Biomedical subjects

M Falcone

Publications and source records attributed to M Falcone.

At least 37 records · Page 2Linked to original sources

PubMed1997

[Feasibility and safety of dobutamine/atropine echocardiography following acute myocardial infarct].

BACKGROUND: Due to the increased utilization of this test for the evaluation of chest pain and for prognostic stratification in patients with a recent myocardial infarction, the results of 235 consecutive tests have been analyzed to evaluate the incidence and clinical significance of side effects induced by dobutamine. A potential limitation to the clinical utilization of dobutamine stress echocardiography is the higher incidence of side effects comparison with to other non invasive tests for the diagnosis of coronary artery disease reported by some authors. METHODS: Dobutamine/atropine stress echocardiography was performed in 256 patients affected by acute myocardial infarction. Dobutamine was infused starting with the dose of 5 micrograms/kg/min over 3 minutes with incremental steps of 10-20-30-40 micrograms/kg/min over 3 minutes and atropine, in cases of poor chronotropic response, under 2D-echocardiographic and 12-lead electrocardiographic monitoring. RESULTS: The test was interrupted only in 4 cases for atrial fibrillation (2 patients) and symptomatic hypotension. Patients were divided according to the absence (G1) or presence (G2) of cardiac arrhythmias during the test. Patients of G2 differred from patients of G1 only in respect of the maximal dose of dobutamine infused and the incidence of a wall motion abnormality in the basal echocardiogram. CONCLUSIONS: Dobutamine/atropine echo stress test may be considered a safe test for the evaluation of the presence and severity of coronary artery disease in patients with a previous or recent myocardial infarction.

Acute Disease↗

PubMed1996

The immune response to mycobacterial 70-kDa heat shock proteins frequently involves autoreactive T cells and is quantitatively disregulated in multiple sclerosis.

Heat shock proteins (HSP) are the most conserved molecules known to date that may also function as immune targets during infection. Hence, theoretically there is a high chance of cross-reactive responses to epitopes shared by host and microbe HSP. If not properly regulated, these responses may contribute to the pathogenesis of autoimmune disease. To determine if immune responses to HSP could contribute to the pathogenesis of multiple sclerosis, we raised T lymphocyte lines specific for the purified protein derivative of Mycobacterium tuberculosis (PPD) from patients with multiple sclerosis, patients with tuberculosis and from healthy individuals. These lines were then screened for their proliferative response to a M. tuberculosis 70-kDa heat shock protein (M.tb.HSP70). The relative frequency of the recognition of highly conserved sequences of M.tb.HSP70 compared to variable ones was also assessed by mapping experiments on those PPD specific T lymphocyte lines which also recognized the mycobacterial 70-kDa heat shock protein. In patients with multiple sclerosis, we observed a significantly higher estimated frequency of PPD-specific T lines responding to M.tb.HSP70 compared to healthy individuals and patients with tuberculosis. Furthermore, mapping experiments using recombinant proteins representing mycobacterial and human HSP70 sequences and a panel of synthetic peptides encompassing the whole sequence of Mycobacterium leprae HSP70, showed that the response to conserved epitopes of HSP70 is a frequent event in each of the three conditions studied, often leading to the cross-recognition of microbial and human sequences. These findings implicate the 70-kDa heat shock proteins as potential autoantigens in multiple sclerosis.

Adult↗

PubMed1996

[Human recombinant erythropoietin in the treatment of anemia in obstetric-gynecologic patients. Evaluation of such treatment as an alternative to blood transfusion].

The authors introduce the subject with physiological comments regarding the ability of r-HuEP to stimulate erythropoietic bone marrow, underlining the need for other molecules to backup the therapy (vitamin B12, folic acid and iron). Subsequently, and in the light of this introduction, they outline the indications for r-HuEPO treatment in specialist fields and the relative contraindications. They then report the results obtained in a group of 24 patients with the relevant indications receiving subcutaneous treatment on alterate days with r-HuEPO in fials of 4000 IU/ml. Basal hemoglobin levels were 6-8 g and treatment was continued until levels of around 10-11 g were reached; tolerance was good in both gynecological and obstetric patients.

Adult↗

PubMed1995

Three different thyroid hormone receptor isoforms are detected in a pure culture of ovine oligodendrocytes.

Thyroid hormones are important for the normal development of the central nervous system. In humans, the period around the end of the intrauterine life and the first few months of neonatal life is critically dependent on the presence of normal amounts of thyroid hormone. There are significant events occurring during this time; myelination is one. Myelin is synthesized by oligodendrocytes. A panel of site-specific polyclonal antibodies against alpha-1 thyroid hormone receptor (TR), alpha-2 variant TR, and beta-1 TR isoforms has been employed to investigate the presence of TR isoforms in a pure culture of ovine oligodendrocytes by the avidin-biotin peroxidase immunocytochemical method. Strong nuclear staining was obtained with all the anti-TR antibodies; no reaction products were detected in the cytoplasm or cellular processes. By contrast, an anti-myelin basic protein antibody gave strong cytoplasmic and process staining; no nuclear staining was seen. These latter results served to 1) confirm that the cells under study are oligodendrocytes; and 2) prove that the nuclear staining with anti-TR antibodies is specific. Preimmune sera were totally negative. Scatchard analysis of [125I] T3 binding by isolated oligodendrocyte nuclei demonstrated the existence of high-affinity--low-capacity T3 binding sites with a Ka of approximately 6 x 10(-9) M and a maximal binding capacity of approximately 20 fmol/100 micrograms of DNA. Our results demonstrate that differentiated oligodendrocytes express alpha-1 and alpha-2 variant and beta-1 isoforms of TR at the protein level and support the notion of a direct impact of thyroid hormones on oligodendrocytes in their regulation of myelin synthesis.

Animals↗

PubMed1995

[Validity of instrumental tests, individual and combined, in the rapid diagnosis of extra-uterine pregnancy].

Extrauterine pregnancy is an increasingly frequent pathology. It is also responsible for a high percentage of maternal deaths. This figure is closely correlated to the rapidity of diagnosis. This retrospective study analyses cases of extrauterine pregnancy observed over a 10-year period and aims to evaluate the value, in terms of an early or rapid diagnosis, of various instrumental tests, the used either alone or in association.

Female↗

PubMed1995

[Measurement of anti-HCV IgM antibodies with an experimental kit].

The aim of this study was to search for specific anti-HCV IgM antibodies. The author proposes an immunoenzymatic method used to assay IgM specific antibody utilising routinely available techniques. The study was performed over a two-month period in out-patients referred by general practitioners for anti-UCV antibody assay to the Immunohematology and blood transfusion Service in Foggia. A total of 206 subjects were examined. Anti-HCV IgM antibody assay is made possible by a two-step procedure: the absorption of IgM-type rheumatoid factor and the use of anti-IgM antibodies conjugated with alkaline phosphatase. After preincubation of the serum diluted in absorption medium, the sample is set on a sensitised plate and incubated overnight. After washing and the addition of anti-HCV IgM antibodies conjugates to alkaline phosphatase, the plate is again incubated for 90 min at 37 degrees C. This is followed by washing and the deposition of the substrate, before a further 30-min incubation at 37 degrees C. A blocking solution (NaOH) is then added and the plate is read at 405 nm. Data obtained only indicated the positivity or negativity to the routine test or to the experimental test: for organisational reasons it was not possible to perform a follow-up of positive subjects or observe the correlation with other disease markers. Out of a total of 209 subjects examined, 8 (3.8835%) were positive to both IgG anti-HCV IgM, whereas 10 (4.8544%) were positive to anti-HCV IgM alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Biological Assay↗

PubMed1995

Gamma delta T cell receptor analysis supports a role for HSP 70 selection of lymphocytes in multiple sclerosis lesions.

BACKGROUND: Interactions between gamma delta T cells and heat shock proteins (HSP) have been proposed as contributing factors in a number of diseases of possible autoimmune etiology but definitive evidence to support this hypothesis has been lacking. In multiple sclerosis (MS), a chronic inflammatory neurologic disease, HSP and gamma delta T cells are known to colocalize in brain lesions. Analysis of T cell receptor (TCR) gene usage in these lesions has detected evidence of clonality within both the V delta 2-J delta 1 and V delta 2-J delta 3 populations of gamma delta T cells. In our own studies, using direct sequence analysis, a dominant V delta 2-J delta 3 TCR sequence was found in 9 MS brain samples, suggesting a response to a common antigen. In this report, we have examined gamma delta T cell receptor gene usage in MS peripheral blood T cell lines selected for reactivity to HSP 70. MATERIALS AND METHODS: TCR rearrangement patterns for V delta 2-J delta 1 and V delta 2-J delta 3 were studied using the polymerase chain reaction (PCR) and a direct sequencing technique in populations of peripheral blood mononuclear cells (PBMC) cultured with Mycobacterium tuberculosis (M. tuberculosis) purified protein derivative (PPD) and then selected for reactivity to a 70-kD heat shock protein (HSP70). Cells were obtained from health donors, patients with MS, and patients with tuberculosis (TB). PCR products were subjected to direct sequence analysis to look for evidence for clonality within these T cell lines and to define the sequence of the V-D-J (CDR3) region of the TCR. RESULTS: In freshly isolated PBMC, both V delta 2-J delta 1 and V delta 2-J delta 3 gene rearrangement patterns were detected, whereas in HSP70+ T cell lines the predominant delta chain rearrangement pattern was V delta 2-J delta 3. Direct sequence analyses indicated that in cells reactive with HSP70 the V delta 2-J delta 3 sequences were usually oligoclonal and used D delta 3 exclusively. In four of four MS and two of three TB patients, the oligoclonal sequences in the HSP70+ T cell lines were identical to one another and to a dominant sequence previously detected in MS brain lesions. In two of three HSP70+ T cell lines from healthy controls, the oligoclonal sequences differed from those found in both groups of patients but were identical to one another except for a small region of heterogeneity in the second N region. In contrast, in freshly isolated PBMC or in PPD+HSP70- T cell lines, the V delta 2-J delta 3 gene rearrangement patterns were usually polyclonal and dominant sequences were rarely identified. CONCLUSIONS: These results support the conclusion that a subpopulation of gamma delta T cells in MS lesions are responding to HSP 70 and that non-CNS-specific antigens contribute to the pathogenesis of MS.

Amino Acid Sequence↗

PubMed1994

Evaluation of the ontogeny of thyroid hormone receptor isotypes in rat brain and liver using an immunohistochemical technique.

We performed an immunohistochemical study on rat brain and liver during fetal and neonatal life using rabbit antipeptide polyclonal antibodies able to recognize each thyroid hormone receptor (TR) isoform. The expression of TR alpha-1, alpha-2 and beta-1 proteins from 14 days of gestation to 21 days after birth was evaluated. Frozen tissues from 14 (F14), 17 (F17) and 21 (F21)-day-old fetuses and from 5 (N5), 16 (N16) and 21 (N21)-day old newborn rats were stained with anti-TR antibodies using an avidin-biotin-peroxidase system. The antipeptide antibodies utilized in the present study were characterized previously: alpha-144 antibody recognizes both TR alpha-1 and alpha-2; alpha-2-431 antibody is specific for TR variant alpha-2, and beta-62 antibody specifically reacts with the TR beta-1 isoform. The expression of TR alpha-1 was deduced by comparing the staining obtained with alpha-144 and alpha-2-431 antibodies. We demonstrated that each TR isoform is expressed in rat brain from 14 days of gestation and that the alpha isoform was predominant in the early stage. The three TR isoforms were expressed in both neural cell nuclei and in glial cell nuclei. As far as the liver is concerned, at F14 the expression of TR isoforms was weaker in hepatocytes when, on the contrary, TR alpha was clearly detected in hematopoietic cells. The expression of TRs in hepatocytes becomes evident later. The data that we obtained, although not quantitative, emphasize the presence of each TR isoform in brain and liver from 14 days of fetal rat life.

Animals↗

PubMed1993

Predominant and stable T cell responses to regions of myelin basic protein can be detected in individual patients with multiple sclerosis.

T lymphocytes from patients with multiple sclerosis (MS) recognize multiple myelin basic protein (MBP) epitopes. This situation complicates the design of specific immunotherapies. We investigated to which extent the T cell response to MBP is heterogeneous in single subjects in terms of preferentially recognized regions of the molecule, major histocompatibility complex (MHC) restriction, and stability over time. From each of nine patients with MS, a minimum of six MBP-specific T lymphocyte lines (TLL) were assayed for the proliferative response to a panel of overlapping peptides, encompassing the whole MBP. Predominant T cell recognitions of distinct MBP regions were present in three patients, all HLA-DR2+, independently of the clinical features of their disease. T cell reactivity was preferentially directed to residues 16-38 in one patient. In this case the response was also stable over time, during different phases of the disease. Predominant reactivity to residues 86-99 was detected in the two other DR2+ patients. In each of the patients with other HLA-DR haplotypes (DR2-), as well as in three DR2+ non-MS donors, the T cell response to MBP appeared to be considerably more heterogeneous. The HLA restriction element varied among TLL recognizing the same MBP region, even when raised from the same individual. The genomic HLA typing, performed on the DRB1 and DRB5 genes in the DR2+ subjects, showed no obvious correspondence between preferential responses to regions of MBP and HLA-DR2 subtypes. In this context, a simple, new method for the genomic typing of the HLA-DRB1 gene in individuals with the HLA-DR2 serological specificity is also described. We conclude that predominant and stable T cell responses to a single MBP region can be detected in some patients with MS. In these individuals, the MHC restriction of the T cell recognition of predominant regions appears to be variable. Polymorphisms of the HLA-DR2 gene products alone do not account for the selection of the dominant MBP T cell epitope.

Adolescent↗

PubMed1993

Target epitopes of myelin basic protein specific T cell lines in multiple sclerosis.

A highly efficient new method for the generation of antigen specific T cell lines (TCL) is now available. By this method we established 134 myelin basic protein (MBP) TCL from the peripheral blood of 9 patients with definite multiple sclerosis (n = 69) and 8 healthy donors (n = 65). The yield of MBP reactive TCL in the two groups was comparable. So far 22 MBP specific TCL from 7 patients and 24 from 7 healthy individuals have been tested for their proliferative response to a panel of four synthetic peptides representing MBP residues 7-26, 80-99, 139-153 and 148-162. Although the peptide sequences did not encompass the whole MBP, the pattern of reactivity to these peptides in patients and controls seems to be similar. Further, when multiple TCL from the same donor were analysed, no dominant recognition emerged.

Adult↗

PubMed1993

Peptides from multiple regions of the lectin domain of P-selectin inhibiting neutrophil adhesion.

The selectins are a family of three structurally related glycoproteins that are integral components of leukocyte adhesion to the vascular endothelium. Their involvement in the recruitment and extravasation of neutrophils is critical in mounting an inflammatory reaction. The carbohydrate nature of the selectin ligands suggests that the binding regions of the selectins are contained within the lectin-like domains of the selectins. The synthesis and evaluation for inhibition of selectin binding of overlapping peptides of the lectin and adjacent EGF-like domains of P-selectin have been used to identify small peptides that completely inhibit P-selectin-dependent neutrophil adhesion. These peptides span a region of more than 100 amino acids and may define the carbohydrate recognition domain of P-selectin.

Amino Acid Sequence↗

PubMed1992

Antipeptide polyclonal antibodies specifically recognize each human thyroid hormone receptor isoform.

We characterized four antipeptide polyclonal antibodies (abs) able to specifically recognize each thyroid hormone receptor (TR) isoform. The abs immunoprecipitated both the in vitro synthesized receptor and the receptor expressed in E. coli and their specificity was confirmed by competition studies and immunohistochemistry. Ab activity measured by enzyme-linked immunosorbent assay decreased after preabsorption of each ab with the immunizing peptide or the specific receptor protein expressed in E. coli. No specific activity was detectable in enzyme-linked immunosorbent assay, no nuclear staining was observed after affinity column immunoabsorption, and the specific bands obtained in Western blot analysis disappeared after preabsorption with the specific TR isoform expressed in E. coli. By immunohistochemical studies we detected coordinate expression of each receptor isoform in most tissues examined. However, in heart and muscle, the beta-isoform is expressed at a very low level compared to the alpha-isoform in spite of the significant TR beta mRNA levels previously demonstrated by Northern blot analysis. We also demonstrated a different pattern of distribution of alpha- and beta-isoforms in rat testis. In this tissue the TR alpha is significantly expressed in spermatogonia nuclei, but in spermatids the beta-isoform is predominant, and only the TR beta is detectable in mature spermatozoa.

Animals↗

PubMed1992

Site-specific anti-c-erb A antibodies recognizing native thyroid hormone receptors: their use to detect the expression and localization of alpha and beta c-erb A proteins in rat liver.

The cell-specific expression and tissue distribution of c-erbA proteins alpha and beta is still unknown. To address this problem, we prepared anti-peptide antibodies directed against epitopes of human (h) c-erbA, specific for the alpha or beta form of thyroid hormone receptors. The cDNAs coding for h c-erbA beta 1, alpha 1 and alpha 2 were transcribed and the mRNAs were translated in vitro in the presence of 35S-methionine, and then their reactivity with the antisera was evaluated. The antiserum anti-beta 62-81 immunoprecipitated only the beta 1 receptor. The antiserum anti-alpha 144-162 determined precipitation of both alpha 1 and alpha 2 proteins but not of the beta 1 receptor. Anti-alpha 2 431-451 produced a selective precipitation of alpha 2, and had no effect on alpha 1 or beta 1 receptor. In order to study the interaction of the antibodies with native T3 receptor we evaluated the binding of antibodies to rat liver T3 receptors by Sephacryl S300 chromatography: both antisera anti-beta 62-81 and anti-alpha 144-162 caused a partial shift of the labeled T3-receptor complex to a higher molecular form, while the antibody directed against c-erbA alpha 2 did not produce any significant shift. The anti-peptide antibodies were then immunopurified by affinity chromatography and used to immunolocalize the different forms of c-erb A proteins in adult and fetal rat liver, by a sensitive immunohistochemical technique. All 3 antibodies stained mainly the nuclei of the majority of adult liver cells. No staining was detectable when the original antiserum was deprived of anti-peptide antibodies by running through the affinity columns or when the antibodies were pre-absorbed with the homologous peptide. No significant staining was present in the liver from rat fetus.

Animals↗

PubMed1991

Activity of L-carnitine and L-acetylcarnitine on cholinoceptive neocortical neurons of the rat in vivo.

Carnitine and acetylcarnitine have been demonstrated to be present in the CNS and to be involved in cholinergic mechanisms, even if their exact role in neurotransmission is still unknown. This microiontophoretic study was carried out on single cholinoceptive neurons of the somatosensory cortex in the rat in order to analyze the effects of L- and D-carnitine and L-acetylcarnitine on the spontaneous firing and the neuronal responses to some putative transmitters. L-carnitine and L-acetylcarnitine increased the spontaneous discharge rate, while D-carnitine was found to be ineffective. L-acetylcarnitine clearly potentiated the cholinergic excitatory responses. On the contrary, L-carnitine was found to reduce cholinergic responses in a great percentage of units and to inhibit L-acetylcarnitine-induced excitatory responses. Atropine blocked the increase in firing rate induced by L-carnitine and L-acetylcarnitine, thus suggesting for both of them a muscarinic activity. No interactions were observed between carnitines and GABA and glutamate. These results show that carnitine and acetylcarnitine are stereospecific neuroactive compounds with a cholinomimetic activity. They may play a role in a modulatory system for the cholinoceptive cortical neuron.

Acetylcarnitine↗

PubMed1990

Lack of nocturnal serum thyrotropin surge after surgery.

The effects of surgery on TSH secretion, with particular regard to the nocturnal TSH surge, were evaluated in 10 consecutive patients followed for 6 days after surgery. Surgical trauma was associated in all patients with significant decreases in serum total and free T3 and a significant increase in serum rT3 levels, with no variations in serum total and free T4 concentrations. A marked increase in serum cortisol levels was observed, with higher values at night than in the morning. Serum cortisol levels and circadian rhythm normalized on the fifth day. Serum TSH values in the morning significantly decreased on the first day after surgery and returned to normal on the second day. Serum TSH values at night (2400-0200 h) were higher than in the morning preoperatively, but the nocturnal surge was abolished from days 1-5 after surgery and was restored only on the sixth day. Thus, surgery was associated with a prolonged loss of the nocturnal serum TSH surge. This effect on TSH secretion was more marked than predictable on the basis of serum TSH measurements in the morning alone. An inverse relationship was found between serum cortisol and serum TSH values at night, suggesting that the excessive endogenous cortisol secretion might play a role in the derangement of TSH secretion.

Adult↗

PubMed1990

Nocturnal serum thyrotropin (TSH) surge and the TSH response to TSH-releasing hormone: dissociated behavior in untreated depressives.

TSH secretion, with particular regard to the nocturnal surge of the hormone, was evaluated in 15 women (age range, 35-66 yr; mean, 50 yr) with untreated major endogenous depression and 15 healthy women (age range, 32-67 yr; mean, 53 yr) using an ultrasensitive assay. Mean morning (0830 h) TSH values did not differ in the 2 groups (1.3 +/- 02 mU/L in depressives and 1.4 +/- 0.1 mU/L in controls), whereas mean nighttime (2400-0200 h) values were significantly reduced in depressives (1.5 +/- 0.3 vs. 3.1 +/- 0.3 mU/L; P less than 0.0005). At variance with the control group, morning and nighttime TSH values did not differ in the depressives. The nocturnal serum TSH surge was abolished in 14 of 15 depressed patients. The mean peak TSH value after TRH was slightly yet significantly lower in the depressives. Patients with subnormal (less than 0.4 mU/L) TSH values in the morning had a serum TSH increase after TRH less than 2 mU/L in 5 of 6 cases and a lack of the nocturnal TSH surge in 6 of 6. Among the 9 patients with normal TSH values in the morning, the nocturnal serum TSH surge was lost in 8 of 9, whereas the response to TRH was normal in all. The depressives, at variance with other reports, showed significantly lower values of total and free thyroid hormones. Mean serum sex hormone-binding globulin (SHBG) and ferritin were also significantly reduced. In conclusion, major endogenous depression is associated with a major impairment of TSH secretion, which baseline TSH measurements in the morning and the evaluation of the TSH response to TRH may not reveal. In this regard, the loss of the nocturnal serum TSH rise would appear to be a more sensitive indicator of hypothalamus-pituitary-thyroid axis alterations in depressives than the TRH test, which is commonly used in the evaluation of these patients. The lack of the nocturnal TSH surge may be responsible for the reduced thyroid hormone secretion and supports the case for some degree of central hypothyroidism in endogenous depression.

Adult↗

PubMed1989

[Tumor markers in the early diagnosis of thyroid neoplasms].

Radioimmunological techniques were used to assay tumour markers in order to identify neoplasms in patients with thyroid nodules at the earliest possible stage. In the 7 patients with differentiated thyroid tumours, the marker findings were within normal limits. On the basis of these results it is concluded that at the present time these markers are of no value for the early diagnosis of thyroid tumours.

Adolescent↗

PubMed1988

Thyroxine uptake by human hepatoma cells from serum of patients submitted to long-term thyroxine suppressive therapy.

The significance of thyroxine (T4) uptake from serum in the assessment of thyroid status was evaluated, using human hepatoma (Hep G2) cells, in 30 euthyroid subjects, 6 hypothyroid and 19 hyperthyroid patients, and in 23 athyreotic cancer patients under T4 suppressive therapy. Cellular thyroxine (CT4) was determined according to Sarne and Refetoff, J. Clin. Endocrinol. Metab. 61: 1046, 1985. CT4 averaged 9.9 +/- 2.8 pg/well (mean +/- SD, range 5.7-15.3) in euthyroid subjects, 1.5 +/- 1.0 pg/well (range 0.05-4.2) in hypothyroid patients, 40.5 +/- 18.8 pg/well (range 18.3 +/- 104.7) in hyperthyroid patients, and 23.7 +/- 7.2 pg/well (range 14.2-40.2) in T4-treated patients. In eu-, hypo- and hyperthyroid patients, a significant correlation was observed between CT4 and free T4 index (FT4I), free T4 (FT4) or Sex Hormone Binding Globulin (SHBG) values. In T4-treated patients, CT4 values were correlated with FT4I values, but not with FT4 or SHBG levels. All T4-treated patients with elevated SHBG levels had elevated FT4, FT4I and CT4 values. In contrast, of the 16 T4-treated subjects with normal serum SHBG concentrations, all but one had normal FT3, 3 (19%) had elevated FT4, 10 (62%) elevated FT4I and 13 (81%) elevated CT4, but all (100%) had undetectable TSH levels. Thus, considering serum SHBG concentrations as a parameter of hepatic tissue response to thyroid hormone, CT4 values, at least in T4-treated patients, do not accurately reflect the liver responsiveness to thyroid hormone action.

Carcinoma, Hepatocellular↗