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4.
Eur Rev Med Pharmacol Sci ; 24(18): 9698-9704, 2020 Sep.
Article in English | MEDLINE | ID: mdl-33015815

ABSTRACT

OBJECTIVE: To investigate patient characteristics and factors that increase the risk of being admitted to intensive care and that influence survival in cases of SARS-CoV-2 pneumonia. PATIENTS AND METHODS: One-hundred and ninety-one SARS-CoV-2 patients were admitted to the "Fondazione Poliambulanza di Brescia" Hospital (Brescia, Lombardy, Italy) in the period 1st March 2020 to 11th April 2020. Data on demographics, clinical presentation at admission, co-morbidities, pharmacological treatment, admission to intensive care and death was recorded. Logistic regression and survival analysis were carried out to investigate the risk of being admitted to intensive care and the risk of death. RESULTS: The mean age of the study cohort was 64.6±9.9 years (range 20-88). Median BMI was 28.5±5 kg/m2. Fever (81%) and dyspnea (65%) were the most common symptoms on admission. Most of patients (63%) had at least one co-existing disease. The 157 (82%) patients admitted to intensive care were more likely to be of intermediate age (60-69 years; OR 3.23, 95% CI 1.32-8.38), overweight (OR 2.66, 95% CI 1.02-7.07) or obese (OR 5.63, 95% CI 1.73-21.09) and with lymphocytopenia (OR 2.75, 95% CI 1.17-6.89) than the 34 patients admitted to the ordinary ward. During intensive care, 50% of patients died and their death was associated with older age (HR 2.06, 95% CI 1.07-3.97), obesity (HR 2.23, 95% CI 1.15-4.35) and male gender (HR 1.9, 95% CI 1.02-3.57). CONCLUSIONS: We found that admission to intensive care and poor survival were associated with advanced age and higher body mass index, albeit with differences in statistical significance. Pre-existing diseases and symptoms on admission were not associated with different clinical outcomes. Interestingly, male gender was more prevalent among SARS-CoV-2 patients and was related negatively to survival, but it was not associated with more frequent admission to intensive care.


Subject(s)
Coronavirus Infections/mortality , Hospitalization/statistics & numerical data , Intensive Care Units/statistics & numerical data , Pneumonia, Viral/mortality , Adult , Age Factors , Aged , Aged, 80 and over , Betacoronavirus , COVID-19 , Female , Humans , Italy , Male , Middle Aged , Pandemics , Risk Factors , SARS-CoV-2 , Sex Factors , Young Adult
5.
Clin Immunol ; 218: 108525, 2020 09.
Article in English | MEDLINE | ID: mdl-32659374

ABSTRACT

The presence of large granular lymphocytes has been reported in patients with ADA2 deficiency and T-LGL leukemia. Here we describe two siblings with novel ADA2 variants, expanding the mutational spectrum of ADA2 deficiency. We show that lymphoproliferation, persistence of large granular lymphocytes, T-cell perturbations, and activation of PI3K pathway, measured by means of phosphorylation levels of S6, are detectable in DADA2 patients without T-LGL leukemia.


Subject(s)
Adenosine Deaminase/deficiency , Adenosine Deaminase/genetics , Immunologic Deficiency Syndromes/genetics , Immunologic Deficiency Syndromes/immunology , Intercellular Signaling Peptides and Proteins/deficiency , Intercellular Signaling Peptides and Proteins/genetics , Lymphocytes/immunology , Child , Genetic Variation , Humans , Male , Siblings
8.
Hum Immunol ; 73(8): 836-9, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22627058

ABSTRACT

Common variable immunodeficiency (CVID) is a primary immune disorder characterized by low immunoglobulin serum levels and increased susceptibility to infections. Underlying genetic causes are only known in less than 15% of patients and encompass mutations in the genes encoding for ICOS, TACI, BAFF-R, CD19, CD20, CD81 and MSH5. TACI is the most frequently mutated gene among CVID patients. We report on two pediatric Italian male siblings with hypogammaglobulinemia and recurrent respiratory and gastrointestinal infections in association with a novel compound heterozygous TACI mutation. Both patients carry the I87N/C104R mutation that has not been reported yet. This results in aberrant TACI expression and abrogates APRIL binding on EBV B cells. This study identifies a novel combined mutation in TNFRSF13B increasing the spectrum of TACI mutations associated with CVID.


Subject(s)
Agammaglobulinemia/genetics , Common Variable Immunodeficiency/genetics , Respiratory Tract Infections/genetics , Transmembrane Activator and CAML Interactor Protein/genetics , Agammaglobulinemia/complications , Agammaglobulinemia/immunology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , B-Lymphocytes/pathology , Base Sequence , Child , Common Variable Immunodeficiency/complications , Common Variable Immunodeficiency/immunology , Genes, Recessive , Genetic Predisposition to Disease , Heterozygote , Humans , Male , Molecular Sequence Data , Mutation , Pedigree , Respiratory Tract Infections/complications , Respiratory Tract Infections/immunology , Transmembrane Activator and CAML Interactor Protein/metabolism , Tumor Necrosis Factor Ligand Superfamily Member 13/metabolism
9.
J Investig Allergol Clin Immunol ; 21(5): 348-53, 2011.
Article in English | MEDLINE | ID: mdl-21905497

ABSTRACT

BACKGROUND AND OBJECTIVE: The candidate gene approach has led to the detection of associations between common variable immunodeficiency (CVID) and mutations in the genes TACI, ICOS, BAFF-R, CD19, CD20, and CD81. Such mutations are present in less than 15% of cases, highlighting the complexity of the disease. Animal models for 2 genes involved in B-cell development, namely CARMA1/CARD11 and Bob1, develop an immunological phenotype similar to that seen in CVID, with low immunoglobulin serum levels, defective responses to antigen, and defective B-cell activation. The aim of this study was to evaluate CARMA1/CARD11 and Bob1 as candidate genes for the pathogenesis of CVID in a cohort of 66 patients with the disease. PATIENTS AND METHODS: We performed direct gene sequencing of CARMA1/CARD11 and Bob1 in 66 patients with CVID. RESULTS: Seven already reported genetic variants and 4 novel ones were found in the CARMA1/CARD11 gene, while 1 already reported variant and 1 novel variant were found in the Bob1 gene. CONCLUSIONS: Although novel genetic variants were identified in both the CARMA1/CARD11 and the Bob1 gene, no disease-causing mutations were identified in our group of patients. However, 4 of the variants in CARMA1 and 1 of those in Bob1 were associated with the disease. Considering the heterogeneity and complexity of CVID, further studies are needed to better define the genetic mechanisms involved in the pathogenesis of the disease.


Subject(s)
B-Lymphocytes/metabolism , CARD Signaling Adaptor Proteins/metabolism , Common Variable Immunodeficiency/genetics , Guanylate Cyclase/metabolism , Trans-Activators/metabolism , B-Lymphocytes/immunology , B-Lymphocytes/pathology , CARD Signaling Adaptor Proteins/genetics , Cell Differentiation/genetics , Common Variable Immunodeficiency/immunology , Common Variable Immunodeficiency/physiopathology , DNA Mutational Analysis , Gene Frequency , Genetic Association Studies , Genetic Predisposition to Disease , Guanylate Cyclase/genetics , Humans , Italy , Lymphocyte Activation/genetics , Mutation/genetics , Polymorphism, Single Nucleotide , Trans-Activators/genetics , Trans-Activators/immunology
10.
Clin Exp Immunol ; 164(3): 381-7, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21488866

ABSTRACT

We were interested in the question of whether the congenital lack of B cells actually had any influence on the development of the T cell compartment in patients with agammaglobulinaemia. Sixteen patients with X-linked agammaglobulinaemia (XLA) due to mutations in Btk, nine patients affected by common variable immune deficiency (CVID) with <2% of peripheral B cells and 20 healthy volunteers were enrolled. The T cell phenotype was determined with FACSCalibur and CellQuest Pro software. Mann-Whitney two-tailed analysis was used for statistical analysis. The CD4 T cell memory compartment was reduced in patients with XLA of all ages. This T cell subset encompasses both CD4(+)CD45RO(+) and CD4(+)CD45RO(+)CXCR5(+) cells and both subsets were decreased significantly when compared to healthy controls: P = 0·001 and P < 0·0001, respectively. This observation was confirmed in patients with CVID who had <2% B cells, suggesting that not the lack of Bruton's tyrosine kinase but the lack of B cells is most probably the cause of the impaired CD4 T cell maturation. We postulate that this defect is a correlate of the observed paucity of germinal centres in XLA. Our results support the importance of the interplay between B and T cells in the germinal centre for the activation of CD4 T cells in humans.


Subject(s)
B-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/metabolism , Common Variable Immunodeficiency/immunology , Adolescent , Adult , Agammaglobulinaemia Tyrosine Kinase , Agammaglobulinemia/diagnosis , Agammaglobulinemia/genetics , Agammaglobulinemia/immunology , B-Lymphocytes/immunology , B-Lymphocytes/pathology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/pathology , Cell Differentiation , Cell Separation , Child , Common Variable Immunodeficiency/diagnosis , Common Variable Immunodeficiency/genetics , Female , Flow Cytometry , Genetic Diseases, X-Linked/diagnosis , Genetic Diseases, X-Linked/genetics , Genetic Diseases, X-Linked/immunology , Humans , Immunologic Memory , Leukocyte Common Antigens/biosynthesis , Lymphocyte Depletion , Male , Middle Aged , Mutation/genetics , Protein-Tyrosine Kinases/genetics , Receptors, CXCR5/biosynthesis
11.
Minerva Med ; 97(1): 47-50, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16565698

ABSTRACT

AIM: In spite of the diffusion of endoscopic treatment, mortality rate due to peptic ulcer haemorrhage (PUH) remains high. Helicobacter pylori (H. pylori) infection and nonsteroidal anti-inflammatory drugs (NSAIDs) are the 2 main aetiological factors, but their interactive role is controversial. The aim of this study was to determine both the prevalence of H. pylori infection and NSAIDs consumption in PUH and their prognostic importance. METHODS: In a prospective study, 41 consecutive patients (33 males, 8 females) admitted for PUH were recruited. H. pylori status was investigated both by measuring specific antibodies in serum and by histological detection on gastric biopsies obtained after one month from bleeding. In case of doubt, either a 13C urea breath test, or a stool antigen test were associated. All patients were treated with medical therapy associated to endoscopic treatment in most severe cases. RESULTS: Sixteen patients were infected from H. pylori (group A), 12 had a history of NSAIDs consumption (group B), and 13 had both risk factors (group C). The median duration of hospitalisation was 7 days for each group and correlated with age (P<0.04). Severity of PUH (high risk of rebleeding) was higher in group A (13/16; 81%) and group C (9/13; 69%), with respect to group B (6/12; 50%). This difference was not significant. CONCLUSIONS: H. pylori infection has a predominant role in causing PUH as well as in the prognosis and clinical course of this condition. Hence, it is important to determine H. pylori status in every patient with PUH.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/adverse effects , Helicobacter Infections/complications , Helicobacter pylori , Peptic Ulcer Hemorrhage/etiology , Adult , Aged , Aged, 80 and over , Female , Helicobacter pylori/isolation & purification , Humans , Male , Middle Aged , Peptic Ulcer Hemorrhage/chemically induced , Peptic Ulcer Hemorrhage/microbiology , Prospective Studies
12.
Dig Liver Dis ; 38(7): 511-4, 2006 Jul.
Article in English | MEDLINE | ID: mdl-16169299

ABSTRACT

Patients with the clinical syndrome of visceral larva migrans as a result of Toxocara species, have typical lesions in the liver consisting of granulomas that contain numerous eosinophils and often Charcot-Leyden crystals. This syndrome is rarely taken into account in patients with cholestatic syndrome, especially when hypereosinophilic reaction is absent. We report the case of a 47-year-old immunocompetent woman who presented with abdominal pain, in whom multiple focal liver lesions were discovered. She had come in contact with dogs. Diagnosis of toxocariasi was done. A good clinical response has been obtained by treating with thiabendazole. We present the findings of various imaging studies of the patient. This report shows that visceral larva migrans may be the cause of a chronic liver disease and should be suspected also in patients without fever and hypereosinophilia with cryptogenic cholestatic and focal liver lesions.


Subject(s)
Larva Migrans/pathology , Larva Migrans/parasitology , Liver Diseases, Parasitic/pathology , Liver Diseases, Parasitic/parasitology , Toxocara canis/physiology , Toxocariasis/pathology , Toxocariasis/parasitology , Animals , Female , Humans , Image Processing, Computer-Assisted , Larva Migrans/diagnostic imaging , Liver Diseases, Parasitic/diagnostic imaging , Magnetic Resonance Imaging , Middle Aged , Radiography , Radionuclide Imaging , Toxocariasis/diagnostic imaging
13.
J Med Microbiol ; 53(Pt 5): 381-387, 2004 May.
Article in English | MEDLINE | ID: mdl-15096546

ABSTRACT

In order to determine whether there is an association between the presence of Epstein-Barr virus (EBV) and mycosis fungoides (MF) disease progression, PCR was performed to detect the EBV status of 20 MF patients; six EBV-positive patients were found. EBV variants may differ in their biological properties, such as their ability to transform cells; therefore, the ability of these variants to immortalize B cells in vitro was analysed. Six continuously growing cell lines were obtained from prolonged cultures of unstimulated peripheral blood mononuclear cells that were taken from the six EBV-positive patients with MF. In order to characterize the EBV strains, EBNA-2 and LMP-1/LMP-2 gene polymorphisms in the six cell lines were also analysed. All patients were followed up for 10 years and it was noticed that EBV-positive patients had a poor prognosis with rapid disease progression and high mortality rates, compared to EBV-negative patients. EBV may therefore constitute a co-factor that accelerates the progression of disease.


Subject(s)
B-Lymphocytes/virology , Herpesvirus 4, Human/genetics , Mycosis Fungoides/virology , Polymorphism, Genetic , Aged , Aged, 80 and over , Amino Acid Sequence , Cell Line, Transformed , Cell Transformation, Viral , Cells, Cultured , Cysteine Endopeptidases/chemistry , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Epstein-Barr Virus Nuclear Antigens/genetics , Epstein-Barr Virus Nuclear Antigens/metabolism , Female , Herpesvirus 4, Human/classification , Herpesvirus 4, Human/isolation & purification , Humans , Male , Middle Aged , Molecular Sequence Data , Mycosis Fungoides/physiopathology , Polymerase Chain Reaction , Viral Matrix Proteins/chemistry , Viral Matrix Proteins/genetics , Viral Matrix Proteins/metabolism , Viral Proteins
14.
Am J Gastroenterol ; 97(9): 2383-90, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12358261

ABSTRACT

OBJECTIVES: Several studies in human cirrhosis have demonstrated increased nitric oxide (NO) production. In experimental animals, intracerebroventricular administration of NO donors causes a marked depression of the endogenous dopaminergic activity, a function known to be physiologically recruited and exerting a natriuretic function in patients with compensated cirrhosis. The aim of this study is to evaluate the interaction between the systemic plasma levels of NO, the endogenous dopaminergic activity and the main parameters of renal function in patients with liver cirrhosis of differing degrees of severity. METHODS: A total of 21 patients (11 with preascitic and 10 with nonazotemic diuretic-free ascitic cirrhosis) and 10 healthy control subjects underwent the following tests: a) basal plasma renin activity (PRA) and aldosterone levels; b) renal clearances of sodium, potassium, inulin, para-minohippurate and lithium (the latter being a measure of the fluid delivery to the distal nephron); c) NO systemic plasma levels measured through paramagnetic resonance spectroscopy as nitrosylhemoglobin complexes; d) endogenous dopaminergic activity, evaluated by means of the incremental prolactin and aldosterone plasma levels after dopaminergic blockade with i.v. metoclopramide. RESULTS: NO plasma values and endogenous dopaminergic activity, although significantly increased with respect to healthy controls, were not different in the two groups of patients. The plasma NO/PRA ratio was significantly higher in the group of compensated patients with respect to ascitic cirrhotics (respectively, 18.3 +/- 11.8 vs 3.5 +/- 2.6 A.U./ng/ml/h, p < 0.001). Compared with compensated cirrhotics, patients with ascites showed significantly lower values of glomerular filtration rate (GFR) and renal plasma flow (RPF). Interestingly, GFR values were substantially the same in the ascitic patients and the control subjects. Compensated patients displayed a significant positive correlation between metoclopramide-induced incremental aldosterone plasma levels (i.e., endogenous dopaminergic tone) and fractional excretion of sodium (r = 0.58; p < 0.05). In the group of compensated patients, NO levels correlated inversely with creatinine plasma concentrations (r = -0.85; p < 0.001) and directly with inulin clearance (r = 0.65; p < 0.05). CONCLUSIONS: These data show that, at least in compensated cirrhotic patients, the stimulation of systemic NO production and the increased dopaminergic function may be mechanisms preventing renal perfusion, GFR, and fractional excretion of sodium from precocious reductions.


Subject(s)
Kidney/physiopathology , Liver Cirrhosis/blood , Liver Cirrhosis/physiopathology , Nitric Oxide/blood , Receptors, Dopamine/physiology , Uremia/blood , Uremia/physiopathology , Vasodilator Agents/blood , Adult , Female , Humans , Kidney Tubules/physiopathology , Liver Cirrhosis/complications , Male , Middle Aged , Severity of Illness Index , Uremia/complications
15.
Dig Dis Sci ; 47(2): 401-4, 2002 Feb.
Article in English | MEDLINE | ID: mdl-11855558

ABSTRACT

The use of angiotensin II antagonists in the treatment of portal hypertension remains controversial. Our aims were to assess the effect of Irbesartan on portal pressure and to evaluate its safety in cirrhotic patients with portal hypertension. Twenty-five cirrhotic patients were treated in a pilot study with Irbesartan 300 mg orally once daily for 60 days. Hemodynamic evaluations and biochemical tests were performed before therapy and after two months of treatment. Three patients (12%) discontinued treatment for symptomatic arterial hypotension (mean arterial pressure -26.% +/- 3.1 versus basal). In the 18 responders, the hepatic venous pressure gradient diminished by a mean of 18.1% +/- 10.5 from baseline (p = 0.02); the gradient decreased by 20% or more in only 5 patients (23%). The mean arterial pressure decreased significantly during therapy (92 +/- 7 vs 109 +/- 25 mm Hg, P < 0.001). In conclusions, Irbesartan induced a marginal reduction in portal pressure and its safety was limited by the pronounced effects on arterial pressure.


Subject(s)
Angiotensin Receptor Antagonists , Antihypertensive Agents/therapeutic use , Biphenyl Compounds/therapeutic use , Hypertension, Portal/drug therapy , Liver Cirrhosis/complications , Tetrazoles/therapeutic use , Antihypertensive Agents/adverse effects , Biphenyl Compounds/adverse effects , Female , Hemodynamics/drug effects , Humans , Hypertension, Portal/complications , Irbesartan , Male , Middle Aged , Pilot Projects , Portal Pressure/drug effects , Tetrazoles/adverse effects
16.
Int J Cancer ; 94(3): 314-21, 2001 Nov 01.
Article in English | MEDLINE | ID: mdl-11745408

ABSTRACT

Retinoids are a class of natural or synthetic compounds that participate in the control of cell proliferation, differentiation and fetal development. The synthetic retinoid fenretinide (HPR) inhibits carcinogenesis in various animal models. Retinoids have also been suggested to be effective inhibitors of angiogenesis. The effects of HPR on certain endothelial cell functions were investigated in vitro, and its effects on angiogenesis was studied in vivo, by using the chorioallantoic membrane (CAM) assay. HPR inhibited vascular endothelial growth factor- (VEGF-) and fibroblast growth factor-2- (FGF-2)-induced endothelial cell proliferation without affecting endothelial motility; moreover, HPR inhibited growth factor-induced angiogenesis in the CAM assay. Furthermore, a significant antiangiogenic potential of HPR has also been observed in neuroblastoma (NB) biopsy-induced angiogenesis in vivo. We previously demonstrated that supernatants derived from NB cell lines stimulated endothelial cell proliferation. In the present study, we found that this effect was abolished when NB cells were incubated in the presence of HPR. VEGF- and FGF-2-specific ELISA assays, performed on both NB cells derived from conditioned medium and cellular extracts, indicated no consistent effect of HPR on the level of these angiogenic cytokines. Moreover, RT-PCR analysis of VEGF and FGF-2 gene expression confirmed the above lack of effect. HPR was also able to significantly repress the spontaneous growth of endothelial cells, requiring at least 48-72 hr of treatment with HPR, followed by a progressive accumulation of cells in G(1) at subsequent time points. Finally, immunohistochemistry experiments performed in the CAM assay demonstrated that endothelial staining of both VEGF receptor 2 and FGF-2 receptor-2 was reduced after implantation of HPR-loaded sponges, as compared to control CAMs. These data suggest that HPR exerts its antiangiogenic activity through both a direct effect on endothelial cell proliferative activity and an inhibitory effect on the responsivity of the endothelial cells to the proliferative stimuli mediated by angiogenic growth factors.


Subject(s)
Anticarcinogenic Agents/pharmacology , Antineoplastic Agents/pharmacology , Fenretinide/pharmacology , Neovascularization, Pathologic , Neuroblastoma/blood supply , Neuroblastoma/drug therapy , Adenocarcinoma/blood supply , Adrenal Glands/blood supply , Animals , Cell Cycle , Cell Division , Cell Line , Cell Movement , Chick Embryo , Chorion , Endometrial Neoplasms/blood supply , Endothelial Growth Factors/metabolism , Endothelium/cytology , Enzyme-Linked Immunosorbent Assay , Female , Fibroblast Growth Factor 2/metabolism , Flow Cytometry , Humans , Immunohistochemistry , Kinetics , Lymphokines/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Time Factors , Tumor Cells, Cultured , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
17.
Nephrol Dial Transplant ; 16(12): 2328-36, 2001 Dec.
Article in English | MEDLINE | ID: mdl-11733624

ABSTRACT

BACKGROUND: Primary Sjögren's syndrome is a connective tissue disorder affecting primarily the lacrimal and salivary glands, resulting in xerophtalmia and xerostomia. Extraglandular manifestations are frequent and may include renal involvement. METHODS: We studied the prevalence and nature of kidney involvement in 60 Italian patients with primary Sjögren's syndrome, diagnosed according to the European classification criteria. The following renal laboratory tests were performed in all patients: electrolytes in serum and in 24-h urine, creatinine in serum and in 24-h urine, venous pH and HCO(3)(-), urinalysis, urine culture, urinary osmolality and urine pH. A water deprivation test was performed in patients with morning urine osmolalities below the reference values adjusted for age. An oral ammonium chloride loading test was performed in patients with urine pH above 5.5 from morning samples. Renal biopsy was performed in patients with renal involvement. RESULTS: Sixteen patients (27%) had laboratory evidence of tubular and/or glomerular dysfunction. A variable degree of creatinine clearance reduction was found in eight patients (13%); frank distal tubular acidosis in three (5%); hypokalaemia in four (7%); and pathological proteinuria in 12 (20%). Urine concentrating capacity was defective in 10 out of 48 (21%) tested patients. Only four patients presented with overt clinical manifestations, including hypokalaemic tetraparesis (1), nephrotic syndrome (2), recurrent renal stones with flank pain and haematuria (1). In two patients, signs of renal involvement preceded the onset of sicca syndrome. Renal biopsies from nine patients showed tubulo-interstitial nephritis in six and glomerular disease in three. Patients with renal involvement had a significantly shorter disease duration compared with patients without renal abnormalities. CONCLUSIONS: Kidney involvement is a frequent extraglandular manifestation of primary Sjögren's syndrome. It is rarely overt and may precede the onset of subjective sicca syndrome.


Subject(s)
Kidney/pathology , Kidney/physiopathology , Sjogren's Syndrome/pathology , Sjogren's Syndrome/physiopathology , Adult , Aged , Aged, 80 and over , Female , Humans , Kidney Function Tests , Kidney Tubules/physiopathology , Male , Middle Aged
18.
Lab Invest ; 81(6): 875-85, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11406648

ABSTRACT

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.


Subject(s)
Aorta/embryology , Endothelium, Vascular/cytology , Neovascularization, Physiologic/physiology , Stem Cells/cytology , Antigens, CD34/metabolism , Cell Separation , Embryo, Mammalian/metabolism , Embryo, Mammalian/physiology , Embryonic and Fetal Development , Endothelium, Vascular/metabolism , Flow Cytometry , Humans , Immunohistochemistry , Stem Cells/metabolism
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