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M De Falco

Publications and source records attributed to M De Falco.

At least 37 records · Page 2Linked to original sources
PubMed2001

Expression of the retinoblastoma-related p107 and Rb2/p130 genes in human placenta: an immunohistochemical study.

It has been proposed that tumor suppressor genes may have a role in the mechanisms of proliferation and differentiation during human placental development. The Retinoblastoma gene family is a well known family of tumor suppressor genes. Many studies have pointed out a role of this family not only in cell cycle progression, but also during development and differentiation. On the light of these observations we have investigated the immunohistochemical expression pattern of the Retinoblastoma family members, p107 and Rb2/p130 in human placenta samples in first trimester and full-term placental sections. p107 and pRb2/p130 showed the most abundant expression levels during the first trimester of gestation and progressively declined to being barely detectable in the placenta by late gestation. These results indicate that the expression of the above genes is modulated during placental development and suggest a mechanism for controlling trophoblast proliferation.

Adult↗
PubMed2001

[Primary lymphoma of the gastrointestinal tract].

BACKGROUND: A retrospective analysis of 12 years' experience (1987-1999), concerning gastro-intestinal lymphomas (LNH-GI) has been performed, to offer a contribution for the identification of the diagnostic and prognostic criteria. METHODS: During this period, 11 cases (9 male and 2 female) have been treated: 8 with gastric localization and 3 with intestinal localization, with age ranging between 12 and 78 years. Most of the analyzed cases (5 cases out of 8 with gastric localization and all the cases with intestinal localization) underwent surgical treatment without a sure understanding of the nature of lymphoma. Clinical observation showed forms in an advanced state of local development. RESULTS: However, the low specifity of available diagnostic tools and the therapeutic delay are factors that seems do not influence the prognosis, as well as the stage of the disease determined with traditional classification methods. The aspect that seems to be crucial for the prognosis of the disease is the histotype (5 low grade cases free of desease from 36 months to 10 years, vs 4 high grade cases died between 46 days and 40 months after the surgical treatment). CONCLUSIONS: Some interesting considerations arise from the analysis of the diagnostic procedure and from the method of treatment: the specifity and precocity of the diagnosis could be improved by a large use of endoscopic ultrasonography that allow to obtain deep biopsy; the identification of histotype before surgical treatment can address and modulate the therapeutic strategy eliminating the over treatment for L.G. forms.

Adolescent↗
PubMed2001

[Differentiated thyroid carcinoma. Prognosis and therapy].

BACKGROUND: We have conducted retrospective analysis of 90 cases of Differentiated Thyroid Cancer (DTC) operated between 1978 and 1998. The aim of this study was to verify the most widely used prognostic factors and to try to identify differences in the development of these tumors. METHODS: The DTCs, selected from the histopathologic reports of the Institute of Pathologic Anatomy, were divided into high, intermediate and low malignancy tumors according to the classification of Carcangiu and Rosai. RESULTS: We found that age >45 years associated with a cancer larger than 1.5 cm and intermediate malignancy was related to the most dismal prognosis. Ten of the 90 cases had a dismal prognosis; 6/10 (60%) had disease recurrence. Four of those six patients died; one has disease recurrence 5 months after surgery, and one patient with disease recurrence after one year was lost to follow-up. The identification of metastases at the primary operation is of course an unfavourable prognostic factor. In fact, all of the six cases with metastases had disease recurrence after the treatment: three patients have died; two survive (one have a disease period of 5 months and the other a disease period of 2 years); one patient with disease recurrence one year after surgery was lost to follow-up. CONCLUSIONS: The most significant negative factors for prognosis purposes were the higher degrees of T, the presence of metastases at diagnosis or their appearance at follow-up, age greater than 45, male sex and areas of dedifferentiation within the histological pattern. Total thyroidectomy remains the treatment of choice.

Adult↗
PubMed2001

[Efficacy of somatostatin analogs in the treatment of neuroendocrine tumours and paraneoplastic syndromes].

BACKGROUND: The authors report their experience with octreotide LAR in the adjuvant treatment of 10 patients suffering from neuroendocrine tumours and paraneoplastic syndromes. METHODS: All patients were studied preoperatively using traditional radiology and scintigraphy using octreoscan. RESULTS: Octreoscan was positive in all cases for somatostatin receptors. All patients with neuroendocrine tumours underwent surgery of the primary neoplasm; treatment with somatostatin was commenced at a later stage. CONCLUSIONS: The authors' experience with octreotide LAR proved to be an efficacious means of controlling symptoms and stabilising disease without collateral effects. They conclude by affirming that octreotide LAR represents a valid therapeutic choice in the symptomatic treatment of neuroendocrine tumours.

Aged↗
PubMed2001

[Carotid glomus tumours. Personal experience in the surgical treatment of chemodectoma].

The authors present 6 cases of carotid glomus tumours referred to their attention over the past 10 years. Their experience shows that colour ultrasonography (using both morphological and functional evaluation) is the diagnostic key for defining the treatment of paraganglioma. More recent experience highlights the role of 111In Pentreotride using a multidisciplinary therapeutic approach.

Adult↗
PubMed2000

Homocysteinaemia during pregnancy and placental disease.

OBJECTIVE: Hyperhomocysteinaemia, due to enzymatic defects or to the lack of some vitamin cofactors (vit. B6, vit. B12, folic acid), could be associated with obstetric disease. The aim of this study was to investigate placental disease in women with mild-moderate hyperhomocysteinaemia. MATERIALS AND METHODS: Blood samples of seven pregnant women with severe early onset preeclampsia were assessed for hyperhomocysteinaemia. The obtained values were compared with those of a control group. In all cases, tissue samples obtained from the placenta, umbilical cord and membranes were studied. One of the patients was treated empirically with folic acid during a subsequent pregnancy. RESULTS: Patient homocysteine plasma levels were higher than in the control group. In all cases several placental abnormalities were found. The patient treated with folic acid had a good pregnancy outcome. CONCLUSION: Hyperhomocysteinaemia during pregnancy could be responsible for placental abnormalities. Treatment with folic acid could improve pregnancy outcome in women with homocysteine metabolism abnormalities.

Adult↗
PubMed1999

Kelletinin A, from the marine mollusc Buccinulum corneum, promotes differentiation in Hydra vulgaris.

The effects of kelletinin A [ribityl pentakis (p-hydroxybenzoate)] (KA), a natural compound isolated from the marine gastropod Buccinulum corneum, were studied in vivo in Hydra vulgaris during regeneration. KA caused a marked increase of regenerated tentacle numbers (ATN) and promoted transdifferentiation of epithelial cells into battery cells, and nematocyte differentiation. Morphological data were correlated to changes in acid and alkaline phosphatase levels, enzymes that have been described as regeneration markers.

Acid Phosphatase↗
PubMed1998

Multiple forms of DNA polymerase from the thermo-acidophilic eubacterium Bacillus acidocaldarius: purification, biochemical characterization and possible biological role.

Two DNA polymerase isoenzymes, called DpA and DpB on the basis of their elution order from DEAE cellulose, were purified to homogeneity from the thermo-acidophilic eubacterium Bacillus acidocaldarius. The enzymes are weakly acidophilic proteins constituted by a single subunit of 117 and 103 kDa respectively. DpA and DpB differ in thermostability, in thermophilicity, in sensitivity to assay conditions and in resistance to sulphydryl-group blocking agents such as N-ethylmaleimide and p-hydroxymercuriobenzoate. They differ also in synthetic template-primer utilization, in the apparent Km for dNTPs and in processivity. In particular, DpA utilizes more effic iently synthetic templates-primers such as poly(dA).poly(dT), poly(dT). (rA)12-18 and poly(rA).(dT)12-18 and presents a greater tendency to accept dNTP analogues modified in the sugar or in the base ring, such as cytosine beta-d-arabinofuranoside 5'-triphosphate, 2',3'-dideoxyribonucleosides 5'-triphosphate, butylphenyl-dGTP and digoxigenin-conjugated dUTP. In addition, DpA presents an exonuclease activity that preferentially hydrolyses DNA in the 5'-3' direction, whereas DpB lacks this activity. The possible biological role of the enzymes is discussed.

Bacillus↗
PubMed1996

Inhibition mechanisms of HIV-1, Mo-MuLV and AMV reverse transcriptases by Kelletinin A from Buccinulum corneum.

Kelletinin A [ribity pentakis (p-hydroxybenzoate)] (KA), an inhibitor of HTLV-1 replication isolated from Buccinulum corneum, showed a noncompetitive inhibitory activity with respect to the template primer and to dTTP in the poly(rA).oligo(dT)12-18-directed reaction of HIV-1, Mo-MuLV and AMV reverse transcriptases (RT). Analysis of natural and synthetic KA-related compounds showed that the inhibitory activity was strictly related to the structural peculiarities of the molecule. In the presence of DNA as template primer the inhibition mechanism was drastically modified: HIV-1 RT activity was stimulated by low concentrations of KA and was inhibited by increasing the concentration of the compound, while Mo-MuLV and AMV activities were irreversibly inhibited by the formation of a non-reactive complex. The RNase H activities of these RTs were not affected by KA. The results of this study suggest a different mechanism of interaction of Kelletinins with HIV-1 RT compared with other non-nucleoside inhibitors. A possible use of these drugs in combination therapy and in the design of structure-based reverse transcriptase inhibitors is discussed.

Animals↗
PubMed1988

A turbidometric assay for measuring proteins in culture media.

An immunoturbidometric assay was developed for the measurement of proteins in culture fluids of hepatocytes. The assay is simple to perform and avoids the biohazards associated with radioimmunoassays. The limit of detection of this assay exemplified by hemopexin and transferrin is 5 ng/ml protein. This degree of sensitivity is attained by incorporating into the procedure the addition of polyethylene glycol to enhance formation of primary antigen-antibody complexes and of a second antibody to further increase the immune complex size, which favors the ratio of specific to background light scattering.

Animals↗
PubMed1988

Peptide-specific antibodies employed in determining the interspecies immunological cross-reactivity of haemopexin.

1. Antibodies were raised in rabbits against nine peptides analogous to sequences of the human serum beta-glycoprotein haemopexin, and seven peptides were very antigenic. 2. One of these affinity-purified peptide-specific antibodies interacted with a highly conserved sequence of the haemopexin of five of the seven species tested. 3. Another antibody bound pig haemopexin even better than human haemopexin. 4. The overall, arbitrarily assessed, immunological cross-reactivity between the haemopexin of human and other species follows the order: rabbit greater than mouse greater than chicken greater than pig greater than rat greater than cow.

Animals↗
PubMed1986

An avian serum alpha 1-glycoprotein, hemopexin, differing significantly in both amino acid and carbohydrate composition from mammalian (beta-glycoprotein) counterparts.

We report here on physicochemical characteristics of chicken hemopexin, which can be isolated by heme-agarose affinity chromatography [Tsutsui, K., & Mueller, G. C. (1982) J. Biol. Chem. 257, 3925-3931], in comparison with representative mammalian hemopexins of rat, rabbit, and human. The avian polypeptide chain appears to be slightly longer (52 kDa) than the human, rat, or rabbit forms (49 kDa), and also the glycoprotein differs from the mammalian hemopexins in being an alpha 1-glycoprotein instead of a beta 1-glycoprotein. This distinct electrophoretic mobility probably arises from significant differences in the amino acid composition of the chicken form, which, although lower in serine and particularly in lysine, has a much higher glutamine/glutamate and arginine content, and also a higher proline, glycine, and histidine content, than the mammalian hemopexins. Compositional analyses and 125I concanavalin A and 125I wheat germ agglutinin binding suggest that chicken hemopexin has a mixture of three fucose-free N-linked bi- and triantennary oligosaccharides. In contrast, human hemopexin has five N-linked oligosaccharides and an additional O-linked glycan blocking the N-terminal threonine residue [Takahashi, N., Takahashi, Y., & Putnam, F. W. (1984) Proc. Natl. Acad. Sci. U.S.A. 81, 2021-2025], while the rabbit form has four N-linked oligosaccharides [Morgan, W. T., & Smith, A. (1984) J. Biol. Chem. 259, 12001-12006]. In keeping with the finding of a simpler carbohydrate structure, the avian hemopexin exhibits only a single band on polyacrylamide gel electrophoresis under both nondenaturing and denaturing conditions, whereas the hemopexins of the three mammalian species tested show several bands.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMedDate not supplied

Expression and distribution of notch protein members in human placenta throughout pregnancy.

Notch signaling is an evolutionarily conserved mechanism used by invertebrates and vertebrates to control cell fates through close-range cell interactions. Four Notch receptors have been identified in vertebrates and different ligands, divided into Delta-like and Serrate-like (Jagged). Several studies have demonstrated that Notch signaling is involved in different branches of the cell fate decision tree: differentiation, proliferation and apoptosis. These three processes are finely regulated in human placenta in order to allow a successful pregnancy and a correct fetal growth. Moreover, Notch and its ligands participate in the vascular remodelling and stabilization, other two processes much important and ticklish in human placenta. So, we decided to investigate the pattern of expression of Notch-1, Notch-4 and Jagged-1, together with two members related to Notch pathway and involved in angiogenesis: VEGF and p21, in human placenta during gestation by immunoblotting and immunohistochemistry. We showed a modulation of Notch proteins throughout the pregnancy; in particular we showed a slight decrease of Notch-1 throughout pregnancy, with a decreased cytoplasmic staining from the first to the third trimester of gestation in cytotrophoblast and syncytiotrophoblast. In contrast Jagged-1 showed an increase throughout pregnancy especially in syncytiotrophoblast and stroma during the third trimester of gestation. In addition, we found by immunoblotting an increase of VEGF expression from the first to the third trimester and an intense VEGF expression inside endothelial cells throughout the gestation as also confirmed by immunohistochemistry. We also showed a decrease of p21 expression during the pregnancy both through immunoblotting and immunohistochemistry assays. Moreover, we observed Notch localization in extravillous trophoblast cells that are able to invade the decidualized endometrium. Our results suggest an involvement of Notch signaling in regulation of placental cell fate decision and in angiogenesis that are dramatically important to maintain a normal physiology of this organ during pregnancy.

Calcium-Binding Proteins↗
PubMedDate not supplied

Vasoactive intestinal peptide stimulation modulates the expression of Bcl-2 family members in the adrenal gland of the lizard Podarcis sicula.

The adrenal gland of the lizard Podarcis sicula is formed by a dorsal ribbon of chromaffin cells, generally defined as medullary tissue, arranged along a central part of steroidogenic cells considered as cortical tissue. These two tissues produce catecholamines and steroids as part of the hypothalamo-hypophyseal-adrenal gland axis. Recent studies have demonstrated that Podarcis sicula adrenal gland is not only under hypothalamo-hypophyseal axis control but that several peptides may influence the physiological activity of the gland; among these, vasoactive intestinal peptide is able to enhance strongly both catecholamine and steroid hormone production. The aim of the present study was to verify whether vasoactive intestinal peptide administration could become deleterious. For this reason, we monitored the pattern of expression of two members of the Bcl-2 family, Bcl-2 and Bax, in control and vasoactive intestinal peptide treated specimens. Furthermore, we also tested if peptide treatment induces apoptosis by TUNEL assay.

Adrenal Glands↗
PubMedDate not supplied

[Total implantable venous systems in day surgery].

UNLABELLED: Total implantable venous system (port-cath)in day surgery. AIMS: Most of patients underwent to a total implantable venous system (port-cath) can be treated in day surgery. METHODS: Since January 2000 to March 2003 we have implanted 31 port-a-cath, preferring access in subclavia v. We've treated all patients in day surgery and we've performed a Rx-control with a medium follow up of two hour. RESULTS: We have not reported any early complication, only 3 late complications: a device malfunction, a "kinking" reservoir and an infection of the subcutaneous pocket. The last two complications have required the explantation of the device. In difficult catheterizations can be helpful to use a pediatric kit. The rules of an aseptic and antiseptic operative procedure and the utilization of a short term antibiotic prophylaxis can avoid infective complications. We have proposed, after the device implantation, cardioaspirina like preventive therapy of septic and no septic thrombosis. In the thrombotic occlusion of the catheter we propose the use of activase. In malfunction's prevention we propose a lateral placement (to the skin incision) of the subcutaneous pocket and a 45 degrees reservoir rotation. CONCLUSIONS: The total venous system (port-cath) implantation can be mostly performed in day surgery, improving the compliance of the patients with a low cost procedure.

Ambulatory Surgical Procedures↗
PubMedDate not supplied

[Interstitial laser photocoagulation in liver tumours: our experience].

Interstitial lasertherapy (ILT) is one of the percutaneous thermal procedures allowing the ablation of primary or secondary hepatic lesions. This technique can be performed without general anaesthesia, since the patient is completely painless, in spite of the high temperatures reached, because there are no sensitive fibers around the lesion. This study includes patients with small hepatocarcinomas (< 2 cm) non peripherically sited, far from the gallbladder and the hepatic hilum. Twenty patients suffering from 24 cirrhotic hepatocarcinomas (two patients showed two nodules) have been enrolled for the present study. Mean diameter of lesions was 1.8 cm (1.3-2 cm). One or more 21 G (length 20 cm) Chiba's needles were inserted under sonographic view into the lesions. The laser energy was switched on at 4 Watts for 4-6 minutes, until an amount of energy of 900-1800 Joule was reached. All the patients were discharged 48 hours after the procedure. Triphasic CT-scan with contrast were performed 7 to 14 days after ILT, in order to check its efficacy. CT-scan showed complete necrosis in all the nodules ranging from 1.5 to 3 cm. All the patients received only one IL T session, whose longest duration was 20 minutes. No major complications occurred. ILT of small hepatocarcinomas is a safe, efficient procedure, also feasible without anaesthesia. Differently from percutaneous radiofrequency, in fact, it shows the advantage of less pain, that can avoid the need for general anaesthesia.

Aged↗