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Biomedical subjects

M Monti

Publications and source records attributed to M Monti.

At least 55 records · Page 3Linked to original sources

[Treatment of pilonidal sinus with the Limberg's technique].

The Authors describe sinus pilonidalis disease and report their experience of two principal surgical techniques: the closed method and the Limberg cutaneous skin flap. They conclude that both the methods are recommended for a good clinical result.

Adolescent↗

[Non-parasitic splenic cysts].

The Authors report their experience matured during the last decade in the Institute of III Surgical Clinic of the University "La Sapienza" in Rome, relatively to 174 patients operated of splenectomy of which 8 for not parassitair benign cystic pathology. After the nosologic organization of the varied types of cystics splenopaty is examined the different symptomatology and is discussed the different treatment.

Adult↗

Microspectrofluorometry and fluorescence imaging in the study of human cytopathology.

The study of energy pools and dynamics of specific pathways in living cells by microspectrofluorometry and fluorescence imaging produces spectral and topographic images characterizing structural and functional changes associated with cytopathology. Microspectro-fluorometry and fluorescence imaging have been applied, together with organelle morphometry to a number of cells mimicking certain cytopathologies, including melanoma cells, long-term malignant cells, and gene-defective cells. These investigations of cellular pathology indicate that there is a convergence of various physiopathological processes. Cellular states that have similarities include senescence, detoxification, and transformation. While the NAD(P)H metabolic transients have been studied before, our emphasis in this article is on very rapidly scanned fluorescence images related to organelle integration and photoinduced cellular senescence.

Animals↗

Experimental real-time phase synchronization of a paced chaotic plasma discharge.

Experimental phase synchronization of chaos in a plasma discharge is studied using a phase variable lift technique (i.e., phase points separated by 2pi are not considered as the same). Real-time observation of synchronized and unsynchronized states is made possible through a real-time sampling procedure. Parameter space regions of synchronization and unsynchronization are identified, and a set of equations is suggested to model the real plasma circuit.

Journal Article↗

Impact of delirium on the short term prognosis of advanced cancer patients. Italian Multicenter Study Group on Palliative Care.

BACKGROUND: The objective of this study was to evaluate the impact of delirium on the survival of advanced cancer patients also assessed with a validated prognostic score (the palliative prognostic [PaP] score). METHODS: The study population was a prospective multicenter consecutive case series of advanced cancer patients for whom chemotherapy was no longer considered viable and who were referred to palliative care programs. Clinical and biologic prognostic factors included in the PaP score were assessed at study entry. The Confusion Assessment Method criteria were applied to screen patients presenting with delirium. Survival times were measured from time of enrollment and death taken as an outcome. Survival curves were traced with the Kaplan-Meier method and comparison were based on log rank tests. RESULTS: Delirium was found in 109 cases among 393 consecutive patients (27.7%). The diagnosis of delirium was independently associated with male gender, central nervous system metastases, lower performance status, worse clinical prediction of survival, and progestational treatment. The survival curve of patients with delirium was significantly different from the nondelirious patients curve (log rank, 31.6, P < 0.0001). The median survival time was 21 days (95% confidence interval [CI], 16-27) for the delirious patients and 39 days (95% CI 33-49) for the others. Multivariate analysis showed that the diagnosis of delirium and PaP score were independently associated with prognosis. CONCLUSIONS: The diagnosis of delirium significantly worsens life expectancy prognosticated with the PaP score. By using the PaP score together with the assessment of cognitive status, physicians can correctly predict patients 30-day survival in greater than 70% of cases.

Adolescent↗

T(14;18) translocation in chronic hepatitis C virus infection.

Pathogenic mechanisms of B-cell lymphoproliferative disorders in chronic hepatitis C virus (HCV) infection are unclear. We studied t(14;18) translocation by polymerase chain reaction in peripheral blood mononuclear cells from 50 patients with HCV-related liver disease (group A), 7 with mixed cryoglobulinemia syndrome (group B), 55 with HCV-negative liver disease (group C), and 30 with HCV-negative chronic rheumatic disorders or chronic infection by nonhepatotropic agents (group D). T(14;18) was significantly more frequent in group A (13/50 patients = 26 %) and group B (5/7 = 71.4%) patients than in group C (1/55 = 3.6%) and group D (1/30 = 3.3%) ones. Immunoblot analysis showed bcl-2 over-expression in all t(14;18)-positive samples. In group A, 10/13 (77%) patients with t(14;18) and 13/37 (35%) without t(14;18) had serum cryoglobulins in the absence of mixed cryoglobulinemia symptoms (P <.05). These data indicate that t(14;18) and bcl-2 over-expression in lymphoid cells are frequent in chronic HCV infection and suggest that this event may contribute to the pathogenesis of HCV-related lymphoproliferative disorders.

Aged↗

Efficiency of organ procurement and transplantation programs.

The number of donations per million population (pmp) per year and the number of transplants pmp/year enables one to compare donation or transplant programs made in different years in the same area or made the same year in different areas. These pmp indexes may be integrated with an evaluation system by which each organ is evaluated separately in terms of the efficiency of its procurement and transplant systems using the procurement index (percentage in terms of number of organs utilized/number of organs procurable from donors utilized in a single area during 1 year) and the transplant index (percentage in terms of number of transplants performed/number of organs harvested in a single area during 1 year). We have called them Caldes I (procurement) and Caldes II (transplant) indexes. The harvest index evaluates the efficiency of utilization of organs retrieved from suitable donors. It usually ranges between 80-90% for the kidney, 70-95% for the liver, 40-50% for the heart, and 5-15% for the lungs. The transplant index evaluates for each organ the transplant team capacity to use available organs which can be harvested locally or in different areas. It usually ranges between 60-120%. Index determination did not require information different from the standard data available. Both the harvest and transplant indexes could be used to compare the efficiency of donation and transplant programs and policies in the same area during different years or at the same time in different areas. They can be critical in evaluating: (a) marginal donor utilization, (b) marginal organ utilization, and (c) dishomogeneity of organ retrieval and organ transplantation in different regions belonging to the same area. They also enable to evaluate if organs considered not available in a single area are offered to other areas or are not retrieved at all from available donors.

Efficiency, Organizational↗

High concentrations of the vascular endothelial growth factor and interleukin-8 in ovarian endometriomata.

Patients with endometriosis are characterized by the ability of the endometrium to implant and by the peritoneal response to the tissue; angiogenic factors may play a significant role in the aetiology of endometriosis supporting the implantation of ectopic endometrial cells. Vascular endothelial growth factor (VEGF) is a mitogen, morphogen and chemoactractant for endothelial cells and, in vivo, it is a powerful mediator for vessel permeability. Interleukin-8 (IL-8) is a chemoatractant for neutrophils and is a potent angiogenic factor. Women (n = 20) with ovarian endometriomata and 10 women with follicular cysts were enrolled in this study to investigate the role of VEGF and IL-8 in the development and maintenance of ovarian endometriomata. Cystic fluids were collected by laparoscopy, immediately centrifuged and stored until the enzyme-linked immunosorbent assays were performed. The VEGF and IL-8 concentrations were found to be significantly higher in the fluids of the ovarian endometriomata than in those of the follicular cysts of controls (P < 0.001 and P < 0.001 respectively); in addition, a significant inverse correlation between the VEGF cystic fluid concentrations and the diameter of the endometriotic adnexal masses was found (r = -0.56, P = 0.01). The evidence that the high concentrations of VEGF and IL-8 are present in the ovarian endometriomata indicates that angiogenesis could be a specific event both for the progression and maintenance of such cysts.

Adult↗

Removal of the N-terminal hexapeptide from human beta2-microglobulin facilitates protein aggregation and fibril formation.

The solution structure and stability of N-terminally truncated beta2-microglobulin (deltaN6beta2-m), the major modification in ex vivo fibrils, have been investigated by a variety of biophysical techniques. The results show that deltaN6beta2-m has a free energy of stabilization that is reduced by 2.5 kcal/mol compared to the intact protein. Hydrogen exchange of a mixture of the truncated and full-length proteins at microM concentrations at pH 6.5 monitored by electrospray mass spectrometry reveals that deltaN6beta2-m is significantly less protected than its wild-type counterpart. Analysis of deltaN6beta2-m by NMR shows that this loss of protection occurs in beta strands I, III, and part of II. At mM concentration gel filtration analysis shows that deltaN6beta2-m forms a series of oligomers, including trimers and tetramers, and NMR analysis indicates that strand V is involved in intermolecular interactions that stabilize this association. The truncated species of beta2-microglobulin was found to have a higher tendency to self-associate than the intact molecule, and unlike wild-type protein, is able to form amyloid fibrils at physiological pH. Limited proteolysis experiments and analysis by mass spectrometry support the conformational modifications identified by NMR and suggest that deltaN6beta2-m could be a key intermediate of a proteolytic pathway of beta2-microglobulin. Overall, the data suggest that removal of the six residues from the N-terminus of beta2-microglobulin has a major effect on the stability of the overall fold. Part of the tertiary structure is preserved substantially by the disulfide bridge between Cys25 and Cys80, but the pairing between beta-strands far removed from this constrain is greatly perturbed.

Amino Acid Sequence↗

Organ donation and transplantation as health programs in Italy.

Organ and tissue donation and transplantation have a role in public health programs as organizational projects designed by public health departments to increase the quality and number of donations and transplantations. These programs serve as communication projects to inform public opinion on cerebral death, organ and tissue shortages, procurement and allocation rules, and the quality of life of transplanted patients. The health department of Emilia-Romagna created a regional law and a multimedia communication program for these purposes, resulting in a 95% increase of cadaver donor in 4 years. In 1995, regional activity reached the European mean level and afterwards surpassed it. In 1997, the bone bank was activated, followed in 1998 by the heart valve and vascular segment bank. The regional health department now considers transplant activities a primary goal; human and professional relations between intensive care units and the transplant reference center are considered crucial; cooperation among health departments, medical teams involved in organ procurement and transplant activities has been fostered, and the local coordination network has been active and efficient. The public information campaign has proven important in providing information both to professionals and citizens.

Health Care Rationing↗

Structural analysis and disulfide-bridge pairing of two odorant-binding proteins from Bombyx mori.

Pheromone-binding protein (PBP) and general odorant-binding proteins (GOBPs) were purified from the antennae of Bombyx mori and structurally characterised. The amino acid sequence of GOBP-2 has been corrected. The disulphide arrangements of PBP and GOBP-2 have been determined by a combined mass spectrometric/Edman degradation approach. The same cysteine pairings, Cys19-Cys54, Cys50-Cys108, and Cys97-Cys117, were found in both proteins, suggesting that such patterns occur commonly throughout this family of molecules. This arrangement of disulphide bonds indicates that the three-dimensional structure of insect OBPs is defined by three loops, rich in helical content, which can vary in size and charge distribution from one protein to another.

Amino Acid Sequence↗

Topology of the thyroid transcription factor 1 homeodomain-DNA complex.

The topology of the thyroid transcription factor 1 homeodomain (TTF-1HD)-DNA complex was investigated by a strategy which combines limited proteolysis and selective chemical modification experiments with mass spectrometry methodologies. When limited proteolysis digestions were carried out with the protein in the absence or presence of its target oligonucleotide, differential peptide maps were obtained from which the amino acid residues involved in the interaction could be inferred. Similarly, selective acetylation of lysine residues in both the isolated and the complexed homeodomain allowed us to identify the amino acids protected by the interaction with DNA. Surface topology analysis of isolated TTF-1HD performed at neutral pH was in good agreement with the three-dimensional structure of the molecule as determined by NMR studies under acidic conditions. Minor differences were detected in the C-terminal region of the protein which, contrary to NMR data, showed no accessibility to proteases. Analysis of the complex provided an experimental validation of the model proposed on the basis of the homology with the homeodomain structures described so far. An increased accessibility of the C-terminal region was observed following the interaction, suggesting its displacement from the protein core by the oligonucleotide molecule. Comparative experiments with DNA fragments differing in sequence and binding capabilities highlighted structural differences among the complexes, mainly located in the N-terminal region of the homeodomain, thus accounting for their different dissociation constants.

Acetylation↗

Prevalence of mixed infection by different hepatitis C virus genotypes in patients with hepatitis C virus-related chronic liver disease.

Multiple infection by different hepatitis C virus (HCV) genotypes may be of great clinico-pathologic interest. In this study we determined the effective prevalence of coinfections by two or more HCV genotypes in 213 subjects with HCV-positive chronic hepatitis by using genotype-specific polymerase chain reaction (PCR), genotype-specific probe hybridization, and direct sequencing. The most prevalent genotype was HCV-1b (54%). HCV-2 (a/c) was also prevalent (27%), and types 1a and 3a were found in 5% and 3% of patients, respectively. A mixed infection was detected in 23 patients (10.8%): 4 out of 23 were coinfected by types 1a + 1b, while the remaining 19 patients had a b + 2 (a/c) mixed infection. Further analysis based on restriction fragment length polymorphism (RFLP) on type-specific PCR products was used to verify genotyping results. Only four coinfections (1a + 1b in 2 patients and 1b + 2 (a/c) in the remaining 2 patients, respectively) were confirmed by enzyme cleavage. All patients with true coinfection had long-lasting infection and liver cirrhosis. Both true and false mixed infections resulting from RFLP analysis were confirmed by direct sequencing of type-specific amplification products. We also determined a recurrent C/T transversion at position 618 in all sequenced samples. In 4 cases another point mutation (G/A at position 626) was found, reducing the number of mismatches between HCV-2 and HCV-1b from 4 to 3 (or 2). Interestingly, all HCV-2 isolates sequenced showed the highest degree of nucleotide homology with HCV-2 subtype c, confirming the relatively high prevalence of this subtype in Italy. In conclusion, we showed the possibility of multiple infection by different HCV types in the general population of chronically infected patients without particular risk factors, even if in a low percentage of cases. Further studies are needed to assess the clinical relevance of chronic HCV infection with multiple genotypes.

Adult↗

Successful validation of the palliative prognostic score in terminally ill cancer patients. Italian Multicenter Study Group on Palliative Care.

The aim of this work was to validate a previously constructed prognostic score for terminally ill cancer patients in order to determine its value in clinical practice. The Palliative Prognostic Score (PaP Score) was tested on a population of 451 evaluable patients consecutively entered in the hospice programs of 14 Italian Palliative Care Centers. The score subdivided patients into three specific risk classes based on the following six predictive factors of death: dyspnea, anorexia, Karnofsky Performance Status (KPS), Clinical Prediction of Survival (CPS), total white blood count (WBC), and lymphocyte percentage. The performance of the PaP Score index in the training and testing sets was evaluated by comparing mortality rates in the 3 prognostic risk categories. The score was able to subdivide the validation-independent case series into three risk groups. Median survival was 76 days in group A (with a 86.6% probability of 30-day survival), 32 days in group B (with a 51.6% probability of 30-day survival), and 14 days in group C (with a 16.9% probability of 30-day survival). Survival medians were remarkably similar to those of the training set (64 days in group A, 32 days in group B, and 11 days in group C). In the complex process of staging terminally ill patients, the PaP Score is a simple instrument which permits a more accurate quantification of expected survival. It has been validated on an independent case series and is thus suitable for use in clinical practice.

Algorithms↗

Severe cutaneous cholesterol emboli syndrome after coronary angiography.

Cholesterol embolization syndrome is due to dislodgment of cholesterol crystals from the atherosclerotic plaques lining the walls of major arteries resulting in an occlusion of small arteries. We describe a case of severe cutaneous cholesterol emboli syndrome following repeat coronary angiography showing by our observation that this syndrome is often unrecognized or misdiagnosed and that a better evaluation of risks factors in patients undergoing invasive procedures could prevent this severe complication.

Aged↗

Purification, structural characterization, cloning and immunocytochemical localization of chemoreception proteins from Schistocerca gregaria.

Soluble low-molecular-mass protein isoforms were purified from chemosensory organs (antennae, tarsi and labrum) of the desert locust Schistocerca gregaria. Five genes encoding proteins of this group were amplified by PCR from cDNAs of tarsi and sequenced. Their expression products are polypeptide chains of 109 amino acids showing 40-50% sequence identity with putative olfactory proteins from Drosophila melanogaster and Cactoblastis cactorum. Direct structural investigation on isoforms purified from chemosensory organs revealed the presence in the expression products of two of the genes cloned. Two additional protein isoforms were detected and their molecular structure exhaustively characterized. MS analysis of all isoforms demonstrated that the four cysteine residues conserved in the polypeptide chain were involved in disulfide bridges (Cys29-Cys38 and Cys57-Cys60) and indicated the absence of any additional post-translational modifications. Immunocytochemistry experiments, performed with rabbit antiserum raised against the protein isoform mixture, showed selective labelling of the outer lymph in contact sensilla of tarsi, maxillary palps and antennae. Other types of sensilla were not labelled, nor were the cuticle and dendrites of the sensory cells. No binding of radioactively labelled glucose or bicarbonate was detected, in disagreement with the hypothesis that this class of proteins is involved in the CO2-sensing cascade. Our experimental data suggest that the proteins described here could be involved in contact chemoreception in Orthoptera.

Amino Acid Sequence↗

Hepatitis C virus (HCV) in cryoglobulinaemic leukocytoclastic vasculitis (LCV): could the presence of HCV in skin lesions be related to T CD8+ lymphocytes, HLA-DR and ICAM-1 expression?

An association between mixed cryoglobulinaemia (MC) and hepatotropic viruses, chiefly hepatitis C virus (HCV), has been widely reported. The presence of HCV genomic sequences or HCV-related viral proteins in the serum, purified cryoglobulins, peripheral blood mononuclear cells and into several tissues has suggested an important triggering role for HCV in MC patients. However, only few reports investigated the presence of HCV in cutaneous vasculitis and its potential pathogenetic role. Biopsies of cutaneous purpuric lesions from 5 MC female patients (aged from 40 to 80 years) were carried out for virological and histopathological evaluation. A leukocytoclastic vasculitis pattern was found in 4/5 subjects, while the presence of HCV RNA was detected in 3/5. In only 3 cases biopsy specimens were sufficient for immunohistochemical and direct immunofluorescence (DIF) studies. Immunohistochemical evaluation was performed by means of alkaline phosphatase and monoclonal anti-alkaline phosphatase (APAAP) immune-complexes. In the same skin specimen APAAP and DIF findings were compared with the presence/absence of HCV genomic sequences (PCR technique). In 1 MC patient, the detection of HCV-RNA was associated to a prevalent CD8+ T suppressor pattern with a perivascular and subjunctional distribution as well as an intense expression of second class (HLA-DR) and intercellular adhesion (ICAM-1) molecules on basal keratinocytes, endothelial cells and perivascular infiltrate. These findings suggest a marked inflammatory activation that spreads from endothelial cells to keratinocytes and Langerhans cells. In the 2 HCV-RNA negative specimens the scanty immunopathological staining could indicate a residual activity due to the previous inflammatory event triggered by cryoglobulins. The deposition of circulating HCV-containing immune complexes (CIC) in the skin could be the initial pathogenic event for cryoglobulinemic vasculitis; subsequently CIC could spread from the vascular bed to the perivascular tissue and then could be very rapidly eliminated. If confirmed in larger patients' series these findings could definitely demonstrate a direct role of HCV in the pathogenesis of cryoglobulinemic vasculitis.

Adult↗