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Biomedical subjects

A Neri

Publications and source records attributed to A Neri.

At least 19 recordsLinked to original sources
PubMed1995

Molecular analysis of cutaneous B- and T-cell lymphomas.

Among extranodal non-Hodgkin's lymphomas, primary cutaneous lymphomas (CLs) represent a consistent group of B- and T-cell malignancies. We investigated the arrangement of Ig and T-cell receptor (TCR) genes, together with the involvement of several oncogenes and the tumor-suppressor gene p53, in a panel of primary cutaneous B- and T-cell lymphomas (CBCLs and CTCLs). Southern blot analysis was performed to detect rearrangements of the Ig, c-myc, bcl-1, bcl-2, bcl-3, bcl-6, and the NFKB2/lyt-10 genes in 52 cases of CBCLs and of the TCR, bcl-3, and NFKB2/lyt-10 genes in 38 cases of CTCLs. tal-1 gene deletions were analyzed in CTCLs by means of polymerase chain reaction (PCR). p53 gene mutations were assayed using PCR, single-strand conformation polymorphism analysis, and direct DNA sequencing in CBCL and CTCL cases. Clonal rearrangements of Ig genes or oncogenes were found in 25 of the 52 CBCLs. In particular, we detected rearrangements of the bcl-1 locus (2 cases), the bcl-2 gene (2 cases), the NFKB2/lyt-10 gene (2 cases), and the bcl-6 gene (1 case); interestingly, 4 of these cases showed a germline arrangement of the Ig genes. Clonal rearrangements of TCR genes were detected in 37 of the 38 CTCLs. Rearrangements of the NFKB2/lyt-10 gene were present in 2 cases and tal-1 gene deletions in 3 CTCL cases; p53 gene mutations were detected in 1 CTCL case. Overall, our data indicate that (1) clonal rearrangement of Ig genes is frequently undetectable by means of Southern blot in CBCLs (60%); (2) genetic lesions are involved in a limited but significant fraction of primary CLs showing a molecular marker of clonality (13/62; 20%); and (3) rearrangements of the bcl-1, bcl-2, or bcl-6 loci, associated with specific subsets of nodal lymphoid neoplasias, are rarely observed in CBCLs. Moreover, our results suggest that tal-1 gene deletions may play a pathogenetic role in non-acute T-cell malignancies and that, in the context of lymphoid malignancies, CLs may represent a favorable target for the possible oncogenic potential of the NFKB2/lyt-10 gene.

Adult↗
PubMed1995

Microinjection of monoclonal antibody PAb421 into human SW480 colorectal carcinoma cells restores the transcription activation function to mutant p53.

The p53 tumor suppressor is a transcription factor frequently mutated in human malignancies. Tumor-derived p53 missense mutants are defective in sequence-specific DNA binding and fail to activate p53 target genes. mAb PAb421 was shown previously to restore DNA binding to selected p53 mutants in vitro. Here we show that mAb PAb421 when microinjected into human SW480 colorectal carcinoma cells restores the transcription activation function to the resident mutant p53 (arg to his 273, pro to ser 309). Codon 273 is the second most frequent p53 missense mutant found in human tumors. Our results lend support to the concept of restoring wild-type function to mutant p53 as a strategy for cancer therapy.

Antibodies, Monoclonal↗
PubMed1995

Structural and functional characterization of the promoter regions of the NFKB2 gene.

In order to clarify the transcriptional regulation of the NFKB2 gene (lyt-10, NF-kappa Bp100), we have characterized the structure and function of its promoter regions. Based on the nucleotide sequence of cDNA clones and the 5' flanking genomic region of the NFKB2 gene, RT-PCR analysis in a number of human cell lines demonstrated the presence of two alternative noncoding first exons (1a and 1b). Two distinct promoter regions, P1 and P2, were identified upstream of each exon, containing multiple sites of transcription initiation, as shown by RNase protection analysis. Sequence analysis of these regions showed a CAAT box upstream of exon 1a and high G-C content regions within both P1 and P2. Consensus binding sites for transcription factors, including SP1, AP1 and putative NF-kappa B (kappa B sites), were found upstream of each exon. In particular, six kappa B sites were identified, all but one of them capable of binding NF-kappa B complexes in vitro. Transfection in HeLa cells of plasmids containing P1 and P2 sequences linked to a chloramphenicol acetyltransferase reporter gene indicated that both P1 and P2 can act independently as promoters. Co-transfection of NF-kappa B effector plasmids (NF-kappa Bp52 and RelA) with a reporter gene linked to P1 and P2 showed that the NFKB2 promoter regions are regulated by NF-kappa B factors. RelA transactivates the NFKB2 promoter in a dose-dependent manner, whereas NF-kappa Bp52 acts as a repressor, indicating that the NFKB2 gene may be under the control of a negative feedback regulatory circuit.

Base Sequence↗
PubMed1995

Multiple genetic lesions in laryngeal squamous cell carcinomas.

BACKGROUND: To understand the molecular pathogenesis of laryngeal squamous cell carcinomas (LSCCs), this study investigated the involvement of various protooncogene loci (bcl-1, int-2, c-erbB-1, c-myc, ras) and the p53 tumor suppressor gene in 18 patients with LSCC (15 at clinical presentation, 3 in clinical relapse). METHODS: For all patients, the mutations affecting the p53 and the H-, K-, and N-ras genes were evaluated by polymerase chain reaction (PCR), single-strand conformation polymorphism, and the direct sequencing of PCR-amplified fragments. The bcl-1, int-2, c-erbB-1, and c-myc loci of 15 patients were investigated using Southern blot analysis. RESULTS: A mutation of the p53 gene was detected in 5/18 patients (approximately 28%), bcl-1 locus amplification in 4/15 (approximately 26%), c-erbB-1 locus amplification in 2/15 (approximately 13%), and c-myc locus amplification in 1/15 (approximately 6%). The simultaneous presence of more than one genetic lesion was observed in four patients; two showed int-2/bcl-1 coamplification, and two int-2/c-erbB-1 coamplification, one of whom also showed a p53 gene mutation. A novel p53 mutation involving the splice acceptor site of exon 6 was detected in one patient. Two of the five patients positive for p53 mutations had clinical relapses of primary tumors. bcl-1 locus amplification only was observed in patients with lymph node metastases (4/6). All but one of the patients with molecular genetic lesions showed a peculiar infiltrating pattern. CONCLUSIONS: Overall, these results show that alterations of known protooncogenes and the p53 tumor suppressor gene are involved in a large proportion of LSCCs (11/18; approximately 60%) and may suggest that distinct molecular pathways occur in the pathogenesis of these tumors.

Aged↗
PubMed1995

bcl-1, bcl-2, p53, c-myc, and lyt-10 analysis in cutaneous lymphomas.

In the present study we investigated the pathogenetic role of c-myc, bcl-2, and lyt-10 oncogenes, bcl-1 locus, and p53 suppressor gene in a representative panel of cutaneous lymphomas, including 25 cases of cutaneous B cell lymphoma (CBCL) and 29 cases of cutaneous T cell lymphoma (CTCL). In our analysis four cases of CBCL were found rearranged for bcl-2 and two for the bcl-1 locus. Two cases of CTCL and one case of CBCL were found rearranged for lyt-10. No rearrangements of c-myc oncogene were found in CBCL. Analysis of p53 gene showed mutation only in one case of mycosis fungoides in tumoral stage, at codon 163 of p53 gene (TAC-->CAC; Tyr--> Asp). Our data suggest that in primary CBCL bcl-2 oncogenes and bcl-1 locus are rarely involved. Furthermore, in primary CTCL p53 gene is not affected at significant frequency. The occurrence of p53 mutation in a patient affected by mycosis fungoides in tumoral stage may represent an involvement of p53 gene in tumor progression of CTCL, a finding observed in several types of human cancer.

Base Sequence↗
PubMed1995

Mutations in the coding region of c-myc occur independently of mutations in the regulatory regions and are predominantly associated with myc/Ig translocation.

Constitutive expression of c-myc resulting from a chromosomal translocation, which juxtaposes c-myc to an immunoglobulin gene, is a pivotal lesion in Burkitt's lymphomas. This deregulated expression of c-myc is associated with mutations in the regulatory regions, i.e. the first exon and the first intron of c-myc in tumors where the chromosomal breakpoint is not itself within the regulatory region. Until recently it was widely believed that the c-myc protein in these tumors is wild type. We have demonstrated that in a fraction of Burkitt's lymphomas from Africa and from the continental USA, and in mouse plasmacytomas, the c-myc gene carries mutations in the coding region. We now show that, occasionally, such mutations are also present in multiple myelomas--tumors which do not carry translocations or amplifications of c-myc. We also show that the frequency of the c-myc coding region mutations in BL is independent of the frequency of mutations in the regulatory region. These results suggest that the mechanisms that induce missense mutations involving the coding region of c-myc may be different from those that lead to mutations in the regulatory regions.

Burkitt Lymphoma↗
PubMed1995

Degradation of endothelial cell matrix collagen is correlated with induction of stromelysin by an activated ras oncogene.

A conditional expression system was established whereby the human K-ras, v-src, and v-mos genes were cloned into a conditional expression vector downstream of the dexamethasone-inducible mouse mammary tumor virus long terminal repeat. Rat-1 fibroblasts were transfected with these constructs and selected in medium containing G418. Cloned transfectants were isolated and characterized for absolute dependence on dexamethasone for expression of oncogene products and anchorage-independent growth in soft agar. Expression of activated p21K-ras(val12) enabled the fibroblasts to degrade extracellular matrix collagen secreted by murine microvessel endothelial cells. Concurrent with p21K-ras(val12) induction a proteinase with the characteristic size and substrate specificity of transin, the murine homologue of the human matrix metalloproteinase stromelysin, was expressed and secreted. Induction of v-mos and v-src oncogenes resulted in little or no detectable transin expression respectively coinciding with a relative or absolute failure to increase degradation of extracellular matrix collagen. This study suggests that in this system the expression of the ras oncogene can contribute to the in vitro invasive behavior of tumor cells by upregulating the production of a metalloproteinase capable of degrading collagen synthesized by vascular endothelial cells.

Animals↗
PubMed1995

Monoclonal antibodies against native ovarian tumor cells: specificity and characterization of the antigen. A preliminary report.

Monoclonal antibodies were prepared against native human ovarian carcinoma cells derived from the ascitic fluid of a patient (BH). One antibody, HC7R7, was selected on the basis of its binding to tumor BH cells, to other ovarian tumor cell lines (CAOV-3 and GZL-8), but not to the patient's fibroblasts. One hundred cell smears from ascitic and pleural effusions of tumor-suspected patients were immunostained with HC7R7. All serous ovarian carcinomas and half of the breast carcinomas stained positive with HC7R7; cells from noncancer ovarian aspirates were negative. Mesothelial cells were also stained with HC7R7. A correlation was noted between HC7R7 and OC-125 staining of ovarian tumor cells but not between HC7R7 and c-neu staining of breast tumor paraffin sections. The location of HC7R7-positive material in ovarian tumor cell lines (CAOV-3 and GZL-8) differed from that in the breast tumor cell line (MCF-7). CAOV-3 and GZL-8 showed membrane binding while, in MCF-7, not fully identified intracellular organelles were stained. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis and immunoblots from membrane and cytosol fractions of GZL-8 and MCF-7 showed HC7R7 binding to three protein bands in the membrane fraction and to three other bands in the cytosol, all in the 29- to 68-kDa range. Two of the bands were glycoproteins. The only band that was different in the GZL-8 and MCF-7 cells was a 43-kDa glycoprotein, which was more pronounced in the MCF-7 cells. The possible significance of the new HC7R7 antibodies for detection and survey of ovarian malignancies is discussed.

Aged↗
PubMed1995

Superovulation before IVF by recombinant versus urinary human FSH (combined with a long GnRH analog protocol): a comparative study.

PURPOSE: Gonal-F (Serono, Aubonne, Switzerland) is a recombinant human follicle stimulating hormone (FSH) synthesized in vitro by cells into which genes encoding for FSH subunits have been inserted. This preparation exhibits physiochemical, immunological, and pharmacological properties that bear great similarity to those of native human FSH. It has a high specific activity and can be administered subcutaneously. To compare the efficacy and safety of Gonal-F with those of urinary human FSH (Metrodin; Serono) in achieving superovulation for IVF purposes in a prospective, randomized study. METHODS: Twenty infertile patients (normo-ovulatory healthy women) were recruited for the study and allocated at random to the Gonal-F or Metrodin groups. The treatment protocol consisted of pituitary down regulation by GnRH analog (Buserelin; Hoechst, Frankfurt, Germany) employing the "long" protocol initiated at the mid-luteal phase (900 micrograms/day, intranasal administration). Gonal-F (SC) or Metrodin (IM) was injected daily (225 IU/day) starting on cycle day 3. Dose adjustment was performed, when necessary, from cycle day 7. RESULTS: Of the 20 cycles analyzed, none was canceled due to poor response. No cases of adverse effects (including local intolerance) or ovarian hyperstimulation syndrome were recorded in either group. They did not differ significantly in the following treatment-dependent variables: hormone profile, duration of FSH treatment, total FSH dose required to achieve follicular maturation, and the number of oocytes retrieved, fertilized, and replaced. CONCLUSIONS: These preliminary data concur with previous studies in demonstrating that Gonal-F is as effective and safe as Metrodin (when given in combination with a "long" protocol of GnRH analog) in inducing controlled ovarian hyperstimulation for IVF purposes. Its mode of administration (SC instead of IM) offers an additional advantage over the urinary human FSH.

Adolescent↗
PubMed1995

Great grand multiparity--beyond the 10th delivery.

OBJECTIVE: To investigate the perinatal outcome and obstetric complications of women delivering for the 10th time or more. METHODS: Four hundred twenty women of great grand multiparity were analyzed in a modern health care setting and compared with our general population of obstetric patients, with regard to past history, maternal age, gestational age, mode of delivery, fetal outcome and intercurrent medical/obstetric problems. RESULTS: The study group showed significantly lower rates of low birth weight infants and instrumental delivery. No significant difference was seen in the incidence of cesarean section, pathologic fetal presentation, maternal hypertension, gestational diabetes, hemorrhage, or perinatal morbidity or mortality. There was a slightly higher incidence of twin births compared with the general population. CONCLUSION: It is probable that women capable of reaching their 10th delivery are basically healthy. If offered adequate perinatal care, they are not a high-risk group during subsequent deliveries.

Adult↗
PubMed1995

Successful external version of B-twin after the birth of A-twin for vertex--non-vertex twins.

OBJECTIVE: To determine the optimal intrapartum management of twins, especially those in vertex--non-vertex presentation. STUDY DESIGN: The study population consisted of 408 sets of twins delivered between 1988 and 1992, weighing at birth over 1500 g. According to our protocol, vaginal delivery was attempted in the vertex-vertex presentations. If non-vertex presentation was first, we performed cesarean section. In vertex--non-vertex cases, the first was delivered vaginally and external cephalic version or breech delivery was performed on the second. Apgar scores were compared according to presentation and delivery mode. RESULTS: Vaginal delivery was accomplished in 122 (73%) of 169 vertex--vertex presentations, 96 (68%) of 142 vertex--non-vertex presentations, and 4 (5%) of 99 non-vertex--other presentations. External cephalic version (ECV) of the second twin and subsequent vaginal delivery in vertex--non-vertex was successful in 75% of cases, and internal podalic version and assisted breech delivery were performed in 20 cases, and the remaining two were delivered by cesarean section. Apgar scores were not significantly different among the various groups, and no complications arose from external cephalic version performed on second non-vertex twins. CONCLUSIONS: External cephalic version was found safe for delivering second non-vertex twins in cases where the first twin is in vertex presentation. In our opinion routine cesarean section is thus no longer justified in such cases.

Delivery, Obstetric↗
PubMed1995

Membranous dysmenorrhea: the forgotten entity.

BACKGROUND: Membranous dysmenorrhea involves the spontaneous slough of the endometrium in one cylindrical or membranous piece that retains the shape of the uterine cavity. Because this entity is rarely mentioned in the medical literature, the purpose of this report is to describe two such cases. CASES: An 18-year-old nullipara with regular menstrual cycles presented with membranous dysmenorrhea after taking the contraceptive Gynera (Gestodene 0.075 mg, ethinyl estradiol 0.030 mg). Symptoms disappeared when the medication was discontinued. The second patient, a 26-year-old woman, gravida 1, para 1, was on a 10-day monthly regimen of Provera (medroxyprogesterone acetate) 2.5 mg/day for dysfunctional uterine bleeding. When the Provera dose was increased to 10 mg/day, the symptoms disappeared. CONCLUSION: Membranous dysmenorrhea is "a disease of theories" with various recommended medications. When this condition is caused by iatrogenic treatment, the best approach is to discontinue the offending drug or change its dosage.

Adolescent↗
PubMed1995

The grand multipara.

Grandmultiparity (GMP) has long been considered an obstetric complication for both mother and fetus, although recent studies indicate that, with proper perinatal care, women with high-parity rates are no longer at high risk. The current study examines the outcome of delivery in 1700 women in their fifth or more delivery, as compared with two control groups: 622 primiparas and 735 multiparas (two to three previous deliveries). Excellent prenatal care was available free of charge to all parturients. Our objectives were to evaluate the management of GMP in contemporary obstetrics and to assess whether grand multiparas are still high-risk patients. The age of the grandmultiparas was significantly higher compared with with the control groups, which may explain the higher incidence among them of antenatal medical disorders, such as diabetes mellitus and hypertensive disease. No significant differences were found among the three groups for preterm or post-term births, small-for-gestational-age infants, polyhydramnios, oligohydramnios, perinatal death, fetal distress, multiple births, placenta previa, abruptio placentae or cord prolapse. Macrosomia was markedly higher in the grandmultiparas and multiparas than in nulliparas. Thus, our results indicate that good perinatal care can ensure better results in grandmultiparas, and that grandmultiparity no longer needs to be considered a high-risk obstetric category in our population.

Adult↗
PubMed1995

Cervical polyp in the menopause and the need for fractional dilatation and curettage.

OBJECTIVE: To investigate the need for fractional dilatation and curettage following excision of symptomatic versus asymptomatic cervical polyps. STUDY DESIGN: A prospective study was carried out on 467 women who were referred for treatment of symptomatic (accompanied by vaginal bleeding or discharge) or asymptomatic cervical polyps, from January 1, 1990 to December 31, 1992. Of these, 204 were premenopausal and 263 postmenopausal. Every excision of a cervical polyp was followed by a dilatation and curettage. The histological data were evaluated statistically using the chi 2-test. RESULTS: Postmenopausal women had more asymptomatic than symptomatic cervical polyps (P = 0.004). Cervical polyps were associated with more endometrial polyps in the postmenopausal than in the premenopausal women (P = 0.0009). Postmenopausal women with symptomatic cervical polyps had more endometrial abnormalities on histological examination than those with asymptomatic ones (P < 0.0001); this difference was not significant in the premenopausal group (P = 0.49). CONCLUSIONS: While neither symptomatic nor asymptomatic cervical polyps are an indication for dilatation and curettage (following excision) in women in their reproductive years, and do not affect their management or prognosis, this is not the case in postmenopausal women. Symptomatic cervical polyps after the menopause must be excised and followed by mandatory fractional dilatation and curettage, because there is a marked incidence of associated severe pathological conditions in this age group.

Adult↗
PubMed1995

Ras-dependent maturation of Xenopus oocytes is blocked by modified peptides of GTPase activating protein (GAP).

Guanosine triphosphatase activating protein (GAP) is an important modulator of p21ras (Ras)-dependent signal transduction in mammalian cells and in insulin-induced maturation of Xenopus oocytes. A synthetic octapeptide from the catalytic domain of GAP, residues 899-906 (F899VFLRLIC906), inhibited GAP-stimulated hydrolysis of GTP to GDP by Ras in an in vitro biochemical assay (IC50 = 12 microM). The peptide was assayed for its ability to block insulin- (Ras-dependent) and progesterone- (Ras-independent) induced maturation of stage VI Xenopus laevis oocytes, marked by germinal vesicle breakdown (GVBD). Microinjection of 50 pmol of the peptide inhibited insulin- but not progesterone-induced GVBD by 50%. A 7-residue peptide lacking F899, GAP(900-906)-NH2, failed to inhibit GAP-stimulated GTPase activity and did not block GVBD. Replacement of the cysteine residue at position 906 with methionine resulted in a peptide with prolonged inhibitory activity in the oocyte. Moreover, sequential replacement of specific L-amino acid residues with the corresponding D-amino acids produced a peptide with a two-fold increased half-life after injection into oocytes. None of the peptides tested affected progesterone induced GVBD, suggesting that the modifications did not result in loss of specificity. These studies show that (a) peptides that were able to inhibit GAP-stimulated Ras GTPase activity in vitro were also able to block Ras-dependent GVBD in oocytes, and (b) specific substitutions in these peptides can result in improved stability in oocytes.

Amino Acid Sequence↗
PubMed1995

Rearranged NFKB-2 genes in lymphoid neoplasms code for constitutively active nuclear transactivators.

The NFKB-2 gene codes for an NF-kappa B-related transcription factor containing rel-polyG-ankyrin domains. Chromosomal rearrangements of the NFKB-2 locus have been found in various types of lymphoid neoplasms, suggesting that they may contribute to lymphomagenesis. Rearrangements cluster within the 3'-terminal ankyrin-encoding domain of the NFKB-2 gene and lead to the production of C-terminally truncated proteins which, in some cases, are fused to heterologous protein domains. In order to determine the functional consequences of these alterations, we have analyzed the subcellular localization, DNA binding, and transcriptional activity of two representative tumor-associated mutants in which the ankyrin domain is either terminally truncated (NFKB-2p85) or truncated and joined to an out-of-frame immunoglobulin C alpha domain (lyt-10C alpha). Immunofluorescence studies performed on cells transfected with p85 or lyt-10C alpha expression vectors showed that both the abnormal proteins were constitutively localized in the nucleus. Immunoprecipitation analysis of UV-cross-linked DNA-protein adducts showed that p85 can bind kappa B sites in its unprocessed form. Cotransfection of p85 or lyt-10C alpha expression vectors with kappa B-driven reporter plasmids showed that both p85 and lyt-10C alpha have retained the ability to mediate transcriptional activation via heterodimerization with Rel-Ap65 but have lost the transrepression activity associated with homodimeric DNA binding. Furthermore, both p85 and lyt-10C alpha were capable of independent transactivation of kappa B-reporter genes and this activity could not be further stimulated by Bcl-3. These abnormal proteins may contribute to lumphomagenesis by determining a constitutive activation of the NF-kappa B system and, in particular, of NFKB-2 target genes.

Ankyrins↗