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S Greco

Publications and source records attributed to S Greco.

At least 55 records · Page 3Linked to original sources
PubMed1999

Intron retention may regulate expression of Epstein-Barr virus nuclear antigen 3 family genes.

The nuclear antigen 3 family genes (EBNA-3, EBNA-4, and EBNA-6) of Epstein-Barr virus (EBV) are important for EBV-induced immortalization and survival of B lymphocytes. However, little is known about how the expression of these genes is regulated. Each of the EBNA-3, EBNA-4, and EBNA-6 genes consists of two exons separated by a small intron. Reverse transcriptase PCR assays revealed that the vast majority of the EBNA-3, EBNA-4, and EBNA-6 mRNA, expressed in transfected and EBV-infected B cells, retained intron sequences. Northern blot and S1 protection assays confirmed that most of the EBNA-3 mRNA contained intron. Examination of deletion mutants of EBNA-3 indicated that the EBNA-3 protein was not necessary for intron retention and that there was no splicing silencing element encoded in the EBNA-3 mRNA. Cell fractionation and RNA gradient analysis revealed that the unspliced EBNA 3 family mRNAs were transported into the cytoplasm and associated with the polysomes. However, Western blot analysis of FLAG-epitope tagged EBNA-3 gave no indication of the presence of splice variant protein forms of EBNA-3. In contrast, transiently transfected cells expressing EBNA-3 revealed a sixfold increase in EBNA-3 protein expression from the genomic EBNA-3 gene compared to EBNA-3 cDNA. These data show that the intronic sequences can influence EBNA-3 protein expression and suggest that intron retention may provide a means for the fine-tuning of expression of the individual EBNA 3 family genes.

Alternative Splicing↗
PubMed1999

alpha1-adrenergic receptor subtypes in human peripheral blood lymphocytes.

We investigated the expression of alpha1-adrenergic receptor subtypes in intact human peripheral blood lymphocytes using reverse transcription-polymerase chain reaction (RT-PCR) and radioligand binding assay techniques combined with antibodies against the three subtypes of alpha1-adrenergic receptors (alpha1A, alpha1B, and alpha1D). RT-PCR amplified in peripheral blood lymphocytes a 348-bp alpha1A-adrenergic receptor fragment, a 689-bp alpha1B-adrenergic receptor fragment, and a 540-bp alpha1D-adrenergic receptor fragment. Radioligand binding assay with [3H]prazosin as radioligand revealed a high-affinity binding with a dissociation constant value of 0. 65+/-0.05 nmol/L and a maximum density of binding sites of 175. 3+/-20.5 fmol/10(6) cells. The pharmacological profile of [3H]prazosin binding to human peripheral blood lymphocytes was consistent with the labeling of alpha1-adrenergic receptors. Antibodies against alpha1A-, alpha1B-, and alpha1D-receptor subtypes decreased [3H]prazosin binding to a different extent. This indicates that human peripheral blood lymphocytes express the three alpha1-adrenergic receptor subtypes. Of the three different alpha1-adrenergic receptor subtypes, the alpha1B is the most represented and the alpha1D, the least. Future studies should clarify the functional relevance of alpha1-adrenergic receptors expressed by peripheral blood lymphocytes. The identification of these sites may represent a step for evaluating whether they represent a marker of alpha1-adrenergic receptors in cardiovascular disorders or for assessing responses to drug treatment on these receptors.

Adrenergic alpha-1 Receptor Antagonists↗
PubMed1998

Labeling of dopamine D3 and D4 receptor subtypes in human peripheral blood lymphocytes with [3H]7-OH-DPAT: a combined radioligand binding assay and immunochemical study.

Molecular biology studies have demonstrated that human peripheral blood lymphocytes express dopamine D2-like receptors belonging to the D3 and D4 receptor subtypes, whereas the characterization of these receptors using radioligand binding assay techniques provided conflicting results. The preferential dopamine D3 receptor agonist [3H]7-hydroxy-N, N-di-n-propyl-2-aminotetralin ([3H]7-OH-DPAT) was used recently for labeling lymphocyte dopamine D3 receptor. However, the selectivity of this compound for the D3 receptor was questioned. In this study we have investigated human peripheral blood lymphocyte dopamine receptor subtypes labeled by [3H]7-OH-DPAT using a conventional radioligand binding assay technique and antibodies against dopamine D2-like receptor subtypes. [3H]7-OH-DPAT was specifically bound to intact human peripheral blood lymphocytes with a dissociation constant (Kd) value of 0.32 + 0.03 nM and a maximum density of binding sites (Bmax) of 18.2 + 0.8 fmol/2 x 10(6) cells. [3H]7-OH-DPAT binding was unaffected by antibodies against dopamine D2 and D2S receptors. Anti-dopamine D3 and D4 receptor antibodies reduced [3H]7-OH-DPAT binding by about 53% and 32% respectively. Combination of anti D3 and D4 receptor antibodies reduced remarkably [3H]7-OH-DPAT binding. The above results suggest that the dopamine receptor agonist [3H]7-OH-DPAT labels dopamine D3 and D4 receptor subtypes in human peripheral blood lymphocytes. The use of antibodies raised against dopamine receptor subtypes in combination with radioligand binding assay may contribute to define receptor subtypes expressed by human peripheral blood lymphocytes in health and disease.

Adult↗
PubMed1998

Monitoring carcinoembryonic antigen in colorectal cancer: is it still useful?

The results of a study conducted to determine the usefulness of carcinoembryonic antigen (CEA) monitoring in the follow-up of patients with resected colorectal cancer are reported herein. The subjects of this study were 125 patients in whom CEA had been determined preoperatively and 239 patients in whom CEA had been monitored postoperatively. The results revealed increased preoperative CEA in only 24% of the subjects, and that this increment was correlated with subsequent more advanced tumor stage and a higher recurrence rate (P < 0.01). The postoperative CEA level exceeded the threshold in 71% of the patients affected by recurrence, 94.4% of whom developed liver metastases and 50%, nonhepatic recurrence. This marker showed elevated sensitivity for liver metastases (99%), whereas the sensitivity was lower for nonhepatic recurrence of the disease (94%). Thus, we concluded that CEA monitoring can be useful for preoperative colorectal tumor grading, even if its validity in the early diagnosis of recurrence is problematic, especially in terms of radical repeated surgery and survival.

Biomarkers, Tumor↗
PubMed1998

Adult acute upper respiratory tract infections in Sicily: pattern of antibiotic drug prescription in primary care.

We performed an observational study of the antibiotic-prescribing behaviour of Sicilian general practitioners (GPs) in managing acute upper respiratory tract infections (URTIs). Seventy-six GPs from 25 towns, representing a patient population of 96,630, participated in the study between September 1995 and May 1996. These physicians issued 2038 antibiotic treatment courses for acute upper respiratory tract infections: 792 for acute pharyngitis, 531 for acute tonsillitis, 304 for acute laryngitis and tracheitis, 268 for suppurative and non-suppurative acute otitis media, 124 for acute sinusitis and 19 for acute rhinitis. Forty-nine different antibiotics were prescribed. The most commonly used therapeutic groups were macrolides (38.6%), cephalosporins (27.1%), a combination of penicillins with beta-lactamase inhibitors (15.7%) and extended spectrum penicillins (13.5%). For each of the above diseases, except rhinitis, more than 30 different antibiotics were used. The choice of the route of administration appeared to be influenced by the age of the patients and, significantly, by a subjective clinical assessment of disease severity rather than by any consideration of epidemiological information or evidence from clinical trials. The rather marked variation in antibiotic-prescribing pattern for URTIs among Sicilian GPs reflects lack of availability or knowledge of any local or national guidelines.

Adolescent↗
PubMed1998

Role of insulin and nutritional factors in intestinal glycoprotein fucosylation during postnatal development.

This study deals with the role of insulin in the regulation of the intestinal glycoprotein fucosylation process during postnatal development in the rat. Circulating insulin level was found to increase at weaning time in parallel with alpha-1, 2-fucosyltransferase activity and with the appearance of alpha-1, 2-fucoproteins in brush-border membranes. Insulin treatment of young suckling rats induced a precocious increase in fucosyltransferase activity and in the biosynthesis of its substrate (GDP-fucose), but the sensitivity to insulin disappeared after weaning. The insulin level was lower in 22-day-old rats that received prolonged nursing (on a high-fat diet) compared with age-matched normally weaned rats (on a high-carbohydrate diet), whereas the appearance of alpha-1, 2-fucoproteins and the increase in activity of alpha-1, 2-fucosyltransferase were delayed, as was the decrease in the degradation of GDP-fucose. In 22-day-old animals that received prolonged nursing and insulin treatment, the alpha-1, 2-fucosyltransferase activity reached a level close to that observed in age-matched weaned rats, and several alpha-1,2-fucoproteins appeared in brush-border membranes with a molecular mass similar to that found in weaned rats. These results suggest that changes in insulin levels at weaning time (as caused, in the present case, by dietary modifications) may be responsible for the regulation of the glycoprotein fucosylation process, essentially by increasing fucosyltransferase activity.

Aging↗
PubMed1997

Age-related changes of the noradrenergic innervation of rat tracheo-bronchial tree and pulmonary vasculature.

Age-related changes of the noradrenergic innervation of the tracheo-bronchial tree and of pulmonary vasculature were investigated in male Wistar rats of 3 months (young), 12 months (adult) and 24 months (old/aged), using catecholamine histofluorescence techniques associated with image analysis and by high pressure liquid chromagraphy with electrochemical detection. In young rats, blue-green fluorescent nerve fibres supply tracheo-bronchial smooth muscle and tracheal and bronchial glands, which are innervated by a delicate network of nerve fibres rich in varicosities. Pulmonary artery and vein are sparsely innervated. They are supplied with nerve fibres distributed in the vasa vasorum or the adventitia and the outer tunica media. The higher noradrenaline concentrations were found in the trachea and extraparenchymal bronchi, followed by pulmonary vein and pulmonary artery. The density and pattern of noradrenergic innervation of the tracheo-bronchial tree, or of the pulmonary vasculature, were similar in young and adult rats. In aged rats, a loss of noradrenergic innervation involving primarily the supply to the smooth muscle of the tracheo-bronchial tree was observed. Histofluorescence techniques demonstrated a higher sensitivity than noradrenaline assay in detecting changes of the sympathetic innervation of the tracheo-bronchial tree and of the pulmonary vasculature. The possible significance of reduced noradrenergic innervation of the tracheo-bronchial tree in aged rats is discussed.

Adrenergic alpha-Agonists↗
PubMed1997

Evaluation of response to chemotherapy in patients affected with non-small cell lung cancer by means of three tumour markers elaborated by discriminant analysis.

Chemotherapy is the most effective treatment for inoperable patients (70%) affected with non-small cell lung cancer (NSCLC). The early detection of tumour progression is mandative in order to promptly shift these patients towards salvage or supportive therapy. The present authors investigated the clinical value of a panel of tumour markers, elaborated by means of discriminant analysis, as a follow-up indicator for the detection of tumour progression. The serum levels of tissue polypeptide antigen (TPA), CYFRA-21.1, neuron-specific enolase (NSE) and carcino-embryonic antigen (CEA) were determined before chemotherapy and after three cycles of treatment. Discriminant analysis generated a formula (canonic variable) which correctly classified the 87.8% of the 74 subjects (86.1% of the 36 progressive diseases and 89.5% of 38 non-progressive diseases). This approach produces an algorithm able to calculate a progression score in NSCLC patients which can be helpful for following-up care and therapy control of these patients.

Adult↗
PubMed1997

Validation of an algorithm able to differentiate small-cell lung cancer (SCLC) from non-small-cell lung cancer (NSCLC) patients by means of a tumour marker panel: analysis of the errors.

By means of a mathematical score previously generated by discriminant analysis on 90 lung cancer patients, a new and larger group of 261 subjects [209 with non-small-cell lung cancer (NSCLC) and 52 with small-cell lung cancer (SCLC)] was analysed to confirm the ability of the method to distinguish between these two types of cancers. The score, which included the serum neuron-specific enolase (NSE) and CYFRA-21.1 levels, permitted correct classification of 93% of the patients. When the misclassifications were analysed in detail, the most frequent errors were associated with limited disease SCLC with low NSE levels and with advanced NSCLC with high NSE levels. This demonstrates the importance of the marker in correctly categorizing patients.

Adult↗
PubMed1997

[Recurring duodenal ulcer. Evaluation of previous complications as a predictive factor of ulcer recurrence after eradication of Helicobacter pylori].

Duodenal ulcer is a chronic disease, punctuated by acute relapses. The pathogenic mechanism in 90-100% of cases is infection by Helicobacter pylori. Two major strains exist of this bacterium: I strain, which secretes a vacuolating cytotoxin (Vac-A), and another protein named cytotoxin-associated (Cag-A) and type II strain, unable to produce both proteins and unable to produce duodenal pathology. We sought to identify the natural history of relapsing duodenal ulcer after cure of the bacterial infection. In particular, we followed the outcome of patients who repeatedly had bled from their recurrent ulcer disease, after success in eliminating the microorganism from the stomach. None of 12 repeated bleeders had an ulcer recurrence after the cure of Helicobacter pylori infection. Only 3 (5%) of 60 frequent relapser had a new episode of duodenal ulcer during a follow-up reinfection by Helicobacter pylori. We demonstrated that the cure of bacterial infection is also the cure of duodenal ulcer recurrence, but for a few cases, in the latter, event one could hypothesize a defect in the production of growth factors (Epidermal Growth Factor, Fibroblast Growth Factor) or of cellular polyamines synthesis. It is important to improve the diagnosis of reinfection by implementing the urea breath test.

English Abstract↗
PubMed1997

Cervical epidural abscess: serial MRI study.

Cervical epidural abscess (CEA) at first often goes unrecognized and it is to be suspected in patients suffering by spinal ache, root pain, neurological deficit and fever. Staphylococcus aureus is the most frequent etiologic agent. At present MRI is the study of choice for the diagnosis of CEA. We suggest a serial MRI study in close time in at first doubtful cases of CEA. When the responsible organism is not identified and there are also compressive signs of the spinal cord, the treatment of choice is surgical decompression followed by selective antibiotic therapy. The duration of antibiotic therapy may be established not only by clinical judgement, but also by serial MRI study, which gives direct information about disease evolution.

Abscess↗
PubMed1996

Carcinoembryonic antigen, tissue polypeptide antigen and neuron-specific enolase pleural levels used to classify small-cell and non-small-cell lung cancer patients by discriminant analysis.

The classification of lung cancer into small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) is essential for disease prognosis and treatment. For this purpose, we have tried to optimize the use of three tumour markers determined on pleural effusions, to differentiate SCLC from NSCLC by means of a canonic variable, generated by discriminant analysis, including subjects with histologically proven lung cancer. Discriminant analysis was performed by using carcinoembryonic antigen, neuron-specific enolase and tissue polypeptide antigen pleural levels, determined in 65 consecutive and unselected patients, histologically classified as 49 NSCLC and 16 SCLC. To validate the formula generated, a control group of 37 lung cancer patients (10 SCLC and 27 NSCLC), enrolled subsequently, was employed. Applying the discriminant analysis to SCLC and NSCLC patients a good classification was obtained (92% rate of correct classification). The aforementioned formula, applied to the validation group, showed a 92% rate of correct classification. This method, which is rapid, inexpensive and routinely applicable to malignant pleural effusions, may be reliably used to classify lung cancer patients.

Adult↗
PubMed1994

Relationships between tamoxifen binding proteins in primary breast cancer biopsies.

Using high-resolution isoelectric focusing gel electrophoresis (IEF), two tamoxifen binding sites (TBS) with isoelectric point (pI) values of 4.5 and 4.3 were identified, with different affinities for tamoxifen. The form at pI 4.3 (HTBS) displayed high affinity for the ligand (kD approximately 5 nM), while the protein at pI 4.5 (LTBS) had lower affinity (kD approximately 50 nM). LTBS was found in the microsomal fraction and HTBS in the cytosol. Of a total of 319 tumours studied, 257 were oestrogen receptor (ER) positive and 106 HTBS positive. In this combined group, thus able to bind tamoxifen either through the presence of ER or HTBS (or both), ER and PR were both negatively correlated with HTBS (P < 0.0001). The oestrogen-induced protein pS2 was assayed in 92 of the 319 tumours, and was also negatively (P < 0.0001) correlated with HTBS. The levels of HTBS were similar between infiltrating ductal carcinomas without special features (NOS) and non-NOS forms. However, HTBS concentrations were significantly higher in poorly differentiated grade 3 carcinomas than grade 2 (P < 0.05) and grade 1 (P < 0.01) forms. Conversely, ER concentration was lower in grade 3 than grade 1 forms (P < 0.05). Both the relationship between high affinity TBS and ER and the high concentration of HTBS in ER-poor grade 3 carcinomas may have a bearing on the known variability of tumour response to endocrine therapy and prognosis.

Adult↗
PubMed1993

p53 associated with cathepsin D in primary breast cancer.

The p53 protein was identified in primary breast carcinomas by specific binding of PAb1801 and PAb240 antibodies. Using sodium dodecyl sulfate electrophoresis followed by immunoblotting on nitrocellulose membrane, the p53 protein was identified in 36 nuclear fractions obtained from 60 primary breast cancers; semiquantitation of p53 was performed by densitometric scanning. The total cathepsin D content, the estrogen and progesterone receptor concentration values and the axillary lymph node involvement were also assessed. Tumors expressing p53 had significantly higher levels of cathepsin D than those in which p53 was undetectable. p53 expression was strongly associated with low or negative estrogen receptor values; progesterone receptor concentrations were also significantly higher in p53-negative tumors than in those tumors with detectable p53 levels. Finally, a significant relationship between p53 expression and lymph node metastasis was observed. It was concluded that a positive association between p53 and cathepsin D values exists which is of prognostic interest in that both cathepsin D and p53 are associated with a high tumor grade and metastatic activity.

Breast Neoplasms↗
PubMed1993

Magnetic resonance imaging in cervical spinal cord compression.

In patients with cervical spondylotic myelopathy MRI sometimes shows increased signal intensity zones on the T2-weighted images. It has been suggested that these findings carry prognostic significance. We studied 56 subjects with cervical spinal cord compression. Twelve patients showed an increased signal intensity (21.4%) and a prevalence of narrowing of the AP-diameter (62% vs 24%). Furthermore, in this group, there was evidence of a longer mean duration of the symptoms and, in most of the patients, of more serious clinical conditions. The importance of these predisposing factors remains, however, to be clarified since they are also present in some patients without the increased signal intensity.

Adult↗