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Biomedical subjects

M Salvetti

Publications and source records attributed to M Salvetti.

At least 91 records · Page 5Linked to original sources

[Self-expanding metal stents in the treatment of neoplastic esophageal stenosis. The technic and preliminary results].

Self-expanding metal stents have been recently used for the treatment of neoplastic esophageal stenoses. In our series, nitinol Strecker stents were implanted in ten patients with malignant esophageal intrinsic or extrinsic strictures, as a definitive palliation. Thirteen stents in all were used: two stents were positioned in three patients to recanalize the esophagus. The prostheses could always be inserted in the treated patients and in all of them swallowing was markedly improved. No major early complications were observed after stent insertion. All the stents but one were patent until the patient's death. Two patients are alive and bearing well-functioning stents. Self-expanding metal stents are to be preferred to plastic endoscopic tubes because their caliber is smaller at the time of insertion and they do not require general anesthesia, as endoscopic tubes sometimes require. Moreover, their complication rate is lower for both early and late complications. Tumor ingrowth through the stent mesh with stent occlusion is the major pitfall of these prostheses, together with the impossibility to use them when esophageal fistulas are present: these limitations will be soon overcome when silicone-coated expandable stents are on the market.

Aged↗

[Digital fluorography in gastroenterological radiology].

The clinical value of two digital fluoroscopy systems not connected to a PACS was investigated and compared with that of conventional radiology. Some critical variables were considered: image intensifier diameter, image definition, examination time, acquisition speed, patient exposure and finally film consumption. The main problems in the use of the digital techniques consisted in the limited size of the examination fields, which was not big enough to demonstrate the whole colon during double contrast enema, and in the difficult representation of the actual size on the image printed on the laser films. Definition was considered as sufficient for GI examinations. The main advantages consisted in acquisition speed, allowing detailed examinations of cervical esophagus, cardias and fistulous tracts, reduced patient dose and finally the real time visualization of the acquired image on the TV monitor.

Digestive System↗

Predominant and stable T cell responses to regions of myelin basic protein can be detected in individual patients with multiple sclerosis.

T lymphocytes from patients with multiple sclerosis (MS) recognize multiple myelin basic protein (MBP) epitopes. This situation complicates the design of specific immunotherapies. We investigated to which extent the T cell response to MBP is heterogeneous in single subjects in terms of preferentially recognized regions of the molecule, major histocompatibility complex (MHC) restriction, and stability over time. From each of nine patients with MS, a minimum of six MBP-specific T lymphocyte lines (TLL) were assayed for the proliferative response to a panel of overlapping peptides, encompassing the whole MBP. Predominant T cell recognitions of distinct MBP regions were present in three patients, all HLA-DR2+, independently of the clinical features of their disease. T cell reactivity was preferentially directed to residues 16-38 in one patient. In this case the response was also stable over time, during different phases of the disease. Predominant reactivity to residues 86-99 was detected in the two other DR2+ patients. In each of the patients with other HLA-DR haplotypes (DR2-), as well as in three DR2+ non-MS donors, the T cell response to MBP appeared to be considerably more heterogeneous. The HLA restriction element varied among TLL recognizing the same MBP region, even when raised from the same individual. The genomic HLA typing, performed on the DRB1 and DRB5 genes in the DR2+ subjects, showed no obvious correspondence between preferential responses to regions of MBP and HLA-DR2 subtypes. In this context, a simple, new method for the genomic typing of the HLA-DRB1 gene in individuals with the HLA-DR2 serological specificity is also described. We conclude that predominant and stable T cell responses to a single MBP region can be detected in some patients with MS. In these individuals, the MHC restriction of the T cell recognition of predominant regions appears to be variable. Polymorphisms of the HLA-DR2 gene products alone do not account for the selection of the dominant MBP T cell epitope.

Adolescent↗

Target epitopes of myelin basic protein specific T cell lines in multiple sclerosis.

A highly efficient new method for the generation of antigen specific T cell lines (TCL) is now available. By this method we established 134 myelin basic protein (MBP) TCL from the peripheral blood of 9 patients with definite multiple sclerosis (n = 69) and 8 healthy donors (n = 65). The yield of MBP reactive TCL in the two groups was comparable. So far 22 MBP specific TCL from 7 patients and 24 from 7 healthy individuals have been tested for their proliferative response to a panel of four synthetic peptides representing MBP residues 7-26, 80-99, 139-153 and 148-162. Although the peptide sequences did not encompass the whole MBP, the pattern of reactivity to these peptides in patients and controls seems to be similar. Further, when multiple TCL from the same donor were analysed, no dominant recognition emerged.

Adult↗

New approaches to the study of T cell autoimmunity in multiple sclerosis. Meeting report on the 2nd Workshop on T cell Autoimmunity in MS, Perugia, Italy, 26-28 November, 1992.

This report discusses some of the papers presented during the 2nd T Cell Autoimmunity in MS Workshop held in Perugia on November 26-28, 1992. The 'trait d'union' of the meeting was the awareness that recent studies have failed to uncover clear-cut differences in T cell reactivity to autoantigens between patients with multiple sclerosis and healthy individuals. Hence, new strategies have been proposed to try to distinguish between 'pathological' autoimmunity in patients and 'natural' autoimmunity in healthy individuals. Furthermore, the studies have been extended to new potential autoantigens (myelin constituents other than myelin basic protein, superantigens, heat shock proteins) and new susceptibility genes such as those coding for transport-associated proteins (Tap-1 and Tap-2).

Autoimmune Diseases↗

T-lymphocyte reactivity to the recombinant mycobacterial 65- and 70-kDa heat shock proteins in multiple sclerosis.

Owing to their conservation and immunogenicity, heat shock proteins (hsps) represent a class of potential autoantigens. Moreover, they could be targets for gamma delta T lymphocytes, which are prominent in various immune disorders. We studied the T cell proliferative primary responses to recombinant M. bovis 65 kDa hsp (hsp65) and M. tuberculosis 70 kDa hsp (hsp70) in 31 patients with multiple sclerosis (MS), 19 patients with other neurological diseases (OND) and 19 healthy individuals. Positive responses to hsp70, but not to hsp65 were significantly more frequent in patients with MS than in patients with OND or in healthy individuals. In order to verify and refine these results and to characterize the hsp reactive T lymphocytes, we screened 147 PPD-specific long-term T cell lines (76 from 10 patients with MS and 71 from 12 healthy donors) for their proliferative response to hsp65 and hsp70. hsp70-reactive T lines were significantly more common in patients with MS than in healthy controls. The number of T lines responding to hsp65 increased in the MS group only slightly. In 19 T lymphocyte lines from patients with MS and healthy donors, a cytofluorometric analysis was performed with special attention paid to distinct T cell receptor gamma delta determinants. With one exception, in each line the population of gamma delta T cells remained a minority. We conclude that an increased T cell response to mycobacterial hsp70 may be present in patients with multiple sclerosis.

Adolescent↗

Structural brain correlates of neurologic abnormalities in multiple sclerosis.

We examined the relationship between cerebral magnetic resonance imaging (MRI) findings and urinary dysfunction in 70 consecutive patients with definite multiple sclerosis. MRI-weighted lesion scores for seven different brain regions were recorded according to the number and size of cerebral lesions. Thirty-two subjects (46%) had urinary symptoms and 38 (54%) were asymptomatic. Subjects with urinary symptoms exhibited greater overall functional disability and a higher midbrain MRI-weighted lesion score than asymptomatic patients. No statistically significant group differences were found for the other brain regions.

Adolescent↗

Embolization and chemoembolization for hepatocellular carcinoma.

A check on the rationale for embolization and chemoembolization for hepatocellular carcinoma and a revisit to the background of the anatomy of blood supply to the liver is discussed. The technique of the embolization is different and mostly in the range of home made configuration. There is no data concerning the stability of different choices such as the popular mixture of cytotoxic agents and lipiodol. Therefore the authors have preferred the use of microencapsulated Mitomycin believing that this special formulation of the drug can attain the present best reproducibility. The survival of 32 treated patients was longer than the control group. Twelve, 36 and 60 month survival was 70%, 45% and 15% vs 37%, 0%, and 0% respectively.

Capsules↗

Tumour necrosis factor-alpha synthesis by cerebrospinal-fluid-derived T cell clones from patients with multiple sclerosis.

T-cell clones derived from the CSF (cerebrospinal fluid) of MS (multiple sclerosis) patients have been analysed for the production of interferon-gamma (IFN-gamma), tumour necrosis factor-alpha (TNF-alpha), interleukin-2 (IL-2) and interleukin-4 (IL-4). Each CSF-T clone (both CD4+ and CD8+) produced substantial amounts of IFN-gamma and especially TNF-alpha compared with autologous peripheral T clones and liver-infiltrating T clones from patients with chronic active hepatitis. The large quantities of TNF produced by CSF-T cell clones suggest an important role for this cytokine in MS immunopathogenesis.

Adult↗

Hemianopic ataxic hemiparesis. A case report.

Ataxic hemiparesis and homonimous hemianopia developed in a hypertensive 60-year-old woman. Magnetic resonance imaging detected multiple lesions in the territory of distribution of the posterior cerebral artery and in the inferior region of the left cerebellar hemisphere. At computed tomography only a right hypodense area involving the posterior right thalamus, the postero-medial region of the temporal lobe and the occipital lobe was evident.

Ataxia↗

[Combined use of real-time digital subtraction radioscopy and computerized tomography: potential advantages in diagnostic and interventional radiology].

The idea of combining fluoroscopy and CT arose from the daily practice in diagnostic and interventional radiology. A Diasonics OEC high-performance image intensifier complete with a digital subtraction system was connected to a Siemens Somatom-DRH CT scanner to work in tandem. CT is used for a localization in-depth and fluoroscopy for the subsequent maneuvers within an organ or body compartment. With this combination, complex procedures such as transarterial portography, percutaneous embolizations, pain treatment and manipulation for catheterization of the bile ducts and urinary tract could be performed in one place and in one session. CTF is especially useful when patients should not be moved about from room to room or undergo an examination in several sessions, as it happens with children or critically ill or contagious patients.

Adult↗

Flexibility and efficacy of automatic continuous fluorodeoxyuridine infusion in metastases from a renal cell carcinoma.

Complete and lasting control of diffuse metastases from a renal cell carcinoma has been achieved by automatic continuous infusion of a single cytotoxic agent, fluorodeoxyuridine (FUDR). A patient with a single brain metastasis from renal cell carcinoma developed pulmonary, mediastinal, and retroperitoneal metastases after radical nephrectomy. A Medtronic Synchromed pump (Medtronic Inc., Minneapolis, MN) was implanted for the circadian systemic infusion of FUDR in 14-day courses with 14-day drug-free intervals. A complete response (CR) at all sites, was obtained in 3 months, and maintained for 22 months. After a second brain metastasis, treated by radiation therapy and cisplatin as radiosensitizer, a CR was obtained again and is now of 31 months' duration, which is four times the record to date. The overall hospitalization was 2 days. Acceptance of the pump is excellent and it functions precisely and reliably. This case should stimulate greater interest in techniques of automatic continuous infusion of cytostatics, given its greater efficacy and lower toxicity.

Brain Neoplasms↗

Acetylcholine receptor-specific T-lymphocyte clones in the normal human immune repertoire: target epitopes, HLA restriction, and membrane phenotypes.

Potentially autoimmune T-lymphocyte lines specific for the nicotinic acetylcholine receptor of the neuromuscular junction have been isolated previously from patients with myasthenia gravis. We report on the isolation and expansion of T cells specific for the acetylcholine receptor of Torpedo californica or for a recombinant mammalian acetylcholine receptor alpha chain peptide (X4), from the peripheral blood of 11 healthy donors. Two major T-cell epitopes, located between amino acid positions 44-104 and 141-172, were identified using a panel of overlapping mammalian alpha chain fusion proteins. Most T lines recognized the acetylcholine receptor epitopes in the molecular context of HLA-DR molecules. Unexpectedly, all the T. californica acetylcholine receptor-specific T lines obtained from one DR4 (DRw53), DQw3 donor and two DR4, w8 (DRw53), DQw3 donors were restricted by DRw53 product(s). Using DR gene-transfected L cells as antigen presenters, in 4 lines, a close relationship between the recognized epitope and the restricting DR element was revealed. The membrane phenotype of the T. californica acetylcholine receptor-and X4-specific T lines was predominantly CD4+CD8-, with some CD4+CD8+ components. It did not significantly differ from that of control, tuberculin purified protein derivate-specific T lines raised from the same donors. These findings are in harmony with previous ones demonstrating the presence of potentially autoimmune T-lymphocyte clones within normal immune repertoires.

Antigens, CD↗

Staging of hepatocellular carcinoma by ultrasonography, computed tomography, and angiography: the role of CT combined with arterial portography.

A series of 60 patients with hepatocellular carcinoma (HCC) were evaluated over a 2-year period of ultrasonography (US), computed tomography (CT), and angiography. The angiographic studies carried out with intraarterial digital technology were compared to both US and CT of the liver. In 16 of 60 patients, we observed discordance of the findings obtained with angiography, CT, and US. We therefore compared these three methodologies in those cases where diagnostic discordance was noted. In our experience, US had a sensitivity of 73.4%, 76.7% for CT, and 95% for angiography. In 13 of 60 patients, we performed CT with arterial portography (CTAP) which demonstrated a better resolution than conventional CT. In view of the sensitivity of US - comparable to that of CT - and for the even greater sensitivity of intraarterial digital angiography, we performed an US study of patients at risk of HCC. CT was found to play a diagnostic/staging role after angiographic study has been performed, especially when enhanced by arterial portography.

Adult↗

Circadian continuous chemotherapy of renal cell carcinoma with an implantable, programmable infusion pump.

The authors treated 42 metastatic renal cell carcinoma (RCC) patients who had received no previous chemotherapy or radiation therapy with circadian venous continuous infusion of 5-fluoro-2-deoxyuridine (FUDR). The drug was delivered by Medtronic Synchromed implantable pump (Medtronic, Inc., Minneapolis, MN) in 14-day cycles alternating with 14-day intervals of heparinized physiologic saline infusion. In the course of 24 months 444 cycles of therapy have been given for a total of 12449 days of pump function. Of the patients observed for at least 3 months (range, 3 to 23 months; median, 7 months) three showed complete response (7%; 95% confidence interval, 0% to 15%), three partial response (7%; confidence interval, 0% to 15%), 18 stable disease, and 18 showed progression. Eighteen patients, all with advanced disease at the time of implantation, were living 6 months after treatment started. Circadian continuous central venous infusion of FUDR is minimally toxic. The FUDR can be delivered safely and conveniently in this way for long spans. This therapy is as active as any currently available treatment, is administered in an entirely outpatient setting, and is associated with a normal quality of life.

Adult↗