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Biomedical subjects

A Caruso

Publications and source records attributed to A Caruso.

At least 19 recordsLinked to original sources
PubMed2001

Adult human heart microvascular endothelial cells are permissive for non-lytic infection by human cytomegalovirus.

OBJECTIVE: Human cytomegalovirus (CMV) infection has been linked to chronic heart disease. The mechanism of CMV dissemination to the heart remains unknown. CMV antigens and nucleic acid sequences have been detected in endothelial cells (ECs) in vivo, and ECs are fully permissive hosts to CMV replication in vitro. This report examines the characteristics of CMV replication in primary cultures of human heart microvascular ECs (HHMECs). METHODS: Capillary ECs were isolated from heart tissue biopsies of six patients at the time of heart surgery. HHMECs were infected with CMV and viral antigens were detected by immunofluorescence assay using monoclonal antibodies as specific reagents. Cytokine and chemokine release in the supernatant of sham- and CMV-infected cells was quantitated by ELISA. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to analyse expression of mRNA for adhesion molecules. RESULTS: CMV was found to productively infect HHMECs without cytolytic effects. Infected cultures released high levels of pro-inflammatory chemokines and enhanced their adhesion molecule expression. CONCLUSIONS: Our data provide new insights into the mechanism of CMV dissemination to the heart, signalling the need for further investigation of the pathogenetic role of this virus in cardiac disorders.

Adult↗
PubMed2001

CD11b expression identifies CD8+CD28+ T lymphocytes with phenotype and function of both naive/memory and effector cells.

A previously unreported CD8(+)CD28(+)CD11b(+) T cell subset occurs in healthy individuals and expands in patients suffering from primary viral infections. In functional terms, these cells share the features of naive/memory CD8(+)CD28(+)CD11b(-) and terminally differentiated effector CD8(+)CD28(-)CD11b(+) subpopulations. Like CD28(-) cells, CD28(+)CD11b(+) lymphocytes have the ability to produce IFN-gamma, to express perforin granules in vivo, and to exert a potent cytolytic activity. Moreover, these cells can respond to chemotactic stimuli and can efficiently cross the endothelial barrier. In contrast, like their CD11b(-) counterpart, they still produce IL-2 and retain the ability to proliferate following mitogenic stimuli. The same CD28(+)CD11b(+) subpopulation detected in vivo could be generated by culturing naive CD28(+)CD11b(-) cells in the presence of mitogenic stimuli following the acquisition of a CD45RO(+) memory phenotype. Considering both phenotypic and functional properties, we argue that this subset may therefore constitute an intermediate phenotype in the process of CD8(+) T cell differentiation and that the CD11b marker expression can distinguish between memory- and effector-type T cells in the human CD8(+)CD28(+) T cell subset.

CD28 Antigens↗
PubMed2001

Phenylamides of 1-phenyl (or methyl)-5-benzamidopyrazole-4-carboxylic acid as vratizolin analogs with analgesic and antiinflammatory activities.

A number of phenylamides of 5-benzamidopyrazole-4-carboxylic acid were prepared in 50-80% yields from 1-phenyl (or methyl)-6-phenylpyrazolo[3,4-d]1,3-oxazin-4(1H)-ones and aniline derivatives. All the compounds were tested for their analgesic and antiinflammatory activities, as well as for their ulcerogenic potential and acute toxicity. Some derivatives, when compared to phenylbutazone, proved more active in the tests for analgesic and antiexudative activities, but less active in the carrageenin paw oedema test. The compounds proved to posses marginal or no ulcerogenic effect, as well as low systemic toxicity.

Analgesics↗
PubMed2001

Identification of Fas-L-expressing apoptotic T lymphocytes in normal human peripheral blood : in vivo suicide.

Fas-L molecules expressed by in vitro stimulated T cells may be critically involved in suicidal activation-induced cell death (AICD) of such cells through engagement of their Fas receptors. A similar suicide of T cells was postulated to occur even in vivo, to eliminate dangerous activated lymphocytes; however, the demonstration of suicidal AICD of T cells in healthy humans in vivo is still lacking. We therefore investigated the possible occurrence of Fas-L-linked suicidal apoptosis of T cells in normal human peripheral blood. For this purpose, we took advantage of immunoelectron microscopy, which allows simultaneous visualization of the morphological apoptotic cellular changes together with surface expression of Fas-L molecules. Very few T lymphocytes were observed showing the ultrastructural features of apoptotic lymphocytes; these occasional apoptotic T cells, together with the majority of the normal T cell population, expressed the Fas molecule on the plasma membrane, as expected. Interestingly, the apoptotic cells were also Fas-L-positive, whereas normal T cells were Fas-L-negative. Such Fas-L-associated T cell suicide operating in vivo in healthy individuals is presumably able to suppress immune responses and prevent autoreactivity, thus maintaining the homeostasis of human blood.

Apoptosis↗
PubMed2001

Polycyclic aromatic hydrocarbons (PaHs) in subcutaneous biopsies of Mediterranean cetaceans.

The aim of the present study was to measure polycyclic aromatic hydrocarbon (PAH) levels in free-ranging Mediterranean cetaceans as they are likely to cause chemical stress in the organisms of this basin. Blubber samples were collected from live specimens of fin whales (Balaenoptera physalus) and striped dolphins (Stenella coeruleoalba) by means of biopsies, a non-destructive biological method. Fin whales were sampled in the Ligurian Sea, whereas striped dolphins were collected in the Ligurian and the Ionian Seas. A fingerprint of 14 PAHs was obtained for both species. In whales, the median value of total PAHs was 1970 ppb fresh weight (f.w.) while median carcinogenic PAH values were 89.80 ppb f.w.; in dolphins, the median values of total and carcinogenic PAHs were 29,500 and 676.00 ppb f.w., respectively. The different PAH values between the two species can be attributed to the different positions they take in the Mediterranean food web. The sampling period significantly influenced PAH concentrations of fin whales.

Adipose Tissue↗
PubMed2001

Role of soy diet and L-arginine in cyclosporin-A-induced osteopenia in rats.

Our previous studies show that chronic administration of L-arginine decreases cyclosporin-A-induced bone loss. The present study was designed to investigate whether a soy diet could prevent cyclosporin A-induced osteopenia and eventually improve the protective effect of L-arginine. Rats on soy diet were treated with cyclosporin-A, L-arginine, cyclosporin-A + L-arginine or saline. Control groups received a normal diet and the same pharmacological treatment. Our results show that a soy diet prevents osteopenia only in the spinal cord (+30%) and confirm the protective effect of L-arginine in cyclosporin-A-induced osteopenia in whole body, pelvis and spine of rats on a normal diet (+31%, +55%, +55%, respectively). Moreover these data show that the osteoprotective effect of L-arginine in the whole body, pelvis and spine improves in the case of soy diet (+60%, +72%, +89%, respectively). The results suggest that a soy diet exerts a positive effect in cyclosporin-A-induced osteopenia only in sites with high turn-over and improves the osteoprotective effect of L-arginine.

Animals↗
PubMed2001

Human vasculogenesis ex vivo: embryonal aorta as a tool for isolation of endothelial cell progenitors.

SUMMARY: Vasculogenesis, the de novo formation of new blood vessels from undifferentiated precursor cells or angioblasts, has been studied with experimental in vivo and ex vivo animal models, but its mechanism is poorly understood, particularly in humans. We used the aortic ring assay to investigate the angioforming capacity of aortic explants from 11- to 12-week-old human embryos. After being embedded in collagen gels, the aorta rings produced branching capillary-like structures formed by mesenchymal spindle cells that lined a capillary-like lumen and expressed markers of endothelial differentiation (CD31, CD34, von Willebrand factor [vWF], and fms-like tyrosine kinase-1 [Flk-1]/vascular endothelial growth factor receptor 2 [VEGFR2]). The cell linings of these structures showed ultrastructural evidence of endothelial differentiation. The neovascular proliferation occurred primarily in the outer aspects of aortic rings, thus suggesting that the new vessels mainly arose from immature endothelial precursor cells localized in the outer layer of the aortic stroma, ie, a process of vasculogenesis rather than angiogenesis. The undifferentiated mesenchymal cells (CD34+/CD31-), isolated and cultured on collagen-fibronectin, differentiated into endothelial cells expressing CD31 and vWF. Furthermore, the CD34+/CD31+ cells were capable of forming a network of capillary-like structures when cultured on Matrigel. This is the first reported study showing the ex vivo formation of human microvessels by vasculogenesis. Our findings indicate that the human embryonic aorta is a rich source of CD34+/CD31- endothelial progenitor cells (angioblasts), and this information may prove valuable in studies of vascular regeneration and tissue bioengineering.

Antigens, CD34↗
PubMed2001

Increased expression of NR2A subunit does not alter NMDA-evoked responses in cultured fetal trisomy 16 mouse hippocampal neurons.

The trisomy 16 (Ts16) mouse is an animal model for human trisomy 21 (Down's syndrome). The gene encoding the NR2A subunit of the NMDA receptor has been localized to mouse chromosome 16. In the present study, western blot analysis revealed a 2.5-fold increase of NR2A expression in cultured Ts16 embryonic hippocampal neurons. However, this increase did not affect the properties of NMDA-evoked currents in response to various modulators. The sensitivity of NMDA receptors to transient applications of NMDA, spermine, and Zn(2+) was investigated in murine Ts16 and control diploid cultured embryonic hippocampal neurons. Peak and steady-state currents evoked by NMDA were potentiated by spermine at concentrations < 1 mM, and inhibited by Zn(2+) in a dose-dependent and voltage-independent manner. No marked difference was observed between Ts16 and control diploid neurons for any of these modulators with regard to IC(50) and EC(50) values or voltage dependency. Additionally, inhibition by the NR2B selective inhibitor, ifenprodil, was similar. These results demonstrate that NMDA-evoked currents are not altered in cultured embryonic Ts16 neurons and suggest that Ts16 neurons contain similar functional properties of NMDA receptors as diploid control neurons despite an increased level of NR2A expression.

Animals↗
PubMed2001

Association of left ventricular hypertrophy and aortic dilation in patients with acute thoracic aortic dissection.

This study was designed to evaluate the impact of left ventricular mass on aortic diameters in patients who presented with acute thoracic aortic dissection where aortic dilation is common. Retrospective review of transthoracic and transesophageal echocardiograms was conducted for 63 patients treated for acute thoracic aortic dissection and for 16 normal subjects who were comparable for gender prevalence, age, heart rate, and blood pressure. The diameter of the aortic root was measured by transthoracic echocardiography. Diameters of the ascending aorta, and of the aorta at locations of 25, 30, and 35 cm from the dental arch were measured by transesophageal echocardiography. The findings indicated that all aortic diameters were significantly larger in patients with aortic dissection. Patients with aortic dissection also presented with greater left ventricular mass indices (p<0.00001) than normal subjects. Fractional shortening and left atrial diameter measurements obtained in patients with aortic dissection were similar to those obtained in the control group. Overall, the left ventricular mass index exhibited univariate relationships with aortic root diameter (r=0.27, p<0.02) and aortic diameters at 25 cm (r=0.51, p<0.00001), 30 cm (r=0.58, p<0.00001), and 35 cm (r=0.55, p<0.00001) distal to the arch but not with the diameter of the ascending aorta. After adjusting for gender, body mass index, history of hypertension and aortic dissection extent (Stanford types) by separate multivariate models, the authors found that the left ventricular mass index was independently associated with aortic diameters at 25 cm (beta=0.32, p<0.001), 30 cm (beta=0.38, p<0.0001), and 35 cm (beta=0.34, p < 0.0005) distal to the arch. They conclude that left ventricular mass is independently associated with aortic arch and descending aorta diameters in patients with acute thoracic aortic dissection. Left ventricular hypertrophy may be considered a risk factor for aortic enlargement and subsequent dissection.

Acute Disease↗
PubMed2001

Epithelial-mesenchymal interactions and lung branching morphogenesis. Role of polyamines and transforming growth factor beta1.

Lung branching morphogenesis is a result of epithelial-mesenchymal interactions, which are in turn dependent on extracellular matrix composition and cytokine regulation. Polyamines have recently been demonstrated as able to modify chick embryo skin differentiation. In this work we have examined the effects of putrescine and spermidine during chick embryo lung morphogenesis in organotypic cultures by morphological, histochemical and biochemical examination. To verify the role of polyamines, we used specific inhibitors, such as bis-cyclohexylammonium sulphate and alfa-difluoromethylornithine, and transforming growth factor beta1, an ornithine decarboxylase and polyamine stimulator. Our data show that lung morphogenesis is significantly altered following the induced mesenchymal glycosaminoglycan changes. The increase of mesenchymal glycosaminoglycans is correlated with a stimulation of lung development in the presence of polyamines, and with its inhibition when transforming growth factor beta1 is added to the culture medium. The morphometric data show a uniform increase of both the mesenchyme and epithelial branching with spermidine and putrescine stimulus, whereas the mesenchymal substance alone is significantly increased in apical-median lung sections with transforming growth factor beta1 and transforming growth factor beta1 + spermidine lung cultures. Transforming growth factor beta1 and transforming growth factor beta1 + spermidine confirm the blocking of epithelial branching formations and fibroblast activation, and show that polyamines are unable to prevent the blocking of epithelial cells due to the inhibitory effect of transforming growth factor beta1.

Animals↗
PubMed2000

Expansion of rare CD8+ CD28- CD11b- T cells with impaired effector functions in HIV-1-infected patients.

The decline in the number of CD4+ T cells in HIV-1-infected patients is known to be related to the increased number of CD8+CD28- T cells. In this paper, we show that CD8+CD28- T cells from HIV-positive patients have an impaired capability to interact with human endothelial cells. This is due to the dramatic expansion, within this subset, of rare CD11b- cells lacking cell-cell adhesion functions. In 50 HIV-positive patients, 19.5% +/- 6.5% of all T cells were CD8+CD28-CD11b-, whereas only 0.8% +/- 0.4% of all T cells from healthy donors showed this uncommon phenotype. The percentage of circulating CD8+CD28-CD11b- T cells was strongly related to the percentage of CD4+ T cells (r = -0.82). This population is peculiar in terms of HIV infection and was found to possess some characteristics associated with effector functions but its cytotoxic properties were impaired. The percentage of target cells lysed by CD8+CD28-CD11b- was significantly lower than that of cells lysed by its CD11b- counterpart (p <.05) both at low (5:1) or at relatively high (20:1) effector/target ratios. CD8+CD28-CD11b- T cells, which lack the ability to interact with endothelial cells, are likely to accumulate and persist in circulation. The biologic properties of CD8+CD28-CD11b- T cells suggest that these cells might be endstage or aberrant differentiated effector cells. Lack of cell-cell adhesion and impaired cytolytic functions favor the hypothesis of a role for CD8+CD28-CD11b- T cells in the development of immunodeficiency.

CD28 Antigens↗
PubMed2000

Differential production of IFN-gamma, analyzed at the single-cell level, by specific subsets of human NK and T cells from healthy and HIV(+) subjects.

BACKGROUND: Interferon gamma is a cytokine that plays a central role in immunity, and is physiologically secreted by T and NK cells under appropriate stimuli during the immune response. By means of flow cytometry, we performed a single cell analysis of interferon gamma producing NK cells and their surface phenotype in normal and HIV(+) individuals that show several defects of cytokine production and cellular immunity. METHODS: PBMC or purified NK cells were stimulated for 1-12 h with PMA/ionomycin in the presence of monensin, subsequently stained for surface CD56 and CD3 or CD8, and for intracytoplasmic IFN-gamma, and analysed by flow cytometry. RESULTS: Our results show that CD56(+) NK cells are more efficient interferon gamma producers than T cells. Moreover, within the CD56(+) NK cell population, those that co-express low density CD8 are the best producers. Finally, we show that NK cells during HIV infection are more massively recruited to interferon gamma production than those from normal subjects. CONCLUSIONS: Both in the normal and HIV(+) subjects, a higher percentage of NK cells than T cells can produce IFN-gamma although differences can be identified within the NK cells subset in terms of IFN-gamma production. The production of IFN-gamma is fully achievable in the HIV(+) subjects, which is consistent with their elevated plasmatic levels of the cytokine. The possibility that NK cells that produce interferon gamma could represent a functionally distinct population committed to the production of this cytokine, is discussed.

Antigens, CD↗
PubMed2000

Acute recurrent polyhydramnios and amniotic prolactin.

A 25 year-old patient in her third pregnancy presented with acute polyhydramnios at 24 weeks' gestation, which was the same time as in the two previous pregnancies. In both she had preterm premature rupture of membranes, preterm delivery and neonatal deaths. In the third pregnancy, amnioreductions combined with medical treatment resulted in the birth by Caesarean section of a normally formed live male at 31 weeks of pregnancy. Acute recurrent polyhydramnios is an extremely rare condition of unknown aetiology. We hypothesized that amniotic prolactin plays a role in this pathology. It was measured serially in amniotic fluid and high levels were found.

Acute Disease↗
PubMed2000

Antiphospholipid antibodies affect trophoblast gonadotropin secretion and invasiveness by binding directly and through adhered beta2-glycoprotein I.

OBJECTIVE: To investigate the in vitro ability of antiphospholipid antibodies (aPL) to bind human trophoblast cells and to affect gonadotropin secretion and invasiveness. METHODS: Antiphospholipid antibody IgG from women with recurrent miscarriages, beta2-glycoprotein I (beta2GPI)-independent IgG aPL human monoclonal antibody (mAb) (519), and IgM anti-beta2GPI human mAb (TMIG2) were investigated for their binding to trophoblasts cultured for various amounts of time, their ability to affect invasiveness of Matrigel-coated filters, and their release of human chorionic gonadotropin (hCG). RESULTS: Polyclonal IgG aPL, as well as mAb 519 and TMIG2, bound to trophoblasts, the highest binding being found when cells displayed the greatest amount of syncytium formation. TM1G2 binding was found to be betaGPI dependent. Both polyclonal and monoclonal aPL, but not the controls, significantly reduced hCG release and Matrigel invasiveness. CONCLUSION: These findings suggest that aPL recognition of both anionic PL and adhered beta2GPI on trophoblast cell structures might represent a potential pathogenetic mechanism for defective placentation in women with the antiphospholipid syndrome.

Anions↗
PubMed2000

Characterization of gammadelta T cells expressing CD158b, a killer cell inhibitory receptor, in a patient with chronic CD4(+) lymphocytopenia and disseminated Mycobacterium intracellulare infection.

A population of Vdelta1(+)Vgamma9(-) gammadelta T cells that represented almost the totality (84%) of circulating lymphocytes in a patient with chronic, non-HIV-related, CD4 lymphocytopenia complicated by a disseminated Mycobacterium intracellulare infection was characterized. These gammadelta(+) T cells expressed a single killer inhibitory receptor (CD158b) and their phenotype (CD8(+)CD57(+)CD27(-)CD28(-)) indicated that, although CD45RA(+), they were not naive. However, the absence of large granular lymphocyte morphology, the impaired proliferative activity, the high susceptibility to apoptosis, and the total lack of cytotoxic ability suggested that these gammadelta cells were in a resting state. A high percentage of the cells did not harbor the CD11b integrin alpha chain and exhibited a decreased capability to bind endothelial cells. This defect might represent the mechanism whereby they remained trapped in the circulation.

Antigens, CD↗