Biomedical subjects
Publications and source records attributed to L Bonomo.
High-dose cyclophosphamide can be used to obtain haematological stem cells from the peripheral blood. In this paper we analyse the dynamics of appearance of cells with these characteristics, together with the impact of this drug on the immunological system. Cyclophosphamide seems to possess immunomodulating effects even at high doses.
Acknowledging fissure invasion by pulmonary tumors located in contact with or in the vicinity of a fissure is an important piece of information for the therapeutic choice, especially in patients whose functional respiratory impairments are a contraindication of pneumonectomy. Fifteen patients with pulmonary neoplasms adjacent to a fissure were studied with standard computed tomography (10 mm sections), completed by high-resolution CT. The findings of the CT studies were compared with those operative reports. On surgery, the oblique fissure was infiltrated in 12 patients, unharmed in 2 others, while the horizontal fissure was infiltrated in 3 patients. Standard CT allowed diagnosing the involvement of the oblique fissure in 4 patients. Thin sections with high-resolution reconstruction algorithms allowed detecting the involvement of the oblique fissure in 13 cases, including one false-positive result. On thin sections, the fissures appear as well-delineated, dense lines. This allows an accurate study of the relationships between the tumor and the fissure, thus increasing the sensitivity of CT for the detection of tumoral extension across the fissures. The orientation of the horizontal fissure, which is almost parallel to the plane of section, makes the study of its relationships with an adjacent mass difficult, even in high-resolution CT.
There is evidence for an impaired T cell-mediated B cell response during senescence. In thirty aged donors, pokeweed mitogen (PWM)-driven immunoglobulin (Ig) synthesis by B cells co-cultured with autologous enriched CD4+ lymphocytes and low amounts of monocytes, was evaluated. Under such experimental conditions, elderly cultures displayed a reduced IgG and/or IgM production when compared with the younger counterpart. Moreover, interleukin (IL)-2 and/or IL-5 addition to cultures led to an enhancement of Ig release. In contrast, IL-4 supplementation failed to positively modulate B cell differentiation. At the same time, aged cells cultured in the presence of IL-2 + IL-5 exhibited an increased Ig synthesis, while the addition of IL-2 + IL-4 or IL-4 + IL-5 mixtures did not induce any significant effect in comparison with homologous untreated samples. The results suggest a critical role for IL-2, IL-4 and IL-5 in the modulation of T helper cell-driven B cell polyclonal responsiveness in the elderly.
The staging of bronchogenic carcinoma is an important factor to select the appropriate treatment. Indeed, the definition of locoregional spread and of hilar and mediastinal node involvement is essential for both correct preoperative assessment and prognostic evaluation of bronchogenic carcinoma. CT and MR imaging are the methods of choice in the evaluation of T and N, even though other techniques--e.g., US and nuclear medicine--can also provide valuable diagnostic information. The authors examined 50 patients with primary bronchogenic carcinoma by means of plain radiographs, CT and MR of the chest. MR and CT findings were compared with surgical results on the basis of TNM classification. In the evaluation of T, sensitivity and specificity were 66% and 88.6%, respectively, for CT and 76% and 92% for MR imaging. No statistically significant differences were found between the two imaging methods (p = 0.19). In the evaluation of N, sensitivity and specificity were 56% and 78%, respectively, for CT and 76% and 88% for MR imaging. A statistically significant difference was found between MR and CT accuracy rates (p = 0.934). CT and MR results were in disagreement especially in the evaluation of hilar lymph nodes. To date, MR imaging cannot be considered a substitute for or a routine adjunct to CT in the staging of bronchogenic carcinoma due to its poor spatial resolution, to the presence of artifacts (especially with high-intensity fields), its cost and limited availability. However, in the evaluation of specific anatomical regions--e.g., the pulmonary apex and the peridiaphragmatic region--MR can provide more diagnostic information than CT thanks to its multiplanarity and better contrast resolution.
The authors evaluated the role of GdDTPA in magnetic resonance angiography (MRA) of intracranial vessels. Fifteen patients affected with different conditions underwent MRA of intracranial vessels before and after paramagnetic contrast medium infusion. A superconductive 1.5-T magnet (Magnetom Siemens) was used, and a head circular coil, together with the 3DFT TOF technique. The enhanced exam was performed following the infusion of 0.2 ml/kg of GdDTPA in about 2 minutes, with simultaneous MRA image acquisition. To compare enhanced with unenhanced images relative to signal intensity, the signal increase at the basilar artery and carotid sinus was studied, together with signal-to-noise (S/N) ratio and spatial resolution. During acquisition, enhanced MRA images at the basilar artery showed a mean intensity value of 423.8 +/- 33.2 vs 357.8 +/- 53.2 of unenhanced scans; a statistically significant difference (p < 0.05; p < 0.01) was observed in favor of enhanced images. At the carotid sinus, enhanced MRA showed 184.5 +/- 28.4 mean intensity value vs 190.5 +/- 19.8 of unenhanced exams; no statistically significant difference was observed (p < 0.05; p < 0.01) in favor of unenhanced exams. At the basilar artery the S/N ratio of baseline exams was 1.9 vs 2.2 for enhanced scans; at the carotid sinus S/N ratio was 2.4 (unenhanced) vs 2.3 (enhanced). Thus, MRA allowed better visualization of peripheral branches of arterial (95.6%) and venous vessels, which unenhanced scans always failed to depict; on the other hand, enhanced images exhibited poorer definition of arterial vessels which were never isolated from the background. The simultaneous visualization of arterial and venous vessels, of choroid plexus and mucosae, affect the quality of enhanced angiograms. At present, GdDTPA is the sole contrast medium suitable for MRA intracranial vessels even though, due to its pharmacokinetic features, it is not the optimum medium.
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The differential diagnosis of peripelvic cysts and hydronephrosis by means of US sometimes presents some problems; in fact, the use of urography to solve a diagnostic doubt is not uncommon. This study was aimed at demonstrating that another US sign, which we have called the "convexity" sign, can be useful in allowing peripelvic cysts to be distinguished from hydronephrosis. Thus, cysts exhibit convex walls and curved outline, whereas in hydronephrosis the walls of the dilated calices are linear. The latter feature is present in all degrees of hydronephrosis, except in severe cases. Forty-nine adult patients, a total of 98 kidneys, were examined with US and urography; 69 kidneys were found to be pathologic: 48 presented with cysts, and 21 with hydronephrosis. In addition to the new sign, the classic signs of peripelvic cysts were also considered, that is the separate areas and the non-visualization of the ureter. The sensitivity of the new sign was 97% and its specificity was 95%. The sensitivity and the specificity of the classic signs were 97% and 95%, respectively for the separated areas, and 100% and 91% for the non-visualization of the ureter. The cumulative sensitivity of the 3 signs was 99%, and their specificity 96%. Our results show how the integrated analysis of the considered signs (especially those with high specificity) is useful for the differential diagnosis, and therefore to avoid the indiscriminate use of urography.
The authors standardized the MR-venography technique in 50 patients for the study of intracranial venous circulation and identified, for each vessel and district, the best acquisitions and rotations. The possible diagnostic applications of MR-angiography were also evaluated. The examinations were performed with a 1.5-T superconductive magnet (Magnetom, Siemens) and linear head coil. Fifty subjects were examined--40 healthy volunteers, 5 patients affected with multiple sclerosis (MS) and 5 patients with pathologic conditions of intracranial venous circulation. The 40 volunteers were studied with FISP 2D techniques; in 10 of them the images were acquired on the coronal plane, in 10 on the sagittal plane, in 10 on the axial plane, and in 10 on the axial plane after a 90 degrees saturation pulse to obtain saturation of the arterial signal. The FISP 3D sequence acquired on the axial plane and after i.v. gadolinium administration was used in the study of the 5 patients affected with MS. In the post-processing all the acquired images were rotated on the axial (z), sagittal (x), and coronal (y) axes, from 0 degrees to 180 degrees with a 15 degrees step. Data correlation showed that the veins of the postero-superior group were well visualized with 2D sequences on the sagittal plane and rotated, in the post-processing, on the z axis 0 degrees-180 degrees and on the coronal axis from -45 degrees to 45 degrees. The veins of the antero-inferior group were clearly demonstrated with 2D sequences acquired on the axial plane and after arterial saturation, rotated in the post-processing on the sagittal and coronal axes from -45 degrees to 45 degrees. Small veins--i.e., veins of the scalp, diploic and emissary veins, and inferior sagittal sinus--were well visualized with 2D sequences acquired on the coronal plane an rotated during post-processing on the z and x axes 0 degrees-180 degrees following i.v. injection of gadolinium. MR-venography is a new technique which can be useful to answer such specific diagnostic questions as the staging of brain neoplasm contiguous to intracranial venous vessels, the study of arteriovenous malformations and thrombosis on intracranial venous sinuses, as it has been demonstrated in 5 pathologic cases.
Aim of this study was to determine whether pancreatic size is altered in patients suffering from type I diabetes mellitus. Twenty-five diabetics (14 males and 11 females) and twenty-five healthy controls entered the study. All patients and controls were scanned by the same operator with the same US equipment after overnight fasting. The longitudinal and antero-posterior diameters of the head, body and tail and the transverse diameter of the head as well as the total area of the gland were measured through longitudinal and axial scans. The two groups were homogeneous relative to age, sex, distribution, height, weight and body mass index. All measured diameters as well as the total area of the gland were significantly smaller in diabetic patients than in controls (1-way ANOVA: p less than 0.001). These results may open new perspectives to US identification of possible changes in pancreatic size by a new US study including high-risk subjects without clinical signs.
Severe type II essential mixed cryoglobulinemia (EMC) bears a poor prognosis. Treatment with corticosteroids and/or cytotoxic drugs infrequently results in long-term remissions, and is associated with significant toxicity. We conducted a prospective study with interferon (IFN) in 21 patients with severe type II EMC unresponsive to immunosuppressive regimens. They were treated with recombinant IFN-alpha 2a (18 patients) or with natural IFN-beta (three patients), alone, at a dosage of 3 megaunits (MU)/d for 3 months, followed by 3 MU every other day as maintenance. We observed 11 complete remissions, five partial remissions, and five minor responses. Of 16 patients observed for more than 1 year, 11 remained in remission for 14 to 40 months; five of them remained in complete remission for 18 to 40 months after withdrawal of treatment. Four patients discontinued treatment because of side effects. In four patients who relapsed while on maintenance therapy with recombinant IFN-alpha 2a, remission could be reinduced by treatment with natural IFN-alpha. The response rate of 77% achieved in this study prompts the use of IFN-alpha as a first-choice drug for type II EMC.
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Several findings point out that melanoma culture supernatants release soluble factors which modulate mononuclear cell chemotactic responsiveness. In this regard, either an enhancement or an impairment of chemotactic capacity has been found. Here, we provide evidence that supernatant recovered from human melanoma cell metastasis culture is able to trigger monocyte and polymorphonuclear cell chemotaxis. This activity is not affected by the presence of anti-IL-1 antibody during the assay. Further studies are in progress to isolate and characterize soluble factors involved in this activity.
During the last few years, several observations outline that the impaired T lymphocyte proliferative capacity in the elderly is due to a reduced interleukin 2 (IL-2) release. To further investigate the activation process during lectin stimulation, aged peripheral blood mononuclear cells (PBMC) were stimulated with phytohemagglutinin (PHA) and assessed for CD25 (IL-2 receptor) and CD71 (transferrin receptor) expression at different intervals of time. Our results provided evidence for a significant decline of both structure induction, above all in the later phase of culture. Indomethacin (INDO) treatment gave rise to an enhancement of CD71 antigen expression only, while prostaglandin E2 (PGE2) supplementation to culture media further decreased either CD25 or CD71 receptor induction. Interferon (IFN)-alpha and IFN-gamma treatment failed to modulate the frequency of CD25+ and/or CD71+ cells. Finally, the expression of CD71 receptor was increased by deferoxamine supplementation, this suggesting a partial involvement of iron overload in the depressed function. Although further studies are required to evaluate at a molecular level the decreased antigen expression, these findings indicate that several mechanism are involved in the elderly-related decline of T lymphocyte activation structures during lectin stimulation.
After making the visualization of the intracranial circulation possible without contrast media, the radiologist is now evaluating the diagnostic role of the different techniques of MRA. Attempts are also being made to characterize the main patterns of intracranial vascular diseases. The authors examined, with 3D TOF MRA, 40 patients presenting with 50 vascular lesions on MRI scans. Twenty of 40 patients were also studied with angiography. Seventeen aneurysms were detected, together with 3 stenoses of the cerebral arteries, 13 arteriovenous malformations, 12 dolichobasilar arteries, 3 postoperative and 2 post-embolization controls. MRI was performed with a superconductive magnet (1.5 T), a dedicated coil and gradient-echo 3D TOF FT sequences. The refocused sequence for flux, FISP 3DFT, required the following parameters: TR = 0.04 s, TE = 10 ms, flip angle = 15 degrees, 256 x 256 matrix, 1 acquisition. The 64-80 mm volume along the axial plane was divided so that an actual 1-mm thickness was excited. In post-processing, the maximum-intensity projection was employed on the axial plane 0 degrees-90 degrees (15 degrees interval). In the various conditions, the results obtained with MRA were correlated and compared with MRI findings. MRA provided useful additional information in 27.4% of cases in the study of aneurysms, arteriovenous malformations, vascular occlusion and dolichobasilar arteries, as well as in the follow-up of these lesions. MRA is currently suggested in the evaluation of cerebral circulation and is considered a complementary technique to MRI. MRA is also to be used preliminary to angiography.
In fourteen patients with pulmonary tuberculosis (TBC) (seven active and seven chronic cases) non-specific immunity and B cell function were evaluated. Polymorphonuclear cell (PMN) and monocyte chemotaxis, phagocytosis and killing were depressed to a different extent regardless of the disease status. Additionally, determination of lymphocyte-derived chemotactic factor and leukocyte inhibitory factor activities indicated a reduced production of these two lymphokines. This may also explain the impairment of phagocyte functions. Furthermore, the frequency of T cell subsets was slightly modified except for the increased number of CD25+ cells. The in vitro antibody response was analysed in a plaque-forming cell system using pokeweed mitogen (PWM) as a polyclonal activator and purified protein derivative (PPD) as a specific antigen. Results show that in patients with active TBC the anti-PPD antibody response was markedly enhanced, while in both groups of patients PWM-induced antibody synthesis was normal. These findings indicate several immune deficiencies related to phase activity which occur during the course of the disease.
Atheromasic lesions and other pathologic conditions of the arterial vessels of the neck are the most frequent causes of cerebrovascular disease. Diagnostic imaging currently employs digital subtraction angiography (DSA), Doppler, and color-Doppler US to study these conditions. Digital subtraction intraarterial angiography (DSAA) can provide both an early diagnosis and an accurate preoperative depiction of neck vessels; however, in spite of its effective value, it still remains an invasive technique. Magnetic Resonance angiography (angio-MR) is the latest technique allowing the depiction of neck vessels morphology. It shares with digital angiography the capability of supplying spatial depiction of all the examined vascular structures, and with US its noninvasiveness. The authors investigated angio-MR capabilities in providing accurate and detailed images of neck arteries; the images were then compared with DSA ones. Thirty patients with cerebrovascular diseases were studied. MR imaging was performed with a 1.5 T unit with a dedicated coil, and gradient-echo sequences were employed. Refocused sequences for flow were acquired on both the coronal and the sagittal planes, with the following parameters: TR 40, TE 10, flip angle 25 degrees, acquisition volumes 80-35 mm, 64-15 frames. Digital angiography demonstrated 101 vascular lesions: 27 slight stenoses (less than 30%), 19 mild stenoses (31-70%), 12 severe stenoses (71-99%), 7 occlusions, 14 coilings, 7 kinkings, and 15 hypoplasias of vertebral artery. In slight stenoses, angio-MR underestimated the condition in 11/27 patients. In mild and severe stenoses, as well as in occlusive diseases, angio-MR tended to overestimate the condition. In coiling, kinking, and hypoplasia, angio-MR yielded the same results as DSA.
In order to plan an adequate treatment, it is very important to recognize the transfissural spread of lung cancer near a pleural fissure, especially in the patients who cannot bear pneumonectomy because of impaired pulmonary function. Fifteen patients with lung cancer near a fissure were examined by means of conventional CT (10 mm-thick slices) followed by high-resolution CT (HRCT). The results obtained with both techniques were compared with surgical findings. At surgery, major fissure involvement was seen in 12 cases, minor fissure was involved in 3, and 2 patients were normal. In 4 cases fissural involvement was correctly demonstrated by conventional CT scans. Neoplastic involvement of the major fissure was identified in 13 cases by HRCT scans, with only 1 false positive. Pleural fissures appear as thin and sharp lines on HRCT scans. Thus, the relationship of lung cancers to fissures is better identified and the accuracy of the method in defining neoplastic spread is higher. However, the relationship of a neoplastic mass to the minor fissure is difficult to evaluate, because the fissure is roughly parallel to the scanning plane.
The authors report their experience with US of the hip in 1000 children aged 1 day to 8 months. US study was carried out following Graf's method. All the children were previously examined by a pediatrician, who recorded all the clinical signs on a chart. After US examination, the radiologist recorded US findings on the same chart. Thus, US findings could be compared to clinical ones: there was agreement in 71% of cases, and disagreement in the extant 29%. Furthermore, clinics exhibited a high false-negative rate (64%) and a low false-positive rate (23%). This suggests US as an useful screening method able to show early morphological and functional alterations in the infant hip. The authors also examined the incidence of the single clinical signs and risk factors, and correlated them with US findings.