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Biomedical subjects

R Moretti

Publications and source records attributed to R Moretti.

At least 19 recordsLinked to original sources
PubMed1992

Marine sponge polyketide inhibitors of protein tyrosine kinase.

The marine polyketide natural product, halenaquinone, was shown to be an irreversible inhibitor of pp60v-src, the oncogenic protein tyrosine kinase encoded by the Rous sarcoma virus. This compound had an IC50 of approximately 1.5 microM against pp60v-src and also inhibited the ligand-stimulated kinase activity of the human epidermal growth factor receptor with an IC50 of approximately 19 microM. Halenaquinone blocked the proliferation of a number of cultured cell lines, including several transformed by oncogenic protein tyrosine kinases. Halenaquinol, xestoquinone, halenaquinol sulfate, and several simple synthetic quinone analogs were also shown to inhibit pp60v-src.

Animals↗
PubMed1992

A motion correction algorithm for an image realignment programme useful for sequential radionuclide renography.

The correction of organ movements in sequential radionuclide renography was done using an iterative algorithm that, by means of a set of rectangular regions of interest (ROIs), did not require any anatomical marker or manual elaboration of frames. The realignment programme here proposed is quite independent of the spatial and temporal distribution of activity and analyses the rotational movement in a simplified but reliable way. The position of the object inside a frame is evaluated by choosing the best ROI in a set of ROIs shifted 1 pixel around the central one. Statistical tests have to be ful-filled by the algorithm in order to activate the realignment procedure. Validation of the algorithm was done for different acquisition set-ups and organ movements. Results, summarized in Table 1, show that in about 90% of the simulated experiments the algorithm is able to correct the movements of the object with a maximum error less or equal to 1 pixel limit. The usefulness of the realignment programme was demonstrated with sequential radionuclide renography as a typical clinical application. The algorithm-corrected curves of a 1-year-old patient were completely different from those obtained without a motion correction procedure. The algorithm may be applicable also to other types of scintigraphic examinations, besides functional imaging in which the realignment of frames of the dynamic sequence was an intrinsic demand.

Algorithms↗
PubMed1992

Immunological and gadolinium-DTPA MRI evaluation of relapsing remitting multiple sclerosis.

The levels of lymphocytes, blood lymphocytes subsets (CD3+, CD4+, CD8+, DR+, CD25+, CD4+, CD45RA+, CD4+, CD29+ cells) and sIL-2r of 10 patients affected by relapsing-remitting multiple sclerosis were serially studied. The identification of the activity of the disease was made by gadolinium-DTPA (Gd-DTPA) MRI. The immunological determinations and the MRI of the brain and spinal cord were performed every 14th day for a period of three months. No significant difference of the immunological values were found between the presence and the absence of Gd-DTPA enhancing areas, except lymphocytes (p < 0.05). These immunological parameters, evaluated in the peripheral blood, are not a marker of disease activity in relapsing-remitting MS patients.

Adult↗
PubMed1992

Effect of Thymomodulin on luteinizing hormone, prolactin and testosterone in male rats.

The effect of Thymomodulin (TMD), a calf thymus derivative, on luteinizing hormone, prolactin and testosterone was studied in male rats after acute and chronic treatment. The results showed that the stimulatory action on prolactin and testosterone secretion after acute (prolactin) or one month chronic (testosterone) treatments completely vanished during six month chronic administration. No effect was observed on luteinizing hormone after acute or chronic treatment.

Animals↗
PubMed1992

[Results of the quality control of magnetic resonance images].

The results are reported of an image quality control performed by the Medical Physics Dept. of Spedali Civili, Brescia, Italy, after the implementation of an MR unit (Siemens-Magnetom 1.5 T) in the Radiology Department. Image quality parameters were evaluated, with the methods suggested in literature, for test objects images acquired in the conventional projections (axial, sagittal, and coronal) using RF body and head coils. Our aim was to evaluate system evolution during optimization of the equipment and to identify, when possible, eventual situations of stability and the time needed to achieve them. The results obtained for the uniformity and the signal-to-noise ratio parameters are evaluated as time curves with the analysis of linear regressions of parameters evolution over time. The measurements were made over a 14-month period, on a fortnight basis. The long-term variations are emphasized. The uniformity parameter exhibits no significant changes over time, while signal-to-noise ratio tends to increase, mostly due to noise decrease. Noise was observed to stabilize in the last months. A second analysis, with a statistical test on the difference of two subsequent measurements, was carried out to confirm this trend. Stability periods could be identified for all parameters. As for noise, in particular, a stability interval from May to October 1990 confirmed the regression results. A normality range was defined in this period as a reference for subsequent measurements.

Magnetic Resonance Imaging↗
PubMed1991

Resampling algorithms for diagnostic radiology.

The use of digital image resampling can be highly suitable for diagnostic radiology. It can be applied not only to obtain zoom effects but also to solve various problems related to the comparison of images of different origin (NMR, CT, NM). The mathematical approach to this kind of algorithm, based on rational assumptions, can be very wide and diversified. In this work the principles of the stochastic and of the analytical methods have been analyzed. In particular, a complete mathematical treatment of the integral analytical methods, which are both the most theoretically interesting and analytically complex, has been performed. The practice of these techniques has to be determined each time from the analysis of the specific problem to which they are to be applied in the routine, and after a retrospective analysis of the results obtained.

Algorithms↗
PubMed1991

Ouabain-insensitive Na-ATPase activity in homogenates from different animal tissues.

1. Two Na(+)-stimulated ATPase activities were determined in gill homogenates from squid, shrimp and teleost fish; in kidney slice homogenates from teleost fish, bullfrog, toad, iguana, chicken, duck, rat, pig and cow, as well as in homogenates from rat small intestinal cells, brain cortex and liver slices. The two Na(+)-stimulated ATPase activities, the Na- and the Na,K-ATPase, showed a different behavior toward K+ and ouabain. 2. The ouabain-insensitive, K(+)-independent, Na-ATPase activity for all the studied homogenates was completely inhibited by 2 mM furosemide. 3. An increase in cell volume of the kidney, brain cortex and liver slice preparations, as well as of the rat small intestinal cells, produced a concomitant increase of the ouabain-insensitive Na-ATPase.

Adenosine Triphosphatases↗
PubMed1991

[Evaluation of the accuracy of the study on diverse techniques of planning radiotherapy of breast tumors].

The authors report the results of the analysis of several factors contributing to the accuracy of treatment planning in the radiation therapy of breast cancer. Different techniques (non-radiological vs CT-based) were used for the acquisition of patients' data; different methods (manual vs computerized) were employed for dose calculation. As for geometric parameters describing the external outline and target volume, mean differences were lower than 4%. Switching from a completely manual method to a CT-based one with computerized calculation, a 3.56% mean decrease in the value of reference isodose (p less than 0.01) was observed, together with a 3.87% mean increase in the estimated inhomogeneity (p less than 0.001). The non-CT-based outline of target volume exhibited geographic missing of inner portions of the target in 8/16 patients. Our results demonstrate that treatment planning procedures can be a significant source of clinically relevant inaccuracy, which may affect treatment outcome and tumor control.

Breast Neoplasms↗
PubMed1990

Conservative management of temporomandibular disorders: a posttreatment comparison between patients from a university clinic and from private practice.

Long-term (1 to 7.5 years) follow-up evaluations of 110 adult patients who were seen for diagnosis and treatment of symptoms related to myofascial problems (MP), internal derangement (ID), or both were conducted by means of telephone interview. One half of the patients were seen at the Northwestern University Dental School TMJ Clinic, while the other half were seen in the private office of one author (H. T. P.). The purpose of this study was to evaluate patient response to conservative therapy combined with advice about self-management, as compared with the response to advice only. Further, we desired to compare treatment outcomes among (1) diagnostic categories ID, MP, and ID plus MP, (2) clinic patients and private patients, and (3) patients with acute disease and those with chronic disease. Chronic disease was identified as that in which pretreatment symptoms had persisted for more than 4 months. The ridit analysis was used to assess differences in outcomes for patients in the three diagnostic categories and for clinic patients compared with private patients. The results revealed no significant differences. There was a trend for patients with acute conditions to improve more than those with chronic problems; however, further research is needed to determine whether a correlation exists between symptom duration and treatment outcome. At the time of the follow-up evaluation, 88% of all patients reported substantial or total improvement in their symptoms of pain and dysfunction. Therefore, conservative therapy, including advice about self-management, was found to be both adequate and appropriate for most of these patients.

Acute Disease↗
PubMed1989

[Hemodynamic effects of the intravenous administration of captopril in patients with chronic congestive heart failure].

The aim of the present study was to evaluate the hemodynamic response to the intravenous administration of the angiotensin converting enzyme-inhibitor captopril. Plasmatic renin activity was also monitored. The study population included 10 patients with chronic congestive heart failure: 3 were in the second NYHA functional class, 5 in the third, and 2 in the fourth. The patients received a first dose of 5 mg of captopril followed, after 10 min, by a second bolus-dose of 15 mg. Hemodynamic and hormonal measurements were repeated in the following 4 hours. The greatest hemodynamic effect, considered as the time of maximal mean arterial pressure and systemic vascular resistances decrease, and cardiac index increase, was noted 20 min after the first bolus dose administration. Mean arterial pressure (MAP) decreased by 13% (p less than 0.01), mean pulmonary artery pressure (MPAP) by 14% (p less than 0.05), right atrial pressure (RAP) by 30% (NS), wedge pressure (WPP) by 23% (p less than 0.01), systemic vascular resistances (SVR) by 21% (p less than 0.05), pulmonary vascular resistances by 22% (NS); cardiac index (CI) increased by 12% (p less than 0.05), stroke volume index by 10% (NS). Heart rate didn't change. The plasmatic renin activity (PRA) increased by 339% (p less than 0.01) reaching the maximal level in concomitance with the greatest hemodynamic effect. Hemodynamic changes were already noted 5 min after the first dose and lasted up to 75 min later.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1979

The relationship between wrist-monitored motor activity and serum CPK activity in psychiatric in-patients.

Motor activity, monitored by a wrist motion transducer, was related to serum CPK activity the following morning in a group of psychiatric in-patients. In 4 of 10 patients, studied for periods exceeding one week, total 24-hour activity was significantly correlated with morning serum CPK activity. Motor activity during the night was unrelated to serum CPK activity. In a larger group of 30 patients, studied for one or two-day periods, inter-individual differences in activity level were not related to serum CPK activity, although both sex and race were significantly related to variance between subjects in that activity.

Creatine Kinase↗