Biomedical subjects

A Pucci

Publications and source records attributed to A Pucci.

At least 19 recordsLinked to original sources

PubMed2006

Stent graft in TIPS: technical and procedural aspects.

Transjugular intrahepatic portosystemic shunt (TIPS) is a nonoperative therapeutic option for the management of portal hypertension, variceal bleeding, recurrent ascites, Budd-Chiari syndrome. In view of the many issues surrounding the use of TIPS, in 1994 the US National Digestive Diseases Advisory Board convened a scientific conference to review the current data available and to establish the indications and controindications for this procedure. However there are still unsolved problems especially short primary patency of the shunt due to intimal hyperplasia, which causes a reduction of the shunt lumen thus favoring a return of the portal hypertension with recurrent variceal bleeding. Several study were performed in the last years to evaluate the efficacy of covered stent in order to reduce shunt disfunction secondary to intimal hyperplasia. PTFE seems to be more efficient in the prevention of restenoses. In our experience more then 100 patients were treated with the Viatorr stent-graft. After a follow-up ranging from 1 to 50 months we reported a 1- year primary patency rate of 83.8%. However the use of the stentgraft is correlate with a high rate of hepatic hencefalopathy (46.6 %). In case of hepatic hencefalopathy refractory to the conventional medical therapy, TIPS reduction should be performed.

Ascites↗

PubMed2006

Infrared reflection-absorption spectra of C2H4 and C2H6 on Cu: effect of surface roughness.

Infrared reflection absorption spectroscopy (IRRAS) of the highly symmetric molecules C2H4 and C2H6 adsorbed as mono- and multilayers onto copper films is studied in relation to the type of metal-film roughness. Spectra of C2H4 show Raman lines on cold-deposited Cu films but not on Cu deposited at room temperature. For C2H6, the IR spectra from both types of metal films are similar; the surface infrared selection rule holds and no Raman bands are observed. The Raman lines that appear in the IR spectra already at low exposures are attributed to species adsorbed at special defect sites, identical to the so-called active sites in surface enhanced Raman scattering (SERS). The IR excitation mechanism by transient electron transfer to the adsorbate pi* state can deliver a discrete vibrational band of a Raman-active vibration only under certain circumstances, for example, for adsorbates at the "SERS-active sites". C2H6 at these sites cannot deliver Raman bands in IRRAS, because it has no pi* state. We also discuss IRRAS measurements on Cu(111) and Cu(110) single crystals, where Raman bands of C2H4 have been observed.

Journal Article↗

PubMed2006

Relationship between preclinical abnormalities of global and regional left ventricular function and insulin resistance in severe obesity: a Color Doppler Imaging Study.

BACKGROUND: The aim of this study was to evaluate the relationship between insulin resistance and preclinical abnormalities of the left ventricular structure and function detected in severe obesity by Color Doppler Myocardial Imaging (CDMI). Forty-eight consecutive severely obese patients (Group O) (11 males, 37 females, mean age 32.8+/-7 years) were enrolled. Forty-eight sex- and age-matched non-obese healthy subjects were also recruited as controls (Group C). All subjects underwent conventional 2D-Color Doppler echocardiography and CDMI. The homeostasis model assessment insulin resistance index (HOMA-IR) was used to assess insulin resistance results. Obese subjects had a greater left ventricular mass index (by height) (58.8+/-14 g/m(2.7)) than controls (37+/-8 g/m(2.7)) (P<0.0001), owing to compensation response to volume overload caused by a greater cardiac output (P<0.02). Preload reserve was increased in obese subjects, as demonstrated by a significant increase in left atrial dimension (P<0.0001). Obese patients had a slightly reduced LV diastolic function (transmitral E/A ratio: Group O, 1.1+/-0.8 vs Group C, 1.5 +/-0.5; P<0.002). Cardiac deformation assessed by regional myocardial systolic strain and strain rate (SR) values was significantly lower (abnormal) in obese patients than in controls, both at the septum and lateral wall level. These strain and SR abnormalities were significantly related to body mass index. In addition, the early phase of diastolic function, evaluated using SR, was compromised in obese patients (P<0.001). The HOMA-IR values in obese patients were significantly higher (3.09+/-1.6) than those determined in the control group (0.92+/-0.5) (P<0.0001). The HOMA-IR values, in the obese group, were significantly related to systolic strain and SR values sampled at the septum level (P<0.0001). CONCLUSION: In conclusion, this study has demonstrated that obese patients pointed out systolic structural and functional abnormalities at a preclinical stage, in particular through strain and SR analysis; on the other hand, those altered CDMI parameters well distinguish obese subjects as compared with the control group. Furthermore, another main finding of the study was that myocardial deformation (systolic strain) could have a correlation with insulin resistance level.

Adult↗

PubMed2006

Oral manifestations of langerhans cell histiocytosis in a pediatric population: a clinical and histological study of 8 patients.

Langerhans Cell Histiocytosis is a rare and protean disease of unknown etiology, clinically characterized by single or multiple osteolytic and/or soft tissue lesions. Oral involvement may predate systemic manifestations or mimic infectious/inflammatory disorders. In the present series, oral involvement characterized eight cases of pediatric Langerhans Cell Histiocytosis and oral symptoms represented a very early sign of this disease in four patients. A careful clinical investigation and a proper histologic analysis were required for achieving a definite diagnosis and for confirming clinical suspicion of disease relapse. Immunohistochemistry, that nowadays represents a reliable and accessible ancillary histological technique, allowed the definite diagnosis in all cases of our series.

Child, Preschool↗

PubMed2006

Familial tumoral calcinosis and testicular microlithiasis associated with a new mutation of GALNT3 in a white family.

BACKGROUND: Familial tumoral calcinosis (FTC) is a rare autosomal recessive disease characterised by the development of multiple calcified masses in periarticular soft tissues; GALNT3 gene mutations have recently been described in an African American and in a Druse Arab family with FTC. OBJECTIVE: To report the clinical and histological features caused by a new GALNT3 mutation in a white family. RESULTS: Homozygosity for the nonsense mutation Lys463X was found in both affected siblings, who displayed a classic phenotype, the male also having testicular microlithiasis. He is the first subject described with testicular microlithiasis in FTC. CONCLUSIONS: The high testicular expression of GALNT3 suggests that the gene alteration could act locally by causing deposition of calcium, and the testis may be an underestimated site of calcification in FTC. Autoimmune diseases are present in several members of the family. Although immune disorders have been described in FTC, autoimmunity does not segregate with the GALNT3 mutation in this family.

Autoimmune Diseases↗

PubMed2003

Inhibition of interleukin-12 expression by alpha-thrombin in human peripheral blood mononuclear cells: a potential mechanism for modulating Th1/Th2 responses.

In addition to its central role in blood coagulation and hemostasis, human alpha-thrombin is a powerful regulator of inflammatory responses and is known to affect cell-mediated immunity. Interleukin (IL)-12 is a strong promoter of the development of Th1-type lymphocytes and its downregulation implies a positive feedback mechanism for development of Th2 responses. We have previously shown that thrombin enhances the release of IL-6, a Th2-related cytokine, in human peripheral blood mononuclear cells (PBMC). Here we show that thrombin downregulates IL-12 production at both protein and mRNA levels in human PBMC. The inhibition of IL-12 production was accompanied by an enhanced release of IL-10, which inhibits Th1-related processes and promotes Th2-type responses. The use of proteolytically inactive thrombin and of the specific thrombin receptor agonist peptide, SFLLRN, reveals that this downregulation is thrombin-specific and requires thrombin proteolytic activity. In addition, activation of coagulation inhibits IL-12 production in whole blood cultures, confirming the tight relationship between the coagulation pathway, where thrombin is a key enzyme, and inflammation. Decreased IL-12 production appears to be related also to IL-10 production, since the addition of an anti-IL-10 monoclonal antibody to thrombin-treated PBMC resulted in a partial restoration of IL-12 production. In conclusion, the observation that thrombin significantly affects the production of IL-12, as well as of IL-10, implies a concerted role orchestrated by thrombin in PBMC that could be crucial to effective immunity and inflammation.

Gene Expression Regulation↗

PubMed2003

Regulation of angiogenesis by Th1- and Th2-type cytokines.

Angiogenesis is a complex process, where several cell types and mediators interact to establish a specific microenvironment suitable for the formation of new capillaries from pre-existing vessels. Such biological processes occur in several physiological conditions, such as embryo development and wound healing, as well as in pathological conditions, including tumours and diabetic retinopathy. T lymphocytes, neutrophils and monocytes fully participate in the angiogenic process by secreting cytokines that may control endothelial cell (EC) proliferation, their survival and apoptosis, as well as their migration and activation. Angiogenesis is the result of a net balance between the activities exerted by positive and negative regulators. This balance is conceptually very similar to that of the Th1/Th2 cells that modulate an appropriate and specific immune response. Th1 or Th2 cytokines may control angiogenesis directly, by acting on cell growth and differentiation, indirectly by inducing the release of other cytokines in the microenvironment, and by modulating the expression of specific receptors, involved in the control of angiogenic processes, such as EC proliferation and migration. In this review we will mainly discuss the role of Th1- and Th2-type cytokines in the angiogenic process, emphasizing the complexity of the cytokine and leukocyte/EC network, and highlighting the care that needs to be taken when designing new therapeutic interventions involving Th1 and Th2 cytokines.

Cell Division↗

PubMed2001

Hypoxia induces the expression and release of interleukin 1 receptor antagonist in mitogen-activated mononuclear cells.

Hypoxia modulates the expression of inflammatory mediators in a variety of cell types. Since interleukin (IL-)1 receptor antagonist (Ra) is a cytokine widely associated with an inflammatory state and is expressed by activated mononuclear cells, we investigated whether hypoxia induces IL-1Ra expression in human peripheral blood mononuclear cells (PBMC) activated by phytohaemagglutinin (PHA). RNase protection assay, conducted on PHA-activated PBMC cultured under hypoxic conditions (2% O(2)) for 16-40 h, revealed that hypoxia enhances IL-1Ra mRNA expression. Further, IL-1Ra release was significantly affected by hypoxia, as determined by ELISA. Concomitantly, hypoxia enhanced, even though at a lesser extent, both IL-1alpha and IL-1beta mRNA expression and release, as determined by RPA and ELISA. However, at 40 h of treatment, hypoxia did not affect cell viability and DNA fragmentation, but caused an inhibition of the proliferation index after PHA stimulation, obtained by MTT assay. These results suggest that activated mononuclear cells tend to respond to hypoxic stress by modulating the expression of IL-1Ra and IL-1-related molecules and their release in the surrounding microenvironment.

Apoptosis↗

PubMed2001

Identification of a human immunodominant B-cell epitope within the GRA1 antigen of Toxoplasma gondii by phage display of cDNA libraries.

Excreted secreted antigens of the protozoan parasite Toxoplasma gondii play a key role in stimulating the host immune system during acute and chronic infection. With the aim of identifying the immunodominant epitopes of T. gondii antigens involved in the human B-cell response against the parasite, we employed a novel immunological approach. A library of cDNA fragments from T. gondii tachyzoites was displayed as fusion proteins to the amino-terminus of lambda bacteriophage capsid protein D. The lambda D-tachyzoite library was then affinity-selected by using a panel of sera of pregnant women, all infected with the parasite. Some of the clones identified through this procedure matched the sequence of the dense granule GRA1 protein (p24), allowing us to identify its antigenic regions. In particular, the analysis of human antibody response against the recombinant GRA1 antigen fragments revealed the existence of an immunodominant epitope (epi-24 peptide).

Amino Acid Sequence↗

PubMed2001

Distribution of heavy metals in surface sediments from an Antarctic marine ecosystem.

The concentrations of lead, cadmium, copper, chromium, iron, manganese and zinc in surface sediments collected from Potter Cove, in the 25 de Mayo Island (King George Island), Antarctica, and its drainage basin, were measured by atomic absorption spectroscopy. The obtained results were use to determine the areal and vertical distribution of the metals of in the Cove and potential sources of these metals to this environment. The geochemical data suggest that most of the metals found in Potter Cove constitute a redistribution of autochthonous materials within the ecosystem. Therefore, the metal concentrations can be considered to be present at natural background levels in surface sediments.

Antarctic Regions↗

PubMed2001

ADAM-HCV, a new-concept diagnostic assay for antibodies to hepatitis C virus in serum.

We screened phage libraries using sera from noninfected individuals and patients infected by hepatitis C virus (HCV). By applying different selection and maturation strategies, we identified a wide collection of efficient phage-borne ligands for HCV-specific antibodies. The selected ligands retained their antigenic properties when expressed as multimeric synthetic peptides. Peptides that mimic several immunodominant epitopes of the virus were used to develop a novel type of diagnostic assay which efficiently detects antibodies to HCV in serum. This type of analysis provides a conclusive diagnosis for many patients identified as indeterminate according to presently available serological assays.

Amino Acid Sequence↗

PubMed2000

Neonatal and adult human heart tissues from normal subjects and patients with ischemic, dilated or hypertrophic cardiomyopathy express insulin-like growth factor binding protein-3 (IGFBP-3).

In the human fetus IGFBP-3 mRNA expression is most abundant in the skin, muscle and heart but circulating IGFBP-3 levels show age-related variations. In human heart tissues from controls and patients with either ischemic, dilated or hypertrophic cardiomyopathy (no.: 20, age-range from fetuses to elderly subjects) we determined the expression of cardiac IGFBP-3 mRNA by reverse transcriptase polymerase chain reaction (RT-PCR) and the protein by Western blotting. The same parameters were also determined in human livers. We detected IGFBP-3 mRNA in neonatal and adult as well as in fetal human heart tissues in both ventricles. Western blotting revealed the presence of IGFBP-3 in all the examined cardiac tissues. IGFBP-3 appeared to be more abundant in the heart than in the liver and in the failing hearts from patients with ischemic heart disease than in those with hypertrophic cardiomyopathy. Thus both normal and pathological human heart tissues express IGFBP-3 across lifespan and IGFBP-3 could play IGF-dependent and/or -independent actions at the myocardial level.

Adult↗

PubMed2000

Thrombin regulates the expression of proangiogenic cytokines via proteolytic activation of protease-activated receptor-1.

In addition to its central role in blood coagulation and hemostasis, human alpha-thrombin is a growth factor for a variety of cell types, including monocytes and endothelial cells, involved in the control of angiogenesis. Different cytokines produced by mononuclear cells have been implicated in angiogenic processes associated with tissue repair and certain human malignancies. We have previously shown that thrombin enhances proliferative responses in T lymphocytes. More recently, we reported that interferon-gamma-differentiated monocytes have increased expression of protease-activated receptor-1 (PAR-1) and increased thrombin binding. Since cytokines may be involved directly and indirectly in angiogenesis, we initiated studies to determine thrombin effects on the induction of cytokines, such as interleukin (IL)-1 and IL-6, in human mononuclear cells. IL-1 and IL-6 protein expression was significantly enhanced by thrombin (P<.05), as determined by enzyme-linked immunosorbent assay (ELISA). Treating mononuclear cells with the PAR-1 peptide, SFLLRN, has effects similar to those of thrombin. Thus, it appears that these thrombin effects are mediated through activation of PAR-1. These results confirm that thrombin is a strong activator of monocytes and could be involved in angiogenesis by inducing cytokines that could enhance the angiogenic process in tissue repair.

Cells, Cultured↗

PubMed2000

Histopathologic and clinical characterization of cardiac myxoma: review of 53 cases from a single institution.

BACKGROUND: Cardiac myxomas have varying clinical presentation, uncertain histogenesis, and debatable immunohistochemical profile. A few malignant cases have been previously reported. METHODS: Fifty-three consecutive cardiac myxomas were histologically investigated and results compared with clinical data. The main goal of the study was to investigate the immunohistochemical differentiation and the clinicopathologic correlations. RESULTS: Stromal cells were characterized by the expression of the von Willebrand factor endothelial marker (12 of 53 cases) and diffuse cytoplasmic neuropeptides such as protein gene product 9.5 (50 of 53 cases), S100 protein (47 of 53) and neuron-specific enolase (30 of 53), all of which were expressed in 30 (57%) of 53 tumors. Stromal cells did not show endocrine granules, epithelial, or smooth muscle immunoreactivity. Non-cardiac-related symptoms were observed in 7 of 53 patients and promptly disappeared after tumor excision; median values and percentages of total immunoreactivity scores for neuropeptides were higher in these 7 cases, but data analysis showed no statistical significance. Glands were detected in 2 myxomas, and they showed epithelial (cytokeratins and carcinoembryonic antigen), protein S100, and neuron-specific enolase immunoreactivity; this pattern has been previously detected in human gut. All tumors showed benign behavior, and no mitosis was detected. CONCLUSIONS: The results of this study support the hypothesis that stromal cells originate from multipotent mesenchyme capable of neural and endothelial differentiation; rare myxoma glands would represent entrapped foregut rests. A correlation could exist between neuroendocrine differentiation and non-cardiac-related symptoms.

Adult↗

PubMed1997

The use of epilithic Antarctic lichens (Usnea aurantiacoatra and U. antartica) to determine deposition patterns of heavy metals in the Shetland Islands, Antarctica.

Trace-metal contents were recorded for the epilithic antarctic lichens Usnea aurantiacoatra and U. antartica, sampled close to the Argentine scientific station 'Jubany' on '25 de Mayo' (King George) Island, in the Southern Shetland Archipelago (Antarctica). The corresponding heavy-metal levels have been measured through atomic absorption spectrophotometry, following internationally accepted analytical methods. The results obtained support the hypothesis that an atmospheric circulation of trace metals exists on the assessed area, and the activities developed at the different scientific stations located on this island would be a potential source of heavy metals to the evaluated environment. The geographical distribution of trace metals atmospherically transported in the area close to 'Jubany Station' was studied through the corresponding metal contents of the assessed lichens. Finally, the suitability of both analyzed lichen species, Usnea aurantiacoatra and U. antartica, as biological indicators for quantitative monitoring of airborne metals for this antarctic environment was recognized.

Air Pollutants↗

PubMed1997

Causes of late failure after heart transplantation: a ten-year survey.

BACKGROUND: Little is known about the causes of death of heart transplant recipients who survive long-term. METHODS: The pathologic and clinical records of 97 patients who underwent heart transplantation in Italy from 1985 to 1995 and died (85 of 97) or underwent retransplantation (12 of 97) at least 2 years after transplantation were surveyed. Graft failures were classified as late (occurring between 2 and 5 years after transplantation) and belated (more than 5 years). RESULTS: Graft vasculopathy was the single most common cause of death (40.0%) and the only cause of late retransplantation. Tumors ranked second (23.5% of deaths), but the expected non-Hodgkin's lymphomas and Kaposi's sarcoma were accompanied by a high number of lung cancers (especially metastasizing adenocarcinomas). They were followed by the emergence or recurrence of pretransplantation diseases (9.4%), fatal infections (exclusively bacterial) (4.7%), the development of transmissible diseases (viral hepatitis and acquired immunodeficiency syndrome, 4.7%), and late acute rejection (2.3%). The distribution of failures differed in the late and belated periods: death and organ loss proportions for graft vasculopathy, respectively, fell and rose from the late to the belated period; some types of malignancy and fatal acute rejection were never observed in the belated period, whereas the emergence of pretransplantation diseases prevailed in the belated period. Graft vasculopathy was more frequent and tumors were less frequent among patients undergoing transplantation for ischemic heart disease. CONCLUSIONS: The reasons why heart transplant recipients die or undergo retransplantation, respectively, in the late and belated periods slightly differ from one another and are widely different than in short-term survivors.

Bacterial Infections↗

PubMed1996

Detection of human cytomegalovirus myocardial involvement by polymerase chain reaction during systemic infection and correlation with pp65 antigenemia and DNAemia in infected heart recipients.

The presence of human cytomegalovirus DNA was investigated in 103 unfixed endomyocardial biopsies, performed during the first 4 months in 17 heart transplant recipients by polymerase chain reaction. Results were correlated with human cytomegalovirus systemic infection, as detected by the test for the viral lower matrix phosphoprotein pp65 (antigenemia) and by polymerase chain reaction for viral DNA in blood leukocytes (DNAemia). Three patients out of 17 did not develop cytomegalovirus infection and 14 did: 5 had symptomatic disease treated with ganciclovir and 9 developed asymptomatic infection and were not treated. Viral DNA was detected in 24 out of 103 biopsies (23%) from 13 patients: 5 with symptomatic infection during the acute phase of disease (mean levels of pp65: 125+/-232 pp65 positive leukocytes/200,000 examined cells) and 8 patients with asymptomatic infection when the mean antigenemia was 5+/-15/200,000 (4 patients) or when DNAnemia was present in the blood (4 patients). No histological evidence of myocarditis was shown in viral DNA-positive biopsies. No difference in acute rejection was found in viral DNA-positive and DNA-negative biopsy specimens in symptomatic and asymptomatic infected patients. Our experience suggests that during systemic symptomatic and asymptomatic cytomegalovirus infection, polymerase chain reaction can detect a relatively frequent myocardial involvement, but this involvement is not associated with myocarditis or with a higher incidence of acute rejection. THe presence of viral DNA in myocardial biopsies can be a result of high viremia, but it also can be due to low level of viral DNA in circulating infected leukocytes. Polymerase chain reaction is the most sensitive method for cytomegalovirus DNA detection in biopsies, but its results need to be evaluated together with morphology-preserving methods and systemic markers of infection in order to make a correct diagnosis.

Animals↗

PubMed1996

Recurrent secondary hyperparathyroidism due to parathyroid carcinoma: usefulness of Ki-67 immunostaining in the diagnosis of a malignant parathyroid tumor.

Parathyroid carcinoma is a very rare disease occurring in less than 2-3% of all the cases showing clinical features of primary hyperparathyroidism. Several histological markers have been used for distinguishing between benign and malignant tumors of the parathyroid glands. However, most of these markers are not easily applicable and clinical prognosis cannot be predicted by histopathological criteria alone. A recent study has drawn attention to the role of the cell cycle associated antigen Ki-67 detected by MIB-1 monoclonal immunocytochemistry in parathyroid tumors: in fact, Ki-67 seems to be a valuable marker of malignancy in such tumors since it permits an easy detection of proliferating and dividing cells. Here we report in detail a case of severe recurrent hyperparathyroidism in a 51-year-old female patient undergoing regular hemodialysis treatment. In the surgical specimens of the parathyroid glands, the tumor proliferative fraction of 56, expressed as the number of Ki-67-positive nuclei per thousand cells, and the mean mitosis count of 0.5, expressed as the percentage of the total amount of Ki-67 positive nuclei, support the diagnosis of parathyroid carcinoma despite the scanty amount of microscopical signs considered characteristic of malignancy, i.e. extensive thick fibrous bands or prominent nucleoli. To our knowledge this paper is the first clinical report that supports the diagnostic role of the cell cycle associated antigen Ki-67 in parathyroid carcinoma in a case of secondary hyperparathyroidism in a patient undergoing hemodialysis.

Female↗