitis.

An autoantibody to liver cytosol was previously described in childhood autoimmune chronic active hepatitis type 2. The antigen, liver cytosol antigen type 1, was for the first time partially purified using gel filtration and ion exchange chromatography, and it was characterized using immunodiffusion, immunoblot and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the immunoprecipitate. Immunoblot detected a unique antigenic peptide at 62 kD from human cytosol and at 58 kD from rat cytosol. The same peptides were also detected when immunoprecipitates of liver cytosol antigen type 1 and autoantibodies to liver cytosol antigen were submitted to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A polymeric structure, probably a tetramer, is suggested for native liver cytosol antigen type 1 because in gel filtration chromatography liver cytosol antigen type 1 was eluted as a protein of a molecular weight between 240 and 290 kD when human liver cytosol was fractionated and between 220 and 270 kD from rat liver cytosol. Liver cytosol antigen type 1 is probably poor in carbohydrates because it was not stained by periodic acid-Schiff stain. The autoantibodies to liver cytosol were frequently found in association with antiliver kidney microsomal autoantibodies type 1, which are directed against the cytochrome P-450 of the IID6 subfamily. Antiliver kidney microsomal autoantibodies type 1 but not antiliver cytosol autoantibodies were found in association with antibodies to hepatitis C virus. Autoantibodies to liver cytosol antigen type 1 seem to be a more specific marker for autoimmune hepatitis type 2 than antiliver kidney microsomal antibodies type 1 autoantibodies.

Animals↗