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Biomedical subjects

G Baroni

Publications and source records attributed to G Baroni.

At least 55 records · Page 3Linked to original sources

[Early diagnosis of prostatic carcinoma by random biopsies in 60 patients clinically negative but with PSA greater than 8.9 ng/ml].

60 patients, 64 years old on average, with no evidences of prostatic cancer, but with a PSA level greater than 8.9 ng/ml, have undergone six transrectal systematic sextant biopsies. All patients had no suspicious finding on digital rectal examination. Ultrasound transrectal examinations did not show hypoechoic areas suspected of a prostatic cancer. We used an automatic biopsy gun fitted with an 18 gauge biopsy needle. Three biopsies in each lobe, at the apex, in the midline zone and at the base of the prostate, in the parasaggital plane, was performed. No complications were found during following days. Of the 60 men, with a non suspicious prostate on rectal examination, 12 had prostatic cancer. They had, on average, a PSA level of 10.8 ng/ml. The PSAD level was, on average, of 0.18 and the Gleason score was, on average, of 3.8. The patients who underwent pelvic lymphadenectomy and radical prostatectomy did not have an infiltration of the glans capsule of seminal vesicles and no lymph node metastasis were found. In our study, the digital rectal and ultrasound examination alone would have missed the 23% of prostatic cancers. Therefore, according to the literature, the PSA makes us able to discover prostatic cancer more than the clinical and instrumental evaluation alone. Furthermore the ultrasound examination presents some diagnostic limits. Particularly it is very difficult to detect small cancer arising into the hypoechoic multinodular adenoma of the transition zone. In addition 10-20% of cancers, arising into the peripheral zone, are hysoechoic with the surrounding parenchyma. For that reason, when PSA value is greater then 8.9 ng/ml without clinical or ultrasound evidence of cancer, we recommend to perform six systematic sextant biopsies. At present, the real question is to determine whether this early diagnosis is useful for patients, because there is no certainty of the therapeutic benefit in terms of quantity and quality life.

Adenocarcinoma↗

[The reactive and/or repair role of the smooth muscle cells in Horton's arteritis].

A recent view of atherosclerosis indicates vascular smooth muscle cell proliferation not only as a response-to-injury but also as an essential reparative process leading to plaque stabilization. To assess the role of vascular smooth muscle cell in vasculitides we studied, as a model, 10 cases of Horton's arteritis. In particular, we investigated by immunohistochemical analysis cellular population and proliferation rate in the intimal layer. As in atherosclerotic plaques, intimal thickening in arteritis is essentially due to proliferation and migration of vascular smooth muscle cells. We suppose that, whatever the vascular disease, intimal hyperplasia contributes to stability of the vessel's wall; however the reactive/reparative process is extremely slow in spontaneous atherosclerosis, accelerated in arteritis.

Aged↗

Optoelectronic techniques for patient repositioning in radiotherapy.

In modern radiotherapy practice, patient mispositionings and movements at therapy units are considered one of the major source of error in the irradiation and, consequently, a decisive factor in relapse rate and in radiation damages occurrence. Movement analysis system ELITE has been used to carry out a new conceived control on patient repositioning procedure and to implement an automatic correction of the detected position errors. Two marker disposition models have been defined for the supine position with reliable and easily identifiable body landmarks. Analytical comparison between current and reference 3D co-ordinates of these points has constituted the core of the whole method. The detection of patient's breathing phases has allowed to synchronize the co-ordinates calculation to patient's FRC, increasing accuracy and reliability of the comparison. Results point out the relative accuracy of the commonly adopted optical laser repositioning systems and confirm the significant role that ELITE can have in radiotherapy, in order to reach a suitable tradeoff between a quick irradiation set-up and a clinically correct patient irradiation.

Least-Squares Analysis↗

A new method for placental/cord blood processing in the collection bag. I. Analysis of factors involved in red blood cell removal.

We describe a new procedure for large-scale CB processing in the collection bag, thus minimizing the risk of CB contamination. A solution of 6% hydroxyethyl starch (HES) was added directly to the CB containing bag. After RBC sedimentation at 4 degrees C, the WBC-rich supernatant was collected in a satellite bag and centrifuged. After supernatant removal, the cell pellet was resuspended and the percent recovery of total WBC, CD34+ progenitor cells, CFU-GM and cobblestone area-forming cells (CAFC) evaluated. Results obtained with three different types of CB collection bags (300, 600 and 1000 ml) were analyzed and compared with those of an open system in 50 ml tubes. CB processing procedures in 300 and 1000 ml bags were associated with better WBC, CFU, CD34+ cell and CAFC recovery (83-93%). This novel CB processing procedure appears to be easy, effective and particularly suitable for large-scale banking under GMP conditions.

Blood Component Removal↗

Detection of Epstein-Barr virus genome in sinonasal undifferentiated carcinoma by use of in situ hybridization.

Associations between Epstein-Barr virus and undifferentiated carcinomas of nasopharynx, parotid gland, and thymus have recently been reported. Epstein-Barr virus has also been associated with malignant lymphoma of the nose and paranasal sinuses. These findings raise the possibility that Epstein-Barr virus may additionally be linked to undifferentiated carcinoma of the nose and paranasal sinuses (SNUC), an uncommon but distinctive and highly aggressive neoplasm. Histologically, SNUC consists of small and medium cells, the precise characterization of which often requires immunocytochemical analysis. This study investigates the presence of DNA sequences of Epstein-Barr virus in biopsy specimens of 13 cases of SNUC that were defined immunocytochemically by use of previously reported criteria. In situ hybridization was used to detect Epstein-Barr virus genome in different cell types in routinely processed, paraffin-embedded tissues. Epstein-Barr virus-specific DNA sequences were detected in tumor cells of SNUC specimens from 5 of the 13 cases examined. No correlation was found between positive hybridization and primary tumor site, morphologic subtype, or disease course. Epstein-Barr virus DNA was detected in 38% (5 of 13) of the SNUC samples analyzed. This finding suggests that this virus may play a role in the pathogenesis of this rare neoplasm.

Adult↗

Unusual clinical aspects of oral non-Hodgkin lymphomas in patients with HIV infection.

Patients with HIV infection are at greater risk of developing malignancies. We report two HIV-seropositive patients with primary oral manifestation of a B-cell non-Hodgkin lymphoma (NHL). Localisations of tumours were the palate, with an unusual bifocal origin, and the tongue which is rarely the primary site of NHL. Ulcerations and extensive tissue necrosis were observed. Histologically both cases were high grade malignant lymphomas, immunoblastic. Epstein-Barr virus DNA was detected with in situ hybridisation in 1 patient.

Adult↗

[Expression of p53 in the skin in systemic sclerosis. Immunohistochemical study of 8 cases].

P53 gene belongs to the family of "Tumor suppressor gene". It encodes a nuclear phosphoprotein involved in cell proliferation control; mutations of p53 gene are the most common genetic alterations found in human tumors. These mutations may cause the production of an altered protein that usually loses its physiological function. The mutant p53 protein is more stable than the wild type form and it is immunohistochemically detectable. Systemic Sclerosis is characterized by activation of fibroblasts, endotheliocytes and lymphocytes; furthermore, in this disease, a proto-oncogenic activation has already been shown in fibroblasts and lymphocytes. The aim of this study was to verify p53 expression in the skin of SSc patients. Eight patients, all classified in the limited cutaneous subset of SSc, after informed consent, underwent skin biopsies of the affected and apparently unaffected skin. P53 was investigated by immunohistochemistry, using a monoclonal anti-p53 antibody (DO-7), on formalin fixed, paraffin embedded tissue. P53 immunoreactive cells were found in 4 out of 8 biopsies; in all cases the positivity was confined to cells of the basal layer of the epidermis, histologically identified as keratinocytes. A large case series and a molecular biology approach are needed to support these preliminary observations.

Adult↗

HPV and p53 in urinary bladder carcinoma.

We report a study on human papilloma virus (HPV) and p53 protein in 18 cases of urothelial carcinoma grade 1, 2 and 3. The presence of HPV has been correlated to the p53 protein expression, as this virus, once integrated in the cell nuclei, seems to cause the alteration of some genes expression, involved in the cell-cycle regulation, like p53. One case of urothelial papillary carcinoma grade 2, infiltrating the lamina propria, resulted to be positive for HPV type 31/33/51 and for p53 protein. Our data suggest that HPV type 31/33/51 may have played a role in the pathogenesis of this neoplasia causing an alteration of p53 gene.

Aged↗

[Intraerythrocytic potassium and diuretic therapy].

Diuretic-induced hypokalemia is one of the most common and important disturbances during antihypertensive therapy. However, it has been suggested that determination of serum potassium levels may not reflect significant changes of its intracellular concentration. This study was performed to evaluate whether there is any change of red cell potassium concentration as compared to serum potassium levels, in ten patients receiving chlorthalidone, 25 mg/day, during 4 weeks. Significant antihypertensive effect was achieved and despite serum potassium levels less than 3.5 mEq/1 occurred in four patients, no significant change in intracellular concentration of potassium was observed in this population with essential hypertension.

Adult↗

Abnormal cardiovascular reflexes in juvenile diabetics as preclinical signs of autonomic neuropathy.

The prevalence of abnormalities of cardiovascular reflexes as a marker of autonomic neuropathy was studied in a group of juvenile diabetics with long-standing disease, aged 20-58 years (mean 36). No patient had clinical evidence of autonomic failure. The study was carried out employing the most simple techniques and routine equipment. Resting heart rate, beta-to-beat variation, Valsalva ratio, systolic blood pressure in supine position and immediately after standing were measured. The results were compared with those determined in an age and sex-matched population. Beat-to-beat variation test appeared to be the most sensitive technique in detecting an impaired autonomic function (12/54 = 22.2%). Resting tachycardia was found in 10 patients and postural hypotension in 6. Only 1 patient had an abnormal Valsalva ratio associated with postural hypotension and reduced beta-to-beat variation. In agreement with previous studies our data confirm that autonomic dysfunction is frequent in asymptomatic diabetics. The methods to detect these abnormalities are easy to perform. Therefore they may be routinely used as screening tests in the diabetic population.

Adult↗

Evaluation of theories of complex movement planning in different levels of gravity.

Due to high redundancy of degrees of freedom in the human body, we can perform any movement, from the simplest to the most complex, in many different ways. Several studies are still trying to identify the motor strategies that master this redundancy and generate the movements whose characteristics are highly stereotyped. The aim of this work is to build a simulator that is able to evaluate different motor planning hypotheses. The most interesting applications of this tool occur in studies of the motor strategy in microgravity conditions. The comparison between simulated movements and kinematics data recorded both on Earth, and during a 5-month mission on board the Mir station shows that for a complex whole-body movement (such as trunk bending) a single planning criterion cannot explain all movement aspects. However, the simulator allows an understanding of the motor planning adaptation of astronauts. In space, the lack of equilibrium constraint (which on Earth brings about the center of mass control) leads to a new motor strategy that minimizes dynamic interactions with the floor.

Adaptation, Physiological↗

Motor coordination in weightless conditions revealed by long-term microgravity adaptation.

The functional approach to studying human motor systems attempts to give a better understanding of the processes behind planning movements and their coordinated performance by relying on weightlessness as a particularly enlightening experimental condition. Indeed, quantitative monitoring of sensorimotor adaptation of subjects exposed to weightlessness outlines the functional role of gravity in motor and postural organization. The recent accessibility of the MIR Space Station has allowed for the first time experimental quantitative kinematic analysis of long-term sensorimotor and postural adaptation to the weightless environment though opto-electronic techniques. In the frame of the EUROMIR'95 Mission, two protocols of voluntary posture perturbation (erect posture, EP; forward trunk bending, FTB) were carried out during four months of microgravity exposure. Results show that postural strategies for quasistatic body orientation in weightlessness are based on the alignment of geometrical body axes (head and trunk) along external references. A proper whole body positioning appears to be recovered only after months of microgravity exposure. By contrast, typically, terrestrial strategies of co-ordination between movement and posture are promptly restored and used when performing motor activities in the weightless environment. This result is explained under the assumption that there may be different sensorimotor integration processes for static and dynamic postural function and that the organisation of coordinated movement might rely stably on egocentric references and kinematics synergies for motor control.

Adaptation, Physiological↗

Quantitative analysis of motion control in long term microgravity.

In the frame of the 179-days EUROMIR '95 space mission, two in-flight experiments have foreseen quantitative three-dimensional human movement analysis in microgravity. For this aim, a space qualified opto-electronic motion analyser based on passive markers has been installed onboard the Russian Space Station MIR and 8 in flight sessions have been performed. Techhology and method for the collection of kinematics data are described, evaluating the accuracy in three-dimensional marker localisation. Results confirm the suitability of opto-electronic technology for quantitative human motion analysis on orbital modules and raise a set of "lessons learned", leading to the improvement of motion analyser performance with a contemporary swiftness of the on-board operations. Among the experimental program of T4, results of three voluntary posture perturbation protocols are described. The analysis suggests that a short term reinterpretation of proprioceptive information and re-calibration of sensorimotor mechanisms seem to end within the first weeks of flight, while a continuous long term adaptation process allows the refinement of motor performance, in the frame of never abandoned terrestrial strategies.

Adaptation, Physiological↗