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Biomedical subjects

A Romeo

Publications and source records attributed to A Romeo.

At least 37 records · Page 2Linked to original sources

Comparison of somatostatin receptor imaging, computed tomography and ultrasound in the clinical management of neuroendocrine gastro-entero-pancreatic tumours.

Neuroendocrine tumours displaying somatostatin receptors have been successfully visualised with somatostatin receptor imaging (SRI). However, there may be differences in sensitivity depending on the site of the primary tumour and/or its metastases. We studied 131 patients affected by neuroendocrine tumours of the gastro-entero-pancreatic (GEP) tract. A pathological diagnosis was obtained in 116 patients, while in 15 the diagnosis was based on instrumental results and follow-up. Fifty-one patients were examined for staging purposes, 80 were in follow-up. Images were acquired 24 and 48 h after the injection of 150-220 MBq of indium-111 pentetreotide. Whole-body and SPET images were obtained in all patients. Patients were also studied with computed tomography (CT), ultrasound (US), and other procedures. Tumours were classified according to their site of origin: pancreas n = 39, ileum n = 32, stomach n = 16, appendix n = 9, duodenum n = 5, jejunum n = 5, rectum n = 3, biliary tract n = 2, colon n = 2, caecum n = 1, liver metastases from unknown primary = 15, widespread metastases from unknown primary = 2. Sensitivity for primary tumour localisation was as follows: SRI = 62%; CT = 43%; US = 36%; other procedures = 45%. Sensitivity for liver metastases: SRI = 90%; CT = 78%; US = 88%; other procedures = 71%. Sensitivity for the detection of extrahepatic soft tissue lesions was: SRI = 90%; CT = 66%; US = 47%; other procedures = 61%. Sensitivity for the detection of the primary tumour in patients with metastases from unknown primary sites: SRI 4/17; CT 0/13; US 0/12; other procedures 1/10. In 28% of the patients SRI revealed previously unknown lesions, and in 21% it determined a modification of the scheduled therapy. Our study confirms the important role of SRI in the management of GEP tumours. However, we feel that a critical investigation should address its role in locating primary tumours, in particular in patients with metastases from unknown primary sites.

Adolescent↗

Reduced blood bcl-2 protein concentration in patients on hemodialysis.

The concentrations of bcl-2 protein that can block programmed cellular death in various cell lines were evaluated in blood samples from 10 uremic patients on hemodialysis, 10 uremics not yet on hemodialysis, and in 10 healthy controls. The bcl-2 protein variations (in uremics on dialysis) were ascertained in patients during the dialysis session. Oxidative stress was evaluated in all groups by assaying the products of intraerythrocytic lipoperoxidation. Dialyzed and nondialyzed uremic patients had higher bcl-2 protein concentrations than healthy subjects. Dialysis causes a significant reduction in the concentrations of bcl-2 protein which becomes statistically significant during the 3rd hour. In both groups of uremic patients a positive correlation was found between bcl-2 protein and products of lipoperoxidation.

Aged↗

Transcriptional remodeling and G1 arrest in dioxygen stress in Saccharomyces cerevisiae.

Saccharomyces cerevisiae, which lack a functional SOD1 gene, encoding the cytosolic Cu,Zn-superoxide dismutase (SOD1), exhibit a variety of metabolic defects in aerobic but not in anaerobic growth. We test here the hypothesis that some of these defects may be due to specific transcriptional changes programmed for cell survival under dioxygen stress. Analysis of the budding pattern and generation time showed that the slower proliferation of an sod1Delta mutant strain under air was due to an increase from 42 to 89 min spent in the G1 phase of the cell cycle. This delay in G1 was not due to an overall decline in biosynthetic activity since total protein and mRNA synthesis was not reduced even under 100% O2. However, rRNA synthesis was strongly decreased, e.g. by 80% in the mutant under 100% O2 (in comparison to N2). Under these conditions, the mutant permanently arrested in G1; this arrest was due to an inhibition of the Start function that prepares yeast for S phase. This Start arrest was due to an inhibition of transcription of the autoregulated G1 cyclins, CLN1 and CLN2; the transcription of the constitutive G1 cyclin, CLN3, was unaffected by the stress. Expression of a hyperstable Cln3 prevented the G1 arrest, indicating that it was due solely to the inhibition of cell cycle-dependent cyclin expression. This remodeling of transcription in oxidative stress was seen also in the inhibition of glucose derepression of SUC2 expression. In contrast, the signaling and activation of mating pheromone (FUS1) and copper-responsive (CUP1) promoter activity were not affected by dioxygen stress, while genes encoding other anti-oxidant enzymes (SOD2, CTT1 and CTA1) were strongly induced. The UBI loci, encoding ubiquitin, were particularly good examples of this pattern of negative and positive transcriptional response to the stress. UBI1-UBI3 expression was repressed in the mutant under 100% O2, while expression of UBI4 was strongly induced. The data demonstrate that extensive remodeling of transcription occurs in yeast under a strong dioxygen stress. This remodeling results in a pattern of expression of gene products needed for defense and repair, and suppression of activities associated with normal proliferative growth.

Cyclins↗

[Adhesion molecules. Current aspects and clinical and therapeutic perspectives].

The study about the adhesion molecules pointed out their pathogenetic role in a lot of diseases within cardiological, nephrological, oncological precincts and in a lot of infectious diseases. Their role was in fact pointed out in the ischemic heart disease and in the reperfusion damage, in the glomerulonephritis, in the tumoural metastatic processes, in the infectious and inflammatory chronic processes. The Authors considered the recent literature and emphasized the therapeutic possibilities that such an experimental approach seems to suggest.

Cardiovascular Diseases↗

Requirement of b-myb function for survival and differentiative potential of human neuroblastoma cells.

The B-myb gene belongs to a family of transcription factors that also includes A-myb and c-myb. B-myb is expressed in many cell types including human neuroblastoma cells. Here we demonstrate that B-myb expression is down-regulated during retinoic acid-induced neural and glial differentiation of neuroblastoma cells. This modulation is an early event, is maintained at late times of induction, and is in part regulated at the transcriptional level. Constitutive expression of B-myb prevents retinoic acid-induced neural differentiation as reflected by morphological features and the expression of (or lack of) biochemical markers associated with the undifferentiated phenotype. Furthermore, the expression of antisense B-myb transcripts does not allow the rescue of viable cells, suggesting an important role for B-myb in the survival of neuroblastoma cells. These results indicate that B-myb plays a functional role in the differentiative potential of neuroblastoma cells, raising the possibility that this gene is one of the nuclear regulators in the cascade of events leading to cellular differentiation.

Base Sequence↗

The combined effect of a GnRH analog in premenopause plus postmenopausal estrogen deficiency for the treatment of uterine leiomyomas in perimenopausal women.

Thirty-four perimenopausal women with uterine leiomyomas were treated with intramuscular injections of leuprolide acetate depot each 28 days for 6 cycles, and 12 of them after 168 days of no medication underwent a second 6-month therapy cycle. At the end of the observation period the expected improvement during treatment was maintained at cessation of therapy in 15 patients, due to the effect of the natural postmenopausal estrogen deficiency. Only 3 women underwent hysterectomy, due to the regrowth to baseline values of uterine size. It is concluded that the therapy with gonadotropin-releasing hormone analogs in perimenopause offers an effective alternative to surgery in the treatment of uterine leiomyomas.

Drug Administration Schedule↗

Seizure and EEG patterns in Angelman's syndrome.

We studied the seizure and polygraphic patterns of 18 patients with Angelman's syndrome. All patients showed movement problems. Eleven patients were also reported to have long-lasting periods of jerky movements. The polygraphic recording showed a myoclonic status epilepticus in nine of them. Seven patients had partial seizures with eye deviation and vomiting, similar to those of childhood occipital epilepsies. These seizures and electroencephalographic patterns suggest that Angelman's syndrome occurs in most of the patients as a nonprogressive, age-dependent myoclonic encephalopathy with a prominent occipital involvement. These findings indicate that, whereas ataxia is a constant symptom in Angelman's syndrome, the occurrence of a transient myoclonic status epilepticus may account for the recurrence of different abnormal movements, namely the jerky ones.

Adolescent↗