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Biomedical subjects

E Bruno

Publications and source records attributed to E Bruno.

At least 55 records · Page 3Linked to original sources
PubMed1996

Detection of a primitive megakaryocyte progenitor cell in human fetal bone marrow.

Ontogeny-related changes in megakaryocyte (MK) progenitor cells were a analyzed to further define the cellular hierarchy occurring during human MK development. CD34+ cells were selected from human low-density adult bone marrow (ABM) or unfractionated fetal bone marrow (FBM) and assayed for MK colony formation in a serum-depleted fibrin clot assay system. At days 3, 7, 12, 16, 21, and 28 of incubation, MK colonies were analyzed for colony number, size and number of foci of development. Unifocal CFU-MK-derived colonies cloned from FBM formed after fewer days of in vitro culture and were 2.6-fold larger than those colonies cloned from ABM, However, the frequency of CFU-MK derived colonies cloned from ABM was significantly greater. the MK colonies cloned from FBM morphologically consisted of both pure MK colonies and mixed MK-containing colonies, in which a core of CD41- cells were surrounded by CD41+MKs. Large colonies resembling the primitive burst-forming unit-MK (BFU-MK) also were assayable from both FBM and ABM. These BFU-MK-derived colonies appeared after fewer days of incubation when FBM was assayed compared to ABM, but at a significantly lower frequency. In addition, large unifocal MK colonies consisting of >300 cells (300-1000) appeared from cells cloned from FBM but not ABM. This type of colony, which appears to represent a unique type of MK progenitor cell, was termed a high proliferative potential cell-MK (HPPC-MK). such colonies represent a relatively rare MK progenitor. We conclude that there are a significant ontologic changes in human MK progenitor cell development. The kinetics of MK colony formation from ABM differs significantly from that of FBM. Furthermore, the proliferative capacity of fetal MK progenitor cells appear to be far greater than that of ABM. In addition, a more primitive lineage-restricted MK progenitor cell with extensive proliferative capacity, the HPPC-MK, was assayable exclusively from FBM.

Adult↗
PubMed1996

Fetal bone marrow CD34+CD41+ cells are enriched for multipotent hematopoietic progenitors, but not for pluripotent stem cells.

We have investigated the expression of CD41a (gpIIbIIIa) on a subpopulation of human fetal bone marrow (FBM) CD34+ progenitor cells. Human FBM CD34+Lin- cells were subfractionated into CD41a+ and CD41a- subpopulations by flow cytometry. All the megakaryocyte colony-forming cells (CFU-MK) and almost all the burst-forming units-megakaryocyte (BFU-MK) were found within the CD41a+ subpopulation. In addition, a 14-fold greater number of granulocyte-macrophage colony-forming units (CFU-GM) and a five-fold greater number of mixed lineage progenitor cells (CFU-mix) were observed within the CD34+Lin-CD41a+ subpopulation compared to the CD34+Lin-CD41a- subpopulation. The high proliferative potential of CD34+Lin-CD41a+ cells was demonstrated by their capacity to expand in in vitro culture containing human plasma and recombinant Mpl ligand (thrombopoietin [Tpo]) with production of over 80% CD41b+ (gpIIb+) MKs. However, in long-term bone marrow cultures, the CD34+Lin-CD41a- population contained a significantly higher frequency of cobblestone area-forming cells (CAFC) than the CD34+Lin-CD41a+ population, indicating the presence of a primitive hematopoietic stem cell (HSC) population within the CD34+Lin-CD41a- subset. These data suggest that fetal CD34+Lin-CD41a+ cells are enriched for MK progenitor cells (CFU-MK and BFU-MK), myeloid progenitors, and CFU-mix but do not contain the more primitive CAFC.

Antigens, CD34↗
PubMed1996

[Periapical lesions of mixed etiology: bacterial and foreign body].

After a review of the literature on periapical lesion pathogenesis, we studied histological, immunological, and bacteriological examinations of 10 overfilled teeth with periapical lesions. We found, in our research, a bacteriological etiology with foreign body reactions.

Bacteria↗
PubMed1996

[Giant cervical hyperostosis of the prevertebral space: presentation of two cases and review of the literature].

Swellings of the retropharyngeal area are quite rare and all cases have common symptoms deriving from the site of origin, size, interaction with the surrounding anatomical structures and the presence, or lack thereof, of any associated inflammation. The main symptoms are dysphagia, the feeling of a foreign body in the pharynx and dyspnea. The present work describes two clinical cases of hyperostosis of the cervical column both of which presented discrete dysphagia, intermittent dyspnea and swelling in the area located between the pharynx and the spinal column thus leading to the feeling of having a foreign body in the area. The first case was a hyperostosis of the prevertebral space located on the right side and running medially toward the homolateral palatine tonsil. The pharyngoepiglottic fold area was medialized while the glottic region appeared normal. The second case had an ovoid median swelling in the hypopharynx stemming from the prevertebral space. During normal respiration the upper part of the laryngeal face of the epiglottis came into contact with this swelling while during phonation the glottic plane was normal. CT, MRI and endoscopy all proved able to provide information regarding the anatomy of the neoformation and the relationship with the neighboring structures. Many surgical techniques have been described to gain access to the spinal column osteophytes. The transcervical techniques give better exposure than transoral approaches although they increase the risk of damaging the recurrent laryngeal nerve and the sympathetic nervous system; moreover they require marked retraction of the carotid artery. In the authors' experience surgery was opted for in only one of the cases as the patient was relatively young and in good general health. The transcervical posterolateral approach was chosen as it provided better exposure of the cervical region between C3 and C6 than did the anterolateral approach.

Aged↗
PubMed1995

Signal transduction by the receptors for thrombopoietin (c-mpL) and interleukin-3 in hematopoietic and nonhematopoietic cells.

Antisense oligonucleotide to the translation initiation sequence of human c-mpI reduced the proliferation of human CD34+ bone marrow cells in response to interleukin-3 (IL-3) alone or to the combination of IL-3 and thrombopoietin (TPO). To investigate the molecular basis for these cytokine interactions, we analyzed the relationship between the receptor subunits for IL-3 and TPO and determined whether both receptors activate identical signal transduction pathways. The function of the receptor subunits was characterized in transiently transfected hepatoma cells and fibroblasts by the activation of gene expression via specific regulatory elements and by the stimulation of DNA-binding activity of STAT proteins. Although c-mpl and IL-3 receptor (IL-3R) reconstituted a qualitatively comparable gene regulatory response, there was no detectable functional interaction between their respective receptor subunits. By comparing the receptor action in different cell lines, we observed that in human hepatoma cells the signaling of c-mpI was 100-fold less sensitive to TPO than in rat hepatoma cells. However, IL-3R signaling was comparable between the two cell types, suggesting that c-mpI and IL-3R do not use identical signal transducing mechanisms. The cytoplasmic domains necessary for c-mpI signaling were determined by testing deletion mutants. The membrane-proximal box 1 sequence motif was critical for gene regulation and for STAT protein activation that seemed to involve the Janus kinase 2 (JAK2). Because IL-3R was less dependent on JAK2 than c-mpI, different levels of JAK2 expression may account, in part, for the quantitative difference in IL-3 and TPO response among various cell lines.

Animals↗
PubMed1995

Granulocyte colony-stimulating factor induction of normal human bone marrow progenitors results in neutrophil-specific gene expression.

We have used a combination of hematopoietic growth factors to induce in vitro granulocytic maturation. A fraction of marrow cells enriched for hematopoietic progenitor cells (CD34+, HLA-DR+) was isolated from normal human bone marrow by monoclonal antibody staining and fluorescence-activated cell sorting. Cells were cultured in a suspension system for 3 days in the presence of stem cell factor and interleukin-3 (IL-3), after which granulocyte colony-stimulating factor (G-CSF) was added. Cells were harvested daily and analyzed for phenotypic maturation by morphologic criteria, and total RNA was obtained for analysis of myeloid gene expression. Maturation was observed to progress to the late metamyelocyte and band stage over a period of 10 to 12 days. Neutrophil-specific gene expression was assayed by reverse transcription-polymerase chain reaction (RT-PCR). Induction with G-CSF resulted in sequential expression of primary and secondary granule proteins, with asynchronous expression of primary granule proteins starting from days 1 to 5, and synchronous expression of lactoferrin and transcobalamin I (secondary granule proteins) from days 7 to 8. Interestingly, myeloperoxidase (MPO) mRNA expression was easily detected in both the freshly isolated CD34+, HLA-DR+ cells and cells at all subsequent stages of induction. This suggests that MPO mRNA is expressed very early during neutrophil development, perhaps before the development of significant numbers of phenotypically recognizable granules. This recapitulation of a program of sequential expression of primary and secondary granule protein genes suggests that in vitro marrow culture suspensions to which appropriate growth factors are added can mimic normal granulocytic maturation. This system should provide an important model for the study of neutrophil-specific gene expression.

Antigens, CD↗
PubMed1995

Raised plasma arginine vasopressin concentrations during cluster headache attacks.

To obtain data about peripheral concentrations of arginine vasopressin in head pain syndromes, the plasma arginine vasopressin secretory pattern in 12 adult male patients with cluster headache was evaluated. Blood samples for plasma arginine vasopressin and osmolality determinations were collected before, and at 15, 30, 45, 60, 90, and 120 minutes during a cluster attack. Blood pressure was also monitored. The same sampling was repeated during an asymptomatic period. During cluster attacks, the mean values of plasma arginine vasopressin before an attack (2.3 (0.1) ng/l) significantly increased, reaching their peak at 45 minutes (4.8 (0.5) ng/l; P < 0.01 v baseline). No significant variations were found in mean arterial pressure and plasma osmolality. These data suggested involvement of neurotransmitter mechanisms regulating arginine vasopressin secretion and a possible role of arginine vasopressin in vasomotor phenomena accompanying cluster attacks.

Adult↗
PubMed1995

Body sway in diabetic neuropathy.

OBJECTIVE: To evaluate the influence of peripheral neuropathy on body sway assessed by posturography. RESEARCH DESIGN AND METHODS: The age-matched study subjects included 10 insulin-dependent diabetes mellitus (IDDM) patients with peripheral neuropathy (DN), 23 IDDM patients without peripheral neuropathy (D) according to the San Antonio Consensus Conference guidelines, and 21 control subjects (C). All subjects with symptoms and/or clinical signs of postural instability were excluded from the study. RESULTS: The trace surface was significantly larger in the DN than in the C and D groups (P < 0.05), and the trace length was longer in the DN than in the C and D groups (P < 0.01). Mean velocity was faster in the DN than in the other two groups (P < 0.001). A direct relationship was found between the parameters of posturography and some parameters of the nerve conduction velocity. CONCLUSIONS: Diabetic patients with peripheral neuropathy demonstrate a relative deficit in their ability to maintain posture. Posturography allows an early disclosure of the failure of postural control.

Adult↗
PubMed1995

Marrow-derived heparan sulfate proteoglycan mediates the adhesion of hematopoietic progenitor cells to cytokines.

Heparan sulfate proteoglycan (HS-PG), an important component of the human bone marrow extracellular matrix (ECM), is believed to influence hematopoietic progenitor cell development by binding and localizing growth factors to specific niches within the hematopoietic microenvironment. We utilized a model ECM system, which uses immobilized ECM proteins and/or cytokines and bone marrow populations enriched for human hematopoietic stem cell (HSC), to assess the effects of HS-PG on the development of primitive hematopoietic progenitor cells. HS-PG alone failed to bind hematopoietic progenitor cells cloned from bone marrow CD34+CD15-HLA-DR- cells, which are enriched for HSC. HS-PG alone failed to function as a mitogen. In sharp contrast, the interaction of HS-PG with either growth factors (interleukin-3 [IL-3] or stem cell factor/Kit ligand [KL] or an ECM protein (thrombospondin [TSP]) markedly influenced progenitor cell adherence. The binding of either IL-3 or KL to HS-PG resulted in a two-fold increase in attachment of the colony-forming unit-granulocyte/macrophage (CFU-GM), a 1.5-fold increase in attachment of the burst-forming unit-erythroid (BFU-E) and the high-proliferative-potential colony-forming cell (HPP-CFC), and a two- to three-fold increase in attachment of the colony-forming unit-granulocyte/erythroid/macrophage/megakaryocyte (CFU-GEMM) compared to localized growth factor alone. Attachment of the BFU-megakaryocyte (BFU-MK), however, was slightly reduced by the interaction of either IL-3 or KL with HS-PG. The interaction of HS-PG with TSP resulted in a two-fold increase in CFU-GM and CFU-GEMM attachment, while the attachment of BFU-E, HPP-CFC, and BFU-MK was unaltered. We conclude that HS-PG cooperatively interacts with both growth factors and ECM proteins to augment progenitor cell localization within the hematopoietic microenvironment.

Bone Marrow↗
PubMed1995

[Root canal overfilling. Periapical immune reactions].

The authors studied the immunological answer of periapex to look for causes of osteolysis. They did six apicoectomies in teeth with periapical lesions containing extruded material, and found an inflammatory infiltrate of T lymphocytes and macrophages with birifrangent bodies. They suppose that this immunitary answer to extruded material, prevents the periapex cure.

Apicoectomy↗
PubMed1995

[Epidermolysis bullosa. Report and discussion of two clinical cases].

The authors present two clinical cases of epydermolisis bullosa (Hallopeau-Siemens type), to underline characteristic mucous and dental diseases of these types of genodermatosis; they analyze mean diferentiative criteria and the diagnostic possibilities; in the specific treatment of this kind of patient it is important to focus as the therapeutic approach in the different dental fields: so the authors consider therapeutic treatment related to oral and systemic status of the patient examined. From this analysis they give a rational way of approaching this kind of patient both for hygiene and for diet, surgery-prosthetic and restorative treatments.

Adolescent↗
PubMed1994

PE-1, a novel ETS oncogene family member, localizes to chromosome 1q21-q23.

The v-ets oncogene family shares a conserved peptide motif called the ETS domain that mediates sequence-specific DNA binding. This motif is unique among transcription factor families. Using partially degenerate oligonucleotides from conserved regions of the ETS domain and the polymerase chain reaction, we isolated a new member of the v-ets family designated PE-1 from HL60 cells. PE-1 was expressed as an approximately 7.5-kb transcript in most cell lines tested. In the hairy cell leukemia line Eskol, there was an additional 1.8-kb transcript observed. PE-1 was the most common ETS domain gene found in CD34+HLA-DR- hematopoietic progenitors. PE-1 was localized to human chromosome 1q21-q23 using both in situ chromosomal hybridization and human-hamster hybrids.

Amino Acid Sequence↗
PubMed1994

Drosophila Forkhead homologues are expressed in CD34+/HLA-DR- primitive human hematopoietic progenitors.

The Forkhead gene (FKH) regulates morphogenesis in Drosophila. It is the prototype of a new family of transcriptional activators. We used the polymerase chain reaction (PCR) to analyze the expression pattern of this new transcriptional regulatory gene family in primitive hematopoeitic progenitors. Partially degenerate oligonucleotides to two conserved amino acid sequences of this family were used to prime a PCR amplification of cDNA synthesized from CD34+/HLA-DR- hematopoietic cells. Known and novel FKH genes were found to be expressed in these cells.

Animals↗
PubMed1993

Basic fibroblast growth factor promotes the proliferation of human megakaryocyte progenitor cells.

Basic fibroblast growth factor (bFGF), a multifunctional growth factor produced by bone marrow stromal cells, is known to be a potent modulator of hematopoiesis. Because bFGF is present in both human megakaryocytes (MKs) and platelets, we have hypothesized that this growth factor might affect human megakaryocytopoiesis. To test this hypothesis, either low density bone marrow (BM) cells (LDBM), a human BM subpopulation (CD34+ DR+) enriched for the colony-forming unit megakaryocyte (CFU-MK) or a BM subpopulation (CD34+ DR-) enriched for the more primitive burst-forming unit megakaryocyte (BFU-MK) were assayed in the presence of this growth factor. The effect of bFGF on MK colony formation differed according to the cell population assayed. bFGF alone had on MK colony-stimulating activity (MK-CSA) when either CD34+ DR+ or CD34+ DR- BM cells were cloned, but exhibited MK-CSA equivalent to that of interleukin-3 (IL-3) when LDBM cells were used as the target cell population. The MK-CSA of bFGF was inhibited by the addition of neutralizing antisera to either IL-3 and/or granulocyte-macrophage colony-stimulating factor (GM-CSF) but not IL-6. The addition of excess amounts of either IL-3 or GM-CSF to cultures containing bFGF plus anti-IL-3 or anti-GM-CSF reversed the inhibition by the corresponding antisera. The addition of bFGF and IL-3 to assays containing CD34+ DR+ or CD34+ DR- cells increased the size of both CFU-MK- and BFU-MK-derived colonies, respectively, when compared with assays containing IL-3 alone. This increase in MK colony size mediated by bFGF was not affected by addition of either an anti-GM-CSF or anti-IL-6 neutralizing antisera. When LDBM cells were assayed, bFGF alone increased CFU-MK-derived colony size when compared with control values. However, this potentiation of MK colony size by bFGF could be reversed by the addition of either anti-IL-3 or anti-GM-CSF but not anti-IL-6 antisera. In addition, the effects of bFGF and IL-3 on the size of MK colonies cloned from LDBM were not additive. These results suggest that bFGF affects human megakaryocytopoiesis by directly promoting MK progenitor cell proliferation and stimulating BM accessory cells to release growth factor(s) with MK-CSA, such as IL-3 and GM-CSF. We conclude that bFGF, likely produced by cellular components of the BM microenvironment, plays an important role in the control of human megakaryocytopoiesis.

Antibodies↗