Biomedical subjects

M Napolitano

Publications and source records attributed to M Napolitano.

At least 37 records · Page 2Linked to original sources

PubMed2000

I-309 binds to and activates endothelial cell functions and acts as an angiogenic molecule in vivo.

Several chemokines have been shown to act as angiogenic molecules or to modulate the activity of growth factors such as fibroblast growth factor 2 (FGF-2) and vascular endothelial growth factor (VEGF). The detection of the CC chemokine receptor (CCR) 8 message in human umbilical vein endothelial cells (HUVECs) by reverse transcription- polymerase chain reaction (RT-PCR) and RNase protection assay (RPA), prompted us to investigate the potential role exerted by the CC chemokine I-309, a known ligand of such receptor, in both in vitro and in vivo angiogenesis assays. We show here that I-309 binds to endothelial cells, stimulates chemotaxis and invasion of these cells, and enhances HUVEC differentiation into capillary-like structures in an in vitro Matrigel assay. Furthermore, I-309 is an inducer of angiogenesis in vivo in both the rabbit cornea and the chick chorioallantoic membrane assay (CAM).

Allantois↗

PubMed2000

Intermediate dose recombinant interferon-alpha as second-line treatment for patients with recurrent cutaneous melanoma who were pretreated with low dose interferon.

BACKGROUND: Interferon (IFN) is widely considered the most effective agent in the adjuvant therapy of patients with cutaneous melanoma (CM). However, little is known about the effect of IFN on pretreated CM patients who experience disease recurrence. The authors conducted a Phase II study to determine whether intermediate doses of IFN could be beneficial for these patients. METHODS: A series of 24 consecutive CM patients who had undergone surgery for local, in-transit, or lymph node disease recurrence during adjuvant therapy with low dose IFN (IFNalpha-2b, 3 million units [MU] per day, three times per week) were enrolled for second-line therapy with intermediate dose IFN (IFNalpha-2b, 10 MU per day) for one year. RESULTS: IFN was discontinued in 7 patients (29.2%) because of toxicity. Several patients complained of impairment in their daily activities. Progression of disease was registered in 17 patients (70. 8%), with a median disease free survival of 5.5 months (95% confidence interval, 3.4-14.2). The median follow-up for the 7 patients who did not experience disease recurrence was 15 months (range, 13-22 months). CONCLUSIONS: An increased dose of IFN as second-line adjuvant treatment was poorly tolerated and produced negative clinical outcomes in patients with CM. However, these patients probably were unresponsive to IFN regardless of the dosage level. In fact, the first adjuvant IFN treatment was ineffective in all patients. Thus, the key factor in the treatment of CM seems to be patient responsiveness to IFN rather than the total dosage achieved.

Adult↗

PubMed2000

Estradiol induces functional inactivation of p53 by intracellular redistribution.

Estrogen treatment of MCF-7 cells grown in serum-free medium induced a modification of the intracellular distribution of p53 protein. Western blot analysis and immunofluorescence staining showed that p53 was localized in the nucleus of untreated cell and that after 48 h of hormone treatment, it was mostly localized in the cytoplasm. This effect was blocked by the antiestrogen ICI182,780. Intracellular redistribution of p53 was correlated to a reduced expression of the WAF1/CIP1 gene product and to the presence of degradation fragments of p53 in the cytosol. Estradiol treatment prevented the growth inhibition induced by oligonucleotide transfection, simulating DNA damage. This observation indicated that the wild-type p53 gene product present in the MCF-7 cell could be inactivated by estradiol through nuclear exclusion to permit the cyclin-dependent phosphorylation events leading to the G1-S transition. In addition, the estradiol-induced inactivation of p53 could be involved in the tumorigenesis of estrogen-dependent neoplasm.

Blotting, Western↗

PubMed2000

Second line chemotherapy with docetaxel in patients with recurrent malignant glioma: a phase II study.

The objective of the study was to assess the efficacy of docetaxel in recurrent supratentorial malignant gliomas. The sample size of the study was determined by the Gehan's method for a response rate of 20% and a beta error of 5%. In the first step 14 patients (age 27-69, median 50; Karnofsky index 50-90, median 75) with recurrent malignant glioma after surgery, radiotherapy and nitrosourea, were enrolled (12 glioblastomas, 2 anaplastic astrocytomas). Docetaxel at the initial dose of 80 mg/m2 was administered every 3 weeks until progression or unacceptable toxicity. A total of 41 cycles was administered. Patients received a median of two cycles (range 1-6). No complete or partial response was observed. Therefore, according to the design of the study, no additional patients were enrolled and the trial was terminated. Two stabilizations were observed (14 and 15 weeks). Median TTP was 7 weeks (44 days). Median overall survival from recurrence was 26.5 weeks (6.4 months). Grade 3-4 neutropenia was observed in 8 patients (57%) but no life-threatening toxicity was observed. Other toxicities were uncommon and mild. Dose reduction was performed in 5 patients. This study suggests that docetaxel displayed no significant activity in patients with malignant recurrent gliomas.

Adult↗

PubMed2000

Tissue plasminogen activator controls multiple forms of synaptic plasticity and memory.

Induction of long-term depression (LTD) in rat striatal slices revealed that this form of synaptic plasticity is coupled to an increased expression of tissue-plasminogen activator (t-PA) mRNA, as detected by the mRNA differential display technique. To further investigate the involvement of this gene in synaptic remodelling following striatal LTD, we recorded electrical activity from mice lacking the gene encoding t-PA (t-PA-KO) and from wild-type (WT) mice. Tetanic stimulation induced LTD in the large majority of striatal neurons recorded from WT mice. Conversely, LTD was absent in a significant proportion of striatal neurons obtained from mice lacking t-PA. Electrophysiological recordings obtained from hippocampal slices in the CA1 area showed that mainly the late phase of long-term potentiation (LTP) was reduced in t-PA-KO mice. Learning and memory-related behavioural abnormalities were also found in these transgenic mice. Disruption of the t-PA gene, in fact, altered both the context conditioning test, a hippocampus-related behavioural task, and the two-way active avoidance, a striatum-dependent task. In an open field object exploration task, t-PA-KO mice expressed deficits in habituation and reactivity to spatial change that are consistent with an altered hippocampal function. Nevertheless, decreased rearing and poor initial object exploration were also observed, further suggesting an altered striatal function. These data indicate that t-PA plays a critical role in the formation of various forms of synaptic plasticity and memory.

Animals↗

PubMed2000

Expression and relationship between endothelin-1 messenger ribonucleic acid (mRNA) and inducible/endothelial nitric oxide synthase mRNA isoforms from normal and preeclamptic placentas.

Preeclampsia is a mainly vascular disease of pregnancy, probably caused by an imbalance between vasodilator and vasoconstrictor agents that results in generalized vasospasm and poor perfusion in many organs. Among these factors, endothelin-1 (ET-1), a potent vasoconstrictor, is highly increased in preeclamptic women, while nitric oxide (NO), a vasodilator of human utero-placental arteries, is reduced in the same patients. The present study was designed to investigate the interactions between ET-1 and the NO system in the feto-placental unit; to this purpose we also examined the messenger ribonucleic acid (mRNA) expression of ET-1, inducible NO synthase (iNOS), and endothelial NOS (eNOS) in human cultured placental trophoblastic cells obtained from preeclamptic (PE) and normotensive (NT) pregnancies. We also studied whether exogenous ET-1 may affect the expression of iNOS and eNOS in human placental trophoblastic cells. Interestingly, by Northern blot analysis we observed an increased ET-1 mRNA expression level in PE trophoblastic cells compared to NT trophoblastic cells. Furthermore, exogenous ET-1 (10(-7) mol/L) was able to up-regulate its own mRNA expression in both NT and PE trophoblastic cells. iNOS and eNOS mRNA expression was then detected, by semiquantitative PCR, in both NT and PE trophoblastic cells. PE trophoblastic cells expressed lower iNOS mRNA levels compared with NT pregnancies. On the contrary, eNOS mRNA expression was higher in PE trophoblastic cells than in NT cells. Moreover, in the presence of ET-1 we observed a decrease in iNOS and an increase in eNOS mRNA expression levels in both NT and PE trophoblastic cells compared with the respective untreated cells. In conclusion, we demonstrate that ET-1 expression is increased in PE cells, whereas iNOS, which represents the main source of NO synthesis, is decreased; conversely, eNOS expression is increased. Finally, ET-1 is able to influence its own as well as NOS isoform expression in normal and PE trophoblastic cultured cells. These findings suggest the existence of a functional relationships between ET(s) and NOS isoforms that could constitute the biological mechanism leading to the reduced placental blood flow and increased resistance to flow in the feto-maternal circulation, which are characteristic of the pathophysiology of preeclampsia.

Adult↗

PubMed2000

[Corticosteroid-induced epidural lipomatosis].

Epidural lipomatosis is a rare disease, most often associated with chronic administration of exogenous steroids. We report the case of a 69-year-old man treated with 20mg prednisolone daily for 11 years because of polyarthritis. The patient complained of back pain associated with severe weakness of his lower limbs and brisk reflexes, with a progressive onset over one year. MRI showed epidural lipomatosis narrowing the epidural spaces from T-3 to T-10. Tapering of steroids was associated with slow but positive resolution of his symptoms.

Aged↗

PubMed1999

Modulation of gene expression following long-term synaptic depression in the striatum.

A number of behavioural and cellular studies have suggested that activity-dependent synaptic plasticity associated with learning and memory may lead to the expression of various genes whose protein products can play a critical role in memory acquisition and consolidation. Long-term potentiation (LTP) and long-term depression (LTD) represent two forms of synaptic plasticity which have been widely studied by electrophysiological techniques. However, the molecular mechanisms at target gene involved in the generation of long term depression remain to be determined. To elucidate the molecular mechanism underlying activity dependent synaptic remodeling in striatal long term depression, we used the mRNA differential display technology to isolate genes that are induced or modulated by high frequency stimulation of the corticostriatal pathway in a rat brain slice preparation. We have differentially displayed, by means of reverse transcriptase-polymerase chain reaction, mRNA species isolated from striatal slices in which long term depression was induced by tetanic stimuli as well as from slices stimulated at low frequency. We then compared radio-labeled RT-PCR banding patterns to isolate cDNAs that are differentially expressed. Three independent cDNAs were isolated and identified whose mRNA level were enhanced by tetanic stimulation inducing long term depression. We provide evidence that two of these genes encode proteins involved in synaptic vesicle trafficking (dynamin I and amphiphysin II). Moreover, expression of tissue plasminogen activator (t-PA) gene was also increased following striatal long term depression. Our data suggest that a complex pattern of genes acting at presynaptic level and extracellularly may be involved in LTD-associated synaptic remodeling.

Animals↗

PubMed1999

Treatment of supratentorial glioblastoma multiforme with radiotherapy and a combination of BCNU and tamoxifen: a phase II study.

From May 1990 to November 1994, 70 consecutive patients suffering from glioblastoma multiforme were treated following surgery with conventional radiotherapy and adjuvant IV BCNU administered alone or in combination with tamoxifen. Twenty-five patients received BCNU alone (control group A) while 24 patients also received 40 mg of tamoxifen (TMX) PO daily (group B) and 21 received 100 mg of TMX PO daily (group C). There were no significant differences between the 3 groups concerning age, type of resection and median post-operative Karnofsky performance status (KPS). Blood toxicity over grade II occurred in 33.5% of patients receiving TMX versus 12% of patients treated with BCNU alone (p < 0.05). Deep venous thrombosis complications were observed in 4 patients of each TMX group, whereas they were not observed in the control group (p < 0.04). Median time to tumor progression (MTTP) was 35 weeks in the control group and 27 weeks in both TMX groups B and C. Median survival time (MST) was 56, 66 and 51 weeks, respectively. These results suggest that the addition of TMX to standard treatment of glioblastomas does not affect the time to tumor progression and overall survival but may increase the risk of deep venous thrombosis or nitrosourea-induced blood toxicity.

Adult↗

PubMed1999

The equine herpesvirus 2 E1 open reading frame encodes a functional chemokine receptor.

Several herpesviruses contain open reading frames (ORFs) that encode potential homologs of eucaryotic genes. Equine herpesvirus 2 (EHV-2) is a gammaherpesvirus related to other lymphotropic herpesviruses such as herpesvirus saimiri and Epstein-Barr virus. The E1 ORF of EHV-2, a G protein-coupled receptor homolog, shows 31 to 47% amino acid identity with known CC chemokine receptors. To investigate whether E1 may encode a functional receptor, we cloned the E1 ORF and expressed it in stably transfected cell lines. We report here the identification of the CC chemokine eotaxin as a functional ligand for the EHV-2 E1 receptor. Chemokines are likely to play a role in the regulation of immune functions in equine hosts during EHV-2 infection and, via interaction with E1, may affect viral replication and/or escape from immune responses.

Amino Acid Sequence↗

PubMed1999

Paracrine regulation of insulin-like growth factor I (IGF-I) an IGF-II on prostaglandins F2alpha and E2 synthesis by human corpus luteum in vitro: a possible balance of luteotropic and luteolytic effects.

The existence of a complete intraovarian insulin-like growth factor (IGF) system replete with ligands, receptors, and binding proteins has been demonstrated as well as the ability of IGF-I to positively affect steroidogenesis in human granulosa cells. Furthermore, we recently showed that IGF-I and IGF-II stimulate progesterone secretion by human luteal cells. As the PGs, PGE2 and PGF2alpha, are classically known to have luteotropic and luteolytic effects, we wanted to determine whether the IGFs could affect the human luteal phase by influencing the PG system. For this reason, human luteal cells were cultured for different times (12, 24, and 48 h) with IGF-I, IGF-II (10-100 ng/mL), and GH (100 ng/mL), and both PGs were assayed in the medium culture. We found that both IGF-I and IGF-II were able to stimulate PGE2 synthesis in a time- and dose-dependent way, whereas they both inhibited PGF2alpha production. GH, too, significantly reduced PGF2alpha synthesis; this effect was IGF-I mediated because it was reverted by increasing dilutions of an anti-IGF-I antibody. On the contrary, no GH effect was observed on PGE2 production. In conclusion, based on these data and on our previous results, we speculate that IGFs could influence luteal steroidogenesis through PG system.

Adult↗

PubMed1998

The viral chemokine macrophage inflammatory protein-II is a selective Th2 chemoattractant.

Kaposi's sarcoma (KS) lesions are characterized by a prominent leukocyte infiltrate composed of mononuclear phagocytes and T cells. KS-associated CD4(+) and CD8(+) cells showed predominantly a type II cytokine profile. The CC chemokine viral macrophage inflammatory protein-II (vMIP-II) encoded by the KS-associated herpes virus 8 was a selective chemoattractant for T helper 2 (Th2 cells) and for monocytes, whereas it was inactive on other leukocytes, including Th1 cells, dendritic cells, and natural killer (NK) cells. vMIP-II was an agonist for CCR8, a chemokine receptor selectively expressed on CD4(+) and CD8(+) cells with a type II cytokine profile. Hence, vMIP-II has agonist activity for a chemokine receptor (CCR8), which is preferentially expressed on polarized Th2 cells. The capacity of vMIP-II to attract type II T cells selectively is likely to be a component of the virus strategy to subvert the host immune response.

Cell Movement↗

PubMed1998

The chemokine receptor CCR8 is preferentially expressed in Th2 but not Th1 cells.

In this paper we report on the cloning and characterization of mouse CCR8. Like its human homologue, it is predominantly expressed in the thymus. In the periphery, murine CCR8 mRNA was found most abundantly expressed in activated Th2-polarized cells and in NK1.1+ CD4+ T cells. Human CCR8 is also preferentially expressed in human Th2-polarized cells and clones. This pattern of expression suggests that CCR8 is part of a Th2-specific gene expression program. The CCR8 ligands I-309 and its mouse homologue T cell activation gene 3 (TCA-3) are potent chemoattractants for Th2-polarized cells. Taken together, these observations strongly suggest that CCR8 plays a role in the control of Th2 responses, and may represent a potential target for treatment of allergic diseases.

Amino Acid Sequence↗

PubMed1998

Prevalence of papillomavirus, Epstein-Barr virus, cytomegalovirus, and herpes simplex virus type 2 in urinary bladder cancer.

Recent epidemiological studies suggest that the risk for urological malignancies may be related to the exposure to infectious agents. Human Papillomaviruses type 16 and 18 (HPV 16, HPV 18), Epstein-Barr virus (EBV), cytomegalovirus (CMV) and herpes simplex virus type 2 (HSV-2) have been suggested previously as cofactors in the pathogenesis of some malignancies in humans. The present paper, the presence of HPV 16, HPV 18, EBV, CMV and HSV-2 genomes was investigated in a panel of 35 biopsies from urinary bladder carcinomas using the polymerase chain reaction (PCR). Sequences of EBV, HPV, CMV and HSV-2 genomes were detected in 34%, 31%, 11% and 9% of tissue samples respectively, while in 20% of patients we found more than one viral infection. Absence of viral genomes was found in normal bladder. To our knowledge, this is the first report concerning the association of EBV, CMV and HSV-2 with bladder cancer. This finding may raise the question whether such viral infection may contribute to development and progression of some types of urological malignancies in humans.

Adult↗

PubMed1998

Identification of the CC chemokines TARC and macrophage inflammatory protein-1 beta as novel functional ligands for the CCR8 receptor.

Chemokines are key molecules in directing leukocyte migration toward sites of inflammation. We have previously cloned a putative CC chemokine receptor gene, TER1, whose expression is restricted to lymphoid tissues and cell lines. Recently, this receptor has been shown to signal in response to the human CC chemokine I-309 and thus it has been renamed CCR8 according to the current nomenclature. In the present study, we report the identification of the CC chemokines thymus and activation-regulated cytokine (TARC) and macrophage inflammatory protein-1 beta (MIP-1 beta) as CCR8 ligands, as they induce chemotaxis in CCR8 Jurkat stable transfectants. Furthermore, we have generated a polyclonal antiserum that is able to recognize the CCR8 molecule in transfectant lysates. The pattern of CCR8 mRNA expression and the functional effects exerted by its ligand suggest that the triggering of this receptor may regulate multiple functions including activation, migration and proliferation of lymphoid cells.

Cell Line↗

PubMed1998

Neurological complications of radiotherapy and chemotherapy.

Neurological complications of radiotherapy and chemotherapy can affect the central or peripheral nervous system. Most are dose-dependent and constitute a limiting factor in the administration of treatments. Radiation-induced neurological complications are classified as acute, early-delayed or delayed. The most important are radionecrosis and cognitive dysfunction/leukoencephalopathy. Neurotoxicity of chemotherapy is frequent and depends upon dose, type of drugs (especially cisplatin and methotrexate) and their combination with radiotherapy.

Antineoplastic Agents↗

PubMed1998

High levels of transforming growth factor-alpha (TGF-alpha) mRNA may predict local relapses in early stage urinary bladder cancer.

Elevated expression of transforming growth factor-alpha (TGF-alpha) gene has been previously reported in some types of human neoplasms, but its role in the pathogenesis of bladder cancer has still not been investigated. In the present study, we analysed 28 samples of early stage bladder tumours for the presence of TGF-alpha mRNA using reverse transcription-polymerase chain reaction (RT-PCR). We detected TGF-alpha mRNA in 71% (20/28) of these samples. When we related the expression levels of TGF-alpha with local relapses of patients during a follow-up of 2 years, we found that a high TGF-alpha expression level in bladder cancer was significantly associated with local relapses in patients with early stage tumours. The appearance of early relapses in tumours with high TGF-alpha expression levels may suggest the existence of an additional marker in the prediction of local relapses in patients with superficial disease.

Adult↗

PubMed1998

Endothelin-1 inhibits basal and human chorionic gonadotrophin-stimulated progesterone production.

Endothelin-1 (ET-1) is a peptide classically produced by endothelial cells and known for its powerful vasoconstrictor activity. However, recent data suggest an involvement of ET-1 also in reproductive function. This study was designed to examine the possible presence and role of ET-1 in human luteal cells. Purified luteal cells were incubated for different times with ET-1 (10(-9)-10(-6) M) or ET-3 (10(-9)-10(-6)) alone or associated with human chorionic gonadotrophin (HCG) (100 ng/ml). Both basal and HCG-induced progesterone production were significantly reduced by ET-1 at all examined times whereas preincubation of luteal cells with BQ485 (10(-9)-10(-6) M), an ET-A receptor antagonist, prevented the inhibitory effect of ET-1. Conversely, no effect on progesterone synthesis was observed when ET-3 was added to the cultures. Luteal cells were then incubated for 24 h with phorbol 12-myristate-13 acetate (PMA) (100 ng/ml), an activator of protein kinase C. Inhibition of progesterone synthesis by PMA was similar to that induced by ET-1 alone. This study demonstrates that ET-1 negatively affects, at physiological concentrations, basal and HCG-induced progesterone synthesis. These effects seem to be exerted through the ET-A receptors and the protein kinase C pathway. Conversely, ET-3 was not able to influence human luteal steroidogenesis.

Cells, Cultured↗