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Biomedical subjects

M Riva

Publications and source records attributed to M Riva.

142 records · Page 8Linked to original sources
PubMedDate not supplied

Cloning of yeast lysyl- and phenylalanyl-tRNA synthetase genes.

Cloning of yeast lysyl- and phenylalanyl-tRNA synthetase genes was accomplished by probing a lambda gt11 recombinant DNA expression library with antibodies directed against the purified enzymes. Several DNA clones encoding either the alpha or the beta subunit of phenylalanyl-tRNA synthetase were isolated. In each case, the inserted DNA was oriented in the same direction with respect to the lambda gt11 lacZ transcription unit, giving rise to the expression of hybrid proteins. The corresponding DNA fragments constitute suitable hybridization probes for the isolation of complete nucleotide sequences encoding the alpha and beta subunits of the enzyme. Recombinant DNA lambda gt11 clones encoding lysyl-tRNA synthetase were also selected. One of these contained yeast DNA inserted with the opposite orientation with respect to lacZ. The lysogen corresponding to that recombinant DNA phage produced an active, native lysyl-tRNA synthetase. The 3.6 kbp DNA insert contained all the information necessary for the expression of yeast lysyl-tRNA synthetase in E. coli.

Amino Acyl-tRNA Synthetases↗
PubMedDate not supplied

[NMR in the diagnosis and treatment of neurologic lesions in decompression sickness].

The case of a decompression sickness in woman, diving to 26 meter depth is reported. The patient was helped by instructor's computer (error!) and she presented risk factors for embolic disease (obesity, smoke, estroprogestinic therapy). She presented with many symptoms of decompression sickness during immersion and during re-ascent (headache, vertigoes and paresthesias). She was not treated on the place of incident, but only 36 hours later at our center of hyperbaric medicine. Her Magnetic Resonance imaging showed hyperintensity lesions of white matter.

Adult↗
PubMedDate not supplied

Pathophysiology, clinical manifestations and supportive care of metastatic brain cancer.

Brain metastases (BrM) are tumours that originate in tissues outside the central nervous system and spread secondarily to involve mainly the brain. The management of patients with cerebral metastases is complex, costly, and in some instances controversial. Furthermore, even in patients with widespread systemic cancer, the symptoms of the disease are often controllable while the symptoms of the BrM may be disabling. The treatment of BrM is one of the few areas of neuro-oncology where real progress has been made in the last twenty years. Moreover, the costs of managing this disease are rising, as therapies become more intensive and the number of patients with BrM increases. Modern neuroradiological imaging techniques, which are able to discover BrM earlier in the course of systemic cancer, and the greater efficacy of specific treatments, which lengthens survival, have increased the prevalence. The aggressive treatment of BrM may add some benefits to the patient, but its excessive cost leads to the necessity for accurate cost-effectiveness analysis. The latter begins with a complete understanding of the disease: its diagnosis, natural history and results of various modalities of treatment. While the development of BrM usually indicates a poor prognosis for the patient, advances in supportive care have made it possible to reverse most of the neurological symptoms and to give patients a meaningful extension of useful life.

Brain Neoplasms↗
PubMedDate not supplied

Controversies in the management of brain metastases: the role of chemotherapy.

The role of chemotherapy (CT) for brain metastases (BrM) is still controversial. Limited life expectancy and presence of the blood-brain barrier (BBB) have been considered as contraindications for relatively aggressive therapies, such as CT. Nevertheless, more recent studies emphasise the possibility that in addition to historical nitrosoureas, also platinum derivatives, etoposide, teniposide, gemcitabine, irinotecan, topotecan and temozolomide can pass the BBB as they are active against selected BrM. Interaction of cytotoxic agents with other drugs may represent a problem in the treatment of BrM. By far, the most important factor conditioning the response to cytotoxic agents is the chemosensitivity of different tumours. CT proved to be effective in patients with BrM from lung cancer, mainly small cell lung cancer, breast cancer, choriocarcinoma and germ cell tumours. In these malignancies the responses to CT are similar to those observed in other metastatic sites. This observation, confirmed by many studies, contrasts with the theory, emphasised in the past, of the brain as a sanctuary. In fact BBB may be important in protecting normal brain tissue and micrometastases from CT, but not when BrM are symptomatic and clinically evident. The clue to the treatment of chemosensitive tumours is to assess the most active drugs and combinations. Cisplatin and etoposide was confirmed to be the treatment of choice in many situations (BrM from lung and also from breast cancer). Newer drugs are now on study: topotecan and temozolomide seem to be particularly promising (alone or in association with other drugs) in the treatment of various BrM (also from melanoma) and could represent an alternative to more widely-used drugs or as second-line treatments.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

The long-term efficacy and tolerability of carbolithium once a day: an interim analysis at 6 months.

Evidence supporting the use of lithium in the long-term care of bipolar disorder patients is unequaled; fluctuations of lithium (Li) plasma concentration, however, are associated with side effects at peak, and symptomatic states at trough, Li plasma levels. Slow release preparations represent a means of maintaining stable Li plasma levels and thereby: [1] reducing side effects, [2] requiring fewer daily administrations, [3] possibly providing more stable therapeutic response and [4] improving patient compliance. The aim of the present study is to investigate the long-term efficacy and tolerability of a new prolonged release formulation of Li, called Carbolithium Once A Day (OAD), in patient with bipolar disorder previously treated with standard Li. Upon completion, the study will last for 2 years; this paper, however, is an interim analysis of tolerability and clinical outcome of 4-month (N = 27) and 6-month (N = 15) completers. Li plasma levels and doses remained relatively stable throughout the periods of observation (days 30, 60, 120, and 180). Doses of OAD did not differ significantly from doses on prior standard Li in subjects at 4 months (681 +/- 160 and 665 +/- 154 mg/d, respectively) or 6 months (647 +/- 161 and 710 +/- 192 mg/d, respectively). Correspondingly, Li plasma levels on previous traditional Li and on OAD were not significantly different at 4-months (0.47 vs 0.46 mEq/l respectively. Wilcoxon z = 0.456, p = 0.648) or 6-months (0.47 and 0.51 mEq/l respectively, Wilcoxon z = 0.220, p = 0.826). Among 4-month completers, improvement in mania scores was significant (Wilcoxon z = 2.366, p = 0.018), but was not at 6-months. Significant reduction of scores on the Melancholia Scale was observed among both the 4 and 6-month completers (Wilcoxon z = 3.516, p < 0.001 and z = 2.521, p = 0.012, respectively). The occurrence of side effects was significantly reduced among patients switched from traditional Li. All patients declared their preference for OAD over traditional Li for its better tolerability and case of use at day 30.

Bipolar Disorder↗
PubMedDate not supplied

Colloidal gold immunostaining for the detection of platelet reactive allo- and autoantibodies. Use on fresh and frozen cells.

BACKGROUND: Fresh washed platelets are commonly used as target cells for the detection of platelet reactive antibodies. The use of stored platelets would allow a faster execution of the tests and a rapid selection of phenotyped cells. METHODS: Glass-adherent platelet monolayers were freeze stored. The antigen-antibody reaction between platelet antigens and platelet reactive allo- or autoantibodies was revealed by a modified antiglobulin test, using colloidal gold-labeled anti-human IgG. Immunogold staining (IGS) was compared with the platelet suspension immunofluorescence test (PSIFT) and with the solid-phase red cell adherence assay (SPRCA). The reactivity of fresh and freeze-stored platelets was compared. RESULTS: IGS proved to be slightly less sensitive (10%) than PSIFT and SPRCA: The results obtained with fresh and freeze-stored cells were scored identically. CONCLUSIONS: The immunogold staining assay on freeze-stored platelets seems to be a convenient technical approach for platelet serology.

Autoantibodies↗
PubMedDate not supplied

[Training individuals of the construction sector in the province of Bergamo: a shared path division and an operative proposal].

With this presentation it will be introduced the experience of the work group native of Bergamo who is taken care to plan the formation course for the professional figures of system in building. The group is formed from the greater agencies present on the territory, their work is to ensure the protection of the health and the emergency of the workers in the field of the constructions. The objective is to use the formation course in order to diffuse one culture of the emergency. In the specific one they will come to describe the various planning phases of the course of formation for employers that mean to elect himself Responsible of the Service of Prevention and Protection (RSPP).

Humans↗
PubMedDate not supplied

In vivo detection of cortical plaques by MR imaging in patients with multiple sclerosis.

BACKGROUND AND PURPOSE: In vivo detection of cortical lesions in patients with multiple sclerosis (MS) by MR imaging is hampered by several factors. Among them is the low contrast between small cortical lesions and surrounding cortical gray matter offered by present techniques. METHODS: T1-weighted 3D spoiled gradient-recalled-echo (SPGR) volumes and 2D fluid-attenuated inversion recovery (FLAIR) sequences of 22 patients with MS who had 12 monthly brain MR imaging examinations at 1.5T, using a quadrature head coil, were retrospectively analyzed. These serial studies were coregistered and averaged to generate a single high signal-to-noise ratio (SNR) mean image, which was used to identify cortical lesions. The means of 12 FLAIRs and SPGRs from 14 age- and sex-matched healthy volunteers were analyzed as well. RESULTS: No cortical lesions were found on images of healthy subjects. Eighty-six cortical lesions were identified in 13 (59.1%) patients, predominantly in the frontal lobe (73.3%); 23.3% of cortical lesions lay entirely in the cortex, whereas the remaining lesions invaded the white matter underneath. CONCLUSION: Averaging multiple SPGRs created a single high SNR volume, allowing identification of cortical lesions. Because data were obtained monthly for 1 year, the average image does not account for transient lesion activity. However, for cortical lesions that remained stable during this time, the findings are valid in demonstrating the importance of high SNR images for detecting cortical brain abnormalities in MS.

Adult↗
PubMedDate not supplied

Prognostic relevance of hormonal and kinetic parameters in CNS neoplasms.

With the present study we investigated both the presence of cytoplasmic estrogen (E-Rc) and progesterone (P-Rc) receptor, nuclear E-R (E-Rn) and the percentage of cycling tumor cells with Ki-67 MAB in 32 CNS tumor specimens. The main purpose of our study was to evaluate a possible correlation between the hormonal and kinetic parameters and the clinical and neuroradiological follow-up.

Adolescent↗
PubMedDate not supplied

[Central pontine myelinolysis as potential complication of cerebellar astrocytoma: report of a case].

Central pontine myelinolysis (CPM), a rare condition first observed by Adams et al. in 1959 in a group of malnourished chronic alcoholic subjects, has subsequently been seen in patients treated with thiazide diuretics, patients hyperhydrated postoperatively, and in other clinical situations. it is characterized by quadriplegia and pseudobulbar palsy which sometimes evolves into a locked-in syndrome. The rapid correction of severe hyponatremia (> 12 mmol/L/24 h) seems to be the causal factor, with consequent osmotic edema in the richly vascularized white matter of the pons as the proposed pathogenetic mechanism. We describe the case of a chronic psychotic man with nutritional disorders and inappropriate water intake who came to our attention for a clinical picture of CPM. Neuroradiological findings and postmortem studies revealed a slow-growing cerebellar astrocytoma in addition to the typical features of CPM. We discuss the hypothesis that damage to the nervous pathways and centers involved in water and electrolyte regulation could be the causal factor of CPM pathogenesis in this case.

Astrocytoma↗