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Biomedical subjects

L Guidi

Publications and source records attributed to L Guidi.

At least 73 records · Page 4Linked to original sources
PubMed1989

[Myocardial perfusion in coronary disease: thallium-201 planar scintigraphy].

This research evaluated the diagnostic and analytic effectiveness of 201-thallium imaging in a group of patients with coronary artery disease, each one of them with different localization, extent and number of coronary vessel obstructions. The thallium-201 imaging was performed immediately after ergometric test and repeated 4 hours later. In a large percentage of patients thallium-201 imaging of reversible and irreversible perfusion defects have been found; thallium-201 scintigraphy showed a greater sensitivity than exercise ECG. With particular evidence 201-Tl imaging showed perfusion defects in a high percentage of patients with obstruction of one and two coronary vessels; in these patients, in the former especially, the results of exercise ECGs showed a lower sensitivity. Both thallium-201 and exercise ECG had a similar sensitivity in patients with obstruction of three coronary vessels. In patients with obstruction of one or two vessels, thallium-201 imaging clearly showed a regional hypoperfusion corresponding to the specific perfusion coronary vessels, while exercise ECG gave aspecific topographic results. Irreversible perfusion defects resulted corresponding to the myocardial segments that were infarcted, but were also observed in patients without previous myocardial infarction.

Adult↗
PubMed1988

Visual involvement in Friedreich's ataxia: PERG and VEP study.

Neuro-ophthalmological assessment, including red-free light retinography, in conjunction with simultaneous visual evoked potential (VEP) and pattern electroretinogram (PERG) recordings were performed in 10 Friedreich's ataxia patients: 9 patients showed marked VEP abnormalities. Moderate PERG amplitude reduction, with normal latencies, was related to mild and scattered fiber loss revealed by red-free light retinography. The initial part of the visual pathways does not seem to be the main site of electrophysiological abnormalities as demonstrated by the greater extent and relative independence of VEP versus PERG alterations. Primary axonal degeneration of the optic nerve and tracts cannot account for all features of VEP abnormalities, thus implying some dysfunction in succeeding visual structures as well.

Adolescent↗
PubMed1988

[Soluble factors with immunosuppressive activity in human neoplasms].

A number of the mechanisms implicated in the phenomenon of immunosuppression present in tumour-carrying patients are described. In particular, stress is laid on factors soluble to immunosuppressive activity identified in the serum or in other biological fluids of these patients. From among these are analysed the circulating immunocomplexes, the proteins of the acute phase (alpha-globulins) and other inhibiting substances derived from tumour cells. The nature and origin of these substances are discussed as well as their effects on the cancer patient's immune system and the therapeutic type implications that arise in some cases.

Acute-Phase Proteins↗
PubMed1988

Immune complexes in solid tumours precipitable by 3.5% polyethylene glycol: analysis of some nonspecific components.

Some nonspecific components (IgG, C3c, C4,) of circulating immune complexes (IC) precipitable by 3.5% PEG were assayed by laser nephelometry in the sera of 71 patients with solid tumours, and of 39 patients with autoimmune diseases. PEG-IgG, PEG-C3c, and PEG-C4 were higher in cancer and in autoimmune diseases than in controls. In cancer patients, PEG-C4 levels and PEG-C4 positivity rate correlated well with tumour burden. PEG-C3c and PEG-IgG were present at higher levels and PEG-C4 was present at lower concentration in cancer than in autoimmune diseases. The results of the present study, performed on a large population of patients with cancer and autoimmune diseases, indicate a different composition of circulating IC in these diseases. Particularly, these data suggest a preferential involvement of the alternative pathway of complement activation in cancer, as already described by other authors. The aggregation of C3c to IC, mediated by the alternative pathway, seems to be the "key" event in the process of IC solubilization. In cancer patients' sera, the presence of "solubilized" IC could partly explain their peculiar biological behaviour as well as the disagreement observed among the different assay methods based upon the binding with complement factors.

Antigen-Antibody Complex↗
PubMed1987

[Rheumatoid factors, C-reactive protein and circulating immunocomplexes: laser-nephelometric determination using the latex aggregation method. Preliminary evaluation in rheumatoid arthritis].

C-reactive protein and rheumatoid factor assays are relevant laboratory parameters, among the most used in the clinical practice, being very useful in diagnosing and "monitoring" rheumatic diseases. A quantitative test to detect these two serum proteins is an important, more specific, new tool for clinical medicine. In our study we evaluated two new laser nephelometric assays, both quantitative, based on the agglutination of polystyrene latex particles, able to show serum concentration of CRP and RF. With a similar technique we tested the presence of circulating immune complexes. We performed our tests in a group of patients with rheumatoid arthritis, other autoimmune diseases, and healthy blood bank donors assaying simultaneously, whenever possible, the "classic" Rose-Waaler and RA tests. We found both methods easy to perform, well correlating with the semi-quantitative techniques and highly reproducible.

Antigen-Antibody Complex↗
PubMed1987

[Evaluation of isoenzymes of creatine kinase and lactate dehydrogenase in cases of suspected acute myocardial infarct].

In 176 patients who were hospitalized with a suspected anterior myocardial infarction, the total enzymatic activity of CPK and LDH in addition to the percentage of various isoenzymes have been determined through electrophoretic separation. The blood samples were taken upon the patients admittance to the hospital and repeated every 6 hours until the 24th hour after admittance. We have considered significant an increase of CPK-MB of more than 6% of the total, along with the LDH1/LDH2 ratio greater than 1. We have also taken into consideration the LDH1/LDH-total ratio. The patients were then subdivided into four groups and the results obtained were compared to the electrocardiographic data. Our results confirmed the need to examine both isoenzymatic groups for a correct laboratory diagnosis of anterior myocardial infarction.

Creatine Kinase↗
PubMed1985

Immune complexes and acute phase proteins in human cancer: preliminary evaluation by laser nephelometric techniques.

The serum levels of circulating immune complexes (IC) were evaluated by a new 'direct' laser nephelometric assay, concomitantly with four acute phase proteins (APP), in 167 patients with various neoplasms at different stages. The present study confirms the presence of IC in the sera of cancer patients and, in the breast cancer group, there is a significant correlation with the progression of the disease. Among the APP, in several cancer groups, C-reactive protein, haptoglobin and alpha 1-acid glycoprotein are more elevated than in controls, and a trend to display higher values is observed in the subjects with metastatic disease; particularly, the frequency of patients with 3 or more proteins above the normal levels is significantly higher in metastatic than in localized cancers (p less than 0.09).

Antigen-Antibody Complex↗
PubMed1981

Circulating immune complexes in myasthenia gravis: a study in relation to thymectomy, clinical severity and thymus histology.

Circulating immune complexes were assayed employing the method recently described by Barnett and Chia in a group of patients with myasthenia gravis. The subjects were classified according to clinical severity and immune complexes were sought before and after thymectomy. The operated subjects were further divided into those with thymoma or thymic hyperplasia. Antigen-antibody complexes were higher before thymectomy than after, in hyperplasias than in thymomas, and in severe myasthenia gravis than in mild disease. Circulating immune complexes and anti-acetylcholine receptor antibodies did not correlate.

Antigen-Antibody Complex↗
PubMed1981

Waldenström's macroglobulinemia and myasthenia gravis.

Until now, three patients with IgG and only one with IgM class monoclonal gammopathy (without the classical features of Waldenström's macroglobulinemia) have been reported in subjects with myasthenia gravis. A case of Waldenström's macroglobulinemia which occurred before thymectomy in a myasthenic patient is described in this paper. Both neuromuscular disease and the lymphocyte dyscrasia worsened after operation and before starting steroid treatment. No evidence of circulating immune complexes nor of anti-acetylcholine receptor antibodies belonging to the IgM class was found. The patient's HLA type shared A2 and B15 antigens with an IgG-lambda monoclonal gammopathy previously reported in a myasthenic woman, and his genotype included the Bw15 specificity which has been described to be frequent in Waldenström's macroglobulinemia. It appears that a persistent thymic abnormality, responsible for myasthenia gravis, may be associated with a lymphoreticular neoplasm.

Adult↗
PubMed1981

[Cardiovascular autonomic impairment in one case of acute pandysautonomia with recovery (author's transl)].

Pure acute Pandysautonomia (PAP), first described in 1969 by Young, is a rare but well defined clinical entity, in which the isolate involvement of Autonomic Nervous System (ANS) gives rise to a characteristic clinical admixture of symptoms and signs all due to the alteration of parasympathetic and sympathetic control of neurovegetative functions. The most prominent clinical features are: 1) postural hypotension without changes in heart rate leading to orthostatic syncopal or near-syncopal episodes, 2) abnormalities of intestinal tract and urinary bladder motility, leading to constipation alternating with diarrhea and urinary retention, 3) loss of sweating, 4) ocular abnormalities. We report a case of a 17 year old man with PAP, in whom almost complete resolution of clinical symptoms and signs of ANS involvement was observed within 9 months from the onset of illness. In our case, besides an accurate clinical and laboratory follow-up, particular attention was paid to investigate the cardiac responses to autonomic reflex tests and pharmacological interventions (atropine and beta-blocking drugs administration) during the entire course of illness. During the acute phase, complete vagal and almost complete beta-sympathetic "denervation" of the heart leading to disabling postural hypotension, fixed resting tachycardia and total unresponsiveness to Valsalva manoeuvre, were observed. PAP is a rare condition which must be known from cardiologists for a more complete knowledge of the etiology and pathophysiological mechanisms of postural syncopal attacks and must be distinguished from the less favourable progressive autonomic failure of the Shy-Drager syndrome.

Acute Disease↗
PubMed1980

Myasthenia gravis, thymectomy, and antiacetycholine receptor antibody.

The antiacetylcholine receptor antibody was titered in the serum of 63 patients with myasthenia gravis (MG) and 20 control healthy subjects. The titer was significantly high in 92% of MG patients in contrast with none of the controls and no correlation was found with the thymus pathology and the severity of the disease. The titer decreased after thymectomy almost steadily with the improvement of the myasthenic signs. The role of the antibody in the pathogenesis of the disease is discussed.

Acetylcholine↗
PubMed1980

IgD (kappa) "nonsecretory" multiple myeloma: report of a case.

A case of IgD "nonsecretory" multiple myeloma in a 46-yr-old woman is reported. Despite the presence of disseminated osteolytic lesions, both serum protein electrophoresis and serum and urine immunoelectrophoresis were normal. In addition, bone scintigraphic study was normal. Bone marrow biopsy and aspirate obtained from the left femur lytic lesion showed only myelomatous proplasmocytes; when examined by immunofluorescence with monospecifc antisera, the cytoplasm showed only the presence of delta and kappa chains, suggesting that the neoplastic plasma cells might belong to a single clone. Lymphocyte studies indicated the presence of a normal amount of both B and T cells.

Alpha-Globulins↗
PubMedDate not supplied

Plasma thrombin-antithrombin complexes, latent coagulation disorders and metastatic spread in lung cancer: a longitudinal study.

In patients affected with different tumours, disorders concerning clotting are frequently observed. The biological processes leading to coagulation are probably involved in the mechanisms of metastasis. We studied plasma levels of thrombin-antithrombin III complexes (TAT) in 90 patients affected with lung tumours subgrouped in small cell and non-small cell (NSC) lung cancer: 17 patients had no evidence of disease after surgery (NE); the remaining 73 patients were divided according to the absence (LOC) or the presence (META) of metastases. All the patients were followed up for several months. In all the lung cancer patient groups, at the beginning of the study we detected TAT levels that were higher than in controls. During the follow-up period, the NSC-NE patients with no recurrence of the disease as well as the NSC-LOC patients responding to the treatment had a decrease in TAT levels (p < 0.01 and p < 0.05, respectively). The NSC-META patients with progression of their disease had, in contrast, an increase in TAT levels (p < 0.01). Our data reveal the presence of 'latent coagulation disorders' as assessed by the presence of high TAT levels in the majority of lung cancer patients. The follow-up study indicates that in the NSC group, a relation exists between coagulation activation and rate of tumour progression and/or response to treatment. In cancer patients the early detection of coagulation disorders could also allow, therefore, the prevention of thromboembolism and/or haemorrhage by administration of appropriate treatment.

Antithrombin III↗
PubMedDate not supplied

Increased levels of NF-kappaB inhibitors (IkappaBalpha and IkappaBgamma) in the intestinal mucosa of Crohn's disease patients during infliximab treatment.

The treatment with infliximab is employed successfully in Crohn's disease (CD) but predictors of efficacy are lacking. Activation of the transcription factor NF-kB has been demonstrated in CD and its inhibition is one of the mechanisms by which anti-inflammatory agents exert their effects. We evaluated the production of TNFalpha by peripheral blood mononuclear cells (PBMC) and the levels of NF-kappaB family molecules in the intestinal mucosa during infliximab therapy in 12 patients. TNFalpha was assayed on supernatants of PBMC culture stimulated with PHA or LPS. Immunohistochemistry was also done on intestinal biopsies. In six patients, Western blot analysis of the NF-kappaB subunit Rel-A, and its inhibitors IkappaBalpha and IkappaBgamma was performed on intestinal biopsies and PBMC. The TNFalpha production by LPS stimulated PBMC showed mild changes, while it was increased by PHA-stimulated PBMC after treatment. The number of inflammatory cells in the intestinal mucosa was reduced (p<0.002) by the treatment. In five out of six cases we detected an increase of the IkappaBalpha and IkappaBgamma)inhibitor levels in intestinal biopsies after treatment. An increase of IkappaB inhibitors levels could be one of the mechanisms by which infliximab decreases NF-kappaB activity and exerts its anti-inflammatory effects.

Adult↗
PubMedDate not supplied

Pulmonary artery leiomyosarcoma with thyroid metastases.

Primary pulmonary artery sarcomas are uncommon and usually fatal tumours. The diagnosis of these tumours is delayed in most cases as they are mistaken for pulmonary thromboembolism. We present a fatal case of a woman referred to us five months after a primary diagnosis of pulmonary thromboembolism, due to an increase in dyspnea and presence of hemoptysis despite having undergone anticoagulant treatment. On the basis of the findings obtained by computed tomography, echocardiogram and MRI, a mass arising from the pulmonary trunk was evidenced, that suggested other diagnostic hypotheses. The worsening of patient's conditions did not allow an endovascular catheter biopsy and diagnosis was made at autopsy. The mass was a leiomyosarcoma of the pulmonary artery with thyroid metastases, which is an uncommon findings.

Autopsy↗
PubMedDate not supplied

Clinical correlations of small bowel CT and contrast radiology findings in Crohn's disease.

BACKGROUNDS AND OBJECTIVE: Aim of the present study was to evaluate the clinical correlates of small bowel CT patterns in patients with Crohn's disease (CD), as compared to barium studies and endoscopic findings, as far as parameters of disease activity are concerned. MATERIAL AND METHODS: Thirty five patients with pathologically proven CD were studied by means of helical single detector CT (13) or multidetector CT (22), after administration of low density contrast by mouth (13) or by nasojeunal tube (22). Eight hours later, all patients were studied with barium administered by mouth (13) or with barium and methilcellulose administered by nasojeunal tube (22). Clinical activity was assessed by CDAI score, ESR, CRP, alpha1 glycoprotein and fibrinogen levels. In twenty one patients, colonoscopy was also performed. RESULTS: Sensitivity of small bowel CT versus endoscopy was of 88% while sensitivity of barium studies was of 77% versus endoscopic findings, and it reached 100% for the combination of both exams. We found positive correlations between the detection at CT of "target sign" and a CDAI score > 150 or abnormal values of CRP, ESR, alpha1 glycoprotein. Abnormal ESR or fibrinogen levels were correlated with the detection of fistulas at CT scans. The diameter of enlarged mesenteric lymph nodes was correlated with alpha1 glycoprotein values. No similar correlations were detected for contrast radiology findings. DISCUSSION: This study underscores the clinical usefulness of performing small bowel CT in adjunct to conventional diagnostic studies in Crohn's disease patients. CT findings (either by oral route or nasojeunal tube) correlate with parameters of disease activity.

Adult↗