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Biomedical subjects

M Brunetti

Publications and source records attributed to M Brunetti.

At least 55 records · Page 3Linked to original sources
PubMed1997

Characterization of engineered hepatitis C virus NS3 protease inhibitors affinity selected from human pancreatic secretory trypsin inhibitor and minibody repertoires.

Given the extent of hepatitis C virus (HCV) infection as a worldwide health problem and the lack of effective treatment, the development of anti-HCV drugs is an important and pressing objective. Previous studies have indicated that proteolytic events mediated by the NS3 protease of HCV are fundamental to the generation of an active viral replication apparatus, as unequivocably demonstrated for flaviviruses. As a result, the NS3 protease has become a major target for discovering anti-HCV drugs. To gain further insight into the biochemical and biophysical properties of the NS3 enzyme binding pocket(s) and to generate biological tools for developing antiviral strategies, we decided to engineer macromolecular ligands of the NS3 protease domain. Phage-displayed repertoires of minibodies ("minimized" antibody-like proteins) and human pancreatic secretory trypsin inhibitor were sampled by using the recombinant NS3 protease domain as a ligate molecule. Two protease inhibitors were identified and characterized biochemically. These inhibitors show marked specificity for the viral protease and potency in the micromolar range but display different mechanisms of inhibition. The implications for prospective development of low-molecular-weight inhibitors of this enzyme are discussed.

Amino Acid Sequence↗
PubMed1997

Transforming growth factor beta 1, interleukin-8 and interleukin-1, in non-small-cell lung tumors.

A role in tumor progression has been proposed for transforming growth factor-beta 1 (TGF beta 1) and interleukin (IL)-8 as well as for IL-1, which itself induces the production of TGF beta 1 and IL-8 in many cell types. TGF beta 1 and IL-8 production and their regulation by IL-1 in five non-small-cell (NSC) lung tumor cell lines were evaluated. Moreover, their levels were evaluated in 29 NSC lung tumors. All cell lines constitutively produced TGF beta 1, and three produced IL-8. After IL-1 beta treatment, TGF beta 1 production was upregulated in two cell lines, whereas IL-8 production was markedly upregulated in two, induced in one, and unmodified in two. In tumors, the levels of TGF beta 1, IL-8, and IL-1 beta were higher than in normal counterparts (p < 0.001), and a positive correlation between IL-8 and IL-1 beta levels (p < 0.001) was found. TGF beta 1, IL-8, and IL-1 beta mRNA expression was examined in 12 tumors. TGF beta 1 mRNA was detected in all cases, IL-8 mRNA in 7, and IL-1 beta MRNA was undetectable. TGF beta 1, IL-8, and IL-1 beta immunoreactivity was then studied by immunohistochemistry. TGF beta 1 and IL-8 immunoreactivity was observed in neoplastic cells; IL-1 beta immunoreactivity was observed in mononuclear cells. In conclusion, in tumors IL-1 beta levels positively correlated with those of IL-8, and IL-1 beta as well as TGF beta 1 and IL-8 levels were significantly higher than in normal tissues.

Adenocarcinoma↗
PubMed1997

Economic evaluation of ACE inhibitor treatment of nephropathy in patients with insulin-dependent diabetes mellitus in Italy.

Diabetic nephropathy is one of the major complications of insulin-dependent diabetes mellitus (IDDM), with proteinuria being the main clinical manifestation of diabetic nephropathy. Most patients who develop overt proteinuria progress to end-stage renal disease (ESRD), usually within 5 to 7 years; ESRD necessitates dialysis or renal transplantation. Although a relationship between blood pressure reduction and delaying of ESRD has been assumed for a long time, only recently has a controlled randomised clinical trial shown that the treatment of diabetic nephropathy with an ACE inhibitor can significantly delay the loss of renal function and, therefore, ESRD. Consistent with the clinical trial on which this economic evaluation was based, the costs and consequences of 2 alternatives were considered: (i) patients subject to blood pressure control with only antihypertensive medication, but without an ACE inhibitor (placebo group) and (ii) patients given ACE inhibitor therapy (captopril group) with similar blood pressure control to the placebo group. This cost-effectiveness analysis was performed from the perspective of the Italian National Health Service [Servizio Sanitario Nazionale (SSN)]. Accordingly, only direct costs related to publicly funded healthcare services were included. The number of dialysis-years avoided (DYA) was the clinical end-point. A 10-year time horizon was considered for the economic evaluation. Captopril therapy was dominant, being at the same time more effective and less costly. The total cost for the captopril alternative during the 10-year period was 21,901,625 Italian lire (L; 1993 values) per patient, while total cost for the placebo alternative was L30,352,590 per patient. Compared with placebo, 20.01 DYA per 100 patients treated were estimated with captopril therapy during the trial period, equivalent to 2.4 months per patient. The robustness of this result was confirmed by sensitivity analysis: for both extremes, captopril remained dominant. This economic evaluation, requested by the Italian Ministry of Health, demonstrated savings in healthcare expenditure with the use of an ACE inhibitor in patients with proteinuria.

Adult↗
PubMed1997

Serum levels of tumour necrosis factor-alpha predict response to recombinant human erythropoietin in patients with myelodysplastic syndrome.

We measured pretreatment serum levels of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) in 25 patients with myelodysplastic syndrome receiving recombinant human erythropoietin (rhEPO) at dosages up to 300 U/kg thrice weekly for 12 weeks. Both TNF-alpha and IL-1 beta levels were measured using commercially available enzyme-linked immunoassays. A complete response (CR) was defined as a rise in untransfused haemoglobin concentrations of at least 2 g/dl or a 100% decrease in RBC transfusion requirements over the treatment period; a partial response (PR) was an increase in untransfused haemoglobin values of 1-2 g/dl or a decrease in RBC transfusion requirements equal to or greater than 50%; no response (NR) was defined as a response less than a PR. After 12 weeks of rhEPO treatment, four patients showed a CR, five patients a PR, and 16 patients NR. Serum levels of both TNF-alpha (80.5 %/- 64.8 vs 8.1 +/- 4.2 ng/l, P < 0.001) and IL-1 beta (60.4 +/- 49.9 vs 8.9 +/- 4.7 ng/l, P < 0.001) were higher in MDS patients than in a group of 28 normal controls. Responders (CR + PR) showed significantly lower serum levels of TNF-alpha than non-responders (21.6 +/- 26.2 vs 106.3 +/- 60.8 ng/l, P < 0.001), whereas IL-1 beta concentrations between those who benefited from therapy and unresponsive cases were not significantly different (39.8 +/- 48.9 vs 73.4 +/- 48.2 ng/l, P = 0.120). It is noteworthy that TNF-alpha levels were within the normal range in all responsive patients but one, whereas all non-responders presented elevated cytokine concentrations. No relationship was found between TNF-alpha or IL-1 beta values and haemoglobin levels, transfusion requirement, serum EPO or ferritin concentrations. We conclude that pre-treatment TNF-alpha levels might help to select those MDS patients who are most likely to benefit from rhEPO treatment.

Adult↗
PubMed1997

Response to recombinant human erythropoietin in patients with myelodysplastic syndromes.

Recombinant human erythropoietin (rhEPO) at pharmacological doses was used to improve anemia and reduce the transfusional requirements of 43 patients with myelodysplastic syndrome (MDS). rhEPO was given by s.c. injection three times per week for 12 weeks. The EPO dose was started at 150 IU/kg and was increased to 300 IU/kg if after 6 weeks there was no or suboptimal erythroid response. Responses were defined as being a complete response (CR), partial response (PR), or no response (NR). A CR was considered a rise in untransfused hemoglobin concentrations of at least 2 g/dl or a 100% decrease in RBC transfusion requirements over the treatment period. A PR was defined as an increase in untransfused hemoglobin values of 1-2 g/dl or a decrease in RBC transfusion requirements equal to or greater than 50%. NR was defined as responses less than a PR. Patients who responded to therapy were continued on rhEPO at the same dose for 6 additional months. An objective response (CR and PR) was observed in 7 of 42 (16.7%) assessable cases after 6 weeks of treatment at the dose of 150 IU/kg. Dose escalation (300 IU/kg) in nonresponders resulted in another six patients attaining a rise in hemoglobin concentrations. The final response rate was 13 of 41 (31.7%); 4 patients became transfusion independent. Therapy was tolerated well, with no relevant side effects. MDS progression was seen in one case. An elevated bone marrow erythroid infiltration (erythroid index) and detectable pretreatment circulating erythroid progenitors (burst-forming units-erythroid) were the best predictors of hemoglobin response when we controlled for other variables. These data suggest that rhEPO has a role in the treatment of certain patients with MDS, particularly in those with a high erythroid index and detectable circulating erythroid burst-forming units.

Adult↗
PubMed1995

Spontaneous and glucocorticoid-induced apoptosis in human mature T lymphocytes.

Glucocorticoid (GC)-induced apoptosis is a well-recognized physiologic regulator of murine T-cell number and function. We have analyzed its mechanisms in human mature T cells, which have been thought to be insensitive until recently. Peripheral blood T cells showed sensitivity to GC-induced apoptosis soon after the proliferative response to a mitogenic stimulation, and were also sensitive to spontaneous (ie, growth factor deprivation-dependent) apoptosis. CD8+ T cells were more sensitive to both forms than CD4+ T cells. Acquisition of sensitivity to GC-induced apoptosis was not associated with any change in number or affinity of GC receptors. Both spontaneous and GC-induced apoptosis were increased by the macromolecular synthesis inhibitors, cycloheximide (CHX) and puromycin. A positive correlation between the degree of protein synthesis inhibition and the extent of apoptosis was observed. Interleukin-2 (IL-2) IL-4, and IL-10 protected (IL-2 > IL-10 > IL-4) T cells from both forms of apoptosis in a dose-dependent manner. Our data suggest that spontaneous and GC-induced apoptosis regulate the human mature T-cell repertoire by acting early after the immune response and differentially affecting T-cell subsets.

Apoptosis↗
PubMed1995

Increased cerebrospinal fluid pyruvate levels in Alzheimer's disease.

Impaired energy metabolism is an early, predominant feature in Alzheimer's disease. In order to find out simple, reliable 'in vivo' markers for the clinical-biological typization of the disorder, we measured cerebrospinal fluid (CSF) glucose, lactate and pyruvate levels in patients suffering from dementia of Alzheimer type (DAT) and in healthy elderly controls. DAT group showed remarkably higher levels of pyruvate (P = 0.01), with no overlap with the values obtained in controls. CSF pyruvate levels were also significantly associated with the severity of dementia. Therefore, CSF pyruvate levels neatly separate DAT patients from controls, having also pathogenetic value.

Aged↗
PubMed1995

Possible involvement of L-glycero-phosphoryl-ethanolamine in the phospholipid methylation pathway.

It is usually accepted that GPEtn is only an intermediate in glycerophospholipid degradation. However, some years ago J. P. Infante published a review-hypothesis concerning the possible involvement of GPEtn and GPCho in the biosynthesis of acyl-specific glycerophospholipids in mammalian tissues. This paper reports the results obtained by incubating brain cortex slices in the presence of labeled GPEtn. GPEtn enters the cells and the radioactivity of the precursor is found in both PE and PC. When these results were compared with those obtained by incubating brain slices in the presence of 3H-Etn, a significantly higher amount of radioactivity was found in PC, mainly after short incubations in the presence of low concentrations of the precursors. The slopes of the methylated forms of PE further underline the above differences found by comparing the results obtained with the two precursors. The results presented in this paper suggest a possible role of GPEtn in phospholipid biosynthesis and methylation pathway of PE.

Analysis of Variance↗
PubMed1995

Role of cytokines in distribution and differentiation of dendritic cell/Langerhans' cell lineage in human primary carcinomas of the lung.

The possibility that production of some cytokines in the carcinoma microenvironment is associated with the presence and differentiation of cells belonging to the dendritic cell (DC)/Langerhans' cell (LC) lineage was investigated. Immunohistochemical examination showed the presence of intraepithelial LCs (CD1a- and S100-positive cells) in 6 of 10 squamous cell carcinomas and in 8 of 10 adenocarcinomas. Langerhans' cells were mainly located close to lymphoid aggregates. In situ hybridization performed in four cases (three LC positive and one LC negative) of squamous cell carcinoma and in five cases (four LC positive and one LC negative) of adenocarcinoma showed that some mononuclear cells in the interstitium displayed hybridization with granulocyte macrophage-colony stimulating factor (GM-CSF), tumor necrosis factor-alpha (TNF alpha), and interleukin 1-beta (IL1 beta) cDNA probes. Only in LC-positive carcinomas did epithelial cells close to lymphoid aggregates display small amounts of GM-CSF and TNF alpha mRNA expression. Immunohistochemical analysis performed in the 20 cases of lung carcinoma showed that epithelial cells in tumors with lymphoid aggregates and LCs were immunoreactive with antihuman GM-CSF monoclonal antibody. Specimens negative for GM-CSF contained very few LCs. Northern blot analysis was used to investigate GM-CSF, TNF alpha, IL1 alpha, and IL1 beta mRNA expression in six human lung carcinoma cell lines. A constitutive expression of TNF alpha mRNA was found in all of them, whereas only three showed a low constitutive expression of GM-CSF mRNA. In the latter three cell lines treatment with phytohemagglutinin (PHA)-stimulated peripheral blood lymphocyte (PBL) supernatant (PHA-SUP) upregulated GM-CSF mRNA expression and induced that of IL1 alpha mRNA. Carcinomatous epithelial cells producing small amounts of cytokines could promote the recruitment of cells of DC/LC lineage. Subcellular factors produced by reactive lymphocytes and/or macrophages may influence the production of GM-CSF and IL1 alpha by various epithelia. Up-regulation of this production could favor the arrival and differentiation of DCs and activate LC functions.

Adenocarcinoma↗
PubMed1995

Knowledge, beliefs, and prior screening behavior among blacks and whites reporting for prostate cancer screening.

OBJECTIVES: A survey to determine prostate cancer-related knowledge, beliefs, and prior screening behavior was administered to men participating in prostate cancer screening events at nine major sites in the southeast. Since prostate cancer disproportionately affects blacks, a primary focus of the analysis was to determine if differences in responses exist between racial groups. METHODS: A 20-question, multiple-choice survey to ascertain prostate cancer knowledge and beliefs, demographics, and health care access information was administered at nine major southeastern sites participating in Prostate Cancer Awareness screening events. Potential differences between the responses of blacks and whites were tested using the Cochran-Mantel-Haenszel test (P < 0.05), adjusting for differences among sites. RESULTS: Major findings of this study on 286 black and 1218 white men are as follows: (1) only 28% of black or white men report that their doctor ever discussed a test for prostate cancer with them; (2) blacks were less likely to have a regular doctor (P = 0.03) or ever to have had a digital rectal examination (P < 0.001) or prostate-specific antigen testing (P = 0.005); (3) blacks were less likely to report knowing someone with prostate cancer (P < 0.001) and were more apt to report their acquaintances experiencing post-treatment impotence than whites (P = 0.03); they were less likely to report that "a man with prostate cancer can lead a normal life" (P < 0.001) or that "men can have prostate cancer without symptoms" (P < 0.001); (4) a substantial number of all men did not know that race and/or heredity are risk factors; and (5) "peace of mind" was the leading reason why men (63% of whites and 50% of blacks) attended prostate cancer screening events. CONCLUSIONS: There are a number of similarities among black and white men regarding knowledge and beliefs related to prostate cancer. Important differences, however, in access to screening, perception of the disease and its treatment, and knowledge of risk factors exist between racial groups and represent significant barriers to early detection among African Americans.

Black or African American↗
PubMed1994

Platelet MAO-B activity as a marker of behavioural characteristics in dementia disorders.

Both low and high platelet MAO-B (pMAO-B) activity is considered an indicator of increased vulnerability in psychopathology. How the activity of this peripheral enzyme can be linked with the sophisticated functions of the central nervous system (CNS) is not clear; in man, evidence exists that the genetic mechanisms determining the size or capacity of the central serotonin system are common to platelet and brain MAO. In the present study pMAO-B activity was evaluated in demented patients suffering from early-onset Alzheimer's disease (AD), late-onset Alzheimer's disease (SDAT), vascular dementia (VD), and controls. In these dementia categories, the relationship between pMAO-B activity and clinical features, and between pMAO-B activity and cerebrospinal fluid (CSF) monoamine metabolites (3-methoxy-4-hydroxyphenyl-glycol, MHPG; 5-hydroxy-indoleacetic acid, 5-HIAA; homovanillic acid, HVA) was also investigated. pMAO-B activity was significantly higher in SDAT patients, compared to controls and AD. Age, as covariate, failed to show any significant effect, and no association was found between pMAO-B activity and CSF monoamine metabolites. The correlation analysis between pMAO-B and neuropsychological scores showed a highly significant positive relationship with GBS-emotional impairment (N = 40, r = 0.72, p < 0.01) in the SDAT group. This result suggests the importance of platelet MAO-B activity as biological marker also in old-age dementias, namely senile dementia of Alzheimer type, where the increased activity of this enzyme might constitute a marker for vulnerability toward behavioural disturbance, i.e., emotional deterioration.

Affective Symptoms↗
PubMed1992

Arachidonic and palmitic acid utilization in aged rat brain areas.

We have previously demonstrated that the arachidonic acid (20:4) incorporation into brain lipids differs according to the age of the animals used and the experimental conditions adopted. These differences led to a further investigation of arachidonic acid uptake in both aged and adult rat brains, its transformation into CoA derivatives, its incorporation into diacyl-glycerols and polar lipids, and finally its oxidation to CO2. These metabolic parameters were then compared with those obtained after using the saturated fatty acid palmitate (16:0). In both cases slices or mitochondria from different brain areas of 24-month-old and 4-month-old rats were examined. The results obtained indicate that the uptake of the fatty acids into cells is not modified by age. However, the successive metabolic transformations of the acids are altered to a considerable extent. In particular, in 24-month-old animals (compared with 4-month-old rats) there is a significant decrease of 20:4 in its incorporation into lipids as well as its oxidation to CO2, while arachidonoyl-CoA content increases by about 50%. This increased amount of CoA derivative, which has a potent detergent effect, may interfere with membrane structure and affect membrane physiological functions. Furthermore, because the free arachidonate pool is maintained in a dynamic equilibrium with its esterified forms, the final result may be a perturbation of this equilibrium.

Aging↗
PubMed1991

Choline incorporation into phospholipids in brain areas from spontaneously hypertensive rats: effect of oxiracetam treatment.

It has been demonstrated that spontaneously hypertensive rats (SHR) develop severe hypertension and cerebrovascular lesions on drinking 1% NaCl from weaning. These animals present a learning and memory impairment as well as impairment of both energy metabolism and membrane phospholipid turnover. We tested both choline uptake into the cells and incorporation into choline phosphoglyceride (CPG) by incubating slices from hippocampus and cortex. After 5 min of incubation, a noticeable decrease in free labelled choline content inside the cells as well as its incorporation into phospho-choline (PC) and CPG were found in the brain of SHR, as compared to Wistar-Kyoto (WK) rats. This may indicate that in the SHRs with cerebrovascular lesions there is a reduction in choline uptake which in turn causes a decline in CPG biosynthesis through de novo pathway. Oxiracetam treatment is able to restore the labeled choline content in the cells from SH rats, as well as the incorporation of choline into its derivatives PC and CPG, to the levels found in the WK or more. Tests performed in the presence of such a high affinity choline uptake as hemicholinium (HC) confirmed the capacity of oxiracetam to stimulate choline uptake into the cells even if the results obtained up to now are not sufficient to hypothesize a direct effect of oxiracetam on acetylcholine metabolism. In conclusion, from the results obtained it would seem reasonable to hypothesize that the effects of the drug above mentioned on the cholinergic system may be secondary to its effect on choline phosphoglycerides biosynthesis.

Animals↗
PubMed1987

Effect of aging on the rate of axonal transport of choline-phosphoglycerides.

The anterograde axonal transport of choline-phosphoglycerides was studied in sciatic nerve motoneurons of adult (3-month-old) and aged (24-month-old) rats. After the spinal cord injection of [2-3H]glycerol, choline-phosphoglycerides; the major phospholipid class was transported along the nerve. The axonal transport rate was determined by plotting the distance covered by the front of transported radioactivity as a function of the time employed. In aged animals the rate of the choline-phosphoglyceride anterograde axonal transport was about 68% lower than that of adults; furthermore, the rate slowed down along the nerve in the proximal-distal direction. This altered axonal transport mechanism might contribute to the degenerative processes observed in distal regions of peripheral nerve fibers of aged animals.

Aging↗
PubMed1987

Clonazepam/haloperidol combination therapy in schizophrenia: a double blind study.

Clonazepam (CLN), a benzodiazepine originally used as an anti-epileptic, was tested in schizophrenia in a double blind comparison in combination with haloperidol (HL). Twenty-four schizophrenic inpatients, diagnosed according to DSM III were treated with HL and CLN (Group 1) or HL and placebo (Group 2) for 4 weeks. The Brief Psychiatric Rating Scale (BPRS) and the Extrapyramidal Side Effect Scale (EPSE) were used for assessing psychopathological features and extrapyramidal side-effects before treatment and then weekly. No differences in specific schizophrenic symptoms were detected between the two groups, but in Group 1 an early significant BPRS amelioration was noticed compared to Group 2. Moreover, the excitement item improved significantly in Group 1 only, from the second week. Less severe EPSE scores were observed in Group 1 in comparison to Group 2. In conclusion the combination of CLN and HL seems to be preferred to HL alone in cases of psychotic excitement and in order to reduce the severity of extrapyramidal side-effects.

Adult↗
PubMed1986

Turnover of palmitic and arachidonic acids in the phospholipids from different brain areas of adult and aged rats.

[3H]Palmitic acid and [14C]arachidonic acid were injected together into the cerebral ventricle of 4-month and 24-month-old rats. At different time intervals from the injection, the distribution of these fatty acids in the lipids from different brain areas was examined. The fatty acids were rapidly incorporated into the lipids through different mechanisms. The time-specific activity relationship indicate that the utilization of the fatty acid differs according to the different areas and aging decreases the utilization of both the fatty acids. The decline of arachidonic acid incorporation into phospholipids is particularly evident, indicating that aging affects mainly the utilization of polyunsaturated fatty acids.

Aging↗