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Biomedical subjects

A Caruso

Publications and source records attributed to A Caruso.

At least 91 records · Page 5Linked to original sources
PubMed1999

Genomic-sequence comparison of two unrelated isolates of the human gastric pathogen Helicobacter pylori.

Helicobacter pylori, one of the most common bacterial pathogens of humans, colonizes the gastric mucosa, where it appears to persist throughout the host's life unless the patient is treated. Colonization induces chronic gastric inflammation which can progress to a variety of diseases, ranging in severity from superficial gastritis and peptic ulcer to gastric cancer and mucosal-associated lymphoma. Strain-specific genetic diversity has been proposed to be involved in the organism's ability to cause different diseases or even be beneficial to the infected host and to participate in the lifelong chronicity of infection. Here we compare the complete genomic sequences of two unrelated H. pylori isolates. This is, to our knowledge, the first such genomic comparison. H. pylori was believed to exhibit a large degree of genomic and allelic diversity, but we find that the overall genomic organization, gene order and predicted proteomes (sets of proteins encoded by the genomes) of the two strains are quite similar. Between 6 to 7% of the genes are specific to each strain, with almost half of these genes being clustered in a single hypervariable region.

Duodenal Ulcer↗
PubMed1999

Correlation between pulsed electromagnetic fields exposure time and cell proliferation increase in human osteosarcoma cell lines and human normal osteoblast cells in vitro.

We have exposed cultured bone cells to a pulsed electromagnetic field (PEMF) for different times to find the minimal exposure time necessary to stimulate an increase of DNA synthesis. We used two different human osteosarcoma cell lines, TE-85 and MG-63, and human normal osteoblast cell (NHOC) obtained from surgical bone specimens. The cells were placed in multiwell plates and set in a tissue culture incubator between a pair of Helmoltz coils powered by a pulse generator (1.3-ms pulse, repeated at 75 Hz) for different periods of time. [3H]Thymidine incorporation was used to evaluate cell proliferation. The two osteosarcoma cell lines increase their thymidine incorporation when exposed to a PEMF for at least 30 min, both in a medium containing 10% fetal calf serum and in a serum-free medium. NHOC are known to increase their cell proliferation when exposed to PEMF but only if cultured in the presence of 10% fetal calf serum. In this experimental condition, three of the four cell lineages studied required at least 9 h of PEMF exposure to increase their DNA synthesis, whereas one cell lineage increased its cell proliferation after 6 h of PEMF exposure. Our observations confirm the hypothesis that the proliferative responses of NHOC and human osteosarcoma cell lines to PEMF exposure are quite different. Moreover, NHOC required minimal exposure times to PEMF to increase their cell proliferation, similar to that needed to stimulate bone formation in vivo.

Adult↗
PubMed1999

Generation of CD28- cells from long-term-stimulated CD8+CD28+ T cells: a possible mechanism accounting for the increased number of CD8+CD28- T cells in HIV-1-infected patients.

According to CD28 molecule expression, CD8+ T cells can be classed as CD28bright, CD28dim, and CD28-. The CD28dim T cells were found to derive from mitogenic stimulated CD28-T cells but also from CD28bright T cells through a mechanism of CD28 down-modulation. Moreover, after prolonged in vitro interleukin-2 stimulation, clonal CD28bright, cells showed a CD28dim expression before further evolution to a stable CD28-phenotype. This loss was concomitant with the disappearance of CD28 mRNA. A study of the cytokine production pattern revealed that CD28dim and CD28- T cell clones produced similar levels of type 1 and type 2 cytokines, which differed from those produced by the CD28bright T cell clones. A high percentage of CD28dim and CD28- cells, with similarities in their cytokine production pattern, were found in the blood samples of HIV-infected patients, as compared to healthy donors. The CD28 down-modulation may account for the increased number of CD8+CD28- T cells in HIV-infected patients.

Adult↗
PubMed1999

Ontogeny of the fetal immune system: study on pregnancies with Rh-isoimmunization and nonimmune fetal hydrops.

This study aims at observing and comparing the antigen expression of some fetal T- and B-lymphocyte subpopulations in Rh-isoimmunization, which determines anemic hypoxia in the fetus, and nonimmune fetal hydrops (NIFH) which, even if there are some etiological factors involved, causes hipoxic hypoxia in the fetus. Twelve fetuses were studied by way of 30 fetal blood samples obtained by ultrasound-guided cordocentesis between the 20th and 36th gestational week. Twenty-four blood samples in all where taken from the eight fetuses with Rh-isoimmunization. Six blood samples were obtained from the four fetuses with NIFH. The lymphocyte phenotypes studied by monoclonal antibodies and flow cytometry were the following: CD3, CD4, CD8, expression of T-lymphocyte subpopulations; BsIg, CD19, expression of B-lymphocyte subpopulations. We observed a near-normal maturation process in fetuses with Rh isoimmunization, whereas in fetuses with NIFH we observed inhibition and/or delayed expression of T-lymphocytes. An early and increased B-lymphocyte activation marked a cooperation between the two systems in the early gestational periods.

Anemia↗
PubMed1999

Effects of pulsed electromagnetic fields on human chondrocytes: an in vitro study.

(3)H-thymidine incorporation was studied in cultured human nasal and articular chondrocytes exposed to low-energy, low-frequency pulsed electromagnetic fields (PEMFs) (75 Hz, 2.3 mT). The reverse transcriptase polymerase chain reaction (RT-PCR) analysis shows that human secondary chondrocytes derived from both nasal and articular cartilage express collagen type II mRNA, which is a specific marker of the chondrocyte phenotype. In a preliminary series of experiments, cells were exposed to PEMF for different time periods ranging from 6 to 30 hours (time-course), in medium supplemented with 10% or 0.5% fetal calf serum (FCS) and in serum-free medium. The ratios between the (3)H-thymidine incorporation in PEMFs and control cultures show an increase of the cell proliferation in cultures exposed to PEMFs when serum is present in the culture medium, whereas no effect was observed in serum-free conditions. The increase in DNA synthesis, induced by PEMFs, was then evaluated only at the times of maximum induction and the results were analyzed by the three-factor analysis of variance (ANOVA). The data presented in this study show that even if (3)H-thymidine incorporation is higher in nasal than in articular chondrocytes, PEMF induce an increase in the proliferation of both cell types. Moreover, the concentration of FCS in the culture medium greatly influences the proliferative response of human chondrocytes to the PEMF exposure. Though normal human osteoblast cells increase their proliferation when exposed to PEMFs if only 10% FCS is present in the medium, human chondrocytes are able to increase their cell proliferation when exposed to PEMFs in the presence of both 0.5% and 10% of FCS in the medium. The results obtained may help to explain the basic mechanisms of PEMF stimulation of fracture healing.

Adolescent↗
PubMed1999

Expression of inducible nitric oxide synthase in human granulomas and histiocytic reactions.

Inducible nitric oxide synthase (iNOS) is required in immune response against infections and is involved in granuloma formation in animals; in murine macrophages, iNOS is induced by lipopolysaccharide and interferon-gamma. In contrast, the role of iNOS in human immune response against infections is still questioned, and its expression in granulomas is poorly investigated. Using Western blotting and immunohistochemistry, we investigated iNOS expression in human lymph nodes with nonspecific reactions and in tissues containing granulomas caused by mycobacteria, Toxoplasma, Cryptococcus neoformans, Leishmania, Bartonella, noninfectious granulomas (sarcoidosis, foreign body), and other hystiocitic reactions (Kikuchi's disease, Omenn syndrome). iNOS was undetectable in nonspecific reactive lymphadenitis, foreign-body granulomas, and Omenn syndrome, whereas it was strongly expressed in infectious granulomas, sarcoidosis, and Kikuchi's diseases. Immunohistochemistry demonstrated that iNOS was selectively expressed by the epithelioid and multinucleated giant cells within the granulomas. Use of an anti-nitrotyrosine antibody, recognizing nitrosilated amino acid residues derived from nitric oxide production, revealed a consistent positivity within the cells expressing iNOS, thus suggesting that iNOS is functionally active. Detection of cytokines by reverse transcriptase-polymerase chain reaction demonstrated that tissues that were positive for iNOS, also expressed the Thl-type cytokine interferon-gamma mRNA, but not the Th2-type cytokine interleukin-4. Taken together, these results indicate that iNOS is involved in different human immune reactions characterized by histiocytic/granulomatous inflammation and associated with Th1-type cytokine secretion.

Adult↗
PubMed1999

Influence of body mass on the hypothalamic-pituitary-adrenal-axis response to naloxone in patients with polycystic ovary syndrome.

OBJECTIVE: To evaluate the influence of body mass on the hypothalamic-pituitary-adrenal (HPA)-axis response to naloxone in polycystic ovary syndrome (PCOS). DESIGN: Controlled clinical study. SETTING: Academic research environment. PATIENT(S): Ten lean and 10 obese women with PCOS compared with 7 lean and 8 obese control subjects matched for body mass index. INTERVENTION(S): Each patient received an IV bolus of naloxone at a dosage of 125 microg/kg. MAIN OUTCOME MEASURE(S): Samples were collected 30 minutes before and 0, 15, 30, 60, 90, and 120 minutes after injection: ACTH and cortisol levels were measured in all plasma samples. RESULT(S): No significant differences were found in the ACTH and cortisol responses to opioid blockade between lean women with PCOS and lean as well as obese control subjects; conversely, obese patients with PCOS showed a higher ACTH and cortisol responses to naloxone compared with all other groups. CONCLUSION(S): Hypothalamic-pituitary-adrenal-axis abnormalities of PCOS may be central in origin and abdominal obesity seems to play a key role in the HPA-axis hyperactivity of women with PCOS when naloxone is administered.

Adrenocorticotropic Hormone↗
PubMed1999

Antiinflammatory activity of adrenomedullin in the acetic acid peritonitis in rats.

The antiinflammatory effect of ADM was studied in different models of inflammation and compared to the one of CGRP. Peptides were active against acetic acid-induced peritonitis in the rats. ADM and CGRP exerted the antiinflammatory effect at different doses, 400 and 20 ng/kg respectively, but with different efficacy (ADM >CGRP). This effect was blocked by pretreatment with CGRP (8-37) fragment or with L-NAME. No antiinflammatory activity was evidenced against serotonin- or carrageenin-induced rat paw edema. Our data suggest that ADM exerts antiinflammatory activity in the model characterized by a vascular component. This effect involves CGRP receptors and appears to be mediated by nitric oxide system.

Acetic Acid↗
PubMed1999

Impact of insulin and body mass index on metabolic and endocrine variables in polycystic ovary syndrome.

To assess the differential impact of the insulin secretory pattern and obesity on the endocrinometabolic features of the polycystic ovary syndrome (PCOS), we studied 110 PCOS women. Patients underwent a gonadotropin-releasing hormone (GnRH) test, an oral glucose tolerance test (OGTT), and basal evaluation of hormonal and biochemical parameters. Basal androgens and lipids, basal and stimulated gonadotropins, insulin, and glucose levels were measured. Patients were classified into four groups according to the body mass index (BMI) and insulin secretion: normoinsulinemic-lean ([NL] n = 24), normoinsulinemic obese ([NO] n = 24), hyperinsulinemic lean ([HL] n = 17), hyperinsulinemic obese ([HO] n = 45). HL patients showed a higher luteinizing hormone (LH) area under curve (AUC) after GnRH stimulus compared with NL patients (HL v NL, 4,285 +/- 348 v 3,377 +/- 314 IU/L x 120 min, P < .05), whereas we failed to find a statistically significant difference in a similar comparison among obese subjects (HO v NO, 3,606 +/- 302 v 3,129 +/- 602 IU/L x 120 min). A trend toward increased plasma testosterone and decreased sex hormone-binding globulin (SHBG) was found in relation to hyperinsulinemia and obesity, thus resulting in a higher free androgen index (FAI) in groups HL and NO versus NL (HL, 5.54 +/- 0.51; NO, 5.64 +/- 0.49; NL, 4.13 +/- 0.33; P < .05 and P < .01, respectively). The presence of both exaggerated insulin secretion and obesity resulted in a synergistic additive effect on the FAI in the HO group (6.81 +/- 0.34). Concerning the lipoprotein lipid profile, the NL group showed lower plasma triglyceride levels compared with the other three groups, whereas no significant differences were found for nonesterified fatty acid (NEFA) concentrations. Higher low-density lipoprotein cholesterol (LDL-C) and very-low-density lipoprotein cholesterol (VLDL-C) and lower high-density lipoprotein cholesterol (HDL-C) levels were found in the obese groups compared with the lean counterparts, whereas the same parameters did not significantly differ in a comparison between normoinsulinemic and hyperinsulinemic groups. In conclusion, our data suggest an important role of hyperinsulinemia in the LH response to a GnRH stimulus and an independent and synergistic additive effect of obesity and hyperinsulinemia on the FAI in PCOS.

Adolescent↗
PubMed1999

Carbohydrate metabolism in gestational diabetes: effect of chronic hypertension.

OBJECTIVE: To evaluate whether the coexistence of chronic hypertension and gestational diabetes mellitus (GDM) is characterized by a greater impairment of carbohydrate metabolism than GDM alone. METHODS: Carbohydrate metabolism of eight women with chronic hypertensive GDM and 15 normotensive women with GDM was evaluated in the third trimester using the oral glucose tolerance test (GTT) and hyperinsulinemic-euglycemic clamp technique. Controls were ten normotensive, glucose-tolerant, pregnant women in the third trimester. RESULTS: Insulin sensitivity of women with chronic hypertension and GDM was approximately twofold lower than those with GDM only (1.54+/-0.35 versus 4.15+/-0.31, P < .001) and approximately fivefold lower than controls (1.54+/-0.35 versus 7.65+/-0.66, P < .001). Women with chronic hypertension and concomitant GDM had higher insulin levels in response to GTT than controls (P < .001 repeated measures analysis of variance). In all subjects, mean arterial pressure (MAP) had a strong negative correlation with maternal insulin sensitivity (r = -0.62, P < .001). Significant correlation was also found between percent of body fat and insulin sensitivity (r = -0.53, P < .002). Those regressions were still significant when adjusted for percent of body fat and MAP. CONCLUSION: Gravidas with chronic hypertension and GDM are more insulin resistant than those with GDM alone. Blood pressure, in a population of pregnant women with normal and abnormal carbohydrate metabolism, is a stronger predictor of insulin resistance than adiposity.

Adult↗
PubMed1999

Percutaneous mitral commissurotomy versus open mitral commissurotomy: a comparative study.

OBJECTIVE: Although many studies in medical literature are comparing percutaneous trans-septal mitral commissurotomy (PTMC) and open mitral commissurotomy (OMC), very few long-term comparative follow-ups are available. METHODS: Between January 1991 and December 1997, 193 patients with isolated mitral stenosis were assigned either to PTMC (111 cases) or to OMC (82 cases). PTMC was performed in all cases with Inoue Ballon, OMC was performed with standard techniques. Categorical values were compared by chi square analysis, whereas continuous data were compared by Mann-Whitney test. Univariate survival and event free analysis (Kaplan-Meier+/-SE and log rank) were performed. Recurrent stenosis was classified any mitral valve area (MVA) less than 1.2 cm2 and whenever post-op. echo showed a loss more than 50% of the initial gain. Data were reported as mean+/-SD. Data concerning late echocardiographic assessment were studied with linear and logistic regression analysis. RESULTS: The two groups were homogenous as far preoperative variables as sex, mean age, MVA, echo score and incidence of left atrial thrombosis were concerned. Mean NYHA was preoperatively higher in OMC (2.79+/-0.58) versus PTMC (2.42+/-0.5) (P = 0.001). There was no hospital mortality in both groups. Incidence of hospital complications was similar (4/ 111 after PTMC and 1/82 after OMC; P = 0.3). Seven year survival: 95.41+/-0.02 (PTMC) and 98.05+/-0.01 (OMC) (P = 0.3) and freedom from late complications did not show statistical differences: Embolism 98.78+/-0.01 in PTMC and 98.78+0.01 in OMC (P = 0.8); Recurrent stenosis 71.89+/-0.13 in PTMC versus 82.89+/-0.08 in OMC (P = 0.2); Reoperation 88.43+/-0.08 in PTMC versus 96.25+/-0.02 in OMC (P = 0.4). A larger MVA was found in patients undergone to OMC (2.05+/-0.35) versus PTMC (1.81+/-0.33) (P = 0.001). Furthermore mean NYHA was lower in OMC (1.14+/-0.3) versus PTMC (1.39+/-0.7) (P = 0.001). CONCLUSIONS: Both techniques achieve with a low operative risk and low incidence of complications a good palliation of rheumatic mitral stenosis. Incidence of complications in the follow-up is similar. OMC allows a larger mitral valve area, a better functional recovery and a lower incidence of late mitral regurgitation.

Adolescent↗
PubMed1999

Phenotypic and functional characteristics of tumour-derived microvascular endothelial cells.

We recently developed a method for the isolation and purification of tumour-derived endothelium. In this study the phenotypic and functional properties of human tumour-derived microvascular endothelial cells (TdMEC) were examined. Endothelium obtained from human adrenal gland specimens (HAMEC) was used as a reference microvascular endothelial cell population. TdMEC formed a confluent monolayer with the typical morphological appearance of endothelium and were positive for endothelial markers such as Ulex-1 lectin, CD31 antigen, von Willebrand Factor and VE-cadherin. The addition of acidic Fibroblast Growth Factor (aFGF), basic FGF (bFGF) or Vascular Endothelial Growth Factor (VEGF) substantially improved proliferation of TdMEC; and kidney carcinoma derived endothelial cells were more responsive to FGFs, whereas glioblastoma derived endothelial cells greatly responded to VEGF TdMEC expressed high levels of the VEGF receptors, KDR/flk-1 and Flt-1, as shown by northern blot analysis. TdMEC expressed the adhesion molecules ICAM-1, VCAM-1 and E-selectin that could be further increased by exposing TdMEC culture to interleukin-1. All the TdMEC expressed interleukin-8 mRNA. These findings show that TdMEC in vitro maintain several of the features described for microvasculature. Thus, TdMEC represent a useful tool to study markers for tumor vasculature.

Antigens, CD↗
PubMed1999

GFAPbeta mRNA expression in the normal rat brain and after neuronal injury.

GFAPbeta mRNA is an alternative transcript of the glial fibrillary acidic protein (GFAP) gene, whose transcriptional start site is located 169 nucleotides upstream to the classical GFAPalpha mRNA. By an RT-PCR method with primers on separate exons, we were able to confirm the presence of GFAP transcripts with a longer 5' untranslated region in all the examined areas of rat brain and in primary cultures of astroglial cells. Northern blot analysis, using an oligoprobe specific for the 5' region of GFAPbeta, revealed a single hybridization band of 2.9 kb in all the brain regions examined and in primary cultures of astroglial cells. The availability of the quantitative Northern blot assay allowed further studies on the regulation of GFAPbeta expression in vivo. Since it is well-known that neuronal brain injury is one of the most powerful inducers of GFAP, we examined the expression of GFAPalpha and beta after a neurotoxic lesion in the rat hippocampus. Results obtained show a parallel increase in both GFAP transcripts with an identical time-course, suggesting that regulatory regions of the gene influence in similar way the rate of transcription at the two different start sites (alpha and beta) or that a similar post-transcriptional mechanism is involved in regulating both mRNA isoforms.

Animals↗
PubMed1999

Reduced production of both Th1 and Tc1 lymphocyte subsets in atopic dermatitis (AD).

An imbalance of interferon-gamma (IFN-gamma)-bearing CD4+ T (Th1) cells in the pathogenesis of AD is well recognized; however, a possible role in AD for CD8+ T cells secreting Th1-like cytokines (Tc1) has not been properly addressed. In this study, two- and three-colour FACS analysis allowed us to discriminate the Th1 from the Tc1 subset. AD patients had half the number of IFN-gamma-producing circulating T cells (P < 0.005; 13.6 +/- 1.9% (mean +/- s.d.)) compared with normal donors (25.0 +/- 2.4%). Specifically, both Th1 (4.8 +/- 0.7%) and Tc1 (8.1 +/- 1.1%) cells in AD were decreased compared with Th1 (8.8 +/- 0.8%) and Tc1 (15.0 +/- 1.5%) cells in controls. Moreover, at the mRNA level, the ratios of IFN-gamma/IL-4 and IFN-gamma/IL-10 were lower in cells from AD patients compared with controls. In conclusion, the decrease of IFN-gamma-producing T lymphocytes in AD is due to a reduction in both Th1 and Tc1 IFN-gamma-secreting cells; this may not only contribute to the over-production of IgE, but also explain the high incidence of cutaneous infections observed in AD patients.

CD8-Positive T-Lymphocytes↗
PubMed1999

Gestational hypertension but not pre-eclampsia is associated with insulin resistance syndrome characteristics.

The aim of this study was to assess whether the metabolic characteristics of insulin resistance syndrome are present in pre-eclamptic (PE), gestational (GH) and chronic hypertensive (CH) pregnancies. Glucose and insulin serum concentrations, both fasting and after oral administration of a glucose tolerance test, were evaluated in 26 hypertensive pregnant women (10 PE, 10 GH and six CH patients) and in 10 healthy controls during the third trimester of gestation. Insulin sensitivity was assessed using the hyperinsulinaemic-euglycaemic clamp technique. The plasma concentrations of triglyceride (TG), high density (HDL), low density (LDL), and very low density (VLDL) lipoprotein cholesterol, apolipoproteins AI and B, and non-esterified fatty acid (NEFA) were also measured. Women with GH exhibited approximately 40% lower steady-state insulin sensitivity index (ISI) compared to controls (3.75 versus 6.34, P < 0.03), as well as approximately 33% higher mean plasma TG (3.57 versus 2.68 mmol/l, P < 0.01), and approximately 69% higher mean NEFA (0.59 versus 0.35 mmol/l, P < 0.01). Women with PE showed similar ISI but reduced insulin and glucose areas under curve compared to controls (P < 0.006, P < 0.0005 respectively). Women with PE also had higher HDL-cholesterol and apo-AI than controls. Patients with CH had similar lipid and carbohydrate metabolism to control subjects. In conclusion, women with GH exhibit metabolic features similar to those of patients with insulin resistance syndrome, suggesting that similar abnormalities could be involved in the pathogenesis of these disorders. In contrast, our data do not support an association between insulin resistance syndrome and hypertension in pregnant women with PE and chronic hypertension.

Adult↗